bluuebunny/crossref_metadata_2025 huggingface dataset:
Contrasting influences of alterations in ventricular preload and afterload upon systemic hemodynamics, function, and metabolism of ischemic myocardium.
Authors: Wyatt H L , Da Luz P L , Waters D D , Swan H J , Forrester J S
Published: June 2012

This study of anesthetized, open-chest dogs compares the effects of primary increases in left ventricular preload and afterload upon global and regional myocardial function and metabolism in the presence of a left anterior descending coronary artery stenosis (LAD). When LAD flow was reduced to 40-50% of control, regional systolic shortening declined by 20 to 25% and regional lactate extraction changed to production. In seven control dogs the mechanical abnormalities persisted during the 30 min of observation, but lactate production was reduced spontaneously. In ten dogs, increases in left ventricular end-diastolic pressure (LVEDP) during dextran infusion were associated with increases in cardiac output and regional systolic shortening; however, regional lactate production also increased (P less than 0.05) despite an augmentation in LAD flow. In seven dogs mean arterial pressure increased by an average of 32 mm Hg during angiotensin infusion (0.2 to 0.4 mug/kg/min); LVEDP did not change but cardiac output decreased significantly. LAD artery flow improved markedly and lactate production shifted to extraction (P less than 0.05) while systolic shortening remained unchanged. When angiotensin was discontinued, lactate extraction worsened again. Thus, in the presence of a severe coronary stenosis, a primary increase in preload improves cardiac output but at the expense of aggravated ischemia. In contrast, a primary increase in afterload reduces cardiac output but may improve perfusion and lactate uptake of the ischemic myocardium.
Quantitative coronary arteriography: estimation of dimensions, hemodynamic resistance, and atheroma mass of coronary artery lesions using the arteriogram and digital computation.
Authors: Brown B G , Bolson E , Frimer M , Dodge H T
Published: June 2012

More accurate characterization of coronary artery lesions is needed for evaluation of short and long-term interventions in coronary disease. A method of segmental artery analysis has been developed to maximize the information obtained from coronary arteriograms. Coronary lesions are traced from two projected, perpendicular, 35 mm cineangiographic views and transmetted, in digital form, to a PDP 11/45 computer. Magnification and distortion of the image are compensated for in order to determine the actual vessel profiles, using the catheter and its location as a scaling device. The two views are matched; a spatial representation of the vessel centerline is constructed mathematically; and orthogonal vessel diameters are computed at increments along this centerline. Assuming an elliptical lumen, the absolute and percentage reduction in diameter and cross-sectional area in the stenosis are computed. More complex functions (integrated atheroma mass, Poiseuille resistance, and orifice resistance) are then calculated. The accuracy and variability of the different steps involved in lesion analysis have been determined. Dimensional accuracies of +/- 150 microns (SD) are feasible. Examples are given of patients with Prinzmetal's angina and with progressive coronary disease.
Interventricular septal motion in patients with proximal and distal left anterior descending coronary artery lesions.
Authors: Gordon M J , Kerber R E
Published: June 2012

In order to evaluate the ability of the echocardiogram to detect and localize left main or left anterior descending (LAD) coronary artery lesions, 43 patients were studied. The systolic excursion of the left side of the septum and the ratio of posterior wall to septal excursion were measured. Seventeen patients had no LAD lesions; all had systolic septal excursion of 3 mm or greater. Twelve patients with septal excursion of 2 mm or less all had left main or LAD lesions, but 14 other patients with LAD lesions had septal excursions of 3 mm or greater. Nine of 16 patients with LAD lesions proximal to the first septal branch had reduced or absent septal excursion, as did three of ten with LAD lesions distal to the first septal branch. In a setting of coronary artery disease reduced or absent septal motion on echocardiography suggests involvement of the left main or left anterior descending coronary. However, the technique is relatively insensitive, with 54% of the LAD patients having normal septal motion.
Two-dimensional echocardiographic assessment of vegetative endocarditis.
Authors: Gilbert B W , Haney R S , Crawford F , McClellan J , Gallis H A , Johnson M L , Kisslo J A
Published: June 2012

Real-time, two-dimensional echocardiography was used to document the presence and assess the size and location of vegetative lesions of the cardiac valves and chambers in seven patients with bacterial endocarditis. Anatomic correlation (surgical or autopsy) was accurate in all patients. Two-dimensional echocardiography was shown to be of particular value in determining morphologic characteristics of the lesions since this technique provides spatial information concerning moving cardiac structures. The results of two-dimensional echocardiography were most helpful in determining selected aspects of the clinical care provided for each patient. These data demonstrate that real-time, two-dimensional echocardiography, in combination with M-mode imaging techniques, may be of great potential value in the detection of vegetative endocarditis. Furthermore, reliable assessment of lesion size and location may, in time, become a valuable method for following the morphologic changes that occur in vegetative lesions, and thus determine the efficacy of antibiotic therapy. This information may also provide a means for evaluating certain patients for surgical intervention.
The relationship between the metabolism of procainamide and sulfamethazine.
Authors: Giardina E-GV  , Stein R M , Bigger J T
Published: June 2012

