bluuebunny/crossref_metadata_2025 huggingface dataset:
Rheumatic Heart Disease Epidemiology
Authors: MORTON WILLIAM E. , WARNER ARTHUR L. , WEIL JOHN V. , SHMOCK CARLETON L. , SNYDER JOSEPH , LICHTY JOHN A.
Published: June 2012

After epidemiologic data had suggested the existence of a high-risk rheumatic fever (RF) region in Colorado, examination of 3,737 children in a careful prevalence study in that region, the San Luis Valley yielded 14 cases of rheumatic heart disease (RHD) for a prevalence rate of 3.7/1,000. This rate was significantly higher than the rate of 1.7/1,000 among Denver children of the same age screened by a similar method and followed for a similar period for ascertainment of diagnoses. Although the current high RHD risk in the San Luis Valley had been thought to be due to the relative impoverishment of this part of the state, the RHD and history-of-RF prevalence rates did not correlate with socioeconomic indices by county within the Valley as expected. An ethnic difference in RHD prevalence seen in Denver did not exist in the San Luis Valley, which led to speculation about (1) patterns of school attendance in small towns versus urban areas, and (2) the probability that the influence of poverty as an RHD-risk factor operates on a community rather than on a family or individual level.
The Effect of Pregnancy on the Murmurs of Mitral and Aortic Regurgitation
Authors: MARCUS FRANK I. , EWY GORDON A. , O'ROURKE ROBERT A. , WALSH BERNARD , BLEICH ALLAN C.
Published: June 2012

The effect of pregnancy on the intensity of murmurs of aortic and mitral regurgitation has not been reported previously. Twenty-five women with these murmurs, singly or in combination, were examined when pregnant as well as when not pregnant. During pregnancy the murmur of aortic regurgitation decreased in intensity or became inaudible in 10 patients, remained unchanged in four, and increased in one. The murmur of mitral regurgitation decreased in intensity or became inaudible in eight patients, became shorter in duration in two, was unchanged in three, and became louder in one. Three of the patients who did not show a decrease in intensity of the mitral or aortic regurgitation murmur and the patient whose murmurs increased during pregnancy had the appearance or persistence of systemic hypertension during pregnancy. Phenylephrine consistently increased the loudness of the murmurs, usually to the level present in the nonpregnant state. The diminished intensity of these murmurs may be related to the decrease in peripheral resistance known to occur during pregnancy. It is apparent that (1) aortic regurgitation or mitral regurgitation may be missed during pregnancy, since these murmurs may become inaudible, and (2) the severity of these cardiac lesions may be underestimated clinically because of a decrease in intensity of these murmurs during pregnancy. It is important to determine the existence of valvular heart disease, since endocarditis is a hazard during parturition, and prophylactic antibiotic therapy should be given to these patients.
Complications of Left Heart Angiography
Authors: BECKMANN CHARLES H. , DOOLEY BYRON
Published: June 2012

A study of 1,000 consecutive left heart cineangiocardiograms was made to determine the frequency of various complications. Ten per cent of angiographic procedures caused minor complications such as nausea, vomiting, transient arrhythmias, loss of pulse, or hives. Most of these complications were gone before the patient left the cardiac catheterization laboratory.

Major problems were associated with 3.1% of the angiograms performed. The majority involved either vessel thrombosis (1.2%) or cardiac complications such as arrhythmias, intramyocardial dye injection, or myocardial infarcts (1.4%). Femoral arterial thrombosis was especially frequent in patients with mitral valve disease and low cardiac index. The use of lidocaine-lubricated catheters, tape traction hemostasis, and Fogerty catheter clot removal virtually eliminated brachial arterial thromboses. This route is now used almost exclusively for left heart angiography at our institution.

Most cardiac complications resulted from open-end catheter angiography, especially through transseptal catheters. The frequency of major cardiac complications has decreased markedly since the regular use of closed-tip catheters via the brachial artery route was begun for left heart angiography.
Arterial Thrombus Formation During Clinical Percutaneous Catheterization
Authors: FORMANEK GUSTAVE , FRECH ROBERT S. , AMPLATZ KURT
Published: June 2012

Deposition of thrombotic material on catheters was observed following more than 50% of 93 diagnostic catheterizations. The incidence of deposition of thrombotic material on catheters remaining in the body for more than 1 day was 100%. Polyethylene and siliconized polyurethane catheters were less thrombogenic than Teflon end-occluded catheters.

A definite time relationship between the thrombus formation and the duration of the catheterization procedure was noted.

The growth of thrombi on the outside of catheters does not appear to be linear since catheters can remain in place for 10 days or more.

