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diff --git a/37675.txt b/37675.txt new file mode 100644 index 0000000..5e33874 --- /dev/null +++ b/37675.txt @@ -0,0 +1,8756 @@ +The Project Gutenberg EBook of Arteriosclerosis and Hypertension:, by +Louis Marshall Warfield + +This eBook is for the use of anyone anywhere at no cost and with +almost no restrictions whatsoever. You may copy it, give it away or +re-use it under the terms of the Project Gutenberg License included +with this eBook or online at www.gutenberg.org + + +Title: Arteriosclerosis and Hypertension: + with Chapters on Blood Pressure, 3rd Edition. + +Author: Louis Marshall Warfield + +Release Date: October 12, 2011 [EBook #37675] + +Language: English + +Character set encoding: ASCII + +*** START OF THIS PROJECT GUTENBERG EBOOK ARTERIOSCLEROSIS AND HYPERTENSION: *** + + + + +Produced by Bryan Ness, Julia Neufeld and the Online +Distributed Proofreading Team at http://www.pgdp.net (This +file was produced from images generously made available +by The Internet Archive/American Libraries.) + + + + + + + +Transcriber's Notes: Passages in italics are indicated by _underscores_. + +Passages in bold are surrounded by =. + +Small caps have been replaced by ALL CAPS. + + + + +ERRATUM + + +Page 75, Figure shown is not the Brown sphygmomanometer described in the +text, but the Baumanometer manufactured by W. A. Baum Co., Inc., New +York. It is claimed that the Baumanometer is made with particular care +and hence the readings are said to be more accurate than other mercury +instruments. It is apparently a good instrument. The author has had no +personal experience with it. + + + + + ARTERIOSCLEROSIS + + AND + + HYPERTENSION + + With Chapters on Blood Pressure + + BY + + LOUIS M. WARFIELD, A.B., M.D., (Johns Hopkins), + F.A.C.P. + + FORMERLY PROFESSOR OF CLINICAL MEDICINE, MARQUETTE UNIVERSITY MEDICAL + SCHOOL; CHIEF PHYSICIAN TO MILWAUKEE COUNTY HOSPITAL; ASSOCIATE + MEMBER ASSOCIATION AMERICAN PHYSICIANS; MEMBER AMERICAN + ASSOCIATION PATHOLOGISTS AND BACTERIOLOGISTS; + AMERICAN MEDICAL ASSOCIATION, ETC., FELLOW + AMERICAN COLLEGE OF PHYSICIANS + + _THIRD EDITION_ + + ST. LOUIS + + C. V. MOSBY COMPANY + + 1920 + + COPYRIGHT, 1912, 1920, BY C. V. MOSBY COMPANY + + + _Press of + C. V. Mosby Company + St. Louis_ + + + TO + + MY MOTHER + + THIS VOLUME IS AFFECTIONATELY + + DEDICATED + + + + +PREFACE TO THIRD EDITION + + +Several years have elapsed since the appearance of the second edition of +this book. During this time there has been considerable experimentation +and much writing on arteriosclerosis. The total of all work has not been +to add very much to our knowledge of the etiology of arterial +degeneration. Points of view and opinions change from time to time. It +is so with arteriosclerosis. In this edition arteriosclerosis is not +regarded as a disease with a definite etiologic factor. Rather it is +looked upon as a degenerative process affecting the arteries following a +variety of causes more or less ill defined. It is not considered a true +disease. Possibly syphilitic arteritis may be viewed as an entity, the +cause is known and the lesions are characteristic. + +Much new material and many new figures have been added to this edition. +Some rearranging has been done. The chapter on Blood Pressure has been +much expanded and some original observations have been included. The +literature has been selected rather than indiscriminately quoted. Much +that is written on the subject is of little value. + +It has always seemed to the author that there is not enough of the +personal element in medical writings. At the risk of being severely +criticized, he has attempted to make this book represent largely his own +ideas, only here and there quoting from the literature. + +New chapters on Cardiac Irregularities Associated with Arteriosclerosis, +and Blood Pressure in Its Clinical Application have been added. + +The fact that the book has passed through two editions is very +gratifying and seems to show that it has met with favor. The author +takes this opportunity of thanking those who have loaned him +illustrations. Wherever figures are borrowed due credit is given. + +It is hoped that the kind of reception accorded to the first and second +editions will also not be withheld from this present edition. + + LOUIS M. WARFIELD. + + Milwaukee, Wisc. + + + + +PREFACE TO THE SECOND EDITION + + +In this second edition so many changes and additions have been made that +the book is practically a new one. All the chapters which were in the +previous edition have been carefully revised. Two chapters, "Pathology" +and "Physiology," have been completely rewritten and brought up to date. +It was thought best to add some references for those who had interest +enough to pursue the subject further. These references have been +selected on account of the readiness with which they may be procured in +any library, public or private. Two new chapters have been added--one on +"The Physical Examination of the Heart and Arteries," the other on +"Arteriosclerosis in Its Relation to Life Insurance," and it is hoped +that these will add to the practical value of the book. + +Arteriosclerosis can scarcely be considered apart from blood pressure, +and in the view expressed within, with which some may not concur, high +tension is considered to be a large factor in the production of +arteriosclerosis. As the data on blood pressure have increased, the +importance of it has become more evident. The chapter on "Blood +Pressure" has been wholly rewritten, expanded so as to give a +comprehensive grasp of the essential features, and several illustrations +have been added in order to elucidate the text more fully. The chief +objects in view were to make clear to the physician the technique and +the necessity for estimating both systolic and diastolic pressures. + +The author is grateful for the kindly reception accorded the first +edition. No one is more keenly aware of the imperfections than he. The +necessity for a second edition is taken to mean that the book has found +a place for itself and has been of use to some. + +The author hopes that this new edition will fulfill adequately the +purpose for which he prepared the book--namely, as a practical guide to +the knowledge and appreciation of a most important and exceedingly +common disease. + + LOUIS M. WARFIELD. + + Milwaukee, May, 1912. + + + + +PREFACE TO THE FIRST EDITION + + +It is hoped that this small volume may fill a want in the already +crowded field of medical monographs. The author has endeavored to give +to the general practitioner a readable, authoritative essay on a disease +which is especially an outcome of modern civilization. To that end all +the available literature has been freely consulted, and the newest +results of experimental research and the recent ideas of leading +clinicians have been summarized. The author has supplemented these with +results from his own experience, but has thought it best not to burden +the contents with case histories. + +The stress and strain of our daily life has, as one of its consequences, +early arterial degeneration. There can be no doubt that arterial disease +in the comparatively young is more frequent than it was twenty-five +years ago, and that the mortality from diseases directly dependent on +arteriosclerotic changes is increasing. Fortunately, the almost +universal habit of getting out of doors whenever possible, and the +revival of interest in athletics for persons of all ages, have to some +extent counteracted the tendency to early decay. Nevertheless, the +actual average prolongation of life is more probably due to the very +great reduction in infant mortality and in deaths from infectious and +communicable diseases. + +The wear and tear on the human organism in our modern way of living is +excessive. Hard work, worry, and high living all predispose to +degenerative changes in the arteries, and so bring on premature old age. +The author has tried to emphasize this by laying stress on the +prevention of arteriosclerosis rather than on the treatment of the fully +developed disease. + +No bibliography is given, as this is not intended as a reference book, +but rather as a guide to a better appreciation and understanding of a +most important subject. It has been difficult to keep from wandering off +into full discussions of conditions incident to and accompanied by +arteriosclerosis, but, in order to be clear in his statements and +complete in his descriptions, the author has to invade the fields of +heart disease, kidney disease, brain disease, etc. It is hoped, however, +that these excursions will serve to show how intimately disease of the +arteries is bound up with diseases of all the organs and tissues of the +body. + +Some authors have been named when their opinions have been given. Thanks +are extended also to many others to whom the writer is indebted, but of +whom no individual mention has been made. + +The author also takes this opportunity of expressing his appreciation of +the kindness of Dr. D. L. Harris, who took the microphotographs, and to +the publishers for their unfailing courtesy and consideration. + + LOUIS M. WARFIELD. + + St. Louis, August, 1908. + + + + +CONTENTS + + + PAGE + + CHAPTER I + + ANATOMY 25 + + Introduction, 25; Definition, 26; General Structure of + the Arteries, 27; Arteries, 29; Veins, 30; Capillaries, 31. + + CHAPTER II + + PATHOLOGY 32 + + Syphilitic Aortitis, 44; Experimental Arteriosclerosis, 50; + Arteriosclerosis of the Pulmonary Arteries, 63; Sclerosis + of the Veins, 64. + + CHAPTER III + + PHYSIOLOGY OF THE CIRCULATION 65 + + Blood Pressure, 68; Blood Pressure Instruments, 70; Technic, + 80; Arterial Pressure, 85; Normal Pressure Variations, 88; + The Auscultatory Blood Pressure Phenomenon, 90; The Maximum + and Minimum Pressures, 94; Relative Importance of the + Systolic and Diastolic Pressures, 97; Pulse Pressure, 100; + Blood Pressure Variations, 102; Hypertension, 106; + Hypotension, 117; The Pulse, 123; The Venous Pulse, 123; + The Electrocardiogram, 126. + + CHAPTER IV + + IMPORTANT CARDIAC IRREGULARITIES ASSOCIATED WITH + ARTERIOSCLEROSIS 131 + + Auricular Flutter, 131; Auricular Fibrillation, 133; + Ventricular Fibrillation, 138; Extrasystole, 138; + Heart Block, 140. + + CHAPTER V + + BLOOD PRESSURE IN ITS CLINICAL APPLICATIONS 147 + + Blood Pressure in Surgery, 147; Head Injuries, 148; Shock + and Hemorrhage, 148; Blood Pressure in Obstetrics, 152; + Infectious Diseases, 153; Valvular Heart Disease, 155; + Kidney Disease, 155; Other Diseases, Liver, Spleen, + Abdomen, etc., 156. + + CHAPTER VI + + ETIOLOGY 157 + + Congenital Form, 157; Acquired Form, 159; Hypertension, + 159; Age, Sex, Race, 161; Occupation, 162; Food Poisons, + 163; Infectious Diseases, 163; Syphilis, 165; Chronic + Drug Intoxications, 166; Overeating, 167; Mental Strain, + 168; Muscular Overwork, 169; Renal Disease, 169; Ductless + Glands, 171. + + CHAPTER VII + + THE PHYSICAL EXAMINATION OF THE HEART AND ARTERIES 172 + + Heart Boundaries, 172; Percussion, 174; Auscultation, + 176; The Examination of the Arteries, 177; Estimation + of Blood Pressure, 179; Palpation, 180; Precautions When + Estimating Blood Pressure, 181; The Value of Blood + Pressure, 181. + + CHAPTER VIII + + SYMPTOMS AND PHYSICAL SIGNS 183 + + General, 183; Hypertension, 185; The Heart, 188; Palpable + Arteries, 189; Ocular Signs and Symptoms, 190; Nervous + Symptoms, 191. + + CHAPTER IX + + SYMPTOMS AND PHYSICAL SIGNS 194 + + Special, 194; Cardiac, 195; Renal, 199; Abdominal or + Visceral, 201; Cerebral, 203; Spinal, 205; Local or + Peripheral, 207; Pulmonary Artery, 209. + + CHAPTER X + + DIAGNOSIS 210 + + Early Diagnosis, 210; Differential Diagnosis, 215; + Diseases in Which Arteriosclerosis is Commonly Found, 216. + + CHAPTER XI + + PROGNOSIS 218 + + CHAPTER XII + + PROPHYLAXIS 224 + + CHAPTER XIII + + TREATMENT 229 + + Hygienic Treatment, 230; Balneotherapy, 233; Personal + Habits, 234; Dietetic Treatment, 235; Medicinal, 238; + Symptomatic Treatment, 245. + + CHAPTER XIV + + ARTERIOSCLEROSIS IN ITS RELATION TO LIFE INSURANCE 249 + + CHAPTER XV + + PRACTICAL SUGGESTIONS 256 + + + + +ILLUSTRATIONS + + + FIG. PAGE + + 1. Cross section of a large artery 28 + + 2. Cross section of a coronary artery 36 + + 3. Arteriosclerosis of the thoracic and abdominal aorta 39 + + 4. Arteriosclerosis of the arch of the aorta 40 + + 5. Normal aorta 41 + + 6. Radiogram showing calcification of both radial and ulnar + arteries 42 + + 7. Syphilitic aortitis of long standing 44 + + 8. Diagrammatic representation of strain hypertrophy 48 + + 9. Strain hypertrophy 49 + + 10. Cross section of small artery in the mesentery 56 + + 11. Enormous hypertrophy of left ventricle 58 + + 12. Aortic incompetence with hypertrophy and dilatation of + left ventricle 61 + + 13. Cook's modification of Riva-Rocci's blood pressure + instrument 72 + + 14. Stanton's sphygmomanometer 73 + + 15. The Erlanger sphygmomanometer with the Hirschfelder + attachments 74 + + 16. Desk model Baumanometer 75 + + 17. Faught blood pressure instrument 76 + + 18. Rogers' "Tycos" dial sphygmomanometer 77 + + 19. Detail of the dial in the "Tycos" instrument 78 + + 20. Faught dial instrument 79 + + 21. Detail of the dial of the Faught instrument 79 + + 22. The Sanborn instrument 80 + + 23. Method of taking blood pressure with a patient in sitting + position 81 + + 24. Method of taking blood pressure with patient lying down 82 + + 25. Observation by the auscultatory method and a mercury + instrument 84 + + 26. Observation by the auscultatory method and a dial instrument 85 + + 27. Schema to illustrate decrease in pressure 86 + + 28. Chart showing the normal limits of variation in systolic + blood pressure 89 + + 29. Tracing of auscultatory phenomena 94 + + 30. Tracing of auscultatory phenomena 95 + + 31. Clinical determination of diastolic pressure, fast drum 96 + + 32. Clinical determination of diastolic pressure, slow drum 96 + + 33. Venous blood pressure instrument 121 + + 34. New venous pressure instrument 122 + + 35. Events in the cardiac cycle 124 + + 36. Simultaneous tracings of the jugular and carotid pulses 125 + + 37. Jugular and carotid tracings 125 + + 38. Right side of the heart showing distribution of the + two vagus nerves 127 + + 39. Normal electrocardiogram 128 + + 40. Auricular flutter 132 + + 41. Auricular fibrillation 134 + + 42. Auricular fibrillation 134 + + 43. Pulse deficit 135 + + 44. Ventricular fibrillation 137 + + 45. Auricular extrasystoles 139 + + 46. Ventricular extrasystole 139 + + 47. Delayed conduction 141 + + 48. Partial heart block 141 + + 49. Complete heart block 142 + + 50. Alternating periods of sinus rhythm and + auriculoventricular rhythm 144 + + 51. Auriculoventricular or "nodal" rhythm 144 + + 52. Influence of mechanical pressure on the right vagus nerve 144 + + 53. Schematic distribution of right and left vagus 145 + + 54. Blood pressure record from a normal reaction to ether 149 + + 55. Chart showing the method of recording blood pressure + during an operation 150 + + 56. Method of using blood pressure instrument during operation 151 + + 57. Finger-tip palpation of the radial artery 178 + + 58. Finger-tip palpation of the radial artery 178 + + 59. Aneurysm of the heart wall 196 + + 60. Large aneurysm of the aorta eroding the sternum 198 + + + + +ARTERIOSCLEROSIS AND HYPERTENSION + + + + +CHAPTER I + +ANATOMY + + +With the increased complexity of our modern life comes increased wear +and tear on the human organism. "A man is as old as his arteries" is an +old dictum, and, like many proverbs, the application to mankind today +is, if anything, more pertinent than it was when the saying was first +uttered. Notwithstanding the fact that the average age of mankind at +death has been materially lengthened--the increase in years amounting to +fourteen in the past one hundred years of history--clinicians and +pathologists are agreed that the arterial degeneration known as +arteriosclerosis is present to an alarming extent in persons over forty +years of age. Figures in all vital statistics have shown us that all +affections of the circulatory and renal systems are definitely on the +increase. "Arterial diseases of various kinds, atheroma, aneurysm, etc., +caused 15,685 deaths in 1915, or 23.3 per 100,000. This rate, although +somewhat lower than the corresponding ones for 1912 and 1913, is higher +than that for 1914, and is very much higher than that for 1900, which +was 6.1." + +The great group of cases of which cardiac incompetence, aneurysm, +cerebral apoplexy, chronic nephritis, emphysema, and chronic bronchitis +are the most frequent and important appear as terminal events in which +arteriosclerosis has probably played an important part. + +Thus, in the sense in which we speak of tuberculosis or pneumonia as a +distinct disease, we can not so designate the diseased condition of the +arteries. + +Arteriosclerosis is not a disease =sui generis=. It is best viewed as a +degeneration of the coats of the arteries, both large and small +resulting in several different more or less distinct types. + +These types blend one into the other and in the same patient all types +may be found. Thus the sclerosis of the arteries is the result of a +variety of causes, none of which is definitely known in the sense of a +bacterial disease. As we shall see later, one type of arteriosclerosis +has a special pathology and etiology, the syphilitic arterial changes. + +Bearing in mind that arteriosclerosis (called by some "arteriocapillary +fibrosis," by others "atherosclerosis") is not a true disease, it may, +for convenience be defined as a chronic disease of the arteries and +arterioles, characterized anatomically by increase or decrease of the +thickness of the walls of the blood vessels, the initial lesion being a +weakening of the middle layer caused by various toxic or mechanical +agencies. This weakness of the media leads to secondary effects, which +include hypertrophy or atrophy of the inner layer--and not infrequently +hypertrophy of the outer layer--connective tissue formation and +calcification in the vessels, and the formation of minute aneurysms +along them. The term arteriocapillary fibrosis has a broader meaning, +but is a cumbersome phrase, and conveys the idea that the capillary +changes are an essential feature of the process, whereas these are for +the most part secondary to the changes in the arteries. The veins do not +always escape in the general morbid process, and when these are affected +the whole condition is sometimes called vascular sclerosis or +angiosclerosis. + +Upon the anatomical structure of the arteries depends, as a rule, the +character and extent of the arteriosclerotic lesions. For the clear +comprehension of the process, it is necessary to keep in mind the +essential histological differences between the aorta and the larger and +smaller branches of the arterial tree. + +The vascular system is often likened to a central pump, from which +emanates a closed system of tubes, beginning with one large +distributing pipe, which gives rise to a series of tubes, whose number +is constantly increasing at the same time that their caliber is +decreasing in size. From the smallest of these tubes, larger and larger +vessels collect the flowing blood, until, at the pump, two large trunks +of approximately the same area as the one large distributing trunk empty +the blood into the heart, thus completing the circle. This is but a +rough illustration, and, while possibly useful, takes into account none +of the vital forces which are constantly controlling every part of the +distributing system. + + +General Structure of the Arteries + +The aorta and its branches are highly elastic tubes, having a smooth, +glistening inner surface. When the arteries are cut open, they present a +yellowish appearance, due to the large quantity of elastic tissue +contained in the walls. The elasticity is practically perfect, being +both longitudinal and transverse. The essential portion of any blood +vessel is the endothelial tube, composed of flat cells cemented together +by intercellular substance and having no stomata between the cells. This +tube is reinforced in different ways by connective tissue, smooth muscle +fibers, and fibroelastic tissue. Although the gradations from the larger +to the smaller arteries and from these to the capillaries and veins are +almost insensible, yet particular arteries present structural characters +sufficiently marked to admit of histological differentiation. + +The whole vascular system, including the heart, has an endothelial +lining, which may constitute a distinct inner coat, the tunica intima, +or may be without coverings, as in the case of the capillaries. The +intima (Fig. 1) consists typically of endothelium, reinforced by a +variable amount of fibroelastic tissue, in which the elastic fibers +predominate. The tunica media is composed of intermingled bundles of +elastic tissue, smooth muscle fibers, and some fibrous tissue. The +adventitia or outer coat is exceedingly tough. It is usually thinner +than the media, and is composed of fibroelastic tissue. This division +into three coats is, however, somewhat arbitrary, as in the larger +arteries particularly it is difficult to discover any distinct +separation into layers. + +[Illustration: Fig. 1.--Cross section of a large artery showing the +division into the three coats; intima, media, adventitia. The intima is +a thin line composed of endothelial cells. The wavy elastic lamina is +well seen. The thick middle coat is composed of muscle fibers and +fibroelastic tissue. The loose tissue on the outer (lower portion of +cut) side of the media is the adventitia. (Microphotograph, highly +magnified.)] + +The muscular layer varies from single scattered cells, in the +arterioles, to bands of fibers making up the body of the vessel in the +medium-sized arteries and veins. + +There is elastic tissue in all but the smallest arteries, and it is also +found in some veins. It varies in amount from a loose network to dense +membranes. In the intima of the larger arteries the elastic tissue +occurs as sheets, which under the microscope appear perforated and +pitted, the so-called fenestrated membrane of Henle. + +The nutrient vessels of the arteries and veins, the vasa vasorum, are +present in all the vessels except those less than one millimeter in +diameter. The vasa vasorum course in the external coat and send +capillaries into the media, supplying the outer portion of the coat and +the externa with nutritive material. The nutrition of the intima and +inner portion of the media is obtained from the blood circulating +through the vessel. Lymphatics and nerves are also present in the middle +and outer layers of the vessels. + + +Arteries + +The structure of the arteries varies notably, depending upon the size of +the vessel. A cross section of the thoracic aorta reveals a dense +network of elastic fibers, occupying practically all of the space +between the single layer of endothelial cells and the loose elastic and +connective tissue network of the outer layer. Smooth muscle fibers are +seen in the middle coat, but, in comparison with the mass of elastic +tissue, they appear to have only a limited function. + +In a cross section of the radial artery one sees a wavy outline of +intima, caused by the endothelium following the corrugations of the +elastica. The endothelium is seen as a delicate line, in which a few +nuclei are visible. The media is comparatively thick, and is composed of +muscle cells, arranged in flat bundles, and plates of elastic tissue. +Between the media and the externa the elastic tissue is somewhat +condensed to form the external elastic membrane. The adventitia varies +much in thickness, being better developed in the medium-sized than in +the large arteries. It is composed of fibrous tissue mixed with elastic +fibers. + +"Followed toward the capillaries, the coats of the artery gradually +diminish in thickness, the endothelium resting directly upon the +internal elastic membrane so long as the latter persists, and afterward +on the rapidly attenuating media. The elastica becomes progressively +reduced until it entirely disappears from the middle coat, which then +becomes a purely muscular tunic, and, before the capillary is reached, +is reduced to a single layer of muscle cells. In the precapillary +arterioles the muscle no longer forms a continuous layer, but is +represented by groups of fiber cells that partially wrap around the +vessel, and at last are replaced by isolated elements. After the +disappearance of the muscle cells the blood vessel has become a true +capillary. The adventitia shares in the general reduction, and gradually +diminishes in thickness until, in the smallest arteries, it consists of +only a few fibroelastic strands outside the muscle cells." (Piersol's +Anatomy.) + +The large arteries differ from those of medium size mainly in the fact +that there is no sharp line of demarcation between the intima and the +media. There is also much more elastic tissue distributed in firm +bundles throughout the media, and there are fewer muscle fibers, giving +a more compact appearance to the artery as seen in cross section. The +predominance of elastic tissue permits of great distention by the blood +forced into the artery at every heartbeat, the caliber of the tube being +less markedly under the control of the vasomotor nerves than is the case +in the small arteries, where the muscle tissue is relatively more +developed. The adventitia of the large arteries is strong and firm, and +is made up of interlacing fibroelastic tissue, of which some of the +bundles are arranged longitudinally. + + +Veins + +The walls of the veins are thinner than those of the arteries; they +contain much less elastic and muscular tissue, and are, therefore, more +flaccid and less contractile. Many veins, particularly those of the +extremities, are provided with cup-like valves opening toward the heart. +These valves, when closed, prevent the return of the blood to the +periphery and distribute the static pressure of the blood column. The +bulgings caused by the valves may be seen in the superficial veins of +the arm and leg. There are no valves in the veins of the neck, where +there is no necessity for such a protective mechanism, gravity sufficing +to drain the venous blood from the cranial cavity. + + +Capillaries + +These are endothelial tubes in the substance of the organs, the tissue +of the organ giving them the necessary support. They are the final +subdivisions of the blood vessels, and the vast capillary area offers +the greatest amount of resistance to the blood flow, thus serving to +slow the blood stream and allowing time for nutritive substances or +waste products to pass from and to the blood. Usually the capillaries +are arranged in the form of a network, the channels in any one tissue +being of nearly uniform size, and the closeness of the mesh depending +upon the organ. + +As far back as 1865, Stricker observed contraction of the capillaries. +This observation was apparently forgotten until revived again by Krogh +recently. The latter finds that the capillaries are formed of cells +which are arranged in strands encircling the vessel. The capillaries are +rarely longer than 1 mm., and, according to Krogh, are capable of +enormous dilatation. + +The rate of flow through any capillary area is very inconstant, and the +usual explanation has been that the capillaries were endothelial tubes +the blood flow of which was dependent upon the contraction or dilatation +of the terminal arterioles. The actual fact that in an observed +capillary area some capillaries are empty renders the above explanation +untenable. The color of a tissue depends upon the state of filling of +the capillaries with blood. + +It would seem that all the evidence now leads us to believe that the +capillaries themselves are contractile and it is even possible that they +may be under vasomotor control. If the anatomic structure as stated +above, is correct, it would take but a slight contraction of the +encircling cell to shut off completely the capillary. When the enormous +capillary bed is considered, it is not inconceivable that circulating +poisons may act on large areas and produce a true capillary resistance +to the onflow of blood which might express itself, if long continued, in +actual hypertrophy of the heart. + + + + +CHAPTER II + +PATHOLOGY + + +The whole subject of the pathology of arteriosclerosis has been much +enriched by the study of the experimental lesions produced by various +drugs and microorganisms upon the aortas of rabbits. Simple atheroma +must not be confused with the lesions of arteriosclerosis. The small +whitish or yellowish plaques so frequently seen on the aorta and its +main branches, may occur at any age, and have seemingly no great +significance. Such plaques may grow to the size of a dime or larger, and +even become eroded. They represent fatty degeneration of the intima +which, at times, has no demonstrable cause; at times follows in the +course of various diseases, and undoubtedly is due to disturbances of +nutrition in the intima. Except for the remote danger of clot formation +on the uneven or eroded spot, these places are of no special +significance, and are not to be confused with the atheroma of nodular +sclerosis. + +The lesions of arteriosclerosis are of a different character. It has +been customary to differentiate three types: (1) nodular; (2) diffuse; +(3) senile. It must be understood that this is not a classification of +distinct types. As a rule in advanced arteriosclerosis, lesions +representing all types and all grades are found. The nodular type, +however, may occur in the aorta alone, the branches remaining free. This +is most often found in syphilitic sclerosis where the lesion is confined +to the ascending portion of the arch of the aorta. + +The retrogressive changes of advancing years can not be rightly termed +disease, yet it becomes necessary to regard them as such, for the senile +changes, as we shall see, may be but the advanced stages of true +arteriosclerosis. Much depends on the nature of the arterial tissue and +much on the factors at work tending to injure the tissue. A man of +forty years may therefore have the calcified, pipe stem arteries of a +man of eighty. Our parents determine, to great extent, the kind of +tissue with which we start life. The arteries are elastic tubes capable +of much stretching and abuse. In the aorta and large branches there is +much elastic tissue and relatively little muscle. When the vessels have +reached the organs, they are found to be structurally changed in that +there is in them a relatively small amount of elastic tissue but a great +deal of smooth muscle. This is a provision of nature to increase or +decrease the supply of blood at any point or points. + +The aorta and the large branches are distributing tubes only. It is +after all in the arterioles and smaller arteries that the lesions of +arteriosclerosis do the most damage. A point to be emphasized is that +the whole arterial system is rarely, if ever, attacked uniformly. That +is, there may be a marked degree of sclerosis in the aorta and coronary +arteries with very little, if any, change in the radials. On the +contrary, a few peripheral arteries only may be the seat of disease. A +case in point was seen at autopsy in which the aorta in its entirety and +all the large peripheral branches were absolutely smooth. In the brain, +however, the arteries were tortuous, hard, and were studded with miliary +aneurysms. It is not possible to judge accurately the state of the whole +arterial system by the stage of the lesion in any one artery; but on the +whole one may say that an undue thickening of the radial artery +indicates analogous changes in the mesenteric arteries and in the aorta. + +So far as the anatomical lesions in the aorta and branches are +concerned, there is much uniformity even though the etiologic factors +have been diverse. The only difference is one of extent. To Thoma we owe +the first careful work on arteriosclerosis. He regarded the lesion in +arteriosclerosis as one situated primarily in the media; there is a lack +of resistance in this coat. His views are now chiefly of historical +interest. As the author understands him, he considered a rupture in the +media to be the cause of a local widening and consequently the blood +could not be distributed evenly to the organ which was supplied by the +diseased artery or arteries. Moreover, there was danger of a rupture at +the weak spot unless this were strengthened. It was essential for the +even distribution of blood that the lumen be restored to its former +size. Nature's method of repair was a hypertrophy of the subintimal +connective tissue and the formation of a nodule at that point. The +thickening was compensatory, resulting in the establishment of the +normal caliber of the vessel. Thoma showed that by injecting an aorta in +the subject of such changes, with paraffin at a pressure of 160 mm. of +mercury, these projections disappeared and the muscle bulged externally. +He recognized the fact that the character of the artery changed as the +years passed, and to this form he gave the name, primary +arteriosclerosis. To the group of cases caused by various poisonous +agents, or following high peripheral resistance and consequent high +pressure, he gave the name, secondary arteriosclerosis. This is a useful +but not essential division, as the changes which age and high tension +produce may not be different from those produced in much younger persons +by some circulating poison. And most important to bear in mind, +octogenarians may have soft, elastic arteries. + +As the body ages, certain changes usually take place in the arteries +leading to thickening and inelasticity of their walls. This is a normal +change, and in estimating the palpable thickening of an artery, such as +the radial, the age of the individual must always be considered. + +Thayer and Fabyan, in an examination of the radial artery from birth to +old age, found that, in general, the artery strengthens itself, as more +strain is thrown upon it, by new elastica in the intima and connective +tissue in the media and adventitia. Up to the third decade there is +only a strengthening of the media and adventitia. During the third and +fourth decades there is also distinct connective tissue thickening in +the intima. "In other words, the strain has begun to tell upon the +vessel wall, and the yielding tube fortifies itself by the connective +tissue thickening of the intima and to a lesser extent of the media." By +the fifth decade the connective tissue deposits in the intima are +marked, there is an increase of fibrous tissue upon the medial side of +the intima and, in lesser degree, throughout the media. "Finally, in +these sclerotic vessels degenerative changes set in, which are somewhat +different from those seen in the larger arteries, consisting, as they +do, of local areas of coagulation necrosis with calcification, +especially marked in the deep layers of the connective tissue +thickenings of the intima, and in the muscle fibers of the media, +particularly opposite these points. These changes may ... go on to +actual bone formation." The mesenteric artery differs in some respects +from the radial, but in the main, the changes brought about by age are +the same. Thayer and Fabyan note two striking points of difference: "(1) +calcification is apparently much less frequent than in the radials; (2) +in several cases plaques were seen with fatty softening of the deeper +layers of the intima and superficial proliferation--a picture which we +have never seen in the radial." (See Fig. 2.) + +[Illustration: Fig. 2.--Cross-section of a coronary artery, x50, showing +nodular sclerosis. Note the heaping up of cells in the intima, the +fracture of the elastica, and the destruction of the media beneath the +nodule. The primary lesion evidently was in the media. The thickened +intima is the effort on the part of nature to heal the breach. At such +places as shown here aneurysms may form. (Microphotograph.)] + +Aschoff's studies of the aorta show that, "in infancy the elastic laminae +of the media stand out sharply defined, well separated from each other +by the muscle layers, which are well developed.... From childhood there +is to be observed a slowly progressive increase in the elastic elements +of the media. Not only do the individual lamellae seen in cross-sections +become thicker, but also they afford an increasing number of fine +secondary filaments feathering off from these and crossing the muscle +layer, so that now they are no longer sharply defined, but more ragged +upon cross-section. This progressive increase attains its maximum at or +about the age of thirty-five, and from now on for the next fifteen +years the condition is relatively stationary. After fifty there is to be +observed a slowly progressive atrophy of the elastica. The media becomes +obviously thinner and presumably weaker." (Adami.) It has also been +found (Klotz) that after the age of thirty-five, the muscle of the media +begins to exhibit fatty degeneration which after fifty years is well +marked. The fatty degeneration may then give place to a calcareous +infiltration or the fibers may undergo complete absorption. It would +appear that the thinning of the aortic media is due not so much to the +atrophy of the elastic tissue as to that of the muscle tissue. The +elastic tissue does lose its specific property and the artery thus +becomes practically a connective tissue tube. + +Scheel has made very careful measurements of the ascending, the +thoracic, and the abdominal aorta, and the pulmonary artery. He found +that from birth to sixty years, the aorta became progressively wider and +lost its elasticity. The pulmonary changed little, if at all, after +thirty to forty years, and where before it was wider than the aorta, it +now was found to be smaller. In chronic nephritis both were widened. The +continuous increase of width and length of the aorta stands in reverse +relationship to the elasticity of its walls. + +Although the division of the lesions into nodular, diffuse, and senile +has been the usual one, it is better to separate three groups into (1) +nodular, (2) diffuse or senile, and (3) syphilitic. There is more known +about the histology of the syphilitic form and the lesions which consist +of puckerings and scars seen on opening an aorta just above the valves, +and on the ascending portion of the arch are characteristic. A +macroscopic examination suffices in most cases for a definite diagnosis. + +In the nodular form the lesions are found on the aorta and large +branches particularly at or near the orifices of branching vessels. +These nodules may increase in size, forming rather large, slightly +raised plaques of yellowish-white color. They are, as a rule, +irregularly scattered throughout the aorta and branches and tend to be +more numerous and larger in the abdominal aorta. The initial lesion is +in the media, consisting of an actual dissolution of this coat with +rupture of the elastic fibers and infiltration with small round cells. +There is thus a weak spot in the artery. Hypertrophy of the intimal +cells takes place, layer upon layer being added in an attempt to +strengthen the vessel at the injured place. Coincidently with this, +there is thickening by a connective tissue growth in the adventitia. The +process begins, at least in syphilis, around the terminals of the vasa +vasorum. It will be recalled that the blood supply of the inner portion +of the media comes from within the vessel itself. As the intimal growth +increases, the blood supply is cut off. The inevitable result is +softening of the portion farthest from the lumen of the vessel. As a +rule there has been a sufficient growth of connective tissue in the +media and adventitia to repair the damage done to the media. This +softening and dissolution gives rise to a granular debris composed of +degenerated cells and fat. This is the so-called atheromatous abscess. +There are no leucocytes as in ordinary pus. These "abscesses" are +frequent and in rupturing leave open ulcers with smooth bases, the +atheromatous ulcer. A further change which often takes place is +calcification of the bases of the ulcers and calcification of the +softened spots before rupture takes place. This only occurs in advanced +cases. (See Fig. 3.) + +[Illustration: Fig. 3.--Arteriosclerosis of the thoracic and abdominal +aorta, showing irregular nodules, atheromatous plaques, denudation of +the intima, thin plates of bone scattered throughout with spicules +extending into the lumen of the vessel. Note the contraction of the +openings of the large branches, the rough appearance of the aorta and +the greater degree of sclerosis of the upper two-thirds, i. e., of the +aorta above the diaphragm. This aorta in the recent state was much +thickened and almost inelastic.] + +[Illustration: Fig. 4.--Arteriosclerosis of the arch of the aorta. +Numerous calcified plaques, thickening and curling of the aortic valves, +giving rise to insufficiency of the aortic valves. The aortic ring is +rigid and not much dilated. (Milwaukee County Hospital.)] + +[Illustration: Fig. 5.--Normal aorta. Compare with Fig. 3. Note the +perfectly smooth, glossy appearance of the intima. The openings of all +the intercostal arteries are distinctly seen. In the recent state this +artery was highly elastic, capable of much stretching both transversely +and longitudinally.] + +Rather contrary to what one would expect, there are no new capillaries +advancing from the media to the intima in the nodular form of +arteriosclerosis, consequently there is no granulation tissue to heal +and leave scars. It must be borne in mind that these changes rarely, if +ever, are the only ones found throughout the arterial system. +Nevertheless, the manifold changes, as will be shown within, appear to +be but stages of one primary process. + +The character of the changes which are known as diffuse arteriosclerosis +seems to have, at first sight, little in common with those of the +nodular sclerosis. The aorta may or may not have plaques of nodular +sclerosis, while the arteries, such as the radial or temporal, may be +beaded or pipe stem in hardness. In spite of these far advanced +peripheral lesions the aorta may appear smooth but it is markedly +dilated, particularly the thoracic portion, it is noticeably thinned +even on macroscopic examination, it has elongated as evidenced by its +slight tortuosity, and it has lost the greater part of its elasticity. +The abdominal aorta is not so extensively affected, although this, too, +shows some elongation and slight thinning. This is considered by some +pathologists to be the uncomplicated form of the so-called senile +arteriosclerosis. It is more of the nature of a degenerative change, it +is true, but, as will be shown later, it has its beginnings, at times, +in comparatively young persons and its etiology is not simple. This +type has been studied most carefully by Moenckeberg, who showed that on +the large branches of the aorta there were depressions due to a +degeneration of the middle coat. These depressions encircled the vessel +to a greater or lesser extent, causing small bulgings at such places +and giving to the vessel a beaded appearance. On viewing such an artery +held to the light, the sacculated spots are seen to be much thinner than +the contiguous normal artery. Associated with such changes in the aorta +and large branches is marked sclerosis of the smaller arteries. Intimal +fibrosis is common, together with hypertrophy and fibrosis of the middle +coat. Not infrequently periarterial thickening is also seen. +Calcification of the media is found and is said to be preceded by +hypertrophy of the middle coat. + +Pure cases of this, the so-called Moenckeberg type, are seen but seldom. +Most commonly there are nodules and plaques in the aorta and large +branches together with thinning and sacculation of other portions of the +vessels' walls. While the two processes appear at a glance to be so +different from each other, it is possible for them to have a common +origin. The initial lesion is in the media but the resulting sclerotic +changes depend upon the kind of vessel, the strength of the coats, the +pressure in the vessel, and other causes. + +Thus the sclerosis of the radials of such an extent that these arteries +are easily palpable, appears to be a different process from that of the +sclerosis in the aorta, yet fundamentally it is the same. The difference +lies in the anatomic structure of the two vessels, and possibly also in +the degree of stretching and strain to which the vessels are subjected +at every heart beat. In the radial artery the media as usual is affected +first. The muscle cells undergo degeneration and either marked +thickening takes place or sacculation results, depending upon the +severity of the exciting cause. Calcification of the media is common. +This occasionally takes the form of rings encircling the vessel, and +gives to the examining finger the sensation of feeling a string of fine +beads. There may be calcification of the subintimal tissue without +deposits of lime salts in the media, but this is more commonly found in +the larger arteries. When the calcification occurs in plates through the +media, the well known pipe stem vessel is produced. (Fig. 6.) + +[Illustration: Fig. 6.--Radiogram of a man aged seventy-five, showing +calcification of both radial and ulnar arteries.] + +The senile sclerosis found in old people is usually a combination of the +Moenckeberg type in the large and medium-sized arteries, and the nodular +type in the aorta, leading eventually to calcareous intimal deposits, +and widened, elongated, inelastic aorta. + + +=Syphilitic Aortitis= + +[Illustration: Fig. 7.--Syphilitic aortitis of long standing. The aortic +valves are curled and thickened, the heart is enlarged and the cavity of +the left ventricle is dilated. (Milwaukee County Hospital.)] + +The seat of election of the syphilitic poison is in the aorta just above +the aortic valves, Fig. 7, and in the ascending portion of the arch. +There are semitranslucent, hyaline-like plaques which have a tendency to +form into groups and, instead of undergoing an atheromatous change as +in the ordinary nodular form of arteriosclerosis, they are prone to scar +formation with puckering, so that macroscopically the nature of the +process may, as a rule, be readily diagnosed. Microscopically the +process is found to be a subacute inflammation of the media, which has +been called a mesaortitis. There is marked small celled infiltration +around some of the branches of the vasa vasorum and there appears to be +actual absorption of the tissue elements of the middle coat. This is +accompanied by hypertrophy of the intimal tissue. There follows +degeneration in the deeper portions of this new tissue and new +capillaries are formed which have their origin in the inflammatory area +in the media. As is everywhere the case throughout the body, granulation +tissue in the process of healing contracts and forms scars. This +explains the scar formation in the aorta. When the process is more +acute, instead of there being a reparative attempt on the part of the +intima, there is actual stretching of the wall at the weakened spot and +there results an aneurysmal dilatation. =Spirochetae pallidae= have been +found in the degenerated media and in small gummata which were situated +beneath the intima. Within the past years it has been found that a large +percentage of patients with cardiovascular disease give the Wassermann +reaction. In cases of aortic insufficiency, the reaction is present in +almost every case. This is in marked contrast to the cases of diffuse +endocarditis where the reaction is rarely present. + +According to Adami the effects of syphilis upon the aorta are the +following: (1) the primary disturbance is a granulomatous, inflammatory +degeneration of the media; (2) this leads to a local giving way of the +aorta; (3) if this be moderate it results in a strain hypertrophy of the +intima and of the adventitia, with the development of a nodose intimal +sclerosis; (4) if it be extreme, there results, on the contrary, an +overstrain atrophy of the intima and aneurysm formation; (5) the intimal +nodosities are here not of an inflammatory type and are nonvascular, +although, with the progressive laying down of layer upon layer of +connective tissue on the more intimal aspect of the intima, the earlier +and deeper-placed layers of new tissue gain less and less nourishment, +and so are liable to exhibit fatty degeneration and necrosis; (6) these +products of necrosis exert a chemotactic influence upon the nearby +vessels of the medial granulation tissue, with, as a result, (a) a +secondary and late entrance of new vessels into the early and +deeply-placed atheromatous area, (b) absorption of the necrotic +products, (c) replacement by granulation tissue, (d) contraction of the +granulation tissue, and (e) depression and scarring of the sclerotic +nodules so characteristic of syphilitic sclerosis. + +In the smaller arteries and arterioles the arteriosclerotic process +appears on superficial examination to be a different process from that +in the aorta and large arteries, but the difference is only apparent. It +will be recalled that there is relatively much more muscle tissue in the +arterioles than in the large arteries. The size, of course, is much +less. Large nodular plaques are not possible. The atheromatous +degeneration is not marked. In the smaller muscular arteries is seen the +intimal proliferation, the stretching of the Moenckeberg type, and the +calcification of the media rather than the intima. The media is thinned +beneath the marked intimal proliferation so that the artery exhibits +translucent areas when held to the light. Again, there is seen +degeneration of the muscle and replacement by connective tissue with or +without hypertrophy of the intima. In the arterioles three kinds of +changes occur: a muscular hypertrophy; a fibrosis of all the coats; or a +marked proliferation of the intimal endothelium. The last two are +probably the same process, the connective tissue having its origin in +the proliferated endothelial cells. Such a deposition of layer upon +layer of cells in an arteriole and the resulting fibrosis leads to the +condition of disappearance of the lumen of the vessel, endarteritis +obliterans. This obliterating endarteritis is not, of course, due alone +to syphilis. Syphilis is only a type of poison which produces such +changes as have been described above. It is in the organs such as the +kidney, liver, spleen, and intestines that one sees the most perfect +examples of this obliterating endarteritis. Endarteritis deformans is a +term applied to the condition of the arteries as a result of irregular +thickenings and deposits of lime salts in the walls. These changes give +rise to marked tortuosity of the vessels. + +Occasionally such an obliterating process takes place in a larger +artery. A thrombus forms and by a process of central softening, new +channels permeate the thrombus, thus restoring to some extent the +function of the vessel. + +That the same process leads at one time to thinning and at another time +to thickening of the arterial walls has been noted above. Prof. Adami +holds that the regular development of layer upon layer of new connective +tissue is non-inflammatory. He calls it a "strain hypertrophy." It is +analogous to the localized hypertrophy of bone where the muscle tendons +are attached, as is so frequently seen in athletes. The increased +tension on connective tissue, provided that it is not overstrained, +leads to its overgrowth, but only when there is sufficient nourishment. +Such conditions are adequately fulfilled in the arteries. When a local +giving way under pressure occurs in the media, the intima is put on the +stretch (see Fig. 8), and there results a hypertrophy of the intima +until the volume of the new tissue and the resistance which this affords +to the mean distending force, balances the loss sustained by the +weakened media. When the balance is struck, the hypertrophy is arrested. +The youngest tissue is thus found directly beneath the endothelium. Now +should this local weakening of the media have an acute origin, instead +of a stimulus to growth there is overstrain, and there is, in +consequence, not hypertrophy but atrophy. The beginning process is here +a mesaortitis, but the acuteness of the poison, and the pressure from +within the artery so stretches the artery that there is no compensatory +hypertrophy, but a thinning, and the ground is prepared for aneurysmal +dilatation or pouching. + +[Illustration: Fig. 8.--I, media weakened at M' with overgrowth of +intima filling in the depression. II, with postmortem rigor and +contraction of the muscles of the media and removal of the blood +pressure from within, the stretched media at M'' contracts; the intimal +thickening thus projects into the arterial lumen. (After Adami.)] + +Again, one not infrequently encounters intimal nodosities when the +underlying media appears of normal thickness. The explanation of this +apparent exception is that the media in the living aorta is actually +thinned, but the layers of subintimal tissue deposited over the weak +spot due to strain hypertrophy become bulged inward when the pressure is +relieved, as at postmortem. The media has not lost all of its elasticity +(see Fig. 9), hence it contracts and there is the appearance of a nodule +on the intima beneath which is a media equal in thickness to that of the +healthy surrounding media. + +[Illustration: Fig. 9.