The metabolism of sulfamethazine (SMZ), which is acetylated by a binodally distributed enzyme, and procainamide (PA) was compared in 21 normal volunteers, each given a single oral dosted metabolites, N-acetyl-procainamide (NAPA) and Ac-SMZ, were measured. Subjects with less than 64% Ac-SMZ in the 0-8 hour collection were termed "slow" and those with more than 64% were termed "fast" SMZ acetylators. Slow SMZ acetylators had 9.8 to 43.8% (24.1 +/- 10.13) NAPA recovered, and fast SMZ acetylators, 22.0 to 42.6% (33.7 +/- 7.29) NAPA, P less than 0.01. In addition, the calculated half-life of PA metabolism for slow SMZ acetylators was 9.0 to 33.8 hours (18.4 +/- 8.82) and for fast SMZ acetylators was 8.1 to 14.4 hours (10.9 +/- 2.19), P less than 0.01. For four subjects, SMZ acetylation phenotype did not correlate with the half-life of SMZ or PA metabolism; and in two, SMZ acetylation phenotype and half-life of metabolism did not correlate with the same PA indices. Even though slow SMZ acetylators have less NAPA recovered than fast SMZ acetylators, it is not yet clear that procainamide is metabolized by a bimodally distributed enzyme as is sulfamethazine.
Long-lasting effect of oral molsydomine on exercise performance: a new antianginal agent.
Authors: Takeshita A , Nakamura M , Tajimi T , Matsuguchi H , Kuroiwa A
Published: June 2012

This study examines whether the beneficial effects of molsydomine, a recently introduced antianginal agent, on exercise performance of patients with angina pectoris are long lasting. The hemodynamic effects are known to persist for several hours. The effects of molsydomine on the duration of exercise and the time to the onset of ST depression were compared to those of placebo during two hours after oral administration. Molsydomine prolonged the duration of exercise in all eight patients (average 2.8 min, P less than 0.001) and delayed the onset of ST depression (average 2.2 min, P less than 0.001), while the placebo failed to alter these measurements. The increment of the duration of exercise produced by 2 mg of molsydomine in two hours following oral administration was comparable to the increment produced in a few minutes after 0.3 mg of nitroglycerin given sublingually. The results indicate that molsydomine offers prophylasis for angina pectoris that lasts at least two hours after oral administration.
Ventricular apical vents and postoperative focal contraction abnormalities in patients undergoing coronary artery bypass surgery.
Authors: Shaw R A , Kong Y , Pritchett E L , Warren S G , Oldham H N , Wagner G S
Published: June 2012

Ventriculograms made 9-15 months after surgery in 48 patients with normal preoperative apical contraction were reviewed to determine the influence of apical venting on apical wall motion in patients undergoing coronary bypass surgery. After interpretation of postoperative apical wall motion, the patients were subdivided into two groups. One group consisted of 34 patients who were vented by inserting a catheter through the apex of the left ventricle and the second group included 14 patients in whom no transventricular vent was made. The two groups were similar clinically and hemodynamically before surgery, and the surgical procedures were similar with the exception of vent site. Following surgery, incidences of graft patency and antegrade flow to the apex were also similar. Nineteen (56%) patients in the apically vented group had apical dyskinesia or akinesia observed on the postoperative ventriculogram while none of the patients who were not apically vented had these findings. None of the patients with apical dyskinesia or akinesia had congestive heart failure following surgery. The postoperative ventriculograms of 12 patients with mitral stenosis who underwent valvulotomy by inserting a Tubbs dilator through the apex were also analyzed. Only one patient (8.5%) had apical dyskinesia or akinesia. Since the patients with mitral stenosis probably did not have significant coronary artery disease, it is possible that the combination of the apical vent and ischemic heart disease was responsible for the focal contraction abnormalities observed.
Evaluation of the CO2 rebreathing cardiac output method in seriously ill patients.
Authors: Franciosa J A
Published: June 2012

The CO2 rebreathing cardiac output method is a totally noninvasive Fick procedure needing validation in various disease states to become clinically applicable. Simultaneous measurements of cardiac output by CO2 rebreathing and dye-dilution or direct Fick techniques were performed in 53 patients. In nine patients with pulmonary disease rebreathing cardiac output averaged 4.85 L/min compared to 5.18 L/min by dye-dilution or Fick (r = 0.16). In 14 instances of acute myocardial infarction cardiac output was 5.53 L/min by rebreathing and 5.87 L/min by dye-dilution (r = 0.95), while in nine shock cases it averaged 3.98 L/min by dye-dilution or Fick and 3.75 L/min by CO2 rebreathing (r = 0.94). In five heart failure cases with mitral insufficiency, which may distort dye durves, correlation between standard and rebreathing methods was r = 0.09, but in 16 cases without mitral regurgitation, r = 0.89. Acute interventions in ten patients increased dye-dilution cardiac output by 0.92 L/min and rebreathing outputs by 0.60 L/min (r = 0.87). The data suggest that the CO2 rebreathing cardiac output method may be useful in the CCU-MICU setting.
Cryosurgical ablation of the A-V node-His bundle: a new method for producing A-V block.
Authors: Harrison L , Gallagher J J , Kasell J , Anderson R H , Mikat E , Hackel D B , Wallace A G
Published: June 2012

