Showing papers in "Circulation in 1965"
TL;DR: The present understanding of these hereditary defects is meager and their classification chaotic, and when one is concerned particularly with familial hyperlipoproteinemia, necessitating screening of large kindreds, neither of these approaches has proved ideal.
Abstract: IT HAS been well established that the lipids in plasma do not circulate free but combine in orderly arrangements with protein. Most of the lipid is combined with two major proteins, the a and ,3 polypeptides, to form lipoproteins that extend over a wide density range, from greater than 1.21 to that of fat itself, about 0.9 Gm. per ml. Changes in this lipoprotein spectrum occur in many diseases. In many instances the lipoprotein abnormality appears to be the primary expression of a biochemical defect. These disorders are usually familial, relatively common, and of particular interest in relation to atherogenesis and coronary heart disease. Despite their relative importance, the present understanding of these hereditary defects is meager and their classification chaotic. For the determination and study of such abnormalities a number of methods have been available for some time. The minimum is a determination of plasma cholesterol and glyceride content. The maximum in resolving power is offered by the ultracentrifuge, which is capable of measuring changes within small increments of the density spectrum. When one is concerned particularly with familial hyperlipoproteinemia, necessitating screening of large kindreds, neither of these approaches has proved ideal. Measurement of triglyc-
461 citations
TL;DR: The effects of sublingual nitroglycerin and inhaled amyl nitrite on the arteriolar and venous beds of the forearm were studied and venoconstriction was abolished or diminished when adrenergic activity was impeded by administration of either guanethidine or reserpine.
Abstract: The effects of sublingual nitroglycerin and inhaled amyl nitrite on the arteriolar and venous beds of the forearm were studied in 11 normal subjects. Forearm blood flow was measured with a strain-gauge plethysmograph, and venous tone was determined both by an acute occlusion technic, and by several equilibration technics. Nitroglycerin reduced systemic arterial pressure, elevated forearm blood flow, lowered forearm vascular resistance and decreased venous tone. Amyl nitrite diminished arterial pressure, elevated forearm blood flow, markedly decreased forearm vascular resistance, but in contrast to nitroglycerin augmented venous tone strikingly. This venoconstriction was abolished or diminished when adrenergic activity was impeded by administration of either guanethidine or reserpine.
451 citations
332 citations
TL;DR: In this paper, the tracings were classified according to the system of Blackburn and associates and various categories are tabulated and discussed, including abnormal Q waves and certain "nonspecific" changes such as left axis deviation, high-amplitude R waves, ST-segment depression, T-wave inversion, first-degree atrioventricular block, complete intraventricular block, and arrhythmias increased in frequency with age.
Abstract: Electrocardiograms were recorded from 2,449 men and 2,689 women past 16 years of age, 85 per cent of the adult population of Tecumseh, Michigan. The tracings were classified according to the system of Blackburn and associates and the various categories are tabulated and discussed. Abnormal Q waves and certain "nonspecific" changes such as left axis deviation, high-amplitude R waves, ST-segment depression, T-wave inversion, first-degree atrioventricular block, complete intraventricular block, and arrhythmias increased in frequency with age. Hypertension and hyperglycemia occurred with significant frequency among persons with some of these changes. It seems likely that such "nonspecific" electrocardiographic abnormalities are frequently signs of coronary or hypertensive heart disease. The mean amplitudes of QRS complexes of men less than 50 years of age were greater than those of women. Such sex differences should be taken into account in the interpretation of clinical electrocardiograms. Further examinatio...
316 citations
TL;DR: These studies indicate that in the absence of augmented metabolic requirements, homeostatic mechanisms maintain cardiac output relatively constant despite large induced changes in the heart rate, however, when metabolic demands are increased by muscular exercise, or the circulation is stimulated by catecholamines, cardiac output can rise through an increase in stroke volume, even when alterations in theheart rate are prevented.
Abstract: A technic is described for controlling the heart rate in patients with normal atrioventricular conduction by means of an electrical pacemaker catheter that stimulated the right atrium. When the heart rates of 17 patients in the resting state were elevated from an average of 80 to 121 beats/min., the cardiac indices remained virtually unchanged and averaged 3.67 and 3.72 L./min./M.2, respectively. Further increases in the heart rates resulted in small reductions in the cardiac indices to an average value of 3.21 L./min./M.2 at 148 beats/min. The stroke volumes, ejection periods, and mean rates of ejection decreased as heart rate was increased. The role of heart rate in the circulatory response to exercise was examined in seven patients. When the heart rates were controlled by electrical stimulation at rates comparable to those previously achieved spontaneously during exercise, it was observed that cardiac output rose normally with exercise and that this rise was accomplished entirely through an increase in...
