bluuebunny/crossref_metadata_2025 huggingface dataset:
A Study of Atrioventricular Conduction in Atrial Fibrillation and Flutter in Man Using His Bundle Recordings
Authors: LAU SUN H. , DAMATO ANTHONY N. , BERKOWITZ WALTER D. , PATTON ROBERT D.
Published: June 2012

Seven patients with atrial fibrillation and six patients with atrial flutter were studied using the technic of His bundle recordings. All 13 patients received digitalis. In atrial fibrillation each QRS complex (except for premature ventricular beats) was preceded by a single His bundle deflection. Complete block distal to the His bundle was not observed. Thus, the zone of concealment could be localized to the region proximal to the His bundle. The clinical findings were confirmed in three animal experiments. In atrial flutter the nonconducted P waves were also blocked proximal to the His bundle. In atrial fibrillation aberrant ventricular beats were distinguished from premature ventricular beats by the presence of a preceding His deflection in the former and its absence in the latter.
Atrial Tachysystole (Flutter?) with Apparent Exit Block
Authors: JAVIER ROGER P. , NARULA ONKAR S. , SAMET PHILIP
Published: June 2012

A case of atrial tachysystole with apparent exit block is reported in which the basic cycle length of atrial activity is 260 msec. Simultaneous right intra-atrial electrograms show cycle lengths of 510 to 780 msec which are roughly multiples of 260 msec establishing the diagnosis of exit block. Rapid atrial stimulation (1,200/min) to overdrive the rapid ectopic atrial pacemaker was only transiently successful in converting the arrhythmia to atrial fibrillation with a slower ventricular response. Two days later the rhythm converted to normal sinus rhythm (cycle length, 600 msec) with periods of sino-atrial block measuring 2,400 and 1,240 msec. Atrial rate further slowed so that the patient ultimately required a permanent demand pacemaker.

The case supports the theory of repetitive discharge from an ectopic atrial pacemaker to explain the mechanism producing atrial tachysystoles that simulate atrial flutter.
A Critical Appraisal of the Electrocardiographic Criteria for the Diagnosis of Left Ventricular Hypertrophy
Authors: ROMHILT DONALD W. , BOVE KEVIN E. , NORRIS ROBERT J. , CONYERS EMMETT , CONRADI SANDRA , ROWLANDS DAVID T. , SCOTT RALPH C.
Published: June 2012

Thirty-three different electrocardiographic criteria for left ventricular hypertrophy have been evaluated in 360 autopsied hearts utilizing a chamber dissection technic. One hundred and sixty hearts had left ventricular hypertrophy, and 200 hearts did not (146 of these were normal, and 54 had right ventricular hypertrophy).

The following five electrocardiographic criteria had a sensitivity of 56% but 10.5% to 14.5% false positives: S
v1
or S
v2
+R
v5
≥35 mm, S
v1
+R
v5
or R
v6
>30 mm, S
v1
, or S
v2
+ R
v5
or R
v6
>35 mm, S
v2
+R
v4
or R
v5
>35 mm, R+S>40 mm. A point-score system employing a combination of criteria had a sensitivity of 54%, but lowered the false positives to 3%. The best limb-lead criterion was R aV
L
>7.5 which had a sensitivity of 22.5% with only 3.5% false positives. The following criteria had no false positives, but the highest sensitivity was 19%: S
v1
≥24 mm, R aV
L
>11 mm, R
I
+S
III
>25 mm, R
I
>13 mm, R aV
L
>12 mm, R
I
>15 mm, R aV
L
>13 mm, and S aV
R
>14 mm. Overall the precordial lead criteria were considerably more sensitive but less specific than the limb lead criteria. Since only six of the 200 hearts without left ventricular hypertrophy were in persons less than 30 years of age, this is not the major explanation for the high incidence of false positives in the more sensitive voltage criteria. The problems of using voltage criteria alone and the need for new criteria and approaches to the electrocardiographic diagnosis of left ventricular hypertrophy are discussed.
Simultaneous Hypoglycemia and Acute Congestive Heart Failure
Authors: BENZING GEORGE , SCHUBERT WILLIAM , HUG GEORGE , KAPLAN SAMUEL
Published: June 2012

Acute congestive cardiac failure and hypoglycemia were observed simultaneously in 27 patients with underlying heart disease. Seventeen of this group had the hypoplastic left heart syndrome, two had transposition of the great vessels, and four had hypoglycemia postoperatively. Liver biopsy in four patients revealed a marked reduction of hepatic glycogen both biochemically and electron microscopically but normal phosphorylase and glucose-6-phosphatase activity. Reduction of their dietary intake and gastrointestinal malabsorption caused by congestive cardiac failure are suggested as possible mechanisms for the observed hepatic glycogen depletion. Constant intravenous infusion of glucose is the method of choice for the treatment of patients with acute congestive cardiac failure and hypoglycemia rather than epinephrine or glucagon. Five patients recovered sufficiently following treatment of hypoglycemia and acute cardiac failure to be discharged from the hospital.
Ventricular Echo Beats in the Human Heart Elicited by Induced Ventricular Premature Beats
Authors: SCHUILENBURG R. M. , DURRER D.
Published: June 2012

In three patients, all having as their only hemodynamic abnormality an elevated cardiac index at rest, ventricular echo beats could be elicited by ventricular premature beats induced during regular driving of the ventricle. The occurrence of ventricular echo beats was in each case limited to a small delay-range of the premature beat. Retardation of retrograde conduction of the premature ventricular impulse to the atria appeared to be a necessary condition for the initiation of the echo phenomenon.

