bluuebunny/crossref_metadata_2025_split huggingface dataset:
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.
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.
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.
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.
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.
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.
Hemodynamic Patterns in Essential Hypertension
Authors: FINKIELMAN SAMUEL , WORCEL MANUEL , AGREST ALBERTO 
Published: June 2012

Hemodynamic studies, including cardiac output, arterial blood pressure, run-off index, flow cessation pressure, and blood volume, were performed in 20 normotensive control subjects, 17 labile hypertensive patients and 20 patients with fixed hypertension, 10 of them with a mild elevation of the diastolic pressure and 10 classified as severe because of a diastolic blood pressure above 110 mm. Hg.
In labile hypertension cardiac output was elevated, whereas blood volume, peripheral resistance, run-off index and flow cessation pressure were normal when blood pressure was high. This hemodynamic pattern was interpreted as due to an enhanced myocardial contractile energy or a restriction of the capacity vascular bed.
In mild fixed hypertension total peripheral resistance and flow cessation pressure were uniformly increased, but cardiac output and run-off index were normal. This pattern may be explained by the influence of flow autoregulation and the barostatic mechanism.
In severe fixed hypertension blood volume, cardiac output, and peripheral resistance were found to be high. Renal ischemia and secondary hyperaldosteronism may determine the development of this last stage of hypertension.
Severe Mitral Regurgitation Secondary to Ruptured Chordae Tendineae
Authors: SANDERS CHARLES A. , SCANNELL J. GORDON , HARTHORNE J. WARREN , AUSTEN W. GERALD 
Published: June 2012

Fifteen cases of severe mitral regurgitation secondary to ruptured chordae tendineae have been reviewed, eight of whom underwent open-heart surgery to correct their lesions. Three patients are living at this time with two being markedly improved. Cardiac catheterization was performed in six prior to surgery.
Progressive deterioration within the year following the onset of difficulty or sudden worsening of previous cardiac symptoms characterized the usual clinical course. The apical systolic murmur, always loud, was conspicuously harsh and radiated to the base of the heart, simulating aortic stenosis when the mural cusp was ruptured. Although strongly suggesting the diagnosis, the sudden onset of an apical systolic murmur could be documented in only three instances. The presence of a small left atrium radiographically with tall left atrial "v" waves and marked reflux of contrast material into a paradoxically pulsating left atrium also pointed to the correct diagnosis.
Various technics of surgical repair and problems influencing survival of patients in the present series are discussed.
Ventricular Fusion Beats during Electric Stimulation in Man
Authors: LINENTHAL ARTHUR J. , ZOLL PAUL M. 
Published: June 2012

Quantitative studies of ventricular fusion beats were made in 40 patients with Stokes- Adams disease after implantation of electric pacemakers in the left ventricle. The two fusing complexes came from an electric pacemaker and either a second electric pacemaker or a conducted sinoatrial beat. The limit of fusion, that is the maximal time between two fusing complexes, gives a measure of the conduction time and velocity between the two points of initial ventricular depolarization.
Conduction between two electric pacemakers and in retrograde direction from an electric pacemaker to the point of entry of a conducted beat was by way of ordinary myocardium; its velocity was about 1 meter per second. Conduction in antegrade direction, on the other hand, was by way of specialized Purkinje tissue; and its velocity was 4.5 to 9 times faster.
Variations in conduction times with bundle-branch block support this interpretation: retrograde conduction time did not change; antegrade conduction time was prolonged in left but was usually unchanged in right bundle-branch block.
The morphologic similarities of fusion beats in our patients to the features of anomalous AV excitation add strong evidence in man to the previous analogous experimental observations that the WPW complex is a fusion beat. Furthermore, quantitative comparison of WPW and our fusion beats supports the theory that the anomalous excitation in the WPW phenomenon, like the peripherally located artificial stimulus, enters the ventricle peripherally, by way of an accessory AV pathway.
Calculation of Cardiac Output from Indicator-Dilution Curves in the Presence of Mitral Regurgitation
Authors: RAHIMTOOLA SHAHBUDIN H. , SWAN H. J. C. 
Published: June 2012

Cardiac output was determined by the indicator-dilution technic with injection of indicator into the ascending aorta, left ventricle, and pulmonary artery in 13 cases of mitral incompetence and in 15 control cases (normal or mild valvular obstruction). The ascending aortic dye curve is not involved in mitral incompetence in its primary circulation and was used for comparison.
In normal subjects, there is no significant difference between the cardiac output obtained by injection of indicator into the ascending aorta and the left ventricle.
The cardiac output obtained from indicator-dilution curves affected by mitral regurgitation in its primary circulation is underestimated by approximately 20 per cent.
The effects of the coronary recirculated indicator particles on the disappearance slope would best explain the discrepancy. Even in the normal circulation, the inclusion of the coronary recirculated particles leads to a small underestimation of the cardiac output when the indicator is injected into the pulmonary artery.
Hemodynamic Consequences of the Injection of Radiopaque Material
Authors: FRIESINGER G. C. , SCHAFFER JOCHEN , CRILEY J. MICHAEL , GAERTNER ROBERT A. , ROSS RICHARD S. 
Published: June 2012

The hemodynamic changes resulting from injection of radiopaque material into the left heart in a series of patients undergong cineangiographic studies have been reported. The hypertonicity of radiopaque materials appears to be responsible for much of the observed reaction. The mechanism whereby hypertonic solutions produce the observed physiologic changes remains unknown.
Changes observed in patients could be reproduced in experimental animals. The combined experimental and clinical data show that left atrial pressure increases, left atrial pulse contour alters, stroke output increases, heart rate is much unchanged, peripheral artery pressure falls, hematocrit level falls, and myocardial contractile force decreases mildly and transiently.
The difference between the physiologic effects of injecting hypertonic media into the right and left sides of the circulation is discussed.
Because the pressure changes are easy to monitor and parallel the other features of the hemodynamic reaction, it is good to wait until pressures have returned to the pre-angiographic level before proceeding with the injection of more radiopaque material. This usually requires 15 minutes.