bluuebunny/crossref_metadata_2025 huggingface dataset:
An Angiocardiographic Analysis of the Thickness of the Left Ventricular Wall and Cavity in Aortic Stenosis and Other Valvular Lesions
Authors: LEVINE NORMAN D. , ROCKOFF S. DAVID , BRAUNWALD EUGENE
Published: June 2012

In order to provide information concerning changes in the width of the left ventricular cavity and the thickness of the left ventricular wall in patients with various forms of heart disease, relatively simple measurements were carried out on angiocardiograms exposed during diastole in the frontal projection. The diameter of the left ventricular cavity and the thickness of the free wall of the left ventricle were measured in a standardized manner in 57 patients, in all of whom the diagnosis had been established. In patients with valvular or discrete subvalvular aortic stenosis, the thickness of the free wall of the left ventricle was usually greater than in patients without abnormalities of the left ventricle, and the degree of thickening correlated closely with the degree of obstruction. This type of correlation was not present in patients with hypertrophic subaortic stenosis. No increase in the width of the left ventricular cavity was noted in patients with obstruction to left ventricular outflow. In patients with aortic or mitral regurgitation, the width of the left ventricular cavity tended to be increased without any consistent increase in the thickness of the left ventricular wall. The measurements described are simple enough to be applied routinely in order to provide information concerning the effects of various forms of heart disease on the gross structure of the left ventricle during life.
Five Years' Experience with the Evaluation of Diuretic Agents
Authors: SWARTZ CHARLES , SELLER ROBERT , FUCHS MORTON , BREST ALBERT N. , MOYER JOHN H.
Published: June 2012

Twelve diuretics and 2 combinations of diuretics were evaluated by a standard methodology. Electrolyte excretion patterns were evaluated in "normal" hospitalized patients, and acute weight loss was evaluated in out-patients in congestive failure. The large standard errors of the means for natriuresis, kaluresis, and acute weight loss reflect the inherent biologic variation of such assays and permit separation of drugs into only a few overlapping categories of potency. The combination of a mercurial and a thiazide caused significantly greater sodium excretion than any other drug used alone. No single diuretic was significantly more potent than all others.
Persistent Truncus Arteriosus
Authors: TANDON RAJENDRA , HAUCK ANNA J. , NADAS ALEXANDER S.
Published: June 2012

The clinical, hemodynamic, and autopsy data on 19 patients with a diagnosis of persistent truncus arteriosus have been presented.

A proposed clinical classification, dividing the patients into types I and II only, with exclusion of type IV, provides a uniform clinical profile. The patients, as a rule, are small infants with a large left-to-right shunt, minimal cyanosis, wide pulse pressure, left or combined ventricular hypertrophy, and congestive heart failure, and resemble patients with a ventricular septal defect or patent ductus arteriosus.

At cardiac catheterization distinct but slight differences in pressures or saturations between pulmonary arteries and "ascending aorta" do not exclude the diagnosis of persistent truncus arteriosus.

The prognosis is uniformly poor. Most infants die in congestive heart failure within the first 6 months of life, others develop pulmonary vascular obstructive disease in later years.
P-Wave Analysis in Valvular Heart Disease
Authors: MORRIS JAMES J. , ESTES E. HARVEY , WHALEN ROBERT E. , THOMPSON HOWARD K. , MCINTOSH HENRY D.
Published: June 2012

Electrocardiographic analysis of the P waves occurring in a series of 113 normal subjects and 100 patients with specifically defined valvular lesions are reviewed. The former methods of analysis showed a marked lack of specificity.

By dividing the P wave in lead V
1
into initial and terminal portions, a measure designated as the P terminal force has been derived. This measure is of value in two respects: (1) it correctly separates normal subjects from those patients with left-sided valvular lesions in 92 per cent of this series and (2) once a given valve lesion is suspected clinically, this measure enables one to make an estimation of the severity of that lesion from the degree of abnormality of the P terminal force at V
1
. The P terminal force does not indicate the type of valvular disease present, nor does it correlate with any one specific hemodynamic measure. The abnormality does appear to be related, within each separate type of valve disease, to the specific hemodynamic abnormality of that type of valvular involvement.

The anatomic and electrophysiologic changes that might relate to these P-wave changes are discussed.
Carcinoid Heart Disease with Left-Sided Lesions
Authors: SCHWEIZER W. , GLOOR F. , BERTRAB R. V. , DUBACH U. C.
Published: June 2012

A case of carcinoid heart disease investigated during life and after death is described.
Anomalous Inferior Vena Cava Draining into the Left Atrium Associated with Intact Interatrial Septum and Multiple Pulmonary Arteriovenous Fistulae
Authors: BLACK HARRISON , SMITH GEORGE T. , GOODALE WALTER T.
Published: June 2012

A 30-year-old woman with cyanotic heart disease due to anomalous drainage of the inferior vena cava into the left atrium in the presence of an intact interatrial septum is reported. The diagnosis was established during life and the defect was successfully corrected by open-heart surgery. The patient failed to survive due to associated multiple pulmonary arteriovenous fistulae. The embryology of the intracardiac defect, the pathophysiology of these fistulae, and the associated advanced pulmonary atherosclerosis are discussed.
Transient Bundle-Branch Block
Authors: BAUER G. E.
Published: June 2012

Fourteen patients with transient bundle-branch block have been personally studied. All but one suffered from ischemic heart disease commonly accompanied by hypertension. The conduction defect was observed to appear during acute infarction, attacks of prolonged chest pain, and episodes of left ventricular failure. Not infrequently, however, the appearance and disappearance of bundle-branch block was unaccompanied by any recognizable change in the patient's physical condition.

