bluuebunny/crossref_metadata_2025 huggingface dataset:
Ultrastructure of the Human Carotid Body
Authors: GRIMLEY PHILIP M. , GLENNER GEORGE G.
Published: June 2012

Surgically excised human carotid bodies have been analyzed by electron microscopy. Several ultrastructural features suggest that they are closely related to sympathetic neuroendocrine glands and autonomic ganglia: the chief cells synthesize intensely osmiophilic cytoplasmic granules, occasionally develop neuroid processes, and are intimately associated with neurilemmal sustentacular cells. Other lines of evidence indicate that secretion of the chief cell is norepinephrine or a closely related bioamine-neurotransmitter. The role of chief cells in mediating chemosensation may be explained by modulated release of the bioamine in response to local metabolic conditions. Human chief cells are richly innervated. Recognizable zones of synapse display an efferent type of polarity and sometimes appear adrenergic. Thus, reflexive sympathetic excitation of chief cells may be physiologically significant in man. The anatomic compartmentalization characteristic of carotid body chief cells is discussed in relation to a possible functional significance.
Hemodynamic Studies One Year After Homograft Aortic Valve Replacement
Authors: KENNEDY J. WARD , TWISS R. D. , BLACKMON J. R. , MERENDINO K. ALVIN
Published: June 2012

Clinical and hemodynamic evaluation has been carried out one year after homograft aortic valve replacement in 15 patients. These studies have included an evaluation of pressure gradients across the aortic valve, supravalvular cineangiocardiography, and left atrial biplane angiocardiography for the measurement of left ventricular volume, left ventricular mass, and quantitation of aortic regurgitation. Eight patients had an excellent result, three patients a good result, and three patients a fair result. One patient had a poor result because of persistent, severe aortic regurgitation. A small systolic pressure gradient was present across the homograft valve in 2 of 13 patients. Significant aortic regurgitation, defined as more than 3 L/min, occurred in four patients.

Patients with aortic regurgitation preoperatively had reduction in LV volume in proportion to the reduction in regurgitation after surgery. Left ventricular mass diminished postoperatively in proportion to the reduction in stroke work, as determined from the pressure-volume diagram.
Laboratory and Clinical Studies during Prolonged Partial Extracorporeal Circulation Using the Bramson Membrane Lung
Authors: HILL J. DONALD , BRAMSON M. L. , HACKEL ALVIN , DEAL CEDROC W. , SANCHEZ PEDRO A. , OSBORN JOHN J. , GERBODE FRANK
Published: June 2012

The survival rate, electrolyte changes, hematological changes, arterial gas analysis, and pulmonary compliances in 14 prolonged venovenous perfusions with the Bramson membrane oxygenator are presented. The Bramson membrane oxygenator functioned efficiently.

There were two deaths in the series, neither attributable to the perfusion. Arterial gas studies and pulmonary compliance studies indicated no measurable detrimental effect on the lungs. Platelet counts decreased and white blood cell counts increased during perfusion.

A clinical prolonged veno-venous perfusion is reported.
Epicardial Pacing to Control Arrhythmias Following Cardiac Surgery
Authors: HARRIS PAUL D. , MALM JAMES R. , BOWMAN FREDERICK O. , HOFFMAN BRIAN F. , KAISER GERARD A. , SINGER DONALD H.
Published: June 2012

Epicardial electrodes were chronically implanted on the surface of atria and ventricles in 60 patients at the time of open-heart surgery. Eighteen patients developed bigeminy or multiple premature ventricular contractions associated with slow heart rates in the immediate postoperative period. The ectopic ventricular activity was abolished by pacing the atria or ventricles faster than the spontaneous cardiac rate. In seven patients, low cardiac output associated with low heart rates was improved by pacing at more optimal rates.

When feasible, atrial pacing is preferred to ventricular pacing to utilize atrial systole to improve ventricular filling and increase cardiac output. The safety and ease of implantation of these electrodes enable them to be used routinely for diagnostic and therapeutic application in all patients undergoing open-heart surgery.
Mechanical Ventricular Assistance in Man
Authors: BAUE ARTHUR E. , TRAGUS EUGENE T. , ANSTADT GEORGE L. , BLAKEMORE WILLIAM S.
Published: June 2012

Mechanical cardiac massage by a pneumatic device which fits over the ventricles of the heart was studied in six patients with cardiac arrest who failed to respond to conventional means of resuscitation. Adequate arterial blood pressure, full peripheral pulses, respiratory efforts, small reactive pupils, reasonable cardiac output, and a low venous pressure were obtained for as long as four hours. In a 48-year-old patient ventricular fibrillation did not respond to external or internal massage and defibrillation in 35 minutes, and there was no ECG activity. With this instrument the circulation was supported for an hour (blood pressure 135/50). Defibrillation was then possible, and the patient survived for six days, dying of her primary disease process, which was unrelated to the heart. These studies are being continued and indicate that this approach may be helpful for cardiac resuscitation, for prolonged circulatory support, and for maintaining the circulation in potential donors for organ transplantation.
Femoropopliteal Bypass Grafts Utilizing Autogenous Veins
Authors: CALDWELL ROBERT L. , DEWEESE JAMES A. , ROB CHARLES G.
Published: June 2012

The results of 157 consecutive autogenous saphenous vein bypass grafts followed for periods up to eight and a half years are presented. The operations were performed on 145 patients with the following indications: (1) intermittent claudication (41%); (2) rest pain (25%); (3) gangrene (34%).