266 citations
TL;DR: The present study suggests that, in the absence of pulmonary hypertension, a left-to-right transatrial shunt associated with systemic arterial oxygen desaturation may indicate the presence of a persistent left superior vena cava terminating in the left atrium.
Abstract: Eight cases of termination of the left superior vena cava in the left atrium are reviewed pathologically and clinically. In three of the five patients who died, pathologic examination revealed three anomalies which, together, are considered to form a developmental complex. The anomalies are (1) termination of the left superior vena cava in the left atrium, (2) absence of the coronary sinus, and (3) an atrial septal defect lying in the postero-inferior angle of the atrial septum. In the two remaining fatal cases, the aforementioned anomalies were associated with persistent common atrioventricular canal. In this situation, the atrial septal defect of the latter malformation was confluent with the atrial septal defect of the anomalous complex described. The coexistence of three anomalies-the left superior vena cava terminating in the left atrium, absent coronary sinus, and atrial septal defect-is considered to result from a single developmental abnormality. This takes the form of failure of complete formatio...
262 citations
TL;DR: Calcified lesions were most prevalent and most extensive in the left anterior descending branch and occurred with greatest frequency at 2 to 3 cm.
Abstract: Measurements of the per cent of the surface with calcified lesions have been made for the three main coronary arteries from 1,242 consecutive necropsies of whites and Negroes between the ages of 30 to 69 years. Calcified lesions were most prevalent and most extensive in the left anterior descending branch and occurred with greatest frequency at 2 to 3 cm. from the orifice. Whites had greater involvement than Negroes and males had greater involvement than females. Prevalence and extent of calcification have been compared in four cause-of-death or disease categories; cases dying of coronary heart disease had greater involvement than the other three groups. The prevalence of ischemic myocardial lesions, complicated coronary lesions, or stenotic lesions was greater for cases with calcified lesions, and this prevalence increases with increase in extent of calcified lesions. The significance of the presence of coronary calcified lesions for the diagnosis of advanced coronary atherosclerosis is greatest for younger individuals.
231 citations
TL;DR: In this article, the clinical course of nine patients, aged 14 to 49, who either at surgery or autopsy demonstrated myxomatous valvular transformation, has been described.
Abstract: The clinical course of nine patients, aged 14 to 49, who either at surgery or autopsy demonstrated myxomatous valvular transformation, has been described. Five females presented with symptomatic mitral insufficiency. Two of them had had endocarditis whereas in the others a heart murmur was detected during childhood. Three of the four men had a recent onset of aortic insufficiency associated in one case with aneurysm of the ascending aorta. The fourth experienced sequential arterial rupture and finally aortic dissection, his asymptomatic valvular lesion becoming manifest only at autopsy. The electrocardiographic, roentgenographic, angiographic, and catheterization findings resembled those seen in rheumatic heart disease, except that neither fibrosis, calcification, nor stenosis was found. The histologic appearance of the valve leaflets was identical to that which has been described, primarily as an incidental lesion, in the Marfan syndrome. Only one of the nine patients, however, demonstrated arachnodactyl...
228 citations
TL;DR: Cardiorespiratory variables measured during attempts at cardiac resuscitation in 11 patients are presented and cardiac index and stroke index were significantly better with the internal method, and the mean circulation time was significantly shorter.
Abstract: Cardiorespiratory variables measured during attempts at cardiac resuscitation in 11 patients are presented. These were obtained ten times during closed-chest massage and 15 times during open-chest massage. Three patients were studied during both techniques of resuscitation. Cardiac index and stroke index were significantly better with the internal method, and the mean circulation time was significantly shorter.
227 citations
TL;DR: The encouraging result obtained in this patient suggests that in selected instances, valve excision and replacement under antibiotic coverage provide a possible therapeutic approach to certain difficult cases of active bacterial endocarditis.