A cryosurgical instrument was used to ablate atrioventricular conduction. The procedure was carried out in 20 dogs and subsequently in three patients with drug resistant, life-threatening supraventricular tachycardias. In patients, the cryosurgical unit lowered the temperature of the His bundle area to 0 degrees C, effecting complete but reversible heart block. Rewarming resulted in resumption of normal atrioventricular conduction. The His bundle region then was cooled to -60 degrees C; complete heart block was produced with two or more 90-120 second freezes. Postoperative evaluations revealed persistent atrioventricular conduction block. The lesion showed no tendency to rupture, form aneurysm, or interfere with valvular function. In the clinical cases, postoperative studies demonstrated a stable pacemaker arising proximal to the branching portion of the His bundle. A potential application of the cryosurgical technique might be ablation of sites of dysrhythmia (i.e., ectopic foci, re-entry circuits, accessory pathways).
Cryosurgical ablation of accessory atrioventricular connections: a method for correction of the pre-excitation syndrome.
Authors: Gallagher J J , Sealy W C , Anderson R W , Kasell J , Millar R , Campbell R W , Harrison L , Pritchett E L , Wallace A G
Published: June 2012

Cryothermia, a new technique for definitive treatment of the pre-excitation syndrome, is described in two patients. The first patient presented with a normal P-R interval with a delta wave and reciprocating tachycardia. Preoperative electrophysiologic study suggested a free-wall atrioventricular connection on the left posterior atrioventricular (A-V) groove. At surgery, epicardial mapping confirmed the site of pre-excitation on the posterior left ventricular (LV) wall. An electrogram arising from the accessory pathway (AP) was recorded at the site of earliest ventricular activation. Interatrial delay combined with an apparently long accessory pathway to the ventricle caused the P-R interval to appear normal. Local pressure abolished pre-excitation. The site of early ventricular activation was cooled to -60 degrees C with a specially designed cryoprobe. All evidence of pre-excitation and arrhythmias disappeared. The second patient presented with a refractory reciprocating tachycardia and was found to have an AP in the septum capable of only retrograde conduction. Retrograde conduction was abolished by applying a temperature of 0 degrees C to the anulus at this site during tachycardia. Conduction over the AP and reciprocating tachycardia returned with rewarming. Ablation of the AP was obtained by applying a temperature of -60 degrees C for 90 seconds on two occasions to the same area. The His bundle was not injured.
Pre and postoperative ventricular function in infants and children with right ventricular volume overload.
Authors: Nakazawa M , Jarmakani J M , Gyepes M T , Prochazka J V , Yabek S M , Marks R A
Published: June 2012

Hemodynamic and ventricular volume parameters were evaluated in 21 patients (24 studies) with total anomalous pulmonary venous return (TAPVR), 11 patients with secundum atrial septal defect (ASD), and eight patients who had complete correction of TAPVR or ASD. Right and left ventricular (RV and LV) volume parameters were calculated according to Simpson's rule and the area length methods, respectively. In infants with TAPVR, RV end-diastolic volume was larger than normal, but RV ejection fraction was significantly less than normal. LV end-diastolic volume and LV ejection fraction were all less than normal in infants with or without pulmonary hypertension, and the values did not correlate with the cardiorespiratory symptoms. In children with TAPVR or ASD, RV end-diastolic volume and output were higher than normal preoperatively and decreased to normal or near normal values postoperatively. The data suggest that pulmonary venous obstruction and/or RV failure are responsible for cardiorespiratory symptoms in infants with TAPVR and early surgical intervention is recommended in these patients.
Late development of pulmonary venous obstruction following Mustard's operation using a dacron baffle.
Authors: Driscoll D J , Nihill M R , Vargo T A , Mullins C E , McNamara D G
Published: June 2012

Three patients developed late pulmonary vein obstruction (PVO) following Mustard's operation for transposition of the great arteries. In all three the absence of PVO had been documented by an earlier postoperative cardiac catheterization. At reoperation shrinkage and kinking of the dacron baffle was evident. After Mustard's operation, patients should be observed closely for symptoms and signs of PVO since it can occur insidiously despite previously proven absence of this complication.
Prevalence and characteristics of disproportionate ventricular septal thickening in patients with acquired or congenital heart diseases: echocardiographic and morphologic findings.
Authors: Maron B J , Clark C E , Henry W L , Fukuda T , Edwards J E , Mathews E C , Redwood D R , Epstein S E
Published: June 2012

Echocardiographic and necropsy studies were performed in 304 patients with various cardiac diseases. The overall prevalence of disproportionate ventricular septal thickening (septal to free wall ratio greater than or equal to 1.3) was 10%. However, it was related to the type of cardiac lesion. Prevalence was high (greater than 20%) in pulmonary stenosis or primary pulmonary hypertension, lower (less than 15%) in Eisenmenger syndrome or aortic or mitral valvular disease and was not present in atrial or ventricular septal defect. In right ventricular overload, prevalence of disproportionate septal thickening correlated with increasing ventricular systolic pressure. None of 16 patients with disproportionate septal thickening studied at necropsy showed marked disorientation of cardiac muscle cells in the ventricular septum, characteristic of genetically transmitted asymmetric septal hypertrophy (ASH). Furthermore, disproportionate septal thickening was demonstrated by echocardiography in only one of 59 first degree relatives of patients with disproportionate septal thickening and associated cardiac diseases. Thus, disproportionate ventricular septal thickening associated with other cardiac diseases usually is due to secondary hypertrophy and is not a manifestation of genetically transmitted ASH.
Contrast echocardiography in single or common ventricle.
Authors: Seward J B , Tajik A J , Hagler D J , Ritter D G
Published: June 2012