Bundle-branch block may revert to normal intraventricular conduction after many years. In one patient bundle-branch block disappeared on three separate occasions after having been present for over 12 months. Another patient is described in whom normal conduction returned after left bundle-branch block had been established for a record duration of 6 years.

The etiology, prognosis, and pathogenesis of transient bundle-branch block have been discussed and the practical importance of this conduction defect in the electrocardiographic diagnosis of myocardial infarction is mentioned.
Idiopathic Hypertrophic Subaortic Stenosis: II. Operative Treatment and the Results of Pre- and Postoperative Hemodynamic Evaluations
Authors: MORROW ANDREW G. , LAMBREW COSTAS T. , BRAUNWALD EUGENE
Published: June 2012

In 10 of 64 patients with IHSS, operations designed to relieve obstruction were performed. The pertinent preoperative clinical and hemodynamic findings in these patients, the operative methods employed, and the results of operation are presented in the present report.

Eight of the patients were males, 2 were females, and at the time of operation their ages ranged from 10 to 54 years. All of the patients were symptomatic and all but 2 were in functional classes III and IV. In each patient left heart catheterization proved the presence of left ventricular outflow obstruction and the peak systolic gradients between the left ventricle and a systemic artery ranged from 68 to 175 mm. Hg (average 110 mm. Hg). The effective orifice areas ranged from 0.44 to 0.99 cm.
2
(average 0.61 cm.
2
). Pulmonary hypertension was present in 2 patients.

In 5 patients simple left ventriculomyotomy was performed, and in the other 5 ventriculomyotomy was combined with resection of a portion of the hypertrophied interventricular septum. One patient, in whom operative pressure measurements indicated satisfactory relief of obstruction, died suddenly on the eighth postoperative day, apparently from arrhythmia. Complete heart block was produced in 2 patients, and these patients have implanted pacemakers. Seven of the 9 surviving patients have been followed for periods of 7 to 51 months, and each has had striking symptomatic improvement. Left heart catheterizations have been carried out postoperatively on one or more occasions in all 7 patients. In 6 no intraventricular pressure gradient was present at rest or during exercise, while in the remaining patient a peak gradient of 24 mm. Hg was evident.

The pertinent clinical findings in these 10 patients, the operative methods utilized, and the results of their pre- and postoperative hemodynamic assessments are presented in detail. Consideration is also given to present concepts in the selection of patients for operation, and in the choice of operative techniques.
Serum Lipids and Conjunctival Circulation after Fat Ingestion in Men Exhibiting Type-A Behavior Pattern
Authors: FRIEDMAN MEYER , ROSENMAN RAY H. , BYERS SANFORD , Carroll Vernice , Hayashi Warren , King Marshon , Omoto Clarence , Tam Ashley
Published: June 2012

A group of 12 subjects exhibiting a behavior pattern A, associated with a high incidence of clinical coronary artery disease, and a second group of subjects exhibiting a converse type of behavior pattern B, were fed a standard fat meal, before and after which studies were made of serum lipid and cholesterol changes. In addition, studies were made of their bulbar conjunctival vasculature.

It was found that the average fasting serum triglyceride, cholesterol, and phospholipid values of the "A" subjects were significantly greater than those of the "B" subjects. Following the meal, the average serum triglyceride rose much higher and remained relatively much higher and longer in subjects with pattern A than in those with pattern B. The serum free fatty acid content was essentially the same in both groups, both before and after the meal. The observed differences in serum triglyceride behavior did not appear to be due to differences in the circulating phase of the heparininduced lipoprotein-lipase system.

Following the meal, marked sludging and capillary ischemia were found in the conjunctival tissue of 10 or 12 subjects with pattern A and in only three of the 12 subjects with pattern B.
Controlled Myocardial Injury Produced by a Hypothermal Method
Authors: TAYLOR C. BRUCE , DAVIS C. B. , VAWTER GORDON F. , HASS GEORGE M.
Published: June 2012

Following a review of experimental methods used for the production of necrosis or inactivation of the myocardium, a new method employing low temperatures is described. Lesions, with complete necrosis of muscle cells, can be controlled as to size and can be selectively placed to involve any of the four cardiac chambers and the interventricular septum. This facilitates attempts to study chronic myocardial insufficiency in terms of quantity and location of damaged muscle. Also, it has been possible to produce disturbances in conduction by production of small interventricular septal lesions. Refined electrocardiographic analysis of the magnitude and location of ventricular lesions has not been possible.
Pathology of the Pulmonary Vascular Tree
Authors: EDWARDS JESSE E. , CHAMBERLIN WILLIAM B.
Published: June 2012

The pulmonary vessels in 2 cases of cor triloculare with subaortic stenosis are compared. Each showed medial hypertrophy of the muscular arteries of the lungs. In 1 case concerning an 8 year old boy this class of vessels showed, in addition, severe intimal fibrosis. The arterioles were normal.

