bluuebunny/crossref_metadata_2025 huggingface dataset:
The Quantitative Determination of Coronary Flow with a Positron Emitter (Rubidium-84)
Authors: COHEN ALBERTO , GALLAGHER JAMES P. , LUEBS EIDE-DITTMAR , VARGA ZOLTAN , YAMANAKA JIRO , ZALESKI EDWARD J. , BLUEMCHEN GERHARD , BING RICHARD J.
Published: June 2012

An objective method for the quantitative measurement of the coronary blood flow in ml./min. using a coincidence counting system with rubidium-84, a positron emitter, is described. Accidental coincidence counts arising from independent annihilation of positrons were greatly reduced by simple shielding.

The coronary blood flow was calculated by the extrapolation of the clearance values to zero time. At this time the myocardial extraction ratio of rubidium-84 is unity and clearance is equal to flow. The accuracy of this method was demonstrated on the isolated perfused dog heart.

It was found that the rate of change of the extraction ratio of rubidium-84 in the isolated perfused dog heart and in man was not altered with changes in flow.

The finding that nitroglycerin increases the coronary blood flow in patients without coronary artery disease while decreasing it in patients with coronary artery disease was confirmed.
Kinetocardiographic Changes in Ischemic Heart Disease
Authors: EDDLEMAN E. E.
Published: June 2012

Patients with myocardial infarctions may show a paradoxic precordial outward systolic movement that can be recorded by the kineto-cardiographic technic and often is felt at the bedside.

Three types of changes occur. The first is an early systolic outward movement, which is abnormally long in duration but not sustained throughout systole. The second is a sustained outward movement during systole called a "bulge," and the third is a late systolic outward movement.

Bulges can be recorded in approximately two thirds of the patients with known infarctions with the largest outward movement most frequently noted in or near the V
3
area.

A few patients with angina may have a bulge at rest; however, apparently about 30 per cent develop a bulge on exercise.
The Cardiac Pathology of Chronic Exogenous Obesity
Authors: AMAD KAMEL H. , BRENNAN JAMES C. , ALEXANDER JAMES K.
Published: June 2012

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 findings in this study 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.
Studies on Cardiac Dimensions in Intact Unanesthetized Man
Authors: WILLIAMS JOHN F. , GLICK GERALD , BRAUNWALD EUGENE
Published: June 2012

The objective of this study was to determine the effects of nitroglycerin on ventricular dimensions. At the time of corrective cardiac operations, silver-tantalum markers were sutured to one or both ventricles of 11 patients without clinical evidence of coronary artery disease. Following recovery, cineradiograms were exposed at 30 frames per second and distances between markers were measured before and after 0.6 mg. of nitroglycerin. In all patients, end-diastolic and end-systolic dimensions decreased within 2 to 6 minutes. Right ventricular end-diastolic and end-systolic lengths decreased by an average of 5.0 per cent and 3.6 per cent of control values, respectively, while left ventricular end-diastolic and end-systolic dimensions declined by an average of 6.2 per cent and 5.9 per cent of control, respectively. The diminutions of end-diastolic ventricular dimensions approximated 30 per cent of the stroke volume. Systolic excursions decreased by an average of 13.3 per cent of control for the right ventricle, while left ventricular excursions decreased in four of the six patients. Systolic, mean, and diastolic arterial pressures decreased in each patient after nitroglycerin. Cardiac output fell from an average of 5.6 to 5.0 L./min., decreasing in each of the six patients in whom it was determined, while stroke volume fell from an average value of 65 ml./beat during the control period to 55 ml./beat after nitroglycerin.

Thus, nitroglycerin reduces both arterial pressure and ventricular dimensions and in view of the relationship between ventricular size, myocardial tension, and oxygen consumption, this action tends to reduce cardiac oxygen requirements and may explain, at least in part, the effectiveness of the drug in angina pectoris.
Beta-Adrenergic Blockade in the Treatment of Exercise-Induced Paroxysmal Ventricular Tachycardia
Authors: TAYLOR ROGER R. , HALLIDAY EDWARD J.
Published: June 2012

The β-adrenergic blocking drug pronethalol was effective in the treatment of a patient with exercise-induced paroxysmal ventricular tachycardia. Adrenergic stimuli are considered important in initiating this arrhythmia. The mode of action of pronethalol is briefly discussed in relation to other antiarrhythmic agents.
Isoenzymes in Clinical Diagnosis
Authors: GOODFRIEND THEODORE L. , KAPLAN NATHAN O.
Published: June 2012

The recent literature attests to the increasing number of enzymes for which isoenzymes or subunit structure or both are known. Several symposia and reviews have been published within the past few years.
46-50
Some enzyme activities for which isoenzymes have been described are listed in table 4. Only those found in mammals are included. They are ranked in rough order of apparent usefulness in clinical diagnosis, with the enzymes displaying tissue localization and catalytic differences listed first. Also, the number of molecular forms and the presence or absence of known subunit structure is indicated.

