摘要:

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 rheumatic fever, and 58% had an illness compatible with acute rheumatic fever at any time.

ISSN:0009-7322    

出版商:OVID    

年代:1977

数据来源: OVID

摘要:

Thirty-eight adults with valvular and/or myocardial disease had heart catheterization with coronary blood flow and myocardial 02 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.

ISSN:0009-7322    

出版商:OVID    

年代:1977

数据来源: OVID

摘要:

Electrophysiologic studies were performed in 32 patients with angiographically documented coronary artery disease (CAD). Group I was composed of ten patients (31%) with severe stenosis (_ 75%) proximal to the origin of the sinus node artery (SNA); group II was composed of five patients (16%) with moderate (50-75%) proximal stenosis; and group III was composed of 17 patients (53%) with insignificant (0-50%) proximal stenosis. The mean sinoatrial conduction time (SACT) for group I was 119 ± 18 msec; group II was 84 ± 16 msec; and group III was 72 ± 5 msec. The SACT was significantly longer in group I than in group III (P< 0.005). In conclusion 1) in patients with CAD, SACT > 72 ± 5 msec abnormal; 2) the results suggest a pathogenetic role of CAD in the development of sinus node dysfunction; 3) the SACT is a more sensitive indicator of subtle sinus node dysfunction in CAD patients than heart rate, sinus node response to atrial extrastimuli, or sinus node recovery time; and 4) the ability to diagnose sinus node dysfunction its early stages and recognition that coronary artery disease is etiologic factor may allow for the elucidation of the natural history of the sick sinus syndrome.

ISSN:0009-7322    

出版商:OVID    

年代:1977

数据来源: OVID

摘要:

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 phases 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.

ISSN:0009-7322    

出版商:OVID    

年代:1977

数据来源: OVID

摘要:

Six new cases of acute myocardial infarction with normal coronary arteriogram are presented and supplemented by 19 collected cases (group 1). These are compared with 16 cases of myocardial infarction caused by occlusive coronary artery disease in a comparable population (group ii). The following significant differences between the two groups are established: patients in group I were younger (27.5 years vs 33.7 years, P > 0.005); at least one risk factor was present in all patients in group II, but in only 40% of group I (P< 0.0001). effort angina preceded the attack in ten patients of group II, but in none of group I (P< 0.0001). The attack was unheralded in 24 of the 25 patients in group 1, but was preceded by prodromes in 11 of 16 in group II (P< 0.0001). Attacks of pain following myocardial infarction occurred in five patients of group I and 11 of group I1 (P< 0.001). Results are discussed in the light of the nature of myocardial infarction in group 1. No support is found for the coronary spasm theory. The most likely mechanism for development of myocardial infarction in group I is thought to be a thromboembolic “accident.” This accident is not necessarily related to atherosclerotic coronary disease and is presumed to be benign in nature.

ISSN:0009-7322    

出版商:OVID    

年代:1977

数据来源: OVID

摘要:

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 doses of verapamil were even more effective in limiting cardiac necrosis despite the development of hypotension and varying degrees of heart block.

ISSN:0009-7322    

出版商:OVID    

年代:1977

数据来源: OVID

摘要:

