bluuebunny/crossref_metadata_2025 huggingface dataset:
Atrial Septal Defect in the Older Patient
Authors: SAKSENA FRANKLIN B. , ALDRIDGE HAROLD E.
Published: June 2012

Twenty-four patients over 35 years of age with a secundum atrial septal defect (ASD) had a clinical and hemodynamic assessment prior to surgical closure and a follow-up assessment an average of 6 years afterward. All were initially in functional class III or IV. Twenty-three patients had a moderate to large left-to-right shunt. Five had elevated pulmonary vascular resistance (PVR); all had moderate to severe pulmonary hypertension. Left ventricular dysfunction (LVD) was found in 17.

Following surgical closure, 22 patients showed sustained clinical improvement and were in class I or II. The mean pulmonary artery pressure fell to normal or mildly elevated values in 21. The PVR was now elevated in 14 patients, suggesting continued progression of obliterative pulmonary vascular disease. Three had small residual shunts. LVD, however, persisted after operation, which may reflect underlying myocardial pathology unrelated to the ASD.

Operative closure of ASD, therefore, is recommended for disabled patients over 35, even if they have moderate pulmonary hypertension or congestive heart failure.
Percutaneous Heart Catheterization in Infants and Children
Authors: TAKAHASHI MASATO , PETRY EUGENE L. , LURIE PAUL R. , KIRKPATRICK STANLEY E. , STANTON ROBERT E.
Published: June 2012

This report describes in detail the materials and methods used in the authors' laboratory for percutaneous insertion of catheters and for manipulation of catheters with guide wires in infants and children. A simple thin-walled spinal needle is used to enter femoral vessels initially. Catheter insertion is effected thereafter with the sequential uses of a guide wire, a dilator, and an end-hole catheter. Insertion of two or three catheters into a single vessel may be accomplished. In infants weighing less than 20 pounds, dilation of the vascular puncture wound may be accomplished in stages. Guide wires of different configurations are used for catheter manipulation into various cardiac structures including some which are relatively inaccessible. Guide wires are also used for catheter exchange. Angiograms of high quality may be obtained safely.
Permanent Pacing of the Left Atrium for Treatment of WPW Tachycardia
Authors: PRESTON T. A. , KIRSH MARVIN M.
Published: June 2012

A patient with WPW paroxysmal tachycardia was treated with a permanent artificial pacemaker, with the electrodes attached to the left atrium. The pacemaker is turned off at all times except when the patient activates it by holding a magnet over the implanted power unit. Random atrial pacing at a rate of 108/min has always terminated the tachycardia within 1 min, and usually within 10 sec.

Left atrial pacing produced WPW type A QRS complexes, whereas regular sinus rhythm and right atrial pacing resulted in more normal QRS complexes. The distinct difference in the QRS complexes suggests preferential conduction through an abnormal pathway during left atrial pacing.
Abnormal Left Ventricular Contraction in Patients with Mitral Stenosis
Authors: HELLER STANLEY J. , CARLETON RICHARD A.
Published: June 2012

Twenty-five patients with pure mitral stenosis and nine normal subjects were studied by selective left ventricular cineangiocardiography. Left ventricular volumes were measured at end systole, throughout diastole, and at end diastole. Although filling curves showed that the left ventricles filled slowly in patients with mitral stenosis, normal end-diastolic volumes were attained provided diastole lasted 400 msec. Despite normal end-diastolic volumes, end-systolic volumes were significantly larger (
P
< 0.0005) in the patients with mitral stenosis (av=64.6 ml) than in normal subjects (30.8 ml). Correspondingly, left ventricular ejection fractions were significantly lower (
P
< 0.0005) in the patients with mitral stenosis (55.7%) than in the normal subjects (76.7%).

Qualitative analysis of the cineangiocardiograms demonstrated that 20 patients with mitral stenosis had distortion, immobility, and rigidity of the posterobasal area of the left ventricle.

It is hypothesized that a rigid "mitral complex" immobilizes the posterobasal area of the left ventricle in patients with mitral stenosis, thereby impairing left ventricular contraction, and that this impairment is an important factor in the reduced cardiac output of these patients.
Left Ventricular Pressure-Volume Alterations and Regional Disorders of Contraction During Myocardial Ischemia Induced by Atrial Pacing
Authors: DWYER EDWARD M.
Published: June 2012

Left ventricular function, pressure-volume relationships, and wall motion were studied by sequential cineventriculography during acute myocardial ischemia, induced by atrial pacing, in 10 subjects. Observations made in this group were contrasted to data obtained during atrial pacing in a smaller normal group.

An acute alteration in the pressure-volume relation occurred in five subjects during ischemia with an elevation of the left ventricular end-diastolic pressure, associated with a declining end-diastolic volume.

A deterioration in ventricular function, as manifested by a rightward shift of the ventricular function curve, was also observed in eight of the angina group. A more severe instance of myocardial failure was seen in one patient, who, during angina, demonstrated a marked increase of both left ventricular end-diastolic pressure and end-diastolic volume.

