bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Chlorothiazide on Renal Hemodynamics
Authors: VILLARREAL HERMAN , REVOLLO ANDRÉS , EXAIRE JOSÉ EMILIO , LARRONDO FRANCISCO
Published: June 2012

A comparative study was made of the acute effect of chlorothiazide upon renal hemodynamics in eight normotensive subjects and 10 patients with early essential hypertension.

It was observed that blood pressure remained unchanged in normotensive subjects but was significantly reduced in hypertensive patients. Glomerular filtration rate was decreased similarly in both groups, whereas renal plasma flow was not modified in either. Osmotic clearance increased in all subjects, free water clearance diminished in normotensive (overhydrated) subjects, whereas in the hypertensive (not overhydrated) patients free water reabsorption increased.

It is concluded that chlorothiazide reduces blood pressure in hypertensive patients but not in normotensive persons; that the kidney reacts in the same fashion in normotensive and hypertensive subjects under the action of the drug; and that the alterations in renal function observed with its use in hypertensive subjects are probably unrelated to changes in blood pressure.
The Diagnosis of Bilateral Stenosis of the Primary Pulmonary Artery Branches Based on Characteristic Pulmonary Trunk Pressure Curves
Authors: AGUSTSSON M. H. , ARCILLA R. A. , GASUL B. M. , BICOFF J. P. , NASSIF S. I. , LENDRUM B. L.
Published: June 2012

The cardiac catheterization and angiocardiographic findings in 12 cases with bilateral stenosis of the primary pulmonary artery branches are described. Characteristic pressure tracings were consistently obtained from the main pulmonary trunk in all cases. These typical curves were reproduced in animal experiments. Associated lesions with left-to-right shunts and mild pulmonary valvular stenosis did not alter the characteristics of the curves. An attempt is made to explain these hemodynamic phenomena.

These tracings obtained from the main pulmonary trunk appear to us to be diagnostic of bilateral stenosis of the main pulmonary arteries even if, as frequently happens, one is unable to enter both pulmonary artery branches during cardiac catheterization or to demonstrate definitely the stenosis of both pulmonary arteries by angiocardiography.
Studies on Starling's Law of the Heart
Authors: AYGEN MAURICE M. , BRAUNWALD EUGENE
Published: June 2012

This investigation was designed to study the mechanical properties of human myocardium in vivo, and to ascertain whether Starling's law applies to the human ventricle by determining whether the length of a segment of myocardium influences its force of contraction. A modified Walton-Brodie strain-gauge arch was sewn to the right ventricle of 10 patients and to the left ventricle of one patient at the time of operation. This instrument permitted the controlled alteration of the length of the myocardial segment to which it was attached, as well as the measurement of the tension exerted by this segment of myocardium throughout the cardiac cycle. In all 11 patients studied it was noted that as myocardial length was increased, the end-diastolic tension tended to rise slightly at first, but with further stretching the end-diastolic tension increased more strikingly. As the segment was stretched the maximal systolic tension, which it developed, increased more than did its resting tension. Thus, within limits, the active or developed tension rose as the myocardial segment increased in length. In five patients the active tension declined after the myocardial segment had been stretched to values ranging between 15 and 50 per cent above baseline length, i.e., a descending limb of the length-active tension relationship was evident. No change in duration of active tension occurred with progressive stretching of the myocardial segment, and changes in the rate of development of tension paralleled the changes in the active tension. In six patients the segment of myocardium was stretched progressively and was then permitted to shorten in the opposite direction. Hysteresis of the myocardium was demonstrated, since, at any given myocardial segment length, the resting and the maximal tensions were higher when the segment was being lengthened than when it was being shortened. These observations provide a description of the mechanical properties of functioning human myocardium and indicate that this tissue behaves in accordance with the Frank-Starling principle.
Electrocardiogram and Spatial Vectorcardiogram of Localized Myocardial Hypertrophy
Authors: BURCH GEORGE E. , DEPASQUALE NICHOLAS P.
Published: June 2012

Diagnostic electrocardiographic and vectorcardiographic manifestations of localized hypertrophy of the posterobasal portion of the left ventricle and of localized hypertrophy of the crista supraventricularis have been described. Recognition of the fact that only a portion of the myocardium may undergo hypertrophy is important in understanding certain types of electrocardiographic and spatial vectorcardiographic patterns.

Several types of localized myocardial hypertrophy for which no characteristic electrocardiographic or spatial vectorcardiographic patterns have been described were also discussed. There is a need for further study of this problem, and, in particular, for detailed correlation of the necropsy data with the electrocardiogram and the vectorcardiogram.
Congenital Stenosis of Individual Pulmonary Veins
Authors: SHONE JOHN D. , AMPLATZ KURT , ANDERSON RAY C. , ADAMS PAUL , EDWARDS JESSE E.
Published: June 2012

The case is reported of an infant with congenital stenosis of each of the four individual pulmonary veins near the left atrium. The characteristic features were failure to thrive, increasing cyanosis and dyspnea, and death in congestive cardiac failure at 7 months of age. A precordial systolic murmur and an early systolic ejection click were heard; the sounds over the base of the heart were diminished in intensity. Roentgenograms of the thorax revealed a heart of normal size with fullness of the main pulmonary artery segment and increased pulmonary vascular markings that had the reticulated appearance associated with pulmonary venous engorgement. Electrocardiography showed right axis deviation, right atrial enlargement, and a pattern of right ventricular systolic overload. Cardiac catheterization demonstrated increased right atrial pressure and markedly elevated right ventricular and pulmonary arterial pressures. Angiocardiographic studies revealed a right-to-left shunt at atrial level, enlargement of the right ventricle, and enlarged and tortuous pulmonary arteries. In the late films the left atrium appeared normal in size, but the pulmonary veins were tortuous and there was evidence of constriction of the pulmonary veins at the veno-atrial junctions, associated with delay in the passage of opaque material from the pulmonary veins to the left atrium.