The early patency rate in patients with intermittent claudication was 83%, and of these 83% remained patent; with rest pain, 74% and of these 86% remained patent; with gangrene, 63% and of these 76% remained patent.

The success rate was highest in (1) nondiabetic patients; (2) extremities with two or three patent vessels at the level of the popliteal trifurcation; (3) extremities in which short grafts were used, whether or not the reconstruction crossed the knee joint.

Angiograms on 29 patent grafts and 12 thrombosed grafts revealed: (1) absence of atheromatous changes in the grafts; (2) absence of aneurysmal dilatation in the body of the graft; (3) an equal incidence of progression of original disease in patent grafts and in late thrombosed grafts.

Autogenous venous bypass grafts function well in the arterial system for prolonged periods. The results continue to support the superiority of vein grafts over both thromboendarterectomies and synthetic-tube bypass grafts in the treatment of femoropopliteal occlusive disease.
Erythrocyte Destruction by Prosthetic Heart Valves
Authors: INDEGLIA ROBERT A. , SHEA MICHAEL A. , VARCO RICHARD L. , BERNSTEIN EUGENE F.
Published: June 2012

Immediate hemolysis induced by eight aortic and five mitral valve prostheses was measured in in vitro steady- and pulsatile-flow systems. The mean index of hemolysis (IH) for the aortic valves ranged from 0.010 to 0.031 and 0.012 to 0.035 with steady and pulsatile flow, respectively. The IH for the mitral valves ranged from 0.004 to 0.021 in the steady-flow system, and from 0.011 to 0.021 in the pulsatile system.

The Barnard-UCT aortic valve and the Kay-Shiley and Portex-Hammersmith mitral valves produced the least hemolysis in each group. The graphite-benzalkonium-heparin-coated Gott-Daggett valve was the most hemolytic valve in both the mitral and the aortic groups.

The degree of hemolysis demonstrated in these experiments appears to be important, particularly since several factors which are likely to have minimized these data have been cited. The calculated daily hemoglobin released from a single prosthetic valve represents a substantial fraction of a human's total hemoglobin clearance capacity and red cell regenerative capability.
A Study of Mitral Valve Action Recorded by Reflected Ultrasound and Its Application in the Diagnosis of Mitral Stenosis
Authors: ZAKY ADIB , NASSER WILLIAM K. , FEIGENBAUM HARVEY
Published: June 2012

The movements of two ultrasound echo signals, believed to arise from the anterior mitral leaflet and from the mitral ring, were studied in 30 normal subjects and in 100 heart-catheterization patients. Fifty patients had proven mitral stenosis. The echo from the anterior mitral leaflet is shown to have a complex pattern of movement. This pattern is analyzed into the opening and closing movements of the leaflet, and the underlying movement transmitted from the mitral ring. In the normal condition, the characteristic feature of leaflet motion is a sharp closing movement that follows the initial opening in diastole. This sharp closing movement is not seen in the presence of mitral stenosis. It is believed that the demonstration of a sustained wide-open poisition of the leaflet in diastole has the same diagnostic significance as the finding of a persistent positive-pressure gradient across the valve. The value of this method in diagnosing the severity of the stenosis is discussed.
Tritiated Digoxin Excretion of Patients Following Renal Transplantation
Authors: DOHERTY JAMES E. , FLANIGAN WILLIAM J. , PERKINS WILLIAM H. , Gammill Jacquelyn , Sherwood Joyce
Published: June 2012

Four patients with a single allografted kidney were given 1.0 mg of tritiated digoxin intravenously. Compared with patients with two normally functioning kidneys, these patients exhibited increased digoxin serum levels, modestly reduced renal excretion, and increased stool excretion of digoxin during a 7-day study. When administration of digoxin is indicated for a patient with a renal transplant, it may be necessary to reduce the dose even though renal function appears to be adequate.
Left Atrial Rhythm
Authors: HARRIS BARRY C. , SHAVER JAMES A. , GRAY SAMUEL , KROETZ FRANK W. , LEONARD JAMES J.
Published: June 2012

Various criteria have been proposed for the diagnosis of left atrial rhythm (LAR) in previous experimental and electrocardiographic studies. Differentiation from A-V junctional rhythms remains ill-defined. In order to assess the left atrial (LA) P wave and to define LAR, the P wave and loop were studied by direct LA pacing in 11 patients undergoing diagnostic transseptal left heart catheterization. Experimental LAR produced changes in P-wave configuration and polarity. These changes were most obvious in lead V
1
and indicated reversal of the sequence and direction of activation with left atrial preceding right atrial depolarization. A typical "dome and dart" P wave occurred in two studies. P-wave configuration in leads I and V
6
was highly variable; frequent orientation of the LA P vector within the transitional zone of the horizontal electrical axis was thought to be responsible. The LA P loop showed reversal of the direction of inscription of the initial forces, indicating a change in the pattern of atrial depolarization. Stimulation of the appendage produced left-to-right spread of atrial depolarization, whereas activation of the main body was directed primarily anteriorly. Impulse formation in the right side of the posterior wall was usually directed from right to left. When the postero-inferior area was activated, the anterior P vector became directed superiorly, and resembled that of coronary sinus rhythm (CSR) in the frontal plane.