Asynergy of left ventricular contraction occurred acutely during angina and was usually manifested by regional akinesis or hypokinesis. Diminished wall motion was often found in more than one region, reflecting multiple vessel involvement. We were generally able to correlate the dynamc alteration in wall motion with deteriorating ventricular function.
The Frontal Plane Vectorcardiogram in Old Inferior Myocardial Infarction
Authors: YOUNG ELIOT , LEVINE HAROLD D. , VOKONAS PANTEL S. , KEMP HARVEY G. , WILLIAMS RICHARD A. , GORLIN RICHARD
Published: June 2012

The mid-to-late part of the frontal plane QRS loop (Frank lead system) of 150 consecutive subjects with an old inferior myocardial infarction was analyzed. During the acute episode all cases had to satisfy Myers' classical ECG criteria for the diagnosis. The vectorcardiogram was recorded months to years later.

As a result of this analysis and in order to prevent overlap with values found in 450 normal control subjects, four VCG criteria are proposed for this diagnosis.

The VCGs of 75 of the 150 patients fulfilled one or more of the four VCG criteria. The ECG, done at the time of VCG, satisfied Myers' or Goldberger's criteria or both criteria in 33 of these 75 patients, and an additional 24 of the 150 fulfilled either or both of these ECG criteria but had none of the four VCG criteria.

Among 131 consecutively catheterized subjects who had significant disease of one or more major coronary arteries, 40 fulfilled one or more of the VCG criteria. Thirty-six of the 40 showed significant stenosis of at least the right coronary artery, and the other four, of at least the left circumflex but not of the right coronary artery. Six of these 40 fulfilled Myers' or Goldberger's criteria. Five of the 131 fulfilled either or both of these ECG criteria but none of the four VCG criteria.
The Regulation of Cerebral Blood Circulation in Subclavian Steal Syndrome
Authors: SOLTI FERENC , ISKUM MIKLÓS , PAPP SÁNDOR , TURBÓK ESZTER , NAGY JULIA
Published: June 2012

Blood flow to the brain was studied in 11 patients suffering from subclavian steal syndrome. The venous isotope-dilution method was used to measure total blood flow to the brain and the dye-dilution method with intravenous administration of 50 mg of Evans blue was used to determine cardiac output. Cerebral blood flow was significantly lower in the 11 patients with subclavian steal syndrome than in the control group, and the O
2
consumption of the brain was low, cerebral resistance was elevated, and the cerebral fraction of the cardiac output was decreased in comparison with the controls.

The effect of occlusion of the ipsilateral brachial artery was studied in 10 of the patients with subclavian steal syndrome. The cerebral blood flow and the cerebral fraction of the cardiac output increased significantly as a result of the occlusion in these patients.

Studies on three patients after surgical correction of the lesion in the subclavian artery showed significant improvement in the cerebral circulation.
Bacterial Endocarditis Following Homograft Replacement of the Aortic Valve
Authors: CLARKSON PATRICIA M. , BARRATT-BOYES BRIAN G.
Published: June 2012

Endocarditis was encountered on an aortic homograft valve in 14 of 539 patients, giving a total incidence of 2.6%. It was an early postoperative complication in five patients (0.9%), and only one of these survived. Four hundred and six hospital survivors were followed for periods up to 76 mo. Nine of these patients (2.2%) developed infection of the homograft valve 11 to 66 mo postoperatively and four survived. Late endocarditis occurred more commonly in patients with a history of endocarditis prior to operation (
P
=0.005). In only one of the nine patients with late endocarditis was the infection related to a peripheral leak around the graft. Most patients with late endocarditis rapidly developed severe homograft valve incompetence, which was the cause of death in four of the nine. Six patients were reoperated on and three of these survived.
Right Ventricular Anomalous Muscle Bundle
Authors: FORSTER J. W. , HUMPHRIES J. O.
Published: June 2012

Eighteen patients with right ventricular anomalous muscle bundles associated with ventricular septal defect and one patient with isolated anomalous muscle bundle were studied. The clinical differentiation of these patients from those with isolated ventricular septal defects or tetralogy of Fallot was difficult. Eleven patients were asymptomatic at the time of diagnosis; eight had various degrees of dyspnea on exertion, with three of these having cyanosis. A physiologically split second sound with a pulmonic component of normal intensity and a diffuse thrill and holosystolic murmur maximal at the lower left sternal border suggest the diagnosis. Chest X-rays and electrocardiograms usually show evidence of right ventricular hypertrophy, but may suggest left ventricular hypertrophy in the presence of a large left-to-right shunt. However, the diagnosis is best made by cardiac catheterization with measurement of a pressure gradient in the body of the right ventricle and by selective angiography with the demonstration of a wedge-shaped filling defect in the right ventricle. Progressive obstruction by the muscle bundle occurred in four of seven patients who had repeated catheterization associated with the development of electrocardiographic changes of right ventricular hypertrophy. To date, 11 patients have had surgery; one died before surgery; and surgery is being planned for the remaining patients.
Effects of Ouabain on the Left Ventricular Response to Exercise in Patients with Angina Pectoris
Authors: GLANCY D. LUKE , HIGGS LAWRENCE M. , O'BRIEN KEVIN P. , EPSTEIN STEPHEN E.
Published: June 2012