Postcatheterization thrombosis is believed to be due to thrombi stripped from the catheter by the arterial wall. The thrombus which originally encases the catheter will pile up at the puncture site as the catheter is withdrawn. The thrombus may remain attached at the puncture site or embolize peripherally.
Histological and Ultrastructural Studies on Preserved Hearts
Authors: FERRANS VICTOR J. , LEVITSKY SIDNEY , BUJA L. MAXIMILIAN , WILLIAMS WILLIS H. , MCINTOSH CHARLES L. , ROBERTS WILLIAM C.
Published: June 2012

Histological and ultrastructural studies were made on 17 excised canine hearts after 0 (control), 3, 14, 18, and 24 hours of preservation by perfusion with cold filtered plasma. These were correlated with function as measured by an isovolumetric balloon technique. Variations in structure and function were observed within each group of preserved hearts, but function and structure correlated well in individual hearts: when function was excellent, structure was excellent; when function was poor, changes in the sarcoplasmic reticulum and mitochondria were prominent. The presence of marked angulations in the mitochondrial cristae correlated with high dp/dt values. Interstitial edema was present in all preserved hearts. The three control hearts, one 3-hour heart, and two 14-hour hearts showed excellent morphology and function. Of the five 18-hour hearts, function and morphology were excellent in three and barely adequate in one; a severely damaged heart could not be defibrillated. Of the six 24-hour hearts, morphology and function were excellent in three and poor in two; one heart with diffuse mitochondrial damage could not be defibrillated. These studies demonstrate good morphological preservation of canine hearts for 24 hours.
Heterograft Replacement of the Mitral Valve: Clinical, Hemodynamic, and Pathological Features
Authors: KOUCHOUKOS NICHOLAS T. , KERR ALAN R. , SHEPPARD LOUIS C. , CEBALLOS RICARDO , KIRKLIN JOHN W.
Published: June 2012

Seventeen patients had replacement of their diseased mitral valves with formalin-fixed, mounted porcine heterografts over a ten-month period with no operative or postoperative mortality.

Hemodynamic studies early after operation indicate that patients with heterograft mitral valves behave no differently than patients who have had replacement of the mitral valve with ball valves. The early postoperative myocardial dysfunction present after mitral valve replacement is probably not related to the presence of a caged ball or other such device in the left ventricle. Late hemodynamic studies in two patients have shown complete competence of the valves and minimal mean diastolic and absent end-diastolic gradients at rest between the left atrium and left ventricle.

Six of the valves became incompetent and were removed from 2 to 11 months after operation. Histological study of these valves suggests that the development of incompetence in five of them was related to absorption of muscle beneath the right coronary cusp with retraction of the tissues supporting this cusp and subsequent avulsion of the adjacent tissues from the supporting frame.

The 11 patients whose valves remain competent are all clinically improved 6 to 15 months after operation. There have been no thromboembolic complications in any of the patients although long-term anticoagulation has not been used.

The failure of the aortic valve heterografts mounted on rigid frames in this series appears related to mechanical stress resulting from imperfect coaptation of the valve cusps, either from resorption of heterograft tissue or improper mounting. Further studies are necessary to clarify these observations.
Metabolic Assessment of Internal Mammary Artery Implantation in the Dog
Authors: KAISER GEORGE C. , BARNER HENDRICK B. , JELLINEK MAX , MUDD J. GERARD , HANLON C. ROLLINS
Published: June 2012

The metabolic and physiologic contributions of an implanted internal mammary artery have been assessed in five dogs 24 to 34 months following internal mammary artery implantation and concomitant ameroid constrictor application to coronary arteries. All implants were patent angiographically prior to evaluation by right heart bypass and continual autoanalyzer assessment of myocardial oxygen, pyruvate, and lactate extraction. Control internal mammary artery flow averaged 17.5 ml/100 g LV/min. Occlusion of the internal mammary artery failed significantly to alter myocardial extraction of oxygen, pyruvate and lactate or ventricular function, nor did these patent implants prevent significant changes in oxygen, pyruvate, and lactate extraction and ventricular function during and following occlusion of a remaining patent left coronary artery. In only one animal did internal mammary artery flow increase with left coronary artery occlusion, and this only transiently. These results indicate that demonstration of angiographic patency of an internal mammary artery implant does not necessarily indicate significant metabolic or functional contribution of this extracardiac blood supply to the heart.
Heart-Reactive Antibody: An Index of Cardiac Rejection in Human Heart Transplantation
Authors: ELLIS ROBERT J. , LILLEHEI C. WALTON , FISCHETTI VINCENT A. , ZABRISKIE JOHN B.
Published: June 2012

Indirect immunofluorescent techniques used for detection of heart-reactive antibody have been used in both human and experimental cardiac transplantation. Definite evidence is presented which demonstrates the presence of circulating heart-reactive antibody preceding clinical or laboratory evidence of cardiac rejection. In all patients who lived longer than one week and died of cardiac rejection, an increase in titers of heart-reactive antibody were present prior to obvious signs of rejection and death. Immunosuppressive therapy, both experimentally and clinically, has been demonstrated to alter the titer of circulating heart-reactive antibody. Much work is needed to clarify the significance of this heart-reactive antibody in the mechanism of rejection. However, the presence of heart-reactive antibody in patients after cardiac transplantation appears to be a valuable aid in monitoring cardiac rejection.
Catheterization of the Pulmonary Artery in Transposition of the Great Arteries
Authors: CELERMAJER JOHN M. , VENABLES ALEX W. , BOWDLER J. DENBY
Published: June 2012

A simple method of catheterization of the pulmonary artery in transposition of the great arteries with the use of a "floppy wire" and "J wire" is described. The method can also be used to enter the aorta from the left ventricle in cases in which there is an interatrial communication.
Total Excitation of the Isolated Human Heart
Authors: DURRER DIRK , VAN DAM R. TH. , FREUD G. E. , JANSE M. J. , MEIJLER F. L. , ARZBAECHER R. C.
Published: June 2012

To obtain information concerning the time course and instantaneous distribution of the excitatory process of the normal human heart, studies were made on isolated human hearts from seven individuals who died from various cerebral conditions, but who had no history of cardiac disease. Measurements were made from as many as 870 intramural terminals.