It is emphasized that the changes in the pulmonary arteries are similar to those seen in the Eisenmenger complex, in coarctation of the aorta proximal to a patent ductus arteriosus and in the normal fetus. These conditions, though anatomically different from each other and from cor triloculare with subaortic stenosis, are functionally alike in that there is in each a common ventricular ejectile force for the pulmonary and the systemic circulations in the absence of stenosis in the major arterial pathways to the lungs.

It is suggested that in cor triloculare biatriatum with subaortic stenosis, the structure of the pulmonary muscular arteries is, and that their function seems, similar to that of the fetus. The changes in the case of the malformation may be considered a carry-over from fetal life.
On Evaluating the Einthoven Triangle Theory
Authors: BUTTERWORTH J. SCOTT , THORPE JOHN J.
Published: June 2012

The authors have attempted to treat a controversial subject in a different way by introducing a known potential into the cavity of the living human heart and determining the magnitude of this potential at the extremities. While the data may be subject to various interpretations it is suggested that this technic may be a valuable tool for further analysis of the spread of potentials in the body.
Diagnostic Value of the First and Second Derivatives of the Arterial Pressure Pulse in Aortic Valve Disease and in Hypertrophic Subaortic Stenosis
Authors: MASON DEAN T. , BRAUNWALD EUGENE , ROSS JOHN , MORROW ANDREW G.
Published: June 2012

The brachial arterial dp/dt was continuously computed by means of an electronic differentiating circuit in 117 patients and 23 normal subjects. The peak dp/dt averaged 1092±372 (S.D.) mm. Hg/sec. in 32 patients with idiopathic hypertrophic subaortic stenosis, 547±94 mm. Hg/sec. in six patients with discrete subvalvular subaortic stenosis, 811±185 mm. Hg/sec. in 23 normal subjects, 358±85 mm. Hg/sec. in 29 patients with valvular aortic stenosis, 724±212 mm. Hg/sec. in 25 patients with combined aortic stenosis and regurgitation, and 1736±530 mm. Hg/sec. in 24 patients with pure aortic regurgitation. It is suggested that the elevated peak dp/dt seen in patients with hypertrophic stenosis is due to the absence of obstruction to ejection early in systole. In contrast, patients with valvular and discrete subvalvular stenosis, who exhibit fixed obstruction to outflow throughout ventricular systole, had a peak dp/dt that tended to be lower than normal. Calculation of the second derivative (d
2
p/dt
2
) of the arterial pressure pulse provided even better separation of the various groups of patients studied. The analyses of the dp/dt and of the d
2
p/dt
2
of the brachial artery pressure pulse afford a simple and reliable assessment of the nature and location of left ventricular outflow obstruction and are helpful in the differentiation of valvular aortic stenosis, combined stenosis and regurgitation, and pure aortic regurgitation.
Aneurysm of the Membranous Septum with Interventricular Septal Defect Producing Right Ventricular Outflow Obstruction
Authors: DAS SUNIL K. , JAHNKE EDWARD J. , WALKER WELDON J.
Published: June 2012

The second known case of aneurysm of the membranous interventricular septum simulating infundibular pulmonic stenosis associated with an interventricular septal defect is described. Hemodynamic studies before and after successful surgical correction of both lesions are presented. The current literature on the subject is briefly reviewed.
Congenital Communications of the Right Pulmonary Veins with the Azygos Vein
Authors: ANDERSON HOWARD N. , GUNTHEROTH WARREN G. , WINTERSCHEID LOREN C. , MERENDINO K. ALVIN
Published: June 2012

A case of total pulmonary venous drainage of the right lung into the azygos vein, surgically corrected, has been reported.

There have been 10 previous cases of varying degrees of partial right, total right, to total (bilateral) pulmonary venous drainage into the azygos vein. The authors' case is the third to be diagnosed during life and apparently the first case to be successfully corrected. With one exception, all previously reported cases have occurred in females.

A review of previous cases and surgical considerations in the authors' case have been presented.
The Relationship between Human Endocardial Fibroelastosis and Obstruction of the Cardiac Lymphatics
Authors: KLINE IRWIN K. , MILLER ALBERT J. , PICK RUTH , KATZ LOUIS N.
Published: June 2012

