摘要:

Of 2144 patients age 65 years or older entered into the registry of the Coronary Artery Surgery Study (CASS) who had coronary arteriography, 1086 underwent isolated coronary artery bypass grafting. Complications of angiography included death in four patients and nonfatal myocardial infarction in 17. Eight patients suffered neurologic complications, which were transient in five. The perioperative mortality was 5.2% (57 of 1086), which is significantly greater than the perioperative mortality of 1.9% 151 of 7827) in patients younger than 65 years entered in CASS (p < 0.001). There was a trend toward an increased mortality rate with age; it was 4.6% (37 of 803) in patients age 65–69 years, 6.6% (16 of 241) in those 70–74 years and 9.5% (four of 42) in those 75 years or older. The duration of hospital stay after operation was significantly longer for the patients 65 years or older than for the patients younger than 65 13.3 vs 11.4 days; p < 0.001). Stepwise linear discriminant analysis identified five variables predictive of perioperative mortality: presence of 70% or more stenosis of the left main coronary artery and a leftdominant circulation, left ventricular end-diastolic pressure, a history of current cigarette smoking, pulmonary rales on auscultation, and presence of one or more associated medical diseases. A second linear discriminant analysis, incorporating 7658 CASS patients who underwent isolated coronary artery bypass surgery irrespective of age, examined whether age 65 years or older was an independent predictor of perioperative mortality. The variables selected, in order of significance, were congestive cardiac failure score, left main coronary artery stenosis and a left-dominant circulation, age 65 years or older, left ventricular wall motion score, sex and history of unstable angina pectoris. In patients 65 years or older, the mortality from coronary arteriography is low, whereas mortality from coronary artery bypass surgery is greater than that in CASS patients than 65

ISSN:0009-7322    

出版商:OVID    

年代:1983

数据来源: OVID

摘要:

Supported in part by a grant from the Medical Council of the Academy of Finland. Address for correpondence: M. Heikki Frick, M.D., First Departmentof Medicine, University Central Hospital, SF-00290 Helsinki 29, Finland. Received February 4, 1982; revision accepted September 28, 1982.

ISSN:0009-7322    

出版商:OVID    

年代:1983

数据来源: OVID

摘要:

In 526 patients undergoing a first percutaneous transluminal coronary angioplasty (PTCA) of a single native vessel, we studied the influence of length and eccentricity of the lesion on complications and primary success. Long stenoses (3a 5 mm, n = 153) did not differ from short stenoses (S 4 mm, n = 265) in terms of overall complications or gain in lumen diameter and distal pressure. Eccentric stenoses (n = 155) showed a lower rate of primary success than concentric stenoses (n = 338) (80% vs 89%, p < 0.05). Inability to cross the stenosis was the main reason for failure. Stenoses that were long and eccentric (n = 51) had the highest incidence of complications (24%) and stenoses that were short and concentric (n = 177) the lowest (12%, p < 0.05). However, the average outcome expressed by gain in lumen diameter and distal pressure was equal in both groups and is obviously more dependent on technical factors than on anatomy. Nevertheless, length and, particularly, eccentricity of a lesion constitute risk factors for PTCA. They may be overcome by technical skill and sophisticated equipment, such as steerable catheters.

ISSN:0009-7322    

出版商:OVID    

年代:1983

数据来源: OVID

摘要:

This study was designed to clarify discrepancies in the literature concerning platelet survival time and,/-thromboglobulin (I3TG) levels in patients with coronary artery disease (CAD) and the effect of platelet-suppressant drugs on these tests. Platelet survival time and plasma,/TG levels were determined in 48 patients with angiographically documented CAD. The effect of sulfinpyrazone or aspirin/dipyridamole on these measurements was investigated in a double-blind, crossover trial that included a placebo phase. In patients with CAD, the mean plasma, BTG concentration was significantly elevated, but the mean platelet survival time was not significantly different from that in controls. Treatment with sulfinpyrazone or aspirin/dipyridamole did not produce changes in platelet survival time or plasma,3TG concentration that were significantly different from the values during the placebo phase. This study demonstrates th'at compared with the spontaneous variation in platelet survival time or ITG concentration, there was no measurable effect of sulfinpyrazone or aspirin/dipyridamole on the results of the tests.