--Schematic representation of the increased strain +brought to bear upon the cells of the intima, Int., when the media, +Med., undergoes a localized expansion through relative weakness. (After +Adami.)] + +The essential lesion in arteriosclerosis of the aorta and large arteries +is a degeneration in the middle coat. This may be brought about by a +variety of poisons circulating in the body. In syphilis, for example, +the initial lesion has been shown to be a mesaortitis. The media seems +to be dissolved, the artery is consequently thinned, there is actual +depression along the level of the vessel. The elastic fibers disappear +and small-celled infiltration takes its place. The intima hypertrophies, +layer upon layer being added in an attempt to restore the strength of +the vessel. There is also, as a rule, rather pronounced hypertrophy of +the adventitia. + + +=Experimental Arteriosclerosis= + +Within the past few years many workers have attempted by various means, +to produce arterial lesions in animals, chiefly rabbits and dogs. The +present status is somewhat chaotic, some affirming and some denying that +arterial changes follow the various methods employed. Following the +injection of small, repeated doses of adrenalin over a certain period of +time, changes occur in the arteries of rabbits which are +arteriosclerotic in type, the essential lesion being a degeneration of +the muscular and elastic tissue of the media with the consequent +production of aneurysm in the vessel. This is said by some to be quite +like the type of arteriosclerosis in man which has been so well +described by Moenckeberg. The degenerations in the arteries following +the experimental lesions are of the nature of a fatty metamorphosis, and +later proceed to calcification. Barium chloride, digitalin, +physostigmin, nicotin and other substances, as well as adrenalin, have +been found to exert a selective toxic action on the muscle cells of the +middle coat of the aorta. The infundibular portion of the pituitary +body, the portion which is developed from the infundibulum of the brain, +possesses an internal secretion, which, injected intravenously, causes a +marked rise of blood pressure and slowing of the heart beat. So far as I +know, this active principle of the gland has not been used in an attempt +to produce experimentally the lesions of arteriosclerosis. + +Wacker and Hueck succeeded in producing aortic disease in rabbits which +they considered to be in many points quite like human arteriosclerosis. +They injected the rabbits intravenously with cholesterin. They feel that +this is of great importance in view of the fact that exercise (muscle +metabolism) dyspnea, certain poisons, as well as adrenalin, and even +adrenal extirpation occasion a high cholesterin content of the blood. +Anitschow's experiments are confirmatory. He fed rabbits on large +amounts of cholesterin-containing substances (yolk of egg, brain +tissue) and pure cholesterin and found changes in the intima and inner +portion of the media consisting of fatty infiltration between the muscle +and elastic fibres, advent of small round cells and large phagocytic +cells containing fat droplets of cholesterin esters. The elastic fibres +were dissolved, broken up into fibrillae and these seemed to be absorbed. +The internal elastic lamina as such disappeared and the inner layer of +the aorta fused with the middle coat. He considers these changes to be +quite analogous to those found in human aortas. + +Oswald Loeb produced changes in the arteries of rabbits by feeding them +sodium lactate (lactic acid). His controls fed on other acids became +cachectic, but showed no arterial changes. He further found that in 100 +gm. of human blood there was normally from 15 to 30 mg. of lactic acid. +After heavy work, he found as much as 150 gm. He considers that after +adrenalin or nicotin injections, the function of the liver is so +disturbed that lactic acid is not bound. The arteriosclerosis is +actually due to the presence of free lactic acid in the circulation. He +succeeded, also, in producing lesions of the intima in a dog fed for a +long time on protein poor diet, plus lactic acid and sodium lactate. + +Another investigator, Steinbiss, fed rabbits on animal proteins only, a +diet totally foreign to their natural habits. He succeeded, however, in +keeping some alive for three months. He also tried various substances +and in the general conclusions says that no aortic changes could be +produced in animals kept in natural living conditions by any mechanical +means, increase of blood pressure, digital compression, hanging by hind +legs, etc. In infectious diseases, especially septic, widespread +sclerotic changes occurred in the aorta. A most suggestive conclusion in +this "the most important result of feeding rabbits with animal proteins +is, along with a constant glycosuria, disease of the aorta and +peripheral arteries which is identical with changes in the aorta +produced by injections of adrenalin. The degree of disease of the +circulatory system increases with the duration of the experiment." + +By a small addition of vegetable to the protein diet, the lives of the +animals were prolonged at will. With this modification of the +experiment, the findings in the vessel walls were noticeably altered. +The changes affected chiefly the intima, to less degree the media, and +histologically were very much like human intimal disease. + +I have been unable to produce the slightest arterial lesions in rabbits +by intravenous injections of lead. Frothingham had no success feeding +animals with lead. In a study of autopsy material from persons up to 40 +years, who died of infectious disease, he found changes in the arteries +of those who had succumbed to infection with the pus cocci or to very +severe infectious disease. These changes were, however, localized, and +were not like those of the general diffuse arteriosclerosis. + +Adler has recently reported experiments on dogs, to which he fed or +injected intravenously various substances supposed to induce +arteriosclerotic changes. He was unable to find any arterial lesions +comparable to human arteriosclerosis. + +The difficulty experienced by experimenters is not surprising when the +character of the changes is considered. Arteriosclerosis is not an acute +process. In its very nature, it is of months' or years' standing, the +specific changes are of slow growth, and more in the nature of +degeneration. It would seem that a very careful study of the histories +of those with arteriosclerosis and a final examination upon the actual +tissue might eventually give us data for the etiology. + +The most frequent site of disease in these experimental lesions is the +thoracic aorta, and it is there also that the most severe changes are +seen. While the toxic action is felt in the vessels all over the body, +the lesions are, as a rule, scattered and small. The thoracic aorta +stands the brunt of the high pressure, and this combined with the +poisonous action of the drug or drugs, results in the formation of a +fusiform aneurysmal dilatation which stops at the diaphragmatic opening. +The aortic opening in the diaphragm seems to act as a flood gate, +allowing only a certain amount of blood to flow through, and thus the +abdominal aorta is protected to a great extent from the deleterious +effects of increased pressure. Focal degenerative lesions are, however, +found in the abdominal aorta. + +Changes somewhat analogous to those found in the human aorta as the +result of intimal proliferations, are produced in animals by the toxins +of the typhoid bacillus and the Streptococcus pyogenes. Clinically, +Thayer and Brush have found that the arteries of those who have +recovered from an attack of typhoid fever are more palpable than the +arteries of average individuals of equal age who have never had the +disease. + +Experimentally, the changes caused by the toxins above noted are +proliferations of cells in the intima and subintimal tissues, and a +breaking up of the internal elastic laminae into several parallel layers +which stretch themselves among the proliferating cells. The diphtheria +toxin, on the contrary, produces a lesion more like that caused by +adrenalin. All pathologists are not agreed as to whether the +experimental lesions produced by blood pressure raising drugs are +similar to the arteriosclerotic changes in the arteries of man. + +Some of the work on rabbits has been discredited for the reason that +arteriosclerosis appears spontaneously in about fifteen per cent of all +laboratory rabbits. Furthermore, comparatively young rabbits have been +found with arteriosclerosis. O. Loeb, however, denies this. He has +examined in the course of eight years 483 healthy rabbits and never +found arterial changes. The spontaneous lesions can not be distinguished +histologically from those due to adrenalin. They differ macroscopically +in that the lesion is usually limited to a few foci near the origin of +the aorta. + +Lesions produced by the drugs enumerated above represent one type of +experimental arteriosclerosis. More interesting and important are the +experiments which seem to show that high tension alone is capable of +producing lesions in arteries which in all respects correspond to +Adami's strain hypertrophy and overstrain theory. It has been shown that +when a portion of vein is placed under conditions of high arterial +pressure, as in a transplantation of a portion of vein into a carotid +artery, the vein undergoes marked connective tissue hypertrophy which +includes all the coats. This is evidently strain hypertrophy. Again, it +has been demonstrated that by suspending a previously healthy rabbit by +the hind legs for three minutes daily over a period of three to four +months, there results hypertrophy of the heart with thinning and +dilatation of the arch and the upper part of the thoracic aorta. No +change was found in the abdominal aorta. The carotids, however, were +larger than normal and they showed typical intimal sclerosis with +connective tissue thickening. + +Neither I nor others have been able to confirm this experiment, so it is +very doubtful whether mechanical pressure alone can produce true +arteriosclerosis. Some evidence is adduced to bear on this point, +however, in the fact that sclerosis of the pulmonary artery follows +often upon mitral stenosis. Yet we do not know but that factors other +than pressure alone produce the arteriosclerotic change in such cases, +so we are forced back on our conclusion expressed above; viz., that +experiments on animals fail to sustain the purely mechanical origin of +arteriosclerosis. + +The changes in the intima constitute the effort on the part of nature to +repair a defect in the vessel wall which is to compensate for the +weakened media and the widened lumen. This applies only to true +arteriosclerosis, not to the condition produced experimentally by the +toxin of the typhoid bacillus, for example. + +When an artery loses its elasticity and begins to have connective tissue +deposited in its walls, the pressure of the blood stretches the vessel +which is now no longer capable of retracting when the pulse wave has +passed, and, in consequence, the artery is actually lengthened. This +necessarily causes a tortuosity of the vessel which can be easily seen +in such arteries as the temporals, brachials, radials, and other +arteries near the surface of the skin. + +The exact mechanism of increase of blood pressure is not satisfactorily +explained. The smaller arteries all over the body are supplied with +vasoconstrictor and vasodilator nerve fibers from the sympathetic +nervous system. Normally when an organ is actively functionating the +vessels are widely dilated and the flow of blood is rapid. Among the +many factors which influence blood pressure and blood supply must be +reckoned the psychic. + +We know that normally there is a certain resistance offered to the +propulsion of blood through the arteries by the contraction of the +heart. This tonus is essential to the maintenance of an equalized +circulation. The muscular arterioles throughout the body by their tonus +serve to keep up the normal blood pressure and to distribute the blood +evenly to the various organs. Contraction of a large area of arterioles +increases the blood pressure and, strangely enough, the arteries respond +to increased arterial pressure, not by dilatation, but by contraction. +It would appear that rise of blood pressure tends to throw increased +work upon the musculature of the arterioles. This may be sufficient only +to cause them to hypertrophy, but further strain may easily lead to +exhaustion and to dilatation. "As a result strain hypertrophy of the +intima shows itself with thickening, and it may also be of the +adventitia, resulting in chronic periarteritis. And now with continued +degeneration of the medial muscle in those muscular arteries, fibrosis +of the media may also show itself. I would thus regard muscular +hypertrophy of the arteries and fibrosis of the different coats as +different stages in one and the same process. Whether these peripheral +changes are the more marked, or the central, depends upon the relative +resisting power of the elastic and muscular arteries of the individual +respectively." (Adami.) + +[Illustration: Fig. 10.--Cross-section of a small artery in the +mesentery. Note that the vessel appears capable of being much widened. +The internal elastic lamina is thrown into folds somewhat resembling the +convolutions of the brain. Note also that the middle coat of the artery +is composed almost entirely of muscle. The enormous number of such +vessels in the mesentery and intestines explains the ability of the +splanchnic area to accommodate the greater part of the blood in the +body. Universal constriction of these vessels would naturally render the +intestines anemic. The vasomotor control of these vessels plays an +important role in the distribution of the blood. Small arteries in the +skin and in other organs, possibly the brain, have a similar function. +(Microphotograph, highly magnified.)] + +It is conceivable that in one section of the body the vessels may be +markedly contracted, but if there is dilatation in some other part there +will be no increased work on the part of the heart, and theoretically, +there should be no rise of blood pressure. The vascular system, however, +while likened to a system of rubber tubes, must be regarded as a very +live system, every subsystem having the property of separate control. + +For blood tension to be raised all over the body, conditions must favor +the generalized contraction of a large area of arterioles. Some authors +consider that the so-called viscosity of the blood also is a factor in +the causation of increased tension. The usual cause for the high tension +is probably the presence in the blood of some poisonous substance. + +It is held by some authors that the great splanchnic area is capable of +holding all the blood in the body and in respect of its liability to +arteriosclerosis, it is second only to the aorta and coronary arteries. +The enormous area of the skin vessels could probably contain most of the +blood. The tone of the vasoconstrictor center controls the distribution +of blood throughout the body. The fact that the vessels in the +splanchnic area are frequently attacked by sclerotic changes means, as a +rule, increase of work for the heart.[1] The resistance offered to the +passage of the blood must be great and signifies that, for blood to +travel at the same rate that it did before the resistance set in, more +power must be expended in its propulsion. In other words, the heart must +gradually become accustomed to the changed conditions, and, as a result +of increased work, the muscle hypertrophies. (See Fig. 11.) + + [1] Longcope and McClintock, however, conclude that permanent + constriction of the superior mesenteric artery and celiac axis, as well + as gradual occlusion of one or both of these vessels, may be present in + dogs for at least five months without giving rise to definite and + constant elevation of blood pressure or to hypertrophy of the heart. + Further, they have been unable to find at autopsy on man a definite + association between sclerosis of the abdominal aorta and great + splanchnic vessels and cardiac hypertrophy. + +[Illustration: Fig. 11.--Enormous hypertrophy of left ventricle probably +due to prolonged increased peripheral resistance. Note that the whole +anterior surface of the heart is occupied by the left ventricle. The +right ventricle does not appear to be much affected. x2/3.] + +In diffuse arteriosclerosis accompanied by chronic nephritis the heart +is always hypertrophied. This is a result, not a cause of the +condition. In the pure type, there is hypertrophy only of the left +ventricle without dilatation of the chamber. The muscle fibers are +increased in number and in size, and there are frequently areas of +fibrous myocarditis due to necrosis caused by insufficient nutrition of +parts of the muscle. In these cases the coronary arteries share in the +generalized arteriosclerotic process. The openings of the arteries +behind the semilunar valves may be very small. There is often thickening +and puckering of the aortic valves and of the anterior leaflet of the +mitral valve leading, at times, to actual insufficiency of the orifice. +Later, when the heart begins to weaken, there is dilatation of the +chambers and loud murmurs result, caused by the inability of the +nondistensible valves to close the dilated orifices. Until the +compensation is established, it is impossible to say whether or not true +insufficiency is present. + +In senile arteriosclerosis there is the physiologic atrophy of the media +to be reckoned with. This change has already been referred to. When such +degeneration has taken place, the normal blood pressure may be +sufficient to cause stretching of the already weakened media with or +without hypertrophy of the intima. The arteries may be so lined with +deposits of calcareous matter that they appear as pipe stems. More +frequently there are rings of calcified material placed closely together +or irregular beading, giving to the palpating finger the impression of +feeling a string of very fine beads. The arteries are often tortuous, +hard, and are absolutely nondistensible. At times no pulse wave can be +felt. + +The larger arteries such as the brachials and femorals are most +affected. The walls become thinned and show cracks, and areas +apparently, but not actually denuded of intima. Yellowish-white, +irregular, raised plaques are scattered here and there. Interspersed +among these areas are irregularly shaped clean-cut ulcers having as a +rule a smooth base, and frequently on the base is a thin plate of +calcified matter. The color of these denuded areas is usually brownish +red or reddish brown. White thrombi may be deposited on these areas. The +danger of an embolus plugging one of the smaller arteries is great and +probably happens more often than we think. The collateral circulation is +able to supply the thrombosed area. Should the thrombus be on the +carotid arteries, hemiplegia may result from cerebral embolism. On +microscopic examination of the arteries there is seen extreme +degeneration of all the coats, the degeneration of the media leading +almost to an obliteration of that coat. On seeing such arteries as these +one wonders how the circulation could have been maintained and the +organs nourished. Senile atrophy of the internal organs naturally goes +hand in hand with such arterial changes. + +There is, as a rule, no increase in arterial tension; on the contrary, +the pressure is apt to be low. This is readily understood when the heart +is seen. This organ is small, the muscle is much thinned, it is flabby +and of a brownish tint, the so-called "brown atrophy." Microscopically, +there is seen to be much fragmentation of the fibers with a marked +increase of the brown pigment granules which surround the cell nuclei. +Cases are seen, however, in which blood pressure increases as the +patient grows older. The hearts in such cases are more or less +hypertrophied and show extensive areas of fibroid myocarditis. + +From what has been said, it follows that hypertension alone may be the +cause of arteriosclerosis; that certain poisons in the blood which +attack the media and cause it to degenerate and weaken cause +arteriosclerosis without increased blood pressure; that the normal blood +pressure may be, for the artery which is physiologically weakened in an +individual over fifty, really hypertension, and arteriosclerosis may +result. Our observations lead us to believe that the process is at +bottom one and the same. The different types noted clinically depend +upon the nature of the etiologic factors and the kind of arterial tissue +with which the individual is endowed. This view at least brings some +order out of previous chaos, and corresponds well with our present +knowledge of the disease. + +There are many cases of arteriosclerosis which lead to definite +interference with the closure of the valves of the heart, particularly +the aortic and the mitral. It has been said that puckerings of the +valves frequently occur (Fig. 12). This arteriosclerotic endocarditis at +times leads to very definite heart lesions, chiefly aortic or mitral +insufficiency, or both with, at times, murmurs of a stenotic character +at the base. There is rarely true aortic stenosis, however. The murmur +is caused by the passage of the blood over the roughened valves and into +the dilated aorta. Aortic stenosis is one of the rarest of the valvular +lesions affecting the valves of the left heart, and should be diagnosed +only when all factors, including the typical pulse tracings, are taken +into consideration. + +[Illustration: Fig. 12.--Aortic incompetence with hypertrophy and +dilatation of left ventricle, the result of arteriosclerosis affecting +the aortic valves. Note how the valves have been curled, thickened, and +shortened, the edges of valves being a half inch below the upper points +of attachment. The anterior coronary artery is shown, the lumen +narrowed. (Reduced one-half.)] + +The kidneys, as a rule, show extensive sclerosis. They are small, firm, +and contracted and not always to be differentiated from the contracted +kidneys of chronic inflammation. The lesions of the arteriosclerotic +kidney are due to narrowing and eventual obstruction of the afferent +vessels. The organs are usually bright red or grayish red in color. At +times there is marked fatty degeneration of cortex and medulla, giving +to them a yellowish streaking. The capsule is here and there adherent, +the cortex is much thinned and irregular. The surface presents a +roughly granular appearance. The glomeruli stand out as whitish dots +and the sclerosed arteries are easily recognized, as their walls are +much thickened. The process does not, as a rule, affect the whole kidney +equally, but rather affects those portions corresponding to the +interlobular arteries. The replacement of the normal kidney tissue by +connective tissue and the resulting contraction of this latter tissue +leads to the formation of scars. As the process is not regular, the +scarring is deeper in some places than in others, with the result that +localized rather sharply depressed areas appear on the surface. The +pelvis is relatively large and is filled with fat. The renal artery is +often markedly sclerosed and the whole process may be due to localized +thickening of the artery, or as part of a general arteriosclerosis. The +latter is the more frequent. Microscopically, it is seen that the +tubules are atrophied, the Bowman's capsules are, as a rule, thickened, +and the glomeruli are shrunken or have been replaced by fibrous tissue. +In places they have fallen out of the section. There is marked +proliferation of connective tissue in cortex and medulla. The arterioles +are thickened, the sclerosis being either of the intima or media or of +both. There is even occlusion of many arterioles. + +Changes in other organs as the result of arteriosclerosis of their +afferent vessels occur, but are not so characteristic as in the kidney. +In the brain the result of gradual thickening of the arterioles is a +diminished blood supply, softening of the portion supplied by the +artery, and later a connective tissue deposit. The occurrence of thrombi +is favored and, now and again, a thrombus plugs an artery which supplies +an important and even vital part of the brain. The arteries of the brain +are end arteries, hence there is no chance for collateral circulation. +It is therefore evident how serious a result may follow the disturbance +in or actual deprivation of blood supply to any of the brain centers or +to the internal capsule. + + +=Arteriosclerosis of the Pulmonary Arteries= + +There have been a number of cases of sclerosis of the pulmonary +arteries, either alone, or associated with general systemic +arteriosclerosis. + +A primary and a secondary form are recognized, the former in conjunction +with congenital malformations of the heart, the latter as the result of +severe infection or of mitral stenosis. These two causes seem to be the +most important in the production of the arterial changes. The cases thus +far described have revealed widespread thickening of the pulmonary +arteries. If one may judge by the description of the pathologic changes, +the condition is quite similar to that produced in a vein by +transplantation along the course of an artery. The diffuse form with +connective tissue thickening of all coats has been generally described. +There is also obliterating endarteritis of the smaller vessels. In the +etiology of the condition severe infection seems to play a prominent +role. The constant presence of right ventricular hypertrophy is +interesting, the heart dullness extends, as a rule, far to the right of +the sternum. In some of the cases no demonstrable changes were observed +in the bronchial arteries or in the pulmonary veins. + +Sanders has described a case of primary pulmonary arteriosclerosis with +hypertrophy of the right ventricle. + +Recently Warthin[2] has reported a case of syphilitic sclerosis of the +pulmonary artery which places the lesion in exactly the same category as +that of syphilis in the systemic arteries. There was also aneurysm of +the left upper division present and, to settle the etiologic nature of +the process, Spirochete pallida were found in the wall of the aneurysm +sac and in that of the pulmonary artery. The microscopic picture in the +pulmonary artery could not be told from that in a syphilitic aorta. + + [2] Warthin, A. S.: Am. Jour. Syph., 1918, i, 693. + + +=Sclerosis of the Veins= + +Phlebosclerosis not infrequently occurs with arteriosclerosis. It is +seen in those cases characterized by high blood pressure. Such increased +pressure in the veins is due, for example, to cirrhosis of the liver +which affects the portal circulation, or to mitral stenosis which +affects the pulmonary veins. The affected vessels are usually dilated. +The intima shows compensatory thickening especially where the media is +thinned. As a rule all the coats are involved in the connective tissue +thickening. Occasionally hyaline degeneration or calcification of the +new-formed tissue is seen. "Without existing arteriosclerosis the +peripheral veins may be sclerotic usually in conditions of debility, but +not infrequently in young persons." (Osler.) + +In many cases of arteriosclerosis, the pathologic changes are not +confined to the arteries, but are found in the veins as well as in the +capillaries. Such cases could be called angiosclerosis. + + + + +CHAPTER III + +PHYSIOLOGY OF THE CIRCULATION + + +No attempt will be made to cover the entire subject of the physiology of +the circulation. Only in so far as it relates to arteriosclerosis and +blood pressure and has a bearing on the probable explanation of blood +pressure phenomena will it be discussed. + +"The heart and the blood vessels form a closed vascular system, +containing a certain amount of blood. This blood is kept in endless +circulation mainly by the force of the muscular contractions of the +heart; but the bed through which it flows varies greatly in width at +different parts of the circuit, and the resistance offered to the moving +blood is very much greater in the capillaries than in the large vessels. +It follows, from the irregularities in size of the channels through +which it flows, that the blood stream is not uniform in character +throughout the entire circuit--indeed, just the opposite is true. From +point to point in the branching system of vessels the blood varies in +regard to its velocity, its head of pressure, etc. These variations are +connected in part with the fixed structure of the system and in part are +dependent upon the changing properties of the living matter of which the +system is composed." (W. H. Howell.) + +If the vascular system were composed of a central pump, projecting at +every stroke a given amount of liquid into a series of rigid tubes, the +aggregate cross sections of which were equal to the cross section of the +main pipe, then the velocity at the openings would be the same as at the +source (making allowances for friction). The problem would then be a +simple one. In the circulation of the blood no such simple condition +obtains. The capillary beds is an enormous area through which the blood +flows slowly. From the time the blood is thrown into the aorta the +velocity begins to diminish until it reaches its minimum in the +capillaries. In no two persons is the initial velocity at the heart the +same, nor in the same person is it the same at all times of day. The +size of the heart, the actual strength of the muscle, the amount of +blood ejected at every beat, and the size and elasticity of the aorta +are some of the factors which determine the velocity of blood at the +aortic orifice. When to these factors are added the differences in +arterial tissue, the activity or resting stage of the various organs, +etc., the question becomes exceedingly complicated. In spite of these +many disturbing elements, attempts more or less successful have been +made to estimate the velocity of the blood in animals. Thus, in the +carotid of the horse the velocity was found to be 300 mm. per second +(Volkman) and 297 mm. (Chauveau); in the carotid of the dog, 260 mm. +(Vierordt). In the jugular vein of the dog Vierordt found the velocity +to be 225 mm. per second. These figures do not represent the actual +velocity of the blood in all horses or all dogs, but they do give us +some general idea of the rate of flow of the blood. For man it has been +calculated that the velocity in the aorta is about 320 mm. per second. +The velocity is not uniform in the large arteries, where at every heart +beat there is a sudden increase followed by a decrease as the heart goes +into diastole. The farther away from the heart the measurements are made +the more even is the flow. + +Observations by W. H. Luedde with the Zeiss binocular corneal microscope +on the rate of flow in the conjunctival capillaries must modify somewhat +our former conceptions. He finds that "The rate varies in the different +arteries, capillaries, and veins from a barely perceptible motion to a +little more than 1 mm. per second. Further, some parts of the capillary +network are ordinarily supplied with blood elements only occasionally. +This is shown by the passage of a column of corpuscles along a certain +line, followed after an interval of seconds, during which no corpuscles +pass, by another column in the same line as before." + +The vessels of the conjunctiva probably are quite like superficial +vessels in the skin and mucous membranes. Therefore, we must be free to +admit that the circulation in them is not absolutely steady. Luedde +found further that in syphilitics there were tortuosities, +irregularities, minute aneurysmal dilatations and even obliterations of +capillaries. Some of the changes occurred as early as one month after +infection. + +The rate in the capillaries of man is estimated to be between 0.5 mm. +and 0.9 mm. per second. As the blood is collected into the veins and the +bed becomes smaller, the velocity increases until at the heart it is +almost the same as in the aorta. That the velocity could not be exactly +the same is evident from the fact that the cross section of the veins, +which return the blood to the right auricle, is greater than is the +cross section of the aorta. + +The volume of the bed is subject to rapid and wide fluctuations, which +are dependent on many causes, both physiologic and pathologic. The call +of an actively functionating organ or group of organs causes a widening +of a more or less extensive area, and the velocity necessarily varies. +In states of great relaxation of the vessels there may be a capillary +pulse. In order to force blood at the same rate through dilated vessels +as through normal vessels, there must be more blood or there must be a +more rapid contraction of the central pump. What actually happens, as a +rule, is an increase in the rate of the heart beat. There are +conditions--such, for example, as aortic insufficiency--where actually +more blood is thrown into the circulation at every beat, so that the +rate is not changed. + +It has been calculated that the average amount of blood thrown into the +aorta at every systole of the heart is from 50 to 100 c.c. This is +forcibly ejected into a vessel already filled (apparently) with blood. +In order to accommodate this sudden accession of fluid, the aorta must +expand. The aortic valves close, and during diastole the blood is forced +through the vascular system by the forcible, steady contraction of the +highly elastic aorta. Other large vessels which branch from the aorta +also have a part in this steady propulsion of blood. From seventy to +eighty times a minute the aorta is normally forcibly expanded to +accommodate the charge of the ventricle. It is not difficult to +understand the great frequency of patches of sclerosis in the arch when +these facts are borne in mind. + +What relationship the viscosity of the blood has to the rate and volume +of flow is not fully understood. As yet there is not much known about +the subject, and no one has devised a satisfactory means of measuring +the viscosity. It is thought by some that an increased viscosity assists +in producing an increased amount of work for the heart. + + +=Blood Pressure= + +Blood pressure is the expression used for a series of phenomena +resulting from the action of the heart. As every heart beat is actual +work done by the heart in overcoming resistance to the outflow of blood, +this force is approximately measurable in a large artery such as the +brachial. It has been determined that the pressure in the brachial +artery is almost equal to the intraventricular pressure in the left +ventricle. In animals it is easy to attach manometers to the carotid +artery and to measure the blood pressure accurately. Formerly the method +consisted in attaching a tube and allowing the blood to rise in the +tube. The height to which the blood rose measured the maximum pressure. +This is a crude method and has been replaced by the U-tube of mercury +with connection made to the artery by saline or Ringer's solution. This +apparatus is familiar to all physiologists. + +In man the measurement is most conveniently made from the brachial +artery. There is some difference in the pressure in the femoral and the +brachial and some use both arteries. However, the difficulty of +adjusting instruments to the upper leg, the great force which must be +used to compress the femoral artery and the relative inaccessibility of +the leg as compared to the arm, make the leg an inconvenient part for +use in blood pressure determinations. It is not to be recommended. + +Blood pressure is a valuable aid in diagnosis and of material help in +many cases in prognosis, but it is not infallible neither can it be used +alone to diagnose a case. Blood pressure is only one of many links in a +chain of evidence leading to diagnosis. It has been badly used and much +abused. It has been condemned unjustly when it did not furnish _all_ the +evidence. It has been made a fetish and worshipped by both doctors and +patients. A sane conception of blood pressure must be widely +disseminated lest we find it being discarded altogether. + +Blood pressure consists of more than the estimation of the systolic +pressure. The blood pressure picture consists of (1) the systolic +pressure, (2) the diastolic pressure, (3) the pulse pressure which is +the difference between the systolic and diastolic pressure, (4) the +pulse rate. Expressed in the literature it should read thus: 120-80-40; +72. That tells the whole story in a brief, accurate form. This is +recommended in history reporting. It must be ever kept in mind that a +blood pressure reading represents the work of the heart at the _moment +when it was taken_. Within a few minutes the pressure may vary up or +down. There is no normal pressure as such, but an average pressure for +any group of people of the same age living under similar conditions. The +habit of speaking of any systolic figure as normal should be broken. A +pressure picture may be normal but a systolic reading, whatever it may +be, is not accurately designated as normal. This distinction is worth +insisting upon. + + +=Blood Pressure Instruments= + +There are several instruments which are in common use for the purpose of +recording blood pressure in man. + +Historically, the determination of blood pressure for man began with the +attempt of K. Vierordt in 1855 to measure the blood pressure by placing +weights on the radial pulse until this was obliterated. The first useful +instrument, however, was devised by Marcy in 1876. He placed the hand in +a closed vessel containing water connected by tubing with a bottle for +raising the pressure and by another tube with a tambour and lever for +recording the size of the pulse waves. He maintained that when pressure +on the hand was made, the point where oscillations of the lever ceased +was the maximal pressure, the point where the oscillations of the +recording lever was largest, was the minimal pressure. + +This pioneer work was practically forgotten for twenty-five years. It +was not until 1887 that V. Basch devised an instrument which was used to +some extent. This instrument recorded only maximum pressure. It +consisted of a small rubber bulb filled with water communicating with a +mercury manometer. The bulb was pressed on the radial artery until the +pulse below it was obliterated and the pressure then read off on the +column of mercury. V. Basch later substituted a spring manometer for the +mercury column. Potain modified the apparatus by using air in the bulb +with an aneroid barometer for recording the pressure. These instruments +are necessarily grossly inaccurate. Moreover, they do not record the +diastolic pressure. + +In 1896 and 1897 further attempts were made to record blood pressure by +the introduction of a flat rubber bag encased in some nonyielding +material, which was placed around the upper arm. Riva-Rocci used silk, +while Hill and Barnard used leather. The latter used a bulb or Davidson +syringe to force air into the cuff around the arm and palpated the +radial artery at the wrist, noting the point of return of the pulse +after compression of the upper arm, and reading the pressure on a column +of mercury in a tube. + +Except that the width of the cuff has been increased from 5 cm. to 12 +cm., this is the general principle upon which all the blood pressure +instruments now in use are based. Most of the apparatuses make use of a +column of mercury in a U-tube to record the millimeters of pressure. As +the mercury is depressed in one arm to the same extent as it is raised +in the other arm the scale where readings are made is .5 cm. and the +divisions represent 2 mm. of mercury but are actually 1 mm. apart. + +The cuff was made 12 cm. in diameter because it was shown (v. +Recklinghausen) that with narrow cuffs much pressure was dissipated in +squeezing the tissues. Janeway has shown that with the use of the 12 cm. +cuff accurate values are obtained independently of the amount of muscle +and fat around the brachial artery. In other words if an actual systolic +blood pressure of 140 mm. is present in two individuals, the one with a +thin arm, the other with a thick arm, the instrument will record these +pressures the same where a 12 cm. arm band is used. We need have no fear +of obtaining too high a reading when we are taking pressure in a stout +or very muscular individual. Janeway also was the first to call +attention to the fact that the diastolic or minimal pressure was at the +point where the greatest oscillation of the mercury took place. This is +difficult to estimate in many cases as the eye can not follow slight +changes in the oscillation when the pressure in the cuff is gradually +reduced. Practically this is the case in small pulses. + +The Riva-Rocci instrument was modified by Cook. (See Fig. 13.) He used a +glass bulb containing mercury into which a glass tube projected. The +bulb was connected by outlet and tubing to the cuff and syringe. The +glass tube was marked off in centimeters and millimeters and for +convenience was jointed half way in its length. The instrument could be +carried in a box of convenient size. This instrument is fragile and more +cumbersome, although lighter in weight, than others and is very little +used at present. + +[Illustration: Fig. 13.--Cook's modification of Riva-Rocci's blood +pressure instrument.] + +Stanton's instrument (Fig. 14) is practically Cook's made more rigid in +every way but without the jointed tube. The cuff has a leather casing, +the pressure bulb is of heavy rubber, the glass tube in which the +mercury rises is fixed against a piece of flat metal and there are +stopcocks in a metal chamber introduced between the bulb and mercury +with which to regulate the in- and out-flow of air. The pressure can be +gradually lowered conveniently without removing the pressure bulb. + +[Illustration: Fig. 14.--Stanton's sphygmomanometer.] + +The most accurate mercury manometer is that of Erlanger. (Fig. 15.) The +instrument is bulky and is not practicable for the physician in +practice. The principle is that used by Riva-Rocci. There is an extra +T-tube introduced between the manometer and air bulb connecting with a +rubber bulb in a glass chamber. The oscillations of this are +communicated to a Marey tambour and recorded on smoked paper revolving +on a drum. There is a complicated valve which enables the operator to +reduce the pressure with varying degrees of slowness. The mercury is +placed in a U-tube with a scale alongside it. The instrument is +expensive and not as easy to manipulate as its advocates would have us +believe. Hirschfelder has added to the usefulness (as well as to the +complexity) of the Erlanger instrument, by placing two recording +tambours for the simultaneous registering of the carotid and venous +pulses. In spite of its complexity and necessary bulkiness, very +valuable data are obtained concerning the auricular contractions. + +[Illustration: Fig. 15.--The Erlanger sphygmomanometer with the +Hirschfelder attachments by means of which simultaneous tracings can be +obtained from the brachial, carotid, and venous pulses.] + +One of the best of the mercury instruments is the Brown +sphygmomanometer. In this (Fig. 16) the mercury is in a closed, +all-glass tube so that it can not spill under any sort of manipulation. +It is in this sense "fool-proof." The cuff, however, is poorly +constructed. It is too short and there are strings to tie it around the +arm. I have found that this causes undue pressure in a narrow circle and +renders the reading inaccurate. In the clinic we use this mercury +instrument with a long cuff like that provided by the Tycos instrument. + +[Illustration: Fig. 16.--Desk model Baumanometer.] + +The Faught instrument (Fig. 17) is larger than the Brown, but is less +easily broken and is not too cumbersome to carry around. The +substitution of a metal air pump for the rubber makes the apparatus more +durable. + +[Illustration: Fig. 17.--The Faught blood pressure instrument. An +excellent instrument which is quite easily carried about and is not +easily broken.] + +The v. Recklinghausen instrument is not employed to any extent in this +country. It is both expensive and cumbersome, and has no advantages over +the other instruments. + +Several other instruments have been devised and new ones are constantly +being added to the already large list. With those employing mercury the +principle is the same. The aim is to make an instrument which is easily +carried, durable, and accurate. + +In all the mercury instruments the diameter of the tube is 2 mm. One +would suppose that there would be noticeable differences in the readings +of the different mercury instruments depending upon the amount of +mercury used in the tube. By actual weight there is from 35 to 45 gms. +of mercury in the several instruments. After many trials, no noticeable +differences in blood pressure readings can be made out between a column +weighing 35 gm. and one weighing 45 gm. + +There is, however, the inertia of the mercury to be overcome, friction +between the tube and the mercury, and vapor tension. The mercury is +therefore not as sensitive to rapid changes of pressure in the cuff as a +lighter fluid would be. The mercury must be clean and the tube dry so +that there is no more friction than what is inherent between the mercury +and glass. In making readings on a rapid pulse the oscillations of the +mercury column are apt to be irregular or to cease now and then, due to +the fact that the downward oscillation coincides with a pulse wave, or +an upward oscillation receives the impact of two pulse waves transmitted +through the cuff. Instruments have been devised to obviate this +difficulty, but they have not come into favor. They are usually too +complicated and at present can not be recommended. + +[Illustration: Fig. 18.--Rogers' "Tycos" dial sphygmomanometer.] + +An instrument devised by Dr. Rogers (the "Tycos") has met with +considerable popularity. (Fig. 18.) This is not an instrument which +operates with a spring and lever. The instrument is composed essentially +of two metal discs carefully ground and attached at their circumferences +to the metal casing below the dial. There is an air chamber between +these discs through the center of which air is forced by the syringe +bulb. When air is forced into the space between these two discs, they +are forced apart to a very slight extent, with the highest pressures +only 2-3 mm. of bulging occurs. From data gathered after extensive use +for five years these discs were not found to have sprung. A lever +attached to a cog which in turn is attached to the dial needle magnifies +to an enormous extent the slightest expansion of the discs. Every dial +is handmade and every division is actually determined by using a U. S. +government mercury manometer of standard type. No two dials therefore +are alike in the spacing of the divisions of the scale but every one is +calibrated as an individual instrument. There is no doubt in the +author's mind that for the general practitioner the instrument has some +advantages over the mercury instruments. It reveals the slightest +irregularity in force of the heart beat. The oscillation of the dial +needle is more accurately followed by the eye than is that of the column +of mercury. The needle passes directly over the divisions of the scale, +while with usual mercury instruments the scale is an appreciable +distance (sometimes .5 cm.) from the column of mercury at the side. +(Fig. 19.) The diastolic pressure is more easily read on the "Tycos." +It is where the maximum oscillation of the needle occurs as the pressure +is slowly released from the cuff. Although it does not appear that this +instrument, if properly made and standardized, could become inaccurate, +nevertheless it is advisable to check it every few months against a +known accurate mercury manometer instrument. + +[Illustration: Fig. 19.--Detail of the dial in the "Tycos" instrument.] + +[Illustration: Fig. 20.--Faught dial instrument.] + +[Illustration: Fig. 21.--Detail of the dial of the Faught instrument.] + +Another perfectly satisfactory dial instrument is the Faught (Figs. 20 +and 21). The general plan of this differs in some minor points from the +"Tycos." I have compared the two and have found no difference in the +readings. Both can be recommended. + +[Illustration: Fig. 22.--The Sanborn instrument.] + +One or two other cheaper dial instruments are on the market. The Sanborn +seems to be quite satisfactory. (Fig. 22.) It is cheaper than the other +dial instruments. There is this much to be said, no instrument using a +spring as resistance to measure pressure can be recommended. + + +=Technic= + +The same technic applies to all the mercury instruments. The patient +sits or lies down comfortably. The right or left arm is bared to the +shoulder, the cuff is then slipped over the hand to the upper arm. (See +Fig. 23.) At least an inch of bare arm should show between the lower end +of the cuff and the bend of the elbow. The rubber is adjusted so that +the actual pressure from the bag is against the inner side of the arm. +The straps are tightened, care being taken not to compress the veins. +The upper part of the cuff should fit more snugly than the lower part. +The part of the instrument carrying the mercury column is now placed on +a level surface; the two arms of the mercury in the tube must be even, +and at _0_ on the scale. With the fingers of one hand on the radial +pulse, the bag is compressed until the pulse is no longer felt. (See +Fig. 24.) One should raise the pressure from 10-12 mm. above this, and +close the stopcock between the bulb and the mercury tube. In a good +instrument the column should not fall. If it does there is a leak of air +in the system of tubing and arm bag. Now with the finger on the pulse, +or where the pulse was last felt, gradually allow air to escape by +turning the stopcock so that the column of mercury falls about 2 mm. +(one division on the scale) for every heart beat or two. One must not +allow the column of mercury to descend too slowly as it is +uncomfortable for the patient and introduces a psychic element of +annoyance which affects the blood pressure. On the other hand, the +pressure must not be released too rapidly, else one runs over the points +of systolic and diastolic pressure and the readings are grossly +inaccurate. It is impossible to say how rapidly the mercury must fall. +Every operator must find that out for himself by practice. The first +perceptible pulse wave felt beneath the palpating finger at the wrist, +represents on the scale the systolic pressure. This can be seen to +correspond to a sudden increase in the magnitude of the oscillation of +the mercury column. The systolic pressure, thus obtained, is from 5-10 +mm. lower than the real systolic pressure. The more sensitive the +palpating finger, the more nearly does the systolic pressure reading +approach that found by using such an instrument as Erlanger's, where the +first pulse wave is magnified by the lever of the tambour. + +[Illustration: Fig. 23.--Method of taking blood pressure with a patient +in sitting position.] + +[Illustration: Fig. 24.--Method of taking blood pressure with patient +lying down.] + +The pressure is now allowed to fall, until the palpating finger feels +the largest possible pulse wave, which is coincident with the greatest +oscillation of the mercury. This is the diastolic pressure. Beyond this +point there is no oscillation of the mercury column. The difference +between the two is the pulse pressure. Thus the pulse is felt after +compression at 120 on the scale, and the maximum oscillation occurs at +80. The systolic pressure is 120 mm., the diastolic is 80 mm., and the +pulse pressure is 40 mm. + +With the "Tycos" or Faught the arm band is snugly wound around the arm, +the bag next to the skin and the end tucked in, so that the whole band +will not loosen when air is forced into the bag. The cuff is blown up +until the pulse is no longer felt. One should raise the pressure not +more than 10 mm. above the point of obliteration of the pulse. The valve +is then carefully opened so that the needle gradually turns toward zero. +At the first return of the pulse wave felt at the wrist, the needle is +sure to give a sudden jump. This is the systolic pressure and is read +off on the scale. The needle is now carefully watched until it shows the +maximum oscillation. This is the diastolic pressure. The difference +between the two is, as above, the pulse pressure. + +In taking pressure one should take the average of several, three or +four. Moreover, one must not take consecutive readings too quickly and +one must be sure that between every two readings all the air is out of +the cuff and that the mercury or dial is at zero. _It has been +repeatedly shown that in a cyanosed arm the systolic pressure is raised +so that even slight cyanosis between readings must be carefully +avoided._ + +The only accurate method of determining both the systolic and diastolic +pressure, but especially the diastolic, is by the so-called auscultatory +method. (See Fig. 25.) The cuff is adjusted in the usual way and one +places the bell of a binaural stethoscope over the brachial artery from +one to two centimeters below the lower edge of the cuff.