Common ventricle is a rare congenital anomaly in which the ventricular chamber receives blood from two separate atrioventricular valves or from a common atrioventricular valve. We used contrast echocardiography during cardiac catheterization to confirm ventricular anatomy and to characterize blood flow dynamics in 35 patients with common ventricle. After injections of dye, a cloud of echoes anterior to the mitral valve echo during the rapid inflow phase of ventricular diastole is indirect evidence of common ventricle with two atrioventricular valves. Common ventricle with an outflow chamber is characterized by a smaller ventricular chamber visualized anterior to both atrioventricular valves which opacifies with subsequent ventricular systole. The arrival of all dye posterior to the only recorded atrioventricular valve further established the presence of a single atrioventricular valve. These contrast flow patterns gave greater specificity to the standard M-mode echocardiographic assessment of patients suspected of having common ventricle.
Aschoff bodies in operatively excised atrial appendages and in papillary muscles. Frequency and clinical significance.
Authors: Virmani R , Roberts W C
Published: June 2012

Among 481 patients undergoing various mitral valve operations, Aschoff bodies were found in 40 (21%) of 191 operatively excised left atrial appendages, in four (2%) of 273 operatively excised left ventricular papillary muscles (1 per patient), and in one (6%) of 17 patients with both left atrial appendage and papillary muscle operatively excised. Of the total of 45 patients with Aschoff bodies, 44 preoperatively had mitral stenosis, and only one, a 10-year-old boy, had pure mitral regurgitation. Sinus rhythm was present in 38 (84%), and atrial fibrillation in seven (16%). Perioperatively, only one of the 45 patients with Aschoff bodies had clinical or laboratory stigmata compatible with acute rhematic fever, and 58% had an illness compatible with acute rheumatic fever at any time.
Left ventricular mechanical efficiency in man with heart disease.
Authors: Baxley W A , Dodge H T , Rackley C E , Sandler H , Pugh D
Published: June 2012

Thirty-eight adults with valvular and/or myocardial disease had heart catheterization with coronary blood flow and myocardial O2 consumption (MVO2) per 100 g measured by the nitrous oxide washout technique. Quantitative biplane angiocardiography was performed to assess left ventricular volume, mass, ejection fraction and work. Left ventricular efficiency was calculated from work, MVO2/100 g and mass. Efficiency ranged from 4 to 40% and was normal in some patients with severe ventricular pressure-volume work overloads. Total left ventricular MVO2 ranged up to 461 ml/min. Neither total MVO2 nor MVO2/100 g was significantly related to ventricular work, ejection fraction, or tension-time index. These data suggest 1) a relationship between left ventricular efficiency and myocardial function in chronic valvular or myocardial disease, 2) that efficiency may be normal in hypertrophied ventricles, and 3) that chronic increases in resting ventricular metabolic requirements are met by hypertrophy rather than by increased MVO2/100 g.
Alternans of the ST segment in Prinzmetal's angina.
Authors: Kleinfeld M J , Rozanski J J
Published: June 2012

Alternans of the elevated ST segment (STEA) was found in 8 of 21 patients (38%) with Prinzmetal's variant angina. In addition to STEA, all eight patients had varying cardiac arrhythmias: multiple premature ventricular depolarizations in eight, ventricular tachycardia in five, and ventricular fibrillation in three. There was no consistent temporal relationship between the occurrence of STEA and the cardiac arrhythmias. Alternans occurred during periods when no arrhythmias were present. All eight patients underwent coronary angiography. Spontaneous coronary artery spasm was documented angiographically in three patients including two who had minimal or no coronary atherosclerotic disease. Six patients had severe, fixed, occlusive coronary artery disease. Possible mechanisms for STEA include: 1) failure of regions of myocardium to depolarize on alternate beats due to variation in conduction and refractoriness between ischemic and nonischemic zones of myocardium, and 2) electrical alternans of the transmembrane action potential during phase 2 and 3 (repolarization) caused by changes in the rate and extent of electrolyte transfer across cell membranes during ischemia. It is postulated that STEA is an electrocardiographic sign in the surface ECG of a dysequilibrium of refractory periods during ischemia and reflects an unstable electrical state of the myocardium.
Effect of the calcium antagonist verapamil on necrosis following temporary coronary artery occlusion in dogs.
Authors: Reimer K A , Lowe J E , Jennings R B
Published: June 2012

Calcium metabolism may play an important role in the pathogenesis of myocardial ischemic injury. The effect of the sarcolemmal calcium flux inhibitor, verapamil, on myocardial necrosis was studied in dogs subjected to temporary coronary artery occlusion. One group of dogs was untreated. A second group was given 0.8 mg/kg verapamil intravenously over a 30 min period beginning 10 min prior to coronary occlusion. In a third group, the dose of verapamil was increased until complicated by hypotension or conduction abnormalities. Cardiac necrosis was produced in all dogs by 40 min of left circumflex coronary artery occlusion followed by 2--4 days of reperfusion. At the end of the experiment, animals were sacrificed and necrosis was quantitated histologically in transmural slices through the posterior papillary muscle. Pre-treatment with the lower dose of verapamil resulted in significantly less necrosis (14% treated vs 35% untreated) with minimal hemodynamic consequences. Higher does of verapamil were even more effective in limiting cardiac necrosis despite the development of hypotension and varying degrees of heart block.
Echocardiographic, angiocardiographic, and surgical correlations in right ventricular myxoma simulating valvar pulmonic stenosis.
Authors: Chandraratna P A , San Pedro S , Elkins R C , Grantham N
Published: June 2012