This study indicates that the P wave in lead V
1
is most important in the diagnosis of LAR; inversion of the P wave in lead V
6
is not essential. LAR can usually be differentiated from CSR, since in the horizontal plane, activation of the LA main body is more anteriorly directed than the spatial P vector of CSR.
Temporal Alternation of Atrial Flutter Sounds
Authors: EMSLIE-SMITH D. , PARRY E. H. O.
Published: June 2012

A case of atrial flutter is reported in which the hearing of "systoles en écho" led to the recognition in the phonocardiogram of a regularly alternating time interval between successive atrial sounds during the ventricular standstill caused by stimulation of the carotid sinus. A possible explanation is proposed involving alternating pathways of atrial excitation.
Incidence of Suppressed Renin Activity and of Normokalemic Primary Aldosteronism in Hypertensive Negro Patients
Authors: CREDITOR MORTON C. , LOSCHKY UNA K.
Published: June 2012

In 35 normokalemic Negro patients with benign essential hypertension, plasma renin activity (PRA) was measured by the method of Boucher and associates, while they were on regular diets, after ambulation, sodium restriction and thiazide medication, and again after rigid sodium depletion in the hospital. In nine (26%) inadequate PRA response was elicited even after the latter regimen. In only two of these (6%) was elevated excretion of aldosterone demonstrated. Suppressed PRA is commonly encountered in apparent benign essential hypertension and it occurs much more frequently than normokalemic primary aldosteronism does. Casual measurement of PRA in ambulatory patients is of little differential diagnostic value in primary aldosteronism.
Autoimmune Studies in Patients with Primary Myocardial Disease
Authors: FLETCHER, M.D. GERALD F. , WENGER NANETTE K.
Published: June 2012

Heart immunofluorescent autoantibody tests, the complement fixation test for Chagas' disease, the hemagglutination test for toxoplasmosis, and the latex flocculation test for rheumatoid disease were compared in 34 patients with primary myocardial disease and their paired control subjects. There was no difference in the incidence of elevated titers or in the actual titer levels between the group with primary myocardial disease and the control group for any of these tests.

This study is limited in that it gives no information about an agent or mechanism for primary myocardial disease which is no longer demonstrable by serological test, particularly since the patients with primary myocardial disease were studied, at an average, 6 years after onset of symptoms. It is also possible that agents or mechanisms other than those included in this study may be causative of primary myocardial disease.

We have, however, demonstrated that there is
no
serological evidence associating the parasites or immunological responses studied with the clinical syndrome of chronic primary myocardial disease.
Ultrastructure of the Human Atrioventricular Node
Authors: JAMES THOMAS N. , SHERF LIBI
Published: June 2012

Ultrastructure of the A-V node was studied in two human hearts. Fine details of intranodal cellular organization were then resynthesized on the basis of light microscopic examinations of over 250 human hearts. There are four different types of cells and no anatomic syncytium in the human A-V node: (1) a simple rounded cell identical to P cells of the sinus node, (2) a slender transitional cell which is by far the most numerous type in the A-V node, (3) Purkinie cells, and (4) ordinary working myocardium; both of the latter are almost exclusively at the nodal margins. The possible significance of these ultrastructural features relative to certain functions of the A-V node, such as pacemaking and delay of conduction, is discussed.
The Biology of Myocardial Infarction
Authors: BIÖRCK GUNNAR
Published: June 2012

Myocardial infarction is a dreaded companion of the civilization of our time. The "heart attack," the coronary thrombosis, the myocardial infarction lurk behind the corner, striking strangers, patients, friends, and ourselves. The toll taken by this single "disease" in many hospitals equals or even exceeds that from almost all other diseases together. Must it be so? This is the question many physicians, and the lay public, are asking themselves today.

Identification of some areas where our knowledge is particularly deficient is stressed. We must concentrate our efforts on reevaluating practices and procedures that have brought both the greatest success and the worst failures, at the same time that we ask ourselves what goals could be considered realistic.

If myocardial infarction is the evil of our time, what does this mean in a greater biological context-in the evolution of human life and endeavor as viewed in perspective? Are we dealing with a "disease" in the restricted sense of the word, or are we dealing with a way of life and a consequent mode of death? If so, what can be done to achieve the goals of health as defined by the World Health Organization? In what terrain are the forces to be assembled and the battle to be fought-and by whom.
Left Ventricular Pressure-Volume Characteristics in Congenital Heart Disease
Authors: JARMAKANI M. M. , EDWARDS SAM B. , SPACH MADISON S. , CANENT RAMON V. , CAPP M. PAUL , HAGAN MARY J. , BARR ROGER C. , JAIN VISHNU
Published: June 2012

The continuous pressure-volume relationships throughout the cardiac cycle were evaluated in children with tetralogy of Fallot, isolated ventricular septal defect, and patent ductus arteriosus. Biplane cineangiocardiography and simultaneous left ventricular pressures were utilized for data acquisition. Normal pressure-volume loops demonstrated only small changes in left ventricular volume during the isovolumic periods. In tetralogy of Fallot, there was a decrease in left ventricular volume during the interval of the "isovolumic" contraction with 12 to 43% of the total stroke volume being ejected during this phase. A decrease in left ventricular volume during this time was also found in large ventricular septal defects; however, volume changes during this interval were minimal in those patients judged to have small defects.