It is suggested that the definitive diagnosis most likely is to be made by a selective angiocardiogram performed from the main pulmonary artery.

It would appear feasible, at least in theory, to obtain complete surgical correction of this anomaly.
Structure of the Cell Surface
Authors: DANIELLI J. F.
Published: June 2012

A personal view of the growth of ideas about the structure of the plasma membrane.
The Natural History of Atherosclerosis
Authors: VASTESAEGER MARCEL M. , DELCOURT R.
Published: June 2012

In order to complete the fragmentary knowledge of the natural history of atherosclerosis, the authors examined the coronary arteries of 403 captive and 146 wild vertebrates living in freedom, as well as the aortas of 134 of them. In 88 of the captive animals and in 51 of the free individuals, lipidogram, total cholesterol, beta-cholesterol and cholesterol/phospholipid ratio were also determined.

In this material, spontaneous atherosclerosis always developed in arteries already impaired by intimal sclerosis, and intimal sclerosis seems to be a basic condition for spontaneous atherogenesis.

Lipid deposits were found in the intima of 29 per cent of the examined aortas, but coronary atherosclerosis was present in only 2 per cent of the captive specimens. The discovery of coronary atherosclerosis in free tunny fishes, caught in the Bay of Biscay, brings proof that atherosclerosis is neither the privilege of warm-blooded vertebrates nor a consequence of captivity.

Unfortunately, the material collected does not permit even a rough estimate of the influence of captivity on the development of atherosclerosis. It was observed in any case that captivity significantly alters some aspects of the lipidic metabolism in animals, and especially the beta-lipoprotein levels as well as the beta-cholesterol fraction.

Spontaneous atherosclerosis may develop in fishes living in their natural habitat, feeding on a diet rich in unsaturated fats; in captive birds whose dietary fats are mostly unsaturated (crane, tree duck, pelican); and in wild mammals whose diet is free of animal fats, in freedom as well as in captivity (deer, camel, tapir).
The Acid-Base Vector of Open-Heart Surgery
Authors: PUYAU FRANCIS A. , FOWLER RICHARD E. L. , NOVICK ROSALIND , ALBERT HAROLD , GLASS BERT
Published: June 2012

Fourteen patients submitted to open-heart surgery were studied by serial acid-base and electrolyte determinations in order to demonstrate the sequence and magnitude of disturbances associated with the procedure. Under conditions of the study, including the use of 100 per cent oxygen as the perfusing gas for the oxygenator, respiratory alkalosis develops as the initial change during perfusion but is followed by a "metabolic shift" characterized by falling pH and CO
2
content, while a stable, moderately low pCO
2
is maintained by the oxygenator. The resulting state of mixed respiratory alkalosis and metabolic acidosis changes into a state of relatively pure metabolic acidosis as pCO
2
and bicarbonate content rise while pH falls after perfusion. The factors involved in the "metabolic shift" responsible for development of metabolic acidosis are not identified by this study although length of perfusion, perfusion pressure, and rate of flow are considered as possible factors. Acidosis persists through the early phases of the recovery period but ordinarily resolves without administration of alkali. Serial sampling technics as used in this study may aid in the interpretation of postoperative acidosis, distinguishing between patients who are deteriorating and those who are passing through a transient phase in the process of recovery.
Acquired Pulmonic Stenosis
Authors: BABCOCK KENNETH B. , JUDGE RICHARD D. , BOOKSTEIN JOSEPH J.
Published: June 2012

Acquired pulmonic stenosis is rare. A well-documented case of pulmonary infundibular stenosis due to mediastinal lymphoma has been described. Complete disappearance of the heart murmur followed therapy with nitrogen mustard. Other causes of acquired pulmonic stenosis have been discussed.
The Two-Step Exercise Electrocardiogram
Authors: FRIEDBERG CHARLES K. , JAFFE HARRY L. , PORDY LEON , CHESKY KENNETH
Published: June 2012

A double-blind study was made to evaluate the two-step exercise electrocardiographic test (Master) as a means of differentiating between anginal and nonanginal chest pain in 100 consecutive patients.

A high percentage of false-positive results in nonanginal cases and a number of false negatives in anginal cases greatly impaired the usefulness of the test for this purpose.

When Master's criterion of an ST depression of 0.5 mm. or more was employed, there were 39 per cent false positives and 12 per cent false negatives.

Stricter criteria progressively diminished the number of false positives, but resulted in increasing numbers of false negatives. Even if 1 mm. or more of ST depression was required, there were 8 per cent false positives and 43 per cent false negatives. There were no false positives only when the ST segment was depressed 2 mm. or more.