The echocardiographic, angiographic and surgical correlations in a patients with a right ventricular myxoma simulating valvar pulmonic stenosis are presented. A dense mass of echoes was seen in the body of the right ventricle in diastole; in the right ventricular outflow tract throughout the cardiac cycle; and within the pulmonic valve in systole. These echocardiographic findings suggested the presence of a mass high in the right ventricle, which moved throught the pulmonic valve in systole. This impression was confirmed by angiography and surgery. A 53 mmHg gradient across the pulmonic valve was noted at cardiac catheterization. At operation a myxoma which originated above the crista supraventricularis was found. The tumor moved into the main pulmonary artery in systole. Surgical removal of the tumor resulted in the disappearance of the abnormal echoes.
The role of the QT interval in the sudden infant death syndrome.
Authors: Kelly D H , Shannon D C , Liberthson R R
Published: June 2012

To evaluate the role of QT interval prolongation in the genesis of the sudden infant death syndrome (SIDS), the post-resuscitation electrocardiograms of 21 aborted SIDS infants were reviewed. The infants had been found apneic, cyanotic, limp and unresponsive during sleep and required vigorous physical stimulation and mouth-to-mouth resuscitation. Three subsequently experienced repeat similar episodes from which they could not be resuscitated. Extensive studies eliminated all "known" etiologies for death. The QT intervals of these infants were compared to age and sex matched normal infants as well as to established normal values in the literature; in both the aborted and the subsequent actual SIDS infants, the QT intervals were not significantly different from those of the normal population. Thus, we conclude that QT intervals prolongation does not play a major role in the genesis of the aborted SIDS.
Participation of fast and slow A-V nodal pathways in tachycardias complicating the Wolff-Parkinson-White syndrome. Report of a case.
Authors: Amat-y-Leon F , Wyndham C , Wu D , Denes P , Dhingra R C , Rosen K M
Published: June 2012

Electrophysiological studies in one patient with type B pre-excitation and dual A-V nodal pathway revealed several types of paroxysmal narrow QRS tachycardia (PSVT). One type of PSVT reflected antegrade fast A-V nodal pathway and retrograde anomalous pathway conduction. This PSVT was characterized by early retorgrade activation of right atrial appendage, P following QRS and cycle length of 290 to 350 msec. A second PSVT reflected antegrade slow A-V nodal pathway and retrograde anomalous pathway conduction. This PSVT was characterized by early retrograde activation of right atrial appendage, P following QRS, and cycle length of 440 msec. A third PSVT reflected A-V nodal re-entrance with antegrade slow pathway and retrograde fast pathway conduction. This PSVT was characterized by normal retrograde atrial activation sequences, P simultaneous with QRS, and cycle length of 320 msec. All PSVT inductions could be explained in terms of antegrade and retrograde properties of fast and slow A-V nodal and anomalous pathways.
De subitaneis mortibus. XXIII. Rheumatoid arthritis and ankylosing spondylitis.
Authors: James T N
Published: June 2012

The conduction system of the heart was carefully examined at necropsy in two cases of rheumatoid arthritis and one of ankylosing spondylitis. All three patients had cardiac electrical instability and two fo the three died suddenly. The electrophysiological abnormalities of the three patients included paroxysmal atrial fibrillation in the first case, sustained atrial fibrillation with complete heart block and escape atrioventricular (A-V) junctional rhythm in the second case, and progressively increasing heart block eventually became complete in the third case. The sinus node exhibited extensive focal degeneration with and without associated inflammation in all three hearts, but the sinus node artery was not remarkably abnormal in any of these. All three hearts had important focal degenerative disease in the A-V node and His bundle, and in each of these there was marked narrowing of the local nutrient arteries, amounting to virtual occlusion in two hearts. The probable relationship of these postmortem histological findings to the electrocardiographic disturbances in each patient is discussed. Abnormalities in the cardiac conduction system of the hearts of these three patients are compared to ones previously reported for disseminated lupus erythematosus, polyarteritis nodosa, and scleroderma heart disease.
The effect of exercise training on heart rate during coitus in the post myocardial infarction patient.
Authors: Stein R A
Published: June 2012

The effect of interval exercise training on the peak coital heart rate in post myocardial infarction patients was studied. Sixteen men (ages 46-54) underwent a 16-week bicycle ergometer training program 12 to 15 weeks following their first myocardial infarction. Portable ECG tape recorders were used to record the ECG during coitus twice before and twice after the training program. The maximum minute oxygen consumption (VO2max) was measured in each subject during bicycle ergometer ECG examinations before and after the training program. A control group of six post myocardial infarction patients who were not trained was evaluated in the same manner. The exercise-trained group had an average increase in VO2max of 11.5%(2.7 to 3.0 L/min) and an average decrease in peak coital heart rate of 5.5%(127/min to 120/min). The control group demonstrated a 2% increase in VO2max and no significant change in peak coital heart rate. The increase in aerobic capacity (VO2max) and the consequent reduction in peak coital heart rate in our trained group suggests the potential value of exercise training in improving sexual function in the patient with angina during coitus.
Effect of angina on the left ventricular diastolic pressure-volume relationship.
Authors: Mann T , Brodie B R , Grossman W , McLaurin L P
Published: June 2012