Two patients with marked ventricular endocardial fibroelastosis and evidence of obstruction of cardiac lymphatic vessels lend support to the hypothesis derived from dog experiments that chronic impairment of the cardiac lymph flow leads to endocardial fibroelastosis. One patient, aged 52 years, developed chronic myocarditis 7 years prior to her death. The other patient, a 6-month-old infant, had congenital lymphangiectasis with diffuse involvement of the gastrointestinal tract, lymph nodes, and heart. Microscopic examination of the hearts revealed markedly dilated and tortuous lymphatic channels throughout the myocardium and epicardium, a finding present with long-standing obstruction to lymph flow. It is concluded that chronic obstruction of cardiac lymph flow, from whatever cause, results in ventricular endocardial fibroelastosis.
The Corrected Orthogonal Electrocardiogram and Vectorcardiogram in 510 Normal Men (Frank Lead System)
Authors: DRAPER HAROLD W. , PEFFER CATHERINE J. , STALLMANN FRIEDEMANN W. , LITTMANN DAVID , PIPBERGER HUBERT V.
Published: June 2012

Corrected orthogonal electrocardiographic records were taken from 510 normal male subjects. Their age ranged from 19 to 84 years. Data processing and analysis were performed by means of a digital computer. Measurements were taken from the three scalar orthogonal leads and from a variety of spatial vectors in a Cartesian reference frame. Main emphasis was put on series of instantaneous vectors of the QRS complex, the ST segment, and the T wave. In order to eliminate inter-individual variability in electrocardiographic wave durations, time normalization was applied by dividing QRS, ST, and T into equal parts in time. Results for instantaneous vectors were also obtained in absolute time at intervals of 0.01 second. In addition, time integrals, polar vectors, and Eigenvectors were determined for P, QRS, and T. Normal ranges were computed for both normally and abnormally distributed results.
A Method for Measuring Plasma Levels of Digitalis Glycosides
Authors: LOWENSTEIN JEROLD M.
Published: June 2012

A method is described for measuring plasma levels of cardiac glycosides, utilizing their inhibitory effect on the rubidium-86 uptake of human red cells. As little as 0.05 mµg. of digoxin/ml. of plasma produces detectable inhibition, but due to the variable effect of other substances in human plasma the practical limit of the method is 1.0 mµg./ml., about 20 times as sensitive as the duck embryo heart or the C
14
-labeled technics.

Patients on digitalis leaf were found to have much higher circulating levels than patients on digoxin (average value 7.5 mµg./ ml. of digoxin equivalent for digitalis leaf, 0.05 mµg./ml. for digoxin). Patients toxic on digoxin averaged 6 mµg./ml.

Of patients not taking digitalis, 7 per cent had significant levels of digitalis-like substances in their plasma; these were mostly individuals with metastatic carcinoma, severe fluid and electrolyte disturbances, or heart failure. No drug (other than cardiac glycosides) gave consistent high levels by this test.
Myocardial Function and Left Ventricular Volumes in Acquired Valvular Insufficiency
Authors: MILLER GRAHAM A. H. , KIRKLIN JOHN W. , SWAN H. J. C.
Published: June 2012

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 quantitated from the difference between left ventricular ejection volume determined angiographically and forward stroke volume determined from indicator-dilution curves. The results show good agreement with subsequent surgical findings in the 15 patients who underwent operation.
Annular Subvalvular Left Ventricular Aneurysms in the South African Bantu
Authors: CHESLER ELLIOT , JOFFE NORMAN , SCHAMROTH LEO , MEYERS ANTHONY
Published: June 2012

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.
The Effect of Nitroglycerin on Left Ventricular Wall Tension in Fixed Orifice Aortic Stenosis
Authors: PERLOFF JOSEPH G. , RONAN JAMES A. , DE LEON ANTONIO C.
Published: June 2012

Symptoms of myocardial ischemia occur in aortic stenosis in the absence of coronary artery disease. Increased left ventricular wall tension, a principal determinant of myocardial oxygen requirements, may contribute to these symptoms. This investigation was undertaken during the course of transseptal left heart catheterization in order to study the effect of nitroglycerin on left ventricular wall tension in eight patients with fixed orifice aortic stenosis. In seven of the subjects, nitroglycerin significantly reduced tension-time index per beat and per minute. In addition, left ventricular size may have diminished as a consequence of lower diastolic filling pressure. In view of the relationship between wall tension and myocardial oxygen consumption, these effects should favorably influence the balance between oxygen availability and oxygen requirements in patients with fixed obstruction to left ventricular outflow. The eighth patient experienced an appreciable increase in tension-time index, suggesting secondary hypertrophic subaortic stenosis.
Chronic, Massive Thrombotic Obstruction of the Pulmonary Arteries
Authors: MOSER KENNETH M. , HOUK VERNON N. , JONES ROBERT C. , HUFNAGEL CHARLES C.
Published: June 2012

Four patients with extensive, chronic pulmonary arterial thrombotic obstruction, are presented in whom thromboendarterectomy was attempted. The procedure was successful in two, both of whom are alive and well more than 2 years since surgery; it was unsuccessful in two, both of whom succumbed in the postoperative period. The clinical and laboratory diagnostic approach to such patients is discussed. Criteria for selection of operative candidates are reviewed and certain technical decisions considered. It is concluded that selected patients with chronic massive occlusion can be improved significantly by thromboendarterectomy, but further experience is required to improve criteria for the selection of surgical candidates. The poor experience with two patients in advanced right ventricular failure already has indicated that one essential factor in reducing surgical risk is diagnosis prior to overt cardiac decompensation.
Experimental Demonstration of Concealed AV Conduction in the Human Heart
Authors: LANGENDORF R. , PICK A. , EDELIST A. , KATZ L. N.
Published: June 2012

Artificial pacing of patients with Stokes-Adams disease provided an opportunity to study experimentally the ways of operation of concealed antegrade or retrograde conduction, or both, in the AV junction.