[3] Care must +be taken that the bell is not pressed too firmly against the arm and +that the edge of the bell nearest the cuff is not pressed more firmly +than the opposite end. For this purpose, one can not use the ordinary +Bowles stethoscope or any of the other much lauded stethoscopes, because +the surface of the bell is too large. The diameter of the bell must not +be more than twenty-five millimeters, twenty is still better. It is +advisable before beginning the observation to locate with the finger the +pulse in the brachial artery just above the elbow, so that the +stethoscope may be placed over the course of the artery. (Fig. 26.) The +first wave which comes through is heard as a click, and occurs at a +point on the manometer or dial scale from 5-10 mm. higher than can +usually be palpated at the radial artery. This is the true systolic +pressure. By keeping the bell of the stethoscope over the brachial +artery while the pressure is falling, one comes to a point when all +sound suddenly ceases. This is said to be the diastolic pressure. This +is incorrect as will be shown later. + + [3] A firm makes a stethoscope so that the bell is clamped on the arm + leaving both the operator's hands free. + +[Illustration: Fig. 25.--Observation by the auscultatory method and a +mercury instrument. One hand regulates the stop cock which releases air +gradually.] + +[Illustration: Fig. 26.--Observation by the auscultatory method and a +dial instrument. The right hand holds the bulb and regulates the air +valve.] + + +=Arterial Pressure= + +The arterial pressure in the large arteries undergoes extensive +fluctuations with every heart beat. The maximum pressure produced by the +systole of the left ventricle of the heart is known as the =maximum= or +=systolic pressure=. It practically equals the intraventricular +pressure. The minimum pressure in the artery, the pressure at the end of +diastole, is called the =diastolic pressure=. The difference between the +systolic and diastolic pressures is known as the =pulse pressure=. There +is yet another term known as the =mean pressure=. For convenience, this +may be said to be the arithmetical mean of the systolic and diastolic +pressures. Actually, however, this can not be the case, owing to the +form of the pulse wave, which is not a uniform rise and fall--the +upstroke being a straight line, but the downstroke being broken usually +by two notches. We do not make use of the mean pressure in recording +results. It is of experimental interest and needs only to be mentioned +here. + +[Illustration: Fig. 27.--Schema to illustrate the gradual decrease in +pressure from the heart to the vena cava: (a), arteries; (c), +capillaries; (v), veins; (A), aorta, pressure 150 mm.; (B), brachial +artery, pressure 130 mm.; (F), femoral vein, 20 mm.; (IVC), inferior +vena cava, 3 mm. (Modified from Howell.)] + +It has been shown that the mean pressure is quite constant throughout +the whole arterial system. The maximum pressure necessarily falls as the +periphery of the vascular system is approached. In general it may be +said that the minimal pressure is quite constant. Too little attention +is paid to minimal and pulse pressure. The minimal pressure is +important, for it gives us valuable data as to the actual propulsive +force driving the blood forward to the periphery at the end of diastole. + +It is readily understood how the maximum pressure falls as the periphery +is approached, until in the arterioles the maximum and minimum pressures +are about equal. The pressure then in these arterioles is practically +the same as the diastolic pressure. Actually it is a few millimeters +less. The diastolic blood pressure would, therefore, measure the +peripheral resistance and, as the maximum for systolic pressure +represents approximately the intraventricular pressure, the difference +between the two, the pulse pressure, actually represents the force which +is driving the blood onward from the heart to the periphery. It is hence +very evident that the mere estimation of the systolic pressure gives us +but a portion of the information we are seeking. + +The pulse pressure is subject to wide fluctuations but as a rule for any +one normal heart it remains fairly constant as the rate varies. In a +rapidly beating heart the diastole is short and the diastolic pressure +rises. If the systolic pressure does not also rise, as in a normal heart +following exercise, we will say, the pulse pressure falls. We know that +when the pulse rate is constant, vasodilatation causes a fall in +diastolic pressure and a rise in pulse pressure. On the contrary, +vasoconstriction causes a rise in diastolic pressure and a fall in pulse +pressure. + +It is very probably the case that with two individuals of equal age and +equal pulse rate, and equal systolic pressure of 160 mm., the one with a +diastolic pressure of 110 mm. and, therefore, a pulse pressure of 50 mm. +is much worse off than the other with a diastolic pressure of 90 mm. and +a pulse pressure of 70 mm. The latter may be normal for the age of the +person especially when certain forms of fibrous arteriosclerosis +accompanied by enlarged heart are present. + +The former is not normal for any age. Low pulse pressure usually means a +weak vasomotor control and is only found in failing circulation or in +markedly run down states, such as after serious illness or in +tuberculosis. Therefore, it is most important to estimate accurately the +diastolic pressure as well as the systolic pressure, for only in this +way can we obtain any data of value regarding the driving power of the +heart and the condition of the vasomotor system. A high systolic +pressure does not necessarily mean that a great deal of blood is forced +into the capillaries. Actually it may mean that very little blood enters +the periphery. The heart wastes its strength in dilating constricted +vessels without actually carrying on the circulation adequately. + + +=Normal Pressure Variations= + +The systolic pressure varies considerably under conditions which are by +no means abnormal. Thus, the average for men at all ages is about 127 +mm. Hg. (All measurements are taken from the brachial artery, with the +individuals in the sitting posture.) For women the average is somewhat +lower, 120 mm. Hg. The pressure is lowest in children. In children from +6-12 years the average systolic pressure is 112 mm. Normally, there is a +gradual increase as age comes on, due, as will be shown in the +succeeding chapter, to physiologic changes which take place in the +arteries from birth to old age. In the chart here appended is +graphically shown the normal variations in the blood pressure at +different ages compiled from observations made on one thousand +presumably normal persons. (Fig. 28.) + +[Illustration: Fig. 28.--Chart showing the normal limits of variation in +systolic blood pressure. (After Woley.)] + +The diastolic pressure has been estimated to be about 35 to 45 mm. Hg +lower than the systolic pressure, and consequently these figures +represent the pulse pressure in the brachial artery of man. This is +equivalent to saying that every systole of the left ventricle distends +this artery by a sudden increase in pressure equal to the weight of a +column of mercury 2 mm. in diameter and 35 to 45 mm. high. Naturally, at +the heart the pressure is highest. As the blood goes toward the +capillary area the pressure gradually decreases until, at the openings +of the great veins into the heart, the pressure is least. At the aorta +(A) the pressure (systolic) is approximately 150 mm. Hg, at the brachial +artery (B) it is 130 mm., in the capillary system (C) it is 30 mm., in +the femoral vein (F) it is 20 mm., at the opening of the inferior vena +cava (I) it is 3 mm. + +Attention has been called to the normal systolic pressure at different +ages. This is not the only cause for variations in the blood pressure. +Normally, it is greater when in the erect position than when seated, +and greater when seated than when lying down. During the day there are +well-recognized changes. The pressure is lowest during the early morning +hours, when the person is asleep. In women there are variations due to +menstruation. Muscular exercise raises the blood pressure markedly. The +effect of a full meal is to raise the blood pressure. The explanation is +that during and following a meal there is dilatation of the abdominal +vessels. This takes blood from other parts of the body, provided that +the other factors in the circulation remain constant. A fall of +pressure would necessarily occur in the aorta. To compensate for this, +there is increased work on the part of the heart, which reveals itself +as increased pressure and pulse pressure. It is well known that the +interest in the process taken by an individual upon whom the blood +pressure is estimated for the first time tends to increase the rate of +the heart and to raise the blood pressure. For this reason the first few +readings on the instrument must be discarded, and not until the patient +looks upon the procedure calmly can the true blood pressure be obtained. +As a corollary to this statement, mental excitement, of whatever kind, +has a marked influence on the pressure. The patient must remain +absolutely quiet. Raising the head or the free arm causes the pressure +to rise. Another important physiologic variation is produced by +concentrated mental activity. This tends to hurry the heart and increase +the force of the beat. In short, it may be stated as a general rule that +any active functioning of a part of the body which naturally requires a +great excess of blood tends to elevate the blood pressure. At rest the +pressure is constant. Variations caused by the factors mentioned act +only transitorily, and the pressure shortly returns to normal. + + +=The Auscultatory Blood Pressure Phenomenon= + +Since the first description of the auscultatory blood pressure sounds by +Korotkov in 1905, this method has been more and more employed until +today it is the standard, recognized method of determining the points in +the blood pressure reading. When one applies the 12 cm. arm band over +the brachial artery and listens with the bell of the stethoscope about +one cm. below the cuff directly over the brachial artery near the bend +of the elbow, one hears an interesting series of sounds when the air in +the cuff is gradually reduced. The cuff is blown up above the maximum +pressure. As the air pressure around the arm gradually is lowered, the +series of sounds begins with a rather low-pitched, clear, clicking +sound. This is the first phase. This only lasts through a few +millimeters fall when a murmur is added and the tone becomes louder. +This click and murmur phase is the second phase. A few millimeters more +of drop in pressure and a clear, sharp, loud tone is audible. Usually +this tone lasts through a greater drop than any of the other tones. This +is the third phase. Rather suddenly the loud, clear tone gives place to +a dull muffled tone. In general the transition is quite sharp and +distinct. This is the fourth phase. The tone gradually or quickly ceases +until no tone is heard. This is the fifth phase (Ettinger.) + +The first phase is due to the sudden expansion of the collapsed portion +of the artery below the cuff and to the rapidity of the blood flow. This +causes the first sharp clicking sound which measures the systolic +pressure. + +The second, or murmur and sound phase, is due to the whorls in the blood +stream as the pressure is further released and the part of the artery +below the cuff begins to fill with blood. + +The third tone phase is due to the greater expansion of the artery and +to the lowered velocity in the artery. A loud tone may be produced by a +stiff artery and a slow stream or by an elastic artery and a rapid +stream. This tone is clear cut and in general is louder than the first +phase. + +The fourth phase is a transition from the third and becomes duller in +sound as the artery approaches the normal size. + +The fifth phase, no sound phase, occurs when the pressure in the cuff +exerts no compression on the artery and the vessel is full throughout +its length. + +It is generally conceded that the sounds heard are produced in the +artery itself and not at the heart. + +The tones vary greatly in different hearts. A very strong third tone +phase or prolongation of this phase usually means that the heart which +produces the tone is a strongly acting one, although allowances must be +made for a sclerosed artery in which there is a tendency to the +production of a sharp third phase. + +Weakness of the third phase, as a rule, indicates weakness of the heart +and this dulling of the third phase may be so excessive that no sound is +produced. Goodman and Howell have carried this method further by +measuring the individual phases and calculating the percentage of each +phase to the pulse pressure. Thus, if in a normal individual the +systolic pressure is 130 mm., the diastolic 85 mm., and the pulse +pressure 45 mm., the first phase lasts from 130 to 116 or 14 mm., the +second from 116 to 96, or 20 mm., the third from 96 to 91 or 5 mm., the +fourth from 91 to 85, or 6 mm. The first phase would then be 31.1 per +cent of the total pulse pressure, the second phase 44.4 per cent, the +third phase 11.1 per cent, and the fourth phase 13.3 per cent. They +consider that the second and third phases represent cardiac strength (C. +S.) and the first and fourth represent cardiac weakness (C. W.). They +believe that C. S. should normally be greater than C. W. In the example +above C. S.:C. W. = 55.5:44.4. In weak hearts, especially in +uncompensated hearts, the conditions are reversed and C. W. > C. S. This +is often the case. As a heart improves C. S. again tends to become +greater than C. W. They think that the phases should be studied in +respect to the sounds and also to the encroachment of one sound upon +another. + +These observations are interesting but we have not found the division +into phases as helpful as it was thought to be. We spent a great deal of +time on this question. All that can be said, in my opinion, is that a +loud, long third phase is usually evidence of cardiac strength. + +A further interesting feature which can be heard in all irregular hearts +is a great difference in intensity of the individual sounds. Goodman and +Howell call this phenomenon tonal arrhythmia. Irregularities can be made +out by the auscultatory method which can not be heard at the heart. + +In anemia the sounds are very loud and clear and do not seem to +represent the actual strength of the heart. + +The general lack of vasomotor tone in the blood vessels together with +some atrophy and flabbiness of the coats probably explains the loud +sounds. + +In polycythemia the sounds have a curious, dull, sticky character and +can not be differentiated accurately into phases, a condition which was +predicted from the knowledge of the sharp sounds in anemia. + +In not all cases can all phases be made out. It is usually the fourth +phase which fails to be heard. + +In such cases the loud third tone almost immediately passes to the fifth +phase or no sound phase. The importance of this will later be taken up. + +"In arteriosclerosis, with hardening and loss of elasticity of the +vessel walls, the auscultatory phenomena, according to Krylow, are apt +to be more pronounced, since the back pressure at the cuff probably +causes some dilatation of the vessel above it, while the lumen of the +vessel is smaller than normal. Both of these factors cause an increased +rapidity in the transmission of the blood wave when pressure in the cuff +is released, which in time favors the vibration of the vessel walls. + +"In high grade thickening of the arterial walls, however, especially +where calcification had occurred, Fischer found that the sounds were +distinctly less loud than normal, the more so in the arm, which showed +the greater degree of hardening. According to Ettinger's experience, the +rapidity of the flow distinctly increases the auscultatory phenomenon." +(Gittings.) + +The sounds depend upon the resonating character of the cuff, upon the +size and accessibility of the vessel, upon the force of the heart beat, +and upon the velocity of the blood. + + +=The Maximum and Minimum Pressures= + +The maximum (systolic) pressure is read at the point where the first +audible click is heard after the cuff is blown up and the pressure +gradually reduced by means of the needle valve in the hand bulb or on +the upright of the glass containing the mercury. All are agreed upon +this point. There has been some dispute as to the place where the +diastolic pressure should be read. Korotkov considered that the +diastolic pressure should be read at the fourth phase when the loud tone +suddenly becomes dulled. Others held that the diastolic pressure should +be read at the fifth phase, the absence of all sound. Experiments +carried out to determine this point were made by me with the assistance +of Prof. Eyster and Dr. Meek at the Physiological Laboratory of the +University of Wisconsin. We arranged apparatus making it possible to +hold the pressure in the carotid artery of dogs at maximum or minimum. A +femoral artery was then dissected and an instrument devised to compress +the artery with a water jacket. The whole was connected up with a +kymograph. A time marker was put in so as to record the place where +changes in sound were heard while listening below the cuff around the +femoral artery. Two sets of records were taken. One with pressure +greater than minimum pressure and a falling pressure over the femoral +artery (Fig. 29), the other with pressure at zero and gradually raised +to minimum pressure (Fig. 30). Both sets of records showed the same +result; viz., that at a point corresponding to the sudden change of tone +the pressure on the artery corresponded to the minimum pressure. It was +therefore concluded that experimentally in dogs the point where +diastolic pressure should be read is at the tone change from clear to +dull, not at the point where all sound disappears. + +[Illustration: Fig. 29.--Tracing of auscultatory phenomena. (See +explanation in legend of Fig. 30.)] + +[Illustration: Fig. 30.--Figures are to be read from left to right. The +top line records the points where sounds were heard, the figures above +the short vertical lines refer to tones (see text). Mx. B. P., maximum +blood-pressure. M. B. P., minimum blood-pressure. P. B., pressure bulb +recorder. It was impossible to lower and raise this bulb by hand without +obtaining the great irregular oscillations of the attached lever above +the mercury manometer. B. L., base line.] + +Erlanger showed some years ago, that with his instrument, the point at +which diastolic pressure should be read was at the instant when the +maximum oscillation of the lever suddenly became smaller. While +checking up the graphic with the auscultatory method using Erlanger's +instrument, it was noticed that the disappearance of all sound did not +correspond with the sudden diminution of the oscillation of the lever +connected with the brachial artery. A series of records were carefully +made on patients. It was seen that during the period of the third tone +phase the oscillations of the lever on the drum reached a maximum (Fig. +31) and remained at approximately the same height for some millimeters +while the pressure was gradually falling. At a point at which the third +tone, clear and distinct, became dull, there was an appreciable decrease +in the height of the pulse wave. From this point to the disappearance of +all sound there was a gradual diminution of the size of the pulse +waves. + +[Illustration: Fig. 31.--Fast drum. Sudden decrease in size of pulse +wave at 4, marking the change from clear sharp tone to dull tone.] + +[Illustration: Fig. 32.--Slow drum. Sudden decrease in amplitude at 4.] + +For normal pressures the difference between the fourth (dull) tone and +the fifth (disappearance of all tone) phase, amounted to 4 to 10 mm. +Occasionally the difference was so little, the change from sharp third +tone through fourth dull tone to disappearance of all sound was so +abrupt, that one could take the disappearance of all sound as the +diastolic pressure, with an error of not more than 2 to 4 mm. This is +within the limits of normal error and practically may be used by those +who have difficulty in noting the change from third to fourth phase. For +high pressures, however, the difference between fourth and fifth phases +was never less than 8 mm., and was found as much as 16 mm. The +diastolic, therefore, should always be taken at the fourth phase if +possible. + +It was found that with the dial instrument the greatest fling of the +lever corresponded to the third phase and the sudden lessened amplitude +of the oscillation was at the fourth phase and was coincident with the +change of tone from sharp to dull. Thus the diastolic pressure may be +read off on the dial scale by watching the fling of the hand and with +some practice one might acquire considerable accuracy. It is better, +simpler, and, for most observers, more accurate to use the stethoscope +and hear the change of sound. + + +=The Relative Importance of the Systolic and Diastolic Pressures= + +The systolic pressure represents the maximum force of the heart. It is +measured by noting the first sound audible over the brachial artery +using the auscultatory method. It is the summation of two factors +largely; the force expended in opening the aortic valves (potential) and +the force expended from that point to the end of systole, the force +which is actually driving the blood to the periphery (kinetic). To start +the blood in motion, the heart must overcome a dead weight equal to the +sum of all the forces holding the aortic valves closed. This sum of +factors, called the peripheral resistance, must be reached and passed by +the force of the ventricular beat before one drop of blood is set in +motion along the aorta. This factor of resistance assumes a great +importance. + +The systolic pressure is always fluctuating as it depends upon so many +conditions, and the calls of the body except during sleep are many and +various. In a study of diurnal variations in arterial blood pressure it +has been found that--(1) A rise of maximum pressure averaging 8 mm. of +Hg. occurs immediately on the ingestion of food. A gradual fall then +takes place until the beginning of the next meal. There is also a slight +general rise of the maximum pressure during the day. (2) The range of +maximum pressure varies considerably in different individuals, but the +highest and lowest maximum pressures are practically equidistant from +the average pressure of any one individual.[4] + + [4] Weyse, A. W., and Lutz, B. R.: Diurnal Variations in Arterial + Blood Pressure, Am. Jour. Physiol., 1915, xxxvii, 330. + +The pressure is lowest during sleep and gradually rises near the end of +sleep, so that on awakening the pressure was the same as before sleep. + +Physiologically there are many conditions which modify the systolic +pressure. Sleep, position, meals, exercise, emotional states cause often +wide fluctuations which may be very sudden. It should be constantly +borne in mind, that the systolic pressure reading which is made, is the +maximum effort of the heart at that moment only. + +The diastolic pressure measures the peripheral resistance. It measures +the work of the heart, the potential energy, up to the moment of the +opening of the aortic valves. It is the actual pressure in the aorta. +The diastolic pressure is not very variable; it is not subject to the +same influences which disturb the systolic pressure. It fluctuates as a +rule, within a small range. It is not affected by diet, by mental +excitement, by subconscious psychic influences, to anything like the +extent to which the systolic pressure is affected by the action of +these factors. The diastolic pressure is determined by the tone in the +arterioles and is under the control of the vasomotor sympathetic system. +Any agent which causes chronic irritation of the whole vasomotor system +produces increase in the peripheral resistance with consequent rise in +the diastolic pressure. Any agent which acts to produce thickening of +the walls of the arterioles, narrowing their lumina, produces the same +effect. + +Such states naturally result in increased work on the part of the heart, +which as a result, hypertrophies in the left ventricle. The increase in +size and strength is a compensatory process in order to keep the tissues +supplied with their requisite quota of blood. Conversely, paralysis of +the vasomotor system produces fall of diastolic pressure which, if long +continued, results in death. + +The diastolic pressure then is of importance for the following reasons: + +1. It measures peripheral resistance. + +2. It is the measure of the tonus of the vasomotor system. + +3. It is one of the points to determine pulse pressure. + +4. Pulse pressure measures the actual driving force, the kinetic energy +of the heart. + +5. It enables us to judge of the volume output, for pulse pressure which +is only determined by measuring both systolic and diastolic pressure, is +such an index. + +6. It is more stable than the systolic pressure, subject to fewer more +or less unknown influences. + +7. It is increased by exercise. + +8. It is increased by conditions which increase peripheral resistance. + +9. The gradual increase of diastolic pressure means harder work for the +heart to supply the parts of the body with blood. + +10. Increased diastolic pressure is always accompanied by increased +pulse pressure, and increased size of the left ventricle, temporarily +(exercise) or permanently. + +11. Decreased diastolic pressure goes hand in hand with vasomotor +relaxation, as in fevers, etc. + +12. Low diastolic pressure is frequently pathognomonic of aortic +insufficiency. + +13. When the systolic and diastolic pressures approach, heart failure is +imminent either when pressure picture is high or low. + +When all these factors are taken into consideration, it becomes apparent +that the diastolic pressure is most important, if not the most important +part of the pressure picture. + +Up to within a very brief time all the statistical evidence of blood +pressure was based on systolic readings alone. This data is most +valuable and much has been learned as to diagnosis and prognosis, but it +is a mass of data based on a one-sided picture and can not be as +valuable as the statistics which will undoubtedly be published later +when all the pressure picture figures can be analyzed. + + +=Pulse Pressure= + +The pulse pressure is the actual head of pressure which is forcing the +blood to the periphery. At every systole a certain amount of blood 75-90 +c.c. (Howell) is thrown violently into an already comfortably filled +aorta. The sudden ejection of this blood instigates a wave which rapidly +passes down the arteries as the pulse wave. The elastic recoil of the +aorta and large arteries near the heart contract upon the blood and keep +it moving during diastole. Normally the blood-vessels are highly elastic +tubes with an almost perfect coefficient of elasticity. The pulse +pressure varies under normal conditions from 30 to 50 mm. Hg. There is a +very definite relationship between the velocity of blood and the pulse +pressure which is expressed thus; velocity = pulse rate x pulse +pressure.[5] + +Further it has been demonstrated that under normal conditions and during +various procedures--the pulse pressure is a reliable index of the +systolic output.[6] + + [5] Erlanger and Hooker: An Experimental Study of Blood Pressure and + of Pulse Pressure in Man, Johns Hopkins Hosp. Rep., 1904, xii, 145. + + [6] Dawson and Gorham: The Pulse Pressure as an Index of Systolic + Output, Jour. Exper. Med., 1908, x, 484. + +Increased pulse pressure therefore goes hand in hand with greater +systolic output. Physiologically this is most ideally seen during +exercise. Following exercise the pulse rate increases, the systolic +pressure rises greatly, the diastolic slightly or not at all. The pulse +pressure therefore is increased. The velocity also is much increased. +The call comes for more blood and the heart responds. In the chronic +high pulse pressures there are four correlated conditions which, so far +as I have studied them, are always present. These are: (1) An increase +in size of the cavity of the left ventricle. The ventricle actually by +measurement contains more blood than normal, and therefore throws out +more blood at every systole. The volume output is greater per unit of +time. (2) There is actual permanent increase in diameter of the arch of +the aorta. This is a compensating process to accommodate the increased +charge from the left ventricle. (3) There are on careful auscultation +over the manubrium, particularly the lower half, breath sounds which +vary from bronchial to intensely tubular, depending upon the anatomic +placing of the aorta, the shape of the chest, and the degree of +dilatation. Often there is very slight impairment of the percussion note +as well. (4) There is increase in size of all the large distributing +arteries, carotids, brachials, femorals, renals, celiac axis, etc., with +fibrous changes in the media, loss of some elasticity, and increase in +size of the pulse wave. Increased pulse pressure means increased volume +output, but does not always mean increased velocity. The proper +distribution of blood to the various organs of the body is regulated by +the vasomotor system acting upon the small arteries which contain +considerable unstriated muscle. When fibrous arteriosclerosis is present +there is loss of elasticity in the distributing arteries and a greater +volume of blood must be thrown out by the ventricle at every systole in +order that every organ shall have its full quota of blood. A force which +is sufficient to send blood through elastic normal distributing tubes +becomes totally insufficient to send the same amount of blood through +tortuous and more or less inelastic tubes. + +It is evident then that pulse pressure is exceedingly important. It can +only be determined by measuring both the _systolic_ and _diastolic_ +pressure. The pulse rate must also be known in order to compute the +velocity. It is essential to have the whole pressure picture for all +cases if correct conclusions are to be drawn. + +In an irregular heart, especially in the cases due to myocardial +disease, it is quite impossible to determine the true diastolic +pressure. One can only approximate it and say that the pulse pressure is +low or high. As a matter of fact the real systolic pressure can not be +determined. For this figure the place on the scale where most of the +beats are heard may be taken for the average systolic pressure. No one +can seriously maintain that he can measure the diastolic pressure under +all circumstances. + +By means of the auscultatory method of measuring blood pressure we are +able to determine irregularities of force in the heart beats more easily +than by listening to the heart sounds. A pulsus alternans is readily +made out. The irregular tones heard over the brachial artery in cases of +irregular heart action have been called "tonal arrhythmias." + + +=Blood Pressure Variations= + +A recent study of diurnal variations in blood pressure has shown that +while the maximum pressure rises after the ingestion of food and +steadily rises slightly throughout the day, the minimum blood pressure +is very uniform throughout the day, and is little affected by the +ingestion and digestion of meals. When it is affected, a rise or a fall +may take place. Throughout the day, it tends to become slightly lower. +The pulse pressure then is greater towards evening. + +Weysse and Lutz in a study of this question draw the following +conclusions: + +1. A rise of maximum pressure averaging 8 mm. of Hg occurs immediately +on the ingestion of food. A gradual fall then takes place until the +beginning of the next meal. There is also a slight general rise of the +maximum pressure during the day. + +2. The average maximum blood pressure for healthy young men in the +neighborhood of 20 years of age is 120 mm. of Hg. This pressure obtains +commonly one hour after meals. The higher maximum pressures occur +immediately after meals, and the lower, as a rule, immediately before +meals. + +3. The range of maximum pressure varies considerably in different +individuals, but the highest and lowest maximum pressures are +practically equidistant from the average pressure of any one individual. + +4. The minimum blood pressure is very uniform throughout the day, and is +little affected by the ingestion and digestion of meals. When it is +affected a rise or fall may take place. There is a tendency for a slight +general lowering of the minimum pressure throughout the day. + +5. The average minimum blood pressure for healthy young men in the +neighborhood of 20 years of age is 85 mm. of Hg. Thus we get an average +pulse pressure of 35 mm. of Hg. + +6. Pulse pressure, pulse rate, and the relative velocity of the blood +flow are increased immediately upon the ingestion of meals. They attain +the maximum, as a rule, in half an hour, and then decline slowly until +the next meal. There is a general increase in each throughout the day. + +These measurements were made upon persons at rest. Almost any form of +exercise would have made the variations much greater. No account is +taken of the psychic variations which for the physician are the most +important to bear in mind. Neglect to take this variation into account +will inevitably lead to false conclusions. + +THE AVERAGE DIURNAL BLOOD PRESSURE RECORD OF THE TEN SUBJECTS + +==========+=======+=======+=======+=======+========+=======+=============== + TIME |MAXIMUM|MINIMUM| MEAN | PULSE | PULSE |PP x PR| NOTES + | | | | |PRESSURE| RATE | +----------+-------+-------+-------+-------+--------+-------+--------------- + |_mm._Hg|_mm._Hg|_mm._Hg|_mm._Hg| | | +4:30 p.m. | 119.5 | 84.1 | 101.8 | 35.4 | 72.0 | 2549 | +5:00 p.m. | 117.7 | 83.5 | 100.6 | 34.2 | 71.1 | 2432 | +6:00 p.m. | 118.0 | 84.0 | 101.0 | 34.0 | 74.9 | 2547 |Before dinner +6:45 p.m. | 127.2 | 88.2 | 107.7 | 39.0 | 78.1 | 3046 |After dinner +7:00 p.m. | 124.7 | 87.7 | 106.2 | 37.0 | 76.0 | 2812 | +7:30 p.m. | 122.0 | 83.4 | 102.7 | 38.6 | 76.0 | 2934 | +8:00 p.m. | 122.4 | 85.5 | 103.4 | 36.9 | 71.2 | 2527 | +8:30 p.m. | 120.0 | 85.0 | 102.5 | 35.0 | 69.7 | 2439 | +9:00 p.m. | 120.5 | 84.7 | 102.5 | 35.8 | 65.2 | 2334 | +9:30 p.m. | 118.2 | 84.4 | 101.6 | 33.8 | 64.4 | 2177 | +7:30 a.m. | 118.4 | 87.6 | 103.0 | 30.8 | 70.3 | 2165 | +8:00 a.m. | 116.4 | 86.4 | 101.4 | 30.0 | 69.8 | 2094 Before breakfast +8:30 a.m. | 124.2 | 85.4 | 104.8 | 38.8 | 79.4 | 3081 |After breakfast +9:00 a.m. | 123.8 | 84.4 | 104.1 | 39.4 | 84.1 | 3313 | +10:00 a.m.| 118.2 | 83.6 | 100.9 | 34.6 | 70.7 | 2446 | +11:00 a.m.| 116.2 | 84.8 | 100.5 | 31.4 | 67.7 | 2126 | +12:00 m | 114.4 | 83.2 | 98.8 | 31.2 | 66.2 | 2065 |Before luncheon +12:30 p.m.| 122.8 | 83.2 | 103.0 | 39.6 | 70.9 | 2808 |After luncheon +1:00 p.m. | 122.3 | 82.0 | 102.1 | 40.3 | 79.7 | 3212 | +2:00 p.m. | 118.4 | 81.4 | 99.9 | 37.0 | 77.6 | 2871 | +3:00 p.m. | 118.8 | 82.6 | 100.7 | 36.2 | 75.1 | 2719 | +4:00 p.m. | 115.8 | 82.0 | 98.9 | 33.8 | 71.9 | 2420 | +5:00 p.m. | 117.2 | 83.4 | 100.3 | 33.8 | 69.6 | 2352 | +6:00 p.m. | 117.4 | 84.4 | 100.9 | 33.0 | 72.8 | 2402 |Before dinner +6:45 p.m. | 124.6 | 83.1 | 103.8 | 41.5 | 80.4 | 3337 |After dinner +7:00 p.m. | 125.2 | 84.2 | 104.7 | 41.0 | 76.1 | 3120 | +7:30 p.m. | 122.0 | 84.0 | 103.0 | 38.0 | 73.7 | 2801 | +8:00 p.m. | 119.6 | 85.0 | 102.3 | 34.6 | 72.3 | 2502 | +8:30 p.m. | 119.7 | 84.0 | 101.3 | 34.7 | 69.0 | 2394 | +9:00 p.m. | 120.0 | 86.2 | 103.1 | 33.8 | 68.0 | 2298 | + +-------+-------+-------+-------+--------+-------+ + Average | 120.0 | 85.0 | 102.5 | 35.0 | 72.0 | 2550 | +----------+-------+-------+-------+-------+--------+-------+--------------- + (Taken from Weysse and Lutz.) + +In some experiments to determine the changes upon the blood pressure +induced by hot and cold applications on and within the abdomen, Hammett, +Tice and Larson found that heat applied to the outside of the abdomen +raises the blood pressure. The application of cold produces no change. +Either hot or cold saline introduced within the abdomen causes a fall in +blood pressure. + +Experimentally, certain drugs such as adrenalin, barium chloride, +nicotine, digitalis, strophanthus and the infundibular portion of the +pituitary body known as pituitrin raise the maximum pressure. In the +clinic it is difficult to conclude always whether the drug alone is +responsible for rise in maximum pressure. Adrenalin given intravenously +will raise the pressure. So will digitalis and strophanthus. I have +watched the maximum pressure rise within three minutes following an +intravenous injection of gr. 1/100 (0.0006 gm.) strophanthin 20 mm. of +Hg: I have seen the subcutaneous injection of 10 minims of adrenalin +repeated several times daily for six months fail to have the least +effect on the blood pressure picture. + +Elevation of the foot of the bed about nine inches proved so efficacious +in steadying failing hearts in acute infectious diseases, particularly +typhoid, that a study was made of the effect upon blood pressure. Many +observations were made, but no instrumental proof of rise in blood +pressure could be adduced. + +Exercise always raises blood pressure, the maximum much more than the +minimum. In athletes the minimum pressure may actually fall, the maximum +rise so that a greater volume output results from the greater pulse +pressure. + +Shock and hemorrhage lower it. Hemorrhage lowers also the pulse +pressure, and it may be possible to prognosticate internal hemorrhage by +frequent estimations of the systolic and diastolic pressures (Wiggers). +Compression of the superior mesenteric artery or the celiac axis in dogs +raises the blood pressure measured in the carotid artery for a period of +at least an hour. This seems to be dependent on purely mechanical +causes, and is not a reflex vasomotor phenomenon. (Longcope and +McClintock.) + +Experimentally blood pressure can be increased by direct compression of +the brain as Cushing has shown. It was thought at one time that in man +the same effect would result from tumor of the brain or especially from +subdural or extradural hemorrhage following head injuries. This, +however, is not the case. No information of great value can be obtained +by the measurement of blood pressure in these states. We do know that +too high and too prolonged compression of the medulla brings about +exhaustion of the cardiac center accompanied with rapid pulse, low +pressure and eventual death. + + +=Hypertension= + +All the conflict during the past few years over the subject of blood +pressure has revolved around this much overworked word. Hypertension +means high pressure, and yet it carries with it a suggestion of high +pressure which is harmful to the individual. As a matter of fact +hypertension is a compensatory process, it is often a saving process in +spite of the fact that it carries possibilities of harm in its +possessor. It has been made a fetish, a god to fall down before and +worship and it has been the means of holding a torch of fear over a +patient which has not been lost on the charlatans. Popularization of +blood pressure has brought its crop of evils, no one of which has been +as fruitful in dollars to unprincipled quacks as hypertension. + +Hypertension is the expression on the part of the circulation to meet +new conditions in the tissues so that all tissues will be nourished and +all will be enabled to function. Looked at from that point of view it is +a conservative process and in many cases it is. It is not an average +normal state, but it is normal state for the man who has it in chronic +form. Hypertension should be viewed rationally and its proper place in +the whole make-up of the patient determined. Hypertension is a relative +term. What might be high pressure in a man of sedentary habits who +reaches the age of fifty, might not be high pressure in a full blooded +formerly athletic man of the same age. Temporary hypertension due to +excitement, exercise, etc., must be kept in mind. It is not intended to +convey the impression that hypertension is of no moment. It is a matter +for investigation, but not a matter to worship as the all-in-all. + +Hypertension is, after all, a physiologic response on the part of the +organism in order to maintain the circulation in equilibrium in the face +of conditions which tend to produce vasoconstriction in large areas and, +therefore tend to deprive these areas of blood. That there must be some +substance in the blood stream which causes this constriction seems +certain. What it is, is not at present known. Recently, Voegtlin and +Macht[7] have isolated a crystalline substance from the blood of man and +other mammals which they regard as a lipoid and closely related to +cholesterin. This substance was recovered by them from the cortex of the +adrenal gland. This becomes of added interest in the light of +observations made by Gubar (quoted by Voegtlin and Macht). He noted +"that the vasoconstricting properties of blood serum vary in different +pathologic conditions, being increased in nephritis, for instance, and +diminished in others." In some experiments made in the summer of 1913, +we found there was no marked difference in the anaphylactic shock +produced in half-grown rabbits by the injection of normal and uremic +blood serum. As lipoids do not cause anaphylaxis, there should be no +difference in the reaction of normal and uremic sera unless in one there +was some form of protein not in the other. This does not seem to be the +case. The presence of something in the circulation, therefore, produces +constriction of vessels. This calls for more force in contraction on the +part of the heart. This substance may be of lipoid nature. The continued +presence of this hypothetical substance naturally would lead to +hypertrophy of the heart. + + [7] Isolation of a New Vasoconstrictor Substance from the Blood and + the Adrenal Cortex, Jour. Am. Med. Assn., 1913, lxi, 2136. + +What makes hypertension of significance is not the hypertension itself, +but the fact that it is the expression of processes going on in the +body which demand exhaustive investigation. To attach a blood pressure +cuff to the arm, find the pressure, and diagnose hypertension is like +putting a thermometer under the tongue, noting a rise in the mercury, +and diagnosing fever. What causes the hypertension? Can the causes be +removed? Those are the really vital questions after the symptom +hypertension has been discovered. + +All states of hypertension are accompanied by more or less increase of +pulse pressure. In other words the systolic pressure is always increased +to greater degree than the diastolic pressure. In studies carried out in +the wards and Pathological Laboratory of the Milwaukee County Hospital, +Milwaukee, we found that in all of the cases of chronic high blood +pressure with resulting high pulse pressure four correlated factors were +found. If any one of these factors is present, the other three are +found. + +1. In all high pulse pressure cases there is increase in the size of the +cavity of the left ventricle. The ventricle actually contains more blood +when it is full, and throws out, therefore, more blood at each systole. +The actual volume output is greater per unit of time. Such hearts always +show increase in thickness of the ventricular wall. I quite agree with +Stone,[8] who says, "It is merely to be emphasized that when the pulse +pressure persistently equals the diastolic pressure (high pressure +pulse, in other words) with a resulting 50 per cent, _overload_, which +means the expenditure of double the normal amount of kinetic energy on +the part of the heart muscle, cardiac hypertrophy has occurred." They +are found in aortic insufficiency, in chronic nephritis, in the diffuse +fibrous type of arteriosclerosis, and in some cases of exophthalmic +goiter. Such a condition occurs temporarily after exercise. + + [8] Stone, W. J.: The Differentiation of Cerebral and Cardiac Types of + Hyperarterial Tension in Vascular Diseases, Arch. Int. Med., November, + 1915, p. 775. + +2. In all high pulse pressure cases there is actual permanent increase +in diameter of the arch of the aorta. This is a compensating process to +accommodate the increased charge from the left ventricle. Smith and +Kilgore[9] have shown this to be true in cases of chronic nephritis with +hypertension. Their research confirms my own observations. They found +dilatation of the arch in (1) syphilis (that is, aortitis); (2) age over +50 (that is, probable factor of arteriosclerosis); (3) other serious +cardiac enlargement, and (4) hypertension (with more or less +hypertrophy, as in chronic nephritis). + + [9] Smith, W. H., and Kilgore, A. R.: Dilatation of the Arch of the + Aorta in Chronic Nephritis with Hypertension, Am. Jour. Med. Sc., + 1915, cxlix, 503. + +In ten cases showing arches at the upper limit of normal (that is, 6 cm. +in diameter) and hypertrophy of the heart, three were chronic mitral +endocarditis; one was chronic aortic endocarditis; three were chronic +mitral and aortic endocarditis, and there was one each of +hyperthyroidism, pericarditis and adherent pericardium. + +In fourteen cases of hypertension (highest systolic 270 mm., average +systolic, 215 mm.), all showed cardiac hypertrophy. "All but three of +these cases had great vessels whose transverse diameters measured over +the normal limit of 6 cm., and in one of those measuring 6 cm. the +Roentgen-ray diagnosis was 'slight dilatation' of the arch." Smith and +Kilgore are at a loss to explain the three exceptions. They did not give +diastolic pressures, so pulse pressures are not known. Possibly the +three exceptions were cases of high diastolic pressure in which the +pulse pressure possible was not over 60 mm. Such cases might show +"slight dilatation of the arch," but not marked dilatation, such as was +found in the other, evidently high pulse pressure cases. + +We have found that only the high pulse pressure cases show dilatation of +the arch. Certain high tension cases which have had a very high +diastolic pressure do not reveal any accurately measurable dilatation of +the aortic arch. An empty aorta after death is quite different from a +functionating aorta during life. Hence the dilatation which is found +postmortem must have been considerable during life. And conversely, a +dilatation which was present during life might not be looked on as such +after death. + +3. In all high pulse pressure cases one will find on careful +auscultation over the manubrium, particularly its lower half, breath +sounds which vary from bronchial to intensely tubular. At times the +percussion note will be slightly impaired, as McCrae[10] has shown in +dilatation of the arch of the aorta. This auscultatory sign is evidence +of some more or less solid body in the anterior mediastinum which is +lying on the trachea and permits the normal tubular breathing in the +trachea to be audible over the upper part of the sternum. It is found in +cases of dilated aortic arch. Fluoroscopic examination has confirmed the +findings on auscultation. + + [10] McCrae, Thomas: Dilatation of the Arch of the Aorta, Am. Jour. + Med. Sc., 1910, cxl, 469. + +4. In all high pulse pressure cases, in which the pulse pressure is over +70 mm. of mercury, there is increase in the size of all large +distributing arteries, carotids, brachials, femorals, renals, celiac +axis, etc., with fibrous changes in the media, loss of some of the +elasticity, and in the palpable superficial arteries, increase in size +of the pulse wave. + +Increased pulse pressure means increased volume output, but does not +always mean increased velocity. The proper distribution of blood to the +various organs of the body is regulated by the vasomotor system acting +on the small arteries which contain considerable unstriated muscle. In +order that there may be enough blood at all times and under varying +conditions of rest and function, there must be a proper supply coming +through the distributing vessels, the large arteries, those containing +much elastic tissue, and only a very small amount of unstriated muscle +tissue or none whatever. Fibrous sclerosis of these vessels causes them +to become enlarged and tortuous and to lose much of their elasticity, +which is essential for the even distribution of blood. A greater blood +volume is therefore necessary in order that the organs may receive their +quota of blood. A force which is sufficient to send blood through +elastic normal distributing tubes becomes totally insufficient to send +the same amount of blood through tortuous and more or less inelastic +tubes. As a compensatory process the pulse pressure increases. For this +to increase, the left ventricular cavity dilates, the arch dilates, and +as a greater force must be exerted to keep the increased mass in motion, +the heart responds by hypertrophy of its left ventricle and becomes +itself the subject of fibrous changes in the myocardium. The mass +movement of blood is therefore greater in high pulse pressure cases than +in cases of normal pulse pressure. + +In cases of chronic interstitial nephritis--contracted granular +kidney--it may well be that the sclerosis of the arteries is a secondary +process caused, as Adami thinks, by the hypertension itself. In aortic +insufficiency the situation is somewhat different. The high pulse +pressure is due to a very low diastolic pressure, for in my experience +with uncomplicated aortic insufficiency the systolic pressure is, as a +rule, not much increased above the normal for the individual's age. Here +peripheral resistance is so low that a capillary pulse is common. The +volume output per unit of time is greatly increased, the arch of the +aorta is dilated, and the pulse is large. The fact that a large part of +the blood regurgitates during diastole back into the ventricle, and the +fact that the diastolic pressure is low means that there is no increased +resistance to overcome, and the systolic pressure is not raised. + +Stone[11] has divided the cases of hypertension into the cerebral and +cardiac types. He finds that there is a difference in prognosis and in +the mode of death in the two groups. He has further attempted to judge +of the work placed upon the heart by calculating what he calls the +heart load or pressure-ratio. For example, he takes a normal pressure at +120-80-40. The relation between 80 and 40 is 1/2 or 50 per cent. That he +considers normal. When the heart load increases so that the pulse +pressure equals or exceeds the diastolic pressure, the heart load is 100 +per cent or more, he considers the danger of myocardial exhaustion +graver than when the heart load is normal or less than 50 per cent. + + [11] Stone, W. J.: Arch. Int. Med., 1915, xvl, 775. + +It is his opinion, in which I heartily concur, "that an individual with +a systolic pressure of 200 and a diastolic pressure of 140, is in +greater danger of cerebral death than an individual with a systolic +pressure of 200 and a diastolic pressure of 100." He is "likewise +certain that the individual with a systolic pressure of 200 and a +diastolic of 90 to 100 is in greater danger of a cardiac death. It is +apparently the constant high diastolic pressure rather than the +intermittently high systolic pressure which predisposes to cerebral +accident." + +I have not been able to confirm all of Stone's conclusions. His +contention holds good for some cases, but not, in my experience, for the +great majority of the hypertension cases. I feel that in the +classification of the chronic high pressure case we can go one step +farther and split his first group into two usually differentiable +groups. Syphilis is not an etiological factor in any of these groups. It +is not considered that these groups are absolutely distinct and can +always be rigidly separated. There are variations and combinations which +render an exact separation impossible. But bearing this in mind the +following classification is proposed as a working classification. + +Group A. Chronic nephritis. + +Group B. Essential hypertension. + +Group C. Arteriosclerotic hypertension. + +Group A. _Chronic Nephritis._ These are the cases with a high-pressure +picture, that is to say, high systolic (200+) and high diastolic +(120-140+). The pulse pressure is much increased. The palpable arteries +are hard and fibrous. There is puffiness of the under eyelids, which is +more pronounced in the morning on arising. Polyuria with low specific +gravity and nycturia are present. There are almost constant traces of +albumin in the urine, with hyaline and finely granular casts. + +Functionally these kidneys are much under normal. The functional +capacity determined by Mosenthal's modification of the Schlayer-Hedinger +method shows a marked inability to concentrate salts and nitrogen. The +phthalein output is below normal. As the case advances the phthalein +output becomes less and less, until a period is reached when there are +only traces or complete suppression at the end of a two-hour period. +Such patients may live for ten weeks (one of our cases) or longer, all +the time showing mild uremic symptoms, and suddenly pass into coma and +die. + +The natural end of patients in this group is either uremia or cardiac +decompensation (so-called cardiorenal disease). Cerebral accidents may +happen to a small number. It is only to this group, in my opinion, that +the term cardiorenal disease should be applied. Formerly I believed that +all high systolic pressure cases were cases of chronic nephritis of some +definite degree. From the purely pathologic standpoint that is true, but +from the important, functional standpoint it is far from being the true +state of the cases. + +In this group there is marked hypertrophy and moderate dilatation of the +left ventricle with dilatation and nodular sclerosis of the aorta. The +kidneys are firm, red, small, coarsely granular, the cortex much +reduced, the capsule adherent. Cysts are common. It is the familiar +primary contracted kidney. Mallory calls this capsular-glomerulonephritis. +The etiology is obscure. Often no cause can be found. Again, there is a +history of some kidney involvement following one of the acute infectious +diseases, or it may follow the nephritis of pregnancy. Usually, however, +these cases fall into the group of secondary contracted kidneys, chronic +parenchymatous nephritis. + + Illustrative Case.