Clinical studies have been made using several of the isoenzymes listed in table 4, and references denoting these studies are marked with an asterisk. Data presented in the table indicate that valuable clinical information might derive from study of other isoenzymes, notably phosphofructokinase, for which tissue differences and adaptable catalytic differences exist. The guidelines set forth in this review can be used for investigating still other isoenzymes, such as those studied in lower forms.
79-85
In brief, the study of isoenzymes, like the study of enzymes and other organ-specific chemicals, presents an opportunity for great specificity and accuracy in localizing and following disease processes.
Palliative Surgery in Tricuspid Atresia
Authors: SUBRAMANIAN S. , CARR IAN , WATERSTON D. J. , BONHAM-CARTER R. E.
Published: June 2012

Forty-two children diagnosed as having tricuspid atresia with diminished pulmonary blood flow are discussed. Palliative shunt surgery was done in each of these children. None of the eight infants who weighed less than 10 lb. at the time of operation survived. In 17 operations on infants who weighed between 10 and 15 lb. there were four operative and four late deaths. Glenn's operation is practicable and has been found relatively satisfactory in this group. In 21 operations on children who weighed above 15 lb. there were no operative deaths and one late death. The 17 children aged over 1 year at the time of operation are alive. In one child heart failure followed a Potts anastomosis, but regressed after Glenn's operation.
Idiopathic Enlargement of the Right Atrium
Authors: SUMNER ROBERT G. , PHILLIPS JOHN H. , JACOBY WILLIAM J. , TUCKER DONALD H.
Published: June 2012

Four patients with idiopathic enlargement of the right atrium are described. All patients were evaluated carefully by clinical means and two were subjected to extensive investigation including cardiac catheterization, angiocardiography, and intracavitary electrocardiography.

The diagnosis of idiopathic enlargement of the right atrium is based primarily on radiographic examination with exclusion of other causes of right atrial enlargement by appropriate clinical and laboratory means. In the patients studied no cause for the right atrial abnormality could be established. Nonetheless, it is concluded that this disease is a distinct clinical entity that deserves further recognition and investigation.
Digital Casts for the Study of Clubbing of the Fingers
Authors: MELLINS ROBERT B. , FISHMAN ALFRED P.
Published: June 2012

A method is described for the production of accurate casts of the digits using an alginate impression material. The use of such casts is illustrated with respect to changes in the degree of digital clubbing in tetrad of Fallot following total surgical correction.
Abnormalities of Renal Function and Circulatory Reflexes in Primary Aldosteronism
Authors: BIGLIERI EDWARD G. , MCILROY MALCOLM B.
Published: June 2012

The renal response to intravenous administration of isotonic saline solution and circulatory reflex reactivity was studied in nine patients with primary aldosteronism before and after surgical removal of an adrenal adenoma. In preoperative tests, infusion of saline was followed by abnormally rapid renal excretion of sodium and water, such as occurs in patients with autonomic insufficiency. Circulatory reflex function was also abnormal in all patients; the most severe impairment was shown by two patients with hypokalemia and weakness of long duration. Postoperatively, both renal and circulatory reflex responses returned to normal or near normal. In preoperative tests on three patients, potassium repletion effected a similar correction of both renal and circulatory reflex abnormalities. The cause of these abnormalities in patients with primary aldosteronism is not known. Potassium depletion may be a factor, although a general disturbance of autonomic cardiovascular function cannot be excluded.
Adaptation to Exercise in Angina Pectoris
Authors: MACALPIN REX N. , KATTUS ALBERT A.
Published: June 2012

Twelve patients with angina pectoris manifested an ability to adapt to exercise during treadmill stress testing with electrocardiographic monitoring. Three patterns of adaptation were seen. Nine subjects had the ability to continue walking after the onset of angina with eventual disappearance or lessening of anginal pain and the associated ischemic ST-segment depression; anginal pain and ST depression began to diminish during a steady state of blood pressure and heart rate in those cases in which these factors were measured. Four subjects were able to continue walking for long periods of time during a state of angina and ischemic ST depression. Three subjects demonstrated an increase in exercise capacity after being warmed up by a preceding bout of exercise-induced angina; blood pressures and heart rates during the initial, "warming-up" effort tended to be higher than those during the early stages of the second effort. In three subjects more than one of these patterns of adaptation were demonstrated. Five of the subjects showed striking subjective and objective improvement in exercise tolerance while on a program of regular walking exercise.

Selective coronary cineangiography was performed in eight of these patients and two patterns of coronary disease were seen: (1) occlusion of a major coronary vessel with good collateral channels circumventing the obstruction; (2) strategically placed, proximal, stenotic lesions in major coronary vessels without frank occlusion and without discernible collateral development.

Some diagnostic and therapeutic implications of these findings are discussed.
Transposition of the Great Vessels
Authors: FERENCZ CHARLOTTE
Published: June 2012

A microscopic study of the lungs of 106 patients with transposition of the great vessels has revealed early and severe hypertensive alterations in the pulmonary arteries. These striking changes, associated in almost all instances with normal pulmonary veins, indicate a state of high resistance of the arterial bed.

Pulmonary arterial damage was, in general, most advanced in the patients with a large ventricular septal defect, but in spite of this these were the patients who lived longest. It seemed obvious, therefore, that their relatively favorable course was due to a greater beneficial than damaging effect of the ventricular septal defect.