The increased left ventricular end-diastolic pressure associated with myocardial ischemia was studied in 19 patients at cardiac catheterization. Single plane left ventriculograms were performed using high fedelity micromanometer tipped catheters before and immediately following rapid atrial pacing. Left ventricular diastolic properties were evaluated by constructing diastolic pressure-volume curves from the simultaneous pressure and volume data. In seven control patients, there was no significant change in left ventricular hemodynamics or the diastolic pressure-volume curve after atrial pacing. Twelve patients with significant coronary artery disease developed angina during pacing and had an increased left ventricular end-diastolic pressure (18 +/- 2 mm Hg, control, vs 30 +/- 2 mm Hg, angina, P less than .01) in the immediate post-pacing period. In these patients, the post-pacing ejection fraction was modestly decreased (0.63 +/- 0.03, control, vs 0.57 +/- 0.03, angina P less than 0.01), and left ventricular volumes at end systole (59 +/- 8 cc, control, vs 74 +/- 9 cc, angina, P less than 0.0125) were increased. The post-pacing diastolic pressure-volume curves in all 12 patients were shifted upward as compared with control so that for any given diastolic volume, pressure was higher during angina. The data indicate that the increased left ventricular diastolic pressure during myocardial ischemia is the result of both impaired left ventricular systolic performance and altered left ventricular diastolic properties.
Suppression of premature ventricular contractions by acebutolol.
Authors: Gradman A H , Winkle R A , Fitzgerald J W , Meffin P J , Stoner J , Bell P A , Harrison D C
Published: June 2012

The antiarrhythmic action of the beta-blocking drug, acebutolol, was evaluated in patients with frequent premature ventricular contractions (PVCs). In the 12 hours following administration of a single 300 mg oral dose, 8 of 10 patients showed a greater than 50% reduction in PVC frequency, and statistical analysis indicated that PVC reduction persisted for 10 hours after the single dose. Analysis of plasma concentrations of acebutolol and an acetyl metabolite indicated that after single oral doses of plasma concentrations of the metabolite exceed those of unchanged acebutolol. When patients were studied during periods of 300 mg doses every 8 hours, eight of 11 showed a 70% reduction in PVC frequency, and analysis showed that the therapeutic effect was present throughout the 24-hour monitoring period. Acebutolol slowed the heart rate and prolonged the PR interval without affecting the QT interval. Significant clinical or laboratory toxicity was not encountered. In the small group studied, acebutolol was found to be safe and effective for short-term administration to patients with frequent PVCs and possessed a relatively long duration of antiarrhythmic action.
Cardiac, skeletal and ophthalmologic abnormalities in relatives of patients with the Marfan syndrome.
Authors: Payvandi M N , Kerber R E , Phelps C D , Judisch G F , El-Khoury G , Schrott H G
Published: June 2012

Nine patients with the Marfan syndrome and 40 of their first degree relatives were evaluated for the presence of cardiac, skeletal and ophthalmologic abnormalities. Aortic root dilatation and mitral valve prolapse were sought by echocardiography, and the metacarpal index was calculated from hand X-rays. Abnormalities of all the tests performed were present in all nine index cases, except for one normal eye exam. Mitral prolapse was present in thirteen relatives (33%) and aortic root dilatation in seven (18%). At least one cardiac abnormality was present in nineteen (47%) relatives. Aortic root dilatation was more common in male relatives; the incidence of mitral prolapse was approximately equal in the two sexes. Abnormal metacarpal index (greater than 8.0) occurred in fifteen of twenty-six relatives examined (58%). Ophthalmologic abnormalities were found in only four relatives. Two relatives had abnormalities of all three organ systems evaluated, five others had abnormalities of two systems, and fourteen had abnormalities of one system. We conclude that cardiac and skeletal abnormalities are demonstrable in a high percentage of first degree relatives of patients with the Marfan syndrome.
Rupture of ventricular septum or papillary muscle complicating myocardial infarction.
Authors: Vlodaver Z , Edwards J E
Published: June 2012

Ninety-eight specimens with rupture of some portion of the left ventricle complicating acute myocardial infarction from atherosclerotic coronary disease were studied. In 90, a single structure (so-called isolated rupture) had ruptured as follows: free wall of left ventricle, 52 cases; ventricular septum, 18 cases; a papillary muscle, 20 cases. In eight cases, two structures had ruptured, the most common combination being rupture of ventricular septum and left ventricular wal. Inferolateral location of underlying infarction was the common situation in ruptured papillary muscle, while anteroseptal myocardial infarction was more common in rupture of the ventricular septum. Transmural infarction underlay each case of ruptured ventricular septum, while in ruptured papillary muscle 11 of 20 cases showed subendocardial infarction. There was no association between the type of papillary muscle rupture and the type of infarct. Clinically, collapse of the circulation was common in cases of ruptured ventricular septum and ruptured papillary muscle. Death within one week after rupture was usual when the papillary muscle was involved totally or when the ventricular septum was involved. With partial rupture of a papillary muscle, longer survival (months) was observed in two of ten cases.
Noninvasive assessment of cardiac function and ventricular dyssynergy by precordial Q wave mapping in anterior myocardial infarction.
Authors: Awan N A , Miller R R , Vera Z , Janzen D A , Amsterdam E A , Mason D T
Published: June 2012