The response of the left ventricle to a level of supine bicycle exercise that induced angina, and the effects of ouabain (0.01 mg/kg) on this response were evaluated in 14 patients with coronary arterial disease. Before administration of ouabain, exercise was associated with depressed pumping performance of the left ventricle in four patients: stroke work fell with exercise while left ventricular end-diastolic pressure (LVEDP) increased. In five patients left ventricular (LV) performance was not frankly depressed, but nevertheless was abnormal: stroke work increased, but was accompanied by an inordinately large rise in LVEDP. In the remaining five patients LV function was essentially normal. Ouabain improved LV performance at rest in only a minority of patients, but during the stress of exercise, LV hemodynamics were improved by ouabain in 12 of the 14 patients. Five patients, however, continued to show either depressed or abnormal function with exercise after they were given ouabain. As judged by the relationship of LVEDP to LV peak dp/dt, left ventricular contractility was increased by ouabain in most patients both at rest and during exercise. Despite its beneficial effects on left ventricular performance, ouabain did not consistently alter either exercise tolerance or the LV tension-time index and pressure-rate product at which angina occurred.
External Isovolumic Contraction Times and Left Ventricular Ejection Time/External Isovolumic Contraction Time Ratios at Rest and After Exercise in Coronary Heart Disease
Authors: ARONOW WILBERT S. , BOWYER ALLEN F. , KAPLAN MARVIN A.
Published: June 2012

Twenty-one men with coronary heart disease had supine phonocardiograms and carotid pulse tracings at rest, immediately after upright bicycle exercise, and 3 min after exercise 1 day preceding left ventricular cineangiography. External isovolumic contraction times (EICT) and left ventricular ejection time/EICT (LVET/EICT) ratios were computed and correlated with ejection fractions and ventricular end-diastolic volumes determined from right anterior oblique cineangiograms. For the ejection fraction, the highest correlations were with the LVET/EICT ratios immediately after (r = 0.71) and 3 min after exercise (r = 0.69). For the end-diastolic volume, the highest correlations were with the LVET/EICT ratios immediately after (r = –0.79) and 3 min after exercise (r = –0.80). The LVET/EICT ratio immediately after exercise differentiated between 13 patients with an ejection fraction of 50% or greater and eight patients with an ejection fraction <50%. These data indicate that the LVET/EICT ratio after exercise is a good noninvasive measurement for assessment of myocardial contractility.
Factors Influencing Infarct Size Following Experimental Coronary Artery Occlusions
Authors: MAROKO PETER R. , KJEKSHUS JOHN K. , SOBEL BURTON E. , WATANABE TAN , COVELL JAMES W. , ROSS JOHN , BRAUNWALD EUGENE
Published: June 2012

The purpose of this study was the determination of whether hemodynamic and pharmacologic factors influence the extent and severity of myocardial necrosis produced by coronary occlusion. In 48 dogs, 10 to 14 epicardial leads were recorded on the anterior surface of the left ventricle in the distribution and vicinity of the site of occlusion of a branch of the left anterior descending coronary artery. The average S-T segment elevation for each animal was determined at 5-min intervals after occlusion. This elevation was used as an index of the presence and severity of myocardial ischemic injury. The number of sites showing this elevation provided an additional measure of the size of the injured area. Occlusion alone raised the average S-T segment elevation from 0.22 ± 0.04 to 3.32 ± 0.37 mv (SEM). Isoproterenol, ouabain, glucagon, bretylium, and tachycardia given prior to a repeated occlusion increased the severity and extent of ischemic injury, while propranolol decreased it. Elevation of arterial pressure with methoxamine reduced the occlusion-induced S-T segment elevation, and lowering of the mean arterial pressure by hemorrhage had the opposite effect. In 19 additional experiments, propranolol, isoproterenol, and alterations in arterial pressure produced similar alterations in S-T segment elevation when these interventions were applied as long as 3 hr after ligation. In a third group of dogs, myocardial creatine phosphokinase (CPK) activity was determined 24 hr after occlusion at the same sites at which epicardial electrocardiograms were taken. Depression of myocardial CPK activity in injured portions of the left ventricle 24 hr after coronary artery ligation correlated well with S-T segment elevation in the same sites 15 min after ligation. Moreover, isoproterenol increased and propranolol decreased the area of depression of myocardial CPK activity. We conclude that the hemodynamic status and neurohumoral background at the time of occlusion and for up to 3 hr thereafter can alter the extent and severity of myocardial ischemic injury and myocardial necrosis.
Analysis of Left Ventricular Function by Atrial Pacing
Authors: PARKER JOHN O. , KHAJA FAREEDUDDIN , CASE ROBERT B.
Published: June 2012

With the technique of right atrial pacing, left ventricular function was assessed in 21 normal subjects and in 13 patients with elevated left ventricular filling pressures. Since cardiac output does not change significantly with atrial pacing, the stroke volume decreases as an inverse function of the pacing rate. Stroke volume can thus be varied over a wide range, and by simultaneous measurement of left ventricular end-diastolic pressure, pacing ventricular function curves can be obtained. The calculated average slope for the ventricular function curve relating stroke volume index to left ventricular end-diastolic pressure was steeper in the normal subjects than in the group with elevated left ventricular end-diastolic pressure, but considerable overlap occurred between the groups. However, in individual patients the pacing ventricular function curve appears useful in assessment of the effect of interventions that augment or depress ventricular performance.
Radiologic Notes in Cardiology
Authors: BARON MURRAY G.
Published: June 2012