Consideration of these findings in the light of known physiologic data has led to a clarification of the physiologic variations of the transposition circulation. Using the recognized physiologic definitions of flows and shunts the transposition circulation is characterized by a diminished effective flow and a bidirectional but predominantly left-to-right shunt. The effect of a large intracardiac communication is to increase the effective flow and to lessen the shunts. With increasing size of the intracardiac communication the spectrum is completed when the circulatory characteristics of a single ventricle are reached in which the anatomic position of the great vessels becomes physiologically insignificant.

The effect of a common systolic ejectile force in patients with a large ventricular septal defect will be similar in the transposition circulation and in the normal circulation. Three physiologic states are possible which depend upon the relative magnitude of the systemic and pulmonary resistances.

The early appearance and malignant nature of the hypertensive alterations in the pulmonary arteries of patients with transposition of the great vessels suggest that the impact upon the lungs of high blood flow and pressure is aggravated by arterial vasoconstriction. This may be initiated by anoxia and a lowered blood pH. Elevation of pulmonary venous pressure and the increased viscosity of the blood due to polycythemia may add to the damage.

Prominence of the bronchial arteries noted in the lung sections suggests that an expanded bronchial circulation augments the effective flow in these patients. If the bronchial venous drainage leads to systemic veins, the bronchial circulation could act as an accessory pulmonary circulation and could improve the effective flow without having to cross the already overloaded intracardiac communications.

The anatomic findings and physiologic considerations reported in this study reveal several aspects of the early and severely damaging cardiopulmonary effect of transposition of the great vessels and indicate an urgent necessity of surgical therapy in early life.
Pulmonary Pressure, Cardiac Output, and Arterial Oxygen Saturation during Exercise at High Altitude and at Sea Level
Authors: BANCHERO NATALIO , SIME FRANCISCO , PEÑALOZA DANTE , CRUZ JULIO , GAMBOA RAÚL , MARTICORENA EMILIO
Published: June 2012

The response elicited by exercise on pulmonary pressure, cardiac output, and arterial oxygen saturation in 35 lifetime residents of high altitude has been studied at high altitude (14,900 feet above sea level), and 22 residents of low altitude have been studied at sea level. A procedure combining cardiac catheterization, arterial cannulation, and spirometry was carried out. The exercise was moderate and was performed in supine position using a bicycle ergometer, the work load being 300 kg-m/min/m,
2
and the average increase of the oxygen uptake being 4.7 times at sea level and 4.8 times at high altitude.

Both at sea level and at high altitude the cardiac output augmented during exercise proportionally to the increase in oxygen uptake, and thus followed the pattern of response described by other authors. The cardiac output as well as the oxygen intake, for the magnitude of exertion performed in this study, was almost the same at sea level and at high altitude. The cardiac output rose during exercise almost exclusively as a result of an increase in the heart rate, with the stroke volume remaining practically constant.

Despite similar increase in cardiac output, the response of pulmonary pressure was smaller for sea-level subjects than for the high-altitude subjects. Increments of mean pulmonary pressure of nearly 50% and 100% were observed on exercise at sea level and at high altitude, respectively.

During exercise the arterial oxygen saturation did not change in the sea-level studies, but decreased significantly in the high-altitude studies. The decrement observed in high-altitude residents is related to a fall in arterial pO
2
which at resting conditions is placed on the steep part of the oxygen dissociation curve.
Recurrent "Pericardial Pain" after Pericardiectomy for Recurrent Acute Benign Pericarditis
Authors: GOLDFARB BEN , GOLD DAVID , LATTS ELLIOT , WEXLER HAROLD , WANG YANG
Published: June 2012

Two cases of recurrent acute benign pericarditis are presented. Both were characterized by recurrent "pericardial type" pain after nearly total pericardiectomy, a previously unreported occurrence. A plausible explanation for this paradox is presented.
Some Effects of Nitroglycerin upon the Splanchnic, Pulmonary, and Systemic Circulations
Authors: FERRER M. IRENÉ , BRADLEY STANLEY E. , WHEELER HENRY O. , ENSON YALE , PREISIG RUDOLPH , BRICKNER PHILIP W. , CONROY RICHARD J. , HARVEY RÉJANE M.
Published: June 2012

Splanchnic, pulmonary, and systemic hemodynamics were studied in 18 patients after the sublingual administration of nitroglycerin. The drug, contrary to expectations, produced an over-all vasoconstrictive effect on the splanchnic circulation rather than vasodilatation. There was no evidence of venous pooling in this bed, and indeed the data may indicate a splanchnic supportive role in augmenting venous return to the heart with disengorgement of its own volume. In contrast, there was vasodilatation and pooling of blood in the pulmonary vascular bed. The systemic circulation probably sustains several effects by nitroglycerin, including arterial vasodilatation. A direct change in large artery distensibility probably explains the modest fall in systolic blood pressure seen. Further decline in arterial pressure may depend on venous pooling of a small or large degree. Probably the fall in systemic and specific organ flows is also linked to decreased venous return and the vascular readjustments provoked thereby. Pulsus alternans was produced by nitroglycerin, a previously unreported effect of the drug, but the mechanism by which it arose could not be defined.
Renal Hemosiderosis in Patients with Prosthetic Aortic Valves
Authors: ROBERTS WILLIAM C. , MORROW ANDREW G.
Published: June 2012