In the isolated human hearts three endocardial areas were synchronously excited 0 to 5 msec after the start of the left ventricular activity potential. These areas increased rapidly in size during the next 5 to 10 msec and became confluent in 15 to 20 msec. The left ventricular areas first excited were (1) high on the anterior paraseptal wall just below the attachment of the mitral valve; (2) central on the left surface of the interventricular septum and (3) posterior paraseptal about one third of the distance from apex to base. The last part of the left ventricle to be activated usually was the posterobasal area. Endocardial activation of the right ventricle was found to start near the insertion of the anterior papillary muscle 5 to 10 msec after onset of the left ventricular cavity potential. Septal activation started in the middle third of the left side of the interventricular septum, somewhat anteriorly, and at the lower third at the junction of the septum and posterior wall. The epicardial excitation pattern reflected the movements of the intramural excitation wave. Conduction velocity was determined in one heart by an appropriate stimulation technic. Atrial excitation, explored in two hearts, spread more or less according to concentric isochronic lines.

Control studies, carried out on five canine hearts, disclosed that the pattern of ventricular excitation did not change after isolation and perfusion. However, total excitation was completed earlier in the isolated heart, and conduction velocity increased.

Careful mapping illustrations are presented.
Observations on Atrioventricular Conduction in Patients with Bilateral Bundle-Branch Block
Authors: SCHUILENBURG R. M. , DURRER DIRK
Published: June 2012

Atrioventricular conduction was studied in three patients, each representing a different grade of bilateral bundle-branch block. His bundle activity was recorded by a catheter technic. Two of the three patients had experienced Adams-Stokes attacks.

The first patient had right bundle-branch block with left axis deviation at the time of catheterization. Increases in the atrial driving rate resulted in progressive lengthening of the A-H interval, the H-V interval remaining constant and within normal limits. Second degree A-V block occurred at atrial rates higher than 140/min. The site of this block was located above the His bundle. On no occasion was the impulse blocked distally to the His bundle.

The second patient had a Mobitz type II A-V block with complete left bundle-branch block and a prolonged P-R interval in the conducted beats. The block of the nonconducted beats could be located distal to the His bundle. H-V block occurred more frequently when the atrial rate was increased. Second degree A-H block occurred at rates above 140/min. At these rates interesting patterns were seen due to conduction impairment at two levels in the A-V conduction system.

The third patient presented with complete A-V block. The site of this block could be located at a level lower than the His bundle. A-H conduction studied with increases of atrial rate and with atrial premature beats seemed to be normal. There was evidence for the existence of retrograde V-A conduction in this patient.
The Pattern of Onset and Spontaneous Cessation of Atrial Fibrillation in Man
Authors: BENNETT MICHAEL A. , PENTECOST BRIAN L.
Published: June 2012

The atrial electrocardiogram was studied in eight patients who developed intermittent atrial fibrillation following myocardial infarction. Thirty-two episodes of onset of atrial fibrillation and 28 episodes of spontaneous cessation were observed. An atrial premature beat followed by atrial tachycardia of variable duration always preceded the onset of atrial fibrillation. Spontaneous cessation of atrial fibrillation was preceded by a change of atrial wave form which suggested slowing of an ectopic focus. The time lapse between the cessation of atrial fibrillation and the onset of sinus rhythm exceeded the subsequent sinus cycle length which suggested overdrive and suppression of the sinoatrial node during the period of atrial fibrillation.
Ultrasound Cardiography in Single Ventricle and the Hypoplastic Left and Right Heart Syndromes
Authors: CHESLER ELLIOT , JOFFE HYMIE S. , VECHT ROMEO , BECK WALTER , SCHRIRE VELVA
Published: June 2012

Seven cases of single ventricle, six cases of hypoplasia of the right heart (tricuspid atresia), and one case of hypoplasia of the left heart were investigated with reflected ultrasound. In hypoplasia of the right heart there was abnormal anterior movement of the mitral valve; in hypoplasia of the left heart, abnormal anterior movement of the tricuspid valve, and in single ventricle, similiar movement of the anterior component of a single valve. In one case of single ventricle, two separate valves were identified at different depths. In none of the cases could a ventricular septum separating two ventricular cavities be identified. Ultrasound cardiography may be particularly useful as a non-invasive preliminary investigation of infants with congenital heart disease. Failure to demonstrate a ventricular septum combined with the presence of a single atrioventricular valve moving abnormally far anteriorly may be an expression of marked hypoplasia of the left or right ventricles or an anatomically single ventricle with one valve.
Total Anomalous Pulmonary Venous Connection
Authors: GATHMAN GARY E. , NADAS ALEXANDER S.
Published: June 2012

Experience with 75 cases of proven total anomalous pulmonary venous connection without other significant cardiac malformations treated at the Children's Hospital Medical Center in Boston from January 1950 to June 1968 forms the basis of this report. Clinical observations of patients with this defect presenting in infancy are reviewed in depth, and the few patients presenting after 1 year of age are included to give a spectrum of this disease in the pediatric age group.