Abstract: This report describes a 45-year-old man who developed acute bacterial endocarditis involving the aortic valve due to Klebsiella type 19. Consequent to the infection the patient developed aortic insufficiency and congestive heart failure. The patient failed to respond adequately to antibiotic therapy alone and rapid clinical deterioration required that the aortic valve be replaced despite the presence of active infection. Excision of the aortic valve appears to have removed the site of infection and replacement with a Starr prosthesis has corrected the aortic insufficiency. The patient has been followed for 15 months since the operative procedure, during which time he has returned to his work as a bricklayer. The encouraging result obtained in this patient suggests that in selected instances, valve excision and replacement under antibiotic coverage provide a possible therapeutic approach to certain difficult cases of active bacterial endocarditis.
204 citations
TL;DR: Isoproterenol infusions increased the rate and degree of left ventricular emptying, obliterating portions of the cavity earlier andincreasing the pressure gradient as mentioned in this paper, which was similar to the phenome-non observed in dogs receiving isopronylinone infusions.
Abstract: Summary and Conclusions Significant outflow tract obstruction was notseen byleft ventricular cineangiocardiography in seven patients with "hypertrophic subaorticstenosis."Catheter withdrawals through the leftventricle, recorded cinefluorographically, lo-calized the high pressure areas to portions ofthe left ventricle which emptied completely in early systole. Sustained systolic contractionin empty portions of the left ventricle pro-vides an explanation for the pressure gradi-entsinthesepatients.Isoproterenol infusions increased the rate and degree of left ventricular emptying, ob-literating portions of the cavity earlier andincreasingthepressure gradient.Themechanismof gradient production with- out obstruction was similar to the phenome-non observed in dogs receiving isoproterenol infusions. The cardiac muscle in these patients is ab-normally thick and the left ventricle emptiesmorerapidly than normal; therefore a "hyper- trophic hyperkinetic cardiomyopathy" is present.The nonobstructive
TL;DR: The purpose of this presentation is to report a prospective study of 50 cases with adequate hemodynamic characterization of the typical physical findings and to demonstrate a diagnosis based on positive rather than eliminative approach.
Abstract: JT is perhaps accurate to state that every clinician has witnessed cases of marked cardiomegaly with failure, generally in men, for which no specific etiology could be found after careful clinical, laboratory, and even postmortem examinations. It is with this type of heart disease that this report is concerned. Authors writing on this subject have used innumerable terminologies to describe the disease. Most of the terms imply the myocardial localization of the pathologic process. In this presentation the term \"primary myocardial\" is used to indicate an obscure etiology as well as a purely myocardial localization of the disease process. Such infiltrative and degenerative myocardial processes as amyloidosis, sarcoidosis, hemochromatosis, and thyroid heart disease have therefore been excluded. Our method of case selection resembles that of Fowler et al.I and Dye et al.2 but is more restrictive than the method used by Brigden,3 Goodwin et al.,4 and also by Mattingly, the originator of the term \"primary myocardial disease.\" 5, 6 The purpose of this presentation is to report a prospective study of 50 cases with adequate hemodynamic characterization of the typical physical findings and to demonstrate a diagnosis based on positive rather than eliminative approach. The following historical review will serve to place the disease in proper perspective in relation to other myocardial processes.
TL;DR: The findings have been interpreted as providing further support for the propositions that manifestations of myocardial insufficiency do occur in very obese subjects without evidences of other heart disease, that these manifestations are those of predominant left ventricular or biventricular failure, and that isolated cor pulmonale does not develop in the absence of pulmonary embolization.
Abstract: Appraisal of the gross and microscopic anatomy of the heart was carried out at necropsy in 12 subjects (six men, six women) with marked chronic obesity. In each case the observed heart weight was considerably greater than that predicted at ideal body weight. Nine of the 12 subjects were found to have increase in left ventricular wall thickness, and two increase in right. The increases in heart weight and ventricular wall thickness were due to muscle hypertrophy involving the left ventricle or both left and right ventricles. Neither isolated nor predominant right ventricular hypertrophy was observed. It has been concluded that myocardial hypertrophy is a more specific and significant anatomic alteration in the hearts of very obese subjects than are the previously reported findings of excess epicardial fat and fatty infiltration of the myocardium. The relationship between chronic augmentation of the work of the heart in these subjects and the development of cardiac hypertrophy has been discussed. The findin...