Obscuration of the superior margin of the aortic knob together with a widening of the mediastinal shadow to the left is a common sign of coarctation of the aorta. It is easily seen on the routine frontal chest film and may be the first detected evidence of the lesion. Although the appearance is not pathognomonic of a coarctation, it certainly indicates the need for further studies.
Congenital Heart Disease in 56,109 Births Incidence and Natural History
Authors: MITCHELL S. C. , KORONES S. B. , BERENDES H. W.
Published: June 2012

Within a prospective study of 56,109 total births, 457 youngsters have been found to have congenital heart disease. The overall incidence is 8.14/1000 total births, 8.0/1000 for the Negro and 8.3/1000 for the white. A specific lesion has been identified for each patient and lesion frequencies given for each class of patient, stillbirth, neonatal death, infant death, childhood death, and survivors. The percentage of autopsies was 93% in the stillbirths, 89% in the neonatal deaths, and 76% for those dying after 28 days of age. Of those classified as having definite congenital heart disease, 93% have been examined by a pediatric cardiologist. The average follow-up time for the 272 survivors is 3 years. Thirty-five per cent of patients with ventricular septal defect surviving more than 6 months had their lesion close spontaneously; one-half of the survivors with tetralogy of Fallot were "atypical," and essentially equal numbers of blacks and whites had all types of coarctation of the aorta in line with the study population, which is 47% black and 53% white.
Ventricular Septal Defect and Ventricular Aneurysm Secondary to Acute Myocardial Infarction
Authors: FREENY PATRICK C. , SCHATTENBERG THOMAS T. , DANIELSON GORDON K. , MCGOON DWIGHT C. , GREENBERG BURTON H.
Published: June 2012

Four cases of ventricular septal defect and ventricular aneurysm after myocardial infarction are reported. The clinical findings and surgical results in these four cases and in eight previously reported patients with this combination of complications are summarized. Resection of the ventricular aneurysm and closure of the ventricular septal defect appear indicated, both on theoretical grounds and in view of the excellent results observed in six patients who underwent combined repair. In one of our patients, closure of the ventricular septal defect and resection of the ventricular aneurysm were possible with only a single suture line, as these defects were anatomically contiguous.
Atrial Pacing and Exercise in the Evaluation of Patients with Angina Pectoris
Authors: BAHLER R. C. , MACLEOD C. A.
Published: June 2012

The anginal threshold was determined by atrial pacing in 23 patients with coronary artery disease. Twelve of the 23 subjects also performed supine exercise at progressive workloads until the onset of angina. Atrial pacing produced a fall in left ventricular stroke work index and left ventricular end-diastolic pressure (LVEDP); cardiac output increased, and, with the onset of angina, left ventricular dysfunction was sometimes evidenced, either by an increase in LVEDP or by an abnormal LVEDP in the postpacing period. In contrast, exercise consistently produced left ventricular dysfunction. The tension-time index at the onset of angina was similar whether the pain was induced by pacing or exercise.

The atrial rate that induced angina bore little relationship to either the clinical or anatomic severity (outlined by coronary arteriography) of coronary artery disease. The exercise workload that produced angina correlated inversely with the quantitated coronary disease. Although atrial pacing is a convenient tool for the study of ischemic ventricular dysfunction, exercise testing provides a more reliable index of functional and anatomic severity of coronary artery disease.
Radiologic Notes in Cardiology
Authors: BARON MURRAY G.
Published: June 2012

The anatomic hallmark of a double-outlet right ventricle is the separation of the mitral and aortic valves by a band of myocardium. The two valves remain in contact with each other in tetralogy of Fallot no matter how far anteriorly the aorta is displaced. The mitral-aortic relationship can usually be well demonstrated in both anomalies by selective right ventricular angiocardiography.
In Vivo Pressure-Radius Relationships of the Pulmonary Artery in Children with Congenital Heart Disease
Authors: JARMAKANI JAY M. M. , GRAHAM THOMAS P. , BENSON D. WOODROW , CANENT RAMON V. , GREENFIELD JOSEPH C.
Published: June 2012

The effects of either increased pulmonary artery blood flow or pressure on the magnitude of the radius and the dynamic properties of the right pulmonary artery were studied angiographically in 162 patients during cardiac catheterization. Patients were divided into seven groups according to their hemodynamic findings. The right pulmonary artery radius was measured during systole and diastole, from the projected films, at the midpoint between the bifurcation of the main pulmonary artery and the bifurcation of the right pulmonary artery. The mean pulmonary artery radius was increased in patients with either increased pulmonary blood flow or pressure, and in patients with isolated valvular pulmonic stenosis. Both the pressure-strain elastic modulus (stiffness index) and the tension-radius regression were different from normal only in patients with increased pulmonary artery pressure regardless of the pulmonary blood flow. This finding indicates that the pulmonary artery is stiffer in patients with pulmonary hypertension but that its elastic properties are not altered secondarily to increased blood flow.
Angiocardiographic Evaluation of Valvular Insufficiency
Authors: BARON MURRAY G.
Published: June 2012

Incompetence of any of the cardiac valves can be easily evaluated by selective angiocardiography. Factitious insufficiency may result from faulty catheter placement or from ventricular extrasystoles caused by the pressure injection of the contrast agent. False negative results are almost nonexistent, and if no insufficiency is seen on a technically adequate angiocardiogram, the valve can be considered to be competent.
His Bundle Electrograms in Patients with Short P-R Intervals, Narrow QRS Complexes, and Paroxysmal Tachycardias
Authors: CASTELLANOS AGUSTIN , CASTILLO CECAR A. , AGHA ABDUL S. , TESSLER MICHAEL
Published: June 2012