Although an ischemic type of ST depression may be more significant for angina pectoris than the J type, in our series ischemic ST depressions also occurred more frequently than the J type in false-positive tests in nonanginal patients.

The new criteria of Master and Rosenfeld were not more satisfactory than the previous criteria recommended.

There are relatively few cases in which an objective two-step test is necessary to aid in the differentiation of anginal and nonanginal pain, since an unequivocal diagnosis of angina pectoris or nonanginal pain was made in 86 per cent of cases independently by at least two observers, on the basis of a single interview, and since this percentage could undoubtedly have been increased by further interviews concerning the effect of effort and of nitroglycerin.

Insofar as confirmation of a clinical diagnosis of angina pectoris by an objective exercise test is desirable, an ST-segment depression of at least 1 mm. usually offers such confirmation. However, this degree of ST-segment depression is often absent in unequivocal cases of angina pectoris and conversely may be occasionally present in patients with nonanginal pain.
Changes in Pulmonary Vascular Resistance in Infants and Children with Left-to-Right Intracardiac Shunts
Authors: AULD P. A. M. , JOHNSON A. L. , GIBBONS J. E. , MCGREGOR M.
Published: June 2012

The hemodynamic data of seventeen patients with left-to-right intracardiac shunts and pulmonary hypertension have been reviewed. A considerable rise in pulmonary vascular resistance was observed in 12 of these patients between the time of the first and second catheterizations. The results suggest that the possibility of progressive elevation of pulmonary vascular resistance with the passage of time should be a serious consideration in the selection of optimum age for operation in patients with left-to-right intracardiac shunts.
Accessory Valvular Tissue Causing Subpulmonary Stenosis in Corrected Transposition of Great Vessels
Authors: LEVY MORRIS J. , LILLEHEI C. WALTON , ELLIOTT LARRY P. , CAREY LEWIS S. , ADAMS PAUL , EDWARDS JESSE E.
Published: June 2012

This study reveals three cases of corrected transposition (one with total situs inversus) where an accessory flap or umbrella-like formation of the venous atrioventricular valve presented into the outflow tract of the venous ventricle causing severe subpulmonary stenosis.

In one case the ventricular septum was intact, while in each of the other two, a ventricular septal defect lay below the obstruction. The latter combination effected a right-to-left shunt at ventricular level.

These cases are important because they portray anatomic details of a condition which, although uncommon, is potentially curable. Clinical identification of the subpulmonary stenosis appears best to be accomplished by selective angiocardiography at the level of the venous ventricle.
Reflected Ultrasound in the Assessment of Mitral Valve Disease
Authors: JOYNER CLAUDE R. , REID JOHN M. , BOND JAMES P.
Published: June 2012

An ultrasound beam directed into a medium of uniform acoustical impedance will travel in a straight line, but a portion of the waves will be reflected at the interface of a medium of different acoustical impedance. A time-distance curve of motion has been obtained from the heart by recording the echoes returned to a send-receive ultrasound transducer applied in the third, fourth, or fifth left interspace. A characteristic curve having two anterior peaks during each cardiac cycle was obtained in the 25 normal patients studied. One peak follows the P wave of the electrocardiogram and is not seen in atrial fibrillation. The other peak of motion toward the anterior chest is followed by rapid regression posteriorly during ventricular diastole. The velocity of the motion was 85 to 160 mm./sec. in normal subjects. In contrast, the records from 90 patients with mitral stenosis demonstrated a distinctive, abnormal pattern having a plateautype configuration with a velocity of posterior motion of only 2 to 35 mm./sec. The configuration of the curve changed toward normal after successful mitral valvulotomy but none of the 35 patients who were studied before and after surgery has developed a calculated postoperative velocity exceeding 70 mm./sec.

Twelve patients with "pure" mitral regurgitation have had records similar to the normal, with velocities in or above the normal range. None of the 135 other patients studied, representing a variety of conditions, demonstrated a curve of the type found in mitral stenosis.
A Vascular Abnormality in Hypertension
Authors: CONWAY JAMES
Published: June 2012

Forearm blood flow measurements have been made at rest and after 8 to 10 minutes arterial occlusion in 50 normal and 131 untreated hypertensive subjects. The latter group comprised 91 with essential hypertension; 11 with chronic renal disease (nephritis or pyelonephritis); 21 with renovascular disease; and eight with primary aldosteronism.

The resting blood flow increased with the rising pressure in patients with mild hypertension but there was a significant increase in the resting resistance in the more severe cases. The average minimal resistance obtained during reactive hyperemia was greater in hypertensive (3.1 SE 1.0 units) than in normal subjects (2.0 SE 0.07 units). This abnormality was related to the level of blood pressure but not to the duration of the disease.

Patients with renovascular disease or aldosteronism presented the same vascular fault as the more common causes of hypertension.

Evidence is presented to show that the reactive hyperemia produced maximal dilatation of the forearm vasculature, and acute elevation in pressure in normotensive or acute depression of pressure in hypertensive subjects did not influence the level of resistance achieved by reactive hyperemia.