TL;DR: Because the pressure changes are easy to monitor and parallel the other features of the hemodynamic reaction, it is good to wait until pressures have returned to the pre-angiographic level before proceeding with the injection of more radiopaque material.
Abstract: The hemodynamic changes resulting from injection of radiopaque material into the left heart in a series of patients undergong cineangiographic studies have been reported. The hypertonicity of radiopaque materials appears to be responsible for much of the observed reaction. The mechanism whereby hypertonic solutions produce the observed physiologic changes remains unknown. Changes observed in patients could be reproduced in experimental animals. The combined experimental and clinical data show that left atrial pressure increases, left atrial pulse contour alters, stroke output increases, heart rate is much unchanged, peripheral artery pressure falls, hematocrit level falls, and myocardial contractile force decreases mildly and transiently. The difference between the physiologic effects of injecting hypertonic media into the right and left sides of the circulation is discussed. Because the pressure changes are easy to monitor and parallel the other features of the hemodynamic reaction, it is good to wait un...
TL;DR: The presentation was oriented to stress topics of special value to the physician dealing with patients having heart disease.
Abstract: This is a brief perspective review of some personal observations on the normal and abnormal anatomy of the human coronary arteries. Since it is possible to cover in detail but a few aspects of such a broad subject, the presentation was oriented to stress topics of special value to the physician dealing with patients having heart disease.
TL;DR: It is ironic that Richard Lower, who did so much in his day to liberate medicine from medieval dogma, should himself be the origin of a dogma for later generations, for the Lower schemata fail to be accurate or useful.
Abstract: N EARLY three hundred years ago (1669) in his book Tractus de Corde, Richard Lower offered the first detailed description of the muscular anatomy of the ventricle.l* His drawings show separate overlapping layers, rather like the layers of an onion, each layer consisting of differently directed muscle fibers. Since his day, many anatomists, perhaps most definitively Mall,3 have repeated his dissections and have altered his schemata only in details. As a result, today the illustrations of ventricular myocardial architecture in all anatomy textbooks are essentially elaborations of Lower's original drawings. Yet, for generations, medical students (and more recently cardiac surgeons) have compared with dismay the textbook illustrations of the heart with the organ they hold in their hands, for no such layers are to be seen. It is ironic that Lower, who did so much in his day to liberate medicine from medieval dogma, should himself be the origin of a dogma for later generations. The reason why the Lower schemata fail to be accurate or useful is related to the fact that the only conceptual tool available to him in his day was plane geometry. As he expressed in his Tractus, \".according to Geometry's laws, the straight line is the guide to the
TL;DR: Twelve patients were reverted from atrial fibrillation to sinus rhythm by the technic of “cardioversion,” brief, light anesthesia was the only drug employed and cardiac output was measured under conditions of comparable oxygen consumption.
Abstract: Twelve patients were reverted from atrial fibrillation to sinus rhythm by the technic of "cardioversion." Brief, light anesthesia was the only drug employed. Under conditions of comparable oxygen consumption cardiac output was measured first in atrial fibrillation and then in sinus rhythm. Eleven patients were studied at rest and five during exercise. Ten of the 11 patients studied at rest showed a reduced arteriovenous oxygen difference with sinus rhythm and seven of the 11 increased cardiac output 0.6 L./min. or greater, an average increase of 34 per cent. All five patients studied at exercise decreased the arteriovenous oxygen difference with sinus rhythm and cardiac output rose 1.1 L./min. or greater in all, an average increase of 17 per cent.
TL;DR: In this article, a review of the consecutive autopsy series of three hospitals over a period of 13 years was conducted to determine whether there is a notable change in incidence of cardiac rupture and to re-evaluate underlying factors.
Abstract: SINCE the first description of rupture of the heart by William Harvey in 1647, this dramatic termination of life has attracted the attention of clinicians and pathologists alike. The anatomist Morgagni,' whose own life ended at the age of 79 with this disease, collected 10 cases in 1765. By 1928, 734 cases had been culled from the world literature by Davenport2 and subsequently many more reviews and case reports have been added.3-5 At the present time, there are conflicting factors that tend to alter the relative incidence of rupture of the heart. On one hand, with increased awareness and diagnostic facility in the recognition of acute myocardial infarction, one might expect the over-all incidence of rupture as well as other fatal complications to be reduced. On the other hand, because of the improved outlook for the acutely ill patient, shielded from fatal arrhythmias and cardiac standstill by pharmacologic or electrical stabilization, sustained in shock with vasopressors, and protected from thromboembolism by anticoagulants, the relative incidence of cardiac rupture among fatal cases might increase. In order to determine whether there is a notable change in incidence of rupture and to re-evaluate underlying factors, the consecutive autopsy series of three hospitals were reviewed over a period of 13 years.*
TL;DR: The effect of valvular insufficiency on left ventricular volumes was studied by an angiographic method in 37 patients and results show good agreement with subsequent surgical findings in the 15 patients who underwent operation.