Seven patients with prosthetic aortic valves and anemia are described. In six, the Teflon valves had become incompetent as a result of perforations or tears in the prosthetic cusps, and in the seventh the valve was severely stenotic as well as regurgitant. The anemia in each patient was secondary to intravascular hemolysis resulting from damage to the erythrocytes traversing the malfunctioning valve. Severe renal hemosiderosis, the anatomic indicator of severe intravascular hemolysis, was present in each patient. Although deposits of iron in the kidney in these circumstances may be extreme, no significant renal damage nor impairment of renal function appears to occur as a result of this deposition.
Analysis of Experience in Workmen's Compensation for Heart Cases
Authors: BERGY GORDON G. , SPARKMAN DONAL R.
Published: June 2012

In this study of industrial insurance experience in cardiac cases in the State of Washington, particular attention was given to the consistency of medical opinion regarding causal relation of effort to heart attack and to the role of physicians in arriving at decisions as to such causal relationship. Four hundred thirty-one cardiac claims (53% of the total claims) submitted to the Washington State Department of Labor and Industries between 1950 and 1958 were reviewed. Twenty-one and three-tenths per cent of the claimants had documented prior heart disease. Only 6.6% had previous accepted claims for heart disease. At least 78% of all claimants whose records were studied had coronary heart disease and of the deaths, 97.8% were due to manifestations of atherosclerosis. Cardiac trauma was a rarity, occurring in 0.6% of the total and was nonfatal in all cases.

In the opinion of the authors causal relationship to the work being performed was present in 71% of the "death" cases in which compensation was allowed; conversely, it was demonstrable in only 31% of the cases of living claimants in which compensation was granted.

After the introduction of criteria for causal relationship by the Washington State Heart Association and internist panels, the following changes occurred: (1) The consistency of the assessment of causal relationship to accepted medical opinion improved, for (a) rejection of claims, where causal relationship to work existed, were fewer, and (b) the acceptance of claims where causal relationship was lacking, decreased. (2) The incidence of appeals decreased. Thus, criteria for guidance of physicians in the determination of causal relationship appear to be valuable, and determination of causal relationship and rating of disability may be better performed by a person other than the patient's attending physician.
Left Ventricular Function Following Replacement of the Aortic Valve
Authors: ROSS JOHN , MORROW ANDREW G. , MASON DEAN T. , BRAUNWALD EUGENE
Published: June 2012

Evaluations of left ventricular myocardial function were carried out in 14 patients 4 to 16 months after stenotic or regurgitant malformations of the aortic valve had been corrected by valve replacement. The circulatory responses to exercise, judged by the increases in cardiac output in relation to the increases in oxygen consumption, were normal or only mildly reduced in 12 patients. In five patients, the relationships between the change in the left ventricular end-diastolic pressure and the alteration in the stroke volume were also normal, a fall or an increase in left ventricular end-diastolic pressure of less than 3 mm. Hg being accompanied by an increase in stroke volume. In eight patients, however, abnormal increases in the left ventricular end-diastolic pressure occurred during exercise, and in four the left ventricular end-diastolic pressure was increased to levels above 12 mm. Hg. Variable alterations in the stroke volume accompanied these increases in end-diastolic pressure. It is suggested that in the three patients who exhibited simultaneous increases in left ventricular end-diastolic pressure and stroke volume, the changes were either a manifestation of the Frank-Starling mechanism, or primarily the result of a positive inotropic influence. In the five patients who exhibited increases in left ventricular end-diastolic pressure, but no change or a fall in stroke volume, it is proposed that a distinct depression of left ventricular performance was present. Thus, while the cardiac output response was adequate to meet the stress of exercise in the majority of the patients studied following aortic valve replacement, determination of the relationship between the left ventricular end-diastolic pressure and the stroke volume permitted the detection of abnormalities in the function of the left ventricle.
Blood Cell Aggregation and Screen Filtration Pressure
Authors: SWANK ROY L. , DAVIS ELI
Published: June 2012

Changes in the microcirculation of the conjunctiva were compared with the screen filtration pressure (SFP) of venous blood in presumed normal subjects and in others with known systemic disease. The presence of arteriolar aggregation and of other circulatory abnormalities was not attended by significantly different mean SFP values. When, however, 2.5 µg of adenosine diphosphate (ADP) per milliliter were added to blood in vitro 20 to 30 seconds before the SFP determination, the SFP increased. In subjects with normal microcirculation, the increase was slight; in those with abnormal circulation, it was marked. When abnormal changes in the circulation were present, or ADP potentiation was high, there was an increase in the spread of control SFP values. Also when the ADP potentiation was high, the control SFP values were slightly higher than when the SFP potentiation was low. Two serotonin antagonists did not prevent or decrease the increase in SFP by ADP.
Tricuspid Leaflet Aortic Valve Prosthesis
Authors: ROE BENSON B. , KELLY PAUL B. , MYERS JOHN L. , MOORE DAVID W.
Published: June 2012