It is concluded that the blood vessels themselves are abnormal in hypertension and that this abnormality may not be related to the activity of vascular smooth muscle.
Effect of Exercise on the Pulmonary Blood Volume in Patients with Acquired Heart Disease
Authors: SCHREINER BERNARD F. , MURPHY GERALD W. , GLICK GERALD , YU PAUL N.
Published: June 2012

The effect of supine exercise on the pulmonary blood volume was studied in 14 patients with valvular heart disease and in one patient with cardiomyopathy. Statistically significant increases occurred in the pulmonary blood volume (88.6 ± S.E. 20.9 ml./M.
2
) and in the central blood volume (121.9 ± S.E. 29.2 ml./M.
2
), whereas left atrial to brachial arterial volume remained unchanged. These results support the concept that, with exercise, increases in central blood volume reflect increases in pulmonary blood volume in patients with acquired heart disease. The increase in pulmonary blood volume and in pulmonary distending pressure suggests a passive expansion of the pulmonary vascular bed with exercise.
Pulmonary Stenosis
Authors: SCHERLIS LEONARD , KOENKER ROLF J. , LEE YU-CHEN
Published: June 2012

The electrocardiographic, vectorcardiographic, and right heart catheterization data of 100 patients with isolated or complicated pulmonary stenosis were analyzed.

All but two patients had normal sinus rhythm. One patient, age 62, had atrial fibrillation; the other, age 8, had the Wolff-Parkin-son-White syndrome.

In isolated pulmonary stenosis, P-wave enlargement was far more frequently seen in those patients with right ventricular systolic pressures above 100 mm. Hg as compared to those with pressures less than 100 mm. Hg. This relationship was not observed in patients with complicated pulmonary stenosis.

The incidence of rsR' in V
1
, QRS widening, and the vectorcardiographic evidence of conduction delay was significantly lower in pulmonary stenosis, isolated or complicated, when compared to atrial septal defects alone. There was one instance of terminal conduction delay of the right bundle-branch block type and one diffuse slowing of the QRS sÊ loop in the present series.

The correlation between the amplitude of the R wave in V
1
and right ventricular systolic pressure was better in the group of isolated pulmonary stenosis as compared to the groups complicated by interatrial communications or ventricular septal defects.

The average right ventricular systolic pressures in patients with type 3 right ventricular hypertrophy was significantly higher than those with either type 1 or type 2 right ventricular hypertrophy on the basis of vectorcardiographic criteria discussed. In the presence of pulmonary stenosis, the electrocardiographic and vectorcardiographic evidence of left ventricular hypertrophy or combined ventricular hypertrophy suggests coexisting lesions such as ventricular septal defect with left-to-right shunts. However, it was not possible to differentiate between isolated pulmonary stenosis and pulmonary stenosis complicated by interatrial communication by either electrocardiograms or vectorcardiograms.

The vectorcardiographic features of combined ventricular hypertrophy are discussed.
Digital Hemodynamics in the Normotensive and Hypertensive States
Authors: CALIVA FRANCIS S. , NAPODANO RUDOLPH J. , LYONS RICHARD H.
Published: June 2012

By use of the technic of rheoplethysmography, it has been demonstrated that the small veins and venules participate in the over-all increase in peripheral resistance in hypertension.

An arbitrary grading of the degree of venomotor tone in hypertension has been established.
Further Observations on the Natural History of Isolated Ventricular Septal Defects in Infancy and Childhood
Authors: ARCILLA RENE A. , AGUSTSSON MAGNUS H. , BICOFF J. PEDRO , LYNFIELD JOSHUA , WEINBERG MILTON , FELL EGBERT H. , GASUL BENJAMIN M.
Published: June 2012

Serial cardiac catheterization has been performed in 75 patients with isolated ventricular septal defect. At the time of the first cardiac catheterization, 39 were under 1 year of age, 19 were between 1 to 3 years, 14 between 3 to 10 years, and three over 10 years. In 68 patients the second catheterization was performed 1 to 7 years after the first, and in seven patients a third cardiac catheterization was performed 2 to 5 years after the second.

Normal pulmonary artery pressure was observed at the initial study in 25 patients. Of these, only one revealed a slight rise in pulmonary artery systolic pressure by 19 mm. Hg; the rest revealed no significant hemodynamic changes.

Mild pulmonary hypertension (31 to 59 mm. Hg systolic pressure) was noted in 28 patients at first catheterization, at which time moderate or severe pulmonary hypertension (60 mm. Hg or more systolic pressure) was present in 22 patients. In 33 of these 50 cases, the initial investigation was done during infancy and not later than the second year. In three fourths of the cases with mild pulmonary hypertension, and in two thirds of those with moderate or severe hypertension studied at this very early age, a significant drop in pulmonary pressure and flow was observed at the subsequent catheterization. This was interpreted to indicate most likely relative reduction of the functional size of the defect during early childhood. In eight patients hemodynamic and angiocardiographic evidence of the ventricular septal defect disappeared, indicating probable functional closure.

Progressive pulmonary vascular obstruction was observed in six patients, one of whom already had Eisenmenger's complex at the initial examination. All but one, an 11-month-old infant, had significantly elevated pulmonary vascular resistance already present during the first cardiac catheterization. In seven patients with similar findings at the initial examination, striking reduction in pulmonary vascular resistance was observed. The progressive pulmonary vascular obstruction is interpreted to indicate failure of the pulmonary vascular bed to undergo maturation, whereas the diminution in pulmonary resistance observed in the other group is interpreted to indicate delayed onset of pulmonary vascular maturation.