Methylprednisolone sodium succinate (50 mg/kg) was given 30 minutes before or after the start of a 90 minute occlusion of the left circumflex coronary artery (LCX) in one group of dogs. In a second group, methylprednisolone sodium succinate was given 15 minutes after permanent occlusion of the left anterior descending artery (LAD). Infarct size was determined by dehydrogenase staining after 24 or 96 hours. Heart slices were incubated with nitro-blue tetrazolium and nonstaining infarcted tissue was dissected and weighed. Myocardial depletion of creatine phosphokinase activity (CPK) and lactate dehydrogenase activity (LDH) were determined 24 hours after temporary LCX occlusion. When measured after 24 hours, methylprednisolone sodium succinate treatment did not reduce infarct size or decrease enzyme loss. After temporary LCX occlusion infarct size was 30.4 ± 3.6% of left ventricular weight in control dogs and 30.0 ± 2.3% in treated dogs. No significant difference in infarct size was observed in hearts examined 24 or 96 hours after myocardial infarction. After permanent LAD occlusion, infarct size in control dogs was 39.2 ± 1.6% of left ventricular weight and 33.7 ± 3.5% in treated dogs. CPK activity in the LCX area decreased by 26.5 ± 7% in controls and by 28.1 ± 7% in treated dogs. LDH activity decreased by 26.4 ± 7% in controls and by 30.7 ± 7% in treated dogs. Treated dogs sustained a significantly greater fall in arterial blood pressure after LCX occlusion than did controls. During LCX occlusion and upon reperfusion, methylprednisolone sodium succinate treated dogs exhibited a significantly greater number of premature ventricular beats. Since infarct size and enzyme depletion were not reduced when measured after 24 hours, methylprednisolone sodium succinate treatment does not appear to have enhanced myocardial cell viability.

ISSN:0009-7322    

出版商:OVID    

年代:1977

数据来源: OVID

摘要:

Physiologic changes in the circulatory system caused by performing the Valsalva maneuver are blunted or absent in patients with congestive heart failure. Previously there has been no noninvasive method for examining cardiac chamber size during this maneuver. M-mode echocardiography was used to evaluate possible changes in cardiac chamber dimensions in 12 normal subjects (group I) and 15 patients with cardiovascular disease (group II). In group I, the left ventricular end-diastolic dimension decreased 11.2% (±1.5%) and the end-systolic dimension 9.5% (±1.32%), with a fall in stroke volume of 29%. The left atrial (LA) dimension decreased 30%. In group II, only the response of the LA dimension is reported. There was a diminished response to Valsalva related to the severity of congestive heart failure. Patients in NYHA classes III and IV decreased LA dimension by only 3.8%, significantly less (P< 0.001) than those in classes I and II who had essentially normal responses. Echocardiographically-determined changes in left atrial size in response to the Valsalva maneuver may provide an objective, noninvasive means of evaluating and following patients with suspected or proven congestive heart failure. Possible mechanisms for the changes observed are discussed.

ISSN:0009-7322    

出版商:OVID    

年代:1977

数据来源: OVID

摘要:

Echographic aortic valve closure was compared to the dicrotic notch of the aortic pressure and intracardiac A2 to define the exact temporal relationship of the echographic, pressure, and sound parameters of aortic valve closure. Sixteen children, ages 3-20 years, were evaluated by simultaneous aortic valve echograms, micro-manometric aortic root pressure tracings, and intracardiac phonocardiograms recorded at paper speeds of 200 mm/sec. Our observations demonstrated that echographic coaptation of the aortic valve leaflets coincides with the trough of the aortic pressure incisura and the onset of A2. The data suggest that A2 is a result of valve closure.

ISSN:0009-7322    

出版商:OVID    

年代:1977

数据来源: OVID

摘要:

Edcocardiographic suprasternal relats of the transverse aortic arch (TAA), right piumonary artery (RPA) and left atrium (Y' LAD) were validated and angi p e d measirement correlations were made for each stncture. Normal vaues were detennined with respect to body surface area. In normals, reardes of age or body size, mean dimsional TAA/RPA ratio was 1.2:1 and Y' LAD equaled the anterior-posterior, or Z axis, left atrial dimei (Z LAD). TAA/RPA ratio was inrased in aortic stenosis tetralogy of Fallot and was decreased in ventricular septal defect, atrial septa] defect and pulmonary stenosis. Ratio did not correlate with lesion severity as assessed by cardiac catheterization except in pul_monry stenosis. Discrepant Y' LAD values (usually increased Y' LAD and deceased Z LAD) occurred in children with various fonrs of heart disease. Some had seral compression but others had normal chests. Children with pectus excavatum showed similar compression.These findings underscore the need for ncorporain of a examination into the standard ec rdiographic exainon of cildren.

ISSN:0009-7322    

出版商:OVID    

年代:1977

数据来源: OVID