Chest x-rays and complete electrocardiograms were available in each case. Sixty-one patients had partial or complete cardiac catheterizations. The anatomic and physiologic data from these studies are presented, and the results of medical management are evaluated.

On the basis of the physiologic data, an approach to management is proposed which includes early operative intervention in those patients with pulmonary vascular obstruction. If pulmonary hypertension is present without vascular obstruction, medical management may be tried. If pulmonary hypertension is not present and particularly if there is a significant gradient across the right ventricular outflow tract, medical management appears to be the treatment of choice until operative intervention can be undertaken with less operative mortality.
Balloon Embolization During Atrial Septostomy
Authors: VOGEL JOHN H. K.
Published: June 2012

The case of an infant with complete transposition is presented. Embolization occurred from a balloon catheter used in performing a Rashkind septostomy.
Effects of Glucagon on Myocardial Metabolism in Patients With and Without Coronary Artery Disease
Authors: BOURASSA MARTIAL G. , EIBAR JOSÉ , CAMPEAU LUCIEN
Published: June 2012

The metabolic effects of glucagon on the heart were studied in subjects with and without coronary artery disease. In both groups, a moderate rise in the arterial glucose level occurred with practically unchanged glucose uptake by the myocardium. Myocardial oxygen extraction was also unchanged in both groups of subjects. In individuals with normal coronary arteries, myocardial extraction ratio of lactate was normal before and unchanged after glucagon administration. In patients with significant coronary artery disease, mean extraction ratio of lactate was very low before glucagon and increased markedly following its administration. Seven of 18 patients had production of lactate by the myocardium before glucagon, and this reverted to lactate extraction 5 min after glucagon administration. Left ventricular work index was found to increase more than indices of myocardial contractility and oxygen consumption, and improved aerobic lactate utilization during glucagon action may be partly related to the lower oxygen cost of work performance or improved cardiac efficiency. Arterial serum potassium level decreased in both groups of subjects after glucagon administration, with the appearance of a slightly negative potassium balance across the myocardium. The possible relationship of the cardiac inotropism induced by glucagon to intramyocardial ionic exchanges is discussed.
Sotalol-Induced Beta Blockade in Cardiac Patients
Authors: BROOKS HAROLD , BANAS JOHN , MEISTER STEVEN , SZUCS MURRILL , DALEN JAMES , DEXTER LEWIS
Published: June 2012

Sotalol (MJ 1999), a beta-adrenergic blocking agent found to have no significant intrinsic myocardial depressant effects, was administered intravenously to 20 patients with heart disease. Eight of the patients had clinical and hemodynamic evidence of chronic heart failure. Doses ranged from 0.2 to 0.6 mg/kg.

In all studies, heart rate decreased significantly, accompanied by comparable decreases in cardiac index and tension-time index. There were, however, no significant changes in stroke index, mean blood pressure, or left ventricular end-diastolic pressure—even in those patients with advanced heart failure, indicating that the changes noted were primarily rate-related and could not be ascribed to myocardial depression. To confirm this, further studies were performed in which heart rate was held constant by atrial pacing in normal and catecholamine-depleted dogs. Sotalol, at doses much higher than the minimal beta-blocking dose, did not change stroke index, blood pressure, left ventricular end-diastolic pressure, or estimated maximal velocity of isotonic shortening (V
max
), confirming that myocardial contractility was unaffected.

It is concluded that sotalol-induced beta blockade had no observable myocardial depressant action in dogs or adverse hemodynamic effects in cardiac patients, even when advanced chronic heart failure was present.
Acute Hemodynamic Effects of Red Cell Volume Reduction in Polycythemia of Cyanotic Congenital Heart Disease
Authors: ROSENTHAL AMNON , NATHAN DAVID G. , MARTY ALAN T. , BUTTON LAWRENCE N. , MIETTINEN OLLI S. , NADAS ALEXANDER S.
Published: June 2012

Acute reduction in red cell volume (RCV) without significant alterations of blood volume in 22 patients with severe polycythemia secondary to cyanotic congenital heart disease resulted in a decrease in peripheral vascular resistance and an increase in stroke volume, systemic blood flow (SBF), and systemic oxygen transport. These changes are probably related to the decreased blood viscosity and yield shear stress associated with lower red cell concentrations. Hypervolemia in hypoxic polycythemia should be maintained in order to sustain an adequate SBF. In contrast to acute phlebotomy which may be expected to decrease blood oxygen content and SBF, the replacement of whole blood with plasma or 5% albumin is shown to result in an increased systemic blood flow and oxygen delivery.
Heart Sounds in Patients with Homograft Replacement of the Mitral Valve
Authors: GIANELLY RALPH E. , POPP RICHARD L. , HULTGREN HERBERT N.
Published: June 2012

Phonocardiographic, hemodynamic, angiographic, and cardiac echographic studies have been performed on 11 patients whose diseased mitral valves have been replaced by a supported aortic valve homograft. The chordae tendineae and papillary muscles were removed in all patients during the operation. Apical first heart sounds of normal intensity were present in all patients after surgery. Nine patients exhibited splitting of the first sound. The initial component occurred when bulging of the homograft leaflets into the atrium was suddenly checked after the onset of ventricular systole. The second component occurred at the onset of rapid annular motion toward the base. Both sounds thus appear to originate in the homograft valve. Four patients had third heart sounds of left ventricular origin. The homograft leaflets were open and demonstrated no abrupt motion at the time of the third sound. It is evident that the third heart sound may occur in the absence of chordae tendineae and papillary muscles.
Intrarenal Distribution of Blood Flow in Man
Authors: TAKEUCHI JUGORO , ISHIKAWA ISAO , INASAKA TOHRU , SAKAI SHUICHIRO , SHINODA AKIRA , TAKADA AKIRA , HAMADA NOBORU
Published: June 2012