The therapeutic significance of these findings is discussed.
Recent Views on Mechanisms for Lowering Sympathetic Tone
Authors: BRODIE BERNARD B.
Published: June 2012

A picture is gradually unfolding of the molecular structures at nerve endings which synthesize and store norepinephrine and release the amine onto sympathetic receptors. Norepinephrine is formed continuously regardless of sympathetic tone and is stored inside a lipoid membrane. The amine is present in two pools—a reserve pool in granules in equilibrium with a mobile pool which is maintained against a concentration gradient by active transport. MAO controls the amount of norepinephrine in the nerve ending so that at the steady-state level the amine does not freely diffuse onto receptor sites. In the absence of sympathetic tone, norepinephrine can leave the storage compartments by simple diffusion through the lipoid membrane onto MAO. After nerve stimulation the amine is released directly onto the receptor sites and reaches the blood stream in the form of bases.

This model for the transducer helps to explain the action of a number of drugs. Amphetamine increases blood pressure by releasing a small amount of norepinephrine at peripheral sympathetic nerve endings. Reserpine lowers blood pressure by inhibiting the norepinephrine pump which maintains the amine in the mobile pool; as a result the peripheral stores of amine are depleted by an uncompensated diffusion of the amine onto MAO.

Bretylium and a number of benzyl derivatives of guanidine lower blood pressure by preventing nerve impulses from releasing norepinephrine at sympathetic nerve endings. Guanethidine and a number of phenylethyl guanidine derivatives cause lowering of arterial pressure by depleting the peripheral stores of norepinephrine perhaps through a persistent activation of the physiologic release mechanism. Alpha-methyldopa, α-methyl-metatyrosine, and metaraminol may act in a similar way.

Finally, considerable evidence suggests that MAO inhibitors lower blood pressure by exerting a bretylium-like action. They not only prevent guanethidine from releasing norepinephrine but like bretylium they appear to prevent nerve impulses from releasing norepinephrine onto receptors.
Rupture of the Coronary Sinus with Hemopericardium
Authors: HABERMANN J. H. , HOWARD M. L. , JOHNSON E. S.
Published: June 2012

Sudden death is reported in a previously healthy 52-year-old man resulting from a rare complication of a coronary arteriovenous fistula. It is believed that the primary defect was congenital and that the sequence of events was dilatation and thrombosis of the coronary sinus, necrosis of the sinus wall, perforation, and fatal tamponade.
Intermittent Claudication Secondary to Idiopathic Fibrous Retroperitonitis
Authors: LARSON RICHARD E. , ROSS JAMES V.
Published: June 2012

In the case of idiopathic fibrous retroperitonitis presented, the only symptoms were those of arterial insufficiency of the lower limbs and testicular and inguinal pain of uncertain origin. Relief of claudication and return of normal pulsations were achieved after surgical lysis of the common iliac arteries and the terminal segment of the aorta. Numerous reports in the literature indicate that idiopathic fibrous retroperitonitis is not rare but retroperitoneal arterial obstruction by the fibrous plaque is apparently unusual, and intermittent claudication without urinary symptoms is unique.

Idiopathic fibrous retroperitonitis, therefore, should be included in the differential diagnosis of the causes of intermittent claudication. Although the aortogram may not permit differentiation of arteriosclerosis obliterans from external compression of the aorta by this fibrosing process, the excretory urogram should be helpful in making or excluding the diagnosis. Treatment is primarily surgical with thorough excision of the fibrous mass and with ureteral transplantation; vascular resection or bypass grafting is not necessary. Advisability of postoperative roentgen and adrenal corticoid therapy is not clearly established.
Effects of Beta Adrenergic Blockade on the Circulation, with Particular Reference to Observations in Patients with Hypertrophic Subaortic Stenosis
Authors: HARRISON DONALD C. , BRAUNWALD EUGENE , GLICK GERALD , MASON DEAN T. , CHIDSEY CHARLES A. , ROSS JOHN
Published: June 2012

The circulatory effects of blocking the beta adrenergic receptors with Nethalide were studied in 10 patients with hypertrophic subaortic stenosis and in five postoperative subjects undergoing right heart catheterization. In the resting state, the heart rate and the rate of pressure development in the right ventricle diminished slightly, but cardiac index was not altered by the administration of Nethalide. These observations suggest that tonic sympathetic activity is not of major importance in basal subjects in the supine position. Nethalide attenuated the increase in heart rate and right ventricular dp/dt associated with exercise, and abolished the response of these two variables to the administration of isoproterenol. In the patients with hypertrophic subaortic stenosis Nethalide had little effect on the severity of the obstruction at rest, but reduced the intensification of the obstruction produced by exercise or isoproterenol. The possible clinical benefits of blocking the beta adrenergic receptors in these patients were discussed.
Hemodynamic and Ventilatory Effects of Exercise in the Upright Position in Patients with Left-to-Right Shunts
Authors: STEPHENS NEWMAN L. , SHAFTER HAROLD A. , BLISS HARRY A.
Published: June 2012

Nine patients having ventricular septal defect or patent ductus arteriosus performed bicycle exercise of moderate intensity in the upright position while oxygen consumption and pulmonary and systemic blood flows and pressures were being measured. Resting pulmonary vascular resistance (PVR) was normal in five patients and elevated in four.