With large left-to-right shunts of comparable magnitude, the relative area of the pressure-volume loop was greater in patent ductus arteriosus as compared with ventricular defects. Both conditions demonstrated marked increase in stroke volume, with peak systolic pressures rising higher in those patients with patent ducus arteriosus as compared to those with ventricular septal defect.
The Apexcardiogram in Myocardial Asynergy
Authors: LANE FRANCIS J. , CARROLL JOHN M. , LEVINE HAROLD D. , GORLIN RICHARD
Published: June 2012

The apexcardiogram was analyzed in 41 patients with an altered pattern of left ventricular contraction. Four types were distinguished: type I, an early sustained systolic bulge which occurred in 12 patients, all of whom had large aneurysms and large enddiastolic volumes; type II, a bulge confined to midsystole which occurred in 13 patients, 11 of whom had some form of ventricular asynergy; type III, a late or end-systolic bulge which occurred in 12 patients, seven of whom had ventricular asynergy; type IV, a prominent spike during diastolic filling which occurred in four patients who had large zones of ventricular asynergy.
Evaluation of Operative Left Ventricular Outflow Tract Lesions with a Fluid Impedance Plot
Authors: SPENCER MERRILL P. , EDMUNDS L. HENRY
Published: June 2012

A hydraulic fluid impedance plot is produced by plotting instantaneous differential pressure against phasic blood flow across a vascular segment. This simple plot quantitatively and compactly describes the changes in flow resistance (impedance) throughout the entire cardiac cycle. Impedance plots were obtained before and after corrective surgery in patients with a variety of left ventricular outflow tract and aortic valve lesions. Although present techniques are still limited, impedance plots now provide quantitative measurement of flow resistance throughout the cardiac cycle in a variety of cardiac and great vessel lesions.
Disparities Between Aortic and Peripheral Pulse Pressures Induced by Upright Exercise and Vasomotor Changes in Man
Authors: ROWELL LORING B. , BRENGELMANN GEORGE L. , BLACKMON JOHN R. , BRUGE ROBERT A. , MURRAY JOHN A.
Published: June 2012

Blood pressures were recorded simultaneously from the aortic arch and radial artery using two manometric systems with identical static and dynamic sensitivities. Measurements were made in four normal young men at rest and upright exercise requiring 29, 49, 78, and 100% of maximal oxygen uptake. Average radial arterial pressure rose from 133/66 mm Hg at rest to 236/58 mm Hg at maximal exercise. At the same time, average aortic pressures were 112/68 and 154/70 mm Hg, respectively. From rest to maximal exercise, pulse pressures at central and peripheral sites increased by factors of 1.95 and 2.60, respectively. Inducing reactive hyperemia in the arm abolished peripheral amplification. This amplification also diminished with time during prolonged heavy exercise. Mean pressures were nearly identical at the two sites at any oxygen uptake; mean pressures rose from 87 to 104 mm Hg from mild to maximal exercise. We conclude that estimates of stress on aortic and cerebral vessel walls and central baroreceptors would be grossly overestimated by use of peripheral pulse pressures.
Congenital Aneurysm (Diverticulum) of the Right Atrium
Authors: MORROW ANDREW G. , BEHRENDT DOUGLAS M.
Published: June 2012

A patient is described in whom a large congenital aneurysm or diverticulum of the right atrium caused repeated attacks of supraventricular arrhythmia and a strikingly reduced cardiac output. The aneurysm, which contained a large thrombus, was demonstrated by preoperative angiographic examinations. At the time of operation, regular rhythm returned at the moment the aneurysm was transsected. The patient is asymptomatic after operation, and has maintained sinus rhythm. A normal cardiac index was recorded at postoperative cardiac catheterization.
Atrioventricular Pressure Half-Time
Authors: LIBANOFF ALBERT J. , RODBARD SIMON
Published: June 2012

In 20 patients studied by cardiac catheterization, the time required for the diastolic left atrioventricular pressure difference to fall to half its initial value (half-time) varied with the anatomic severity of the valvular stenosis. In mild mitral stenosis, the half-time was approximately 100 msec; in moderate stenosis, it was about 200 msec; and it was 300 msec or longer in severe stenosis. The half-time at the nonstenotic mitral valve was less than 25 msec.

Although exercise increased the atrioventricular pressure gradient, heart rate, and cardiac output significantly, the half-time was affected only slightly. Mitral regurgitation of various severities did not affect the half-time. The half-time appears to vary inversely with the anatomic orifice area of the mitral valve. The determination of the half-time obviates the need for the commonly used exercise test for the evaluation of mitral stenosis.
Effect of Acute Intravenous Administration of Isoproterenol on Cardiorenal Hemodynamics in Man
Authors: ROSENBLUM ROBERT , BERKOWITZ WALTER D. , LAWSON DIANA
Published: June 2012

By the direct Fick, or the indocyanine-green or both, methods and by renal clearance of inulin and para-aminohippurate (PAH), simultaneous cardiorenal hemodynamic observations were made before and during isoproterenol infusion (0.9-2.6 µg/ min) into three patients without, and 10 patients with, heart disease. Although a consistent increase in cardiac output (11 to 147%) was noted in all patients, no significant change in glomerular filtration rate or renal blood flow was observed. The percentage of the cardiac output delivered to the kidney during drug infusion decreased in all subjects. The renal extraction of PAH, measured in three patients, was not changed during isoproterenol administration. The infusion of isoproterenol to normovolemic and hypervolemic dogs (10 dogs) increased the cardiac output in all animals but produced no significant change in glomerular filtration rate or renal blood flow. Because the renal blood flow is not affected by the increased cardiac output produced by isoproterenol, the data suggest that there is either a weak or an absent beta-receptor response in the kidney in the dog and man.
Correlation of Vectorcardiogram and Electrocardiogram with Coronary Arteriogram
Authors: LEE GERALD B. , WILSON WILLIAM J. , AMPLATZ KURT , TUNA NAIP
Published: June 2012

One hundred patients with suspected coronary heart disease were studied by vectorcardiography (VCG), electrocardiography (ECG), and coronary arteriography. Twenty-eight patients had VCG evidence of anterior infarction; 26 of this group had severe narrowing or obstruction of the left anterior descending branch. Five did not have anterior infarction by ECG.