His bundle electrograms were recorded in three patients with short P-R intervals, narrow QRS complexes, and a history of paroxysmal tachycardias. During sinus rhythm or atrial stimulation with long cycle lengths, the shortening of the P-R interval was due to a decrease in the low right atrium-His (LRA-H) interval (representing A-H conduction time). The latter was also short during retrograde (V-A) conduction. These findings support the existence of an A-V nodal bypass operation in both directions. In one patient, the LRA-H interval did not lengthen when the atrial rate was increased. Intermittent atrial pacing was performed in the two other patients. The LRA-H interval was short at long coupling intervals, but it started to increase (progressively) at a given Stimulus
1
-Stimulus
2
interval. Apparently, the refractory period of the accessory bundle was encountered so that the impulse was propagated, with various degrees of delay, through the A-V node. A James bundle need not be present in all patients with similar electrocardiograms. Abnormalities of unknown origin could cause this phenomenon. Reciprocating tachycardias were induced by stimulation of the atria in one patient. The triggering beat consistently had a long A-V conduction time. Although in this case retrograde (V-A) propagation most probably occurred through the accessory communication, the possibility of a functional intranodal dissociation of a single anatomical pathway could not be excluded.
The Essential Role of Atrioventricular Conduction Delay in the Initiation of Paroxysmal Supraventricular Tachycardia
Authors: GOLDREYER BRUCE N. , DAMATO ANTHONY N.
Published: June 2012

Studies have shown that in patients with paroxysmal supraventricular tachycardia (SVT), spontaneous or stimulated atrial premature depolarizations (APD) falling within a specific portion of the relative refractory period of the atrioventricular (A-V) conduction system initiate SVT. The present study was designed to determine whether the A-V nodal conduction delay these APDs exhibit, or their coupling interval, is essential for the initiation of SVT. Multiple episodes of SVT were initiated and terminated by single APDs in four patients with a history of paroxysmal SVT. The atria were then paced at numerous fixed rates in excess of the spontaneous sinus rate. In each patient, at atrial rates where progressive A-V nodal conduction delay occurred from beat to beat (Wenckebach cycles), a specific degree of A-V nodal conduction delay always resulted in atrial reentry or SVT. Although the atrial coupling interval was considerably longer during Wenckebach cycles initiating SVT than for single APDs resulting in the arrhythmia, the prolongation of A-V nodal conduction was identical. Independent of atrial coupling interval, a requisite degree of A-V nodal conduction delay always resulted in atrial echoes or SVT. This supports the conclusion that SVT results from atrial reentry via the A-V node.
Absence of Elastica from Inner Half of Aorta
Authors: MACMAHON H. EDWARD , CHAMBERS WILLIAM J.
Published: June 2012

Multiple dissecting aneurysms were found in the course of an autopsy on a 52-year-old male patient who had expired suddenly as a result of a massive pericardial tamponade. Two of these aneurysms involved the aorta. The others involved muscular arteries, namely, the superior mesenteric and the splenic. In the case of the aorta, there was an absence of elastica from the entire inner half of the media, leaving the fabric of the outer half intact. The course of dissection in the case of each aneurysm lay along the line of demarcation separating the inner from the outer half of the media. This very unusual pattern, showing an absence of elastic lamina in the inner half of the media, differs remarkably from the changes that are commonly seen in dissecting aneurysms of this large elastic artery. Neither the etiology nor pathogenesis of this defect is known. The recognition that such a disease exists is only the first step toward its solution.
Physiologic Correction of Transposition of the Great Arteries
Authors: WALDHAUSEN JOHN A. , PIERCE WILLIAM S. , PARK C. DICK , RASHKIND WILLIAM J. , FRIEDMAN SIDNEY
Published: June 2012

The total management of a group of 32 patients with transposition of the great arteries (TGA) is reported. All but one had required creation of an atrial septal defect in infancy. Eighteen patients had no associated cardiac defects, and physiologic correction was performed between 8 months and 9½ years of age. The only death in this group occurred 9 months after operation. Eight of nine patients with TGA and an associated ventricular septal defect (VSD) had required pulmonary artery banding in infancy. Physiologic correction was performed between 2¼ and 6 years of age. Three of these patients died during the postoperative period, and one died 9 months after operation. Two patients had TGA and pulmonary stenosis (PS). Physiologic correction was performed at 2 1/3 and 3¾ years of age. Both patients have done well. Three patients had TGA, VSD, and PS. Total correction was performed between 2 1/3 and 3½ years of age. All three patients died in the postoperative period. The over-all operative mortality was 19%.