Abstract: The effect of valvular insufficiency on left ventricular volumes was studied by an angiographic method in 37 patients. Ejection of the additional volume load imposed by valvular insufficiency was achieved by an increase in end-diastolic volume and not by increasing the proportion of end-diastolic volume ejected. Of the 37 patients, 16 (43 per cent) had a significant reduction in the fraction of end-diastolic volume ejected per beat. These patients performed significantly less stroke work from a given end-diastolic fiber length (end-diastolic volume) than did the others and evidence is presented that they had impaired myocardial function. An index of myocardial contractility is derived which relates stroke work to end-diastolic volume. The magnitude of left ventricular volumes is determined in part by the severity of the volume load but a further increase in volume without necessarily a further increase in ejection occurs in those patients with impaired myocardial function. Valvular insufficiency is quanti...
TL;DR: The graded exercise test, using 85 per cent of the maximal age-predicted heart rate that may be induced by exercise, produces a closer approximation of a standardized cardiac stress, regardless of age, sex, or body build.
Abstract: Standardization of an exercise electrocardiographic test for myocardial ischemia is desirable. Standardization of exercise should be based upon a standardized challenge to the coronary circulation, not upon a standardized challenge to the skeletal muscles, for the stresses upon the heart are not identical. With the use of heart rate during exercise as an index of cardiac stress, the levels of exercise prescribed on the basis of age, sex, and weight in standard "two-step" test tables produce widely varying levels of cardiac stress-sometimes too low to induce significant ST-segment depression in patients with angina pectoris and, occasionally, much greater than necessary to produce such diagnostic electrocardiographic changes. The graded exercise test, using 85 per cent of the maximal age-predicted heart rate that may be induced by exercise, produces a closer approximation of a standardized cardiac stress, regardless of age, sex, or body build. Its use with angina pectoris patients and normal subjects resul...
TL;DR: The reasons for the variations of the refractory period at different levels of the AV junction as a result of concealed conduction are analyzed and may readily account for the over-all irregularity of the ventricular response associated with atrial fibrillation.
Abstract: The ventricular response in atrial fibrillation is determined by the long refractory period of the AV junction. Since an atrial impulse is always available for transmission to the ventricles, a regular ventricular rhythm would be expected, the rate of which would reflect the duration of a stable junctional refractory phase. The irregularity of the ventricular action associated with atrial fibrillation, therefore, indicates changes of refractoriness of the AV junctional tissues from cycle to cycle. This can best be attributed to varying degrees of penetration of "blocked" atrial impulses into parts of the AV junction, and to the effect of such concealed conduction on the propagation of subsequent impulses. The following facts are pointed out and illustrated as evidence of concealed AV and VA conduction during atrial fibrillation: (a) Occurrence of a "compensatory pause" following a ventricular premature systole. (b) Failure of an AV nodal escape to appear at the expected time due to concealed discharge of ...
TL;DR: Subaortic stenosis is a complicated subject and may be represented by a primary anomaly of the left ventricular outflow tract or may be secondary either to conditions primary in the mitral valve or to generalized diseases of the myocardium.
Abstract: Lesions causing obstruction to the outflow of blood from the left ventricle may reside in the ascending aorta, the aortic valve, or the outflow tract of the left ventricle. Conditions involving the ascending aorta are usually congenital, and designated as supravalvular aortic stenosis. A tendency is present for this condition to be associated with mental retardation, stenosis of peripheral pulmonary arteries, stenosis of branches of the aortic arch, and a peculiar facies. Secondary narrowing of coronary arteries may occur. Obstruction at the aortic valve is usually represented by a stenotic lesion. In some instances, the basis for stenosis is congenital; in others, it is acquired either through the direct effects of rheumatic endocarditis or through calcification of an acquired or congenital bicuspid aortic valve. Atresia of the aortic valve causes death in infancy. Subaortic stenosis is a complicated subject. It may be represented by a primary anomaly of the left ventricular outflow tract or may be secon...