Twenty-seven patients had VCG evidence of diaphragmatic infarction; 25 of this group had severe narrowing of the right coronary artery or the left circumflex branch or both. Six of the 27 did not have ECG evidence of diaphragmatic infarction.

Twelve patients had VCG evidence of posterior infarction whereas it was detected by ECG in only two. Only six of the 12, however, had severe narrowing of the nutrient arteries to the posterobasal part of the myocardium.

Thirteen patients with infarction had severe narrowing but not total obstruction of a coronary artery. On the other hand, 15 patients had total obstruction of a major coronary vessel without actual infarction.
Tetralogy of Fallot
Authors: IKEDA MASAO , HIROSAWA KOSHICHIRO
Published: June 2012

Although the natural course of tetralogy of Fallot is not yet clear, the life-span seems to be short except in rare cases of mild pulmonary stenosis or in cases associated with a sizeable systemic-pulmonary anastomosis. Two hundred and nine patients with tetralogy of Fallot underwent operation in the Department of Thoracic Surgery, University of Tokyo. The Blalock-Taussig operation was performed in 137 patients between 1951 and 1965. Total surgical mortality was 9% (3.5% in recent years). Analysis of 124 patients surviving an average of 5.5 years postoperatively showed that 45% of patients were still doing well, 4% had fair results, 12% exhibited no improvement, 15% required a second operation (either a second anastomosis or total correction), and 10% died of cerebral embolism, cardiac failure, or other causes (there are no details on the remaining 5% who survived). Total correction was carried out in 72 patients between 1955 and 1965. In nine of these cases, a shunt procedure had been performed previously. Total surgical mortality was 50% (19% in recent years). Surgical mortality of total correction from the world literature has fallen impressively due to improvement of surgical technique and selection of patients, but it is still higher than that of the Blalock-Taussig operation. Clinical improvement of 36 surviving patients, however, was much greater and more complete after total correction than after the Blalock-Taussig operation, although final evaluation of total correction must await long-term follow-up studies. Functional capacity and exercise tolerance have improved in the great majority of patients after total correction. Arterial oxygen saturation, hemoglobin concentration, and the hematocrit value have returned to normal values in almost all cases.
Hemodynamic Studies Before and After Instrumental Mitral Commissurotomy
Authors: FEIGENBAUM HARVEY , LINBACK RICHARD E. , NASSER WILLIAM K.
Published: June 2012

Hemodynamic studies including simultaneous right heart, transseptal left heart, and retrograde left heart catheterizations were done on 35 patients before and at least 6 months after instrumental mitral commissurotomy to evaluate the efficacy of this type of surgery and to enhance our understanding of the pathophysiology of mitral stenosis. Although surgery produced a significant increase in calculated mitral valve area, the degree of improvement varied markedly. The younger patients had the greater increase in mitral valve area. The change in cardiac index and pulmonary vascular resistance correlated well with the change in mitral valve area. Only those patients whose mitral valve area increased over 1.0 cm
2
had a significant increase in cardiac index and a fall in pulmonary vascular resistance. The data indicate that the reduced cardiac index and elevated pulmonary vascular resistance in patients with mitral stenosis are related to the mitral valve obstruction and are at least in part reversible and that the elevated pulmonary vascular resistance during mild exercise is related to elevated left atrial pressure.

An almost universal fall in left atrial and pulmonary artery pressures followed surgery, but this apparent improvement did not necessarily correlate with an increase in mitral valve area. A significant increase in exercise left ventricular end-diastolic pressure in patients who had the greatest increase in mitral valve area raises the question as to the status of the left ventricle in patients with mitral stenosis. Decreased left ventricular compliance is offered as a possible explanation for this observation.

The concomitant existence of mild or moderate preoperative aortic insufficiency in eight of the patients and the development of significant mitral insufficiency in seven of the 35 patients following surgery did not alter the surgical results significantly. Whether the poorer results in patients with atrial fibrillation were a result of age or the arrhythmia could not be determined.
Transposition of the Great Vessels with Hypoplasia of the Right Ventricle
Authors: RIEMENSCHNEIDER THOMAS A. , VINCENT WILLIAM R. , RUTTENBERG HERBERT D. , DESILETS DONALD T.
Published: June 2012

Eight cases are reported in which complete transposition of the great vessels was associated with varying degrees of hypoplasia of the right ventricle. In three, the correct diagnosis was suspected on the basis of certain electrovectorcardiographic findings and confirmed by selective angiography. Quantitative analysis of ventricular volumes and valve circumferences demonstrated that these cases represent a distinct pathological entity.