Our present plan of management has evolved from the experience reported above. All infants with TGA have balloon atrioseptostomy. If no VSD is present, physiologic correction is performed between 1 and 2 years of age. Patients with TGA and a VSD are catheterized at 8 months of age, and pulmonary banding is performed if pulmonary artery hypertension is present. Physiologic correction is performed at about 4 years of age. Patients with TGA, VSD, and PS may require systemicpulmonary artery anastomosis. Correction at 5 years of age with the use of a homograft from the right ventricle to the pulmonary artery, as described by Rastelli and his associates, is recommended because of the poor results obtained with an intra-atrial baffle in this group.
Diagnostic and Therapeutic Uses of Atrial Pacing
Authors: DESANCTIS ROMAN W.
Published: June 2012

There are occasions when atrial pacing can be usefully employed both diagnostically and therapeutically. Diagnostically, atrial pacing provides mechanisms for easily, safely, and reproducibly stressing the heart that can help in the evaluation of patients with a variety of cardiac disorders. It is particularly useful in the assessment of patients with coronary disease.

Therapeutically, atrial pacing has been applied in four general areas: (1) to terminate or slow supraventricular tachyarrhythmias; (2) to accelerate the heart rate in patients with sinus bradycardia and intact atrioventricular conduction; (3) to suppress ventricular irritability; and (4) to augment cardiac output. Techniques of atrial pacing are discussed. Currently, a major problem with both temporary and long-term pervenous atrial pacing is erratic pacing. The development of electrodes and pacemakers designed specifically for atrial pacing, as well as further experience with stimulation from the coronary sinus may lead to more reliable pacing.
Emergency Aortocoronary Bypass for Impending or Extending Myocardial Infarction
Authors: HILL J. DONALD , KERTH WELLIAM J. , KELLY JOHN J. , SELZER ARTHUR , ARMSTRONG WILLIAM , POPPER ROBERT W. , LANGSTON MANLY F. , COHN KEITH E.
Published: June 2012

Emergency coronary arteriography and aortocoronary bypass were successfully performed in three patients with preinfarction angina. Four patients with impending extension of a recent infarction died during or after aortocoronary bypass surgery. Aortocoronary bypass may improve angina and prevent infarction in selected instances of preinfarction angina. In patients with recent infarction and impending extension the risk of surgery appears to be prohibitively high.
Ultrasonic Measurement of Left Ventricular Wall Motion in Acute Myocardial Infarction
Authors: INOUE KIYOSHI , SMULYAN HAROLD , MOOKHERJEE SAKTIPADA , EICH ROBERT H.
Published: June 2012

The time-motion representation of the echogram was used to evaluate the left ventricular posterior wall motion in myocardial infarction. The left ventricular posterior wall echo was obtained in 10 normal subjects and 26 patients with chest pain admitted to a coronary care unit, including 11 with acute myocardial infarction (group 1), nine with old myocardial infarction (group 2), and six with chest pain of miscellaneous origin (group 3). The total amplitude of posterior wall excursion, left ventricular isometric contraction time, left ventricular systolic ejection time, and mean posterior wall velocity (ratio of posterior wall excursion to ejection time) were measured. By using the measurements of posterior wall excursion, mean posterior wall velocity, and isometric contraction time, group 1 patients were differentiated from those of groups 2 and 3 and from the normal subjects (all
P
< 0.01). The data from patients in groups 2 and 3 were not statistically different from those of normal subjects. The measurements obtained by the time-motion curve of the left ventricular posterior wall echo appear to be of value in the bedside evaluation of acute myocardial infarction.
Efficacy of Isoproterenol-Glucagon Infusion in Patients with Heart Disease
Authors: POLUMBO RALPH A. , LEIGHTON RICHARD F. , WEISSLER ARNOLD M.
Published: June 2012

Isoproterenol and glucagon were administered separately and in combination by constant rate of intravenous infusion to 13 patients with organic heart disease. Glucagon produced modest increases in cardiac output, heart rate, and arterial pulse pressure. Isoproterenol produced increases in cardiac output and heart rate greater than that achieved with glucagon alone and also increased arterial pulse pressure, stroke volume, and mean rate of left ventricular ejection and decreased systemic vascular resistance.

The same doses of isoproterenol and glucagon in combination produced a greater effect on cardiac output than that achieved with either drug alone and had a greater effect on heart rate and arterial pulse pressure than did glucagon alone. There was no increase in the side effects of either drug associated with their administration in combination.

The present study suggests that the clinical usefulness of glucagon may be enhanced by administering glucagon in combination with isoproterenol in order to obtain the additive hemodynamic benefit of these drugs while minimizing their undesirable side effects.
Glucose Intolerance in Nonischemic Cardiac Disease
Authors: ETTINGER PHILIP O. , OLDEWURTEL HENRY A. , DZINDZIO BARRY , SETHI VIRENDER , REGAN TIMOTHY J.
Published: June 2012

To investigate hemodynamic and neurohumoral factors as a basis for glucose intolerance in cardiac patients without ischemic heart disease, intravenous glucose tolerance tests were performed on 70 patients aged 14 to 69 years. The mean glucose fractional disappearance rate (G
k
) for 41 patients less than age 50 was 1.19 ± 0.07% fall in glucose/min, while in 19 normal subjects, it was 1.60 ± 0.14,
P
<0.01. The decreased G
k
was independent of age and lipid levels, and was directly related to a reduced plasma concentration of immunoreactive insulin. The glucose response to tolbutamide of 40 patients was similarly reduced and correlated with G
k
.