To measure blood flow through fast and slow pathways of the kidney separately, a new method of analyzing dye-dilution curves was devised. Twenty-five patients with hypertension or renal disease were selected for study. Indocyanine green was injected into one renal artery and dye-dilution curves were recorded in blood from the ipsilateral renal vein, using a densitometer. Recirculation effect was eliminated by the curve obtained from the contralateral renal vein. For analyzing the dyedilution curves, a new mathematical model and an iterative least squares method of fitting the curve using a digital computer were employed. Basic assumption for the model was that the transit time of each molecule of the dye through fast and slow pathways was a random variable and followed a log-normal distribution. The fast flow measured by the new method was significantly decreased in 11 patients with azotemia compared with that in 14 without azotemia, while changes in slow flow were not significant. Consequently, the ratio of the slow flow to the total flow was increased in renal failure.
Catheter Recording and Validation of Left Bundle-Branch Potentials in Intact Dogs
Authors: LAU SUN H. , BOBB GUSTAVUS A. , DAMATO ANTHONY N.
Published: June 2012

The left bundle-branch potential (LB), as well as His bundle (H) and atrioventricular nodal (N) potentials, were recorded in intact dogs by using a tripolar electrode catheter positioned in the left ventricle. Simultaneous recordings of H and right bundle-branch (RB) activity from the right endocardial surface were also made. The LB potential was less rapid than the RB potential, but both occurred almost simultaneously after the H potential. Atrial premature stimulation was used to induce aberrant ventricular conduction (right or left bundle-branch block) and to verify the recorded bundle-branch potentials. During LBBB the LB potential became absent, while during RBBB the RB potential became absent, indicating blockade or delay of conduction. Incomplete LBBB showed a delay in the LB potential. Initial spontaneous activity in the left bundle branch or its Purkinje system was manifested by a premature beat which resembled a RBBB pattern electrocardiographically. Spontaneous activity in the right bundle branch or its terminal Purkinje system manifested as a LBBB pattern. The recording of bundle-branch potentials by this technic may enable investigators to study further the cardiac electrical phenomena in intact animals or in man.
The Pathogenesis of Atrioventricular Block in Coronary Disease
Authors: LEV MAURICE , KINARE SUMAN G. , PICK ALFRED
Published: June 2012

The hypothesis that the pathogenesis of acute and chronic atrioventricular (A-V) block in coronary disease is different is investigated. The conduction systems of two cases of acute A-V block and four cases of chronic A-V block associated with coronary disease were studied by serial section. This showed that acute blocks in coronary disease are related to ischemia. Chronic blocks, however, have a mechanical factor associated with the ischemic factor. The mechanical factor is related to the effect of fibrosis and calcification of the summit of the ventricular septum upon the branching portion of the A-V bundle and the left bundle branch.
Permanent Pervenous Atrial Pacing from the Coronary Vein
Authors: KRAMER DAVID H. , MOSS ARTHUR J.
Published: June 2012

Permanent pervenous atrial pacing from the coronary vein has been attempted in 14 patients. Several types of arrhythmias including symptomatic bradycardia, "bradytachy" syndrome, and refractory ventricular tachyarrhythmia-fibrillation have been successfully treated with pervenous atrial pacing in 10 patients for 1 to 30 mo. Longterm atrial pacing was unsuccessful in four patients; in two of these four this was due to high atrial pacing thresholds. To date there has been no evidence of pacemaker perforation or pacemaker-induced coronary vein thrombosis. It is concluded that permanent pervenous atrial pacing from the coronary vein is a reliable method of atrial pacing without resorting to thoracotomy.
Systemic Hemodynamic and Myocardial Metabolic Effects of Isoproterenol and Angiotensin After Open-Heart Surgery
Authors: MUELLER HILTRUD S. , GREGORY JOHN J. , GIANNELLI STANLEY , AYRES STEPHEN M.
Published: June 2012

Cardiovascular dynamics and metabolism after open heart surgery were studied in 10 patients before and after infusion of angiotensin and isoproterenol. Patients with rheumatic mitral disease showed marked lowering of cardiac index with elevation of systemic vascular resistance in the control state while those with aortic disease demonstrated less depression of cardiac index and normal resistance. The group with mitral disease also showed lower coronary blood flow and much higher coronary vascular resistance than the aortic patients. Angiotensin caused further depression of cardiac index and marked increase in pressure work. Isoproterenol augmented cardiac index but did not affect pressure work significantly. Both agents increased oxygen consumption significantly by increment in coronary flow (isoproterenol) or by widening of myocardial oxygen extraction (angiotensin). Isoproterenol is favored over angiotensin in low output states after cardiac surgery as a means of meeting oxygen demands as well as the response of cardiac index.
Indirect Assessment of Left Ventricular Performance in Acute Myocardial Infarction
Authors: DIAMANT BERNARD , KILLIP THOMAS , Seides Stuart , Stanbridge Rex
Published: June 2012