The diagnosis of complete transposition with hypoplastic right ventricle may be suggested by electrocardiographic evidence of left ventricular hypertrophy, relative absence of right ventricular QRS vectors, and leftward axis for age. The vectorcardiogram reveals a counterclockwise QRS loop in the horizontal plane, situated to the left and posteriorly. These findings occur infrequently in the young infant with complete transposition.

The presence of a hypoplastic right ventricle is confirmed by angiography, which demonstrates a small right ventricular chamber located centrally in the cardiac silhouette, not extending beyond the left border of the thoracic spine.
Spinnaker Formation of Sinus Venosus Valve
Authors: JONES RONALD N. , NILES NELSON R.
Published: June 2012

A persistent right valve of the sinus venosus fatally complicated a case of tricuspid atresia in a 10-year-old boy. The center of this large membrane stretched to form a sac resembling a spinnaker. Depending on the relative amounts and directions of blood flowing against it from the coronary sinus below and the venae cavae above, the sail might fill or empty quickly. This gave means of potential obstruction: either of coronary venous flow which, without a tricuspid valvular orifice, could be trapped beneath the membrane; or of all right atrial flow if the sac fell across the sole atrial outlet, the septal defect. Such episodic block caused syncope six times in the last 23 months of life and death in acute right heart failure.
Hemolytic Anemia Due to Progressive Enlargement of Silastic Ball Component of Aortic Prosthesis
Authors: GARCIA MARIO C. , CLARYSSE ALBERT M. , ALEXANDER CARL S. , SAKO YOSHIO , SWAIM WILLIAM R.
Published: June 2012

The patient described developed hemolytic anemia following insertion of a Starr-Edwards aortic valve prosthesis. No diastolic murmur was heard and no insufficiency was detected. The hemolytic anemia was progressively more severe and uncompensated despite various medical measures.

The anemia was characterized by fragmented erythrocytes in the peripheral blood, reticulocytosis, elevation of plasma heme pigments augmented by exercise, increased fecal urobilinogen, and iron loss in the urine. Studies of chromium-51-tagged erythrocytes indicated an extracorpuscular mechanism of hemolysis.

At reoperation the ball component of the prosthesis was found to be enlarged and obstructing blood flow. Chemical analysis of the ball showed significant cholesterol and lipid deposits. The hemolysis disappeared after the prosthesis was replaced with a homograft valve. Ferrokinetic studies showed rapid plasma clearance and incorporation into circulating erythrocytes. Triglycerides were elevated during the period of hemolysis. Red cell membrane lipids were normal.
Myocardial Infarction After Normal Responses to Maximal Exercise
Authors: BRUCE ROBERT A. , HORNSTEN TOM R. , BLACKMON JOHN R.
Published: June 2012

The unexpected occurrence of acute myocardial infarction shortly after performance of a multistage test of maximal exercise by a normal 42-year-old subject is described. There was no evidence of infarction after this exhausting effort, but symptoms occurred immediately on exposure to hot water while he was taking a shower a few minutes later. Cardiac arrest from ventricular fibrillation occurred after ECG evidence of acute infarction. Following successful defibrillation and coronary care, there was satisfactory recovery from massive anterior wall infarction. Incidence, possible pathophysiological mechanisms, and precautions are cited.
Multifactorial Inheritance Hypothesis for the Etiology of Congenital Heart Diseases
Authors: NORA JAMES J.
Published: June 2012

A systematic investigation into the etiology of congenital heart diseases (CHD) has been undertaken through the testing of four alternative hypotheses. Data was obtained for six common congenital heart lesions from the investigation of familial aggregates, twin studies, and chromosomal evaluations. Animal homologies were also considered in the evaluation of the hypotheses. Hypothesis 1—no genetic basis for the etiology of congenital heart diseases—was tested and rejected. Then in an effort to define the possible genetic basis of congenital cardiovascular malformations hypothesis 2—the genetic basis of CHD is determined by gross chromosomal aberrations—was evaluated by reviewing karyotypes of nonsyndrome CHD patients in the literature as as well as 104 personal cases. Rejection of hypothesis 2 is required by all available evidence. Hypothesis 3—the genetic basis of common isolated congenital heart lesions is determined by single mutant genes—was also tested and rejected.

Hypothesis 4—congenital heart diseases are a heterogeneous category of developmental anomalies, representing in most cases the multifactorial inheritance of threshold characters, the expression of which is the product of a genetic-environmental interaction—was tested by the same criteria. On the basis of these criteria this hypothesis could
not
be rejected.

Therefore the multifactorial hypothesis is proposed as a working hypothesis which encompasses both the genetic and environmental factors known to participate in the etiology of congenital heart diseases. It is hoped that through the testing of this hypothesis investigation into new areas will be stimulated, which ultimately will lead to active methods of prevention.
Two Types of Intraventricular Pressure Difference in the Same Patient
Authors: ADELMAN ALLAN G. , WIGLE E. DOUGLAS
Published: June 2012

Two types of intraventricular pressure difference were encountered in a single patient who presented with clinical evidence of obstruction to right ventricular outflow and nonobstructive cardiomyopathy of the left ventricle. On the basis of measurements of inflow tract pressure, the pressure difference in the right ventricle was demonstrated to be due to muscular subvalvular obstruction to right ventricular outflow, whereas the pressure difference in the left ventricle resulted from catheter entrapment in the myocardium. This combination of intraventricular pressure differences must be differentiated from the situation in muscular subaortic stenosis, in which biventricular obstruction to outflow occurs.
Homograft Replacement of the Mitral Valve
Authors: GIANELLY RALPH E. , ANGELL WILLIAM W. , STINSON EDWARD , SHUMWAY NORMAN E. , HARRISON DONALD C.
Published: June 2012