--R. Z., a woman, aged thirty-six years, was seen + July 26, 1916, in coma. There was a history of typhoid fever at + nineteen years, but no other disease. She had had nine full-term + pregnancies, the last one thirteen months previously. For a week + before the onset of the present illness she had complained of severe + headaches and dizziness. There were no heart symptoms. For the past + year she has had nycturia. Physical examination revealed tubular + breathing beneath the manubrium, a few rales in the chest, an + enlarged heart (left side), with a systolic murmur over the aortic + area. Blood pressure was 178-125-53, the pulse rate 96, leucocytes + 27,250. Venesection of 500 c.c. of blood and intravenous injections + of 500 c.c. of 5 per cent NaHCO_3 in normal saline were employed. + Lumbar puncture withdrew 60 c.c. of clear fluid under pressure with + 6 cells per cubic millimeter. The eye grounds showed distinct + haziness of the disks and dilatation of the veins. Blood pressure + after venesection was 164-122-42, pulse 76, but in a few days rose + to 222-142-80, pulse 70. A second venesection of 400 c.c. and + proctoclysis of 1000 c.c. saline solution was tried. The + blood-pressure now was 198-140-58. The pH of the blood was 7.6, the + alkaline reserve was 35 volume per cent (van Slyke), and the CO_2 + tension of the alveolar air (Marriott) was 25 mm. The phthalein on + the day following the second venesection was 45 per cent in two + hours. The urine at first showed 500 c.c. in twenty-four hours, + specific gravity 1016, albumin and casts. Later she passed 1300 to + 1600 c.c. with specific gravity around 1010. The blood-pressure + fluctuated considerably, reaching as low as 138-98-40, pulse 88. She + was discharged improved September 10, 1916. She had constant + headache but managed to keep up. In June, 1917, she suddenly died in + an uremic coma. + +Group B. This one might designate as the hereditary type, although there +is not always a history in the antecedent. This group includes the +robust, florid, exuberantly healthy people. They often are heard to +boast that they have never had a doctor in their lives. They are usually +thick-set or very large, fleshy people. The pressure picture is +exceedingly high. The pulse pressure is moderately increased. The +arteries are rather large, fibrous, and often quite tortuous, although +this is not always the case. Some persons have hard, small, fibrous +arteries. There is no puffiness beneath the eyes, no polyuria, and no +nycturia as a rule. The urine is of normal amount, color, and specific +gravity. Albumin is only rarely found and then in traces, but careful +search of a centrifuged specimen invariably reveals a few hyaline +casts. The phthalein excretion is normal or only slightly reduced. The +kidneys excrete salt and nitrogen normally. It is in this group that +apoplexy is found most frequently. The rupture of the vessel occurs when +the victim is in perfect health, often without any warning. Occasionally +when such a case recovers sufficiently to be around, cardiac +decompensation sets in later and he dies then of the cardiac +complications. + +Pathologically the hearts of such persons are found to have the most +enormous hypertrophy of the wall of the left ventricle. The cavity is +somewhat enlarged, as is always the case when the pulse-pressure is +increased, but the size of the cavity is not the striking feature. The +aorta is fibrous, thick walled, and the arch is slightly dilated. There +are patches of arteriosclerosis. One such case seen only at autopsy had +a rupture of the aorta just above the sinus of Valsalva and died of +hemopericardium. The kidneys are of normal size, dark red, firm, the +capsule strips readily, the surface is smooth or finely granular, the +cortex is not decreased. The pyramids are congested and red streaks +extend into the cortex. Microscopically the capsules of the glomeruli +are a trifle thickened; a few show hyaline changes. There is rather +diffuse, mild, round-cell infiltration between the tubules. The tubular +epithelium shows little or no demonstrable changes. The arterioles are +generally the seat of a moderate thickening of the intima and media, but +it is not usual to find obliterating endarteritis. There is evidently a +diffuse fibrous change which has not affected either the tubules or +glomeruli to any great extent. + + Illustrative Case.--L. C., a man, aged fifty-six years, stonemason + by trade, is a stocky, thick-necked individual. He had never been + ill in his life until a year ago, when he fell from his chair + unconscious. He had a right-sided hemiplegia which has cleared up so + completely that except for a very slight drag to his foot he walks + perfectly well. He came in complaining of shortness of breath and + cough. There was no swelling of the feet. Here evidently was + left-heart decompensation. Examination showed the blood pressure to + be 240-130-110, pulse irregular, 104 to the minute. There were + cyanosis and rales throughout both chests. The urine was normal in + color, specific gravity 1025, small amount of albumin, few casts, + hyaline and granular. The phthalein elimination was 65 per cent in + two hours. Under rest, purgatives, and digitalis he was much + improved. He has since had two other apoplectic strokes, the last of + which was fatal. + +When these patients are seen with acute cardiac decompensation, there +are, of course, much albumin and many casts in the urine, and the +phthalein output is, for the time being, decreased. + +Group C. This might be called the arteriosclerotic high-tension group +(Stone's cardiac group). The cases are usually over fifty years old. +They are men and women who have lived high and thought hard. Often they +have had periods of great mental strain. Many men in this group were +athletes in their young manhood. Many have been fairly heavy drinkers, +although never drinking to excess. They are usually well nourished and +inclined to stoutness. The pressure picture is high systolic with normal +or only slightly increased diastolic and large pulse pressure. The +arteries are large, full, fibrous, usually tortuous. The heart is very +large, the apex far down and out. There is no polyuria; nycturia is +uncommon, quite the exception. The urine is normal in color, amount, and +specific gravity. Albumin is only rarely found and hyaline casts are not +invariably present. The phthalein excretion is quite normal and the +excretions of salt and nitrogen are also normal. The terminal condition +in most of the patients in this group is cardiac decompensation. They +may have several attacks from which they recover, but after every attack +the succeeding one is produced by less exertion than the preceding one, +and it becomes more and more difficult to control attacks. Eventually +the patients become bed- or chair-ridden, and finally die of acute +dilatation of the heart. + +Occasionally patients in this group may have a cerebral attack, but in +my experience this is uncommon. Pathologically the heart is large, at +times true _cor bovinum_, dilated and hypertrophied. The cavity of the +left ventricle is much dilated. The aorta is dilated and sclerosed. + +The kidneys are increased in size, are firm, dark red in color, with +fatty streaks in the cortex. The capsule strips readily and the cortex +is normal in thickness or only slightly increased. The organ offers some +resistance to the knife. The microscope shows small areas scattered +throughout where the glomeruli are hyalinized, the stroma full of small +round cells, the tubules dilated, and the cells are almost bare of +protoplasm. Naturally the tubules are full of granular cast material. +Also the arterioles show extensive intimal thickening, fibrous in +character, with occasional obliterating endarteritis. One gets the +impression that the small sclerotic lesions are the result of anemia and +gradual replacement of scattered glomeruli by fibrous tissue. For the +most part the kidney, except for the chronic passive congestion, appears +quite normal. One can readily understand that in such a kidney function +could not have been much interfered with. + + Illustrative Case.--C. K., an active, stout, business man, aged + fifty-six years, consulted me on account of shortness of breath and + swelling of the feet in May, 1915. He had just returned from a + hospital in another city, where he had gone with what was apparently + cardiac decompensation. In his early manhood he had been a gymnast + and a prize winner. He has worked hard, often given way to violent + paroxysms of temper, has eaten heavily but drunk very moderately. + The heart was greatly enlarged, the arch of the aorta dilated, a + mitral murmur was audible at the apex. The radials and temporals + were large, tortuous, and fibrous. The blood pressure picture ranged + around 180-90-90. He was easily made dyspneic and had a tendency to + swelling of the lower legs. The urine was acid, of normal specific + gravity, normal in amount, normal phthalein, normal concentration of + salt and nitrogen, contained albumin only when he was suffering from + decompensation of the heart. Casts were always found. He finally + died, after sixteen months, with all the symptoms of chronic + myocardial insufficiency. The heart was enormous, a true _cor + bovinum_. The kidneys were typical of this condition, possibly + somewhat larger than usual. + + +=Hypotension= + +When the pressure is constantly below the normal, it is called +hypotension. This may be transient--as in fainting--it may be a normal +state of the individual, it occurs in most fevers and in a great +variety of diseases, including anemias. + +In arteriosclerosis, especially the diffuse (senile) type, the blood +pressure is invariably low, and may be spoken of as hypotension. The +heart in such a case is small, the muscle is flabby, there is brown +atrophy of the fibers, and some replacement of the muscle cells by +connective tissue. The same causes which have produced general +arteriosclerosis have also produced sclerosis of the coronary arteries, +and probably the lessened blood supply accounts for much of the atrophy +of the heart muscle. + +In typhoid fever the maximum blood pressure during beginning +convalescence may be as low as 65 mm. Hg. I have frequently seen +hypotension of 80 mm. This is common. + +Meningitis is the only acute infectious disease in which the blood +pressure is more often high than low. This is accounted for by the +increased intracranial tension. + +Following large hemorrhages the blood pressure is reduced. In +venesection the withdrawal of blood may not affect the blood pressure. +The procedure is done to relieve overdistension of the heart. + +In pleurisy with effusion and in pericarditis with effusion there is +hypotension. + +Collapse, whether from poisoning by drugs or as the result of dysentery, +cholera, or profuse vomiting from whatever cause, reduces the blood +pressure. + +In cachectic states, such as cancer, the blood pressure is low. General +wasting of the whole musculature includes that of the heart and the +heart muscle shows the condition known as "brown atrophy." + +A most interesting and important condition in which hypotension occurs +is pulmonary tuberculosis. Haven Emerson has recently gone over the +whole subject in a careful piece of work and his summary is as follows: + +"Hypotension or subnormal blood pressure is universally found in +advanced pulmonary tuberculosis, in which condition emaciation may play +a part in its causation. Hypotension is found in almost all cases of +moderately advanced tuberculosis, or in early cases in which the toxemia +is marked except when arteriosclerosis, the so-called arthritic or gouty +diathesis, chronic nephritis, or diabetes complicate the tuberculosis +and bring about a normal pressure or a hypertension. Occasionally the +period just preceding a hemoptysis or during a hemoptysis may show +hypertension in a patient whose usual condition is that of hypotension. + +"Hypotension has been found by so many observers in early, doubtful or +suspected cases with or before physical signs of the disease in the +lungs, and is considered by competent clinicians so useful a +differential sign between various conditions and tuberculosis, that it +should be sought for as carefully as it is the custom at present to +search for pulmonary signs. + +"Hypotension when found persistently in individuals or families or +classes living under certain unhygienic conditions should put us on our +guard against at least a predisposition to tuberculosis. Most unhygienic +conditions, overwork, undernourishment and insufficient air, are of +themselves causes of a diminished resistance, and it seems likely that a +failure of normal cardiovascular response to exercise or change of +position may be found to indicate this stage of susceptibility, +especially to tuberculous infection. + +"... Hypotension, when it is present in tuberculosis, increases with an +extension of the process. Recovery from hypotension accompanies arrest +or improvement. Return to normal pressure is commonly found in those who +are cured. Continuation of hypotension seems never to accompany +improvement. Prognosis can as safely be based on the alteration in the +blood pressure as on changes in the pulse or temperature...." + +There are a few drugs which lower the blood pressure, but, as a rule, +their effects are more or less transitory. We know of no drug, unless it +be iodide of potassium, which has the property of causing changes in the +blood (decrease in viscosity?), which tends to reduce the blood pressure +when it is excessive. This drug fails us many times. + + +SOME DRUGS WHICH INFLUENCE THE BLOOD PRESSURE + + =Pressure Raisers= + + Adrenalin, when injected directly + into a vein or deep into the muscles. + The action is transitory. + + Caffeine, preferably in the form + of caffeine-sodium-benzoate. A good + drug. + + Strychnine, which does not act directly + but seemingly through the + higher centers. + + Ergot, somewhat uncertain. + + Nicotine, not used therapeutically. + + Camphor, used in sterile olive oil + and injected deeply into the muscles. + + Digitalis, when the cardiac tone is + low and decompensation is present. + Its action is prolonged but slow. Injections + of the infundibular portion + of the pituitary body. Not in use + clinically. + + + =Pressure Depressors= + + Nitroglycerine and amyl nitrite, + action transitory but rapid. + + Sodium nitrite and erythrol tetranitrate. + Action somewhat more prolonged. + + Aconite, veratrum viride, chloral, + etc. These depress the heart. + + Purgatives, drastic and hydragogue. + + Potassium and sodium iodide may + lower blood pressure. When they do, + the action is prolonged. + + Diuretin and theocin-sodium-acetate. + + +=Venous Pressure= + +Comparatively little work has been done upon the determination of the +pressure in the veins in man. It is conceivable that this procedure may, +at times, be of great value. A number of attempts have been made to +measure the venous pressure by compressing the arm veins and noting on a +manometer the force necessary to obliterate the vein. As the pressure is +so slight, water is used instead of mercury, and readings have been +given in centimeters of water. + +[Illustration: Fig. 33.--Apparatus for estimating the venous blood +pressure in man, devised by Drs. Hooker and Eyster. The small figure is +the detail of the box B. See explanation in text.] + +In the apparatus shown in the figure (Fig. 33), Drs. Hooker and Eyster +succeeded in making estimations of the venous pressure. The box _B_ is +held in position by the tapes _A_, so that the vein is visible through +the rectangular opening in the thin rubber covering the bottom. The box +is connected with the water manometer _G_, by a rubber tube, from which +a T-tube enters the rubber bulb _E_. When the bulb _E_ is compressed +between the plates _D_, by the coarse thumbscrew _C_, air is forced +into the box _B_, exerting a pressure on the vein lying exposed beneath. +This pressure is transmitted directly to the manometer =G=, and may be +read off in centimeters of water on the accompanying scale. The veins of +the back of the hand are used and there must be no obstruction between +them and the heart. The rubber-covered box is accurately and lightly +fitted over a vein and pressure made until it is obliterated. By +measuring the distance above or below the heart level that the hand was +when the observation was made, and subtracting or adding these figures +to the manometer reading, we obtain the venous pressure at the heart +level. + +Eyster has modified this instrument so that it is now much simpler to +operate. He uses a small glass cup with a flaring edge and a diameter of +about 2 cm. This is sealed to the skin directly over a vein on the back +of the hand by means of collodion. The stem of the cup has a rubber tube +leading to a small hand bulb and to the manometer tube which contains +colored water. Slight compression of the hand bulb obliterates the vein +which can be seen through the glass cup. The pressure in centimeters of +water is then read off. (Fig. 34.) The principle is the same as in the +earlier instrument, but the application is easier. + +[Illustration: Fig. 34.--New venous pressure instrument. (After +Eyster.)] + +Practically Hooker and Eyster found that the normal variation in healthy +subjects was from 3 to 10 cm. of water. The pressure rose in cases of +decompensated hearts with dyspnea and venous stasis, and returned to +normal with improvement in the condition of the patient. It might be +possible with this instrument to foretell an oncoming decompensation by +the rise in venous pressure. + +The venous pressure may also be estimated roughly by slowly elevating +the arm and noting the instant at which a particular vein collapses. By +measuring the height of the vein above the heart some idea may be +obtained of the pressure within the right auricle. + + +=The Pulse= + +There is nothing characteristic about the pulse of a person suffering +from arteriosclerosis, except it be the difference in the pulse of high +tension and of low tension. The pulse of high tension has a gradual +rise, a more or less rounded apex, and the dicrotic wave is slightly +marked and occurs about half-way down on the descending limb. In +arteriosclerosis with low tension the radial artery is usually so rigid +that very little pulse wave can be obtained. The general form of a low +tension pulse is a sharp upstroke, a pointed summit, and a secondary +wave on the base line, which corresponds to the dicrotic wave. Such a +pulse can be easily palpated, and is known as a dicrotic pulse. However, +such a pulse can occur only when the artery still retains all or a large +part of its elasticity; hence in arteriosclerotic low tension we would +never see such a pulse as the typical dicrotic. + + +=The Venous Pulse= + +It would carry us too far to discuss fully the character of the venous +pulse, but a brief summary of the essential features of the normal +venous pulse is presented. The venous pulse is a term used to express +the tracing obtained from the internal or external jugular vein at the +root of the neck. Normally a very characteristic curve is produced, +which can be readily analyzed into a series of waves corresponding to +the fluctuations in the cardiac cycle. To understand these waves and +their values, the accompanying figure is helpful. (Fig. 35.) + +[Illustration: Fig. 35.--Semidiagrammatic representation of the events +in the cardiac cycle: Jug., pulse in the jugular vein; Aur., contraction +of auricle; V. Pr., intraventricular pressure; Pap. M., contraction of +the papillary muscles; Car., carotid pulse. Below are given the times of +occurrence of the heart sounds and of the opening and closing of the +heart valves. (After Hirschfelder.)] + +Bachmann summarizes the normal waves in the venous pulse tracing as +follows: + +"The physiological or so-called venous pulse consists of three positive +and three negative waves, bearing a more or less definite relation to +the events of the cardiac cycle, and having their origin in the various +movements of the chambers and structures of the right heart. The first +positive wave (_a_) is presystolic in time, and is due to the +contraction of the auricle, causing a slowing of the venous current and +producing a centrifugal wave through a sudden arrest of the inflowing +blood. The second positive wave (_S_) is presystolic in time, and +originates in the sudden projection of the tricuspid valve into the +cavity of the auricle during the quick, incipient rise in the +intraventricular pressure occurring in the protosystolic period. The +third positive wave (_v_) occurs toward the end of ventricular systole. +It consists of two lesser waves separated by a shallow notch. The +factors entering into its formation are the relaxation of the papillary +muscle at a time when the intraventricular is still higher than the +intraauricular pressure, resulting in an upward movement of the +tricuspid leaflets and a return of the auriculoventricular septum to its +position of rest. + +"The first negative wave (between positive wave _a_ and _S_) is due to +the relaxing auricle. The second negative wave (_Af_) occurs during the +diastole of the auricle. It is due to the dilatation of its walls, to +the displacement of the auriculoventricular septum toward the apex +occurring at the time of ventricular systole, and to the pull of the +papillary muscles on the tricuspid valve leaflets. The third negative +wave (_Vf_) appears during ventricular diastole and in the common pause +of the heart chambers. Its cause is found in the passage of the blood +from the auricle into the ventricle. It is somewhat modified possibly by +the continual ascent of the auriculoventricular septum and by a wave of +stasis due to the accumulation of blood coming from the periphery." +(Fig. 36.) + +[Illustration: Fig. 36.--Simultaneous tracings of the jugular and +carotid pulses showing normal waves in the venous pulse and relation to +carotid pulse. (After Bachmann.)] + +Hirschfelder has described another wave which he calls the "h" wave, +which is due to the floating up of the tricuspid valve by the blood in +the ventricle before the complete filling of the ventricle following the +auricular systole. (Fig. 37.) + +[Illustration: Fig. 37.--Jugular and carotid tracing from a normal +individual with a well-marked third heart sound showing a large "h" and +a smaller pre-auricular wave "w." ? indicates a small wave in +mid-diastole following the "h" wave, occasionally found though perhaps +an artefact. (After Hirschfelder.)] + + +=The Electrocardiogram= + +In the past few years an immense amount of work has been done by +numerous observers on the changes in the electrical potential of the +various portions of the heart during contraction. The very elaborate and +delicate electrocardiograph with the string galvanometer devised by +Einthoven is used. It has been definitely determined that the impulse to +cardiac contraction originates in the sinus node, a collection of +differentiated nerve cells situated at the junction of the superior vena +cava with the right auricle. From there the impulse travels in certain +fibers in the interauricular wall, passes through another node, the +auriculoventricular or Tawara node, situated in the auricular wall just +above the auriculoventricular ring, thence via the Y-bundle, or bundle +of His to the ventricles. This sequence is orderly, regular, and +normally invariable. (Fig. 38.) + +[Illustration: Fig. 38.--Right side of the heart showing +diagrammatically the distribution of the two vagus nerves to different +parts of the viscus. The impulse to contraction originates at the +sino-auricular node and passes over the wall of the auricle to Tawara's +node, and thence over His' bundle across the auriculoventricular septum +to be distributed throughout the ventricular wall. If the upper, +sino-auricular, node is damaged, or if its impulses fail to get across +the wall of the auricle, Tawara's node acts in its place to start off +the ventricle. If a lesion at the base of the mesial segment of the +tricuspid valve damages His' bundle, so that Tawara's node is cut off +from the ventricle, then the ventricle may originate its own impulses to +contraction. (Hare's Practice of Medicine.)] + +The sino-auricular (s-a) node is the most irritable portion of the +heart, it is endowed with the greatest amount of rhythmicity as well. +It is under the control of the vagus nerve. Its inherent rate of +rhythmicity is probably more rapid than the usual numbers of impulses +per minute, but it is inhibited by the vagus. Paralysis of the vagus +endings increases the rate of impulse formation and therefore the rate +of the heart. + +The electrocardiogram is a graphic representation on a photographic film +or sensitive bromide paper of the changes of electrical potential during +muscular activity. The lines are made by the highly magnified string of +the galvanometer as it moves across the slit in the photographic +apparatus in response to the induction currents set up in the heart +magnified by the special galvanometer. + +The record is made in three so-called Leads. + + Lead I + + The electrodes are attached to right arm and left arm. + + Lead II + + The electrodes are attached to right arm and left leg. + + Lead III + + The electrodes are attached to left arm and left leg. + +A series of regular figures is normally obtained in which are +depressions and elevations and regular spacing of these elevations and +depressions. The waves so-called have been arbitrarily designated _P_, +_Q_, _R_, _S_, _T_. There is some difference in the three leads. "The +wave _P_ is positive in _all leads_. _P_ to _R_ interval varies slightly +in the _three leads_. All the waves of _Lead II_ are greater than those +of _Leads I_ and _III_. The wave _R_ is positive in _all leads_. _T_ is +usually positive in _all leads_, but is occasionally negative in Lead +III. Even in normal individuals there is a considerable range of +variation in the electrocardiogram which is within the limits of the +normal." (Hart.) (Fig. 39.) + +[Illustration: Fig. 39.--Normal electrocardiogram. (After Hart.)] + +The _P_ wave is admitted to be the wave of auricular contraction. _Q_, +_R_, _S_, is the ventricular complex caused, it is thought, by the +current passing over the ventricles. _T_ wave is not yet definitely +settled. It has been thought by some that it represented actual +ventricular contraction and its height and shape had some meaning in +heart force. This is denied by others. Hart defines it as "The final +activity of the ventricle." The _T_ wave is usually increased in size +during exercise. + +The _P-R_ interval is almost the most important feature of the tracing. +It is the actual conduction time in fractions of a second of the impulse +from s-a node to the ventricles. Normally this is about 0.2 second or +slightly less. Much that was hoped for from the electrocardiograph in +the clinic has not been forthcoming. Its greatest value is in states of +abnormal conductivity, such as various grades of heart block, +extrasystoles, whether originating in auricles or in either ventricle, +abnormalities of rhythm, as flutter and fibrillation. It has, however, +aided materially in the intelligent interpretation of many phenomena +heretofore not well understood, and has enormously increased our +knowledge of the physiology and pathologic physiology of the heart. + +It is not possible to enter farther into the subject here. This brief +discussion must suffice. The reader is referred to works on this subject +in connection with diseases of the heart. + + + + +CHAPTER IV + +IMPORTANT CARDIAC IRREGULARITIES ASSOCIATED WITH ARTERIOSCLEROSIS + + +Arteriosclerosis of the aorta, of the coronary arteries, or of both, is +practically always found in cases dying of various cardiac +irregularities other than those the result of rheumatic cardiac lesions. +It is not that arteriosclerosis causes the cardiac lesions (although the +thickening of the walls of the coronary arteries does interfere +mechanically with the nutrition of the heart muscle), but the +arteriosclerosis is a part of the tissue reaction in the arteries to +some set of causes affecting the whole body. It is true when one boils +down the question to its last analysis, general arteriosclerosis may +mechanically so interfere with the blood supply to tissues that the +tissue is thrown out of function either in the reduction or even loss of +function. So it may be that occasionally the arteriosclerosis in the +arteries supplying the heart is really responsible for the cardiac +irregularity. The past few years have been fruitful ones in increasing +our knowledge of the various irregularities of the heart. We can do no +more than sketch briefly some of them in relation to arteriosclerosis. + +The chief irregularities are (1) auricular flutter, (2) auricular +fibrillation, (3) ventricular fibrillation, (4) auricular extrasystole, +(5) ventricular extrasystole, (6) heart block, partial or complete. + + +=Auricular Flutter= + +Auricular flutter is an abnormal rhythm characterized by very rapid, but +rhythmic auricular contractions usually 250 to 300 per minute. The +auricular contractions are so rapid that the ventricle can not respond, +so that an electrocardiagram of a heart in such a state (Fig. 40) shows +the ventricle beating regularly but at a much slower rate than the +auricle. + +[Illustration: Fig. 40.--(After Hart.)] + +The majority of cases exhibiting this peculiar rhythm are over 40 years +of age. In many cases sclerosis of the coronary arteries as a part of +general arteriosclerosis has been found. Auricular flutter can be +suspected when the pulse is regular or not particularly irregular and a +fluttering, rapid pulsation is seen in the jugular vein on the right +side. One can only be sure of the condition by making graphic records of +the heart. + +Attacks usually come on suddenly and may disappear as suddenly, +suggesting paroxysmal tachycardia. The patient feels a commotion in his +chest, dyspnea, precordial distress, etc. The attack may last for weeks +or months, in which case the patient may carry on his usual work but be +conscious of palpitation in his chest. One may safely assume that the +flutter is a sign of a failing myocardium and sooner or later the heart +will pass to the graver stage of auricular fibrillation. + + +=Auricular Fibrillation= + +In this condition the auricle is widely dilated and over its surface are +countless twitchings of individual muscles giving to the auricle the +appearance of a squirming bunch of worms. Such a condition may be +readily produced in a dog's exposed heart by direct faradization of the +auricle. It should be seen by every physician in order fully to +appreciate the passive, dilated sac part which the auricle plays when in +such a state. There is no auricular wave on the electrocardiogram (Figs. +41 and 42) only a series of fine tremulous lines, and the ventricles +beat irregularly with many dropped beats and variations in the size and +force of individual beats. Extrasystoles are also frequent. The heart is +absolutely irregular. Such a condition is readily recognizable as the +state of broken compensation. Graphic records are not essential as in +auricular flutter to establish the condition. Inspection of the root of +the neck for jugular pulsations and examination of the pulse with the +patient's evident dyspneic, cyanotic, edematous condition settles the +diagnosis. + +[Illustration: Fig. 41.--Electrocardiogram showing auricular +fibrillation in Leads I (upper) and II (middle and lower). (Courtesy of +Dr. G. C. Robinson.)] + +[Illustration: Fig. 42.--Auricular fibrillation. (After Hart.)] + +In no case of auricular fibrillation is the heart muscle free from +extensive fibrous changes. These may be the result of general +arteriosclerotic changes or may result from toxic changes. It is the +general consensus of opinion that auricular fibrillation may persist for +months or even years. Some hold that the state of perpetual irregular +pulse is associated with auricular fibrillation. If that is true, then +auricular fibrillation may last for many years. Patients may go about +their work but always live with the imminent danger of a sudden +dilatation of the ventricle and symptoms of acute cardiac +decompensation. + +In these cases the blood pressure is of particular interest. It is often +stated that the blood pressure is lowered as compensation returns and +digitalis has exhibited its full action. As a matter of fact this +statement needs some modification. If one takes the highest pressure at +the strongest beat, which may be only one in a dozen or more, that may +be true, but that does not represent the action of the much embarrassed +heart. We know that the circulation is much interfered with, that there +is hypostatic congestion, that the mass action is slow. The pulse +pressure is greatly disturbed and the head of pressure which should +force the blood to the periphery is so little that the circulation +almost ceases. + +A count of the cardiac contractions heard with the stethoscope and a +count of the pulse shows a great discrepancy in number. This has been +called the "pulse deficit" (Hart). In order to arrive at the true +average systolic pressure the following procedure is done. "The apex and +radial are counted for one minute, at the same time by two observers, +(if possible) then a blood pressure cuff is applied to the arm, and the +pressure raised until the radial pulse is completely obliterated; the +pressure is then lowered 10 mm., and a second radial count is made; this +count is repeated at intervals of 10 mm. lowered pressure until the +cuff-pressure is insufficient to cut off any of the radial waves +(between each estimation the pressure on the arm should be lowered to +zero). From the figures thus obtained the average systolic blood +pressure is calculated by multiplying the number of radial beats by the +pressures under which they came through, adding together these products +and dividing their sum by the number of apex-beats per minute, the +resulting figure is what we have called the 'average systolic blood +pressure.'" (Fig. 43.) + +[Illustration: Fig. 43.--The shaded area represents the pulse deficit; +the upper edge is the apex rate, the lower edge the radial rate. The +broken line indicates the "average systolic blood pressure." (Compare +these values with the figures at the bottom of the chart, which show the +systolic blood pressure determined by the usual method.) (After Hart.)] + +For example: "B. S., April 29, 1910, Apex 131; radial, 101; deficit, 30. + + BRACHIAL PRESSURE RADIAL COUNT + 100 mm. Hg. 0 + 90 mm. 13 13 x 90 = 1170 + 80 mm. 47 - 13 = 34 x 80 = 2720 + 70 mm. 75 - 47 = 28 x 70 = 1960 + 60 mm. 82 - 75 = 7 x 60 = 420 + 50 mm. 101 - 82 = 19 x 50 = 950 + ---- + Apex = 131) 7220 + ---- + Average systolic blood-pressure 55 plus + +B. S., May 11, 1910, Apex 79; radial, 72; deficit 7. + + BRACHIAL PRESSURE RADIAL COUNT + 120 mm. Hg. 0 + 110 mm. 44 44 x 110 = 4840 + 100 mm. 64 - 44 = 20 x 100 = 2000 + 90 mm. 72 - 64 = 8 x 90 = 720 + ---- + Apex = 79) 7560 + ---- + Average systolic blood-pressure 95 plus" + +The diastolic pressure in these cases can not be determined except +approximately. This may be done by using an instrument with a dial and +noting the pressure where the oscillations of the dial hand show the +maximum excursion. The diastolic pressure is not at all important under +such conditions of acute cardiac breakdown. It would make no difference +in treatment whether the case was one of pure cardiac disease or one +of the hypertension groups. After the heart has rallied and the +circulation is reestablished, then a careful determination of the +diastolic pressure can be made and the prognosis will rest on what is +found at the compensated stage. + + +=Ventricular Fibrillation= + +Ventricular fibrillation as its name implies, is fibrillation of the +ventricle analogous to that of the auricle, but the condition is rarely +observed as it is incompatible with life. It has been shown that hearts +at the time of death at times enter a state of fibrillation of the +ventricles and that cases of sudden death may be due to this condition. +Recently G. Canby Robinson[12] has seen and made electrocardiograms of a +case of ventricular fibrillation. (Fig. 44.) The case was that of a +woman forty-five years old, "who had a series of attacks of prolonged +cardiac syncope, closely resembling Stokes-Adams syndrome, from which +she recovered." During an attack of unconsciousness in which there was +no apex beat for about four minutes, the electrocardiogram was taken. +Following this the tracings showed an almost regular heart beating at +the rate of 85 to 100 per minute. The patient had three convulsions and +died with edema of lungs about 30 hours after the attack of ventricular +fibrillation. + + [12] Robinson, G. C., and Bredeck, J. F.: Arch. Int. Med., 1917, xx, + 725. + +[Illustration: Fig. 44.--Upper curve. Record obtained during period of +cardiac syncopy at 2:48 p.m., Lead II. Lower curve from dog. Ventricular +fibrillation observed in the exposed heart. Lead from right foreleg and +left hind leg. (Courtesy of Dr. G. C. Robinson.)] + +Autopsy revealed chronic fibrous endocarditis of aortic and mitral +valves, arteriosclerosis, bilateral carcinoma of the ovaries, and signs +of general chronic passive congestion. + +It is possible that the syncopal attacks in this case were the result of +sclerosis of the vessels supplying the heart muscle although careful +microscopical examination did not throw much light on the ultimate +cause. + + +=Extrasystole= + +Whenever there is a dropped beat or an intermittent pulse one may be +sure that it is the result of an extrasystole. Such extrasystoles are +produced in the ventricle at some point other than the regular path of +conduction of impulses. The extrasystole may have its origin in either +the auricle or the ventricle. If there is auricular extrasystole it can +not usually be recognized except by graphic methods. (Fig. 45.) The +ventricular extrasystole on the contrary is commonly seen and readily +recognized. Most of those seen in the clinic have their origin in some +part of the ventricular wall. Their two characteristics are that they +occur too early and that they are followed by a pause longer than the +normal diastolic pause. (Fig. 46.) + +[Illustration: Fig. 45.--Electrocardiogram showing auricular +extrasystoles (P). (Courtesy of Dr. G. C. Robinson.)] + +[Illustration: Fig. 46.--Electrocardiogram showing ventricular +extrasystole. Heart rate 56-60 beats per minute. Note that diastolic +pause in which extrasystole occurs is practically equal to two normal +diastolic pauses. (Courtesy of Dr. G. C. Robinson.)] + +When one listens over the chest to a heart when extrasystoles are +occurring, one suddenly hears a weak beat which has taken place rather +too early after the previous systole to be strong enough to effect the +opening of the aortic valves. Consequently there is no pulse, the blood +does not move, and that beat is lost to the circulation. Moreover, when +the next regular stimulus comes from the s-a node it finds the ventricle +in a refractory condition, having just ceased a contraction, and it is +not until the next sinus impulse that the ventricle responds normally. +(Fig. 46.) + +Patients who have occasional extrasystoles will say that all of a sudden +the heart turns upside down in the chest. Sometimes there is slight +sharp twinge of pain. Patients are at times quite alarmed about their +condition. Provided there is no evidence of gross myocardial lesion, the +extrasystole itself is of no great significance. + +While many cases showing pathologic causes for extrasystoles have more +or less marked arteriosclerosis, there are other states in which no +arteriosclerosis is found where the extrasystole is present. + + +=Heart Block= + +As heart block occurs frequently in cases characterized by extensive +arteriosclerosis, a brief discussion of the essential features will be +given. It is, however, probable that arteriosclerosis is not the cause +of any of the cases of heart block directly, but it is only a result of +the same etiological conditions which produce the lesion or lesions +which result in heart block. We may define heart block as the condition +in which the auricles and ventricles beat independently of each other. +There may be delayed conduction (Fig. 47), partial (Fig. 48), or +complete heart block (Fig. 49). In the former there are ventricular +silences, during which the auricles beat two, three, four, five, even up +to nine times, with only one ventricular contraction. It is believed by +most physiologists that the essential factor in the production of heart +block is an interference in the conduction of impulses from the +auricles to the ventricles through the band of tissue known as the +auriculoventricular bundle. + +[Illustration: Fig. 47.--Electrocardiogram showing delayed conduction +(lengthening of P-R interval). These P-R intervals are quite regular. +When irregular there is apt to be extrasystole of ventricle or +occasional blocking of impulse going to ventricle. (Courtesy of Dr. G. +C. Robinson.)] + +[Illustration: Fig. 48.--Electrocardiogram showing partial heart-block +in the three leads. Note the variability of P-R interval calculated in +seconds in Lead II. (Courtesy of Dr. G. C. Robinson.)] + +[Illustration: Fig. 49.--Complete heart block. (Courtesy of Dr. G. C. +Robinson.)] + +The bundle of muscles described by His in 1905, connecting the auricles +and ventricles, has been definitely shown to be the path through which +impulses having their origin in the orifices of the great veins pass to +the ventricles. The situation and size of this bundle has been thus +described in man by Retzer: + +"When viewed from the left side, the bundle lies just above the muscular +septum of the ventricles and below the membranous septum. In some hearts +the muscular septum is so well developed that it envelops the bundle. It +is then difficult to find, but occasionally it can be seen directly by +means of transmitted light. From the left side the bundle can be +followed no farther posteriorly than the right fibrous trigone, for here +the connective tissue becomes so dense that it is difficult to dissect +it away. The impression is, therefore, received that this mass of +connective tissue forms the insertion of the bundle. The bundle may be +followed anteriorly until it becomes intimately mixed with the +musculature of the ventricles. + +"When viewed from the right side of the heart, the bundle can not be +seen, because it is covered by the mesial leaflet of the tricuspid +valve, whose line of attachment passes obliquely over the membranous +septum. Then, if the endocardium is removed from the posterior part of +the septum of the auricle up to the membranous septum, the posterior +part of the auriculoventricular bundle will be exposed. If, in addition, +the membranous septum be removed, the bundle may be traced from the +point to which it could be followed when viewed from the left side as it +passes posteriorly over the muscular septum. In the region of the +auriculoventricular junction it loses its compactness, the fibers +divide, and the bundle seems to fork. One branch passes into the +superficial part of the valve musculature which descends from the +auricles, and the other branch passes directly into the musculature of +the auricle. + +"Briefly, the auriculoventricular bundle runs posteriorly in the septum +of the ventricles about 10 mm. below the posterior leaflet of the aortic +semilunar valves; with a gentle curve it passes posteriorly just over +the upper edge of the muscular septum and sends its fibers into the +musculature of the right auricle and of the auricular valves. In the +heart of the adult the bundle is 18 mm. long, 2.5 mm. wide, and 1.5 mm. +thick." (Erlanger.) + +All normal impulses have their origin in the sino-auricular node at the +junction of the superior vena cava with the right auricle (Fig. 50). +From there the impulse travels in the wall of the auricle in the +interauricular septum to the node of Tawara or A-V node (Fig. 51), +thence through the bundle of His to be distributed to the fibers of the +right and left ventricles. This sequence is orderly and perfectly +regular. + +[Illustration: Fig. 50.--Showing alternating periods of sinus rhythm and +auriculoventricular rhythm. (After Eyster and Evans.)] + +[Illustration: Fig. 51.--Period of auriculoventricular or "nodal" rhythm +following exercise in sitting posture. (After Eyster and Evans.)] + +It has also been shown that the independent auricular and ventricular +rates vary somewhat, that of the auricle being in general faster than +that of the ventricle. A strip of mammalian ventricle placed outside of +the body in proper surroundings will begin to beat automatically at the +rate of about 40 beats a minute. Experimentally various grades of heart +block have been produced in the dog's heart by more or less compression +of the bundle at the A-V ring. The block may be partial, when two to +nine auricular beats occur to every one of the ventricle, up to +absolute complete block when the auricles and ventricles beat +independently of one another. + +In any stage of partial block, pressure on the vagus nerve in the neck +produces certain specific changes. (Fig. 52.) Robinson and Draper[13] +have found qualitative differences in the two vagi. The right vagus +sends most of its fibers to the s-a node (Fig. 53) and has a more +evident influence on the rate and force of the cardiac contractions. The +majority of fibers from the left vagus are distributed to the A-V node +so that its most evident action is upon the conductivity of the impulse. +Pressure then on the right vagus will have a tendency to slow the whole +heart. Pressure on the left vagus will have a tendency to prolong the +P-R interval until even complete block occurs. Even when the heart block +is complete, stimulation of the accelerator nerve, as a rule, increases +the rate of both auricles and ventricles. + +[Illustration: Fig. 52.--Influence of mechanical pressure on the right +vagus nerve. (After Eyster and Evans.)] + +[Illustration: Fig. 53.--Schematic distribution of right and left vagus. +(After Hart.)] + + [13] Jour. Exper. Med., 1911, xiv, 217. + +If the block is functional, depending upon some temporary +overstimulation of the vagus nerve, atropin, which paralyzes the endings +of the vagus, will naturally lift the block. If the block is due to some +actual lesion of the bundle of His, such as fibrosis, gumma, or other +lesion, then atropin will have no influence to terminate the block. In +this manner we are able to distinguish between functional and organic +heart block. + + + + +CHAPTER V + +BLOOD PRESSURE IN ITS CLINICAL APPLICATIONS + + +It is well to bear constantly in mind the point made over and over in +this work, that blood pressure is only one of many methods of acquiring +information. He who worships his sphygmomanometer as a thing apart and +infallible will sooner or later come to grief. Judgment must be used in +interpreting changes in blood pressure just as judgment is essential in +properly evaluating any instrumental help in diagnosis. One must not +forget the personal equation which enters into even accurate +instrumental recording in medicine and surgery. + +In this chapter there will be no attempt to quote largely from what +others have said or thought. Every one has his own opinion as to the +value of certain methods after he has worked with them for a long time. +The ideas here expressed, except in cases where no opportunity has +offered to make personal studies, are those gathered from personal +experience. + + +=Blood Pressure in Surgery= + +Careful estimation of the blood pressure in surgical cases has, at +times, great value. In all surgical diseases the most important fact to +know is not the systolic pressure, but the pulse pressure. If the pulse +pressure keeps within the range of normal, does not drop much below 30 +mm. in an adult, then so far as we can tell the circulation is being +carried on. When the systolic pressure is gradually falling and the +diastolic remains the same, the circulation is failing and unless the +pulse pressure can be established again the patient will die. Again we +see the value of the pulse pressure. + +All prolonged febrile diseases tend to produce a lowering of the blood +pressure picture. The diastolic does not fall to the same extent as the +systolic so that there is a pulse pressure smaller than normal. This is +to be expected from what we know of the general depression of the +circulation in fevers. The blood pressure reading is only a graphic +record of what we have long known, and enables us from day to day +accurately to measure the general circulation. + + +=Head Injuries= + +It was claimed that in fracture of the skull or in concussion much could +be gained by frequent estimations of the blood pressure. This seemed +probable in the light of experiments on compressing the brains of dogs +by the use of bags inserted through trephine openings (Cushing). In the +clinic, however, it has not been found of any material value. It has a +value in differentiating a simple fracture, let us say, from a case of +uremia which is picked up on the street with a bump on the head. There +the high pressure usually found would at once direct attention to the +kidneys and the newer methods of blood examination would at once settle +the question. Naturally uremics may also have skull fracture. There the +diagnosis would be complicated. A decompression done at once would be +indicated. If the skull fracture happened in a uremic, the decompression +would probably do no harm. In fact, there are some who advise +decompression for uremia. + + +=Shock and Hemorrhage= + +In shock the blood pressure picture is low but the pulse pressure drops +to abnormally low figures. It seems to me that the blood pressure +instrument has its greatest value in surgery in the warning it gives to +the operating surgeon in cases of impending shock. + +It is well known that the first effect of ether, the commonly used +anesthetic, is to raise the blood pressure and quicken the pulse rate. +The whole blood pressure picture is at first elevated (Fig. 54). Soon +the whole pressure falls slightly but continues at a higher level than +normal. The diastolic pressure drops back nearly to normal and the +increased pulse pressure is due almost entirely to the slight rise in +the systolic pressure. Now the whole duty of the anesthetist is to +administer the ether so that this ratio of systolic and diastolic is +maintained throughout the operation. Warning comes to him of impending +shock before it comes to any one in the neighborhood (Fig. 55). Any +sudden change in the pressure is a signal for increased watchfulness. +Should the pressure all at once drop he can immediately notify the +surgeon and institute measures to resuscitate the patient. + +[Illustration: Fig. 54.--Blood pressure record from a normal reaction to +ether. Note that the systolic and diastolic rise and fall together. At +the end of the anesthetization the pulse pressure is practically the +same as at the beginning. Compare this with the record in Fig. 55, where +the operation had to be discontinued on account of the onset of shock.] + +[Illustration: Fig. 55.