One hundred patients admitted to a cardiac care unit had indirect serial determinations of left ventricular systolic ejection times. Patients were divided into groups with transmural infarction, nontransmural infarction, and no infarction, according to clinical, biochemical, and electrocardiographic criteria. Total electromechanical systole and left ventricular ejection time were shortened in acute myocardial infarction, whereas the pre-ejection period and its components, the Q-S
1
and isovolumic contraction time intervals, were prolonged. The most abnormal measurements were observed in patients with transmural infarction. Patients with nontransmural infarction demonstrated less severe abnormalities of the systolic ejection times, and the patients without infarction were the least affected. Some of the greatest deviations in the measured intervals were observed in the transmural infarction patients who died. Indirect measurement of left ventricular systolic ejection time is a valuable adjunct in the bedside assessment of left ventricular performance and provides a prognostic index for patients with acute myocardial infarction.
Effects of Training on the Distribution of Cardiac Output in Patients with Coronary Artery Disease
Authors: CLAUSEN JAN PRAETORIUS , TRAP-JENSEN JENS
Published: June 2012

In nine patients with coronary artery disease, cardiac output distribution was evaluated at rest and during exercise by measurement of cardiac output and regional blood flow parameters (hepatic and muscle blood flow). In seven patients repeated values were obtained after a physical training program of 4 to 10 weeks' duration. After training, cardiac output was reduced at moderate work loads (13.1%) causing a change of the relation between oxygen uptake and cardiac output from hyperkinetic to normal. During heavy exercise the cardiac output was increased (5.5%) after training. Similar changes were observed in muscle blood flow, which was reduced at submaximal loads (14.9%) and increased at maximal (8.6%). Hepatic blood flow showed in contrast a less pronounced reduction at both work loads after training (difference, 7.2%). These effects of training could be explained as peripheral regulatory alterations without implying primary improvement in myocardial performance. They are consistent with the view that local changes in the trained muscles are important for the reduction in myocardial pressure-work caused by physical conditioning.
Transvenous Cardiac Pacing
Authors: GULOTTA STEPHEN J.
Published: June 2012

Optimal electrode position for long-term transvenous cardiac pacing is in the apex of the right ventricle. Intracardiac electrograms, surface electrocardiograms, frontal fluoroscopy, lateral roentgenograms, and pacing threshold levels were studied in two groups of patients: One group was comprised of five patients with permanent pacemakers who had inadvertent malplacement of the pacing catheter, and the second group was composed of six patients undergoing temporary pacing from selected sites within the coronary venous system. The results of this study indicate that the appearance of a characteristic right ventricular endocardial complex recorded from the catheter tip is the most reliable guide to proper electrode placement. Low threshold levels, good position demonstrated roentgenographically, and typical surface electrocardiographic patterns of left bundle-branch block were all noted during intentional and following inadvertent malpositioning of the electrode within the coronary venous system and do not, therefore, guarantee proper positioning.

A successful routine for pacemaker insertion has been established which includes fluoroscopy, lateral roentgenograms, intracardiac and surface electrocardiograms, and threshold analysis. Satisfaction of all these tests appears to insure proper electrode positioning.
Therapeutic Defibrination and Heparin Therapy in the Prevention and Resolution of Experimental Venous Thrombosis
Authors: RAHIMTOOLA SHAHBUDIN H. , RAPHAEL MAURICE J. , PITNEY W. ROBERT , OLSEN ECKHARDT J. G. , WEBB-PEPLOE MICHAEL
Published: June 2012

The application of phenol to the femoral veins of anesthetized dogs resulted in an occluding thrombus in 24 of 25 veins at 1 week. Serial venography and eventual histology showed that these veins remained occluded over a 5-week observation period, the thrombi undergoing organization. Therapeutic defibrination was achieved with administration of an enzyme from venom of the pit viper (Arvin). Arvin, administered for 1 week immediately following phenol application and before thrombus formation had occurred, prevented thrombosis in all 10 such veins, and serial venography for a further 4 weeks showed that the veins remained patent. Administration of Arvin was begun 24 hours postoperatively, when venography had demonstrated an occluding thrombus and failed to clear any of 11 veins after 3 weeks of treatment.

Intravenous administration of heparin, 10,000 units, at 6, 6, and 12-hour intervals in a 24-hour period, was begun immediately after phenol application and continued for 1 week; 10 of 12 veins were blocked at 1 week. Following the same dose of heparin every 6 hours four of eight veins were blocked at 1 week.

The results indicate that when the vascular endothelium is damaged, therapeutic defibrination is more effective than heparin therapy in preventing venous thrombosis. Arvin therapy has no significant thrombolytic effect even if the thrombus is less than 24 hours old.
Splitting of Second Heart Sound in Patients with Aortic Regurgitation
Authors: AYGEN MAURICE M. , SIRKIS ITZHAK , WURZEL MORDEHAI
Published: June 2012