Since enhanced adrenergic stimulation may be present in cardiac patients with resultant reduction of insulin secretion, the effects of alpha-and beta-adrenergic blockade were examined in two groups of cardiac patients. G
k
was unchanged after administration of phenoxybenzamine and propranolol. Since a reduced cardiac output correlated with diminished G
k
, the influence of sustained improvement after corrective cardiac surgery was evaluated in 13 patients. Postsurgical increments of resting cardiac output were usually associated with lower fasting insulin levels, enhanced clearance of administered glucose, and a more rapid rise of plasma insulin to higher peak levels, followed by a relatively rapid decline. Enhanced insulin response to tolbutamide after surgery in seven of these patients was also demonstrated. It is suggested that chronically reduced levels of cardiac output can result in reduced insulin secretion and in glucose intolerance and that these may be reversed with improved cardiac function.
Effect of Volume Expansion on the Anginal Threshold
Authors: KHAJA FAREEDUDDIN , SANGHVI VIJAY , MARK ALEXANDER , PARKER JOHN O.
Published: June 2012

The clinical and hemodynamic effects of rapid atrial pacing were studied in 13 patients with coronary artery disease and four normal subjects before and following acute expansion of blood volume with low molecular weight dextran. Five patients developed angina during the initial pacing period. In two of these five patients angina recurred with infusion alone, and all five of them experienced pain during the second pacing period. The anginal threshold averaged 5 min (range, 1 to 8 min) before infusion and 1.8 min (range, 0 to 5 min) following infusion. Four patients with coronary artery disease remained free of pain during the first pacing period, one of these developed pain with infusion alone, and all developed pain during pacing following infusion, the anginal threshold being 2 min (range, 0 to 3 min). The remaining four patients with coronary artery disease did not develop angina during either pacing period.

Administration of dextran was accompanied by an increase in left ventricular end-diastolic pressure in all patients during sinus rhythm and during atrial pacing. Although left ventricular volume was not determined, changes in left ventricular end-diastolic pressure were interpreted as showing directional changes in left ventricular volume. Analysis of the factors affecting myocardial oxygen requirements during the two pacing periods indicated that heart rate, systemic arterial pressure, and maximal rate of rise of left ventricular pressure were similar. Although the tension-time index rose 10.6%, the major change was the increase in left ventricular end-diastolic pressure and presumably in left ventricular volume. This increase in left ventricular volume is considered responsible for the increase in myocardial oxygen requirements following infusion of dextran as determined by the decrease in the anginal threshold in each patient of the angina group.
An In Vitro Model of Paroxysmal Supraventricular Tachycardia
Authors: WIT ANDREW L. , GOLDREYER BRUCE N. , DAMATO ANTHONY N.
Published: June 2012

An in vitro preparation of rabbit right atrium, including the A-V node (AVN) and bundle of His, was utilized to evaluate the mechanism of paroxysmal supraventricular tachycardia (SVT). Microelectrode recordings from atrium and AVN were obtained. During sinus rhythm the atrial cycle was explored with atrial premature depolarizations (APD). Fifty episodes of an arrhythmia with characteristics identical to SVT in man were produced in six of 40 rabbits. In vitro, SVT: (1) was initiated by a single APD showing prolonged conduction in the AVN; (2) had initial cycles similar to atrial echoes; (3) in most instances showed 1:1 A-V conduction; (4) lasted 20 to 500 cycles; and (5) could be ended by a single APD which penetrated the AVN. Reentry in the upper AVN was established by the recording of action potentials from nodal cells which showed marked electrotonic "humps" during repolarization. SVT and atrial echoes could not be produced after damaging or sectioning the upper AVN. An in vitro model of SVT supports the hypothesis that this arrhythmia results from reentry within the AVN.
Hemodynamics of Uremic Anemia
Authors: NEFF MARTIN S. , KIM KWAN E. , PERSOFF MICHAEL , ONESTI GADDO , SWARTZ CHARLES
Published: June 2012

This study was undertaken to assess the importance of an elevated cardiac output in the generation of the hypertension associated with chronic renal failure. Forty stable uremic patients on a program of maintenance hemodialysis underwent hemodynamic studies. Cardiac index measured by dye dilution was found to be significantly elevated. Calculated peripheral vascular resistance was normal despite elevated blood pressure. Six patients underwent serial hemodynamic studies over a period of 6 to 12 weeks while being transfused with packed red blood cells to a normal hematocrit. Blood volume and body weight were constant during the study period. Cardiac index decreased during transfusion, reaching a normal level at a hematocrit of 30%. Diastolic blood pressure progressively rose, averaging an increase of 20 mm Hg at a hematocrit of 40%. Peripheral vascular resistance increased by 80% at a hematocrit of 40%.

We concluded that the elevation of cardiac index in uremic patients is secondary to anemia and is reversible when the hematocrit is raised over 30%. The high cardiac index is not responsible for hypertension because restoration of cardiac index to normal by transfusion raises blood pressure rather than lowers it.
Digital Systolic Pressures in the Lower Limb in Arterial Disease
Authors: CARTER S. A. , LEZACK J. D.
Published: June 2012