--Beginning of operative shock. Chart showing the +method of recording blood pressure during operation. + +Note that the pulse and respiration show no remarkable changes, but the +blood pressure steadily fell, the systolic more than the diastolic so +that the pulse pressure was gradually reaching the danger point. Further +work on this case was stopped following the warning given by the blood +pressure. The patient was returned to the ward and a week later +anesthesia was again given, the operation was completed, and the patient +had a satisfactory convalescence.] + +A method which is widely used is as follows: The anesthetist wraps the +cuff of one of the dial instruments around the patient's arm, and +arranges the dial so that it can easily be seen by him at all times. +This does not in any way interfere with the work of the surgeon. Over +the brachial artery below the cuff is the bell of a binaural stethoscope +held in place by the strap attachment now on the market. The tubes of +the stethoscope are long enough to reach conveniently to the ear pieces. +A watch is pinned to the sheet of the table. He has a chart, as +illustrated (Fig. 56) on a board and makes a dot in every space for five +minute intervals. By joining the lines a curve is obtained which tells +at a glance what the circulation is doing. I feel sure that more +attention and care exercised on the part of the anesthetist would be the +means of conserving many lives lost from shock following operation. + +[Illustration: Fig. 56.--Showing method of using blood pressure +instrument during operation without interfering with the operator or +assistants. Sheet thrown back to show cuff on arm of patient. +Anesthetist has chart on table beside him, dial pinned to pad in full +view, bulb near hand. Extra tubing must be put on the blood pressure +instrument.] + +A sudden drop in the pressure picture may mean a large hemorrhage. The +gradual return of the pressure picture means that the vasomotor +mechanism has acted to keep up the pulse pressure. Should the diastolic +pressure continually fall, it may mean that the hemorrhage is still +taking place (Wiggers). + + +=Blood Pressure in Obstetrics= + +One might affirm almost without fear of contradiction that the constant +determination of blood pressure during pregnancy is more important than +the examination of the urine. Within recent years a number of observers +having access to a large material, have given the results of their +findings. There is a striking unanimity of opinion, although now and +then a difference in minor details. + +The blood pressure should be taken frequently during pregnancy. The +usual and highly essential precautions in taking pressure in general +apply most particularly in these cases. Towards the end of pregnancy the +pressure should if possible be taken daily and oftener if necessary. + +Pressure in women is usually below 120 mm. Many patients have a +temporary rise in blood pressure during pregnancy, due oftenest to +constipation, without developing other symptoms. This is common to all +conditions and has no significance. Some think that an abnormally low +pressure, that is, a systolic below 90 mm., suggests that the patient is +likely to react unduly to the strain of labor. This is denied by others. +Among 1000 cases (Irving) the pressure was below 90 in only one case. A +gradually rising pressure precedes albuminuria, as a rule. If there is +albumin without change in pressure the albumin may usually be +disregarded. Some think that a pressure over 130 mm. systolic should be +carefully watched. The danger limit is set by some at 150 mm. If the +blood pressure from the very first is high, it may mean only that that +was the patient's normal pressure. This calls for increased +watchfulness. It is held by some that high blood pressure favors +hemorrhage and probably explains the hemorrhagic lesions in the placenta +and some viscera in eclampsia and albuminuria. + +All are agreed that the most significant change is the gradual but sure +rise from a low pressure. When this is combined with albuminuria the +danger of toxemia is imminent. The high blood pressure in those under +thirty years of age seems to be a more certain sign of approaching +toxemia than the same pressure in those older. The pressure falls within +a few days to its normal after delivery in the toxic cases. + +Although the emesis gravidarum is held to be a sign of a toxemia of some +unknown nature, the blood pressure is never raised even in the +pernicious form. + + +=Infectious Diseases= + +In all infectious diseases the blood pressure tends to be lower than +normal. During chills the systolic may rise to great height due to the +violent muscular contractions. + +We found the blood pressure of great value in giving information +concerning the circulation. Again we repeat that it is not the systolic +alone or the diastolic alone but the pulse pressure which we wish to +keep informed about. In pneumonia we have tried out Gibson's law only to +discard it. This so-called law is that in pneumonia the systolic +pressure in millimeters should remain above the figure for the pulse +rate. When the figure in mm. of pressure is equalled by or exceeded by +the pulse rate the prognosis is grave. + +In typhoid fever we have made many estimations at various stages of the +disease. We can only say that the pressure picture tends to fall during +the course. The systolic falls more than the diastolic so that it is not +uncommon to see pulse pressures of 20 mm. at the beginning of +convalescence in spite of the high caloric feeding practiced. At the +time of perforation the systolic pressure may be raised. This is only +the reflex from the initial pain. Soon the pressure falls and if +peritonitis sets in, the pressure is exceedingly low and the pulse +pressure gradually falls until the circulation can no longer be carried +on. In large hemorrhage the pressure suddenly falls. If only one +hemorrhage has occurred a gradual rise takes place, but the general +pressure picture remains at a lower level for days, gradually returning +where it was before the hemorrhage. + +In beginning failure of the circulation we found elevation of the foot +of the bed about nine inches to be of such value that we felt there must +be some increase in blood pressure. Numerous readings were made covering +a period of several months. Although we felt certain that the +circulation was improved, we rarely needed cardiac stimulation, we never +could prove any increase of blood pressure with the sphygmomanometer. + +In all infectious diseases there is no help offered by blood pressure +estimations in diagnosis. The sole and important use is that of keeping +track of the circulation. + + +=Valvular Heart Disease= + +No rules can be laid down for blood pressure in valvular heart disease. +Aortic stenosis, the rarest of the valvular lesions, is practically +always accompanied by high pressure picture. Mitral stenosis on the +contrary usually shows a low pressure picture. Mitral insufficiency may +show an exceedingly low picture or an exceedingly high picture. Aortic +insufficiency also may be accompanied by a high systolic or by a normal +systolic pressure. It depends on the etiology. Practically all the +rheumatic cases have low pressure, the syphilitic cases have a high +pressure. It is characteristic of all cases of aortic insufficiency that +the diastolic pressure is low, even as low as 30 mm. The pulse pressure +is invariably high. Usually there is no difficulty in determining the +diastolic pressure. The intense third tone suddenly becomes dull at the +point of diastolic pressure and frequently the dull sound can be +distinctly heard over the artery down to the zero of the scale. If +difficulty is found in reading the diastolic as the pressure is reduced, +the estimation may be reversed and the pressure gradually increased from +zero to the point where the dull tone suddenly becomes loud and clear. +These points always coincide. + + +=Kidney Diseases= + +This has already been discussed somewhat fully in Chapter III and will +receive more consideration later. It might be remarked in passing that +in a case of seeming coma where albumin is found in the urine but where +the blood pressure is low or normal, I have found at autopsy in several +cases pyonephrosis and not chronic nephritis. The blood pressure may be +useful in differentiating uremic coma from the coma of pyonephrosis. +Also in the cases of coma with anasarca, either the acute, subacute or +chronic form the blood pressure is not raised as a rule. Other diseases +of the kidney, as tuberculosis, cancer, infection with pyogenic +organisms, are not accompanied with any notable changes in blood +pressure. + + +=Other Diseases, Liver, Spleen, Abdomen, etc.= + +Blood pressure is only of value in the above diseases in affording +information concerning the state of the circulation. There is nothing +characteristic about the pressure in any of these diseases. + + + + +CHAPTER VI + +ETIOLOGY + + +The causes of arteriosclerosis are many and varied. No two persons have +the same resisting power toward poisons that circulate in the blood. +Some go through life exposed to all the infectious diseases without ever +becoming infected, while others fall easy victims to every disease that +comes, no matter how careful they may be, and it is quite the same in +regard to the resistance of the arterial tissues. If the tubing is of +first class quality and the individual does not place too much strain on +it, he may live to the biblical three-score years and ten, and possess +arteries which have undergone such slight changes that they are not +palpable. Such a person is, however, the exception. On the other hand, +if the tissue is of poor quality, even the ordinary wear and tear of +life causes early changes in the vessels, and a person of forty may have +hard arteries. + +We have described in a previous chapter the changes which normally occur +in the arteries as age advances. An artery that is normal for a man of +fifty years would be distinctly abnormal for a boy of fifteen. + +Two broad divisions of arteriosclerosis may be made: (1) congenital, or +the result of inherited tendency; (2) acquired. + + +=Congenital Form= + +When Dr. O. W. Holmes was asked how to live to the age of seventy, he +replied that a man should begin to pick his ancestors one hundred years +before he was born. Our parents determine the character of the tissues +with which we start in life, and this determines our general resistance. +We might properly speak of congenital arteriosclerosis where the +affected individual had poor arterial tissue with which to begin life, +for that, in a sense, is a congenital defect, and arterial tissue that +is poor in quality is prone to disease. + +The author is more and more impressed with the part that heredity plays +in the determination of arterial degeneration. Especially does syphilis +in the parents or grandparents leave its stigma in the succeeding +generations in the shape of poor arterial tissue which is prone to early +degeneration. Recently W. W. Graves has called attention to a +malformation of the vertebral border of the scapula which consists in a +concavity instead of the normal convexity of the bone. To this +malformation he has given the name, scaphoid scapula. He considers this +to be but one manifestation of a general lack of development in the +individual. He speaks of this maldevelopment as a blight and considers +that syphilis in the ancestors is responsible for the condition in the +offspring. He finds that even in children, the subjects of the scaphoid +scapula, the arteries are very definitely thickened. While confirmation +of his observations is lacking, there is no doubt that we must lay the +blame for much of the arteriosclerosis in our patients to the poor +quality of arterial tissue transmitted by ancestors who have acquired +some constitutional disease. It may have been syphilis, it may have been +the degeneration produced by alcohol or other drug. We can not ignore +the part which heredity plays. The various factors to be considered in +the production of the acquired form of arteriosclerosis appear to me to +be but contributory factors to a very great extent, the essential and +fundamental factor being the quality of arterial tissue with which the +individual is endowed. + +Arteriosclerosis may occur in infants. Cases have been reported of +calcification of the arteries in infants and children. The +arteriosclerosis may occur without nephritis or rise of blood pressure. +Cerebral hemorrhage in a child of two years has been seen. Heredity in +these cases plays a most important role. In many of the reported cases +there was no question of congenital syphilis. Aneurysms, single or +multiple, have been found in the arteries of children, and even the +pulmonary artery may show sclerotic changes. + + +=Acquired Form= + +As a rule the cases usually seen belong in this group because it seems +as if a connection could be established almost always between one or +more of the etiologic factors to be described and the disease. While +this apparently is the case, we must never lose sight of the part which +the quality of the tissue plays. When we leave this out of our +calculations we undoubtedly make many false deductions. When two men of +the same age who have been exposed to the same conditions as far as we +can learn, are found to have quite different arteries, the one normal, +the other thickened, we must postulate congenitally poor tissue on the +part of the latter. Such tissue readily becomes diseased following +conditions which would very likely have produced no noticeable effect on +perfectly normal, healthy tissue. + + +=Hypertension= + +Hypertension must still be reckoned with in the etiology of +arteriosclerosis although the role that it was thought to play does not +seem so important. Changes of blood pressure alone are not considered by +many to be sufficient for the production of arteriosclerosis. This may +play some part, but there are many other factors mostly unknown which +determine in any case the production of arterial lesions. + +With every systole of the heart, blood is forced out into the arterial +system against a certain amount of resistance represented by the +tonicity of the capillary area, and the amount of cohesion between the +viscous blood and the walls of arterioles. When a dilatation of the +capillaries over any large area takes place, the blood pressure falls, +provided there is no compensatory contraction in other areas to make up +for the decreased resistance in the dilated vessels. The viscosity of +the blood, as such, probably has very little effect on the resistance to +the flow. With the systole of the heart there is a sudden dilatation of +the arch of the aorta, and a wave of expansion follows, which is +transmitted to the periphery and is lost only in the capillaries. + +The blood pressure is constantly changing. Physiologically there are +relatively wide variations in the pressure in a perfectly normal +individual. There are some persons who have hypotension, a blood +pressure much below the normal. Such persons have usually small hearts, +small aortas, and they seem to have but little resistance to disease. +Many diseases, especially the prolonged fevers, diminish markedly the +blood pressure. Whether the hypertension is the cause of the structural +changes that are found in the walls of the vessels, or is the result of +the diminished area of the arterial tree through which the same amount +of blood has to be driven as before the vessel walls became narrowed, is +still disputed. As has been stated, experimental evidence would tend to +place the initial blame upon the poisons circulating in the blood, which +first damage the vessel walls. The subsequent changes then produce +thickening and inelasticity. Some think (Allbutt) that the hypertension +is primary. There are cases seen clinically that lend support to this +view and there is experimental evidence also (v. Chap. II). Not +infrequently individuals in middle life begin to show increase of +arterial blood pressure without discoverable cause. In such case it may +be that there is slowly progressing chronic nephritis. The urine if +examined only superficially in single specimens may not reveal any +abnormalities. Careful functional examination by means of the newer +tests may reveal functional deficiency. It must not be supposed that +all cases of increasing hypertension are cases of chronic nephritis. The +opinion has already been expressed (Chap. III) concerning this point. +Experience has convinced me that the opinion expressed in former +editions is not altogether correct. + + +=Age= + +No age is exempt from the lesions of arteriosclerosis if we consider the +two groups. However, the disease is seen for the most part in persons +past middle life. The relative frequency with which it is found in the +different decades depends on so many factors that it is of no value to +tabulate them. As has been stated, arteriosclerosis of all types is an +involution process that advances with age. Longevity is a question of +the integrity of the arterial tissue, and no one can tell what sort of +"vital rubber" (Osler) any one of us has. However, many with poor tubing +may make such use of it that it will outlast good tubing that is badly +treated. Unfortunately we have no way of telling early enough with just +what sort of arterial tissue we are starting life. + + +=Sex= + +There is no doubt that men are far more prone to arterial disease than +women are; all statistics are in accord on this point. This is explained +by the greater exposure of men to those conditions of life which tend to +produce circulatory strain, and so to produce arteriosclerosis, or vice +versa. Arteriosclerosis in women is not often seen until after the +fiftieth year. Cases of the most extreme grade of pipe stem arteries +are, however, seen in old women, and calcified arteries are not hard to +find among the inmates of an old woman's home. + + +=Race= + +Some of the most beautiful examples of arteriosclerosis in this country +are seen in the negro. Not only is this disease more frequent in the +black race, but the age of onset is much earlier than in the Caucasian. +The accidents of arteriosclerosis, viz., aneurysm, cerebral hemorrhage, +etc., are more common among the negro males. The etiologic factors that +are most often found in the history are the prevalence of syphilis and +hard physical labor. + + +=Occupation= + +Certain occupations have a distinct causal relationship to +arteriosclerosis; among such are particularly those entailing prolonged +muscular exercise, especially if much lifting is necessary. Every one is +familiar with the phenomena accompanying the exertion of lifting. The +breath is drawn in, the glottis is closed, and the muscles of the chest +wall are held rigidly while the exertion lasts. This causes a great +increase in blood pressure, and constant repetition of this will produce +permanent high tension. In hospitals, the stevedores as a class have +marked arteriosclerosis, and, almost without exception, they are +comparatively young men. Occupations that are accompanied with prolonged +mental strain, such as now occur to the heads of large manufacturing and +financial institutions, also predispose to early arterial changes. +Psychic activity, especially when it is accompanied by worry, is a +potent factor in the production of the increased blood pressure which is +the chief factor in producing arterial disease. It has been suggested +that sexual continence in high-strung men produces changes in the +nervous system which can conceivably lead to the production of high +tension and further to arteriosclerosis. This, however, I can not think +has any foundation in fact except in so far as such men are prone to +live at high speed and wear themselves out sooner than the normal +person. The sexual continence _per se_ is not harmful. There are, +however, men who seem not to be harmed by the constant wear and tear of +our modern life. These are the exceptions. + +Workers in factories where paint is made and the ingredients +hand-mixed, are prone to develop arteriosclerosis early in life. It has +been found that the laborers most apt to be victims of lead intoxication +are those who are careless in their habits of cleanliness, particularly +in regard to the fingernails. The continuous absorption of lead into the +system, brings about a condition of hypertension that has its inevitable +results. + +The fact is that any occupation which entails either the absorption of +toxic substances, or prolonged muscular labor, will hasten markedly the +onset of arterial disease. + + +=Food Poisons= + +The opinion that arteriosclerosis is due in large part to poisoning by +end products or by-products of protein digestion is now receiving much +support. Experiments on dogs and rabbits have lent some confirmation to +chemical observations. It has been shown that dogs fed for a long time +on putrefied meat developed inflammation and degeneration of the +adventitia and media, with hyperplasia and calcification of the intima +of many arteries. In the pulmonary and carotid arteries, in the vena +cavas and myocardium, there were extensive necroses and hyaline +degeneration. Moreover, injections of sodium urate and ergot caused +necroses in the muscularis and elastica of the aorta, pulmonary artery, +vena cavas inferior and heart muscle, but there was no calcification. +Guinea pigs which were fed indol in small doses by the mouth over a long +period showed atheromatous degeneration of the aorta. + + +=Infectious Diseases= + +As more study has been given to the arteries in persons who have died of +the acute infectious diseases, more has come to light concerning the +effects of the toxins of these diseases on the vessel walls. In the +arteries of children who have died of measles, scarlet fever, +diphtheria, cerebrospinal meningitis, etc., degenerative changes in the +arteries occur, modified only by the length of time that the toxins have +acted. + +Thayer has shown that the arteries of those who have passed through an +attack of moderately severe or severe typhoid fever are as a rule more +readily palpable than are the vessels of persons of corresponding years +who have never had the disease. Clinically the typhoid toxin appears to +cause the early production of arteriosclerosis. The changes in the +arteries occur for the most part, and always earlier, in the peripheral +arteries, and the media is chiefly affected. Minute yellowish patches +are found on the aorta, carotids, and coronaries. In persons who have +passed through an attack of one of the fevers, and have later died from +some other cause, regenerative changes are sometimes found to have taken +place in the arteries, consisting of an ingrowth of elastic fibers from +the intact adventitia to the diseased media. + +That there are some other factors than the infectious disease which are +concerned in the production of arterial changes seems evident from a +study[14] made recently among a group of almshouse inmates ranging in +age from 38 to 90 years. The study included 500 persons of both sexes. +Careful histories were taken to determine the presence of antecedent +infectious disease. The radial artery was palpated to determine the +presence of sclerosis. Among the cases giving a history of one +infectious disease the following table gives the results: + + ------------------------------------------------------------- + DISEASE NO. + ++ +++ POSITIVE NEGATIVE + ------------------------------------------------------------- + Measles 47 10 6 12 28 19 + Infectious arthritis 38 9 6 4 19 19 + Pneumonia 30 5 8 5 18 12 + Typhoid 27 6 8 3 17 10 + Scarlet fever 10 0 0 4 4 6 + Smallpox 14 1 4 0 5 9 + Miscellaneous 12 2 5 2 9 3 + ------------------------------------------------------------- + 178 33 37 30 100 78 + ------------------------------------------------------------- + + [14] Warfield, L. M.: Jour. Lab. and Clin. Med., November, 1917. + +A summary of the cases showed: 252 cases without sclerosis; 248 with +sclerosis; 147 cases with infections but no sclerosis; 180 cases with +infections and sclerosis. + +This study failed to throw any positive light on the question. +Infectious diseases undoubtedly play a certain role, particularly those +continuing a long time and certain particular infectious diseases, as +measles. + + +=Syphilis= + +Syphilis is one of the most important of the etiologic factors in the +production of arteriosclerosis. It has been shown that in 85 per cent of +cases of aortic insufficiency in persons, usually males, over forty-five +years, who did not have chronic infective endocarditis, the Wassermann +reaction was positive. Acute aortitis affecting the ascending and +transverse portions of the arch of the aorta is very commonly seen, and +the irregular, scattered, slightly raised, yellowish-white patches of +sclerosis in the arch which are found years after the syphilitic lesion, +are considered by some to be very characteristic of syphilis. +Mesaortitis is the primary lesion and acts as a _locus minoris +resistentiae_ where an aneurysm forms. + +Hypertensive cardiovascular cases have been serologically studied, and a +positive Wassermann reaction found in a large percentage of one series. +In fifty cases, 90 per cent either gave a positive Wassermann reaction +or luetin test, were known to have syphilis, or had children with +hereditary syphilis. This suggests what might be called "familial +cardiovascular syphilis." + +Hypertensive disease is possibly one of the common so-called "late" +manifestations of syphilis. That syphilis is responsible for the +arterial disease in the vessels of the brain, resulting in apoplexy or +sudden cardiac death in middle life, has long been known. In fact, it is +claimed (Osler) that all aneurysms occurring in persons under thirty +years of age are due to syphilitic aortitis. In the late stages of +syphilis the arterial lesions may be of a diffuse character. + + +=Chronic Drug Intoxications= + +Lead, tobacco, and according to some, tea and coffee, are to be classed +as causal factors in the production of arteriosclerosis. Certain it is +that all these substances have a tendency to raise the arterial +pressure, but whether the drug itself causes first a degeneration, and +later a hypertension results, or vice versa, is not yet positively +known. We have just mentioned that lead particularly has a marked effect +in producing arterial lesions. Other drugs as adrenalin, barium +chloride, physostigmin, etc., while producing experimental +arteriosclerosis, hardly could produce the disease in man. =Alcohol= has +been blamed for much, and as an etiologic factor in the production of +arteriosclerosis formerly was accorded a first place. More recently much +doubt has been thrown on this supposition by the work of Cabot, who +showed that the mere drinking of even large quantities of spirits had no +effect in producing arterial disease. + +This observation has been recently substantiated by Hultgen, who +carefully studied clinically 460 cases of chronic alcoholism. He says, +"There are no cardiovascular symptoms which might be termed +characteristic of chronic alcoholism, unless it be the peculiar fetal +qualities of the heart sounds which we know as embryocardia. I find this +very frequent among drinkers, but I can offer only a tentative +explanation for it, namely the following: Embryocardia can only occur +with low tension blood pressure, and in the absence of renal +insufficiency. Hence it might be considered as a useful condition of no +pathologic significance at all. That alcohol is a sclerogenic pharmakon +and productive of arteriosclerosis with its usual train of symptoms may +be a fact, but its demonstration would be difficult and is really not +shown by my tabulations. There were cardiovascular changes, such as +myocarditis, aortitis, valvular heart disease and arteriosclerosis in +chronic alcoholics in 54.3 per cent of 461 cases, but this by no means +constitutes a proof of the causal relationship between these lesions and +the abuse of liquors. I believe it, nevertheless, to be good reasoning +to ascribe the bulk of cardiovascular symptoms to the sclerogenic action +of alcohol, while abstaining from an interpretation of its +pathogenesis." Just what role =tobacco= plays is difficult to say. My +own opinion is, that of itself when used in moderation, it has no ill +effects. However, as tobacco is a drug that may raise the blood +pressure, excessive use must be held responsible for the production of +arteriosclerosis. It is difficult to separate its effects from those +produced by eating and drinking. + + +=Overeating= + +There can be no doubt but that the constant overloading of the stomach +with rich or difficultly digestible food is responsible for a large +number of cases of arteriosclerosis. Every one must have noted the +increase in force and volume of the heart beat after the ingestion of a +large meal. The constant repetition of such processes conceivably can +lead to damage to the vessel walls through hypertension. + +In the metabolism of food in the intestines there are substances +produced which are poisonous when absorbed directly into the +circulation. Ordinarily these substances are rendered harmless either +before absorption or are detoxicated in the liver to harmless +substances. It is conceivable that a constant overproduction of such +poisons would eventually damage the defensive mechanism of the body to +such an extent that some of the poisons would circulate in the blood. An +expression of a surplus of one, at least, of these decomposition +products is the appearance of indican in the urine. It is not believed +that indicanuria has the importance attached to it which some authors +would have us believe. It is found too often and in too many varying +conditions, nevertheless it undoubtedly does reveal the presence of +perverted metabolism. + +In how far the toxins absorbed from the intestinal tract are responsible +for the production of arterial disease, it is not possible to say. Some +observers lay great stress on this factor as a cause of +arteriosclerosis. The author believes that the role played by the +absorption of products of perverted intestinal metabolism is an +important one. The primary change is an increased tension in the +arterioles which later leads to thickening of the coats of the vessels +and to the other consequences of arterial disease. A vicious circle is +thus established which has a tendency to become progressively worse. + + +=Mental Strain= + +More and more does one become impressed with the fact that patients with +arteriosclerosis are very often those who take life too seriously and +either from ambition or from an exalted sense of duty lead especially +strenuous lives. Not always are these persons addicted to drug or liquor +habit. Many are rather abstemious in their habits. It is not so often +that we see as a victim of arteriosclerosis, the carefree person who +laughs his way through life without worrying about the morrow. He is not +so prone to arteriosclerosis. Worry is a far more potent cause of +breakdown than actual manual work. It is the rule to find thickened +arteries among neurasthenics. This may be only part of a generalized +degeneration of all tissue in the body. The blood pressure in such +persons is usually low. So many men of our better class live under a +continuous mental strain in the business world. The increase in +arteriosclerosis cases is real, not apparent. The intense mental strain +seems to cause a marked increase in blood pressure (for short periods of +mental effort this has been proved) over a period of time sufficient to +cause permanent changes in the vessel walls. The same sequence of events +repeats itself; high tension, arterial strain, compensatory thickening, +hypertrophied heart, etc. + +Certainly the character of the arterial tissue has much to do with the +determination of degenerative changes which may result from the action +of one or more of the etiologic factors. + + +=Muscular Overwork= + +Muscular overwork is to be reckoned with as an etiologic factor. One +sees it especially among the laboring class in both whites and negroes. +Possibly other factors, as alcohol and coarse heavy food, contribute to +the early arterial degeneration. Hypertrophy of the heart occurs in +athletes, and statistics gathered among the oarsmen especially, show a +relatively high mortality at the different decades traceable to the high +tension produced while in training. This question deserves more +consideration than has been accorded it. + + +=Renal Disease= + +Chronic disease of the kidneys (contracted red kidney) is one of the +most certain producers of hypertension; in fact, some maintain that high +tension, even without demonstrable kidney lesions, as revealed by +careful urine examinations, is a valuable sign pointing to chronic +nephritis. This is doubted by others, myself among them. Just what +causes the increase in blood pressure sometimes to over 270 mm. of Hg, +is not definitely known. It seems most probable that it is some poison +elaborated by the diseased kidneys and absorbed into the general +circulation. There it acts primarily on the musculature of the +arterioles causing tonic contraction and an increase of work on the part +of the heart to force the blood through narrowed channels. One fact is +certain. We see patients in coma due to renal disease with blood +pressure much over 200 mm of Hg. As these cases clear up, the pressure +may fall, and should they seemingly recover, the recovery is accompanied +with a marked decrease in blood pressure, finally reaching the normal +for the individual. Moreover, in the course of a severe acute or +subacute nephritis, hypertension is associated with headache, partial or +total blindness, and drowsiness. When the pressure is reduced, all these +symptoms disappear. + +There is also the chronically shrunken and scarred kidney known +pathologically as the arteriosclerotic kidney. It is probable that there +are two groups of cases which we may designate: (1) primary; (2) +secondary. In the primary group the kidney disease antedates the +sclerosis of the arteries, and the sclerosis is most probably dependent +on the constant high tension. We know that prolonged hypertension will +produce severe forms of arteriosclerosis. The arterial disease in this +group is caused by the renal disease. + +In the second group the kidney changes are apparently due to the general +arteriosclerosis which, affecting the kidney vessels, causes changes +leading to atrophy and subsequent fibrous tissue ingrowth of scattered +areas. These cases are not necessarily associated with hypertension; on +the contrary there is more apt to be hypotension. Where the first group +occurs for the most part in young and active middle-aged people, the +second group is the result of involutionary processes which accompany +advanced age. + +However careful a urinalysis may be, there is no assurance that one can +predict the pathologic state of the kidney. Often so-called normal urine +will be secreted by a badly diseased kidney, whereas a urine which +contains considerable albumin and many casts may be secreted by a kidney +which is only temporarily the seat of inflammation. What matters after +all is not the state of the kidney which the pathologist describes, but +the actual functional response of the kidney in the body to the various +tests now well known. + + +=Ductless Glands= + +At the present time the tendency among some writers is to make the +ductless glands the responsible agents in almost all diseases. +Arteriosclerosis is no exception to this tendency. Sajous, for example, +divides the morbid process producing arteriosclerosis into three types; +(1) autolytic, (2) adrenal, (3) denutrition. In the first type he finds +the pancreas to be the most important gland. It supplies an internal +secretion which "takes a direct part in the protein metabolism of the +tissue cells, and also in the defensive reactions within these cells, as +well as in the phagocytes and in the blood stream." This being the case +exaggeration of this digestive process has tissue destruction as its +result, arteriosclerosis among them. + +In the adrenal type Sajous argues that adrenalin produces lesions +experimentally, therefore the adrenal gland has a profound influence by +its internal secretion in connection with the sympathetic system in +producing degenerations leading to arteriosclerosis. + +The denutrition type has as its particular gland the thyroid. The +sclerotic process in the arteries is due to the lack of thyroid as in +cases of myxedema. After a long resume of his ideas he concludes "that +arteriosclerosis is the result of excessive or deficient activity of +certain ductless glands, the thyroid and adrenal in particular." + +No one can dogmatically deny the part which the ductless glands may play +in the production of arteriosclerosis, but it hardly seems that there is +enough actual experimental evidence to show that they take such an +important part as Sajous believes. Until further and more convincing +evidence is offered by competent investigators, I prefer to look with +some skepticism upon the ductless gland theory of the causation of +arteriosclerosis. The field lends itself too easily to speculation and +imagery. Some are already allowing themselves the mental debauch of this +nature. + + + + +CHAPTER VII + +THE PHYSICAL EXAMINATION OF THE HEART AND ARTERIES + + +=Heart Boundaries= + +In order to be able to estimate the departures from normal in the +boundaries of the heart, it is essential that there be a definite +appreciation of the boundaries of the normal heart in relation to the +chest wall. + +It is frequently stated that the right limit of cardiac dullness is +normally, in the adult, just at the right border of the sternum. This is +not strictly accurate. Careful dissections at the autopsy table and +x-ray plates of the chest made at a distance of two meters from the tube +show that the border of the right auricle is from one to one and a half +and even two centimeters from the edge of the sternum at the level of +the fourth rib, and on the living subject this can be also demonstrated. +The right border of the heart usually is from 3 to 4 cm. from the +midsternal line at the level of the fourth rib. + +Again there is a term used in defining the apex, known as the point of +maximum impulse. As this does not always coincide with the apex beat and +with the outer lower left border of the heart, it would be better to use +the term apex beat. + +Normally, then, the cardiac dullness, the so-called relative cardiac +dullness, begins above at the upper border of the third costal +cartilage, as a rule, and taking a somewhat curved line with the +concavity inward, descends to the fifth interspace or beneath the fifth +rib from 9 to 10 cm. from a line drawn through the center of the sternum +parallel to its length, the midsternal line. This seems to me to be a +better method of recording the size of the heart than by the lines +commonly used; viz., the nipple, or midclavicular, or parasternal line. +Below, the cardiac dullness is merged into the tympany from the stomach +and the dullness from the liver. At the sixth right costosternal +articulation there is a sharp turn upwards forming at that point with +the liver the cardiohepatic angle. At the fourth right cartilage or the +third interspace, the dullness is from one to two centimeters from the +edge of the sternum. We have then a somewhat pear-shaped area or +triangular area with the apex at the apex of the heart. The so-called +absolute cardiac dullness does not appear to me to be of any great +significance. In reality it is the limit of lung resonance and may be +greater or less, not so much on account of variations in the size of the +heart, as of variations in size of the lungs and shape of the chest +wall. + +The really crucial question which should always be asked is, Is the +heart enlarged or decreased in size? The position of the apex beat alone +can not determine this, neither can the limit to the right of the +sternum. The distance between these two points and the depth of the +dullness at a distance of 5 cm. from the midsternal line on the left +side, will give the size of the heart as nearly as can be obtained in +the living subject. A series of measurements in normal adults average 13 +to 14 cm. and 9 to 10 cm. respectively. For women they are about 1 cm. +less in each direction. + +The elaborate mechanism known as the orthodiagraph is probably the best +means of determining the actual limits of the heart, but few men have +such an expensive instrument, and, moreover, at the bedside such an +instrument could not be used. From comparative measurements I concur in +the belief of those who affirm that careful percussion will furnish +equally as accurate limits. + +The first step in making an examination of the heart is to expose the +patient's chest in a good light, and, sitting at his right side, +carefully inspect the chest. The position of the apex beat, heaving, +bulging, retraction of interspaces, etc., can easily be seen if +visible. After careful inspection has given all the data which it is +possible to obtain, one next lays the palm of the hand over the heart +and attempts to palpate the apex beat. The thrust of the apex in a +hypertrophied heart can readily be felt, and one can feel whether the +heart is regular, irregular, intermittent, or has other change in +rhythm. The shock of the closing valves, particularly the aortic, can be +felt, and that and the forcible apical impulse are very suggestive signs +of hypertrophy and hypertension. Thrills may also be felt and can be +timed in relation to the heart cycle. + + +=Percussion= + +It is to percussion that we next proceed, and for the data in regard to +the size of the heart, it is, for our purpose, the most valuable of all +the physical methods of heart examination. + +First and foremost we wish by percussion to learn the actual size of the +heart, in other words what is ordinarily called the relative cardiac +dullness. With the absolute dullness we are not concerned. That +irregular area represents, as has been said, actually the =limits of +lung resonance=. The heart may or may not be covered with lung; there +may or may not be the incisura cardiaca. What I wish to insist upon is +that the size of the area of absolute dullness can give us no data in +regard to the size of the heart. What we must endeavor to learn is the +actual size of the heart as nearly as our crude means will permit. + +Light, very light, almost inaudible percussion, what Goldscheider called +"Schwellungsperkussion," must be practiced. Use the middle finger of the +right (left) hand as the hammer and the last joint of the middle finger +of the left (right) hand pressed firmly against the chest, as +pleximeter. I believe it is better to place the pleximeter finger +parallel to the boundary to be limited although some place the finger +perpendicularly, that is, pointing toward the boundary. Now and then it +helps to bend the pleximeter finger at the second joint, hold it +perpendicularly to the chest wall, and strike the joint directly in line +of the finger. This in my hands has been of great assistance in +percussing the limits of the heart dullness. Pottenger's "light touch +palpation" is a modification of the light palpation and, to my mind, has +no very special advantages. Auscultatory percussion is of great value at +times. The bell of the stethoscope is placed over the portion of heart +uncovered by lung (should such be the case), and with this point as a +center the chest is lightly and quickly tapped along radii converging +toward the stethoscope. One soon learns to recognize the change of pitch +as the tapping reaches the border of the heart. It is well to use all +methods, especially in difficult cases, and to compare the results. +Personally I have found that by light percussion I can limit with much +accuracy the upper, right, and left borders of the heart. + +There is much to be gained by using light percussion. Strong blows set +in vibration not only the underlying structures, but also more or less +of the chest wall. We wish to avoid this source of error, we do not wish +to differentiate by pitch alone. Finally one's pleximeter finger +becomes, after long practice, so sensitive to changes in the resonance +of structures lying below it, that there is actual feeling of impairment +to the slightest degree. This delicate touch is what we should endeavor +to cultivate. + +It is at times of advantage to use immediate percussion. This is done by +bending the fingers of the striking hand, bringing the tips in a line +and striking the chest lightly with the four fingers as one finger. Some +find it easier to percuss the dullness due to the heart in this way than +by mediate percussion. + +The little hammer and hard rubber, celluloid, bone, or ivory pleximeter +does not seem to me to be nearly as good as the fingers. Moreover, one +always has his hands, but may forget his hammer and pleximeter. + + +=Auscultation= + +In auscultating the heart I prefer the binaural stethoscope of the Ford +pattern. The recent substitution of an aluminum bell for the hard rubber +bell is an improvement. Personally I do not favor the phonendoscope or +any of the new patent non-roaring instruments now for sale by urgent +instrument makers. The phonendoscope has its uses, for example in +auscultating the back when a patient is lying in bed or in listening to +the heart sounds when a patient is under an anesthetic; but for +differentiating the murmurs and for heart diagnosis, I much prefer the +regular bell stethoscope. + +In arteriosclerosis the two places over which it is important to listen +are the apex and the second right cartilage, the aortic area. Over the +former, one gains data in regard to the strength of the heart as +indicated by the first sound, over the latter point, one learns of the +tension in the aorta by the character of the sound produced when the +aortic valves close. + +The hypertrophy of the heart in arteriosclerosis is invariably due to +the enlargement and thickening of the left ventricle. From the nature of +the position which the heart assumes in the thorax, this enlargement is +downward and to the left. The apex beat will therefore be found in the +fifth or sixth interspace, and definitely at an increased distance from +the midsternal line. As stated above, it is most important that this +distance be accurately measured and put down in the notes of the case +for future reference. No satisfactory prognosis can be given unless this +is done, for the gradual increase or the decrease under treatment in the +size of the heart can thus be definitely known, and, knowing the other +factors, a prognosis may be given which will be of some value to the +patient. + + +=The Examination of the Arteries= + +It is exceedingly difficult at times to affirm definitely that an +artery, the radial for example, is actually sclerosed. Much depends on +the sensitiveness of the fingers of him who palpates, and much upon the +relation of the palpated artery to the surrounding, chiefly underlying, +structures. In the examination of arteries it is well to inspect the +body for the pulsations caused by them. Frequently an exceedingly +tortuous artery, such as the brachial, may be seen throughout its whole +extent and yet the radial appear little, if any, thickened by palpation. +Again the artery of a pulse of high tension which is small in size but +full between the beats, may not be as sclerosed as one which collapses +and feels much softer. It is difficult to obtain accurate data in regard +to the tension in an artery by feeling it with the fingers of one hand. +One should use both hands. With the middle finger of the right (left) +hand the artery is compressed peripherally, that is, nearest the wrist. +The blood is then pressed out of the artery with the middle finger of +the left (right) hand, so as to obliterate completely the pulse wave and +the two or three inches between the middle fingers are felt with the +index fingers. By holding the finger firmly on the artery near the wrist +so as to block any wave that may come through the palmar arch by +anastomosis with the ulnar artery and by releasing pressure on the +proximal middle finger, some idea may be had of the degree of pulse +tension. However, no amount of practice can more than approximate the +tension and when one is surest that he can tell how many millimeters of +pressure there are, he is apt to be farthest wrong when he checks his +guess with the sphygmomanometer. + +Much may be learned from carefully palpating the peripheral arteries, +and, as a rule, the sclerosis of these arteries means general +arteriosclerosis, although there are many exceptions to this. + +A more recent method, and one which in the author's hands has been found +to be valuable, is that proposed by Wertheim-Salomonson who palpates the +artery not with the ball of the finger but with the fingernail. The +finger is held so that the nail is perpendicular to the surface of the +skin and the artery is felt with the end of the nail. The sensation is +perceived at the root and makes use of all the sensitive nerve endings +there. In this way it is possible to feel the arterial wall distinctly, +and a little practice will enable one to determine whether or not the +vessel wall is thickened. It is also possible to determine with a +considerable degree of accuracy the diameter of the artery and the size +of the wall when the current is cut off by pressure on the proximal side +of the artery. It is best to have a firm background when this +"fingernail" palpation is used. This may be obtained by palpating the +radial artery against the lower end of the radius. + +Probably the best method of palpating the arteries, especially the +radial, to determine the degree of sclerosis and thickening, is to use +the tip of the finger and roll it carefully over the artery. The tip of +the finger is exceedingly sensitive and, moreover, it is a firmer +palpating surface than the ball, thus enabling one to appreciate degrees +of sclerosis which could not be differentiated by palpation with the +soft yielding ball. This finger tip palpation is well illustrated in the +figures here shown. (Figs. 57 and 58.) + +[Illustration: Fig. 57.--A method of finger-tip palpation of the radial +artery. (Graves.)] + +[Illustration: Fig. 58.