To determine whether multiple lead precordial electrocardiographic recordings offer an improved index for noninvasive estimation of left ventricular hemodynamic function and segmental dyssynergy, precordial mapping was performed in patients with anterior myocardial infarction, and the number of pathologic Q waves (greater than or equal to 0.04 sec) was counted (Q-Index). Left ventricular function was determined by cardiac catheterization and angiography and correlated with the Q-Index. The Q-Index correlated well with dyssynergy extent (r = 0.84) and inversely with ejection fraction (r= -0.87), stroke work index (r = -0.79) and cardiac index (r = =0.66). Three patient groups were defined by Q-Index; group I, 0.04 sec Q complexes less than 15; group II, 15-25; group III, 26-35. Q-Index related closely to functional classification and survival (mean follow-up 12.2 months): group I, 91%; group II, 81%; group III, 40%. Thus 35-lead precordial Q wave mapping with determination of total number of pathologic Q waves permits practical, atraumatic assessment of hemodynamic and functional status and allows prediction of survival in acute and chronic anterior myocardial infarction.
The effect of propranolol on microvascular injury in acute myocardial ischemia.
Authors: Kloner R A , Fishbein M C , Cotran R S , Braunwald E , Maroko P R
Published: June 2012

The purpose of this study was to determine whether propranolol, which has been shown to reduce the extent of myocardial infarction, reduces microvascular injury which may play a role in exacerbating ischemia. Saline (10 dogs) or propranolol (2 mg/kg i.v., 7 dogs) was injected prior to a one hour occlusion of the left anterior descending coronary artery. Carbon black (1 ml/kg), which labels damaged and leaky vessels, was injected 5 min after release of the occlusion and allowed to circulate for two hours. By morphometric analysis of 1 micron thick sections, 75 +/- 12% of vessels and 84 +/- 7% of myocardial cells showed damage in untreated dogs; only 2 +/- 1% of vessels and 9 +/- 8% of myocardial cells showed damage in the propranolol-treated dogs (P less than 0.001). The number of carbon black-labeled vessels/10 fields/biopsy from comparable areas of ischemic tissue was 55 +/- 7 in untreated dogs and 27 +/- 3 in propranolol-treated dogs (P less than 0.001). The results suggest that propranolol not only protects the ischemic myocardial cell, but also significantly decreases the ischemic microvascular changes.
Electrophysiologic delineation of the specialized atrioventricular conduction system in two patients with corrected transposition of the great arteries in situs inversus (I,D,D).
Authors: Dick M , Van Praagh R , Rudd M , Folkerth T , Castaneda A R
Published: June 2012

Electrophysiologic delineation of the atrioventricular conduction system at surgery is described in two patients with corrected transpostion of the great arteries in situs inversus. Intra-atrial electrograms were recorded in one patient from sites immediately adjacent to the coronary sinus located in the left-sided right atrium. The intraventricular portion of the atrioventricular conduction system was identified in both patients along the posterior and inferior margin of the ventricular septal defect, in contrast to the superior and anterior location found in corrected transposition of the great arteries in situs solitus. In contrast to the superior and anterior location found in corrected transposition of the great arteries in situs solitus. The course of the conduction system in the hearts of these two patients and a possible relationship to the cardiac loop and dual origin of the atrioventricular node is discussed. These cases illustrate the usefulness of segmental diagnosis of congenital heart disease and of electrophysiologic identification of the specialized atrioventricular conduction system at surgery.
Hypercontractile cardiac states simulating hypertrophic cardiomyopathy.
Authors: Come P C , Bulkley B H , Goodman Z D , Hutchins G M , Pitt B , Fortuin N J
Published: June 2012

Hypertrophic cardiomyopathy (HCM) or idiopathic hypertrophic subaortic stenosis (IHSS) has been defined as an autosomal dominant myocardial disease characterized by specific physical findings, echocardiographic features, asymmetric septal hypertrophy and disordered myocardial architecture. Echocardiographic and scintiphotographic studies failed to reveal evidence of asymmetric septal hypertrophy in four patients with systolic anterior movement of the mitral valve and the typical ausculatory and peripheral pulse abnormalities characteristic of HCM. Postmortem examimination in one patient demonstrated mild concentric left ventricular hypertrophy and a normal arrangement of myocardial muscle fibers. These observations in four patients demonstrate that both systolic anterior movement of the mitral valve and the physical findings characteristic of HCM are not specific for the autosomal dominant myocardial disease characterized by asymmetric septal hypertrophy and abnormal septal histology.
Natural history of ventricular septal defect. A study involving 790 cases.
Authors: Corone P , Doyon F , Gaudeau S , Guérin F , Vernant P , Ducam H , Rumeau-Rouquette C , Gaudeul P
Published: June 2012