One of the patients had retardation of antegrade A-V conduction of sinus and premature atrial beats. Atrial echo beats could be elicited in this case.

The genesis of the ventricular echo phenomenon in these cases could be explained by the dual conducting system theory.
Hemodynamic and Body Composition Changes Following Bilateral Nephrectomy in Chronic Renal Failure
Authors: HAMPERS CONSTANTINE L. , ZOLLINGER ROBERT M. , SKILLMAN JOHN J. , GUMPERT J. ROBERT W. , BAILEY GEORGE L. , MERRILL JOHN P.
Published: June 2012

Six patients with severe chronic renal failure and hypertension were evaluated before and again 1 and 4 months following bilateral nephrectomy while being maintained with regular hemodialysis. Hemodynamic function and body composition were measured by isotope dilution with each study. The mean femoral artery blood pressure (B.P.) of 142 mm Hg fell to 136 mm Hg (
P
,
ns
) at 1 month and to 120 mm Hg at 4 months (
P
< 0.005). This was mainly reflected in a drop in mean diastolic pressure of 13 mm Hg at 4 months (
P
<0.025). Total peripheral resistance tended to decrease, whereas, cardiac index was unchanged. Four months after nephrectomy, however, ability to raise both cardiac output and mean B.P. with standardized exercise had increased (
P
<0.005).

Changes in exchangeable Na
+
, K
+
, extracellular fluid, and total body water did not correlate with the change in B.P. Plasma volume showed a slight tendency to fall with the decrease in mean B.P. after nephrectomy despite constant body weight (
P
<0.1). It is concluded that bilateral nephrectomy has a salutary effect on the hypertension of chronic renal failure (CRF), that this effect may not be immediately apparent, and that the fall in B.P. is independent of marked changes in extracellular fluid and exchangeable Na
+
and plasma volume.
Progressive Muscular Dystrophy
Authors: DEMANY MARTIAL A. , ZIMMERMAN HENRY A.
Published: June 2012

This paper describes the case of a young man with progressive muscular dystrophy who had supraventricular arrhythmias and intractable congestive failure. Hemodynamic studies and left cineventriculographic findings were compatible with a diagnosis of severe left ventricular failure.

Coronary cinearteriography showed an abrupt ending of the artery to the sino-atrial node. At necropsy, a noninflammatory degeneration was found in this particular vessel. The pathogenesis of the cardiac arrhythmias seen in this condition is discussed in the light of these cineangiographic and histopathologic observations.
The Effect of Acute Digitalization on the Hemodynamic Response to Exercise in Coronary Artery Disease
Authors: PARKER JOHN O. , WEST ROXROY O. , LEDWICH J. RODNEY , DI GIORGI SALVATORE
Published: June 2012

Hemodynamic observations are made at rest and during exercise before and following the administration of 0.5 mg of ouabain in patients with coronary artery disease and in normal subjects. Patients with coronary artery disease and exertional angina showed evidence of reversible cardiac failure during exercise. The patients with coronary artery disease who did not have angina and the normal subjects had normal hemodynamic responses to exercise. Acute digitalization did not prevent angina in any of the symptomatic patients, although there was hemodynamic evidence of improved ventricular performance. In the patients with coronary disease without angina minor hemodynamic changes at rest and during exercise were suggestive of improved left ventricular function.
Left Heart Hemodynamics During Angina Pectoris Induced by Atrial Pacing
Authors: LINHART JOSEPH W. , HILDNER FRANK J. , BAROLD S. SERGE , LISTER JOHN W. , SAMET PHILIP
Published: June 2012

In order to determine the associated hemodynamic events, angina pectoris was induced by an atrial pacing technic. In all patients developing angina pectoris, ischemic changes were noted electrocardiographically. The hemodynamic findings were variable: in some patients no changes were noted; in others, significant increases in cardiac output, left ventricular end-diastolic pressures (LVEDP), and femoral arterial and pulmonary arterial pressures occurred. These changes suggest that, initially, ischemia produces a decrease in myocardial compliance and this may also be associated with enhanced sympathetic nervous system activity. Myocardial failure may subsequently ensue, however. The administration of nitroglycerin, during angina at a fixed rapid heart rate, resulted in a reduction in LVEDP and cardiac work. Chest pain was always relieved following these hemodynamic changes, indicating a dependence upon these changes for the effectiveness of nitroglycerin.
Long-Term Pervenous Atrial Pacing
Authors: KASTOR JOHN A. , DESANCTIS ROMAN W. , LEINBACH ROBERT C. , HARTHORNE J. WARREN , WOLFSON IRVING N.
Published: June 2012

Long-term pervenous right atrial pacing has been used in five patients with intact atrioventricular (A-V) conduction for the treatment of refractory ventricular arrhythmias in two subjects and marked sinus bradycardia in three, two of whom also had paroxysmal supraventricular arrhythmias. The pervenous method was used to avoid a thoracotomy, and atrial pacing was chosen over ventricular pacing to preserve the normal A-V contraction sequence. Reliable atrial pacing was established in four cases, but one patient required ultimate conversion to a ventricular system because of irregular atrial capture. The most constant pacing was achieved by using a curved electrode with the tip positioned in the right atrial appendage.
Left Atrial Transport in Mitral Stenosis
Authors: HEIDENREICH FRED P. , THOMPSON MARK E. , SHAVER JAMES A. , LEONARD JAMES J.
Published: June 2012