The theoretical and practical advantages of the flexible-leaflet prosthetic aortic valve make it worthy of continued development. Laboratory and clinical experience with a precision-molded, single-unit, tricuspid silicone rubber prosthesis suggest that the problems of materials, construction, and performance have been overcome. The use of a suitable elastomer in a precision casting with an anticlotting surface coating has resulted in a leaflet prosthesis the long-term functional performance of which should compare favorably with any device currently in use.
Complete Heart Block Following Replacement of the Aortic Valve
Authors: GANNON PAUL G. , SELLERS ROBERT D. , KANJUH VLADIMIR I. , EDWARDS JESSE E. , LILLEHEI C. WALTON
Published: June 2012

The incidence of postoperative complete heart block in a series of 124 cases of replacement of the aortic valve by a ball valve prosthesis was 12.9% (16 of 124). In all but one case, complete heart block was treated by pacing the heart with an artificial pacemaker.

The complete heart block was temporary in seven cases and persistent in nine. Six of the patients with acute persistent complete heart block died within ten days of operation, and one patient died on the forty-ninth postoperative day. Two patients are alive, both with implanted pacemakers. Five of the seven patients who resumed their preoperative rhythm survived.

Among the 16 patients with some form of complete heart block postoperatively, nine died (56.2%).

The basis for surgical induction of complete heart block when placing a ball valve prosthesis in the aortic orifice lies in the proximity of the bundle of His and its left branch to the aortic valve. In particular, the inferior aspect of the noncoronary cusp is closely related to major conduction tissue. Under the conditions of this operation, the conduction tissue may be strangulated or injured by sutures, or it may be injured when calcific material of the diseased aortic valve is removed.

It is of interest that the incidence of postoperative complete heart block in this series was approximately the same with the Starr-Edwards sutured prosthesis (that is, 13%; 11 of 84 cases) as it was with the Magovern sutureless prosthesis (12.5%; 5 of 40 cases).
An Objective Test to Demonstrate the Circulatory Abnormality in Intermittent Claudication
Authors: COFFMAN JAY D. , MANNICK JOHN A.
Published: June 2012

The exercise test as described in this study gives graphic evidence of the deficit in muscle blood flow during exercise in patients with intermittent claudication. It is easy to perform and can be done on an outpatient basis. The equipment cost is reasonable, NaI
131
is available in most hospitals, and the amount of radioactive material received by the patient is very small. Two people can perform the test on both legs of a patient in 45 minutes. Records are easy to interpret; if the isotope disappearance stops, the counts need not even be plotted to determine if the test is abnormal.

The exercise test can be used in the diagnosis of leg pain of uncertain etiology, to study the effects of medical or surgical treatment, and in the clinical investigation of the symptoms of intermittent claudication.
Hemodynamics of Complete Transposition of the Great Vessels Before and After the Creation of an Atrial Septal Defect
Authors: SHAHER REDA M. , KIDD LANGFORD
Published: June 2012

Pressures, hemoglobin, and oxygen saturations were measured and shunts and flows calculated before and after the surgical creation of an atrial septal defect in 20 patients with complete transposition of the great vessels. Eleven patients had intact ventricular septa and nine had ventricular septal defects. Of the group with intact septa, the shunt increased in nine and diminished in one; arterial oxygen saturation increased in nine and diminished in one; hemoglobin content decreased in eight and increased in two; systemic blood flow increased in six, diminished in two, and was unchanged in one; and pulmonary blood flow diminished in two. Of those with a ventricular septal defect, the shunt increased in all but one; arterial oxygen saturation increased in four, remained the same in two, and diminished in three; hemoglobin content increased in five and diminished in four; systemic blood flows increased in five and diminished in three; and pulmonary blood flows diminished in four.

It was concluded that the procedure does not improve arterial oxygen saturation in any patient in whom the arterial oxygen saturation is 65% or more initially, and that this operation is primarily of benefit when there is an intact ventricular septum.
Respiratory Mechanics Following Open-Heart Surgery for Acquired Valvular Disease
Authors: GARZON ANTONIO A. , SELTZER BERNARD , KARLSON KARL E.
Published: June 2012

1. Pulmonary mechanics were determined preoperatively and postoperatively in 20 patients following open-heart surgery for acquired valvular disease.

2. The surviving patients had minimal increase of the work of breathing, associated with an increase in nonelastic resistance during the early postoperative period. These changes in pulmonary mechanics are insufficient to explain the respiratory difficulties experienced by these patients.