Systolic pressures were measured by using pneumatic cuffs on the second toe, ankle, and arm. In the absence of clinically evident peripheral vascular disease, digital pressure expressed as a percentage of the brachial pressure averaged 87% and was not significantly different in older normal persons, patients with hypertension, diabetes mellitus, or coronary artery disease from that in young normal subjects. Digital pressures were decreased in patients with arteriosclerosis and thromboangiitis obliterans, or Raynaud's phenomena. Mean digital pressures correlated well with clinical and angiographic findings. In arteriosclerosis obliterans digital pressures in the limbs with claudication averaged 43% of the brachial pressure, and in patients with rest pain or skin lesions, or both, 21%. The ankle-to-toe pressure difference was increased in the majority of patients with thromboangiitis obliterans and in some diabetics with arteriosclerosis obliterans. The results indicate that digital pressure expressed as percentage of brachial pressure is a good index of the severity of the overall occlusive process, whereas the ankle-to-toe pressure difference may provide a useful index of the disease in the small distal arteries.
Survival After Starr-Edwards Aortic Valve Replacement
Authors: SHEAN FREDRIC C. , AUSTEN W. GERALD , BUCKLEY MORTIMER J. , MUNDTH ELDRED D. , SCANNELL J. GORDON , DAGGETT WILLARD M.
Published: June 2012

A series of 507 patients who underwent Starr-Edwards aortic valve replacement is reported. Four hundred fifty-five of these patients were adequately followed an average of 36 months. Of this number, 339 patients (75%) are alive, and 116 (25%) have died. There was an operative mortality of 10.8% and a late mortality of 13.4%. Patients with mixed aortic stenosis and regurgitation had a significantly lower cumulative mortality than patients with pure stenosis or regurgitation. Complications related to the valvular prosthesis itself were frequent. Although the great majority were minor, prosthetic complications caused a significant number of deaths and considerable morbidity. Myocardial disease was the other significant limiting factor in survival. Preoperative cardiac index and functional classification were valuable in predicting long-term survival, but age at time of surgery and type of preoperative symptoms were of lesser prognostic value.
Increased Arteriovenous Oxygen Difference After Physical Training in Coronary Heart Disease
Authors: DETRY JEAN-MARIE R. , ROUSSEAU MICHEL , VANDENBROUCKE GENEVIEVE , KUSUMI FUSAKO , BRASSEUR LUCIEN A. , BRUCE ROBERT A.
Published: June 2012

A preliminary study of 12 male patients (mean age, 47.8 years) with coronary heart disease (six with angina pectoris and six with prior myocardial infarction but without angina) was conducted according to a common protocol in Seattle, Washington, and Louvain, Belgium. Maximal oxygen intake (V

o
o2

max) and hemodynamic studies at rest and at two or three levels of submaximal exercise in the upright position were obtained before and after a 3-month physical training program that involved three sessions of 45 min/week. "V

o
o2

max" increased 22.5% (
P
< 0.0001) with physical training. Changes in maximal heart rate occurred in the patients with angina (+8.4%) but not in those without angina (+0.8%). At rest and at each submaximal exercise, heart rate, mean blood pressure, and cardiac output decreased after training, whereas stroke volume was unchanged and arterio-mixed venous oxygen (A-V

o
o2

) difference increased. The pressure-rate product and the left ventricular work decreased after training. The classic posttraining bradycardia was compensated not by a higher stroke volume but by an increased A-V

o
o2

difference which resulted from both a higher arterial oxygen content and an increased peripheral oxygen extraction. The latter was more apparent when exercises of the same relative intensity were compared.

Thus, benefits with physical training in coronary patients result at submaximal exercise level from enhanced arterial oxygen content and peripheral extraction and secondarily from lower hemodynamic stress on ischemic myocardium. Increased maximal A-V

o
o2

difference probably explains most of the increase in "V

o
o2

max" with physical training in coronary patients not limited by angina pectoris.
The Angiocardiographic Diagnosis of Valvular Stenosis
Authors: BARON MURRAY G.
Published: June 2012

The angiocardiographic diagnosis of valvular stenosis depends on demonstrating a limitation in the motion of the cusps or leaflets so that the valve cannot open completely. In general, this technique is best for study of the pulmonic and aortic valves although a fairly accurate evaluation of the pliability or rigidity of a stenotic mitral valve can also be made. The normal valve cusps are usually not seen during systole, but, when they are stenotic, they assume a domelike configuration, bulging in the direction of blood flow. This is easily seen and is quite characteristic. Despite the degree of stenosis, so long as the cusps or leaflets are not severely fibrotic, they can appear normal in their diastolic position.
Measurement of Heart Chamber Volumes by Analysis of Dilution Curves Simultaneously Recorded by Scintillation Camera
Authors: ISHII YASUSHI , MACINTYRE WILLIAM J.
Published: June 2012

After a peripheral injection of Technetium-99
m
, an Anger scintillation camera placed over the precordium of nine patients without and three patients with hemodynamic abnormalities was used to record in rapid sequence the flow of the injected material through the central circulatory system. After the data were processed as sequential frames of digitized spatial matrices, the position of various chambers or compartments was identified and dilution curves from six sites were obtained, providing a series of input-output relations through the central circulatory system, i.e., superior vena cava, right atrium, right ventricle, lung, left atrium, and left ventricle. These relations were assumed to be cascaded as a series of first order lag systems, with or without time delay, on an analog computer, which allowed estimation of the time constant of the transfer function of each chamber or compartment (volume/flow) by reducing the problem to a consecutive, one-parametric manipulation. Measurement of the flow rate through the series (cardiac output) permitted the volume of each chamber to be estimated. Results correlated well with mean values established by other methods.