Active left atrial transport was examined acutely in five patients with mitral stenosis and sinus rhythm. To observe the effect of active left atrial contraction on subsequent left ventricular output, the timing of atrial contraction with respect to ventricular contraction was varied. Atrioventricular (A-V) dissociation produced by right ventricular pacing was used to change continually the relationship of left atrial (LA) to left ventricular (LV) contraction. Measurements of each beat included mitral valve gradient, left ventricular ejection time (LVET), and left ventricular peak-systolic pressure (LVPSP). The diastolic gradient was used to calculate diastolic flow per beat after the area of the stenotic mitral orifice had been previously determined. Calculated diastolic flow increased significantly (24%) as did the parameters of left ventricular output, LVPSP and LVET (
P
< 0.005 for both), when atrial contraction was optimally timed. Cumulative effects were observed when a series of well-placed or poorly placed atrial contractions occurred. The method documents change in LV output which depends on appropriate timing of LA contraction that may not have been seen with a steady-state approach.
Plasma Renin Activity in End-Stage Kidney Disease
Authors: GUTKIN MICHAEL , LEVINSON GILBERT E. , KING ANTHONY S. , LASKER NORMAN
Published: June 2012

Plasma renin activity, fluid and electrolyte balance, and hemodynamic conditions were measured in seven hypertensive patients with end-stage renal disease before and after five exchanges of peritoneal dialytic fluids which removed large amounts of water and sodium, sodium but little water, and little water and sodium, respectively. The subjects had normal plasma renin activity, severe anemia, high cardiac output, high total peripheral resistance, and elevated blood volume. Plasma renin activity rose with large losses of sodium and water but changed slightly when large amounts of sodium with little water or small amounts of sodium and water were removed. Plasma renin activity prior to dialysis did not correlate with mean arterial pressure, blood volume, cardiac index, total peripheral resistance, or serum sodium concentration. Change in plasma renin activity with dialysis correlated inversely with change in mean arterial pressure, water balance, and change in cardiac output, and directly with change in total peripheral resistance and change in serum sodium concentration. There was no correlation with change in blood volume or sodium balance.
Childhood Leukemic Heart Disease
Authors: SUMNERS J. E. , JOHNSON W. W. , AINGER L. E.
Published: June 2012

One hundred sixteen hearts of children dying with leukemia during the 5-year period of 1962 to 1967 were examined at necropsy. Forty-four per cent of the patients had at least one focus of leukemic infiltration, a slightly higher incidence than previously reported. The evidence suggests that peripheral leukocyte count, type of leukemia, and length of survival are factors that influence cardiac infiltration. Increased survival time due to improved therapy may explain the increase in percentage of hearts with leukemic infiltration. Electrocardiographic patterns, in general, were found, as previously reported, to be nonspecific for leukemic myocardial infiltration.

Cardiac hypertrophy of significant degree was found in 33 of 99 hearts evaluated for this aspect. Anemia, intrinsic to leukemia, is proposed as the principal factor responsible for this hypertrophy inasmuch as all possible alternate mechanisms were excluded and since previous clinical as well as experimental animal studies clearly have shown that chronic anemia frequently results in cardiac hypertrophy regardless of the etiology of the anemia.
Primary Pulmonary Hypertension in a Child
Authors: RAO B. N. SATYANARAYANA , MOLLER JAMES H. , EDWARDS JESSE E.
Published: June 2012

Clinical, pharmacologic, and pathologic findings presented are those in a 12-year-old boy with primary pulmonary hypertension associated with medial hypertrophy of the pulmonary muscular arteries and arterioles.

Intrapulmonary arterial administration of acetylcholine, tolazoline (Priscoline), or isoproterenol resulted in a fall in pulmonary vascular resistance and pressure.

Perforation of the right ventricle by an indwelling catheter terminated studies on the results of long-term intrapulmonary arterial administration of drugs shown to be effective.
The Ejection Click of Valvular Pulmonic Stenosis
Authors: HULTGREN HERBERT N. , REEVE RICHARD , COHN KEITH , MCLEOD RIMA
Published: June 2012

Ten patients with valvular pulmonic stenosis were studied by simultaneous external phonocardiograms and intracardiac pressure recordings during successive respiratory cycles to examine the mechanism of the respiratory variation in the ejection click. Selective cineangiograms were performed in four. During inspiration right ventricular end-diastolic pressure (RVEDP) exceeded the pressure in the pulmonary artery (+2.7 mm) and no ejection click was recorded. During expiration RVEDP was lower than the pressure in the pulmonary artery (-3.6 mm) and a click was recorded. The click was present throughout the respiratory cycle when pulmonary artery diastolic pressure consistently exceeded RVEDP. Clicks were associated with sudden "doming" of the valve demonstated by cineangiography. These data support the valvular origin of the ejection click in pulmonic stenosis and provide the following explanation for the respiratory variation: Inspiratory increase in venous return causes the valve leaflets to move to an open or "domed" position. Ventricular systole at this time produces no sound since there is no slack. With expiration pulmonary artery pressure exceeds RVEDP. Ventricular systole at this time produces an opening motion of the closed, slack leaflets. The click occurs when the opening motion is suddenly checked.
Arterial Hypoxemia Following Acute Myocardial Infarction
Authors: VALENCIA A. , BURGESS J. H.
Published: June 2012

Arterial hypoxemia was common in 53 patients following acute myocardial infarction. It was most marked in patients with evidence of left ventricular failure. Arterial oxygen tension, however, was reduced in many of the patients who were without evidence of failure.

