ISSN:0009-7322    

出版商:OVID    

年代:1978

数据来源: OVID

摘要:

SUMMARYLactic dehydrogenase (LD) isoenzymes were determined by a rapid, simple technique and their utility in the diagnosis of acute myocardial infarction (AMI) was evaluated. LD isoenzymes were separated by ion-exchange column chromatography using DEAE-Sephadex. The cardiac fractions (LD-1 and LD-2) were measured separately on an Abbott ABA-100 analyzer and ratio of LD isoenzyme I to LD isoenzyme 2 (LDI:2) calculated. Daily serum samples were obtained from 100 patients selected only for a history of chest pain of abrupt onset. In 47 patients whose diagnosis was acute myocardial infarction (AMI), confirmed by typical clinical presentation and typical rise in cardiac-specific creatine kinase isoenzyme (MB), peak LD1:2 ranged from 0.77 to 2.26. In 44 patients without AMI, peak LD1:2 ranged from 0.25 to 0.76. In two patients with electrocardiographic changes chest pain occurred two and five days previously; there was no rise in MB, but LD1:2 was elevated. Four patients with small AMI had no rise in LD1:2. Three more patients (one with active hemolysis) had false positive results. Thus, there was a sensitivity of 96% and a specificity of 97% when the cut-off point was LD1:2 = 0.76.LD1:2 is not quite as sensitive or specific as MB, but the ratio allows for the diagnosis of infarction in cases where MB has already returned to normal.

ISSN:0009-7322    

出版商:OVID    

年代:1978

数据来源: OVID

摘要:

SUMMARYThis study examined nonuniform postganglionic cardiac sympathetic neural discharge as a possible mechanism involved in the production of coronary occlusion or ouabain-induced arrhythmias. After acute occlusion of the left anterior descending coronary artery in 12 cats, anesthetized with a-chloralose and pretreated with atropine, arrhythmia occurred within 3 min in eight animals; three of these died in ventricular fibrillation. In recordings from 15 nerves in the eight animals with arrhythmia, spontaneous discharge increased in nine nerves, decreased in five nerves, and showed no change in one nerve. This nonuniform neural discharge was associated with the development of arrhythmia after occlusion. In four of the cats, neural discharge did not change within the first 3 min after coronary artery occlusion and arrhythmia did not occur. Development of ouabaininduced arrhythmia was accompanied by a nonuniform pattern in the neural discharge (13 cats). This discharge may alter ventricular excitation and conduction to produce arrhythmia.

ISSN:0009-7322    

出版商:OVID    

年代:1978

数据来源: OVID

摘要:

SUMMARYMaximum exercise testing using treadmill walking and cycle ergometry was compared in 40 male patients who had suffered a myocardial infarction in the preceding twelve months. Maximum oxygen uptake was on average 17% greater in the treadmill than the cycle test and maximum heart rate was also higher, but the rate pressure product (RPP) was similar due to a higher blood pressure in the cycle ergometer test. Eleven subjects showed STsegment depression greater than 1 mm and eight subjects showed STsegment elevation greater than 1 mm. There was a close relationship ('= 0.96) between the magnitude of ST-segment changes in the two tests. Four subjects showing ST depression of I mm in the, treadmill test showed depression during the cycle ergometer test which was less than this conventionally "positive" value. In these subjects RPP was lower during cycling than in treadmill walking. With both tests maximum ST-segment changes were measured immediately on stopping exercise: resolution of ST depression was more rapid than ST elevation. The two exercise testing modes are closely comparable in their ability to reveal changes of myocardial ischemia.

ISSN:0009-7322    

出版商:OVID    

年代:1978

数据来源: OVID

摘要:

SUMMARYAll 1400 coronary bypass grafts, in 409 survivors of 414 patients undergoing 440 consecutive bypass operations, were selectively opacified in multiplane cineangiograms prior to hospital discharge and 1132 (81%) were restudied at one year. Grafts were graded A (excellent), B (fair) or 0 (occluded) by separate assessment of proximal and distal anastomoses and bypass trunks. In early graft studies 89% were patent (A and B), 79% graded A; at one year, 81% were patent, 74% graded A. Circumflex-marginal grafts fared less well early, but similarly late, compared with other grafts. Of all grafts graded B early, 37% became A, 39% remained B and 24% were occluded at one year; 90% of early graded A grafts remained so, 4% became B and 6% occluded; the grading system seems to have had useful predictive value. Distal anastomosis defects dictated early B grading in 81.3% of cases, trunk defects in 12.5% and proximal anastomosis defects in 2.7%. Trunk defects carried a worse prognosis for occlusion than did distal anastomosis defects. Side-to-side, veincoronary anastomoses had a significantly higher patency rate than terminal end-to-side coronary anastomoses with the same veins.