3. In the fatal cases compliance decreased to half the preoperative level, and respiratory work increased to five times the preoperative value. In these individuals excessive work of breathing produces a significant demand on physiological resources, and controlled mechanical ventilation is indicated.
Off-Line Monitoring in Ischemic Heart Disease
Authors: MAZZARELLA JOHN A. , BRUCE ROBERT A. , GREEN ELMER
Published: June 2012

The general clinical concept of cardiac monitoring has been briefly defined. The need for its use in acute myocardial infarction has been cited, and a new approach to "off-line" electrocardiographic recording on magnetic tape with very rapid scanning and analysis has been described. Some observations related to clinical problems in myocardial infarction, arrhythmias, conduction defects, and cardiac pacing, have been illustrated. The benefits and limitations have been cited. "Off-line" systems complement but do not supplant current on-line alarm systems. This technique appears to be clinically useful both for inpatients and for ambulatory outpatients. The major indications for cardiac monitoring are arrhythmias, heart block, cardiac responses to a variety of stresses, diseases, and therapy, as well as some patients with unexplained symptoms.
Focal Lipid Lesions in Blood Vessels due to Erythrocytes and Platelets
Authors: BARNARD P. J. , THOMPSON D. H.
Published: June 2012

Experiments on goats and rabbits living on a normal diet demonstrated that the lipid associated with organizing thrombi became concentrated in fibrosed focal lesions of blood vessels. The lipid that appeared during organization of lysed erythrocytes underwent changes similar to those of lipid in thrombi. From this it was concluded that what red cells there were in the thrombi contributed to the total lipid present.

These observations are pertinent to the pathogenesis of atherosclerosis, because they help to explain the thrombosis characteristically associated with this disease, and how lipid can be delivered to restricted regions of the arterial intima.
Correlation of the Pressor Activity of the Renal Venous Effluent with Excretory Function and Other Tests in Focal, Parenchymal, and Vascular Renal Disease
Authors: MCPHAUL JOHN J. , MCINTOSH DUNCAN A. , WILLIAMS LESTER F. , GRITTI EMIL J. , GROLLMAN ARTHUR
Published: June 2012

A series of 170 hypertensive patients suspected of suffering from renovascular disease have been subjected to various tests designed to identify the presence of a surgically remediable lesion.

The presence of a pressor agent in the renal venous effluent, as determined by bioassay on the rat, has proven to be an accurate method for detecting the presence of renovascular hypertension responsive to surgical treatment. Split-function excretory tests, aortography, and other tests used for this purpose could not be relied on as the sole criterion as to whether surgical intervention is indicated in a given patient.
Congenital Absence of the Left Pericardium
Authors: NASSER WILLIAM , FEIGENBAUM HARVEY , HELMEN CHARLES
Published: June 2012

A case of complete absence of the left pericardium, suspected from plain chest x-rays and proved by diagnostic left pneumothorax, has been reported. The significance of the pericardium in relation to cardiac function is discussed. Because absence of the left pericardium is a benign and relatively asymptomatic anomaly that usually requires no treatment, it behooves the clinician and radiologist to become cognizant of its presence.
Incidence of Bacterial Endocarditis in Ventricular Septal Defects
Authors: SHAH PRAVIN , SINGH WALTER S. A. , ROSE VERA , KEITH JOHN D.
Published: June 2012

In summary, the population figures presented place the risk of bacterial endocarditis for cases of ventricular septal defect in the 5 to 14-year age group as 1 in 470 patient years, or 2.1 per 100 cases in 10 years. The estimated risks for the 5-year-old and 15-year-old patient up to the age of 70 years would be 13.6% and 11.5% respectively. In the city of Toronto, only four cases were seen in 10 years in the general population of over half a million, while in metropolitan Toronto with the population of 1.3 million, eight cases were seen in a similar period. If the clinical experiences of the various authors reported in the literature are pooled with that at The Hospital for Sick Children in Toronto, one would have 21 cases of bacterial endocarditis in 11,328 patient years. This would place the incidence as approximately 1 in 500 patient years.

It is suggested that the surgery for ventricular septal defect may itself initiate bacterial endocarditis as noted in three of our cases.

On the basis of the available data, there is insufficient evidence to designate the risk of future bacterial endocarditis as an adequate reason for surgical closure of the defect.
The Electrocardiogram in Tricuspid Atresia and Pulmonary Atresia with Intact Ventricular Septum
Authors: GAMBOA RAUL , GERSONY WELTON M. , NADAS ALEXANDER S.
Published: June 2012

Electrocardiograms were studied in 37 patients with tricuspid atresia and in 20 with pulmonary atresia and intact ventricular septum. The results were correlated with angiocardiographic findings and postmortem examinations. Differential features were as follows:

1. Biatrial hypertrophy with characteristic P "tricuspidale" was noted in 81% of the electrocardiograms in patients with tricuspid atresia, whereas this pattern was seen in only two infants with pulmonary atresia and intact ventricular septum.

2. In tricuspid atresia, left axis deviation was usually directed posteriorly; however, anmal or right axis deviation was present in seven cases, six of whom were type 2C and the seventh, type 1A. In every case the horizontal QRS axis was oriented posteriorly. By contrast, in patients with pulmonary atresia there were no instances of left axis deviation in the frontal plane. Normal frontal plane axis was present in 12 patients, all of whom were type I; right axis deviation was evident in eight patients including the three infants with type II deformity. The horizontal QRS axis was usually directed posteriorly; however, anterior orientation occurred in several patients.