An increase in arterial oxygen tension following three deep breaths suggested maldistribution of ventilation. Right-to-left shunting of blood was demonstrated by 100% oxygen studies. There was a significant correlation between reduced arterial oxygen tension and low pulmonary diffusing capacity, but a poor correlation between the former and a low cardiac index. We suggest that the hypoxemia following acute myocardial infarction is the result of abnormalities in small airways as well as of vascular congestion in the lungs.

The patients with the lowest arterial oxygen tension at the time of study subsequently had more marked arrhythmias and a higher mortality rate.
Hypovolemia in Shock Due to Acute Myocardial Infarction
Authors: LOEB HENRY S. , PIETRAS RAYMOND J. , TOBIN JOHN R. , GUNNAR ROLF M.
Published: June 2012

Twelve patients with the clinical features of shock following acute myocardial infarction were treated with low molecular weight dextran (LMWD) as a plasma volume expander. Two of the patients had elevated central venous pressures (CVP), and neither responded favorably to plasma volume expansion. The remaining 10 patients had CVPs under 7 mm Hg prior to dextran infusion; five survived. Each survivor responded favorably to dextran infusion manifested by an increase in arterial pressure and cardiac index. The average increase in CVP in these patients was 1.0 mm Hg per 100 ml of dextran infused. The other five patients died either without recovering from shock or in chronic cardiac failure. These patients failed to show a significant increase in arterial pressure or cardiac index after dextran infusion; CVP increased by an average of 1.9 mm Hg per 100 ml infused. Hypovolemia must be considered in all patients in whom clinical evidence of shock develops as a complication of acute myocardial infarction, and if the CVP is normal or low, plasma volume expansion should be undertaken with caution. Increase in arterial pressure and evidence of improved cardiac index with little rise in CVP indicate a good response to the infusion and excellent prognosis for survival.
Large Right Atrial Thrombi Surrounding Permanent Transvenous Pacemakers
Authors: LONDON ANTHONY R. , RUNGE PETER J. , BALSAM RICHARD F. , BISHOP MONICA B. , BOUSVAROS GEORGE
Published: June 2012

Transvenous pacemakers offer advantages but may also lead to complications not seen with transthoracic pacemakers. We have seen two patients in whom at autopsy large right atrial thrombi were found around the catheter. The first patient had signs of increasing right heart failure and oliguria and died 48 hours after implantation of the pacemaker, which functioned normally throughout. At autopsy 80% of the right atrium was filled by a thrombus. This thrombus had caused inadequate filling of the right atrium and seemed responsible for the deterioration and death of the patient. The second patient died suddenly 2 months after insertion of the pacemaker after suprapubic prostatectomy. At autopsy a well-organized thrombus encircled the catheter between the junction of the azygos vein and the superior vena cava to the tricuspid valve. The thrombus may have caused signs of right heart failure before death. Since right atrial thrombi may be detected by angiography and treated by surgery, it is important to be aware of this rare complication of transvenous pacing.
Intrapericardial Cyst Formation in Constrictive Pericarditis Simulating Tricuspid Stenosis
Authors: PITT AUBREY , CUTFORTH ROBERT H. , BENDER HARVEY W. , HUMPHRIES J. O'NEAL , STIRLING GEORGE R. , CRILEY J. MICHAEL , ROSS RICHARD S.
Published: June 2012

Two cases of constrictive pericarditis with intrapericardial cyst formation are presented. In each, a tricuspid diastolic murmur was present, and confirmation of a tricuspid valve gradient was obtained at cardiac catheterization. Angiographic studies revealed that the tricuspid valves were distorted by the cysts. In both patients, surgical excision was successfully achieved.

In case 1 a blood-containing cyst was found, the etiology of which is obscure. Case 2 was associated with rheumatoid arthritis, and the compression resulted from a chronic abscess that probably arose at a previous pericardiectomy.
A Study of the Human Heart as a Multiple Dipole Electrical Source
Authors: HOLT JOHN H. , BARNARD ANTHONY C. L. , LYNN M. STUART , SVENDSEN PEDER
Published: June 2012

A model for the electrical activity of the heart during depolarization, in which the ventricles were represented by 12 dipoles and the thorax by an inhomogeneous conductor, was evaluated. Potentials measured at 126 locations on the thoracic surface were used to determine the dipole strengths as a function of time for 58 normal sedentary subjects. Most of the dipole strengths had the form of a single pulse in time, the dipole onset sequence being consistent with the depolarization sequence found by others. Dipole activities (DA), obtained for each dipole by time integration of its strength, varied considerably between subjects. However, much of this variation arose from a systematic decrease of DAs with age. The separate DAs were summed to obtain the DAs of the septum and left and right ventricular free walls. The proportions of the summed DAs agreed with the cardiac component weights found by others. When the variation with the subject's age was removed, the total DA fluctuated by ±13% (standard deviation of the mean) in this series.
A Study of the Human Heart as a Multiple Dipole Electrical Source
Authors: HOLT JOHN H. , BARNARD ANTHONY C. L. , LYNN M. STUART
Published: June 2012

Using the method previously described, the time-varying strengths of 12 dipoles (representing the depolarization of the ventricles) were calculated from body surface potential measurements. Dipole activities (DA) were obtained for each dipole by time integration of its strength.