Right-to-left shunt became apparent or increased during exercise in patients with elevated PVR. The rise of pulmonary "wedge" pressure and of right atrial pressure during exercise was not related to the resting PVR. Both ventilation and pulmonary artery pressure increased more rapidly during exercise in patients with high PVR than in the normal PVR group.

Left atrial blood remained fully saturated during exertion in three patients with high PVR and arterial oxygen unsaturation.
Treatment of Congenital and Acquired Heart Block with an Implantable Pacemaker
Authors: TABER RODMAN E. , ESTOYE LUDOVICO R. , GREEN EDWARD R. , GAHAGAN THOMAS
Published: June 2012

The Chardack-Greatbatch implantable pacemaker has proved a worthwhile device for the management of both congenital and acquired heart block. The procedure used for implantation in 38 patients is described. The most frequent indication for use of the pacemaker is syncope due to heart block. Progressive cardiac enlargement was also an indication for pacemaker implantation in two of four children with congenital heart block. The pacemaker has also been useful in the management of surgically induced heart block and coexisting heart block that accompanies intracardiac lesions, such as aortic stenosis, which require open-heart surgery.

Pacemaker failure due to electrode breakage occurred in two patients. In both instances, a replacement unit was successfully used. Three of the 38 patients have subsequently died from causes unrelated to pacemaking while one death resulted from pacemaker failure 12 months after implantation. The remaining 34 patients have remained free from cardiac symptoms during observation periods of 2 to 24 months.
Mitral Valve Disease Complicated by Left-to-Right Shunt at Atrial Level
Authors: MARSHALL ROBERT J. , WARDEN HERBERT E.
Published: June 2012

The clinical features and the changes in hemodynamics are described before and after operation in two patients with mitral valve disease associated with left-to-right shunt at atrial level.

The first patient had severe rheumatic mitral stenosis, which masked the associated moderate shunt. Since the interatrial communication was small, there was a moderate gradient in pressure between the two atria. Thus, the finding of an elevated left atrial or pulmonary artery wedge pressure in a patient with mitral stenosis and an increase in the saturation of blood at atrial level does not eliminate the possibility of a small interatrial communication.

The second patient had severe mitral regurgitation due to a structurally abnormal valve with ruptured chordae tendineae, and had also functional pulmonary and tricuspid valve regurgitation. These lesions also masked the associated large left-to-right shunt. Electrocardiographic and angiocardiographic criteria were used to exclude the possibilities of persistent atrioventricular canal defect and of left ventricle-right atrium shunt.

After operation, cardiac catheterization demonstrated a return of the hemodynamic changes toward normal in both patients. There was also a striking clinical improvement.

In both, the interatrial communication was situated in the fossa ovalis. It appeared to be a foramen ovale that had become patent due to stretching of the walls of the left atrium, rather than a true atrial septal defect. Although left-to-right shunting may occur through a patent foramen ovale in infants with mitral or aortic valve atresia, we are unaware of previous hemodynamic or surgical evidence of a similar phenomenon developing as a consequence of severe mitral valve disease in adults.
Vectorcardiographic Residua of Inferior Infarction
Authors: HOFFMAN IRWIN , TAYMOR ROBERT C. , GOOTNICK ABRAHAM
Published: June 2012

Seventy-eight patients with well-documented inferior infarction were studied by the Frank vectorcardiographic technic.

The commonest residual was superior and leftward orientation of the early forces that moved clockwise in the frontal projection.

Quantitative data on the duration, magnitude, and leftward sweep of these forces are presented.

In 52 cases, the entire frontal loop was clockwise. When sagittal loop reversal, partial or total, ocurred in this group, a high correlation with associated anterior infarction or left ventricular enlargement was noted.

In 24 patients, the returning frontal limb was deformed due to upward bowing. When anterior forces were well preserved in the presence of this deformity, a characteristic "pollywog" shape in the sagittal loop resulted.

Conduction defects were twice as common in the cases with mid-loop frontal deformity as in the cases without such defects.

Anterior forces of prominent voltage and prolonged duration were noted in 19 cases. Quantitative data on these cases, presumably reflecting associated posterior infarction, are presented.

The vectorcardiographic residua of inferior infarction may be classified according to rotational characteristics of the frontal and sagital loops. Classification may be of value in providing clues to associated anterior disease, left ventricular enlargement, and conduction defect.
Spatial Vector Electrocardiography
Authors: GRANT ROBERT P. , ESTES E. HARVEY , DOYLE JOSEPH T.
Published: June 2012

The application of a spatial vector method of interpretation to the S-T and T deflections in the conventional electrocardiogram is described, and the vector abnormalities responsible for the more commonly encountered deformities are discussed. In addition, the isolated T-negativity syndrome is described, a rare type of precordial T-wave inversion which may be encountered in normal subjects and is often indistinguishable from the ST-T deformity of recent myocardial infarction. The spatial vector method of interpretation is found to provide a simple yet rational basis for the interpretation of these often bizarre wave forms.
Large Thymic Tumor Simulating Pericardial Effusion
Authors: BERNSTEIN ARTHUR , KLOSK EMANUEL , SIMON FRANKLIN , BRODKIN HENRY A.
Published: June 2012