--Another method of finger-tip palpation of the +radial artery. (Graves.)] + + +=Estimation of Blood Pressure= + +It must be borne in mind at the outset that arteriosclerosis and high +blood pressure are not always associated. As a matter of fact in the +severest grades of senile arteriosclerosis the blood pressure is usually +below the normal for the individual's years. However, as high tension is +a frequent factor in the production of arterial thickening, blood +pressure readings are of importance. + +The instrument which one uses is of minor importance provided it is +properly standardized. The most important feature of the instrument is +the cuff. This must be 12 cm. wide and be long enough to wrap around the +arm several times so that the pressure is evenly distributed over the +whole arm and not over a small portion. One mercury instrument we had in +the hospital was reported to be at great variance with a dial +instrument. This mercury instrument was provided with a cuff which was +short and was tied around the arm by means of a piece of tape. This +caused a tight constriction over a small area and rendered the +estimation too high. A new, long tailed cuff easily remedied the +apparent defect in the instrument. + +In taking blood pressures the difference from day to day of 10 or even +15 mm. of systolic pressure has no great significance. Fluctuations of +the systolic pressure alone, it is insisted upon, have very little +meaning. One must take the whole pressure picture into consideration and +determine how the picture changes in order to draw any conclusion in +regard to the state of the blood pressure. Failure to pay attention to +this evident point has caused much futile work to be written and +published. + +It is well to emphasize again the point that the blood pressure picture +consists of the systolic, the diastolic, the pulse pressure and the +pulse rate. + + +=Palpation= + +Hoover has called attention to the direct palpation of the femoral +artery just below Poupart's ligament as a more accurate index of the +pressure in the aorta than the palpation of the radial artery. Possibly +one can obtain a more accurate estimate of the blood pressure in this +way. This, however, is open to dispute. To estimate the blood pressure +by palpating the radial artery is most deceptive. In about 75 per cent +of cases one can tell fairly well whether the pressure is abnormally +high or abnormally low. Small variations are impossible to determine. +Unquestionably it is most advantageous to get into the habit of +palpating the femoral artery and checking the result with the +sphygmomanometer so that the fingers may be trained to appreciate as +accurately as possible changes of pressure. + +It may be that one day when the instrument is needed it is not at hand. +A well-trained touch then becomes a great asset. + + +=Precautions When Estimating Blood Pressure= + +There are certain precautions which must be strictly observed when +deductions are drawn from the manometer readings. The psychic factor +must be reckoned with. Any emotion may cause marked variations in the +pressure. Excitement and anger are especial sources of error. Even the +slight excitement arising from taking the first blood pressure on a +nervous patient especially is apt to give false values. Usually the +readings must be taken many times at the first sitting and the first few +may have to be set aside. Worry is a potent factor in raising the +pressure. A walk to the physician's office, especially if rapid, has its +effect. + +The position of the patient when the blood pressure is taken is +important. Usually in the office the pressure is taken when the patient +sits in a chair. He should assume a relaxed, comfortable attitude. The +readings should be made at the same time of day and at the same interval +between meals. The pressure in both arms should be measured and +comparisons should be made only between readings on the same arm. These +precautions may seem useless and even somewhat trivial, and the +conditions difficult to control. But unless they are carefully observed +the readings will be false, no comparisons can be drawn between the +readings on different days, and the instrument will most probably be +blamed. I have known this to happen so often that I can not emphasize +too strongly the importance of controlling all the essential conditions +which go to make accurate work. + + +=The Value of Blood Pressure= + +In the past few years there has been a veritable avalanche of blood +pressure instrument salesmen who have covered the country, sold +instruments, and have made many startling claims for the instrument. +They have emphasized its value out of proportion to what the instrument +can do even in the hands of one familiar will all the defects. +Consequently it is not necessary to emphasize the value of blood +pressure. It seems best to utter a few words of caution in regard to its +interpretation. + +The value lies not in the occasional estimation compared with some other +one reading, but in the frequent estimation and in the visualization of +the blood pressure picture. For the great majority of diseases the blood +pressure has no particular value except to show that the circulation is +not materially disturbed. The limits of normal are rather wide, so that +consideration of the patient's age, sex, build, etc., will give us some +idea of a base line, so to speak, for any one person. Wide departures +from relatively normal figures are important, but are not diagnostic or, +rather, pathognomonic. I can not help but feel that the diastolic +pressure is _the_ most important part of the blood pressure picture. +Persistent high diastolic pressure means increased work for the heart, +which, if acting for a long time against the high peripheral resistance, +must eventually hypertrophy. The arteries become thickened, lose their +wonderful elasticity, fibrous tissue is deposited in their walls, and +the vicious circle is established which leads to pathologic +hypertension. + +Blood pressure readings must be intimately mixed with brains in order to +be of any great value in diagnosis or prognosis. + + + + +CHAPTER VIII + +SYMPTOMS AND PHYSICAL SIGNS + + +=General= + +Well developed arteriosclerosis shows four pathognomonic signs: (1) +hypertrophy of the heart; (2) accentuation of the aortic second sound; +(3) palpable thickening of the arteries; and (4) heightened blood +pressure. However, it must not be inferred that these signs must be +present in order to diagnose arteriosclerosis. It has already been said +that a very marked degree of thickening, with even calcification of the +palpable arteries, may occur with absolutely no increase of blood +pressure, and at autopsy a small flabby heart may be found. + +While arteriosclerosis is usually a disease which is of slow maturation, +nevertheless cases are occasionally seen which develop rather rapidly. +The peripheral arteries have been noticed to become stiff and hard in as +relatively brief a time as two years from the recognized onset of the +disease. + +Since involution processes are physiologic, as has been described (vide +infra), arteriosclerosis may assume an advanced grade and run its course +devoid of symptoms referable to diseased arteries. It is doubtful +whether the sclerosis itself could produce symptoms, except in cases +later to be described, were it not that the organs supplied by the +diseased arteries suffer from an insufficient blood supply and the +symptoms then become a part of the symptom-complex of any or all the +affected organs. + +There are cases, however, in comparatively young persons where a +combination of certain ill-defined symptoms gives a clue to the +underlying pathologic processes. These symptoms of early +arteriosclerosis are the result of slight and variable disturbances in +the circulation of the various organs. Normally there are frequent +changes in the blood pressure in the organs, but the vasomotor control +of normal elastic vessels is so perfect that no symptoms are noted by +the individual. When the arteries are sclerosed, they are less elastic +and the blood supply is, therefore, less easily regulated. At times +symptoms occur only after effort. The patient may tire more readily than +he should for a given amount of mental or bodily exercise; he is weary +and depressed, and occasionally there is noted an unusual intolerance of +alcohol or tobacco. Vertigo is common, especially on rising in the +morning or in suddenly changing from a sitting to a standing position. +Some complain of constant roaring or ringing in the ears. There may be +dull headache that the accurate fitting of glasses does not alleviate. +Unusual irritability or somnolency with a disinclination to commence a +new task may be present. Sometimes the effort of concentrating the +attention is sufficient to increase the headache. This has been called +"the sign of the painful thought." Numbness and tingling in the hands, +feet, arms, or legs are also complained of, and neuralgias, not +following the course of the nerves but of the arteries, also occur. It +is important to remember that the train of symptoms resembling +neurasthenia in a person over forty-five years old may be due to +incipient arteriosclerosis. This tardy neurasthenia frequently +accompanies cancer, tuberculosis, diabetes, and incipient general +paralysis, as well as incipient arteriosclerosis. + +Bleeding from the nose, epistaxis, taking place frequently in a +middle-aged person, sometimes is an early symptom. The bleeding may be +profuse, but is rarely so large as to be positively harmful. In fact, it +may do much good in relieving tension. Slight edema of the ankles and +legs is seen. Dyspnea on slight exertion is not uncommon. Dyspeptic +symptoms are not infrequent, pyrosis (heartburn), a feeling of fullness +after meals with belching or a feeling of weight in the epigastrium. +The dyspeptic symptoms may be so marked that one might almost speak of a +variety of arteriosclerosis, the dyspeptic type. For quite a while +before any symptoms that would definitely fix the case as one of +undoubted arteriosclerosis, the patient complains that foods which +previously were digested with no difficulty now give him gastric +distress. The examination of the stomach contents of a patient +presenting gastric symptoms reveals usually a subacidity. The total +acidity measured after the Ewald test meal may be only 20 and the free +HCl may be absent. Attention has been called to an unnatural pallor of +the face in early arteriosclerosis. Progressive emaciation is sometimes +seen in cases of arteriosclerosis and may be the only symptom of which +the patient complains. + + +=Hypertension= + +Not all cases of arteriosclerosis are accompanied by increased arterial +tension. As has been stated in a previous chapter, the blood pressure in +the arterial system depends chiefly on two factors; viz., the degree of +peripheral (capillary) resistance, and the force of the ventricular +contraction. The highest arterial pressures recorded with the +sphygmomanometer occur not in pure arteriosclerosis but in cases where +there is concomitant chronic interstitial disease of the kidneys. When +this is found there is always arteriosclerosis more or less marked. In +cases where the arteries are so sclerosed that they feel like pipe stems +there may be an actual decrease in the blood pressure. Hence the +clinical measuring of the pressure in the brachial artery alone is not +sufficient for a diagnosis of arteriosclerosis. A persistent high blood +pressure even with normal urinary findings is not a sign of +arteriosclerosis. The high tension later may lead to the production of +sclerosis of the arteries, but in these cases the kidney may be +primarily at fault. + +The impression must not be gained that hypertension in itself always +constitutes a disease or even a symptom of disease. Hypertension itself +is practically always a compensatory process. That is to say, it is the +attempt on the part of the body to equalize the distribution of blood in +the body when there is some poison causing constriction of the small +arteries. In this sense hypertension is not only essential, but actually +life-saving. A heart which is so diseased that it can not respond to the +call for increased action by hypertrophy of its fibers, would shortly +wear out. The very fact that the heart becomes enlarged and the tension +in the arteries becomes high, indicates that in such a heart there was +great reserve power. But while hypertension is largely an effort at +adjustment among the various parts of the circulation, it nevertheless +tends to increase, provided the cause or causes which produced it act +continuously. Moreover, as has been said (Chap. II), the arterioles do +not respond to increased work on the part of the heart by expanding, but +by contracting. A vicious circle is thus maintained which eventually +must lead to serious consequences. + +Hypertension is then, if anything, only a symptom which may or may not +demand treatment. That hypertension leads to the production of sclerosis +of the arteries has been repeatedly affirmed here. In certain cases it +is good and should not be experimented with. In other cases it is bad +and some treatment to reduce the tension must be tried. The main point +is to regard hypertension as one regards a compensated heart lesion. + +Prof. T. Clifford Allbutt divides the causes of arteriosclerosis +clinically into three classes: (1) The toxic class--the results of +poisons of the most part of extrinsic origin, chiefly those of certain +infections. In some of these diseases, the blood pressures, as for +example, in syphilis, are ordinarily unaffected; in others, as in lead +poisoning, they are raised. (2) The class he calls hyperpietic,[15] in +which an arteriosclerosis is the consequence of tensile strength, of +excessive arterial blood pressure persisting for some years. A +considerable example of this class is the arteriosclerosis of granular +kidney, but in many cases kidney disease is, clinically speaking, +absent. (3) The involutionary class, in which the change depends upon a +senile, or quasisenile degradation. This may be no more than wear and +tear, a disposition of all or of certain tissues to premature +failure--partly atrophic, partly mechanical--under ordinary stresses; or +it also may be toxic, a slow poisoning by the "faltering rheums of age." +In ordinary cases of this class the blood pressures for the age of the +patient are not excessive. Although the toxins of the specific fevers, +notably typhoid, as stated above, and influenza, have been shown to +produce arteriosclerosis, this, under favorable circumstances he +believes tends to disappear. This has been shown by Wiesel. + + [15] From pieso to squeeze, oppress or distress. Hyperpiesis, + therefore, signifies excessive pressure. + +As the blood pressure is dependent on the resistance offered by the +capillaries and arterioles, there are only two ways in which increased +pressure can be brought about; either by rendering the blood more +viscous, or by the generation of some poison from the food taken into +the body which, acting on the vasomotor center or directly on the finer +vessels, arteriolar or capillary, sets up a constriction over any large +area, and mainly in the splanchnic area. In regard to the liability to +arteriosclerosis, this area stands second only to the aortic and +coronary areas. He believes that arteriosclerosis itself has little +effect in raising arterial pressure. Many cases are seen in which with +extreme arteriosclerosis there was no rise in blood pressure, and some +in which pressures have been rising even long before the appearance of +arterial disease. Prof. Allbutt also believes that in the hyperpietic +cases the arteries undergo a transient thickening, which can be removed +if the causes can be reached and overcome. + +Clinically speaking, then, hyperpietic arteriosclerosis is not a +disease, but a mechanical result of disease. If the narrowing of the +arterioles is brought about by thickening due to arteriosclerosis, then +it would seem _a priori_ that such obliteration should cause a rise in +pressure. Were the vascular system a mere mechanical set of tubes and a +pump, this would happen, but other factors of great importance must be +taken into consideration besides the mechanical factors; viz., chemical +and biological factors. Thus, whole parts may be closed and with +compensatory dilatation in other parts there would be little or no +change in pressure, unless there were hyperpiesis. In established +hyperpiesis, we note two conditions in the radial artery: first, a +comparatively straight vessel with a small diameter; secondly, a larger, +more tortuous vessel, "the large leathery artery." In the cases of the +first group, hyperpiesis is often more marked, although not appearing so +to the examining finger, than in the second class. In view of the +difficulty of estimating by touch alone the amount of hyperpiesis in a +contracted hard artery, it is often overlooked until a ruptured vessel +in the brain startles us to a realization of our mistake. The "narrow" +artery is more dangerous than the tortuous one, for with every change in +pressure the passive vessels of the brain must receive blood that under +normal conditions would go to other parts of the circulation. + +In involutionary sclerosis there is a gradual thickening and tortuosity +of the vessel, which although it may be greater than in the hyperpietic +cases, yet is never so dangerous to life. The heart in hyperpiesis +hypertrophies and dilates, but such a heart is the result, not an +integral part, of the arterial disease. + + +=The Heart= + +When the arterial tree becomes narrowed and the resistance offered to +the flow of blood thereby is increased, more muscular work is required +of the left ventricle and according to the general laws which govern +muscles the ventricle hypertrophies. There is an actual increase in +number of fibers as well as an increase in the size of the individual +fibers. Some of the best examples of simple hypertrophy of the left +ventricle are found under such circumstances. The chambers as a rule do +not dilate until the resistance becomes greater than the contraction can +overcome, when symptoms of broken compensation of the heart take place. +The hypertrophy of the left ventricle brings more of this portion of the +heart toward the anterior chest wall. The enlargement is toward the +left, also, consequently the apex-beat is found below and to the left of +its usual site, even an inch or more beyond the nipple line. The impulse +is heaving, pushing the palpating hand forcibly up from the chest wall. +The visible area of pulsation may occupy three interspaces and the +precordium is seen to heave with every systole. On auscultation the +second sound at the aortic cartilage is ringing, clear, and accentuated. +Not infrequently, too, the first sound is loud and booming, but has a +curious muffled sound that may even be of a murmurish quality. The +leaflets of the mitral valve may be the seat of sclerosis, the edges are +slightly thickened and do not quite approximate, thus causing a definite +murmur with every systole. This murmur may be transmitted out into the +axilla and be heard at the inferior angle of the left scapula. + + +=Palpable Arteries= + +Not every artery that can be felt is the subject of arteriosclerosis, +and, as has been stated, palpable arteries being more or less a +condition of advancing years, judgment as to whether the artery is +pathologically or physiologically thickened may be a matter of +individual opinion. A radial artery that lies close to the lower end of +the radius and can actually be seen to pulsate when the hand is held +slightly extended on the back of the wrist, is easily felt, but must +not, therefore, be considered a sclerosed artery. The radial may be so +deeply situated in the wrist of a fat subject that it is difficultly +palpable. Yet the two cases just described may have arteries of +identical structure, there being no more retrogressive changes in the +one than in the other. "Experience is fallacious and judgment +difficult." + +The small, contracted, wiry artery of a chronic nephritic may feel like +a pipe stem, but if properly felt the mistake will not be made of +considering such an artery an unusually sclerosed one. When the wave is +pressed out of such a high tension artery, it is found that what seemed +to be a firm sclerosed vessel, was in reality an artery tightly +stretched over the column of blood. + + +=Ocular Signs and Symptoms= + +It would not exaggerate too much to say that the examination of the eye +grounds with the ophthalmoscope is the most important aid in the early +diagnosis of arteriosclerosis. Long before there are any subjective +symptoms, changes can be seen in the blood vessels of the retina which, +while not always diagnostic, at least call attention to a beginning +chronic disease. As I become more proficient in the use of the +ophthalmoscope, I am impressed with the importance of the ocular signs +of arterial disease. I would urge practitioners to familiarize +themselves with this instrument. The electrically lighted instruments on +the market now have so simplified the technic that any physician should +be able to see the grosser changes which take place in the arteries and +veins of the retina and in the disc. Frequently the ophthalmologist is +the first to recognize early arteriosclerosis. In the fundus are seen +increased tortuosity of the retinal vessels and their terminal twigs +with more or less bending of the vessels at their crossings. The +arteries are terminal ones, and small patches of retinitis are therefore +found. The changes have been divided into (1) suggestive, (2) +pathognomonic. + +Under (1) are: + +(a) Uneven caliber of the vessels, + +(b) Undue tortuosity, + +(c) Increased distinctness of the central light streak, + +(d) An unusually light color of the breadth of the artery. + +Under (2) are: + +(a) Changes in size and breadth of the retinal arteries so that they +look beaded, + +(b) Distinct loss of translucency, + +(c) Alternate contractions and dilatations in the veins, + +(d) Most important of all, the indentation of the veins by the stiffened +arteries. + +There is yet another sign which appears to be pathognomonic. The +arteries are pale, appear rigid and through the center, parallel to the +course, is a rather bright, fine threadlike line. The appearance is +known as the "silverwire" artery. It is particularly constant in +hypertension where the most beautiful examples are seen. + +Moreover, there is the arcus senilis, the fine translucent to opaque +circle surrounding the outer portion of the iris. Practically every one +with a well-marked arcus senilis has arteriosclerosis, but vice versa +not every one with even marked arteriosclerosis has an arcus senilis. + +In general, the symptoms are gradual loss of acute vision, and attacks +of transient loss of vision. The explanation which has been offered for +these phenomena is the contraction in a diseased central artery. + + +=Nervous Symptoms= + +The onset of arteriosclerosis is, in the majority of cases, so insidious +that certain nervous manifestations, due in all probability to +disturbances in blood pressure, are present long before the actual +sclerosis of the arteries can be felt. These nervous symptoms are at +times the sign posts to show us the way to accurate diagnosis. There may +be gradual increase in irritability of temper, inability to sleep, +vertigo even extending to transient attacks of unconsciousness. Loss of +memory for details frequently is an early symptom of sclerosis of the +cerebral arteries. Nervous indigestion may be present. Various +paresthesias as numbness, tingling, a sense of coldness or of heat or +burning, a sense of stiffness or even actual stiffness or weakness may +occur in the arms and legs, more frequently in the legs. The pain +complained of may be due to occlusion of an artery, although evidence +for this is lacking. It has been thought by some that the pain in angina +pectoris might be due to this cause. + +Several curious and interesting diseases which have been thought by some +to have arteriosclerosis as a basis are accompanied by pain. Such are +erythromelalgia, Raynaud's disease, "dead fingers," and intermittent +claudication. + +Erb has reported a large series of intermittent limp (claudication) from +his private practice. He finds that the large majority of the cases +occur in men. The abuse of tobacco was evidently the main etiologic +factor in about half of the cases. Repeated exposure to cold and the +abuse of alcohol were responsible for most of the other cases. Curiously +enough he finds that a history of syphilis was present in only a small +proportion of his cases. It is his firm conviction that intermittent +limping--which he thinks should be called angiosclerotic dysbasia--is +frequently incorrectly diagnosed. It is mistaken for other troubles and +treated wrongly. As gangrene may develop this is particularly dangerous. +The affection generally develops gradually, although he has seen cases +where the onset was rather acute. The partial or complete lack of the +pulse in the foot is the one striking sign, together with the varying +behavior of the pulse, its disappearance when the feet are cold and its +return after a warm foot bath or under other treatment. Signs of general +arteriosclerosis were present in nearly every case. When there is a +tendency to the development of intermittent limp he finds that a +valuable sign is the manner in which the leg blanches when it is lifted +repeatedly while the patient is recumbent and becomes hyperemic later +when placed horizontally. In health this change occurs more rapidly. + + + + +CHAPTER IX + +SYMPTOMS AND PHYSICAL SIGNS + + +=Special= + +Our conception of arteriosclerosis as a degenerative process affecting +the vascular tree rather than a disease, removes the possibility of +discussing special symptoms. As a matter of fact, we know of very few +organs where even profound pathologic changes in the vascular system +produced during life any symptoms which could be laid to these arterial +changes. Kind nature has given to us such an excess of organs of every +kind that the destruction of large portions of any organ seems to affect +the function but little. So only particular groups of organs, which show +symptomatic changes as the result of arteriosclerotic processes, will be +discussed. It is realized that this may not give Teutonic completeness +to the discussion, but it certainly saves paper and has a distinct +practical value to the long suffering reader. + +Although arteriosclerosis is a disease which affects the whole arterial +system, it nevertheless never reaches the same grade all over the body. +The difference in the structure and functions of the various organs +determines to great extent the eventual symptomatology. Endarteritis +obliterans of a small sized artery in the liver or leg would lead to no +marked symptoms, as the circulation is so rich that the anastomoses of +the blood vessels would soon establish a collateral circulation that +would be perfectly competent to sustain the function of the part. Quite +different would it be should one of the small arteries of the brain, the +lenticulo-striate, for example, which supplies the corpus striatum, +become the seat of a thrombosis or embolism caused by arteriosclerosis. +The arteries of the brain are terminal arteries and the blood supply +would be cut off entirely with a resulting anemic necrosis of the part +supplied by the artery and a loss of function of the part. What would be +of no moment in the leg or arm might prove even fatal in the brain. + +The further symptomatology, therefore, of arteriosclerosis depends +entirely on the organ or organs most affected by the interference with +the blood supply. The following groups may be recognized: + + 1. Cardiac. + + 2. Renal. + + 3. Abdominal. + + 4. Cerebral. + + 5. Spinal. + + 6. Local vasomotor effects. + + 7. Pulmonary. + + +=Cardiac= + +Most cases of arteriosclerosis sooner or later present symptoms +referable to the heart. When the organ is hypertrophied and is already +working against an enormous peripheral resistance, a slight excess of +work put upon it may cause a dilatation of the chambers with the +resulting broken compensation. There is dyspnea on slight exertion, +possibly some precordial distress, slight edema of the ankles and lower +legs and possibly scanty urine. With proper care, a patient with such +symptoms may recover, but the danger of another break in compensation is +enhanced. The next attack is more severe. The edema is greater, there +may be signs of edema of the lungs, effusions into the serous cavities +may occur. The heart shows marked dilatation. There is gallop or canter +rhythm and there are loud murmurs at the apex. When a patient is first +seen in this stage, it may be quite impossible to state whether or not +there is true valvular disease of the heart. The muscle is usually +diseased in that there is fibroid degeneration of more or less +extensive character. This factor causes the heart to lose much of its +elasticity and increases the tendency to permanent dilatation. Such +cases must be watched before one can say that true valvular +insufficiency is not present. The fatal termination of such a case is +quite like that of true valvular disease. There is increasing dyspnea, +increasing anasarca, and the patient usually succumbs to edema of the +lungs, drowned in his own secretions. + +[Illustration: Fig. 59.--Aneurysm of the heart wall. (Milwaukee County +Hospital.)] + +A very rare complication of the fibroid degeneration of the heart muscle +is aneurysm of the heart wall. (Fig. 59.) The apex of the left +ventricle is most commonly the site of the aneurysm and rupture +occasionally occurs. Such an accident is rapidly fatal. In the +arteriosclerotic process which occurs at the root of the aorta, the +coronary arteries become involved both at the openings and along the +courses of the vessels. A branch or branches or even one artery may +become blocked as a result of obliterating endarteritis. The arteries of +the heart are not terminal vessels but as a rule blocking of a large +branch leads to anemic infarct. These areas become replaced by fibrous +tissue which in the gross specimen appears as streaks of whitish or +yellowish color in the musculature. Anemic infarcts may not occur. In +such cases the anastomosis between branches of the coronary arteries is +unusually free. Through arteriosclerosis of the coronary vessels +extensive fibrous changes may occur that lead to a myocardial +insufficiency with its attending symptoms--dyspnea, irregular and +intermittent heart, gallop rhythm, edema, etc. One of the most +distressing and dangerous results of sclerosis of the coronary arteries +and of the root of the aorta is angina pectoris. While in almost every +case of angina pectoris there is disease of the coronary arteries, the +contrary does not hold true, for most extensive disease, even embolism, +of the arteries is frequently found in persons who never suffered any +attacks of pain. This symptom group is more common in males than in +females and as a rule occurs only in adult life. "In men under +thirty-five syphilitic aortitis is an important factor." (Osler.) + +Since the valuable experiments of Erlanger on heart block, considerable +attention has been paid to lesions of the Y-shaped bundle of fibers, a +bundle arising at the auriculoventricular node and extending to the two +ventricles, known also as the auriculoventricular bundle of His. +Interference with the transmission of impulses through this bundle gives +rise to the symptom group known as the Stokes-Adams syndrome, which is +characterized by: (a) slow pulse, (b) cerebral attacks--vertigo, +syncope, transient apoplectiform and epileptiform seizures, (c) visible +auricular impulses in the veins of the neck. Many of the cases which +occur are in elderly people the subjects of arteriosclerosis. + +[Illustration: Fig. 60.--Large aneurysm of the aorta eroding the +sternum. Death from rupture through the skin preceded by frequent small +hemorrhages. (Milwaukee County Hospital.)] + +So far as we now know all cases of the Stokes-Adams syndrome are caused +by heart block which is only another name for disease in the +auriculoventricular bundle. Of interest here is the fact that besides +gummata, ulcers, and other lesions of the bundle, definite +arteriosclerotic changes have been found. + +"The investigation of a typical case of Stokes-Adams disease has shown +that the symptoms of this case are caused by some lesion in the heart +which gives rise to the condition now generally termed heart block. +Practically all degrees of heart block have been observed, namely, +complete heart block and partial block with 4:1, 3:1, and 2:1 rhythm, +and occasionally ventricular silences. These stages occurred during +recovery. + +"Experiments testing the reaction of the heart to various extrinsic +influences demonstrate that when the block is complete the ventricles do +not respond to influences presumably of vagus origin, although the +auricles still respond normally to such influences, that effects exerted +upon the heart presumably through the accelerators still influence the +rate of the ventricles as well as that of the auricles. + +"When the block is partial the rate of the ventricular contraction +varies proportionally with the rate of the auricular contractions but +only within certain limits. When these limits are exceeded the block +becomes more complete, i. e., a 2:1 rhythm may be changed into a 3:1 +rhythm, this into a 4:1 rhythm, and this into complete block, and vice +versa. + +"The syncopal attacks are, in all probability, directly dependent upon a +marked reduction of the ventricular rate. Such reductions of the +ventricular rate are always associated with an increase of the auricular +rate, and it is believed that the latter is the cause of the former." +(Erlanger.) + +The epileptiform seizures of the syndrome may be caused by the anemia of +the brain resulting from failure of the heart to supply a sufficient +quantity of blood. + +The apoplectiform attacks are most probably caused by venous congestion +when the slowing of the ventricular contractions is not sufficient to +cause convulsions, but will just cause complete unconsciousness. + + +=Renal= + +Chronic nephritis, hypertension, arteriosclerosis form a most important +trinity. Some stoutly affirm that in all cases of high tension there is +chronic renal disease. Certainly the very highest blood pressures which +we see occur in the chronic interstitial forms of kidney disease. The +cause is most probably to be sought in some poison which is elaborated +in the kidney, is absorbed into the circulation and acts powerfully +either on the vasoconstrictor center as a stimulus, or directly on the +musculature of the small arteries all over the body. Usually +hypertension is progressive but it may be temporary. + +A man, 43 years old, entered the Milwaukee County Hospital in uremic +coma. The systolic blood pressure was 280-290 mm. Hg, the diastolic +pressure 220 mm. (Janeway instrument). Under treatment his blood +pressure gradually became lower, at the same period the albumin and +casts gradually disappeared from the urine. In two weeks from admission +he seemed perfectly well, there were no albumin or casts found in the +urine, and the systolic blood pressure was 136 mm., not a high figure +for a muscular man of the laboring class. It must be admitted, however, +that such cases are the exception, not the rule. + +Patients suffering from the association of chronic nephritis with +hypertension die slowly, usually. There is gradual development of +anasarca. Headache is frequent and severe. Pains all over the body may +occur. The sight may suddenly become dim or may even be lost. Dizziness +may be complained of and dyspnea is usually marked. Cyanosis comes on, +the pulse becomes weak, irregular or intermittent, heart failure sets +in, and the patient dies with edema of the lungs. + +Another class of renal arteriosclerosis is characterized by a small +granular kidney in which fibrous changes of a patchy character have +taken place. These scattered areas are the result of obliterating +endarteritis of renal arteries here and there with consequent anemia, +death of cells, and replacement by fibrous tissue. It occurs as part of +a generalized arteriosclerosis in which the whole arterial system is the +seat of diffuse (senile) sclerosis. The palpable arteries are usually +beaded or even encircled with calcareous deposits and the aorta is the +seat of an extensive nodular and ulcerating sclerosis. The heart is +usually small, shows extensive fibrous and fatty changes and possibly +the condition known as "brown atrophy;" the blood pressure is low. Such +cases do not show any special symptoms. They are anemic, short of breath +on exertion, have the appearance and show the signs of senility. + +In the first group it is, at times, difficult to say whether the kidney +disease or the arterial disease is the most important. From a clinical +standpoint the decision is not essential as the end results are much the +same in both. However, when actual uremic symptoms dominate the picture, +it becomes evident that the disease of the kidney is the chief feature +in the causation of the symptoms. + + +=Abdominal or Visceral= + +There is an important group of cases to which but little attention has +been paid until quite recently. This is the abdominal or visceral type +of arteriosclerosis. It has been stated that arteriosclerosis of the +splanchnic vessels almost invariably causes high tension. Among others, +Janeway has shown that general arteriosclerosis without marked disease +of the splanchnic vessels does not cause as a rule increase of blood +pressure. + +There are cases in which the brunt of the lesion falls upon the +abdominal vessels. Such cases have been called "angina abdominalis." It +has been suggested (Harlow Brooks) that this type of arteriosclerosis +may be determined by constant overloading of the stomach with food, +especially rich and spiced food. This causes overwork of the special +arteries connected with digestion and so leads to sclerosis of the +vessels of the stomach, pancreas, and intestines. Personal habits +probably influence to great extent the production of this more or less +=localized= condition. + +The organs supplied by the diseased arteries suffer from changes +analogous to those occurring in general or local malnutrition, such as +starvation, old age, or local anemias. These changes are atrophy with +hemachromatosis (brown atrophy) or fatty infiltration and degeneration. +Following the degenerative changes there result connective tissue growth +and further limitation of the functionating power of the affected +organs. + +Pain is a more or less constant symptom of visceral sclerosis. In the +early stages there may be only a sense of oppression, of weight, or of +actual pressure in the abdomen or pit of the stomach. There may be only +recurring attacks of violent abdominal pain accompanied by vomiting. In +some cases symptoms of tenderness in the epigastrium, pains in the +stomach after eating, vomiting and backache may suggest gastric ulcer. +There may be dyspnea and a sense of anguish accompanied with a rapid and +feeble pulse. Hematemesis may make the symptom group even more like +ulcer of the stomach, and only the course of the disease with the +failure of rigid ulcer treatment and the substitution of treatment +directed toward relief of the arterial spasm with resulting betterment, +enables one to make a diagnosis. The condition may be present for years +and the symptoms only epigastric tenderness with dizziness and sweating +on lying down after dinner, as in one of Perutz's patients. The attacks +are probably due to spasmodic contraction of the sclerosed intestinal +vessels with a resulting local rise in blood pressure. The pains are +most probably due to the spasm of the intestinal muscles, and some think +they are located in the sympathetic and mesenteric plexuses. + +This result of arteriosclerosis is not so uncommon, and by keeping this +cause of obscure abdominal pain in mind we are now and then enabled to +save a patient from operation. + +An autopsy on a case which for many years had attacks of abdominal pain +and cramp-like attacks, with high blood pressure and heart hypertrophy, +showed extensive sclerosis of the abdominal aorta, superior mesenteric +and iliacs. These vessels were calcified. Hypertrophy of the left +ventricle was found. The kidneys were microscopically normal. There were +no changes in the ascending aorta but in the descending portion there +were scattered nodules and small calcified plaques. + +The attacks of pain from which this patient suffered for many years, the +hypertrophy of the left ventricle and the increased blood pressure were +thought to be directly due to the sclerosis of the abdominal vessels. + + +=Cerebral= + +It has been stated that arteriosclerosis is a general disease, yet +certain systems of vessels may be affected far more than others, and +indeed there may be marked sclerosis at one part of the body and none +demonstrable at another part. + +In advanced sclerosis there may be one or more of a series of accidents +due to embolism, thrombosis, or rupture of the vessels. Such conditions +as transient hemiplegia, monoplegia or aphasia may occur. The attacks +may come on suddenly and be over in a few minutes; what Allbutt calls +"Larval apoplexies." They may last from a few hours up to a day, and are +very characteristic. A patient aged 64 years with pipe stem radials and +tortuous hard temporals would be lying quietly in bed when suddenly he +would stiffen, the eyes would become fixed and the breathing cease. In a +few seconds consciousness returned, the patient would shake himself, +pass his hand over his brow and ask, "Where am I? Oh, yes, that's all +right." He had as many as thirty of these attacks in twenty-four hours, +none of them lasting over one minute. To just what such attacks are due, +it is hard to say. Some have attributed them to spasm of the smaller +blood vessels of the brain, but there have never been demonstrated in +the vessels any constrictor fibers. + +There is a well recognized form of dementia caused by arteriosclerosis. +In general paralysis of the insane and in senile dementia the blood +vessels are always diseased. Milder grades of psychic disturbances are +accompanied by such symptoms as mental fatigue, persistent headaches, +vertigo, memory weakness and fainting. Aphasia, periods of excitement +and mental confusion occur in some. Later stages are at times +accompanied by inclination to fabulate, loss of judgment, +disorientation, narrowing of the external interests, episodes of +confusion and hallucinatory delirium. + +The hemiplegias, monoplegias and paraplegias may occur again and again +and last for one or two days. Unless there has been rupture of the +vessels, there is complete recovery as a rule. + +In persons who have arteriosclerosis with high tension attacks of +melancholia are seen. There are at the same time fits of depression, +insomnia, irritability, fretfulness, and a generally marked change in +disposition. When the tension is reduced by appropriate treatment these +symptoms disappear, to recur when the tension again becomes high. On the +contrary, attacks of mania are accompanied by low blood pressure. The +dizziness and vertigo in cerebral arteriosclerosis are probably due to +the stiffness of the vessels which prevents them from following closely +the variations of pressure produced by position, and thus, at times, the +brain is deprived of blood and a transient anemia occurs. + +Arteriosclerosis of the cerebral vessels is always a serious condition. +The greatest danger is from rupture of a blood vessel. Another of the +dangers is gradual occlusion of the arteries bringing about necrosis +with softening of the brain substance. The latter is more apt to be +associated with psychic changes, dementia, etc.; the former, with +hemiplegia. It is curious that a small branch of the Sylvian artery, the +lenticulo-striate, which supplies the corpus striatum, should be the one +which most frequently ruptures. Where the motor fibers from the whole +cortex are gathered together in one compact bundle, a very small +hemorrhage may and does cause very serious effects. A comparatively +large hemorrhage in the silent area of the brain may cause few or no +symptoms. + + +=Spinal= + +It is conceivable that arteriosclerosis of the vessels of the spinal +cord might cause symptoms which would be referred to the areas of the +cord where the process was most advanced. The lesions would be scattered +and consequently the symptoms might be protean in character. + +True epileptic convulsions dependent on arteriosclerotic changes are +also seen and are not so uncommon. + +This is on the whole a rare condition, much less common than +arteriosclerosis of the cerebral vessels. Collins and Zabriskie report +the following typical case: + + "H., a fireman, fifty-one years old, was in ordinary good health + until toward the end of 1902. At that time he noticed that his legs + were growing weak and that they tired easily. Later he complained of + a jerking sensation in different parts of the lower extremities and + at times of sharp pain, which might last from several minutes to two + or three hours. The legs were the seat of a heavy, unwieldy + sensation, but there was no numbness or other paresthesia. About the + same time he began to have difficulty in holding the urine, a + symptom which steadily increased in severity. These symptoms + continued until March, 1903, i. e., for three months, then he + awakened one morning to find that he was unable to stand or walk, + and the sphincters of the bowels and bladder relaxed. There was no + complaint of pain in the back or legs, no difficulty in moving the + arms, in swallowing or in speaking. He says he was able to tell when + his lower extremities were touched and he could feel the bed and + clothes. He was admitted to the City Hospital three weeks later and + the following record was made on April 21, 1903. + + "The patient was a frail, emaciated man of medium height, who had + the appearance of being 55-60 years of age. He was unable to stand + or walk. When he was lying, he could flex the thigh and the legs + slowly and feebly. There was slight atrophy of the anterior and + inner muscles, more of the left than of the right side. The knee + jerks and ankle jerks were absent. Irritation of the soles caused + quite a typical Babinski phenomenon. The patient had fair strength + in the upper extremities, but the arms tired very soon, he said. The + grip was moderate and alike in each hand. The motility of the face, + head, and neck was not noticeably impaired. There was no difficulty + in swallowing, and articulation was not defective. Tactile + sensibility was slightly disordered in the lower extremities, + although he could feel contact of the finger, the point of a pin, + and the like. Sensibility was not so acute as normal; there was a + quantitative diminution. Sensory perception was not delayed. There + was a distinct zone of slight hyperesthesia about as wide as the + hand above the femoral trochanters. Above that, sensibility was + normal. There was no discernible impairment of thermal sensibility. + No part of the body was particularly tender on pressure. A bedsore + existed over the sacrum, and there was excoriation of the genitals + from constant dribbling of urine. + + "Examination of the chest showed shallow respiratory movements. The + heart was regular, weak, there were no murmurs, the second sound was + accentuated. Examination of the abdomen showed that the liver and + spleen were palpable, but were not enlarged. The abdominal reflexes, + both upper and lower, were sluggish. The patient was slow of speech, + likewise apparently of thought. He did not seem to show an adequate + interest in his condition, still he was fully oriented and seemed to + have a fair memory. His mental reflex was slow. There were + indications in the peripheral blood vessels and heart of a moderate + degree of general arteriosclerosis. The peripheral vessels such as + the radial, were palpable, the walls thickened, the blood pressure + increased. + + "The patient did not complain of pain while he was in the hospital, + a period of four weeks, nor was there any particular change in the + patient's symptoms, subjective and objective, during this time. His + mental state remained clear until forty-eight hours before death, + when he became sleepy, stuporous, and comatose, dying apparently of + cardiac weakness, which had set in simultaneously with the clouding + of consciousness." + + At autopsy, except for a few small hemorrhages in the posterior + horns of the lower dorsal segments on the right side and a similar + condition of the left anterior horns, there was nothing noticed. On + microscopic examination, there was found widespread sclerosis of the + vessels of the cord to a marked degree with only slight thickening + of the vessels of the brain. There were secondary degenerations of + ascending and descending type particularly marked at the ninth + dorsal segment. They included portions of all the tracts, the + pyramidal tract as well. The symptoms in brief were: (1) weakness + and easily induced fatigue of the legs; (2) peculiar sensations in + the lower extremities, described as jerky, numbness, heaviness, and + occasionally sharp pain; (3) progressive incontinence of urine; (4) + progressive paraplegia. + +Since one of the chief manifestations of syphilis is sclerosis of the +arteries, neurologic cases characterized by irregular symptoms and signs +which can not be placed in any of the definite system disease groups, +are possibly due to irregularly scattered areas of sclerosis throughout +the spinal cord caused by obliterating arteritis. Such cases are not so +very uncommon. Several have come under my observation. Further studies +of the spinal cords of these cases at autopsy are necessary before a +final opinion can be given as to their dependence on arteriosclerosis of +the spinal vessels. + + +=Local or Peripheral= + +When the arteriosclerosis in the peripheral arteries reaches a stage +where endarteritis obliterans supervenes, there is usually no chance for +a compensatory or collateral circulation to be established. The area +supplied by the vessel undergoes dry gangrene. A portion of a toe or +finger or a whole foot or hand may shrivel up. It is more common to see +the spontaneous amputation take place in the lower extremities. The same +effect may be produced by the plugging of a vessel with a thrombus. +There may be much pain connected with the sudden blocking, whereas the +gradual obliteration of the blood supply of a toe or foot is not as a +rule at all painful. The condition is at times revealed more or less +accidentally when a patient injures his toe or foot and discovers that +there is no sensation in the part and that the wound instead of healing +is inclined to grow larger. + +Other interesting vasomotor phenomena are frequently connected with +arteriosclerosis. Such a one is the curious condition known as Raynaud's +disease, a vascular disorder which is divided into three grades of +intensity: (1) local syncope, (2) local asphyxia, (3) local or +symmetrical gangrene. This is not the place to describe this condition +except to say that the condition called "dead fingers" is the most +characteristic feature of the first stage. Chilblains represent the +mildest grade of the second stage. The parts are intensely congested and +there may be excruciating pain. Any one who has ever had chilblains +knows how painful they can be. The general health is not impaired as a +rule, although the attacks are apt to come on when the person is run +down. The third stage may vary from a very mild grade, with only small +necrotic areas at the tips of the fingers, to extensive multiple +gangrene. + +Another and very rare condition in which chronic endarteritis was the +only constant finding is the disease described by S. Weir Mitchell and +called by him erythromelalgia (red neuralgia). This is "A chronic +disease in which a part or parts--usually one or more extremities--suffer +with pain, flushing, and local fever, made far worse if the parts hang +down." (Weir Mitchell.) + +Probably the most frequently seen result of arteriosclerosis in the leg +arteries is the remarkable condition, first described by Charcot, known +as intermittent claudication. Persons the subject of this disease are +able to walk if they go slowly. If, however, any attempt be made to +hurry the step, there results total disability accompanied at times by +considerable cramp-like pain. The condition is much more prone to occur +in men than in women, and Hebrews seem more frequently affected. The +cause is most probably to be sought in the anemia which results from the +narrowing of the channels through which the blood reaches the part. The +stiff, much narrowed arteries allow sufficient blood to pass along for +the nutrition of the part at rest or in quiet motion. Just as soon as +more violent exercise is taken, calling for more blood, an ischemia of +the part supervenes, for the stiff vessels can not accommodate +themselves to changes in the necessary vascularity of the part. A rest +brings about a gradual return of blood and the function of the part is +restored. Pulsation may be totally absent in the dorsal arteries of the +feet and when the legs are allowed to hang down there is apt to be deep +congestion. + +In this connection a curious case reported by Parkes Weber will not be +out of place. The patient, a male, aged 42 years, complained of +cramp-like pains in the sole of the left foot and calf of the leg +occurring after walking for a few minutes and obliging him to rest +frequently. When the legs were allowed to hang over the side of the bed, +the distal portion of the left foot became red and congested looking. +No pulsation could be felt in the dorsal artery of the left foot or in +the posterior tibial artery. There was no evidence of cardiovascular or +other disease. An ulcer on the little toe had slowly healed, but +cramp-like muscular pains still occurred on walking. The disease had +lasted about five years without the appearance of gangrene. + +Weber calls this case one of arteritis obliterans with intermittent +claudication. + + +=Pulmonary Artery= + +In the symptomatology of sclerosis of the pulmonary artery the clinical +signs and symptoms are mostly referable to the obliterating endarteritis +of the smaller vessels, while the physical signs are more apt to reveal +the involvement of the main trunk. A history of severe infection in the +past is frequent, especially smallpox, and accompanying aortic sclerosis +with insufficiency of the mitral valve or stenosis of this valve is the +rule. Striking cyanosis is an early symptom, while there is little if +any dyspnea and edema. Intermittent dyspragia is common. There seems to +be no tendency to clubbed fingers. Repeated hemorrhages from the lungs +without the formation of infarcts may occur. There is usually an area of +dullness at the upper left margin of the sternum and nearby parts, +sensitive to pressure and to percussion, and the heart dullness extends +unusually far towards the right. The diagnosis of the right ventricular +hypertrophy may be substantiated by a fluoroscopic examination. + + + + +CHAPTER X + +DIAGNOSIS + + +=Early Diagnosis= + +Arteriosclerosis is essentially a disease of middle life and old age. It +is not unusual, however, to find evidences of the disease in persons in +the third decade and even in the second decade. Hereditary influences +play a most important role, syphilis and