Replacement of the mitral valve with an aortic valve homograft has become feasible. Clinical and hemodynamic assessments of eight patients who received the new homograft were made from 3 to 6 months following surgery. Marked improvement was reported by six patients and mild to moderate improvement by two. At rest the homografts functioned well, creating a trivial diastolic gradient between the left atrium and left ventricle and being mildly insufficient in two cases. On exercise there was moderate mitral insufficiency. Anticoagulants were used for 3 months following surgery and then discontinued. In 60 subsequent patient-months no thromboembolism has been observed. The data are as yet inconclusive, but the homograft shows promise of being a reasonable alternative to the prostheses currently in use.
Acute Myocardial Infarction Secondary to Thromboembolism from a Fractured Prosthetic Aortic Valve
Authors: GOBEL FREDARICK L. , HAWKINS HENRY M. , HANSON RUSSELL , WANG YANG
Published: June 2012

A case of coronary artery embolism from thrombus in a fracture in an aortic Starr-Edwards prosthesis was documented at necropsy. This 40-year-old white man had replacement of the aortic and mitral valves by ball-valve prostheses 5 years prior to his death. Following surgery, he was able to return to full-time work. He did not return for follow-up for 2 years, and when next seen he had an acute myocardial infarction and left ventricular failure. An embolus to the left anterior descending coronary artery was demonstrated at the postmortem examination. The mitral ball was intact, but the aortic ball had two large fractures which contained thrombi.
Computer Quantitation of the ST-Segment Response during Maximal Treadmill Exercise
Authors: MCHENRY PAUL L. , STOWE DARWELL E. , LANCASTER MALCOLM C.
Published: June 2012

The ST-segment response during maximal treadmill exercise was quantitated by digital computer after excessive noise in the electrocardiographic data was reduced by computer averaging. Both the slope and the depression were quantitated.

Two groups of subjects were studied. Group A consisted of 35 subjects between 33 and 57 years of age with confirmed or suspected coronary artery disease. Group N consisted of 73 clinically normal subjects between 24 and 52 years of age. The responses of the group A subjects and the 26 subjects over age 35 in group N were compared by graphically plotting their ST slope and depression values from the last minute of exercise. A linear discriminant analysis computed from these values resulted in a line of separation between the majority of subjects in each of these two groups. This separation was accomplished even though the majority of subjects in group A did not demonstrate segmental ST depression.
Primary Subclavian-Axillary Vein Thrombosis
Authors: SWINTON NEIL W. , EDGETT JOSEPH W. , HALL ROBERT J.
Published: June 2012

Primary thrombosis of the subclavian-axillary vein is a condition of uncertain origin resulting in proximal arm swelling, discomfort on use, and prominence of engorged collateral veins in the upper arm and chest. The literature is reviewed and the authors' own experience with 23 patients, evaluated from 1950 through 1966, is detailed. This disorder is a clinically distinct venous complication of the neurovascular compression syndrome of the upper extremity. Contrary to the findings recorded by others, spontaneous improvement following conservative management, while initially good, ceases after the first few months. After a mean follow-up period of 8 years, nine patients have major, and 12 have minor, residual symptoms when using the affected arm. Venous collateral patterns persist in all patients. Early venography and thrombectomy are proposed.
Diastolic Murmurs in Apparently Normal Children
Authors: LIEBMAN JEROME , SOOD SANTOSH
Published: June 2012

Diastolic murmurs have always been considered abnormal, but this report presents nine apparently normal children with high-frequency, early, diamond-shaped diastolic murmurs confirmed by intracavitary phonocardiography to arise within the left ventricle. Each child (aged 5 to 15 years) was referred for evaluation of a systolic murmur at the lower left sternal border, but an additional finding at the initial examination was a grade I to III/VI high-pitched diastolic murmur, thought to be decrescendo, at the third and fourth intercostal space at the left sternal edge. The murmurs were best heard when the patient was supine. Cardiac x-rays, including four views with barium, were all clearly normal, as were eight of the nine electrocardiograms and the Frank and McFee vectorcardiograms. Multiple parameters of right and left heart catheterizations were normal in all.
Experimental Myocardial Infarction in Dogs
Authors: NAKHJAVAN FRED K. , SHEDROVILZKY HECTOR , GOLDBERG HARRY , Hampson James , Cuesta Angel
Published: June 2012

A closed chest technique for production of myocardial infarction in dogs is described. After isolation of the left carotid artery, selective coronary cineangiography is performed. A guide wire is then inserted into the catheter and advanced into the circumflex or anterior descending branch of the left coronary artery. The catheter is temporarily removed. A specially designed, siliconized, stainless steel cylinder is then inserted over the guide wire. The catheter is reinserted and is used to push, direct, and lodge the stainless steel cylinder into the anterior descending or the circumflex artery. The dogs are heparinized before, and for 3 days subsequent to, constriction. Ventricular arrhythmias are treated with procainamide. Coronary cineangiograms and serial electrocardiograms are obtained after coronary artery constriction. This technique provides an accurate model for research in the field of myocardial infarction.
Characterization of Left Heart Volumes and Mass in Normal Children and in Ifants with Intrinsic Myocardial Disease
Authors: GRAHAM THOMAS P. , JARMAKANI M. M. , CANENT RAMON V. , CAPP M. PAUL , SPACH MADISON S.
Published: June 2012