ISSN:0009-7322    

出版商:OVID    

年代:1978

数据来源: OVID

摘要:

SUMMARYFifty-five patients with recent myocardial infarction and 55 healthy controls, matched for age, sex, race, height, weight, education and job, had an electrocardiogram taken every two months for seven years. Twenty-eight patients and one control had a sudden cardiac death. The QT, (mean of all values recorded) was found prolonged in one control (2%), five of 27 surviving patients (18%) and in 16 of 28 patients who had sudden death (57%). The difference between surviving and sudden death patients is significant (p < 0.01). It is interesting that the only control with a long QT was the one who died suddenly of myocardial infarction. Among patients with previous myocardial infarction a prolonged QT, constitutes a 2.16 times greater risk for sudden death. We conclude that a constant prolongation of QT, in patients with myocardial infarction may help, with other risk factors, in defining a subgroup at higher risk for sudden death.

ISSN:0009-7322    

出版商:OVID    

年代:1978

数据来源: OVID

摘要:

SUMMARYWe measured right and left ventricular ejection fraction (EF) from high frequency time-activity curves obtained during the initial passage of an intravenous bolus of 99mTc (Sn) pyrophosphate. In 22 normal controls right ventricular EF averaged 0.52 ± 0.04 (SD). In 24 acute anterior or lateral infarction patients right ventricular EF was normal (0.56 ± 0.10), while left ventricular EF was reduced (0.45 ± 0.10, P < 0.001 vs controls). In 19 acute inferior infarction patients left ventricular EF also was depressed (0.51 ± 0.09, P < 0.001 vs controls). Among 7 of 19 inferior infarc- tion patients with right ventricular infarction by scintigraphy, right ventricular EF was reduced (0.39 ± 0.05; P < 0.001 vs normals; P < 0.01 vs inferior infarction patients without right ventricular involvement). In the latter group right ventricular EF averaged 0.51 ± 0.10 (NS vs normals). We conclude 1) a single injection of 19mTc (Sn) pyrophosphate can identify right and left ventricular dysfunction and infarct location in acute myocardial infarction, 2) right ventricular EF is well-preserved except when inferior infarction involves the right ventricle.

ISSN:0009-7322    

出版商:OVID    

年代:1978

数据来源: OVID

摘要:

SUMMARYWe correlated clinical parameters with angiographic findings in 108 men with a previous isolated inferior myocardial infarction, to determine if these parameters could predict accurately which patients had multivessel disease.Of 71 men in angina class 2-3, 42 had three vessel disease versus only seven of the 37 who were either asymptomatic or angina class 1 (P < 0.001). Multivessel disease was present in 35 of the 36 who had anterior ST-T abnormalities at rest (P < 0.001) and 16 of the 17 with cardiomegaly. Among men 55 years and older, the incidence of multivessel disease was 94% compared to 70% in men less than 55 (P < 0.03).We conclude that functional angina class, age, and the presence of resting anterior ST and T abnormalities are highly predictive of associated left system disease in survivors of inferior infarction.

ISSN:0009-7322    

出版商:OVID    

年代:1978

数据来源: OVID

摘要:

SUMMARYThe effect of propranolol (0.1 mg/kg intravenously followed by 320 mg given over 27 hour orally) on serum levels of creatine kinase enzyme was studied in a randomized trial involving 95 patients seen within 12 hours of onset of symptoms of uncomplicated myocardial infarction. In 15 patients who were treated with propranolol within 4 hours of onset, and who eventually developed pathological Q waves, peak measured enzyme levels were 27% (P < 0.0125) lower than in 19 control patients who were also seen within 4 hours of the onset but had no specific treatment. Total calculated enzyme appearance was also lower in the treated patients (reduced 25%, P < 0.05) as was the calculated rate of appearance (33%, P < 0.005). No significant difference was found for treated compared with control patients entering the trial more than 4 hours after the onset of chest pain. This evidence suggests that propranolol may reduce the size of uncomplicated infarctiops if it is given intravenously within 4 hours of the onset.

ISSN:0009-7322    

出版商:OVID    

年代:1978

数据来源: OVID

摘要:

SUMMARYIn 58 patients with uncomplicated acute anterior myocardial infarction, a mean decline in the sum of ST segments (EST) of 34% was observed when comparing 1ST values recorded at 3-6 hours with those recorded at 6-9 hours after the onset of symptoms (P < 0.05). The mean absolute difference between 19 paired readings 1-2 hours apart was 2.9 ± 3.0 mm and between 29 readings 2-4 hours apart 3.0 ± 3.0 mm. However, the mean absolute difference between 38 paired readings 4-8 hours apart was 12.2 ± 11.8 mm with a wide range of differences. Left ventricular failure and pericarditis were also associated with significantly higher IST values. We conclude that there is a complex relationship between ST-segment elevation and a number of clinical factors during the first 48 hours after infarction. Nevertheless, precordial mapping remains a useful method for the evaluation of short-term (< 4 hours) therapeutic interventions, if other relevant variables are unaltered and if carefully matched control groups are employed.

ISSN:0009-7322    

出版商:OVID    

年代:1978

数据来源: OVID