TL;DR: In this paper, the effects on ventricular dimensions of intact, unanesthetized patients of isoproterenol, a drug that stimulates beta adrenergic receptors, and of methoxamine, an agent that stimulates alpha adrenergic receptor, were studied by means of a cineradiographic technic.
Abstract: The effects on ventricular dimensions of intact, unanesthetized patients of isoproterenol, a drug that stimulates beta adrenergic receptors, and of methoxamine, an agent that stimulates alpha adrenergic receptors, were studied by means of a cineradiographic technic. The administration of isoproterenol to 13 patients consistently resulted in a decline in the end-systolic dimensions of both ventricles. A smaller and less consistent decrease in ventricular end-diastolic dimensions was noted. In contrast, the administration of methoxamine resulted in an increase of ventricular end-diastolic dimensions in all 10 patients studied. Left ventricular end-systolic dimensions increased during methoxamine infusion in the eight patients in whom the measurements were made, but changes in right ventricular end-systolic dimensions were inconsistent. The alterations in heart rate induced by isoproterenol and methoxamine could account only in part for the observed changes in ventricular dimensions. It is anticipated that the experimental approach used in this study, that is, the measurement of ventricular dimensions in intact, unanesthetized human subjects, will help to provide a more complete analysis of the action of drugs on the circulation of man.
TL;DR: In severe fixed hypertension blood volume, cardiac output, and peripheral resistance were found to be high, and Renal ischemia and secondary hyperaldosteronism may determine the development of this last stage of hypertension.
Abstract: Hemodynamic studies, including cardiac output, arterial blood pressure, run-off index, flow cessation pressure, and blood volume, were performed in 20 normotensive control subjects, 17 labile hypertensive patients and 20 patients with fixed hypertension, 10 of them with a mild elevation of the diastolic pressure and 10 classified as severe because of a diastolic blood pressure above 110 mm. Hg. In labile hypertension cardiac output was elevated, whereas blood volume, peripheral resistance, run-off index and flow cessation pressure were normal when blood pressure was high. This hemodynamic pattern was interpreted as due to an enhanced myocardial contractile energy or a restriction of the capacity vascular bed. In mild fixed hypertension total peripheral resistance and flow cessation pressure were uniformly increased, but cardiac output and run-off index were normal. This pattern may be explained by the influence of flow autoregulation and the barostatic mechanism. In severe fixed hypertension blood volume,...
TL;DR: Examples in VI of ventricular extrasystoles whose form resembled an R BBB pattern, actual RBBB, and aberrant ventricular conduction of RBBBs type were scrutinized.
Abstract: TO THE untutored Western eye, the faces of oriental gentlemen are strikingly alike. In a similar way, most of us are unable to distinguish at sight between the QRS-T pattern of bundle-branch block and the ectopic ventricular complex that simulates it. Yet the morphologic distinction could be of practical importance, since, especially in thpresence of atrial fibrillation, it is often impossible by any other means to distinguish ectopic ventricular beats from aberrant ventricular conduction. Aberrant conduction is of little concern in either prognosis or treatment, whereas the presence of ventricular ectopic activity may significantly influence both. Since the great majority of aberrant beats show right bundle-branch block (RBBB), this pattern is of prime importance. One promising approach to distinguish the Chinese from the Japanese from the Filipino would be to line up a number of each and empirically scan their features for generic differences. With the oriental gentlemen in mind, we decided to muster and scrutinize examples in VI of ventricular extrasystoles whose form resembled an RBBB pattern, actual RBBB, and aberrant ventricular conduction of RBBB type.
TL;DR: The clinical, radiologic, morbid anatomic, and histologic features of six cases of annular subvalvular left ventricular aneurysms occurring in African subjects are described and the possibilities of antemortem diagnosis discussed.
Abstract: The clinical, radiologic, morbid anatomic, and histologic features of six cases of annular subvalvular left ventricular aneurysms occurring in African subjects are described. The problems of surgical repair are emphasized and the possibilities of antemortem diagnosis discussed.
TL;DR: The cardiovascular response to angiographic contrast medium was studied in patients undergoing diagnostic angiocardiography under anesthesia, and Hemodilution, maximal 2 to 4 minutes after injection of contrast medium, suggested a transient increase in circulating blood volume.