With a catheter electrode in the right atrium the classical experiment of Lewis and Master was repeated, revealing, during a 2:1 ventricular response to an atrial tachycardia, the delaying effect of seemingly blocked atrial impulses on subsequent AV conduction.

Shifting the position of a single premature atrial impulse within a constant driving cycle of the atria produced graded effects of "blocked" atrial impulses on AV junctional refractoriness, permitting an estimation of the duration of the "phase of concealed AV conduction."

Interpolation of such premature atrial impulses into successive driving cycles resulted in "repetitive concealed conduction."

In an artificially produced atrial parasystole there was observed "concealed discharge" of a subsidiary (escaping) AV junctional pacemaker by an apparently nonconducted atrial impulse.

With a catheter electrode in the right ventricle in a case of advanced AV block, concealed retrograde conduction of pacer stimuli disturbed the rhythmicity of a spontaneous AV junctional pacemaker.

In a case of advanced AV block with preserved retrograde conduction (unidirectional block), evidence of penetration of the upper AV junction by the "blocked" antegrade impulse was found.

With electrodes implanted in the left ventricle in a case of advanced AV block, concealed retrograde conduction of the artificial pacemaker stimuli enhanced antegrade conduction by transiently changing an area of unidirectional block to one of supernormal conduction.

Thus, all known manifestations of concealed atrioventricular and ventriculo-atrial conduction, occurring spontaneously in clinical records or induced in animal experiments, were artificially reproduced in the human heart.
The Pathogenesis of Transient Focal Cerebral Ischemia
Authors: MILLIKAN CLARK H.
Published: June 2012

The pathogenesis of certain types of focal cerebral ischemia, particularly episodes of focal cerebrovascular insufficiency, is not fully understood. Atherosclerosis, a relatively static process, commonly occurs without producing any neurologic phenomena. However, such episodes rarely occur in cerebral vascular systems unaffected by atherosclerosis. Atherosclerosis plus some transitory pathophysiologic event would explain the clinical events. A list of such events includes vasospasm, transitory systemic hypotension, kinking and external compression of vessels, transitory hypoglycemia, temporary shunts, and thrombosis and multiple emboli. The roles of polycythemia and anemia are mentioned. Evidence is presented that incriminates thrombosis or embolus formation (or both) as the process, secondary to atherosclerosis or associated with atherosclerosis, that produces the focal cerebral ischemia.
Red Blood Cell Survival in Patients with Aortic Valvular Disease and Ball-Valve Prostheses
Authors: BRODEUR MICHAEL T. , SUTHERLAND DONALD W. , KOLER ROBERT D. , STARR ALBERT , KIMSEY JEAN A. , GRISWOLD HERBERT E.
Published: June 2012

Red blood cell survival was determined in patients with aortic valvular disease, postoperative patients with aortic valvular ball-valve prostheses and postoperative patients with multiple ball-valve prostheses. The red blood cell survival was reduced in the majority of patients in each group when compared with the red blood cell survival from a normal control group.

A detailed analysis of the survival curves suggested that in many patients there was more than one population of red blood cells. The first population displayed rapid random destruction. This population was not present in normal persons in the control group. The second population showed the usual decline in radioactivity due to random destruction and loss of the red cell label due to elution. The shortened red blood cell survival in some patients was due to a large percentage of the first population of randomly destroyed red blood cells, in other patients to an accelerated rate of destruction of the usual single population of cells while others had a combination of the two mechanisms.

A mechanism of mechanical hemolysis due to increased intracardiac turbulence was suggested as a cause for the shortened survival. When the turbulence was increased by a leak around the aortic or mitral valve prosthesis the red blood cell survival was found to be further decreased. In some cases this reduction in survival was enough to produce hemolytic anemia.

The Coombs antiglobulin test was positive in three patients. The suggestion was made that the development of autoantibodies to red blood cells was secondary to increased destruction of red blood cells.
Exercise Graded by Heart Rate in Electrocardiographic Testing for Angina Pectoris
Authors: SHEFFIELD L. T. , HOLT JOHN H. , REEVES T. JOSEPH
Published: June 2012

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 results in increased sensitivity (fewer false negatives) and increased specificity (fewer false positives).