the abuse of alcohol in the +family history are particularly momentous. The recognition of the early +changes in the arteries among young persons depends largely upon how +carefully these changes are looked for. The difference in the point of +view of one man who finds many cases in the comparatively young, and +another man who rarely finds such changes early in life, at times, +depends upon the acuity of perception and observation and not upon the +fact that one man has had a series of unusually young arteriosclerotic +subjects. The diagnosis of arteriosclerosis may be so easily made that +the tyro could not fail to make it. It is, however, the purpose of this +volume to lay stress on the earliest possible diagnosis and, if +possible, to point out how the diagnosis may be arrived at. It is +obviously much to the advantage of the patient to know that certain +changes are beginning in his arteries, which, if allowed to go on, will +inevitably lead to one or more of the symptom groups described in the +preceding chapters. + +The combination of (1) hypertrophied heart, (2) increased blood +pressure, (3) palpable arteries, and (4) ringing, accentuated second +sound at the aortic cartilage is, in reality, the picture of advanced +arteriosclerosis. If the individual is in good condition much may be +done by judicious advice and treatment to ward off complications and +prolong life with a considerable degree of comfort. But we should not +wait until such signs are found before making a diagnosis and +instituting treatment. As in all forms of chronic disease the early +diagnosis is all important. + +The history of the case is the first essential. Often a careful inquiry +into the personal habits of a patient, with the record of all the +preceding infectious diseases will give us valuable information and may +be the means of directing the attention at once to the possible true +condition. Particularly must we inquire into the family history of gout +and rheumatism. An individual who comes of gouty stock is certainly more +prone to arterial degeneration than one who can show a healthy heredity. +Alcoholism in the family also is of importance because of the fact that +the children of alcoholics start in life with a poor quality of tissue, +and conditions that would not affect a man from healthy stock might +cause early degeneration of arterial tissue in one of bad ancestry. + +What infectious diseases has the patient had? Even the exanthemata may +cause degenerations in the arteries, but, as has been shown, such +lesions probably heal completely with no resulting damage to the vessel. +Should the patient have passed through a long siege of typhoid fever the +problem is quite different. Here (vide supra) (Thayer), the palpable +arteries do appear to be sclerosed permanently. Probably the length of +time that the toxin has had a chance to act determines the permanent +damage to the vessel wall. More potent than all other diseases to cause +early arteriosclerosis is syphilis, and hence very careful inquiry +should be made in regard to the possibility of infection with this +virus. Not only the fact of actual infection but the duration and +thoroughness of treatment are important matters for the physician to +know. + +What is the patient's occupation? Has he been an athlete, particularly +an oarsman? Has he been under any severe, prolonged, mental strain? Is +he a laborer? If so, in what form of manual labor is he engaged? Such +questions as these should never be overlooked, as they form the +foundation stones of an accurate diagnosis, and early, accurate +diagnosis, we repeat, is essential to successful therapy. + +We have called attention to the factor of sustained high pressure in the +production of arteriosclerosis. Constant overstretching of the vessels +leads to efforts of the body to increase the strength of the part or +parts. The material which is used to strengthen the weakened walls has a +higher elastic resistance than muscle and elastic tissue, but a lower +limit of elasticity, and is none other than the familiar connective +tissue. In athletes, laborers, brain workers who are under constant +mental strain, and in those whose calling brings them into contact with +such poisons as lead, there is every factor necessary for the production +of high tension and consequently of arteriosclerosis. + +Another question in regard to personal habits is how much tobacco does +the patient use and in what form does he use it? Our experience is that +the cigar smoker is more prone to present the symptoms of +arteriosclerosis than the cigarette smoker, the pipe smoker, or the one +who chews the tobacco. A very irritable heart results not infrequently +from cigarette smoking but such is almost always found in young men in +whom the lesions of arteriosclerosis are exceedingly rare. The +probabilities are that the arteriosclerosis in cigar smoking results +from the slowly acting poison which causes a rapid heart rate with an +increase of pressure. + +Last but not least, and perhaps the most important question is, has the +patient been a heavy eater? This I believe to be a potent cause of +splanchnic arteriosclerosis with the resulting indigestion, cramp-like +attacks, high blood pressure, etc. In a joking manner we are accustomed +to remark, "Overeating is the curse of the American people." There is, +however, much truth in that sentence. Osler, than whom there is no +keener observer, states that he is more and more impressed with the fact +that overloading the stomach with rich or heavy or spiced foods is today +one of the first causes of arterial degeneration. It stands to reason +that this is true. We know that organs exposed constantly to hard work +undergo hypertrophy, and that the blood tension in those organs is high. +Blood tension is, after all, dependent on capillary resistance, and if +the capillaries are distended with blood, the resistance is great. The +digestive organs can be no exception to this rule. Increased work means +an increase of blood. This inevitably causes distension of the +capillaries with stretching of the arteries and consequent damage to the +walls. Once arteriosclerosis is present a vicious circle is established. + +A man about forty-five consults us and says that he has noticed recently +that he gets out of breath easily; in tying his shoes he experiences +some dizziness. He finds that he has palpitation of the heart and +possibly pain over the precordial region now and then. He notices also +that he is irritable, that is, his family tell him he is, and he notices +that things that formerly did not annoy him, now are almost hateful to +him. On examination, one finds a palpable radial, a somewhat +hypertrophied heart and slightly accentuated second aortic sound. The +blood pressure may be high. The urine may or may not reveal any +abnormalities. Not infrequently, although no albumin may be found, there +are hyaline casts. Such a case of arteriosclerosis is evidently not to +be regarded as early. Then the question arises, How are we to recognize +early arteriosclerosis? I do not believe that the solution of this +problem lies entirely in the hands of the physician. Some men are +fortunate enough to come up for an examination for life insurance before +an observant doctor who recognizes the palpable artery, makes out the +beginning heart hypertrophy and the slightly accentuated second aortic +sound. The patient will tell you that he never felt better in his life. +He gets up at seven, works all day, plays golf, drinks his three to six +whiskies, and is proud of his physical development. But the great mass +of people are not fortunate from this standpoint. They do not seek the +advice of the physician until they are stretched out in bed. They boast +of the fact that for twenty years they have never had a doctor. One may +well say that it is a problem how to reach such persons. It seems to me +that there can be but one way to do this. The people must be taught that +the duty of a physician is just as much to keep them in health as it is +to bring them back to health when they are ill. To that end people +should be taught that at least twice a year they should be carefully +examined. I do not mean that the patient should present himself to the +doctor and, after a few questions the doctor say cheerfully, "You are +all right." The patient should be systematically examined. That means a +removal of the clothing and examination on the bare skin. Such +cooperation on the part of patient and doctor would save the patient +years of active life and make of the doctor, what his position entitles +him to be, the benefactor to the community. Too often careless work on +the physician's part lulls the patient into a false sense of security +and he wakes up too late to find that he has wasted months or years of +life. Early diagnosis of arteriosclerosis is only possible in +exceptional cases unless people present themselves to the physician with +the thought in mind that he is the guardian of health as well as the +healer. + +There are patients who go to the ophthalmologist for failing vision. +Physically they feel quite well. They have been heavy eaters, hard +workers, men and women who have been under great mental strain. On +examination of the fundus of the eye there is found slight tortuosity of +the vessels with possibly areas of degeneration in the retina. A careful +physical examination will usually reveal the signs of arteriosclerosis +elsewhere. We have mentioned frequently high tension as an early sign. +This must be taken with somewhat of a reservation, for this reason: not +infrequently a persistent high tension is the earliest sign of chronic +nephritis. The arteries may be pipe stem in character and the heart +small and flabby. However, if one watches for the palpably thickened +superficial arteries (always bearing in mind the normal palpability as +age advances) and the high tension, he can not go far wrong in his +treatment whether the case is one of chronic nephritis or of +arteriosclerosis. + +There is also this to bear in mind. Arteriosclerosis may be marked in +some vessels and so slight in the peripheral vessels that it can not +with certainty be made out. But when the radials are sclerosed, it is +usually the case that similar changes exist in other parts. Then too, +there may be marked changes at the root of the aorta leading to +sclerosis of the coronary vessels alone, and the first intimation that +the patient or any one else has that there is disease, may be an attack +of angina pectoris. Except for symptoms on the part of the heart there +is no way to make the diagnosis of sclerosis of the coronary arteries. + + +=Differential Diagnosis= + +In arriving at a diagnosis, when the question is whether or not +arteriosclerosis is the main etiologic factor, the most important fact +to know is the age of the patient. Other points that have been dwelt on +fully must of necessity also be borne in mind. + +Possibly the chief conditions that may be confused with some of the +results of arteriosclerosis are pseudo angina pectoris which may be +mistaken for true angina pectoris, and ulcer of the stomach, +appendicitis (?) or other inflammatory abdominal condition which may be +mistaken for angina abdominalis. + +Differential tables are sometimes of value in fixing the chief points of +difference graphically. + + =Pseudo angina pectoris=. + + Etiology rather certain; hysteria, neurasthenia, toxic agents, and + reflex irritations. + + No age is exempt. Usually in young people, chiefly females. + + Paroxysms of pain occur spontaneously, are periodic and often + nocturnal. + + Pain, while severe, is diffuse and sensation is of distension of + heart. No sense of real anguish. + + Duration may be an hour or more. + + Restlessness and emotional symptoms of causative conditions are + prominent. + + Usually no increase in arterial tension. + + Prognosis favorable. + + + =True angina pectoris=. + + Etiology not certain but almost always associated with + arteriosclerosis of the coronary arteries and also aortic + regurgitation. + + Age is important factor. Rare before forty, and males usually + affected. + + Paroxysms brought on by overexertions or excessive mental emotion. + Rarely periodic. + + Intense pain, radiating down arm; heart felt as in a vise. Sense of + anguish and impending dissolution. + + Duration from few seconds to several minutes. + + Silent and fixed attitude, rigidity rather than restlessness. + + Arterial tension is as a rule increased. + + Prognosis most unfavorable. + +In differentiating between ulcer of the stomach and angina abdominalis +the following points may be of service: + + + =Ulcer=. + + Occurs as a rule in young persons, more often females. + + Pain of boring character increased by food and by certain positions + with food in stomach. Felt through to left of spine. + + Occult blood found in stools. + + Considerable anemia apt to be present. + + Arterial tension usually low. + + + =Angina abdominalis=. + + Only occurs in adults over forty who have been heavy eaters and + drinkers, mostly males. + + Pain cramp-like, diffuse, although more localized in epigastrium. + Not necessarily any connection with food. + + No occult blood in stools. + + Anemia more often absent. + + Arterial tension high. (Splanchnic sclerosis.) + + +=Diseases in Which Arteriosclerosis Is Commonly Found= + +There are certain more or less chronic diseases in which +arteriosclerosis is found either as a separate disease or as a result of +the chronic disease itself, or the sclerosis may be the cause of the +disease. As examples of the first class are diabetes mellitus and +cirrhosis of the liver. As examples of the second class are chronic +nephritis, gout, syphilis, and lead poisoning. Examples of the third +class have already been fully described. Then certain rare diseases that +have been briefly described in this chapter, viz.: Raynaud's disease and +erythromelalgia are frequently associated with demonstrable +arteriosclerosis. + + + + +CHAPTER XI + +PROGNOSIS + + +In a disease that presents as many vagaries as arteriosclerosis, it is +not possible to give a certain prognosis. Unfortunately we do not as a +rule see the arteriosclerotic until the disease is well advanced, or +even after some of the more serious complications have taken place. By +that time the condition is progressive, and while the prognosis is grave +the individual may live a number of years. + +It is fortunate for the arteriosclerotic that mild grades of the disease +are compatible with a fairly active life. The disease in this stage may +become arrested and the patient may live many years. Not only in the +mild grades is this possible. Even patients with advanced sclerosis may +enjoy good health provided the organs have not been so damaged as to +render them unfit to perform their functions. The frequency with which +we see advanced arteriosclerosis at the postmortem table as an +accidental discovery, attests the truth of the foregoing statement. Yet +how often does it happen that individuals, apparently in the best of +health, suddenly succumb to an asthmatic or uremic attack, an apoplexy, +cessation of the heart beat, or a rupture of the heart due to +arteriosclerosis! + +In order to arrive at an intelligent opinion in regard to prognosis +certain factors must be taken into consideration, chief of which are: +the seat of the sclerosis; the probable stage; the existing +complications; and, last and most important, the patient himself. The +whole man must be studied and even then our prognosis must be most +guarded. + +It is much more dangerous for the patient when the process is in the +ascending portion of the arch of the aorta than when it has attacked the +peripheral arteries. Here, at the root of the aorta, are the openings of +the coronary arteries and the arteries supplying the brain are close +by. The coronary arteries here control the situation. When loud murmurs +are heard at the aortic orifice and the heart is evidently diseased, it +is useful to divide the endocarditis into two types, the +arteriosclerotic and the endocarditic. The etiology of the former is +sclerosis and the prognosis is grave because of the liability, nay the +probability, that the orifices of the coronary arteries will become +narrowed. The etiology of the second type is in most cases rheumatic +fever or some other infectious disease, and the prognosis is far better +than in the first type. True, the two may be combined. In such a case, +the prognosis is entirely dependent upon the course of the +arteriosclerosis. + +The involvement of the arteries in the kidneys is of considerable +importance, for it is usually bilateral and widespread. As a rule, the +disease makes but slow progress provided that the general condition of +the patient is good, but at any time from a slight indiscretion or for +no assignable cause, symptoms of renal insufficiency may appear and may +rapidly prove fatal. + +It must not be thought that because the localization of the +arteriosclerosis in the peripheral arteries is usually the most +favorable condition that it is therefore devoid of ill effects. On the +contrary, very serious, even fatal, results may be brought about by +interference with the circulation with resultant extensive gangrene of +the part supplied by the diseased arteries. The amputation of a portion +of a leg, for instance, may relieve, to some extent, an overburdened +heart and prove life-saving to the patient, but the neuritic pains are +not necessarily relieved. The torture from these pains may be +excruciating. + +No stage of the disease is exempt from its particular danger. In the +early stages of the disease before the artery or arteries have had time +to become strengthened by proliferation of the connective tissue, there +is the danger of aneurysm. Later, the very same protective mechanism +leads to stiffening and narrowing of the arteries and hence to +increased work on the part of the heart with all of its consequences. +Thrombosis is favored, and where atheromatous ulcers are formed, +embolism is to be feared. + +As the complications and results of arteriosclerosis come to the front +every one must be considered by itself and as if it were the true +disease. There may be a slight apoplectic attack from which the patient +fully recovers, but the prognosis is now of a grave character, as the +chances are that another attack may supervene and carry off the subject. +Yet, after an apoplectic attack, patients have lived for many years. +Probably the most noted illustration of this is the life of Pasteur. He +had at forty-six hemiplegia with gradual onset. He recovered with a +resulting slight limp, did some of his best work after the stroke, and +lived to be seventy-three years old. Yet the exception but proves the +rule and the prognosis after one apoplectic stroke should always be +guarded. + +The first attack of cardiac asthma is to be looked upon as the beginning +of the end. The end may be postponed for some time, but it comes nearer +with every subsequent attack. One may recover from what appears to be a +fatal attack of cardiac asthma accompanied by edema of the lungs and +irregular, intermittent, laboring heart, but the recovery is slow and +the chances that the next attack will be the fatal one are increased. + +The significance of albuminuria is difficult to determine. The kidneys +secrete albumin under so many conditions that the mere presence of +albumin in the urine may have but little prognostic value. Many cases +are seen where there is no demonstrable albumin, and yet the patient may +suddenly have a cerebral hemorrhage. As a general rule the urine should +be carefully examined, but not too much stress should be laid on the +discovery of albumin and casts. It is not always possible to determine +the extent of the kidney lesion by the urinary examination, yet at any +time a uremic attack may appear and prove fatal. + +After all the most important fact for the patient is not what the +pathologist finds in his kidneys after he is dead, but what the living +functional capacity of the kidneys is. This can now be determined in a +variety of ways as the result of extensive work carried out in quite +recent years. The simplest method of determining the functional capacity +of the kidneys is by the injection into the muscles of the back of a +solution containing 6 mg. of the drug phenolsulphonephthalein in one +c.c. of fluid. This comes already prepared in ampules, with full +directions for its employment.[16] Some clinicians use indigo-carmine in +place of phthalein. The general consensus of opinion is in favor of +phthalein. + + [16] I have found the small colorimeter made by Hynson, Westcott and + Dunning, Baltimore, Mo., costing $5.00, a very practical instrument. + +The nephritic test meal carefully worked out by Mosenthal[17] gives much +valuable information. The determination of the nonprotein nitrogen or +the creatinin in the blood also reveals the functional capacity of the +kidneys.[18] + + [17] Mosenthal, H. O.: Arch. Int. Med., 1915, xvi, 733. + + [18] Myers and Lough: Arch. Int. Med., 1915, xvi, 536. + +One might say that the appearance of albumin in the urine of an +arteriosclerotic where it had not been before, is a bad sign, and in +making a prognosis this must be taken into consideration. + +Bleeding from the nose is not infrequently seen in those who have +arteriosclerosis. It can hardly be called a dangerous symptom as it can +always be controlled by tampons. There are times when epistaxis is +decidedly beneficial as it relieves headache, dizziness, and may avert +the danger of a hemorrhage into the brain substance. It is rare to have +nose bleed except in cases of high tension in plethoric individuals. My +experience has been that it has saved me the trouble of bleeding the +patient. It is always of serious import in that it indicates a high +degree of tension, but there is scarcely ever any immediate danger from +the nose bleed itself. + +Intestinal hemorrhage is always a grave sign. As has been shown, +arteriosclerosis of the splanchnic vessels not infrequently occurs, and +an embolus or thrombus may completely occlude the superior mesenteric +artery. The chances of the establishment of a collateral circulation are +small, as the arteries of the intestines are end arteries. Necrosis of +the part follows, blood is found in the stools, and perforation or +gangrene, or both, are apt to follow. There may be blocking of small +branches only, leading to ulceration of the intestine. Under all +conditions the prognosis is serious. + +The general condition of the patient, his build, physical strength, +powers of recuperation, etc., must be taken into account in giving a +prognosis. The more powerful the individual, the more favorable, as a +rule, is the prognosis, with this reservation always in mind, that the +greater the body development, the greater is the heart hypertrophy, and +the accidents from high tension must not be overlooked. Many puny +individuals with stiff, calcified arteries go about with more ease than +a robust man with thickened arteries only. The differentiation as +pointed out by Allbutt (page 186), is well to keep in mind in giving a +prognosis. It can not be too strongly emphasized that it is the whole +patient that we must consider and not any one system that at the time +happens to be the seat of greatest trouble, and by its group of symptoms +dominates the picture. + +It is evident from what has been said that an accurate prognosis in +arteriosclerosis is no easy matter. Were arteriosclerosis a simple +disease of an acute character there might be grounds for giving a more +or less definite prognosis. The most that can be said is that +arteriosclerosis is always a serious disease from the time that symptoms +begin to make themselves known. The gravity depends altogether on the +seat of the greatest arterial changes, and is necessarily greater when +the seat is in the brain than when it is in the legs or arms. + +The attitude of the patient himself also determines to a great extent +the prognosis. Some men, especially those who have always enjoyed good +health, turn a deaf ear to warnings and instead of ordering their lives +according to the advice of the physician, persist in going their own way +in the hope that the luck that has always been with them will continue +to stand at their elbows. Neither firmness nor pleadings avail with some +men. The only salve for the conscience of the physician is that he has +done his best to steer the patient away from the shoals and breakers. In +others who realize their condition and take advantage of the advice +given as to the regulation of their lives, the prognosis is generally +favorable. + +To sum up the chapter in a few words, I should say: Always remember that +the patient is a human being; study his habits and character and mode of +life; look at him as a whole; take everything into consideration, and +give always a guarded prognosis. + + + + +CHAPTER XII + +PROPHYLAXIS + + +Arteriosclerosis comes to almost every one who lives out his allotted +time of life. As has been noted within, many diseases and many habits of +life are conducive to the early appearance of arterial degeneration. +Decay and degeneration of the tissues are necessary concomitants of +advancing years and none of us can escape growing old. From the period +of adolescence certain of the tissues are commencing a retrograde +metamorphosis, and hand in hand with this goes the deposit of fibrous +tissue which later may become calcified. The arterial tissue is no +exception to this rule, and we have already shown that certain changes +normally take place as the individual grows older, changes which are +arteriosclerotic in type and are quite like those caused in younger +people by many of the etiologic factors of the disease. + +We are absolutely dependent upon the integrity of our hearts and blood +vessels for the maintenance of activity and span of life. Respiration +may cease and be carried on artificially for many hours while the heart +continues to beat. Even the heart has been massaged and the individual +has been brought back to life after its pulsations have ceased, but such +cases are few in number. We can not live without the heart beat and the +prophylaxis of arteriosclerosis consists in the adjustment of our lives +to our environment, so that we may get the maximum amount of work +accomplished with the minimum amount of wear and tear on the blood +vessels. + +The struggle for existence is keen. Competition in every profession or +trade is exceedingly acute, so much so that to rise to the head in any +branch of human activity requires exceptional powers of mind. Among +those who are entered in this keen competition, the fittest only can +survive for any period of time. The weaklings are bound to succumb. A +scion of healthy stock will stand the wear and tear far better than will +the progeny of diseased parentage. + +It is only necessary to call attention to the part that alcohol, +syphilis and insanity play in heredity. These have been discussed fully +in the earlier part of this book. + +We live rapidly, burning the candle at both ends. It is not strange that +so many comparatively young men and women grow old prematurely. While +heredity is a factor as far as the prophylaxis of arteriosclerosis is +concerned, of far more importance is the mode of life of the individual. +Scarcely any of us lead strictly temperate lives. If we do not abuse our +bodies by excessive eating and drinking and so wear out our splanchnic +vessels and cause general sclerosis by the high tension thereby induced, +we abuse our bodies by excessive brain work and worry with all their +multitudinous evils. The prophylaxis of arteriosclerosis might well be +labeled, "The plea for a more rational mode of life." Moderation in all +things is the keynote to health, and to grow old gracefully is an art +that admits of cultivation. Excesses of any kind, be they mental, moral, +or physical, tend to wear out the organism. + +People habitually eat too much; many drink too much. They throw into the +vascular system excessive fluid combined frequently with toxic products +that cause eventually a condition of high arterial tension. It has been +shown how poisonous substances absorbed from the intestines have some +influence on the blood pressure. Anything that causes constant increase +of pressure should be studiously avoided. + +Mild exercise is an essential feature of prophylaxis. One may, by +judicious exercise and diet, make of himself a powerful muscular man +without, at the same time, raising his average blood pressure. The man +who goes to excess and continually overburdens his heart, will suffer +the consequences, for the bill with compound interest will be charged +against him. It is a great mistake for any one to work incessantly with +no physical relaxation of any kind, and yet, after all, it is not so +much physical relaxation that is necessary, as the pursuit of something +entirely different, so that the mind may be carried into channels other +than the accustomed routes. Diversification of interests is as a rule +restful. That is what every man who reaches adult life should aim at. +Hobbies are sometimes the salvation of men. They may be ridden hard, but +even then they are helpful in bearing one completely away from daily +cares and worries. The man who can keep the balance between his mental +and physical work is the man who will, other things being equal, live +the longest and enjoy the best health. + +Nowadays the trend of medicine is toward prophylaxis. We give the state +authority to control epidemics so far as it is possible by modern +measures to control them. + +We urge over and over again the value of early diagnosis in all chronic +diseases, for we know that many of them, and this applies particularly +to arteriosclerosis, could be prevented from advancing by the +recognition of the condition and the institution of proper hygienic and +medicinal treatment. + +_It is the patent duty of every physician to instruct the members of his +clientele in the fundamental rules of health._ Recently the President of +the American Medical Association, in his address before the 1908 +meeting, urged the dissemination of accurate knowledge concerning +diseases among the laity. While this may be done by city and state +boards of health, it seems far better for the modern trained physician +to work among his own people. With concise information concerning the +modes of infection and the dangers of waiting until a disease has a firm +hold before consulting the health mender, people should be able to +protect themselves from infections and be able to nip chronic processes +in the bud. But it is difficult to turn the average individual away from +the habit of having a drug-clerk prescribe a dose of medicine for the +ailment that troubles him. It is really unfortunate that most of the +pains and aches and morbid sensations that one has speedily pass away +with little or no treatment. Herein lies the strength of charlatanism +and quackery. Unfortunate, yes, for a man can not tell whether the +trivial complaint from which he suffers is any different from the one +that was so easily conquered six months ago. But instead of recovering, +he grows worse. Hope that springs eternal in the human breast, leads him +to dilly-dally until he at last seeks medical advice, only to find that +the disease has made such progress that little can be done. + +_Instruct the public to consult the doctors twice a year._ The dentists +have their patients return to them at stated intervals only to see if +all is well. _How much more rational it would be if men and women past +the age of forty had a physical examination made twice a year to find +out if all is well._ + +The prophylaxis of arteriosclerosis is moderation in all the duties and +pleasures of life. This in no sense means that a man has to nurse +himself into neurasthenia for fear that something will happen to him. As +one grows in years exercise should not be as violent as it was when +younger, and food should be taken in smaller quantities. Many forms of +exercise suggest themselves, particularly walking and golf. Walking is a +much neglected form of exercise which, in these modern days with our +thousand and one means of locomotion, is becoming almost extinct. There +is no better form of exercise than graded walking. To strengthen the +heart selected hill climbing is one of the best therapeutic methods that +we have. The patient is made to exercise his heart just as he is made to +exercise his legs, and as with exercise of voluntary muscles comes +increase in strength, so by fitting exercise may the heart muscle be +increased in power. A warning should be sounded, however, against over +exercise. This leads naturally to hypertrophy with all its disastrous +possibilities. Men who have been athletes when young should guard +against overeating and lack of exercise as they grow older. Many of the +factors which favor the development of arteriosclerosis are already +there, and a sedentary, ordinary life, such as office all day, club in +afternoon, a few drinks and much rich food, will inevitably lead to +well-advanced arterial disease. + +Karl Marx in his famous Socialistic platform said: "No rights without +duties; no duties without rights." So we may paraphrase this and say: +"No brain work without moderate physical exercise in the open air; no +physical exercise without moderate brain work." + +There is yet one other point that is important, the combination of +concentrated brain work and constant whiskey drinking. This is most +often seen in men of forty-five to fifty-five, heads of large business +concerns who habitually take from six to twelve drinks of whiskey daily, +and with possibly a bottle of wine for dinner. Such men appear ruddy and +in prime health but, almost invariably, careful examination will reveal +unmistakable signs of arterial disease. There is usually the enlarged +heart and pulse of high tension with or without the trace of albumin in +the urine. The lurking danger of this group of manifestations has so +impressed the medical directors of several of the large insurance +companies that a blood pressure reading must be made on all applicants +over forty years of age. Should high blood pressure be found, the +premium is increased, as the expectation of life is proportionately +shorter in such men than in normal persons. + +Therefore, let every physician act his part as guardian of health. Only +in this way is the prophylaxis of arteriosclerosis possible. + + + + +CHAPTER XIII + +TREATMENT + + +Although it has been rather dogmatically stated (vide supra) that every +one who reaches old age has arteriosclerosis, it must not be inferred +that absolutely no exceptions to this rule are found. Cases are known +where persons of ninety years even had soft arteries, and we have seen +persons of eighty whose arteries could not be palpated. When infants and +children are seen with considerable sclerosis, it proves that, after +all, it is the quality of the tissue even more than the wear and tear, +that is the determining factor in the production of arteriosclerosis. It +would be well if those who can not bring healthy progeny into the world +were to leave this duty to those who can. + +In general the treatment of arteriosclerosis is prophylactic and +symptomatic. In the preceding chapter I had something to say about +prophylaxis in general; I must again refer to it in detail. + +Arteriosclerosis is essentially a chronic progressive disease, and the +secret of success in the management of it is not to treat the disease or +the stage of the disease, but to treat the patient who has the disease. +To infer the stage of the disease from the feeling of the sclerosed +artery, may lead to serious mistakes. Persons with calcified arteries +may be perfectly comfortable, while those with only moderate thickening +may have many severe symptoms. The keynote is individualization. It is +manifestly absurd to treat the laboring man with his arteriosclerosis as +one would treat the successful financier. The habits, mode of life, +every detail, should be studied in every patient if we expect to gain +the greatest measure of success in the treatment. One may treat fifty +patients who have typhoid fever by a routine method and all may +recover. Individualizing, while of great value in the treatment of acute +diseases, yet is not absolutely essential in order that good results may +be obtained. Far different is it when treating a disease like +arteriosclerosis. One who relies on textbook knowledge will find himself +at a loss to know what to do. Textbooks can only outline, in the +briefest manner, the average case, and no one ever sees the average book +case. At the bedside with the patients is the place to learn +therapeutics as well as diagnosis. All that can be hoped for in +outlining the treatment of arteriosclerosis is to lay down a few +principles. The tact, the intuition, the subtle something that makes the +successful therapeutist, can not be learned from books. So the man who +treats cases by rule of thumb is a failure from the beginning. There are +certain general principles that will be our sheet anchors at all times +and for all cases. The art of varying the application of these +fundamentals to suit the individual case, is not to be culled from +printed words. + + +=Hygienic Treatment= + +Every man is more or less the arbiter of his own fate. Granted that he +has good tissue to begin life, his own habits and actions determine his +span of comfortable existence. No one cares to live after his brain +begins to fail, and the failing brain is often due to disease of the +cranial arteries. The hygienic treatment resolves itself into advice in +regard to prophylaxis. + +First and foremost is exercise. It has seemed to us that the revival of +out-of-door sports is one of the best signs of promise of the +preservation of a virile, hardy race. That women, as well as men, +indulge in the lighter forms of out-of-door exercise should bring it +about that the coming generation will start in life under the most +advantageous conditions of bodily resistance. + +Among all the forms of exercise, golf probably is the best. It is not +too violent for the middle-aged man, yet it gives the young athlete +quite enough exercise to tire him. It is played in the open. One is +compelled to walk up and down in pleasant company, for golf is +essentially a companionable game, while he reaps the full benefit of the +invigorating exercise. The blood courses through the muscles and lungs +more rapidly; the contraction of the skeletal muscles serves to compress +the veins and so to aid the return of blood to the heart: the lungs are +rendered hyperemic, deeper and fuller breaths must be taken; oxidation +is necessarily more rapid, and effete products, which if not completely +oxidized would possibly act as vasoconstrictors, are oxidized to +harmless products and eliminated without irritating the excretory +organs. + +Other forms of out-door exercise that can be recommended are tennis, +canoeing, rowing, fishing, horseback riding, swimming, etc. Tennis is +the most violent of all the sports mentioned and might readily be +overdone. Rowing as practiced by the eights at college is undoubtedly +too violent a form of exercise, and may be productive in later life of +very grave results. Canoeing is a delightful and invigorating exercise. +The muscles of the arms, shoulders, and trunk are especially used, the +leg muscles scarcely at all. Nevertheless, the deep breathing that +necessarily comes with all chest exercises aerates every portion of the +lungs, and is of great benefit to the whole body. + +Swimming as an exercise has much to recommend it. In this sport all the +muscles take part and at the same time the chest is broadened and +deepened. + +All these methods of using the muscles to keep oneself in trim, so to +speak, are part and parcel of the general hygienic mode of life that is +conducive to a healthy old age. Exercise can be overdone, as eating can +be overdone. Both are essential and yet both can be the means of +hastening an individual to a premature grave. + +When the arteriosclerosis has advanced so far that it is easily +recognizable, certain forms of exercise should be absolutely prohibited. +Such are tennis, rowing and swimming. Horseback riding to be allowed +must be strictly supervised. At times this may be an exceedingly violent +exercise. As an out-of-door sport, there is nothing that equals golf. +The physician, knowing the character of the course, and the length of +it, can say to his patient that he may play six, nine, twelve, or +eighteen holes, depending on the patient's condition. + +For those who are not able to get out, exercise in the room with the +windows open must take the place of out-of-door sports. Here the use of +chest weights is a most excellent means of keeping up the tone of the +muscles. By adjusting the weights, the exercise may be made light, +medium, or heavy. Every physician should be familiar with the chest +weight exercises. They are not as good as open air exercise but they +undoubtedly have been the means of saving years of life to many patients +with arterial disease. + +There comes a time when all forms of exercise must be prohibited on +account of the dyspnea, edema, dizziness, etc. It seems unwise to keep +such a patient in bed, even though the edema be considerable. Once on +his back in bed he becomes weak, and the danger of edema of the lungs or +hypostatic congestion of the bases, with subsequent bronchopneumonia, is +very great. + +Such patients may be allowed to sit up in a comfortable chair with the +legs supported straight out on a stool or other chair. The half +reclining position is not easy to assume in bed. Considerable ingenuity +must often be exercised by the physician in making the patient +comfortable without increasing the symptoms from which the patient +suffers following the least amount of exercise. Although such persons +can not exercise actively, they should have passive exercise in the form +of massage, carefully given, so that no injury is done to the rigid +vessels. It is possible to rupture a vessel, the walls of which are +encrusted with lime salts, and full of small aneurysmal dilatations. +Every patient must be watched carefully and measures instituted for the +individual. + + +=Balneotherapy= + +As a tonic and invigorator, the cold or cool bath (shower or tub), in +the morning on arising can be highly recommended. It promotes skin +activity, is a stimulant to the bowels and kidneys and to the general +circulation, besides being cleansing. We find today that the morning +bath has become such a necessity to the average American that all new +hotels are fitted with private baths, and old hotels, in order to get +patronage, are arranging as many baths connected with sleeping rooms as +is possible. Our generation assuredly is a ruddy, clean-bodied one. What +the actual results of this out-door life and frequent bathing will be +for the race remains to be seen, but one can not but feel that it must +build up a stronger, more resistant race of people, who not only enjoy +better health than did their forefathers, but enjoy it longer. + +Not every one can stand a cold bath. It is folly to urge it on one to +whom it is distasteful, or on one who does not feel the comfortable glow +that should naturally result. For the well, or those with a tendency to +arteriosclerosis, or those in whose families there have been several +members who had early arteriosclerosis, such proceedings as recommended +could not be improved upon. However, for the person who has well +recognized sclerosis, only warm baths should be advised, and these not +daily. The water should be at a temperature of 90-95 deg. F. Care should be +taken that persons sent to spas be cautioned against hot baths. It is +not inconceivable that the increased force of the heart beat that +accompanies a hot bath might be sufficient to rupture a small cranial +vessel. Hence, Turkish and Russian baths should be most unqualifiedly +condemned. As a matter of fact, persons vary so in their habits with +regard to bathing that what might suit one person would do another much +harm. + + +=Personal Habits= + +The personal habits of the individual, more than any other factor, +determine whether or not arteriosclerosis sets in early in his life. The +man or woman who is moderate in eating and drinking, sees that the +kidneys are kept in good condition, and attends strictly to regularity +of the bowels, lays a good basis for the measure of health which is so +essential for happiness. It has been shown that sclerosis of the +splanchnic vessels may be due to constant irritation of toxic products +elaborated in digesting constantly enormous meals. In obstinate +constipation, many poisons, the nature of which we do not know, are +absorbed and circulate in the blood. We have not sufficient data to +prove that constipation favors the production of arteriosclerosis, but +our impression has been that it does favor it. Constipation can often be +relieved by a glass of water before breakfast, a regular time to go to +stool, and abdominal massage or exercises. Some maintain that it is a +bad habit only, and can be readily overcome. Whatever is done, avoid +leading the patient into the drug habit, for the last state of the +patient will be worse than the first. Habits of sleep are not of such +great importance. Most persons get enough sleep except when under severe +mental strain. Most adults need from seven to eight hours' sleep, +although some can do all their work and keep in prime health on five or +six hours' sleep. + +Tobacco has been accused of causing many ills and has been thereby much +maligned. We can not see that the use of tobacco in any form in +moderation is harmful to most men. Undoubtedly the blood pressure is +raised when mild tobacco poisoning occurs, and individual peculiarities +of reaction to the weed are multitudinous. But to condemn offhand its +use is the height of folly. There is no reason why the arteriosclerotic +who has always used tobacco in moderation, should not continue to use +it, whether he smoke cigarettes, cigars, or pipe. His supply should be +decreased, but there is no sense in depriving a man of one of the +solaces of life, unless, as is sometimes the case, abstinence is easier +for the patient than moderation. + +As for alcohol, opinions differ widely.