Seventy-two patients with angiographically determined left ventricular muscle weight (LVMW) were studied. Fifty-two of 53 patients with increased LVMW had increased DA in the left ventricle and septum (LVSDA). Thus, diagnostic sensitivity was 98%. Sixteen of 19 patients with normal LVMW had normal LVSDA (specificity, 84%). The correlation between LVSDA and LVMW was r
2
=86%, and the standard error of the LVMW estimate (
see
) was±49 g. A subgroup with pure left ventricular hypertrophy (LVH) consisting of 27 patients over 25 years of age with isolated aortic valve disease was studied separately. The correlation between LVSDA and LVMW was r
2
=92% and
see
was ±31 g. After correcting for the uncertainty in the angiographic LVMW measurements, the
see
for the complete group was reduced to ±37 g.

The diagnosis and quantitation of LVH with this method was considerably better than with conventional electrocardiography or vectorcardiography.
Plasma Renin Activity in Patients with Coarctation of the Aorta
Authors: WERNING CLAUS , SCHÖNBECK MANFRED , WEIDMANN PETER , BAUMANN KLAUS , GYSLING ETZEL , WIRZ PIERRE , SIEGENTHALER WALTER
Published: June 2012

In 10 patients with coarctation of the aorta, plasma renin activity was measured after recumbency and orthostatism in peripheral venous blood and, in some cases, in renal venous blood also. In nine of these patients, basic plasma renin values and those obtained under stimulatory conditions lay within normal range, and only in one patient were the values elevated. However, since this patient displayed the lowest gradient of mean arterial blood pressure proximal and distal to the stenosis, it can be regarded as improbable that the elevation in plasma renin activity was caused by the coarctation. Plasma renin activity in the renal venous blood of both kidneys, which was measured in three patients, showed no elevation.

On the basis of observations of other authors and of our own studies it can be concluded that the kidneys can contribute to the development of prestenotic hypertension in acute constriction of the aorta in experiments with animals, but in chronic coarctation in animals or in man the humoral or renal theory has no importance to the pathogenesis of hypertension.
Potential Improvements in Means of Evaluation of Acute Myocardial Infarction
Authors: Friedberg Charles K. , Harvey W. Proctor , GOLDSCHLAGER NORA , RAVENS KURT , LEB GEORG , COWAN CHARLES , BING RICHARD J.
Published: June 2012

Effective capillary blood flow (ECF) through the myocardium was studied after experimentally produced myocardial infarction in 33 dogs, and after clinical acute myocardial infarction in nine human subjects. In dogs, ECF as measured by Rubidium-86, was compared to terminal vascular capacity (TVC) as measured by I-131 albumin in infarcted and noninfarcted portions of the myocardium. In man, ECF was determined from the myocardial uptake of Rubidium-84 by the double coincidence counting system. A discrepancy between ECF and TVC in animals became apparent by the tenth day after infarction, at which time TVC had attained control levels, whereas ECF had not; 2 months later, ECF was still 24% less than control. Studies in man demonstrated a significant decrease in ECF within 4 days of infarction; the low flow persisted in one patient 6 weeks after the initial injury. Low ECF in patients was present despite the insignificant changes in cardiac and stroke indices, and in mean aortic pressure. It is thought that the low values for ECF after acute myocardial infarction might reflect alterations in cellular metabolism leading to interference with tissue uptake of rubidium.

The discussion that followed this paper appears after the paper by Dr. Richard Gorlin.
Effects of Acidosis on the Performance and Metabolism of the Anoxic Heart
Authors: GELET THEODORE R. , ALTSCHULD RUTH A. , WEISSLER ARNOLD M.
Published: June 2012

The present studies on the isolated rat heart perfused at constant rate (10 ml per minute) with 5% albumin in KRB were designed to investigate the influence of increased extracellular H+ ion on the pacemaker and contractile performance and the anaerobic metabolism of the anoxic heart. During anoxia, (96% N
2
, 4% CO
2
) at pH 7.4 in the presence of anaerobic substrate (glucose 200 mg/100 ml) the isolated heart performed spontaneously for 30 minutes. During this period there was active anaerobic lactate production (0.84 mM/30 min/gm of protein), whereas the myocardial content of ATP and total adenine nucleotides was significantly reduced when compared to aerobic control levels. Diminution in anoxic perfusate to pH 7.0, accomplished by addition of HCl, resulted in a significant depression of cardiac pacemaker activity and left ventricular contractile performance unassociated with a diminution in myocardial anaerobic lactate production, ATP, or total nucleotide content when compared to pH 7.4. During anoxia at pH 6.6 there was a marked decrement in cardiac pacemaker activity and ventricular performance, associated with slight diminution in anaerobic lactate production, ATP, and total nucleotide content of the myocardium when compared to pH 7.4. The data demonstrate that the decrement in function of the anoxic heart imposed by increasing extracellular hydrogen ion concentration to pH 7.0 does not primarily involve suppression of glycolytic activity. Only at pH 6.6, when cardiac performance is markedly suppressed, could evidence for diminished anaerobic glycolysis be elicited. These observations are consistent with the thesis that increased hydrogen ion concentration dominantly affects the energy utilization phase of cardiac metabolism.
Results of Repair of Tetralogy of Fallot
Authors: GOTSMAN M. S. , BECK W. , BARNARD C. N. , O'DONOVAN T. G. , SCHRIRE V.
Published: June 2012

One hundred and forty-six patients had radical operations for tetralogy of Fallot. In the early phase vertical ventriculotomy was used, often with extensive reconstruction of the outflow tract. In the late phase, transverse ventriculotomy was introduced and fewer outflow tract patches were inserted. The overall mortality (operative and late) was 10% to 13% in the first phase and 7% in the second phase.