Quantitation of myocardial volumes, mass, and ejection fractions was performed in a group of 26 patients (10 of whom were infants less than 2 years old) with normal left ventricles and in a separate group of 13 children with intrinsic myocardial disease and clinical decompensation. All patients were studied by use of biplane cineangiocardiography, and volumes were determined by the area-length method. Left ventricular end-diastolic volume in "normal" infants below 2 years of age was 44.8 ± 8.5 cc/m
2
, and it was 71.4 ± 8.0 cc/m
2
in older normal children (
P
<0.001), ages 3 to 16 years. Left ventricular ejection fraction also was different in the younger normals: 0.76 ± 0.07 versus 0.63 ± 0.05 in older normals (
P
<0.001). Left ventricular mass and left atrial maximal volume were not significantly different in normal infants and older children, averaging 81.7 ± 10.0 g/m
2
and 33.6 ± 10.1 cc/m
2
, respectively. All patients in the cardiomyopathy group had significant elevations of left ventricular end-diastolic volume and mass, and the ejection fraction was reduced in all patients except one infant with severe mitral insufficiency. Five infants with chronic left ventricular failure and no mitral insufficiency had normal left atrial maximal volumes. Left atrial maximal volumes were increased significantly in six patients with myocardial disease, all of whom had mitral insufficiency. These results emphasize the potential value of the quantitative estimation of left heart volume and provide normative base-line data for left heart volume and mass parameters in both infants and children.
The Conduction System in Acute Myocardial Infarction Complicated by Heart Block
Authors: SUTTON RICHARD , DAVIES MICHAEL
Published: June 2012

Detailed histological examination of the conduction system in 29 cases of acute myocardial infarction complicated by heart block has been carried out. In 24 cases posterior infarction was present and occlusion had occurred in the artery from which the blood supply to the A-V node was ultimately derived. In these cases major structural damage to the conduction system was rare, but when present, involved the bundle branches. A-V block in posterior infarction is therefore usually due to hypoxia or other reversible factors rather than structural damage to the conduction system. These findings are consistent with the high incidence of transient heart block in survivors.

In five cases anterior infarction alone was present. The blood supply of the A-V node was not compromised, but massive infarction had caused major damage to both bundle branches.

Since major structural damage to the conduction system is uncommon in myocardial infarction, only a minority of survivors will have permanent heart block. In those cases in which there is extensive damage to the bundle branches there is a risk of high mortality and permanent block particularly when the infarct is anteroseptal.
Paradoxical Use of a Demand Pacemaker in Treatment of Supraventricular Tachycardia Due to the Wolff-Parkinson-White Syndrome
Authors: RYAN GERALD F. , EASLEY ROBERT M. , ZAROFF LAWRENCE I. , GOLDSTEIN SIDNEY
Published: June 2012

This paper describes a new technique for terminating attacks of supraventricular tachycardia in a patient with Wolff-Parkinson-White syndrome by using a demand pacemaker. The circuitry of this demand pacemaker generator is designed so that a magnet held near the generator converts the unit from demand to fixed mode at a pre-set discharge rate of 72/min. During an attack of tachycardia, a magnet held near the generator pocket activates a fixed rate discharge and produces competitive pacing. Retrograde atrial depolarization occurs with resultant reversion to sinus rhythm.
Differential Uric Acid Excretion in Essential and Renal Hypertension
Authors: SIMON NORMAN M. , SMUCKER JON E. , O'CONOR VINCENT J. , DEL GRECO FRANCESCO
Published: June 2012

In 59 hypertensive patients, differences between the two kidneys in the handling of uric acid were found in renal arterial stenosis and unilateral renal disease but were not found in essential hypertension and bilateral renal parenchymal disease. The differences were greatest in 11 patients with unilateral renal arterial stenosis and were derived from reduced uric acid excretion per unit of glomerular filtration rate by the ischemic kidney. Six patients with unilateral stenosis underwent surgery with subsequent cure of hypertension. Another patient, who did not have impaired ipsilateral uric acid excretion, failed to respond to nephrectomy. Successful revascularization of the ischemic kidney in two patients augmented uric acid excretion with disappearance of the differences between the kidneys. Hyperuricemia was often found in all groups of hypertensive patients. Although the mechanisms underlying the differences in renal handling of uric acid are undefined, separate determinations of the uric acid excretion by the two kidneys may possibly prove useful in the evaluation of patients with hypertension.
Thermistor Recording of Forehead Skin Temperature as an Index of Carotid Artery Disease
Authors: CONRAD MARGARET C. , TOOLE JAMES F. , JANEWAY RICHARD
Published: June 2012

Skin temperatures were recorded from the medial upper orbital area and above the nasal, mid and lateral portions of the brows in normal subjects and in patients with suspected cerebrovascular disease. Temperatures were reduced across the brow in patients with external carotid artery disease. Temperatures were lower than normal in the orbit in patients with internal carotid artery disease except when the internal carotid circulation was severely compromised. In such patients the supraorbital temperature was higher than normal, suggesting significant reversed flow via the supraorbital artery. With internal carotid occlusion, lateral brow temperatures suggested increases in external carotid flow. The interpretation of results was more reliable when temperatures were compared to normal values than when they were judged as differences between the two sides as is done in thermography.