The intervals between the two components of the second heart sound (A
2
-P
2
), measured from the phonocardiograms of 50 patients with severe aortic regurgitation, were compared with those of 57 normal subjects. During expiration the second sound was single or closely split in both groups. Inspiratory augmentation of the A
2
-P
2
interval of less than 0.02 sec occurred in one normal subject (2%) and in 42 patients with aortic regurgitation (86%). Thus the great majority of patients with severe aortic regurgitation had either a single or a closely split second heart sound during both phases of respiration. The mean Q-A
2
intervals (rate corrected) of 30 patients, in whom severe aortic regurgitation was documented by contrast angiographic studies, were longer than those of normal subjects during both phases of respiration, and the difference was statistically more significant (
P
< 0.02) during inspiration. Thus prolongation of the Q-A
2
interval was the main factor responsible for the disappearance of the normal asynchrony of semilunar valve closure, in patients with aortic regurgitation.
Left Ventricular Dynamics in Complete Right Bundle-Branch Block with Left Axis Deviation of QRS
Authors: BARAGAN J. , FERNANDEZ F. , COBLENCE B. , SAAD Y. , LENÈGRE J.
Published: June 2012

The time intervals defined by the simultaneous recording of an electrocardiogram, phonocardiogram, indirect carotid pulse curve, and apexcardiogram made it possible to compare the left ventricular (LV) dynamics in a group of 33 cases of complete right bundle-branch block with left axis deviation (RBBB-LAD) with two control groups, one consisting of 30 cases of complete right bundle-branch block without left axis deviation (RBBB without LAD) and the other of 30 cases of left axis deviation (LAD) alone.

The LV dynamics of RBBB-LAD differed from those of both control groups of RBBB without LAD and of LAD alone by a significantly late onset of LV ejection in the former, resulting from both late onset and slow rise of LV contraction. On the other hand, the delayed LV activity was not significantly different between the group of RBBB-LAD and a previously studied group of complete left bundle-branch block.

Normal limits for these intervals were looked for to make it possible to diagnose a late LV activity in the individual patient, and so provide a further argument in the discussion for an eventual cardiac pacing in doubtful cases.

Finally, it was not felt possible to use these intervals to try to localize the site of the conduction disturbance, whether in the bundle branch or in the ventricular wall itself.
Comparison of the Peak Inotropic Effects of a Catecholamine and a Digitalis Glycoside in the Intact Canine Heart
Authors: BEISER G. DAVID , EPSTEIN STEPHEN E. , GOLDSTEIN ROBERT E. , STAMPFER MORRIS , BRAUNWALD EUGENE
Published: June 2012

The relative peak effects of isoproterenol and ouabain on myocardial contractility and cardiac output were compared by infusing increasing amounts of these two drugs into seven open-chest anesthetized dogs until toxicity developed. Just prior to the development of toxicity isoproterenol increased contractile force an average of 149% and the peak rate of force development (df/dt) an average of 278% of control values, compared to an increase of only 49% and 35%, respectively, with the administration of ouabain. Cardiac output and stroke volume were also significantly greater with the catecholamine than the glycoside. The combination of isoproterenol and ouabain produced essentially the same contractile force and stroke volume achieved by isoproterenol alone. Suppression of ouabain-induced arrhythmias by ventricular pacing allowed additional glycoside to be infused until ventricular fibrillation terminated the study. With pacing and ouabain, contractile force increased 131% above control, a level similar to that achieved by isoproterenol; peak df/dt increased to 200% above control, a value significantly lower than that obtained with isoproterenol. However, stroke volume decreased despite a substantial increase in left ventricular end-diastolic pressure. It is concluded that maximal doses of isoproterenol produce significantly greater increases in myocardial contractility and cardiac output compared to ouabain, even when the toxicity produced by the latter is suppressed by electrical stimulation.
Myocardial Blood Flow in Pacing-Induced Angina
Authors: CONTI C. RICHARD , PITT BERTRAM , GUNDEL WALTER D. , FRIESINGER GOTTLIEB C. , ROSS RICHARD S.
Published: June 2012

Current methods of measuring myocardial blood flow using
133
xenon have failed to separate normals from patients with ischemic heart disease at rest. In the present study such a separation was attempted by utilizing pacing-induced tachycardia (PIT) to stress the myocardium.
133
Xenon was injected into the left coronary artery to measure blood flow in 27 patients at rest and during pacing-induced tachycardia. Oxygen content was simultaneously measured in the aorta and coronary sinus of 13 of these patients. Pacing rates of 150 beats/min or greater were obtained in 21 patients. In 10 patients (group I), who developed ischemia, manifested either by typical angina or ischemic electrocardiographic changes during PIT, myocardial blood flow increased 32 ml/min/100 g of tissue (
P
< 0.001). In 17 patients (group II), who did not develop ischemia, myocardial blood flow increased 12 ml/min/100 g of tissue (
P
< 0.02). The increase in group I patients was significantly greater than in group II (
P
< 0.02). Myocardial oxygen consumption increased 4.63 ml/min/100 g of tissue (
P
< 0.01) in ischemic responders (group I) and 2.62 ml/min/100 g of tissue in nonischemic responders (group II). It is concluded that patients with an ischemic response to pacing-induced tachycardia had a greater increase in myocardial blood flow and myocardial oxygen consumption than patients who did not develop an ischemic response. This unexpected finding is best explained by an increased myocardial blood flow in the nonischemic areas of the myocardium which may result from a vasodilator response to ischemia.
The Influence of Atrial Pressure on Cardiac Performance Following Myocardial Infarction Complicated by Shock
Authors: BRADLEY R. D. , JENKINS B. S. , BRANTHWAITE M. A.
Published: June 2012