Use of the graded exercise test as described is considered not to increase the hazard of testing, and perhaps even to decrease it.
Sudden, Severe Aortic Insufficiency
Authors: WIGLE E. DOUGLAS , LABROSSE CLAUDE J.
Published: June 2012

Fourteen cases of severe aortic insufficiency are presented in which an extremely elevated left ventricular pressure exceeded left atrial pressure during diastole. In 13 of the 14 cases there was proof, or strong suggestive evidence, that the aortic insufficiency was sudden in onset. In nine cases the left ventricular pressure equaled aortic pressure by end-diastole. In five cases left ventricular pressure failed to equal aortic pressure by end-diastole. The similarities between the hemodynamics of experimental and clinically occurring sudden severe aortic insufficiency, including possibly the effect of superimposed mitral insufficiency, was at times striking. The clinical picture in these cases was sufficiently distinctive that the abnormal hemodynamics could be predicted and the presence of sudden, severe aortic insufficiency suggested. The absence of the first heart sound at the cardiac apex, the presence of an early diastolic sound and "double diastolic apex beat," the harshness of the aortic systolic and diastolic murmurs, all served to make auscultatory differentiation of systole and diastole at times extremely difficult. This difficulty in differentiating the phases of the cardiac cycle by auscultation alone was in itself rather characteristic of sudden severe aortic insufficiency. The poor prognosis in these cases makes early recognition mandatory and early surgery advisable.
Anatomy of the Coronary Arteries in Health and Disease
Authors: JAMES THOMAS N.
Published: June 2012

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.
Influence of Respiration on Venous Return in Pulmonary Emphysema
Authors: NAKHJAVAN FRED K. , PALMER WILFRED H. , MCGREGOR MAURICE
Published: June 2012

The influence of respiration on the flow of blood from the abdominal vena cava into the thorax was studied in 15 patients with pulmonary emphysema and in 10 control subjects without thoracic disease or heart failure. In control subjects, during quiet breathing blood flowed into the thorax throughout the respiratory cycle at a rate which was greatest during inspiration. Simultaneously the transmural pressure of the abdominal vena cava fell and transmural right atrial pressure increased. The same pattern of flow was observed in nine of the patients with emphysema. In the other six patients, however, flow was greatly reduced or completely arrested during inspiration, with simultaneous increase in transmural caval pressure and reduction in transmural atrial pressure. This inspiratory obstruction at the thoracic inlet was associated with gross hyperinflation of the lungs and a low diaphragmatic position. It probably was not the result of the high negative and positive intrathoracic pressures that develop during inspiration and expiration, respectively, in such subjects.

It is possible that this phenomenon may account for the peripheral edema that occurs in patients who have emphysema without associated pulmonary hypertension or cardiomegaly.
Relationship of Fibrillatory Waves and P Waves in the Electrocardiogram
Authors: PETER ROBERT H. , MORRIS JAMES J. , MCINTOSH HENRY D.
Published: June 2012

The amplitude of the fibrillatory waves and the P terminal force were compared in 100 consecutive patients. These electrocardiographic measures of atrial activity were made first in atrial fibrillation and then after electrical conversion to sinus rhythm. When the same patient was studied, the occurrence of a coarse fibrillatory wave and an abnormal P terminal force, or a fine fibrillatory wave and a normal P terminal force, was found to be a highly significant relationship.

This relationship suggests that the factors responsible for the characteristic of the terminal portion of the P wave recorded in sinus rhythm probably determine the magnitude of the fibrillatory wave that occurs when atrial fibrillation is present. The finding of a coarse fibrillatory wave or an abnormal P terminal force should suggest the electrocardiographic diagnosis of left atrial hypertrophy or "strain."
Methodology of True Pulmonary Blood Volume Determination
Authors: SAMET PHILIP , BERNSTEIN WILLIAM H. , LOPEZ ALFREDO , LEVINE SYDNEY
Published: June 2012

"True" pulmonary blood volume has been determined by three indicator-dilution methods in 96 subjects. In two methods a right or left ventricular mixing chamber is interposed between the injection and sampling sites while in the third such a mixing chamber is absent. The results strongly suggest that a ventricular mixing chamber is essential for valid determination of true pulmonary blood volume.
Coronary Angiographic Findings in Correlation with Age, Body Weight, Blood Pressure, Serum Lipids, and Smoking Habits
Authors: CRAMÉR KIM , PAULIN SVEN , WERKÖ LARS
Published: June 2012

Radiological findings by coronary angiography in 224 patients, 173 males and 51 females, were graded according to the rate of filling of coronary arteries and to the presence or absence of obstruction of vessel lumen. The material was then grouped according to age, diastolic blood pressure, serum total cholesterol, serum glycerides, and smoking habits.

Age and diastolic blood pressure were not found to have any influence on frequency of coronary artery changes, presumably because of selection of patients.

In the males, elevated total serum cholesterol had only a minor influence on the frequency of coronary artery changes, while elevated glycerides were found in high frequency in patients with obstructed coronary arteries, especially in those with severe obstruction. If patients put on lipid-reducing therapy or diet were added to those with serum cholesterol higher than 280 mg/100 ml, a slight overrepresentation of coronary changes was found when compared with patients with total serum cholesterol equal to or lower than 280 mg/100 ml. The influence of elevated total serum cholesterol was in all instances inferior to that of elevated serum glycerides.

Smokers showed the frequency of coronary changes the same as or higher than patients with elevated glycerides. The influence of smoking was evident also within classes of low or elevated serum lipids.