3. A typical feature of the vectorcardiogram in patients with tricuspid atresia was the increased anterior magnitude of the initial forces followed by a sharp posterior shift. The initial forces in patients with pulmonary atresia were not characteristic.

4. The electrocardiographic features in patients with tricuspid atresia and normal position of the great vessels showed decreased right ventricular potentials consistent with true hypoplasia of the right ventricle, but in patients with pulmonary atresia similar lack of right ventricular potentials could be correlated with decreased right ventricular cavity, whereas the ventricular wall was actually hypertrophied.
Ventricular Pressure-Flow Dynamics in Tetralogy of Fallot
Authors: LEVIN AARON R. , BOINEAU JOHN P. , SPACH MADISON S. , CANENT RAMON V. , CAPP M. PAUL , ANDERSON PAGE A. W.
Published: June 2012

The present study was conducted to determine the instantaneous pressure-flow relationships across the ventricular septal defect in tetralogy of Fallot. Simultaneous right and left ventricular pressures and the pressure gradient were recorded with matched catheter systems. Biplane cineangiocardiography was used to evaluate the timing of the bi-directional shunts during various phases of the cardiac cycle. The instantaneous pressure differences between the two ventricles and the direction of the pressure gradient correlated well with the timing of the shunt across the defect.

In 27 patients with moderate tetralogy of Fallot, a consistent pattern of bidirectional shunting was shown. The right-to-left shunt occurred at two places and two sites during the cardiac cycle; namely, during early ventricular ejection into the aorta, and during isovolumic ventricular relaxation directly across the ventricular defect into the left ventricle. Left-to-right gradients and shunting across the defect were found to occur during isovolumic ventricular contraction and during diastole. The results of this study suggest that further investigation of various cardiac defects may yield important information concerning shunting mechanisms.
Anomalous Pulmonary Venous Drainage
Authors: MOHIUDDIN SYED M. , LEVIN HUGH S. , RUNCO VINCENT , BOOTH RICHARD W.
Published: June 2012

An anomaly of pulmonary venous drainage in an 8-year-old child is described whereby all four pulmonary veins emptied into a common chamber which in turn communicated with both the left atrium and the inferior vena cava. The venous anomaly and an accompanying atrial septal defect were demonstrated by selective cineangiocardiography. Ligation of the vein at the level of the right diaphragm, thus rerouting the entire pulmonary venous return through the alternate pathway to the left atrium, was tolerated without difficulty. The embryology, diagnosis, and surgical management of the anomaly are discussed.
Alterations in Regional Pulmonary Blood Flow in Mitral Valve Disease Studied by Radioisotope Scanning
Authors: FRIEDMAN WILLIAM F. , BRAUNWALD EUGENE
Published: June 2012

The distribution of pulmonary blood flow was studied by external scintillation scanning of intravenously injected
131
I-labeled macroaggregates of human serum albumin. The technique, its validation, and the underlying considerations are discussed in detail.

In 13 normal subjects, in whom the indicator was injected while they were in the erect position, the ratio of concentration of radioactivity per unit of lung volume in the upper third of the right lung to that in the lower third (U/L) averaged 0.43±0.08
sd
. When
131
I-MAA was injected with the subjects in the supine position, this ratio averaged 0.92±0.05.

In 35 patients with mitral valve disease in whom the injections were made while they were in the erect position, varying abnormalities of the distribution of the pulmonary arterial blood flow were observed, U/L averaging 1.01±0.34. The extent of the abnormality of distribution was found to be a function of the hemodynamic severity of the mitral valve disease, and U/L correlated more closely with the mean left atrial pressure than with any other hemodynamic variable. The potential applicability of the
131
I-MAA technique in the detection and assessment of mitral valve disease was discussed.
Considerations Regarding the Technique for Transseptal Left Heart Catheterization
Authors: ROSS JOHN
Published: June 2012

Improvements in the equipment and technique for transseptal left heart catheterization appear to have largely overcome the major problems and complications that have been encountered in recent years with this procedure. Improvements in equipment have included the addition of a stylet for the needle, modifications in the design of the catheter, and the use of a catheter tip occluder both for manipulation of the catheter within the left heart and to close the end hole during selective angiography. The steps employed for insertion of the catheter and needle were described in detail, and the use of landmarks such as the left main-stem bronchus, the spine, the left atrial shadow, and the aortic bulge was discussed. The indications for, and relative contraindications to, transseptal catheterization currently applied in this laboratory were also described. The relative contraindications consist of (1) a giant right atrium, (2) severe rotational anomalies of the heart or great vessels, and kyphoscoliosis; (3) marked dilation of the ascending aorta; (4) anticoagulant therapy, and (5) a history of recent systemic arterial embolization. Since the introduction of these technical changes and precautions, with the exception of one nonfatal aortic puncture, the problems previously encountered during transseptal catheterizations have been avoided in more than 350 consecutive transseptal left heart studies in this laboratory.
Kinetocardiogram, Phonocardiogram, and Arterial Pulse Waves During Acute Hemodynamic Changes
Authors: DADDARIO ROBERT C. , FREIS EDWARD D.
Published: June 2012

The effects of drugs that produce known hemodynamic alterations were assessed on externally recorded pulse waves, heart sounds, and the relationship of these to each other and to the electrocardiogram.