A case of a 20 year old man with a large thymic tumor simulating a pericardial effusion is reported. This tumor, by its position, size and "fluidity," mimicked a pericardial effusion so well that it was only at surgery that a definitive diagnosis could be made. Upon removal of the mass recovery has been complete.
Advanced Disturbances of the Cardiac Mechanism in Potassium Intoxication in Man
Authors: LEVINE HAROLD D. , MERRILL JOHN P. , SOMERVILLE WALTER
Published: June 2012

The use of the artificial kidney at the Peter Bent Brigham Hospital in the treatment of acute renal shutdown has afforded a unique and extensive opportunity to study the disturbances of rhythm and conduction occurring in potassium intoxication. In this theoretic, and at times frankly speculative, paper the authors present evidence which suggests the applicability to man of Wiggers' views based upon animal experimentation, namely that the ectopic rhythms developing in this condition arise "by default" (escape mechanisms) rather than "by usurpation" (increased excitability) and that potassium exerts its early and preponderant effect upon the subendocardial layers of the human ventricle.
Electrocardiographic Changes after Glucose Ingestion
Authors: OSTRANDER LEON D. , WEINSTEIN BELSON JACK
Published: June 2012

In order to determine the effect of glucose ingestion on the electrocardiogram, 23 men with coronary heart disease and 30 without known heart disease had electrocardiograms in the fasting state and serial tracings at 30-minute intervals after the administration of 100 Gm. of oral glucose. In both groups the mean changes after glucose ingestion were slight ST-segment depression, a moderate decrease in T-wave amplitude, and a slight increase in heart rate, although individual variability was great. When the electrocardiograms were classified by a uniform coding system, new ST-segment or T-wave classifications were recorded for eight of 23 subjects with coronary heart disease and three of 30 men without known heart disease.

Since ST-segment and T-wave changes regularly follow glucose ingestion and are sometimes of sufficient degree to suggest heart disease in apparently normal individuals, electrocardiograms recorded within several hours after glucose administration must be interpreted with caution. Because of the uncertain significance of postprandial ST-segment and T-wave changes, electrocardiograms after glucose ingestion do not appear to be a very useful method for the detection of occult heart disease. Glucose ingestion should be avoided before routine clinical tracings.
Congenital Aneurysm of the Membranous Portion of the Ventricular Septum
Authors: CAMPBELL RICHARD W. , STEINMETZ E. F. , HELMEN CHARLES H.
Published: June 2012

A case of an isolated aneurysm of the ventricular septum with a loud holosystolic murmur at the fourth left interspace is presented. The origin of the murmur is ascribed to the aneurysm of the ventricular septum.
Some General Considerations on Vascular Reactivity
Authors: Hoobler Sibley W. , Rodbard Simon , HOLLANDER WILLIAM , YAGI SHIGERU , KRAMSCH DIETER M.
Published: June 2012

Norepinephrine and epinephrine in pharmacological doses significantly inhibited the synthesis of acid mucopolysaccharides and lipids in incubated dog arterial tissue, whereas angiotensin had no detectable effect on these metabolic functions. Although these findings suggested different metabolic effects of the catecholamines and angiotensin, differences in rates of inactivation of these agents could not be excluded as a cause for their different actions. The inactivation of angiotensin by incubated dog arterial tissue appeared to be over a hundred times more rapid than that of the catecholamines. The differences in the in vitro and the in vivo inactivation of the catecholamines are most likely related to the inability of the denervated tissue to bind, and hence inactivate, the amines. Tissue binding, rather than enzyme degradation of catecholamines, appears to be the major mechanism responsible for the rapid inactivation of the pharmacological activity of the catecholamines. It is suggested that the changes in the reactivity of the blood pressure to cold, norepinephrine, chlorothiazide, and reserpine are related to the binding of catecholamines in the tissues. It is also postulated that one of the basic disturbances in essential hypertension might be an accumulation of pharmacologically active norepinephrine in the arterioles due to insufficient binding of the amine in the tissues.
Effect of Bilateral Nephrectomy and Kidney Transplantation on Hypertension in Man
Authors: KOLFF WILLIEM J. , NAKAMOTO SATORU , POUTASSE EUGENE F. , STRAFFON RALPH A. , FIGUEROA JULIO E.
Published: June 2012

In conclusion, we consider that renal hypertension may have two components: a renal component and a renoprival component (fig. 6). Bilateral nephrectomy abolishes the renal component and leaves a renoprival hypertension that is sensitive to water and salt. Implantation of a kidney may cure the renoprival hypertension. Rejection of the graft may then be followed by a return of renal hypertension. Since the technique of transplantation of kidneys taken from cadavers is improving steadily, repeated nephrectomies and a second transplant become possible.
Similarities Between Clinical Toxemia of Pregnancy and Experimental Hypertension
Authors: TOBIAN LOUIS
Published: June 2012

Many of the features of human toxemia of pregnancy can also be found in certain types of experimental hypertension. The similarity is especially close with regard to desoxycorti-costerone hypertension in rats. A working hypothesis concerning toxemia is presented which involves the rate of synthesis of placental steroids, their rate of degradation, and the degree of antihypertensive capacity.
The Case for Anticoagulant Therapy
Authors: WRIGHT IRVING S.
Published: June 2012

In summary, the total world evidence suggests that in the absence of compelling contraindications and with the availability of satisfactory laboratory and clinical facilities, patients suffering with acute myocardial infarction should receive adequate anticoagulant therapy during the first month, and that the risk of reinfarction and death is reduced if this is continued for 1 to 2 years after the first month. More long-term studies should be conducted to evaluate this treatment for succeeding years. This form of therapy presents certain difficulties that must be weighed against the possible gains in deciding whether or not to continue it.
Effect of Chronically Increased Ventricular Pressure on Electrical Forces of the Heart
Authors: HUGENHOLTZ PAUL G. , GAMBOA RAUL
Published: June 2012

Hemodynamic measurements during left and right heart catheterization in 90 patients with aortic or pulmonic stenosis have been correlated with selected vectorcardiographic parameters obtained by the Frank vectorcardiogram.