While all conclusions must be interpreted with reference to the material selected as the source of our data, the importance of smoking as a causative agent independent of serum lipids appears conclusive.
Studies on Digitalis
Authors: SONNENBLICK EDMUND H. , WILLIAMS JOHN F. , GLICK GERALD , MASON DEAN T. , BRAUNWALD EUGENE
Published: June 2012

The effects of ouabain (0.01 mg/kg) on ventricular force-velocity relations were studied in six patients who had previously undergone corrective cardiac operations. The technique employed consisted of exposing cineradiograms at 30 frames per second and measuring the velocity of movement of roentgen-opaque markers that had been sutured to the external surfaces of the ventricles while simultaneously recording intraventricular pressures. A beat-to-beat analysis of the ventricular force-velocity relation was then accomplished by relating the velocity of marker movement and intraventricular pressure at constant ventricular dimensions. It was observed that ouabain always augmented myocardial contractility as reflected in the force-velocity relation. Velocity of shortening increased an average of 77±5 (
sem
)% while intraventricular pressure rose by an average of 23±6%. Despite this improvement in contractility, no consistent changes in cardiac output were observed. Analogous changes in force-velocity curves were obtained when a cardiac glycoside was added to isolated papillary muscles removed from normal cats. It is concluded that the fundamental action of digitalis glycosides is to augment the contractile state of the heart, whether normal or failing, but that in the absence of heart failure this improvement is not translated into an increase in cardiac output.
Diagnostic Use of Radioactive Xenon Clearance and a Standardized Walking Test in Obliterative Arterial Disease of the Legs
Authors: ALPERT J. , DEL RIOÓ H. GARCIA , LASSEN N. A.
Published: June 2012

The
133
Xe clearance method was used for studying the muscle blood flow (MBF) and the time course of the hyperemic reaction in the calf muscles during walking.

Methodological observations showed that the type of walking markedly influenced the hyperemic reaction. However, even during steady-state walking in trained subjects a variability of 15 to 20% in the muscle blood flow was noted in repeated tests.

Clinical studies were made in 11 patients with occlusive arterial disease of the femoral artery and intermittent claudication. Twelve control subjects were also studied. On use of a standardized and fairly strenuous walking test on a treadmill, all 18 legs with intermittent claudication showed abnormal
133
Xe clearance curves from the anterior tibial, the soleus, and the gastrocnemius muscles. All the curves disclosed subnormal MBF during walking and prolonged post-exercise hyperemia.

It is concluded that this
133
Xe clearance test constitutes a very direct and diagnostically valuable method for disclosing the basic pathophysiological mechanism underlying intermittent claudication.
Stethoscope Acoustics
Authors: ERTEL PAUL Y. , LAWRENCE MERLE , BROWN RICHARD K. , STERN AARON M.
Published: June 2012

This paper describes a fully calibrated and standardized acoustical test method for evaluating the transmission patterns and the filtration patterns of intact stethoscopes. An essential component of the test system is the artificial ear which duplicates the acoustical contribution of the average human ear to the stethoscope's acoustics. The transmission patterns of bell-type stethoscopes fall into four distinct groups which correspond to their basic design features. Shallow bells and single tubing design both result in attenuation at higher frequencies. A deep, trumpet-shaped bell with double tubing design may provide amplification at higher frequencies. Diaphragms attenuate the transmission acoustics of stethoscopes. When the low frequencies are selectively attenuated, high frequencies are heard more distinctly. Some diaphragms were found to attenuate at all frequencies.

The acoustical performance of any stethoscope is critical. Any attenuation of clinically significant sounds of low intensity may render them totally inaudible. The majority of stethoscopes tested (bell and diaphragm chestpieces) attenuate high frequency sounds. The adoption of stethoscopic performance criteria is urged. Few modern stethoscopes show any significant acoustical improvement since the time of Laennec.
High-Frequency Components in the Electrocardiogram
Authors: REYNOLDS ERNEST W. , MULLER BERNARD F. , ANDERSON GARY J. , MULLER BRUCE T.
Published: June 2012

Expanding the frequency response of the electrocardiogram and its derivative to 1,000 cps revealed notching in certain parts of the QRS complex which correlates with the presence of primary myocardial disease. Chi-square analysis of data from 169 patients with myocardial involvement indicated that notching on the downstroke of leads X, V
4
, and V
6
separated abnormal from normal patients at the 1% level of significance, whereas fine and coarse slurring showed reverse correlation at the 1% level of significance. This suggests that notching and not slurring is the important evidence of disease. Neither notching nor slurring was significant at the peak of the R wave in any lead. Study of individual cases revealed that complete right and left bundle-branch blocks do not mask high-frequency components caused by myocardial disease nor do they produce high-frequency components. Conclusions regarding specific diagnostic nostic criteria, however, should serve only as guidelines.
Unilateral Renal Hemodynamics and Characteristics of Dye-Dilution Curves in Patients with Essential Hypertension and Renal Disease
Authors: KIOSCHOS J. MICHAEL , KIRKENDALL WALTER M. , VALENCA MUCIO R. , FITZ ANNETTE E.
Published: June 2012