Performance curves for both sides of the heart were derived in six patients with acute myocardial infarction complicated by cardiogenic shock. Stroke index and right and left ventricular stroke work index were related to mean atrial pressures which were lowered by venesection. Values for cardiac index, stroke index, and stroke work index were all low, and little change occurred with alterations in atrial pressures. The relationship of right and left atrial pressures to the genesis of pulmonary edema is discussed, and the effects of isoproterenol (isoprenaline) are described.
Tritiated Digoxin
Authors: DOHERTY JAMES E. , FLANIGAN W. J. , MURPHY M. L. , BULLOCH R. T. , DALRYMPLE G. L. , BEARD O. W. , PERKINS W. H. , Gammill Jacquelyn , Sherwood Joyce
Published: June 2012

Metabolic turnover studies performed on six patients with surgically induced biliary fistula given tritiated digoxin reveal virtually all stool excretion of digoxin to be derived from bile. This establishes the relative lack of recycling of digoxin as an important factor in digoxin metabolism. This is probably related to its polar chemical structure and is a determinant of its clinical duration of action in human subjects. The amount of digoxin in the enterohepatic circulation (recycling) was calculated to be 6.5% of the administered dose and absolute absorption to be 85% in human subjects.
Electrocardiographic Differentiation Between Left Ventricular Hypertrophy and Anterior Myocardial Infarction
Authors: KINI P. M. , EDDLEMAN E. E. , PIPBERGER H. V.
Published: June 2012

Electrocardiograms recorded from patients with uncomplicated left ventricular hypertrophy (LVH) often show loss of initial anteriorly directed QRS forces. An attempt was made to differentiate these records from electrocardiograms showing a similar pattern as a result of anterior myocardial infarction (MI). Orthogonal ECGs (Frank system) obtained from 103 patients with LVH were compared to ECG obtained from 327 patients with MI. The ECG were selected on the basis of absence of Q waves in lead Z which in the conventional ECG corresponds to absence of the R wave in right precordial leads. With two simple scalar measurements, namely R amplitude in lead X ≥ 1.2 mv and the sum of amplitudes of R in leads X and Z ≥ 2.5 mv, 66% of LVH cases were recognized. With these criteria, 88% of the MI records were also correctly classified. The same measurements identified 59% of an independent sample of 66 cases of LVH with no Q in lead Z. By utilizing linear discriminant function analysis, 75% of the cases of LVH, 80% of the MI, and 70% of the independent group of LVH were correctly classified.

Classification procedures were also tested on 48 autopsy cases with results slightly inferior to those obtained on clinical samples.

Direction of initial instantaneous QRS vectors in the transverse plane proved to be much less efficient than scalar measurements or multivariate analysis in the separation between LVH and MI.

This study confirms the difficulties concerning the correct interpretation of the significance of loss of anteriorly directed forces in the presence of LVH. However, the error rate in diagnosis can be considerably reduced by the use of criteria proposed on the basis of this investigation.
The Oslo Diet-Heart Study
Authors: LEREN PAUL
Published: June 2012

The study deals with 412 men, aged 30 to 64 years, randomized 1 to 2 years after a first myocardial infarction. For the experimental group a diet low in saturated fats and cholesterol, and high in polyunsaturated fats was recommended. After 5 years, as reported previously, the incidence of fatal and nonfatal myocardial reinfarction was found to be significantly reduced. "Sudden death" was uninfluenced. Major coronary heart disease (CHD) relapses, including fatal and nonfatal events (MI), were significantly reduced (
P
= 0.05).

After 11 years, death from all causes had occurred in 101 of the original dieters and 108 controls. A significantly reduced myocardial infarction mortality in the original diet group was found (32 versus 57,
P
= 0.004). The total number of coronary deaths (fatal myocardial infarction and sudden death) was 79 in the diet group and 94 in the control group (
P
= 0.097).

The CHD mortality was correlated with age, serum cholesterol level, blood pressure, body weight, smoking habits, and a combination of these risk factors.
The 5-Year Experience of Modified Fat Diets on Younger Men with Coronary Heart Disease
Authors: BIERENBAUM MARVIN L. , FLEISCHMAN ALAN I. , GREEN DONALD P. , RAICHELSON ROBERT I. , HAYTON THOMAS , WATSON PORTIA B. , CALDWELL ANNE B.
Published: June 2012

This is a study of 100 men, 30 to 50 years old, with documented coronary artery disease and past myocardial infarction who were placed under dietary management with a 28% fat diet. One hundred men whose diets were not managed were matched with regard to age at entry to the study, age at infarction, number of infarctions, blood pressure level, degree of angina, and serum cholesterol level among other factors. Over a period of 5 years the diet-managed group experienced and maintained a significant reduction in serum cholesterol level which the nondiet-managed group did not. Under the diet and experimental conditions employed, with saturated fat content below 9% of calories, and cholesterol intake below 400 mg per day, the degree of unsaturation of the fats in the experimental diets did not appear to influence serum cholesterol value or mortality. The serum triglyceride level was significantly lower in the diet-managed group than in the nondiet-managed group; this was presumably related to weight reduction. In the group under dietary management, fatal and nonfatal myocardial reinfarction rates were lower but were statistically significantly so only for the fatal infarction rates in men under age 45. Serum phospholipids above 220 mg/100 ml were associated with a significantly lower rate of recurrent infarction.