Abstract: The cardiovascular response to angiographic contrast medium was studied in 28 patients undergoing diagnostic angiocardiography under anesthesia. A transient phase of hypotension and tachycardia similar to that described by other authors was noted. Cardiac output was increased initially by 50 per cent and returned to the base line in 20 minutes. Peripheral blood flow increased by 100 per cent, apparently due to the direct effect of the hyperosmotic solution on the vascular smooth muscle. Hemodilution, maximal 2 to 4 minutes after injection of contrast medium, suggested a transient increase in circulating blood volume. Increased ventricular filling pressures, which were thought to be due to hypervolemia, were associated with increased left ventricular stroke work.
TL;DR: The theory that angina pectoris came about as the result of myocardial ischemia, usually in the presence of intraluminal coronary artery disease or disease causing cardiac hypertrophy, and elicited by disturbance of the balance between coronary oxygen supply and myocardIAL oxygen demand is concluded.
Abstract: ANGINA pectoris can be no better described than in Heberden's original discussion some 160 years ago.' Despite the enduring quality of his description, Heberden had no idea of the cause of angina pectoris, although he did appreciate its morbid quality. In the same era, Jenner, Parry, and Burns were among the first clinicians to associate angina pectoris with anatomic disease of the coronary arteries. This notion lost favor somewhat during the latter half of the nineteenth century when anginal pain was thought to originate in spasm of the coronary arteries or in disease of the aortic wall itself.2 The twentieth century witnessed the observations of Herrick,3 MacKenzie,4 Levine,5 Keefer and Resnik,6 and Blumg-art, Schlesinger, and Davis,7 culminating in the theory that angina pectoris came about as the result of myocardial ischemia, usually in the presence of intraluminal coronary artery disease or disease causing cardiac hypertrophy, and elicited by disturbance of the balance between coronary oxygen supply and myocardial oxygen demand. The purpose of this report is to indicate what new facts may be added to these masterful disser;tations. The discussion is divided into three parts: mechanism of pain excitation within the heart; myocardio-neuronal reception and transmission of pain impulses; clinico-physiologic factors in the development of angina pectoris.
TL;DR: During a stress-induced anginal attack, the rise, if any, in systolic ejection rate of the left ventricle, was markedly decreased below that achieved in normal subjects or in subjects with coronary artery disease without angina.
Abstract: Sixteen patients developed angina pectoris during cardiac catheterization. During an anginal attack, left ventricular end-diastolic pressure did not uniformly rise. When it did occur, it seemed to be more closely related to acute left ventricular hypertension. During a stress-induced anginal attack, the rise, if any, in systolic ejection rate of the left ventricle, was markedly decreased below that achieved in normal subjects or in subjects with coronary artery disease without angina. The impaired augmentation in systolic ejection rate was associated with subnormal increases in cardiac output as well as in stroke volume during the anginal state. Average heart rate and systolic ejection period were no different from the nonanginal patients. Myocardial excess lactate was found in the vast majority of cases during an anginal episode, and actual myocardial lactate production was seen in one half of the patients during angina. The abnormalities in left ventricular function may be related to abnormalities in oxygen supply to the myocardium.
TL;DR: The concept of a progressive expansion of a fistula of slow or rapid development permitting more and more blood to be shunted or sequestered in a shorter parasitic circuit at very rapid or very slow rates of increase provides the long-sought explanation of the rapid or long-delayed development of cardiac dilatation and failure in the presence of a peripheral fistula.
Abstract: Clinical experiences and experimental studies provide evidence that an abnormal communication between the arterial and venous systems introduces into the circulation two circuits of flowing blood, one characterized by high arterial pressure and high peripheral resistance, and a second system bypassing part of the first, thus introducing a shorter circuit back to the heart, characterized by low pressure and low resistance, each supplied with flowing blood from the same central source, the heart. This shorter circuit acts solely as a parasitic circuit engrafted upon the normal circulation, serving no useful purpose, but capable of producing serious deleterious effects, depending upon the volume of blood diverted from the normal circulation into the shorter or parasitic circuit. Intimately dependent upon this diversion of differing volumes of blood into the shorter circuit is the great diversity in the effects of a peripheral fistula upon the heart: the complete absence of cardiac dilatation in some cases; t...