Evidence has been presented that increased left ventricular peak pressure (r=0.85) or pressure time (r=0.78) leads to augmented maximum spatial voltages. The coefficients for similar correlations on the right side of the heart were 0.87, respectively 0.82. When a sum of selected spatial vectors was used the correlation coefficient with left ventricular peak pressure rose to 0.90 (with controls r=0.93) and with right ventricular peak pressure to 0.89, while at the same time the standard error became less. Less significant correlations existed with the log of the valve area (r=–0.69 for the aortic valve and r=–0.66 for the pulmonary valve) and stroke work (r= 0.24 for left and r=0.32 for right ventricular work).

These findings provide a further link between the morphology and the physiology of the ventricle producing wall tension and intracavitary pressure. The demonstration of no change in MSV over years of growth, while the heart increases from 20 grams to its mature weight of 300 grams and the remarkable linear increase in MSV once elevated resting pressure is produced, shows that the vectorcardiogram is capable of reflecting accurately the average peak pressure and pressure time delivered by either ventricle. Furthermore, the less significant relationship with stroke work or valve area, in the face of the good correlation with pressure time per minute and peak pressure, in particular, indicates that chronically increased ventricular pressure in obstructive lesions is the chief factor altering MSV. On the basis of Linzbach's histologic studies, it appears that the essential measurement made by the MSV or the SMSV is the number of cells constituting the actively contracting myocardial syncytium required for the maintenance of average resting ventricular systolic pressure.
The Quantitative Anatomy of Cyanotic Tetralogy of Fallot
Authors: LEV MAURICE , RIMOLDI HORACIO J. A. , ROWLATT URSULA F.
Published: June 2012

A quantitative analysis was made of hearts with tetralogy of Fallot without operative procedures, with pulmonary atresia, with total repair, and with old Potts anastomosis and total repair. Useful data thus obtained were as follows:

In simple tetralogy the left ventricle has a tendency to volume atrophy. The tricuspid orifice has a tendency to be smaller than normal.

In tetralogy with pulmonary atresia, the aortic orifice has a tendency to be larger, and the mitral orifice smaller than in ordinary tetralogy.

In tetralogy after total repair, the heart is increased in weight 24 to 48 hours later probably related to manipulation of the right ventricle. The tricuspid and aortic orifices have a tendency to be smaller than previously, probably related to the technic of closure of the ventricular septal defect. This is not the case where an aorticopulmonary anastomosis has been previously done before total repair.
Nitrogenous Compounds in Hemodialysate
Authors: LUBASH GLENN D. , STENZEL KURT H. , RUBIN ALBERT L.
Published: June 2012

Correlation of clinical and chemical changes in patients with uremia has not been possible for substances other than urea and electrolytes. Since clinical improvement is frequently seen following hemodialysis, examination of the dialysate for substances of possible importance seemed warranted. With use of the Kiil artificial kidney, small volumes of dialysate have been obtained and found suitable for analytical studies. Amino acid analyses performed after salt removal revealed a preponderance of acidic amino acids and 35 to 38 unknown ninhydrin reactive peaks. Following acid hydrolysis, the unknown peaks decreased in height and known amino acids increased, indicating a degradation of peptides or conjugated amino acids. Elution from the internal volume of Sephadex G-25 columns suggested molecular weights of less than 4000. Confirmatory evidence of low molecular weights was obtained in vitro by estimation of ninhydrin and Folin-Lowry phenol reactive materials remaining in the dialysant compared to glucose and urea. These results suggested that besides free amino acids, the nitrogenous compounds in the dialysate include conjugated amino acids or very small peptides. Of additional interest in one patient was the decrease in removal of some amino acids and other nitrogenous materials from the first to the eighth clinical dialysis, suggesting a relationship to progressive malnutrition observed in this case.
Atrial Heart Sounds in Atrial Fibrillation and Fluttter
Authors: NEPORENT LEWIS M.
Published: June 2012

Audible atrial contractions were recorded in a case of rheumatic heart disease during atrial fibrillation and the transition stage to atrial flutter. With coarse atrial fibrillation these correlated only roughly with the electrocardiogram, and appeared to have a regularity not always apparent on the electrocardiogram.

In atrial flutter, the atrial contraction sounds were synchronous with the "f" waves. The intensity, quality, and occurrence of the atrial sounds during ventricular systole suggest an extracardiac origin.
Coronary Artery Anomalies
Authors: BLAKE HU A. , MANION WILLIAM C. , MATTINGLY THOMAS W. , BAROLDI GIORGIO
Published: June 2012

Twenty-two selected anomalies of the coronary arteries are related to cases previously reported in the literature. These are presented with simplified drawings and photographs in an attempt to provide a workable understanding of the practical problems such create for both the internist and surgeon.