Ninety-one patients were investigated by cardiac catheterization 1 year after surgery; 21 were virtually cured, four had residual outflow tract gradients of more than 50 mm Hg, and 12 had severe pulmonary incompetence. Six had a residual ventricular septal defect, and three had associated lesions. Pulmonary incompetence occurred in three patients who had infundibular resection only; otherwise it was associated with pulmonary valvulotomy and was more severe if an outflow tract patch was carried across the pulmonary valve ring.

Seven patients were recatheterized 5 years after the first postoperative study. The hemodynamics did not alter.

Right ventricular angiocardiography in 32 patients showed that half the patients after infundibular resection only showed a noncontractile portion of the outflow tract, and patients with a patch had an inert anterior wall of the right ventricle. A patch carried across the valve ring reestablished an inert but adequate conduit.
The Effect of Glucagon on the Coronary Circulation in Man
Authors: GOLDSCHLAGER NORA , ROBIN ERWIN , COWAN CHARLES M. , LEB GEORG , BING RICHARD J.
Published: June 2012

Glucagon, 300 µg/ minute, was infused intravenously over 15 minutes in 27 subjects. The patients were divided into three groups: group I, patients without heart disease; group II, patients with arteriosclerotic heart disease; and group III, patients with congestive heart failure. Hemodynamic measurements included observations on myocardial blood flow using bolus injections of
84
rubidium and a coincidence counting technic. Myocardial oxygen consumption was determined after coronary sinus intubation in nine of the 27 patients. Significant increases were noted in heart rate, mean arterial pressure, tension-time index/minute and left ventricular work. Myocardial blood flow increased significantly while myocardial oxygen extraction remained constant suggesting that the augmentation in blood flow was sufficient to meet the increased myocardial demands for oxygen. The effects of glucagon on the coronary circulation resemble that of isoproterenol rather than norepinephrine without, however, leading to the production of arrhythmias seen with these catecholamines.
The Effects of Propranolol on Cardiac Conduction
Authors: BERKOWITZ WALTER D. , WIT ANDREW L. , LAU SUN H. , STEINER CHARLES , DAMATO ANTHONY N.
Published: June 2012

The effects of propranolol, 0.1 mg/kg given intravenously, on atrioventricular (A-V) conduction and intraventricular (IV) conduction were studied in eight patients. Atrial pacing was used to control the heart rate. His bundle electrograms were recorded, and the interval from the pacing impulse to the His bundle electrogram (P-H interval) was used as a measure of A-V conduction and the interval from the His bundle electrogram to the S wave (H-S interval) was used as a measure of intraventricular conduction. Propranolol significantly prolonged the P-H interval in every patient at all paced heart rates, and it had no effect on the H-S interval. In two patients propranolol prolonged the effective refractory period of the atrioventricular conducting tissue.

In four dogs during His bundle pacing, propranolol (4 mg/kg iv) had no effect on intraventricular conduction as measured from the His bundle pacing spike to S wave (H-S interval). In two dogs with prolonged H-S intervals secondary to toxic doses of digitalis and procainamide, propranolol had no effect on IV conduction. It is concluded that propranolol prolongs A-V conduction and has no effect on IV conduction when administered to patients in clinically effective dosages. Propranolol's effects on cardiac conduction can be explained on the basis of its capacity to produce beta-adrenergic blockade.
Observations on the Regulation of Cerebral Blood Flow in Complete Heart Block
Authors: SHAPIRO WILLIAM , CHAWLA N. P. S.
Published: June 2012

The simultaneous effects of right ventricular pacing on cerebral blood flow (CBF) and cardiac function in complete heart block have not been reported. Catheters in the jugular bulb, right ventricle, and pulmonary and brachial arteries of five patients, aged 49 to 78 years, allowed studies at initial rates of 30 to 40 and during the tenth minute of pacing at 60, 70, 90, and 100 per minute. Mean initial cardiac output (CO) was 2.8 L per minute and increased 29% to 3.6 at a rate of 60 per minute (
P
<0.01). Simultaneous mean control CBF was also low, but rose to 118% of control with pacing (
P
<0.05). Systemic, cerebral, and pulmonary vascular resistances declined with these increases in flow as the elevated mean venous and arterial pressures remained stable. Mean arterial oxygen and carbon dioxide tensions and pH were normal at all rates. The parameters measured were not materially altered by pacing at rates above 60 per minute. The changes in CBF were well correlated with those of CO (r=0.81,
P
<0.01) and unrelated to simultaneous mean arterial or cerebral perfusion pressures. The alterations in CO were also unrelated to these pressures. The data clearly demonstrate a disturbance in CBF autoregulation, which may be a function of the low CO state.
Degeneration of the Cardiac Nerves in Chagas' Disease
Authors: MANÇO J. C. , GALLO L. , GODOY R. A. , FERNANDES R. G. , AMORIM D. S.
Published: June 2012