The shape of the carotid pulse and the carotid-femoral pulse-wave transmission time difference showed changes that could be related to alterations in central arterial distensibility. The ratio of the second to the first positive inflection, and of the incisura to the first positive inflection of the carotid pulse wave, increased following use of drugs which raised mean arterial pressure and decreased after those which lowered blood pressure. The carotid-femoral transmission time difference decreased with vasopressor agents, increased with amyl nitrite and hexamethonium, and showed no consistent change after isoproterenol.

Left ventricular ejection time, measured from the carotid pulse, changed in relation to heart rate, increasing with cardiac slowing and decreasing when the rate accelerated. The ejection time index remained unchanged except for a slight increase following amyl nitrite and a decrease after hexamethonium.

Alterations in isovolumic contraction time approximately paralleled changes in diastolic pressure. The ratio of diastolic pressure to isovolumic contraction time provides an index of the rate of rise of left ventricular pressure. The quotient of diastolic pressure divided by isovolumic contraction time increased with adrenergic stimulation (isoproterenol) and decreased after ganglion blockade. It was not significantly changed by angiotensin II, methoxamine, or amyl nitrite.

The interval between the onset of QRS and the beginning of the first heart sound (Q-S
1
), shortened considerably after isoproterenol and moderately following amyl nitrite. It increased after hexamethonium and remained essentially unchanged following angiotensin II or methoxamine. These results suggest that the Q-S
1
interval may reflect ventricular contractility in the absence of mitral valvular disease.

The amplitude of the first heart sound appeared to be a sensitive indicator of ventricular contractility increasing with isoproterenol and amyl nitrite, decreasing with hexamethonium and remaining unchanged following use of angiotensin II or methoxamine.
Cardiac Catheterization Studies after Combined Tricuspid, Mitral, and Aortic Valve Replacement
Authors: BRISTOW J. DAVID , KLOSTER FRANK E. , HERR RODNEY , STARR ALBERT , MCCORD COLIN W. , GRISWOLD HERBERT E.
Published: June 2012

Postoperative cardiac catheterizations were performed in eight patients within the first year following replacement of the tricuspid, mitral, and aortic valves with Starr-Edwards ball-valve prostheses. Two additional patients were studied who had mitral and tricuspid replacement. Before surgery the patients characteristically had distinct elevation of right and left atrial pressures, and markedly reduced cardiac outputs. Four individuals had marked pulmonary hypertension. At the postoperative catheterizations, consistent changes were an increase in cardiac output, a decrease in right and left atrial pressures, and a decrease in right ventricular systolic pressure. The last change was particularly notable in those individuals who had marked pulmonary hypertension before surgery.
Hemodynamic State Early after Prosthetic Replacement of Mitral Valve
Authors: RASTELLI G. C. , KIRKLIN JOHN W.
Published: June 2012

Cardiac output, stroke volume, and atrial, pulmonary arterial, left ventricular, and systemic arterial pressures were measured preoperatively, during operation, and for 48 hours thereafter in 14 patients undergoing prosthetic replacement of the mitral valve. Cardiac output was usually abnormally low after repair, being lowest 3 to 6 hours after operation. This pattern was different from that in a patient undergoing plication of the posterior leaflet and very different from that in a patient undergoing removal of a left atrial myxoma, who served as controls.

Ventricular filling pressure was high, there was no significant diastolic pressure difference across the Starr-Edwards prosthesis, and there was no pressure difference across the left ventricular outflow tract. Blood gas levels and pH were within satisfactory range.

The data are interpreted as indicating that impairment of ventricular performance, particularly left, usually contributes significantly to the low cardiac output in these patients. This is probably related in part to preoperative ventricular function. Possible additional contributing factors are discussed.
Current Experience in the Diagnosis of Pheochromocytoma
Authors: SHEPS SHELDON G. , TYCE GERTRUDE M. , FLOCK EUNICE V. , MAHER FRANK T.
Published: June 2012

The pharmacological and biochemical tests available for the diagnosis of pheochromocytoma were evaluated among 28 patients with proved tumors and 148 other patients in whom the diagnosis was suspected. Of the biochemical tests on urine, determinations of total metanephrines (MN) and of vanilmandelic acid (VMA) were much less subject to false-positive results than was determination of catecholamines (CA). Since urinary MN values changed the most in tumor patients, MN determination is preferred as the current screening test. Of the pharmacological tests, the histamine test continues to be the most valuable, especially when combined with determination of plasma CA concentration. The phentolamine (Regitine) test has not proved to be of any distinct value as a primary diagnostic aid. Any of the chemical or pharmacological tests occasionally may give a false-positive result. The urinary output of excessive amounts of homovanillic acid (HVA) was an indication of the presence of pheochromocytoma with some features histologically similar to other neural crest tumors but was not an indication of malignancy. Reliable diagnosis of pheochromocytoma still must be based on multiple studies in an appropriate clinical setting.