[19] Some see in alcohol one of +the most frequent causes of arteriosclerosis; others do not believe that +the part played by alcohol is a serious one, only in conjunction with +other poisonous substances is it dangerous. Probably unreasoning +fanaticism has had much to do with the wholesale condemnation of +alcoholic beverages. The general effect of alcohol is to lower the blood +pressure by causing marked dilatation of all the vessels of the skin. +True, the alcohol circulates in the blood, and is broken up in the +liver, and this organ would seem to bear the brunt of the harm done. +Alcoholic drinks in moderation, I do not believe have any deleterious +effect on health. On the contrary, I believe that they may in some cases +assist digestion and assimilation. Indiscriminate indulgence is to be +condemned, as is overindulgence in exercise or eating. What may be +moderate for A, might be excessive for B. Every man is then the arbiter +of his own fortune and within his own limits can indulge moderately (a +relative term after all) without fear of doing himself harm. In advanced +arteriosclerosis it is necessary to decrease the supply of alcohol just +as it is necessary to cut down the food supply. This must rest entirely +on the judgment of the physician, who must not act arbitrarily, but must +have his reasons for every one of his orders. + + [19] Discussion of alcohol at present has value only as it relates + to the past. The present is dry. The future is in the lap of the gods. + + +=Dietetic Treatment= + +Most persons eat too much. We not only satisfy our hunger, but we +satisfy our palates, and, instead of putting substantial foodstuffs +into our stomachs, we frequently take unto ourselves concoctions that +defy description. + +Foodstuffs are composed of one or all of three classes: (1) proteins, +(2) fats, (3) carbohydrates. As examples of the first are beef and white +of egg; of the second, the oils, butter, lard; of the third, sugar, +potato, beet, corn, etc. + +The physiologists and chemists have shown us that both endogenous and +exogenous uric acid in excess will cause a rise of blood pressure, but +the bodies most concerned in the production of elevated blood pressure +are the purin bodies, those organic compounds which are formed from +proteins and represent chemically a step in the oxidation of part of the +protein molecule to uric acid. Red meat contains more of the substances +producing purin bodies than any other one common foodstuff, and for this +reason the excessive meat eater is, _ceteris paribus_, more apt to +develop arteriosclerosis comparatively early in life. + +The fats and carbohydrates contain practically no substances that react +on the body of the ordinary individual in a deleterious manner during +their digestion. The extra work that is put on the heart by the +formation of many new blood vessels in adipose tissue is the only +harmful effect of overindulgence in these foodstuffs. + +It has been found that nitrogen equilibrium can be maintained at a wide +range of levels. Formerly 135-150 gms. of protein daily were considered +necessary for a man doing light work. Now it is known that half that +amount is sufficient to keep one in nitrogenous equilibrium, and to +enable one to keep his weight. A person at rest requires even less than +that. One who is engaged in hard physical labor burns up more fuel in +the muscles, and so must have a larger fuel supply. + +Although we habitually eat too much we drink too little water. For those +who have any form of arterial disease an excess of fluid is harmful, as +the vessels become filled up and a condition of plethora results, which +necessarily reacts injuriously on the heart and circulation. The +drinking of a glass of water during meals is, in the author's opinion, +good practice. The water must be taken mouthful at a time, and not +gulped down. If this is done, there results sufficient dilution of the +solid food to enable the gastric juices successfully and rapidly to +reach all parts of the meal. + +Some are in favor of a rigid milk diet for those who have +arteriosclerosis. Some men have lived on nothing but milk for several +years and have not only kept in good health, but have actually gained +weight and led at the same time active lives. It has been held by others +that rigid milk diet is positively harmful on account of the relatively +large quantity of calcium salts that are ingested. This was thought to +favor the deposition of calcareous material in the walls of the already +diseased arteries. While possibly there may be some danger of increased +calcification, the majority of clinicians are in favor of a milk cure +given at intervals. Thus the patient is made to take three to four +quarts daily for a period of a month. There is then a gradual return to +a general diet, exclusive of meat, for several weeks, then another rigid +milk diet period. + +If we are bold enough to follow Metschnikoff in his theories of +longevity, we might advise resection of the large intestine, on the +ground that it is an enormous culture tube that produces prodigious +amounts of poisonous substances which are thrown into the general +circulation. To combat such a grave (?) condition as the carrying of +several feet of large intestine, we are recommended to take buttermilk +or milk soured by means of the _b. acidus lacticus_. Clinical experience +has taught that in arteriosclerosis buttermilk is of great value, +whether it be the natural product, or made directly from sweet milk by +the addition of the bacilli. The latter is a smoother product and has, +to my mind, a delightful flavor. It may be diluted with Vichy or plain +soda water. Cases that can not take milk or any other food will often +take buttermilk, and do well on this restricted diet. From two to four +quarts daily should be taken. It should be drunk slowly as should milk. + + +=Medicinal= + +It has long been thought that the iodides have some specific effect on +the advancing arteriosclerosis, checking its spread, if not really +aiding nature to a limited restoration of the diseased arteries. It is +possible that the eulogies upon the iodides owe their origin to the +successful treatment of syphilitic arteriosclerosis, in which condition +these drugs have a specific action. However that may be, there is no +doubt that the administration of sodium or potassium iodide is good +therapeutics in cases of arteriosclerosis. + +Unfortunately many persons have such irritable stomachs that they can +not take the iodides, even though they be diluted many times. They may +be made less irritating by giving them with essence of pepsin. Unless +the case is syphilitic, it is doubtful whether it is of value to +increase the dose gradually until a dram or even more is taken three +times daily after meals. Usually a maximum dose of ten grains seems to +be quite sufficient. This may be taken three times a day, well diluted, +for three months. There follows a month's rest, then the treatment is +resumed for another period of three months, and so on. Either sodium or +potassium iodide in saturated solution may be given. The sodium salt is +possibly less irritating, and contains more free iodine than the +potassium salt, although the latter is more generally used. The +strontium iodide may also be used. + +One sees a patient now and then who can not take the iodides, however +they may be combined. For such patients one may obtain good results with +iodopin, sajodin, or other of the preparations put up by reputable +firms. Personally I have never yet seen a patient who could not take the +ordinary iodides in some form or other, and I am opposed to ready made +drugging. + +The action of the iodides is to lower the blood pressure, and they are +of greatest value when the blood pressure is high, and when headache and +precordial pain are present. + +When the case is moderately advanced, very mild doses, gr. 1/2, morning +and evening, of the thyroid extract may be given. It is generally +believed that the internal secretion of the thyroid and the adrenal are +antagonistic. That the thyroid secretion lowers blood pressure in +certain forms of hypertension is certain, possibly on account of its +iodine content. Some combinations of iodine and thyroid such as the +iodothyroidin have been used and have had some measure of success +attributed to them. + +Hypertension does not always demand active measures for its reduction. +Viewed from the physiologic standpoint, hypertension is but the +expression of a compensating mechanism which is designed to keep the +blood moving through narrowed channels. Heart hypertrophy then is +absolutely essential to the maintenance of life. It has been said that +the highest blood pressures occur in chronic disease of the kidneys. The +poisonous substances produced in the kidneys must exert their action +through absorption into the general blood stream. This toxin may be +completely eliminated, if we accept as our criterion the reduction of +tension to normal together with the complete return of the affected +individual to health. A concrete example is as follows: A man aged 44 +years was brought to the Milwaukee County Hospital in coma. His systolic +blood pressure was over 280 mm. Hg, diastolic 170 mm., his urine +contained considerable albumin and many casts. He had general anasarca. +Venesection was done at once and 300 c.c. blood obtained. Immediately +following this operation the pressure was 210-150, but within twelve +hours it was again above 280-170. He was given no medication to reduce +pressure except that he was freely purged. He was given a steam sweat +bath daily. Frequent blood pressure readings were taken. Within seven +days the pressure was 130-86. He had, in the meantime, completely +recovered from his symptoms. He was kept in the hospital for two weeks +longer assisting in the work on the ward, and he was discharged with a +pressure (systolic) between 130 and 136 diastolic 80-84. The treatment +was rest in bed, free purging, venesection, and sweat baths, simple but +exceedingly effective. + +Should there be actual indications for reducing the blood pressure, I +must admit that it can not always be done. The majority of cases will do +well on the sodium nitrite or erythrol tetranitrate. However, these do +not always lower blood pressure and keep it within normal limits. When a +man has very high tension we do not wish to reduce it to what it should +normally be for the age of the patient, as symptoms of collapse might +set in at any time under such conditions. + +Observations made with the sphygmomanometer[20] show that the effect of +nitroglycerin is transient or of no effect except in doses which are +relatively enormous (one drop of the one per cent solution given every +hour). Sodium nitrite may lower the blood pressure but the effects will +have worn off in two hours. It is the same with erythrol tetranitrate. +Sodium sulphocyanate in doses of from one to three grains three times a +day is highly recommended by some. My own experience with it does not +lead me to believe that it is of any great value in hypertension. It, +however, may be tried. Benzyl benzoate has been used recently to reduce +the high blood pressure of hypertension. Macht has reported some +success. In the author's hands it has been efficacious in a few cases. +As long as the patient takes the drug the pressure may be slightly +reduced, but upon the withdrawal of the drug the pressure returns to its +former level. It is well worth a trial and further experimentation may +reveal better methods of administration. The dose is from 2 to 6 c.c. +mixed with water at intervals. + + [20] Miller, Jos. L.: Hypertension and the Value of the Various + Methods for Its Reduction. Jour. Am. Med. Assn., 1910, liv, p. 1666. + +In the hypertension of the menopause some have had success with large +doses of corpus luteum extract. As a matter of fact the drug treatment +of hypertension, when it becomes necessary to treat this condition with +drugs, has suffered a notable set-back since more careful control has +been made with the blood pressure instruments. In giving any of the +depressor drugs their action should be controlled by blood pressure +measurements, for only in this way can we be sure that the drug is +exerting its physiological effect and we may expect results. The +individual reaction to these drugs varies greatly and no rule for dosage +can be dogmatically laid down. The only successful therapy is rigid +individualization. This is the keystone to treatment in cases of +arteriosclerosis and high tension. + +It must not be inferred from what has been said that the nitrites are of +no value. They are of decided value but they have their limitations. The +most evanescent of these drugs is amyl nitrite. This is put up in the +form of capsules, or pearls, containing from one to three minims. When +it is desired to dilate the peripheral vessels suddenly, one or two of +these capsules are broken in a cloth held to the nose. The effect is +almost instantaneous. There is flushing of the face and other peripheral +vessels, particularly near the head, denoting a relaxation and widening +of the bed of the blood stream, and a consequent decrease in pressure in +the arteries. These effects are over in a short while. It is only used +in attacks of cardiac spasm, as in angina pectoris. Nitroglycerin, the +Spiritus Glonoini of the U. S. P., acts in about the same manner as amyl +nitrite but the effects last usually a trifle longer. One drop of the +one per cent solution may be given every hour until physiologic effects +are produced. It may be given hypodermically. This may be a means of +reducing pronounced high tension. This drug has been found of benefit +especially in cases where arteriosclerosis combined with chronic +nephritis causes cardiac asthma. The other drug which may be of service +in these conditions, one whose sphere of action is somewhat broader, +because its effects are more lasting, is sodium nitrite. This is given +in water in doses of one to three or five grains every four hours. Some +have objected to the use of this drug, but my experience has made me +place considerable confidence in its harmlessness, provided that the +patient is carefully watched. This, however, applies to all of the +nitrite compounds. My experience with erythrol tetranitrate is not +large. It may be used in place of sodium nitrite. + +For a mild case, one often finds that sweet spirits of niter is +sufficient to control the pressure and relieve the distressing symptoms, +and it is undoubtedly the least harmful of all the nitrites. Drugs that +are of great value, but of which little is noted in textbooks, are +aconite and veratrum viride. Both of these drugs are well known to be +marked circulatory depressors. Veratrum viride in my experience should +be very cautiously used, and never used unless a trained attendant is +constantly at hand. With regard to aconite I have no such feeling, and a +mixture of tincture of aconite and spiritus etheris nitrosi may be given +for several weeks with no fear of doing any harm. Personally, of all the +drugs mentioned, I prefer the nitrite of sodium or the combination just +given. They may be advantageously alternated. + +My own feeling is that the most successful means of treatment of acute +high tension is without the use of drugs. The most important measure is +absolute rest in bed. This often suffices to lower the blood pressure +and to arrest the symptoms produced by high tension. Venesection I +believe is also of value. True the arterioles appear to contract almost +immediately upon the lessened quantity of blood, or there is immediate +interchange of serum from the tissues which brings the blood volume +back to the original amount. Whatever happens the pressure is not +greatly reduced, at times not reduced at all, but often the symptoms are +relieved. Hot packs or sweat baths assuredly do reduce the pressure in +many cases. This seems to me to be an exceedingly valuable measure. +Finally the diet should be nourishing, but very light, not too much +fluid should be ingested, and the bowels should be freely opened. + +With the fibrolysin of Merck, I have had no experience. Some men assert +that they have had good results from its use, but on the whole the +evidence is not highly favorable. + +Morphine is invaluable. No drug is of such value in the nocturnal +dyspneic attacks that occur in the late stages of arteriosclerosis when +the heart or the kidneys are failing. Morphine not only relaxes spasm +and quiets the cerebral centers, but is an actual heart stimulant under +such conditions, and should never be withheld, as the danger of the +patient's becoming addicted to its use is more fanciful than real. +However, morphine, at times, suppresses the secretion of urine. So that +if after trial the urine becomes scanty and the edema increases, +recourse must be had to other drugs. The various hypnotics may be used +with caution. One which seems to be very useful is adalin. + +As heart stimulants, one may use strychnine, spartein, caffein, or +camphor. In desperate cases, where a rapidly diffusible stimulant is +needed, a hypodermic syringeful of ether may be given, and repeated in a +short while. + +Several years ago a so-called serum was brought out by Trunecek which +was said to have a favorable effect on the metabolism of the vessel +walls. It was given at first hypodermatically or intravenously but the +former method was painful. It was later stated that given by mouth it +acted just as well. The results with the Trunecek serum have not come up +to the expectations that the early favorable reports promised. The +original serum was composed as follows: NaCl, 4.92 gm.; Na_2SO_4, 0.44 +gm.; Na_2CO_3, 0.21 gm.; K_2SO_4, 0.40 gm.; aqua destil. q. s. ad. 100.0 +c.c. Later this was modified for internal use to the following +prescription: + + R_{x} Natrii chlor. 10. gm. + Natrii sulphat. 1. gm. + Natrii carbonat. 0.40 gm. + Natrii phosphat. 0.30 gm. + Calcii phosphat. + Magnesii phosphat. aa. 0.75 gm. + M. Ft. cachets No. XIII. + +The contents of every cachet corresponds to 15 c.c. of the fluid serum +or to 150 c.c. of blood serum. The preparation called antisclerosin +consists of the salts contained in the serum. As to its efficacy, I can +not judge, as I have never felt that it was worth while to use it. +Reports of cases in which it has been tried do not speak very highly of +it. + +In the general treatment of arteriosclerosis, there is no one factor of +more importance than the regular daily bowel movement. Attention to this +may save the patient much discomfort and even acute attacks of cardiac +embarrassment. The choice of the purgative is immaterial, with this +reservation only, that the mild ones, such as cascara, rhubarb, licorice +powder and the mineral waters, should be thoroughly tried before we +resort to the more drastic purgatives. Plenolphthalein in 3 to 5 grain +doses acts remarkably well in some people as a pleasant laxative. +Agar-agar with or without cascara may be useful. + +Liquid paraffin under a variety of names is a most useful and +efficacious laxative. As its action is purely mechanical it may be taken +indefinitely without doing harm to the intestinal musculature. + +The old Lady Webster dinner pill is an excellent tonic aperient. When +the heart is embarrassed and edema of the legs and effusion into the +serous cavities have taken place, then it becomes necessary to use the +drastic purgatives that cause a number of watery movements. Epsom salts +given in concentrated form, elaterin gr. 1-12, the compound cathartic +pill, blue mass and scammony, or even croton oil may be used. Since the +observation of a greatly congested intestine from a patient who had been +given croton oil, I have ceased to use this purgative, and I doubt much +whether its use is ever justifiable in these cases. + +The management of the ordinary case of arteriosclerosis resolves itself +into a careful hygienic and dietetic regime with the addition of the +iodides, aconite, or the nitrites. A diet consisting of very little +meat, alcohol in moderation or even absolutely prohibited, and not too +much fluid should be prescribed. Condiments and spices should also be +used sparingly. Cold baths, shower baths, cold and hot sheets +alternating, are of great benefit in assisting the heart to do its best +work by making the large capillary area of the skin more permeable. It +is not true that such baths raise the blood pressure so markedly. +Certain acts, as sneezing, violent coughing, etc., increase the blood +pressure much more than judicious bathing. + + +=Symptomatic Treatment= + +The fact that arteriosclerosis really loses much of its own identity +and, in later stages, becomes merged with the symptomatology of the +diseases of various organs, as the kidney, brain, heart, compels us, for +completeness' sake, to say a few words about the treatment of these +complications. + +One of the results of arteriosclerosis of the coronary arteries, angina +pectoris, demands prompt treatment. In the acute attack, the chief +object is to relieve the spasm and pain. Pearls of amyl nitrite should +be inhaled, and morphine sulphate with atropine sulphate given +hypodermatically at the very earliest moment. It is senseless to +withhold morphine. The only possible reason for withholding it would be +uncertainty as to the diagnosis. It is probably better to err on the +safe side, and should the case prove to be one of pseudo angina, in the +next attack sterile water can be given instead of the morphine and +atropine. + +When a patient is seen in the condition of broken compensation with the +much dilated heart, anasarca, dyspnea and suppression of urine, there is +no better practice than venesection. Especially is this valuable when +the tension is still fairly high and the individual is robust. Following +the abstraction of six to eight ounces of blood (300-500 c.c.)[21] the +whole picture changes, so that a man who a short while before was +apparently at death's door, notices his surroundings and takes an +interest again in life. This should be followed up with thorough +purgation, and cardiac stimulants should be ordered. In such cases +digitalis is useful, but its action is never so striking as in cases of +this general character due to uncompensated valvular disease. It must be +remembered that in arteriosclerosis the changes in the myocardium must +be of a considerable grade for the heart to give away. Therefore, +digitalis can not be expected to act on a diseased muscle as it acts on +a comparatively healthy muscle. It is only in such cases of broken +compensation that digitalis should ever be used. + + [21] I have taken as much as 1700 c.c. from a large man. He + recovered and went back to work. + +Digitalis is not a general vasoconstrictor as used to be taught. Its +action on the kidney is actually a vasodilator one. And in its action on +the heart the digitonin dilates the coronary arteries, according to +Macht, while the digitoxin acts on the heart muscle. Overdosing with +digitalis has produced partial heart block in many cases. It is +absolutely contraindicated in Stokes-Adams syndrome. + +There are, however, some cases, especially those with transudations, +when digitalis may be carefully tried even though high tension be +present. It is sometimes of advantage to combine digitalis with the +nitrites although they are said to be physiologically incompatible. + +Still another drug, that is of great value in conditions such as have +been described, is diuretin. This may be given in capsule or tablets, +grs. x. three times daily. There is only one caution to express in the +use of this drug. It should not be given when the kidneys are the seat +of chronic inflammatory changes; in fact, actual harm may be done by +administering the drug under such conditions. + +The same is true even to a greater extent with theocin. This is a +powerful diuretic. If given by mouth it should be well diluted as it is +most irritating to the stomach. It is best given intravenously in doses +of two and a half to three grains dissolved in five to six cubic +centimeters of distilled water. One must be reasonably sure that the +kidneys are not the subject of chronic disease and are functionally, +therefore, below par. The intravenous dose should not be given oftener +than once in four days. + +For the pain in aneurysm, nothing (except, of course, morphine) is so +valuable as iodide of potassium. Patients who are suffering agony, when +put to bed and given KI grs. x. three times a day, soon lose all the +distressing symptoms. This applies particularly to aneurysms of the arch +of the aorta. + +When the sclerosis has affected the cerebral arteries to such an extent +that symptoms result, the case is, as a rule, exceedingly grave. Not +much can be done except to relieve the headaches and keep down the blood +pressure, if this is high, by means of rest in bed, the iodides, +aconite, or the nitrites. The cases of transient monoplegias or +hemiplegias can be much relieved by careful hygienic measures and +judicious administration of drugs. Much ingenuity is sometimes required +to overcome the idiosyncrasies of patients, but care and patience will +succeed in surmounting all such difficulties. + +The treatment of intermittent claudication is the treatment of +arteriosclerosis in general. Sometimes the circulation in the affected +leg or legs is much helped by daily warm foot baths. Light massage might +be tried and the galvanic current may be used once or twice daily. + +There are a few distressing symptoms that occur usually late in the +disease, when complications have already occurred, which frequently +baffle the therapeutic skill of the physician. The chief of +these--insomnia, dyspnea, and headache--may not be late manifestations, +but insomnia and headache are frequently associated with the moderately +advanced stages of arteriosclerosis. At times all the symptoms seem to +be due to the high tension, the relief of which causes them to +disappear. There are, unfortunately, times when high tension is not +responsible for the headache and insomnia. Under these circumstances +such drugs as trional, veronal, amylene hydrate, ammonol, etc., may be +tried until one is found which produces sleep. For the headaches, +phenacetin, alone or in combination with caffein and bromide of sodium, +may be tried. Acetanilid, cautiously used, is at times of value. There +have been cases of arteriosclerosis with low blood pressure, accompanied +by severe headaches, that have been relieved by ergot. Codeine should be +used with care, and morphine only as a very last resource. + +Great care must always be exercised in giving drugs that depress the +circulation, for it is easily conceivable that more harm than good can +come from injudicious drugging. + + + + +CHAPTER XIV + +ARTERIOSCLEROSIS IN ITS RELATION TO LIFE INSURANCE + + +The value of the early recognition of cases of arteriosclerosis and +hypertension has been spoken of within, but it needs to be further +emphasized. There is perhaps no class among physicians to whom is +afforded a better opportunity of seeing early cases than the medical +examiners of life insurance companies. + +The relationship between a patient and the physician whom he consults, +and the applicant for life insurance and the examiner are diametrically +opposite. In the former the patient desires to conceal nothing and the +physician is called upon to diagnose and treat disease. In the latter +the applicant, a presumably healthy person, may have much to conceal and +the examiner is there to pass upon the state of health. The question is +this--"Is the applicant now in good health?" It becomes then of vital +importance for the examiner to be able to detect among other abnormal +conditions the incipient signs of arteriosclerosis and of hypertension. +Parenthetically it may be stated that arteriosclerosis and hypertension +are not one and the same disease as has been so frequently insisted upon +within; the former may occur without the latter but the latter can not +from its very nature be present for long without arterial thickening +supervening. It is necessary in discussing the question here to group +the two conditions together in order to prevent needless repetition. + +Such a case as the following is common. A successful business man of +forty-four years was brought to me by an agent in 1905 for examination. +The man was six feet tall, weighed 218 pounds, had a ruddy color and +looked to be the picture of health. He was not strictly intemperate, he +never became intoxicated, but every day he drank three or four whiskies +and often he had a bottle of wine for dinner in the evening. When he was +examined his pulse was of good quality and owing to the fleshiness of +the wrist it was difficult to say positively whether the radial artery +was sclerosed or not. In the heart no murmurs were heard, and it was +difficult to be sure that the left ventricle was enlarged. There was, +however, a slight but definite accentuation of the second sound at the +aortic cartilage which might readily have been overlooked had the +patient not been stripped and a careful examination made with the +stethoscope. Upon taking the blood pressure it was found to be from +170-175 mm. of Hg. The urine specimen examined at the visit was normal, +no casts were found. The applicant was seen at his home and the blood +pressure measured. It was again the same. He was seen a third time and +practically the same systolic blood pressure was found. Under protests +from all the agency staff the man was declined. Two years later he died +of apoplexy. The man was angry at being refused. Instead of looking the +matter squarely in the face he thrust aside the idea that there was +anything the matter with him. He had never had one ill day in his life, +his forebears had lived to ripe old age, and he was sure that he knew +more about himself than the examiner. + +Had this applicant showed a sense of reasonableness he should have been +grateful to the doctor for calling his attention to a condition which +surely would sooner or later prove either fatal itself or lead to some +fatal lesion. It was learned that this man had gone directly to his +family physician who laughed at such nonsense as had been told the (now) +patient by the examiner. + +Another illustration of a slightly different type of case is afforded in +the following history. + +A man of fifty years of age, five feet ten in height and 164 lbs. in +weight, was brought for examination. In his youth there was a history +of a mild attack of scarlet fever. He was almost a total abstainer, +rarely taking liquor in any form. Physically he appeared to be an +excellent risk. However, on examining the heart it was found that there +was slight hypertrophy with an accentuated second aortic sound at the +base, and the blood pressure was 180 mm. of Hg. Some sclerosis of the +radial arteries was found. One company had refused him on account of +albumin in the urine. There was none in the first specimen which was +passed while in the office. The specific gravity was 1014. A morning +specimen was obtained and contained a trace of albumin. Several +specimens were then examined. Some contained albumin, some had no +albumin content. The man was declined; no protests from the agent as +albumin had been found. There was something tangible in that. Had the +applicant been refused on account of his high tension, sclerosis of the +radials, and slightly enlarged heart there would undoubtedly have been +protests. And yet an applicant revealing such a state of the +cardiovascular system without albumin in the urine should unhesitatingly +be declined. Attention has been called to hypertension as an early, and +some think an invariable, sign of chronic nephritis. My own experience +has confirmed me in the belief that in hypertension the kidneys are +often the seat of chronic interstitial changes. Careful palpation of the +radial and brachial arteries will in every case reveal more or less +thickening. + +There is yet another group of cases which the examiner sees as healthy +subjects, namely those cases of sclerosis of the peripheral arteries +without sclerosis of the aorta and without high tension. In such cases +the radials, brachials, temporals and other superficial arteries are +readily palpable, sometimes even revealing irregularities along the +course of a vessel. Such cases are not subjects for insurance. The +recognition of such a condition is of great importance to the one who +has it and he should be urged to go to his regular physician for +thorough examination. Should the physician ridicule the idea, as has +happened to me more than once when I was actively engaged in insurance +work, the examiner has done his full duty to the company, the applicant, +and himself. + +A life insurance examiner has a difficult position to fill. He has four +people to satisfy; the applicant, the agent, the medical director and +himself. The straight and narrow path of strict honesty is his only +salvation. By being honest with himself he necessarily gives a square +deal to the other three parties. + +No applicant who has palpable arteries or hypertension can be considered +a first class risk. It can not be denied that men with arteriosclerosis +live to an advanced age and may even outlive those who have apparently +normal arteries, but the average life expectancy at any age for an +arteriosclerotic is less than that for a normal person. The apparently +healthy applicant who learns for the first time when examined for life +insurance that he has the early or moderately advanced signs of arterial +disease, should thank the agent and examiner for showing him the danger +signals ahead. The sensible man then orders his life so that he puts as +little strain on his heart, arteries, and kidneys as possible and may +add many years to his life. + +It is on account of this very insidiousness of onset that I have +elsewhere urged as a prophylactic measure the examination every six +months of all persons over forty years of age. I am more and more +convinced that it is of vital importance to the health of the public. + +As I have remarked, the average man consults his dentist at least once a +year so that no tooth may be so far diseased that it can not be saved. +It is purely a means of preserving the teeth. Why not do the same with +the whole body? Of what use is it to save the teeth and lose the body? +It seems to me that the great army of life insurance examiners are in an +enviable position in their ability to add years of life to many men and +women. I doubt whether they realize their importance in the campaign for +health. I should urge life insurance companies not to employ recent +graduates unless they have had at least a year's hospital experience. +For the company as well as for the individuals I believe that there is a +prognostic sense which the examiner should have and this can only be +acquired by experience. + +I believe that arteriosclerosis and hypertension are increasing for the +reasons which have been given in another chapter. There can be no doubt +that when these conditions are recognized long before symptoms would +naturally supervene, men and women would not only live longer but also +die more comfortably and many very likely would be carried off by some +disease having no relationship whatever to arteriosclerosis. Slight +enlargement of the heart downward and to the left, accentuation of the +second aortic sound at the base, a full pulse, arteries which are +palpably thickened, increased blood pressure are signs to which +attention must be paid. + +When the peripheral arteries are palpable they are not always sclerosed. +The radial artery, the one usually palpated, may lie very close to the +bone in a thin person. Under these conditions the artery can be easily +felt. It is better then to palpate for the brachial as it lies beneath +the inner edge of the biceps muscle. Should this artery be felt then +very probably sclerosis is present. Opinion as to whether or not +sclerosis is present, when it is slight, may differ. It is difficult at +times to say definitely. Should such be the case the applicant should be +most carefully questioned as to his family and past history, the heart +should be carefully outlined by percussion and the blood pressure should +be taken, both the systolic and diastolic pressures. The urine should be +examined with particular care. I am aware that the average examination +for life insurance is not made with the care which is bestowed upon a +patient. Yet I see no reason why the same attention to detail should +not be given in one as in the other. The examination of the great +majority of applicants can he made in a short time, as there is no +question of latent chronic disease. When the exception turns up he +should be given a searching examination and a full report should be sent +to the Medical Director. Only in this way will it be possible to weed +out the undesirable risks. + +On the surface it does not seem to require any great diagnostic acumen +to be a life insurance examiner. In the old days of many of the +companies there were no examiners. The applicant was brought before the +president or other appointed official and he was passed or rejected on +his general appearance. This has changed, and now the medical department +with its scores of examiners in the field is a well organized +department. + +It seems to me that the examiner should be an exceedingly able +diagnostician and prognosticator. There is no telling when he may be +called upon to pass judgment on a borderline case. From personal +experience I know how difficult it is to make a decision in some cases. +These suspicious cases after a careful examination had better be passed +by the examiner and a supplementary report sent to the medical director +containing unbiased details. But no applicant with readily palpable +arteries, even though the blood pressure be normal, should be considered +a first class insurance risk. + +The question of the value of the diastolic pressure reading in +examinations for life insurance is not yet settled to the satisfaction +of all medical directors. Certain medical directors with clinical +experience behind them, lay great stress on the increased diastolic +pressure and consider a persistent diastolic of 100 mm. really more +significant as an indication of hypertension than a systolic pressure of +160 mm. Other directors pay little or no attention to the diastolic +reading. Should an applicant show a systolic above the average normal on +several successive readings, he is declined. When one takes into +consideration the psychic effect of knowing that he is being examined +for high blood pressure, it seems unfair to refuse insurance on such +grounds as is constantly done. + +Up to the present there are no extensive series of life-expectancy +tables in which hundreds of thousands of cases are analyzed from the +diastolic pressure values. There are many such tables for the systolic +pressures alone. In the tabulation of such statistics one must not lose +sight of the important fact that the figures are taken by thousands of +men of varying capacity and different degrees of intelligence. Such +studies to be of any real value must be taken from records made at the +home offices by capable men. We shall await these tables with interest. +In the meantime we must be permitted to have the impression that the +diastolic pressure has been much neglected. This has no doubt been due +to the difficulty of measuring it with any degree of accuracy. Now with +the auscultatory method and the correct place to read the diastolic +pressure the results of blood pressure estimations should begin to have +some value for statistical data. + +Clinically the diastolic is probably more important than the systolic. +Until proof is brought to the contrary we shall believe that in life +insurance examinations it has the same importance. + + + + +CHAPTER XV + +PRACTICAL SUGGESTIONS + + +The time spent in obtaining a careful history of a case is time well +spent. Often the diagnosis can be made from the history alone, the +physical examination merely adding confirmation to the data already +obtained. + +The younger the patient who has arteriosclerosis, the more probable is +it that syphilis is the etiologic factor. A denial of infection should +have little weight if the history of possible exposure is present. +Miscarriages in a woman should arouse the suspicion of lues in her +husband. The complement-fixation reaction will often clear up an +apparently obscure diagnosis. + +There are various ways of examining a patient but there is only one +right way; the examination should be made on the bare skin. However +skillful one may be in the art of physical diagnosis, he can gather few +accurate data by examining over the clothes even if he use a +phonendoscope. + +The immoderate eater is laying up for himself a wealth of trouble at the +time when he can least afford to bear it. The ounce of advice in time is +worth more to him than the pounds of medicine later. + +It is a wise maxim never to drive a horse too far. Apply that to the +human being and the rule holds equally well. + +There may be no symptoms in a case of advanced arteriosclerosis. Do not +on that account neglect to advise a patient in whom the disease is +accidentally discovered. + +Many a man owes a debt of gratitude to the life insurance examiner. He +rarely feels grateful. + +When a competent ophthalmologist refers a case to a general practitioner +with the statement that he believes from the appearance of the fundus of +the eye that arteriosclerotic changes are present over the body, the +case should be most carefully examined. The earliest diagnoses are not +infrequently made by the ophthalmologist. + +It is the part of wisdom never to have such a firmly preconceived idea +of the diagnosis that facts observed are perverted in order to fit into +the diagnosis. Let the facts speak for themselves. + +Beware of the snap diagnosis. Even in a case of well-marked +arteriosclerosis when the diagnosis seems to be written in large letters +all over the patient, go through the routine. Nine times out of ten this +may seem needless. The tenth time it saves your conscience and +reputation. Always consider that you are examining a tenth case. + +Gradual loss of weight in a person over fifty years old should arouse +the suspicion of arteriosclerosis. + +Do not call the nervous symptoms displayed by a middle-aged man or woman +neurasthenia until you have ruled out all organic causes, particularly +arteriosclerosis. + +When palpating the radial artery, always use both hands according to the +method already described. Pay attention to the superficial or deep +situation of the artery. + +The examination of one specimen of urine does not give much information, +especially if it should be found to contain no abnormal elements. Fairly +accurate data may be gathered from the mixed night and morning urine; +most accurate data from the twenty-four hour specimen. To be of any real +value there should be frequent examinations of the day's excretion. + +In measuring the day's output a good rule is as follows: begin to +collect urine after the first morning's micturition and collect all +including the first quantity passed the next morning. It is best to +examine the centrifugated urine for casts even though no albumin be +present. It is useless to look for casts in an alkaline urine. + +Casts are not infrequently found in chemically normal urine from a +middle-aged patient. Other things being normal, the finding has no +significance. The kidneys must be carefully tested functionally. + +Blood pressure readings should always be taken with the patient in the +same posture at every estimation. At the first examination it is +advisable to take readings from both brachial arteries. Let the patient +sit comfortably and relax all muscles. + +Differentiate as soon as possible between the uncompensated heart caused +by valvular disease and that caused by arteriosclerosis. There is a +difference in prognosis. Both give the same symptoms, and are treated +similarly until compensation returns; thereafter the management of the +two forms is different. + +Aortic incompetence that comes on late in life is generally the result +of curling of the free margins of the valves caused by syphilitic +arteriosclerosis. Prognosis is grave because of the fact that the heart +muscle also is the seat of degenerative changes and compensatory +hypertrophy is established with difficulty. + +When laying down a regime for a patient, consider his disposition, and +individualize the treatment. Remember that exercise is an essential +feature of the hygiene of the patient's life but do not forget to be +explicit about the amount and character of the permissible exercise. + +In the prophylaxis of arteriosclerosis, a rational mode of living is the +all-important factor. As a rule, the less meat one eats, the less is the +liability of arterial degeneration as age advances. The exceptions to +this rule are many, and probably depend upon the character of the "vital +rubber" with which the individual begins life. + +The diet in well-marked cases of arteriosclerosis should be carefully +selected with regard to its nutritive and non-irritating character. +Animal proteins should be sparingly used. Milk should have an important +place in the dietary. + +No drug relieves the pain of uncomplicated aneurysm as surely as iodide +of potassium. + +Iodides frequently upset the stomach. Be cautious in the use of them. +The irritable stomach may turn the scales against your patient. + +Use cardiac stimulants with care and judgment. If all the valuable +ammunition is used up at first, the fight will be lost. + +Use digitalis with especial care. Its chief usefulness is in steadying +the decompensated heart, improving the conduction of impulses, and +increasing the tone of the cardiac muscle. _It should never be given to +patients with very slow pulses, the subjects of Stokes-Adams syndrome._ +Digitalis has been found to produce partial to complete heart block when +therapeutically administered. + +Remember that in the uncompensated heart morphine not only eases the +oppressive dyspnea, but also steadies and stimulates the heart. + +See to it that the patient has a daily movement of the bowels. In the +early stage try the effect of liquid paraffin or of the mineral waters +such as Pluto, or Hunyadi Janos, or artificial Carlsbad salts (Sprudel +salts). These last can be made as follows: Sodium chloride, ounce I; +sodium bicarbonate, ounce II; sodium sulphate, ounce IV. Take two +tablespoonsful of this in a glass of hot water before breakfast. Should +these not succeed, assist the action of the drugs by the use of enemata. +The pill of aloin, strychnine sulphate, and extract of cascara, with the +addition of a small quantity of hyoscyamus, is a mild tonic purgative. +In cases of constipation with high tension, there is no drug as valuable +as calomel or one of the other mercurials given occasionally. + +Never give Epsom salts unless copious watery stools are desired to +deplete effusion into the serous cavities or into the subcutaneous +tissue. + +Chronic constipation increases the gravity of the prognosis. + +In case of suppression of urine and anasarca, hot air packs may be of +value. The patient may be wrapped in a hot wet sheet and covered with +blankets. I do not believe in administering pilocarpine to assist the +sweating. + +Remember to treat the patient and not the disease. The careful hygienic +and dietetic treatment, combined with the least amount of drugging, is +the best and most rational method of treatment. + + + + +INDEX + + + A + + Abdominal symptoms, 201 + + Aconite in treatment, 242 + + Acquired arteriosclerosis, 159 + + Adami, effect of syphilis in aorta, 45 + + Adventitia, 28 + + Age in arteriosclerosis, 161 + + Albuminuria, 221 + + Albutt's classification of arteriosclerosis, 186 + + Alcohol, 166, 228, 235 + + Anatomy, 25 + + Angina abdominalis, 201, 216 + pectoris, 197, 216 + pseudo, 216 + + Angiosclerosis, 26, 64 + + Aorta, 27 + anatomical lesions in, 33 + Aschoff on, 35 + normal, 41 + syphilis in, 44 + thoracic, 29 + thoracic and abdominal, arteriosclerosis of, 39 + velocity of blood in, 66 + + Aortic incompetence, 61, 258 + stenosis, 60 + + Aortitis, acute, 165 + + Arcus senilis, 191 + + Arrhythmia, tonal, 92, 102 + + Arterial pressure, 85 + symptoms, 189 + + Arteries, 29 + examination of, 172, 177 + general structure of, 27 + large, 30 + adventitia of, 30 + palpable, 189 + pulmonary, arteriosclerosis of, 63 + + Arteriocapillary fibrosis, 26 + + Arteriosclerotic endocarditis, 60, 219 + + Artery, coronary, cross-section of, 36 + pulmonary, 209 + radial, 29 + + Aschoff on aorta, 35 + + Atheroma, simple, 32 + + Atheromatous abscess, 38 + + Auricular fibrillation, 133 + flutter, 131 + + Auscultation, 176 + + Auscultatory blood pressure phenomenon, 90 + method of taking blood pressure, 83 + percussion, 175 + + + B + + Balneotherapy, 233 + + Basch's blood pressure instrument, 70 + + Blood, circulation of, 65 + velocity of, 65 + in animals, 66 + in aorta, 66 + in capillaries, 66 + viscosity of, 68 + + Blood pressure, 68 + auscultatory method of taking, 83 + clinical applications of, 147 + diurnal variations of, 102 + drugs influencing, 120 + estimation of, 179 + in cancer, 118 + in collapse, 118 + in exercise, 105 + in head injuries, 148 + in hemorrhages, 105, 118, 148 + in infectious diseases, 153 + in kidney diseases, 155 + in meningitis, 118 + in obstetrics, 152 + in pulmonary tuberculosis, 119 + in shock, 105, 148 + in surgery, 147 + in typhoid fever, 118, 154 + in valvular heart disease, 155 + increase of, 55 + instruments, 70 + Brown's, 74 + Cook's, 71 + Erlanger's, 72 + Faught's, 75, 80 + Hill and Barnard's, 70 + Hirschfelder's, 73 + K. Vierordt's, 70 + Marcy's, 70 + Potain's, 70 + Riva Rocci's, 70 + Roger's, 77 + Sanborn's, 80 + Stanton's, 72 + technique of, 80 + "Tycos," 77 + v. Basch's, 70 + v. Recklinghausen's, 76 + mechanism of, 55 + normal variations of, 88 + phenomenon, auscultatory, 90 + precautions when estimating, 181 + value of, 181 + + Bowman's capsules, sclerosis of, 62 + + Brain, changes in, 62 + + Brown atrophy, 60, 118, 201 + + + C + + Calcification of media, 43, 59 + + Cancer, blood pressure in, 118 + + Capillaries, anatomy of, 27, 31 + + Capillary pulse, 67 + + Cardiac dullness, 172 + irregularities in arteriosclerosis, 131 + symptoms, 195 + + Cerebral symptoms, 203 + + Circulation of blood, 65 + physiology of, 65 + + Cirrhosis of liver, 64, 216 + + Classification of arteriosclerosis, 32, 37 + Allbutt's, 186 + + Collapse, blood pressure in, 118 + + Congenital arteriosclerosis, 157 + + Cook's blood pressure instrument, 71 + + Cor bovinum, 116 + + Coronary artery, cross section of, 36 + + Corpus luteum, 241 + + + D + + Definition of arteriosclerosis, 26 + + Diabetes mellitus, 216 + + Diagnosis, 210 + differential, 215 + early, 210 + ophthalmic examination in, 214 + + Diastolic pressure, 69, 83, 85, 94 + importance of, 97 + + Dicrotic pulse, 123 + + Dietetic treatment, 235 + + Differential diagnosis, 166, 215 + + Diffuse arteriosclerosis, 32, 37, 38, 57 + + Digitalis in treatment, 246, 259 + + Diuretin in treatment, 246 + + Drug intoxications, 166 + + Drugs influencing blood pressure, 105, 120 + + Ductless glands, 171 + + Dullness, cardiac, 172 + + Dyspeptic symptoms, 184 + + Dyspnea, 184 + treatment of, 248 + + + E + + Electrocardiogram, 126 + + Embolism, 59 + + Endarteritis deformans, 47 + obliterans, 46 + + Endocarditis, arteriosclerotic, 60, 219 + + Endothelial lining, 27 + tubes, 31 + + Epistaxis, 184, 221 + + Erlanger's blood pressure instrument, 72 + + Erythromelalgia, 192, 208 + + Estimation of blood pressure, 179 + + Etiology, 157 + + Examination of arteries, 172, 177 + of heart, 172 + of urine, 257 + + Exercise, blood pressure in, 105 + in prophylaxis, 225 + in treatment, 230 + + Experimental arteriosclerosis, 50 + + Extrasystole, 138 + + + F + + Faught's blood pressure instrument, 75, 80 + + Fibrillation, auricular, 133 + ventricular, 138 + + Fibrolysin in treatment, 243 + + Fingernail palpation, 178 + + Finger tip palpation, 179 + + Flutter, auricular, 131 + + Food poisons in arteriosclerosis, 163 + + + G + + Gibson's law, 154 + + + H + + "H" wave, 126 + + Habits, personal, 234 + + Head injuries, blood pressure in, 148 + + Headache, 184 + treatment of, 248 + + Heart block, 140 + boundaries, 172 + examination of, 172 + hypertrophy of, 60 + physical examination of, 172 + stimulants, 243, 246, 259 + symptoms, 188 + + Hemorrhages, blood pressure in, 118 + + Henle, membrane of, 29 + + Hill and Barnard's blood pressure instrument, 70 + + Hirschfelder's blood pressure instrument, 73 + + His, bundle of, 141, 197 + + Hygienic treatment, 230 + + Hyperpietic arteriosclerosis, 186 + + Hypertension, 60, 106, 169, 185, 249 + cause of arteriosclerosis, 159 + classification of cases, 112 + + Hypertrophy of left ventricle, 58 + + Hypotension, 117 + + + I + + Incompetence, aortic, 61, 258 + + Indicanuria, 167 + + Infants, arteriosclerosis in, 158 + + Infectious diseases in arteriosclerosis, 163 + blood pressure in, 153 + + Insomnia, treatment of, 248 + + Intermittent claudication, 192, 208 + treatment of, 247 + + Intoxications, chronic drug, 166 + + Intracranial tension, 105 + + Involutionary arteriosclerosis, 187 + + Iodides in treatment, 238, 247, 259 + + + K + + Kidney diseases, blood pressure in, 155 + + Kidneys, sclerosis of, 61, 170 + + + L + + Life insurance, relation to, 249 + + Light percussion, 174 + touch palpation, 175 + + Liver, cirrhosis, 64, 216 + + Local symptoms, 207 + + + M + + Marey's blood pressure instrument, 70 + + Maximum pressure, 85, 94 + + Mean pressure, 85 + + Media, calcification of, 43, 59 + + Medicinal treatment, 238 + + Meningitis, blood pressure in, 118 + + Mental strain, 168 + + Mesaortitis, 45, 47, 49, 165 + + Mesentery, cross-section of small artery in, 56 + + Milk diet, 237 + + Minimum pressure, 86, 94 + + Moenckeberg type of arteriosclerosis, 43 + + Morphine in treatment, 243 + + Mosenthal test meal, 221 + + Muscular overwork, 169 + + + N + + Nervous symptoms, 191 + + Nitrites in treatment, 240 + + Nitroglycerin in treatment, 241 + + Nodular arteriosclerosis, 32, 37 + + Normal blood pressure variation, 88 + + + O + + Obstetrics, blood pressure in, 152 + + Occupation in arteriosclerosis, 162 + + Ocular symptoms, 190 + + Ophthalmic examination, importance in early diagnosis, 214, 256 + + Orthodiagraph, 173 + + Overeating, 167, 212, 225, 235 + + Overwork, muscular, 169 + + + P + + "P" wave, 129 + + "P-R" interval, 130 + + Palpable arteries, 189 + + Palpation, 174, 180 + fingernail, 178 + finger tip, 179 + light touch, 175 + + Pathology, 32 + + Percussion, 174 + auscultatory, 175 + light, 174 + + Peripheral symptoms, 207 + + Personal habits, 234 + + Phlebosclerosis, 64 + + Phthalein test, 221 + + Physical signs, 183 + + Physiology of the circulation, 65 + + Potain's blood pressure instrument, 70 + + Practical suggestions, 256 + + Pressure, arterial, 85 + ausculatory method of determining, 83 + diastolic, 83, 94 + estimation of, 179 + in surgery, 147 + maximum, 85, 94 + normal variations, 88 + pulse, 83, 85, 87, 100 + systolic, 82, 85 + technique, 80 + venous, 120 + + Prognosis, 218 + + Prophylaxis, 224 + exercise in, 225 + + Pseudo angina pectoris, 216 + + Pulmonary artery, 209 + arteriosclerosis of, 63 + tuberculosis, blood pressure in, 119 + + Pulse, 123 + capillary, 67 + deficit, 135 + dicrotic, 123 + in arteriosclerosis, 123 + pressure, 69, 83, 85, 87, 100 + rate, 69 + venous, 123 + + Purgatives in treatment, 244, 259 + + Pyrosis, 184 + + + Q + + "Q R S" complex, 129 + + + R + + Rabbits, lesions produced experimentally in, 50 + + Race in arteriosclerosis, 161 + + Radial artery, 29 + + Radials, sclerosis of, 43 + + Raynaud's disease, 192, 207 + + Recklinghausen's blood pressure instrument, 76 + + Renal disease, 169 + symptoms, 199 + + Rest in treatment, 242 + + Riva-Rocci's blood pressure instrument, 70 + + Rogers' blood pressure instrument, 77 + + + S + + Sanborn's blood pressure instrument, 80 + + Scaphoid scapula, 158 + + Schwellungsperkussion, 174 + + Sclerosis of veins, 64 + + Senile arteriosclerosis, 32, 37, 43, 59 + + Sex in arteriosclerosis, 161 + + Shock, blood pressure in, 105, 148 + + Spinal symptoms, 205 + + Spirochaeta pallida, 45 + + Stanton's blood pressure instrument, 72 + + Stenosis, aortic, 60 + + Stokes-Adams syndrome, 197 + + Stomach, ulcer of, 216 + + Strain hypertrophy, 47, 54, 55 + + Surgery, blood pressure in, 147 + + Symptomatic treatment, 245 + + Symptoms, 183 + abdominal, 201 + arterial, 189 + cardiac, 195 + cerebral, 203 + dyspeptic, 184 + dyspnea, 184 + general, 183 + headache, 184 + heart, 188 + local, 207 + nervous, 191 + ocular, 190 + peripheral, 207 + pyrosis, 184 + renal, 199 + special, 194 + spinal, 205 + vertigo, 184 + visceral, 201 + + Syphilis, 165 + in aorta, 44 + + Syphilitic arteriosclerosis, 37 + + Systolic pressure, 69, 82, 85, 94 + importance of, 97 + + + T + + "T" wave, 130 + + Technique of blood pressure instruments, 80 + + Thayer and Fabyan, 34 + + Theocin, 247 + + Thoma on arteriosclerosis, 33 + + Thoracic aorta, 29 + + Thyroid extract in treatment, 239 + + Tobacco, 167, 212, 234 + + Tonal arrhythmia, 92, 102 + + Toxic arteriosclerosis, 186 + + Treatment, 229 + aconite in, 242 + balneotherapy in, 233 + corpus luteum, 241 + dietetic, 235 + digitalis in, 246, 259 + diuretin in, 246 + exercise in, 230 + fibrolysin in, 243 + heart stimulants in, 243 + hygienic, 230 + iodides in, 238, 247, 259 + medicinal, 238 + morphine in, 243 + nitrites in, 240 + nitroglycerin in, 241 + of dyspnea, 248 + of headache, 248 + of insomnia, 248 + of intermittent claudication, 247 + personal habits in, 234 + purgatives in, 244, 259 + rest in, 242 + symptomatic, 245 + theocin in, 247 + thyroid extract in, 239 + Trunecek's serum in, 243 + venesection in, 242 + veratrum viride in, 242 + + Trunecek's serum in treatment, 243 + + Tuberculosis, blood pressure in, 119 + + Tunica intima, 28 + media, 28 + + "Tycos" blood pressure instrument, 77 + + Typhoid fever as cause of arteriosclerosis, 164 + blood pressure in, 118 + + + U + + Ulcer of stomach, 216 + + Urine, examination of, 257 + suppression of, 259 + + + V + + Valvular heart disease, blood pressure in, 155 + + Vasa vasorum, 29 + + Veins, anatomy of, 30 + sclerosis of, 64 + + Velocity of blood in animals, 66 + of blood in aorta, 66 + + Venesection in treatment, 242 + + Venous pressure, 120 + pulse, 123 + + Ventricle, left, hypertrophy of, 58 + + Ventricular fibrillation, 138 + + Veratrum viride in treatment, 242 + + Vertigo, 184 + + + * * * * * + + +Transcriber's Notes: Irregular hyphenation has been preserved, as in +blood pressure and blood-pressure. Both "Hg" and "Hg." appear. + +Minor typographical errors and inconsistencies have been silently +normalized. + +The original printed list of illustrations shows the original +locations; they have been moved closer to their discussion area +in the text to not interrupt the flow of reading. + +Page 244 Prescription symbol is replaced with R_{x} + +Page 259 Apothecaries ounce symbol replaced with "ounce" + + + + + +End of the Project Gutenberg EBook of Arteriosclerosis and Hypertension:, by +Louis Marshall Warfield + +*** END OF THIS PROJECT GUTENBERG EBOOK ARTERIOSCLEROSIS AND HYPERTENSION: *** + +***** This file should be named 37675.txt or 37675.zip ***** +This and all associated files of various formats will be found in: + http://www.gutenberg.org/3/7/6/7/37675/ + +Produced by Bryan Ness, Julia Neufeld and the Online +Distributed Proofreading Team at http://www.pgdp.net (This +file was produced from images generously made available +by The Internet Archive/American Libraries.) + + +Updated editions will replace the previous one--the old editions +will be renamed. + +Creating the works from public domain print editions means that no +one owns a United States copyright in these works, so the Foundation +(and you!) can copy and distribute it in the United States without +permission and without paying copyright royalties. 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