The Valsalva maneuver was performed by a series of eight patients with chronic Chagas' heart disease who had no current evidence nor past history of heart failure. The fact that all the patients showed recovery of arterial pressure during the latter portion of the period of increased airway pressure and exhibited significant overshoot in pressure in the post-straining period of the Valsalva maneuver strongly suggests that reflex activity of arteriolar tone was present. However, slowing of the heart rate was not found in association with the blood pressure overshoot in half of the patients. This abnormal response was observed only in patients in whom atropine sulfate failed to cause an increase in heart rate. These results are interpreted as a further indication of degeneration of autonomic nervous system controlling heart rate in chronic Chagas' heart disease.
Left Ventricular Diastolic Pressure Elevation Consequent to Pulmonary Stenosis
Authors: HERBERT WALTER H. , YELLIN EDWARD
Published: June 2012

Patients with mild pulmonary stenosis, predominant mitral stenosis, or aortic valvular disease were studied by standard catheterization technics to determine the effect of their lesions upon both the ipsilateral and contralateral ventricles.

The study suggested (1) that left heart lesions which produce an elevation of left ventricular end-diastolic pressure (LVEDP) do not necessarily cause an abnormal rise in diastolic pressure in the contralateral ventricle, (2) that eccentric right ventricular hypertrophy by definition without septal involvement may produce elevated right ventricular end-diastolic pressure without affecting LVEDP, and (3) that concentric right ventricular hypertrophy appears to effect an elevation in end-diastolic pressure in both the ipsilateral and contralateral ventricles.

Possible mechanisms related to the biventricular architecture are discussed.
Termination of Paroxysmal Junctional Tachycardia by Right Ventricular Stimulation
Authors: ZEFT HOWARD J. , MCGOWAN RONALD L.
Published: June 2012

This report documents the use of right ventricular stimulation in the termination of a rapid junctional tachycardia. The tachycardia developed in the background setting of heart block and bradycardia. Right ventricular stimulation was effective at 94/min, a rate considerably slower than that of the tachycardia. Analysis of pacemaker stimuli during the tachycardia defined ventricular refractory and excitable periods. Within the ventricular excitable period there was a critical time interval during which stimulation produced premature ventricular depolarization and abrupt termination of the tachycardia. These findings support the hypothesis that junctional tachycardias in the absence of the Wolf-Parkinson-White syndrome may be sustained by reentry mechanisms. Moreover, right ventricular stimulation may be a valuable therapeutic adjunct in the treatment of such tachycardias.
Localization of the Site of Myocardial Scarring in Man by High-Frequency Components
Authors: FLOWERS NANCY C. , HORAN LEO G. , TOLLESON W. J. , THOMAS J. R.
Published: June 2012

The increased incidence of high-frequency components (notching) in electrocardiographic (ECG) recordings previously has been related to coronary artery disease, primary myocardial disease, and biventricular enlargement.

This study included 130 subjects on whom autopsy permission was obtained, who had one or more sets of high-frequency, orthogonal ECG (XYZ) leads and direct-writing standard ECG leads recorded ante mortem. In each instance careful dissection of the heart was performed by two or more of the authors according to fixed protocol.

Correlations were made between the site of infarction and the occurrence of notching in specific high-frequency ECG leads. Postero-inferior infarctions tended to express themselves with a predominance of increased notching in the Y lead, while anterior infarction manifested dominantly in the X lead. This was true in intramural as well as transmural lesions.

The greatest value of notch recognition in diagnosing and localizing infarction appeared to be in subjects with normal sized hearts, with none of the classic ECG criteria for infarction, but who ultimately proved to have intramural scarring. In these subjects the increased incidence of notching clearly could not be attributed to biventricular enlargement, nor could the ECG diagnosis of infarction be arrived at by conventional criteria.
Reduction of Serum Cholesterol and Triglyceride Levels by the Combined Administration of Neomycin and Clofibrate
Authors: SAMUEL PAUL , HOLTZMAN CHARLES M. , MEILMAN EDWARD , SEKOWSKI IGNACY
Published: June 2012

The combined oral administration of neomycin (2 g daily) and clofibrate (2 g daily) reduced significantly serum cholesterol levels in 15 of 16 patients. Most of these patients had type II hypercholesterolemia and clinical evidence of arteriosclerosis. The combined regimen of the two drugs was more effective in reducing cholesterol levels in about one third of the patients than administration of either one of these drugs alone. The average decrease of serum cholesterol in these patients while on the combined regimen was 38% from the control values. Control serum triglyceride levels were normal in most patients, thus the effect of the drugs on triglycerides was moderate. No noteworthy side effects were encountered. It is felt that a trial of treatment by the combined administration of neomycin and clofibrate is justified in patients with type II hypercholesterolemia and arterioscleroisis who are resistant to other forms of treatment or to treatment by a single drug.
Double-Outlet Left Ventricle with an Intact Ventricular Septum
Authors: PAUL MILTON H. , MUSTER ALEXANDER J. , SINHA SACHCHIDA N. , COLE ROGER B. , VAN PRAAGH RICHARD
Published: June 2012

Clinical, laboratory, and anatomic findings were presented concerning the first clinically diagnosed and autopsy proved case of origin of both great arteries from the morphologically left ventricle.