To gain information concerning cardiorenal hemodynamics in essential hypertension, renal vascular disease, and chronic glomerulonephritis, indocyanine green was used to determine renal blood flow (RBF), renal blood volume (RBV), mean transit time (MTT), appearance time (AT), buildup time (BT), and passage time (PT), in 83 kidneys of 47 hypertensive patients and eight volunteers. Cardiac output (CO) was concurrently measured. Dye, injected into the renal artery, while renal venous blood was drawn through a cuvette densitometer, gave a reproducible curve within 7.7%±2% with multi-exponential washout. RBF (dye) agreed closely (dye/PAH ratio=1.04) with para-aminohippurate (PAH) estimated renal blood flow in 18 kidneys. The RBF and RBV were significantly higher in patients with essential hypertension with high cardiac output than in those with normal cardiac output and were reduced significantly in patients with renal vascular diseases, although CO was the same. The contour of dye curves differed between the various diseases due to significant differences in BT and PT. AT and BT were significantly prolonged in patients with malignant hypertension, renal artery stenosis, and chronic glomerulonephritis. BT was significantly shorter in essential hypertensives than in normals. PT and MTT were significantly longer in malignant hypertensive, renal artery stenosis, and chronic glomerulonephritis groups. Passage time was significantly longer in glomerulonephritics than in nephrosclerotics. The procedure has value for the study of human renal circulation.
A Hemodynamic Study of Left Ventricular Aneurysm
Authors: KLEIN MICHAEL D. , HERMAN MICHAEL V. , GORLIN RICHARD , Vayo H. Westcott
Published: June 2012

Thirteen patients with left ventricular aneurysm due to coronary heart disease were studied by left heart and coronary sinus catheterization, including cineventriculography and measurement of ventricular mechanics and energetics at rest, and in some subjects, during either isoproterenol infusion or supine leg exercise. Eight patients had an aneurysm estimated to comprise greater than 20% of the left ventricular surface area, associated with increased left ventricular end-diastolic volume and pressure and mean systolic force. Average isometric rate of pressure rise and mean fiber shortening velocity and distance were uniformly decreased. Five patients had an aneurysm, estimated to comprise less than 15% of the left ventricular surface, associated with normal or nearly-normal left ventricular end-diastolic volume and pressure and mean systolic force. Average isometric rate of pressure rise was normal, but fiber shortening velocity and distance were moderately depressed. Stroke output and cardiac output were reduced in both groups.

Aneurysms exhibited either paradoxical systolic expansion or apparent lack of motion (akinesis), or both. A theoretical analysis presented indicated that when approximately 20 to 25% of left ventricular area is inactivated by any pathological process, the degree of shortening distance required of the myofiber to maintain stroke volume exceeds physiological limits, and cardiac enlargement (Starling mechanism) must ensue to maintain adequate ejection of blood. The magnitude of the salutary response of isoproterenol coupled with an increase in mechanical efficiency during catecholamine infusion suggested that myocardial catecholamines were depleted with additional aggravation of heart failure in this disease.
The Edema of Arterial Reconstruction
Authors: HUSNI E. A.
Published: June 2012

Edema of the foot and leg incident to successful arterial surgery was evaluated in 137 arterial reconstructions on the lower extremity. Both the postoperative hyperemia and the edema appeared to be directly related to the degree of pre-existent ischemia. When employed, heparin or dextran or both were effective in preventing postoperative phlebitis but did not alter the postoperative hyperemia and edema. Furthermore, phlebograms and pressure studies obtained in edematous extremities disclosed normal venous morphology and hemodynamics. The underlying mechanism for this edema is believed to be the sudden re-establishment of high pressure in an atrophic arterial tree previously exposed to a reduced intravascular pressure of long duration. This effects overstretching of the arterial bed and a remarkable increase in capillary filtration. A significant secondary factor is the compromised venous return incident to muscular atrophy and limited joint movements that are prevalent in ischemic limbs.
Effects of Induced Ventricular Fibrillation on Ventricular Performance and Cardiac Metabolism
Authors: REIS ROBERT L. , COHN LAWRENCE H. , MORROW ANDREW G.
Published: June 2012

The effects of induced ventricular fibrillation on ventricular performance and cardiac metabolism were studied in dogs. When ventricular fibrillation was induced by a brief 7.5-v a-c stimulus and allowed to persist spontaneously for one hour, no significant effects on subsequent cardiac function were apparent. An increase in myocardial oxygen consumption and a decrease in coronary vascular resistance occurred during the period of fibrillation.

When ventricular fibrillation was maintained by constant a-c stimulation, however, immediate and significantly deleterious effects on cardiac performance resulted. Coronary vascular resistance rose; myocardial oxygen consumption increased, but the increase was significantly less than in animals in which fibrillation persisted without electrical stimulation. Anerobic glycolysis ensued, leading to lactate accumulation in coronary venous blood.

The small a-c current used to maintain ventricular fibrillation impairs oxygen utilization, interferes with oxygen availability, and has a markedly deleterious effect on cardiac performance. A more satisfactory method of dependably maintaining the heart in ventricular fibrillation is needed before induced ventricular fibrillation can be safely employed to arrest cardiac contraction for prolonged periods during open cardiac operations.