The development of 790 untreated patients affected by ventricular septal defect (VSD) has been the object of a 25-year study. Of these patients, 72% had had at least one catheterization; 13% had several. The mean observation interval is six years, and the average age at the latest data is 19.5 years. This study covers 4717 patient-years. For the entire population, the incidence rate or aortic regurgitation is 6.3% (4.3 for 1000 patient-years) and that of bacterial endocarditis is 3.7% (2.4 for 1000 patient-years). Twenty-five patients died, 15 of them between the ages of one and 39. Of the 499 cases with several clinical examinations, 71% remained stable. In 21%, changes suggesting some level of closure developed; in 7%, infundibular stenosis began to evolve and in 1% pulmonary vascular disease began to appear or became accentuated. These different rates are studied and discussed in relation to patients' age, VSD type, and various follow-up characteristics.
De subitaneis mortibus. XXIV. Ruptured interventricular septum and heart block.
Authors: James T N
Published: June 2012

Five patients with acute posterior myocardial infarction developed varying degrees of atrioventricular (A-V) block prior to rupture of their interventricular septums (IVS). In three of these five the times of septal rupture coincided with the resumption of conduced synus rhythm. During the period of A-V block, the only stable escape rhythm appeared to originate in the A-V junctional region, and in two patients early in their course there was evidence of enhanced A-V junctional automaticity. Although the A-V node contained extensive infarction in all five hearts, its distal part, and the entire His bundle and proximal branches appeared to be spared. The anatomical pattern of dissection within the ruptured IVS was similar in three hearts, extending upward to the crest of the IVS and penetrating into the interatrial septum in two of these. Multiple major coronary narrowing were present in all five hearts, especially of a dominating right coronary artery; recent thrombosis was present in the right coronary artery in four of the five cases. The A-V node artery was markedly narrowed by focal fibromuscular dysplasia in three hearts, compounding the ischemia for the A-V node and eliminating one important source of collateral circulation to the interventricular septum.
Exercise testing soon after myocardial infarction.
Authors: Markiewicz W , Houston N , DeBusk R F
Published: June 2012

Forty-six men under age 70, without clinical congestive heart failure or unstable angina pectoris, performed treadmill tests 3, 5, 7, 9 and 11 weeks after myocardial infarction. Patients were more frequently able to perform moderate exertion (2 mph, 14% grade) at 7 and 11 weeks than at 3 weeks following infarction. Ischemic ST-segment depression, usually unaccompained by angina pectoris, occurred in 45% of patients and was associated with a significantly increased incidence of subsequent coronary events. The presence of exercise-induced ventricular ectopic activity provided little independent prognostic information. No serious complications occurred in 210 tests. Exercise testing soon after myocardial infarction provides objective information concerning the capacity to resume physical activity, including return to work. Two tests, at 3-5 weeks and at 7-11 weeks, appear to provide most of the information contined in five tests performed during this time.
Location and size of acute transmural myocardial infarction estimated from thallium-201 scintiscans. A clinicopathological study.
Authors: Wackers F J , Becker A E , Samson G , Sokole E B , van der Schoot J B , Vet A J , Lie K I , Durrer D , Wellens H
Published: June 2012

A clinicopathological study was performed in 23 patients who died from acute transmural myocardial infarction and who had been studied with thallium-201 during the acute phase. Twenty patients died within five days and three later than five days after scintigraphy. The scintigraphic location and the estimated size of infarction in vivo were correlated with postmortem findings. There was good agreement in 91% between scintigraphic and postmortem location of infarction and in 70% between the ECG and postmortem findings. The size of infarction as determined from computer-processed schematic drawings of postmortem slices of the heart correlated well with the size determined from processed schematic drawings of the scintiscans (r = 0.91 for anterior infarction, r = 0.97 for inferior infarction, r = 0.86 for anterior-inferior infarction). It is concluded that thallium-201 scintigraphy provided more precise location of infarction than the ECG and that the size of the scintigraphically abnormal area reflected the extent of necrotic myocardium.
Congenital heart block in newborns of mothers with connective tissue disease.
Authors: McCue C M , Mantakas M E , Tingelstad J B , Ruddy S
Published: June 2012

Of 22 children with congenital complete heart block (CCHB) available for study, 14 (63.6%) were born to 11 mothers with clinical or laboratory evidence of connective tissue disease, primarily lupus erythematosus (LE). Seven mothers had both clinical and laboratory evidence of disease while four had only positive laboratory studies including fluorescent antinuclear antibody, rheumatoid factor, and depressed complement levels. In adults with systemic LE, pathologic changes in the collagen surrounding the conduction system have led to the fibrosis and death from heart block. Antinuclear antibodies of the IgG class cross the placental barrier and newborn infants have been reported with transient skin lesions of lupus. Placental transmission of such antibodies may affect the fetal cardiac conduction system, surrounding collagen, and myocardium, leading in some cases to CCHB. This is probably one important etiologic factor in CCHB even though the mother is asymptomatic during her pregnancy.
A critical review of the systolic time intervals.
Authors: Lewis R P , Rittogers S E , Froester W F , Boudoulas H
Published: June 2012

The theoretical basis for the use of the systolic time intervals has been largely established. The method has been validated by direct measures from within the circulatory system. Standards for equipment and technique have been defined. Numerous clinical studies have demonstrated the value of this quantitative noninvasive technique for assessing left ventricular performance. At present there is need for further studies of the clinical usefulness of the systolic time intervals to improve both diagnosis and therapy of various cardiovascular disorders.