The salient pathologic findings were: normally interrelated chambers (noninverted) in situs solitus; no ventricular septal defect; infundibular atresia; infundibulum related only to the right ventricle; absence of infundibular musculature beneath the great arteries, with aortic-mitral and pulmonary-mitral fibrous continuity; semilunar valves side by side, aortic to the right and pulmonary to the left, and at approximately the same height; thick-walled and small-chambered right ventricle with endocardial fibroelastosis of the apical half of the ventricle; hypertrophy and enlargement of both atria and of the left ventricle; absence of the left coronary ostium; and a fistula between the right ventricular apex and the anterior descending coronary artery.

The main developmental implications of this rare case appear to be as follows: (1) strong support is given for the differential conal growth hypothesis concerning the morphogenesis of great arterial interrelationships; (2) truncus arteriosus communis would appear to have atresia, not absence, of the subpulmonary infundibulum; (3) the truncal septum does extend a short distance below the semilunar valves; and (4) the conus arteriosus appears to be a separate cardiac segment, not part of the right ventricle and not part of the great artelies.
Impaired Function of Cloth-Covered Starr-Edwards Mitral Valve Prosthesis
Authors: CRAIGE ERNEST , HUTCHIN PETER , SUTTON RICHARD
Published: June 2012

Malfunction of a cloth-covered Starr-Edwards mitral valve prosthesis (6300 series) was suspected because of phonocardiographic abnormalities. A prolonged interval from aortic closure to opening of the mitral ball suggested an impediment to movement of the ball. This was confirmed by catheterization and cinefluorography. At autopsy the impaired ball movement was found to be due to thrombus buildup on the outflow face of the mitral valve orifice. It is suggested that frequent postoperative phonocardiographic observations may be useful in detecting malfunction of valvular prostheses.
Role of Renin in Acute Postural Homeostasis
Authors: OPARIL SUZANNE , VASSAUX CARLOS , SANDERS CHARLES A. , HABER EDGAR
Published: June 2012

Plasma renin activity has been measured by radioimmunoassay at frequent intervals after passive upright tilting and correlated with pulse and blood pressure in normotensive man. In the normal response to upright posture, renin activity in both peripheral and renal veins increases consistently within a few minutes. The renin rise lags behind the increase in pulse rate and diastolic blood pressure. Renin activity falls to base-line level soon after return to the horizontal position. In the 25% of normal subjects who develop vasovagal syncope after upright tilting, the increase in renin activity is smaller in magnitude and duration than in the normal response. Renin levels fall just before syncope appears and rise sharply after return to the horizontal position. Anephric patients are able to effect adequate postural adjustments even in the absence of renin activity.

This study indicates that the renin angiotensin system participates in the acute response to postural change in normal man and that it functions abnormally in vasovagal syncope.
The Influence of Hypertonic Saline Infusions Upon the Fractional Reabsorption of Urate and Other Ions in Normal and Hypertensive Man
Authors: CANNON PAUL J. , SVAHN DAVID S. , DEMARTINI FELIX E.
Published: June 2012

Renal hemodynamics and the excretion rates of six ions were studied in a group of 24 normotensive and hypertensive subjects during expansion of extracellular fluid volume (ECF) with intravenous infusions of hypertonic saline. In response to the 2.5% saline infusions arterial blood pressure did not change from control values, but glomerular filtration rate increased, and renal vascular resistance decreased.

Accompanying these hemodynamic alterations the urinary excretion rates of sodium, calcium, magnesium, potassium, chloride, and urate increased significantly. Net fractional reabsorption of the six ions fell significantly below control values. The induced changes in net Ca, Mg, K, Cl, and urate reabsorption in all the subjects were directly and significantly related to the simultaneous depression of Na reabsorption.

The data indicate that increased excretion and net tubular rejection of urate accompany depression of tubular sodium reabsorption during hypertonic saline infusions in normal and hypertensive man. The nonspecificity of depressed fractional ion reabsorption during the infusions is compatible with the hypothesis that physical forces which alter fluid uptake by peritubular capillaries determine to a significant extent the natriuretic response of the human nephron to hypertonic saline infusions. Alternatively, if a natriuretic hormone elicited by ECF volume expansion in man accounts for the depressed fractional Na reabsorption, the data imply that directly or indirectly this substance inhibits net fractional reabsorption of a variety of other ions.
Relationship Between Quantitated Precordial Movement and Left Ventricular Function
Authors: SUTTON GEORGE C. , PREWITT TAYLOR A. , CRAIGE ERNEST
Published: June 2012

The relationship between external records of precordial movement and ventricular function has been studied in 61 patients with various cardiac disorders by comparing the records of the apical impulse to the left ventricular volume. A significant correlation between external recordings and the volume data was found in patients with normal or increased ventricular volumes: Patients with a normal record in systole usually had normal end-diastolic and left ventricular stroke volumes; those with a hyperdynamic record in systole usually had an appropriate increase in stroke volume for increased end-diastolic volume; and those with sustained records usually had an increased end-diastolic volume without an appropriate increase in stroke volume, indicating poor myocardial function. Patients with a pressure-loaded left ventricle usually had a sustained record, but this appeared to be related to factors other than volume.

These studies demonstrate that records of the apical impulse may provide useful information about left ventricular function.