ISSN:0009-7322    

出版商:OVID    

年代:1983

数据来源: OVID

摘要:

Epidemiologic and experimental data suggest an antiatherothrombotic potential of c-3 polunsaturated fatty acids. Therefore, the Western diet, which supplies predominantly w-6 polyunsaturated fatty acids, was supplemented with 40 ml/day of cod liver oil, which provides about 10 g of co-3 polyunsaturated fatty acids daily, for 25 days in eight volunteers. The w-3 polyunsaturated fatty acids were incorporated in platelet and erythrocyte membrane phospholipids at the expense of w-6 polyunsaturated fatty acids. Bleeding time increased (p < 0.01) and platelet count (p < 0.05), platelet aggregation upon ADP and collagen (p < 0.01–0.05), and associated thromboxane B2 formation (p < 0.01) decreased. Blood pressure (p < 0.05) and blood pressure response to norepinephrine (p < 0.01) and angiotensin II (NS) fell, without major changes in plasma catecholamines, renin, urinary aldosterone, kallikrein, prostaglandins E2 and F2, and red cell cation fluxes. Biochemical and functional changes were reversed 4 weeks after cod liver oil was discontinued. Formation of prostaglandins derived from eicosapentaenoic acid and interference of eicosapentaenoic acid with formation and action of prostaglandins derived from arachidonic acid were evident in vitro. Whatever the mechanism, this moderate supplement of w-3 polyunsaturated fatty acids markedly changed membrane phospholipids, which was associated with a shift toward less reactive platelets and a blunted circulatory response to pressure hormones.

ISSN:0009-7322    

出版商:OVID    

年代:1983

数据来源: OVID

摘要:

The association of habitual physical activity with plasma high-density lipoprotein (HDL)cholesterol and total triglyceride (TG) was examined in 7106 asymptomatic 35–59-year-old white men withprimary type II hyperlipoproteinemia who attended the second screening visit of the Lipid Research ClinicsCoronary Primary Prevention Trial. Subjects were rated by usual level of physical activity at work andoutside of work and the frequency of strenuous physical labor or exercise. By each of these three criteria, physical activity was monotonically related to HDL cholesterol and TG: the most physically active men hadthe highest HDL cholesterol and lowest TG levels. With respect to physical activity outside of work, forexample, mean HDL cholesterol and TG were 46.4 and 152.1 mg/dl, respectively, in the most active group, and 41.4 and 186.7 mg/dl in the most sedentary group. Physical activity remained significantly predictiveHDL cholesterol and TG when other known correlates of these plasma constituents age, Quetelet index, plasma total cholesterol, cigarette smoking, alcohol intake, and clinic were controlled individuallytwo-way analyses of variance or jointly by analysis of covariance. The association of physical activity withvery low density lipoprotein cholesterol was parallel to but weaker than its association with TG. Lowdensity lipoprotein and total cholesterol were not significantly related to physical activity.

ISSN:0009-7322    

出版商:OVID    

年代:1983

数据来源: OVID

摘要:

Left ventricular pressure (LVP) decay and early diastolic pressures were studied at rest and during exercise in three groups of patients. Patients in the ischemia group (n = 15) had coronary artery disease and developed new regional wall motion abnormalities documented by biplane LV cineangiography during exercise. Patients in the control group (n = 4) had a normal exercise response. Patients in the scar group (n = 5) had prior. infarction, akinetic scars and no ischemia with exercise. Isovolumic pressure data were. used to compute the time constant (T) of LVP decay (from the linear relation of LVP and negative dP/dt) and an extrapolated baseline pressure (PB) at dP/dt = 0. During exercise in the ischemia group, minimal LV diastolic pressure (PL) increased from 9 + 3 to 21 ± 5 mm Hg (p < 0.001), end-systolic volume increased from 38 7 to 55 ± 8 ml/m2 (p < 0.001) and PB rose from -10 ± 7 to 11 ± 8 mm Hg (p< 0.001); T decreased (from 55 ± 9 to 37 ± 8 msec, p < 0.001), although inadequately, compared with the decrease in the control group (from 49 ± 15 to 22 ± 2 msec, p < 0.01). Relaxation at PL during exercise was incomplete in the ischemia group (2.2 ± 0.4 T) and complete in the control group (3.8 ± 0.7 T, p < 0.05). The time course of LVP fall was extrapolated from the isovolumic period into the passive LV filling phase. The extrapolated pressure at the time PL occurred (PE) rose from 0 ± 4 to 20 ± 7 mm Hg with ischemia (p < 0.001). Thus, the characteristics of LVP decay can account for the elevated early diastolic pressures during ischemia. In contrast, the scar group maintained a low PL during exercise (11 3 to 8 ± 3 mm Hg), even though T decreased inadequately (from 66 ± 10 to 36 ± 5 msec, p < 0.01), because PB did not shift upward. Ischemia-related pressure elevations involve both delayed relaxation and a pressure baseline shift. During exercise, LVP decay is normally adjusted to maintain low diastolic pressures; with exerciseinduced ischemia, LVP decay is abnormal and early diastolic pressures are severely elevated.

ISSN:0009-7322    

出版商:OVID    

年代:1983

数据来源: OVID

摘要:

Exercise generally aggravates ischemic myocardial dysfunction, presumably by increasing tissue oxygen demand out of proportion to the increase in supply. Nevertheless, resting left ventricular (LV) wall motion abnormalities can improve dramatically after upright exercise. To investigate this “paradoxical” phenomenon, we performed upright bicycle exercise equilibrium radionuclide ventriculography in 93 patients with angiographic coronary artery disease. Immediately after exercise, LV end-diastolic volume was similar to the resting level (1 + 22% of rest value), but end-systolic volume (ESV) was significantly below (p < 0.05) that at rest (-11 32%) and LVejection fraction increased significantly compared with rest (0.57 ± 0.16 vs 0.51 ± 0.13, p < 0.05). Improvement in resting myocardial asynergy was frequent (115 of 330 abnormal segments), and was observed more commonly in patients without pathologic Q waves and in segments manifesting mild rather than severe asynergy. In 60 additional patients with resting asynergy who were also studied after nitroglycerin (NTG), there was 89% concordance of wall motion response in asynergic segments after exercise and NTG: 71 of 85 segments manifesting improvement with NTG also improved after exercise, and 157 of 172 segments without improvement with NTG also failed to improve after exercise.Despite the similar wall motion response, the mechanism of improvement is probably different from that produced by NTG. With NTG, preload (end-diastolic volume) and afterload (systolic blood pressure) were significantly lower than their resting control levels (p < 0.05). These changes did not occur after exercise. Instead, an isolated, significant reduction in ESV was noted. These data support the hypothesis that catecholamine stimulation is responsible for paradoxical wall motion improvement after upright exercise.

ISSN:0009-7322    

出版商:OVID    

年代:1983

数据来源: OVID

摘要:

Short-term i.v. infusion of streptokinase was performed in 93 patients within 6 hours after the onset of acute myocardial infarction. Twenty-six patients underwent angiography in the acute phase (group A) and 52 underwent angiography in the fourth week only (group B); 15 patients had no angiography. Seven patients died during the hospital stay and six suffered nonfatal reinfarctions. There were no bleeding complications. In 11 of 21 group A patients, occluded coronary arteries were opened within 1 hour after the streptokinase infusion was started. In 84% of groups A and B, the infarct-related coronary artery was patent in the fourth week. In 75% of the patent arteries, the residual luminal diameter stenosis was less than 70%. According to serial serum CK-MB curves, recanalization was achieved mostly within 1–2 hours. Myocardial salvage was indicated by improvement in local contraction disorders in the recanalized group A patients and by the significant relationship between infarct size and time from symptom onset to treatment in group B. These data suggest that a high-dose, short-term, i.v. infusion of streptokinase is a safe and efficient method of restoring coronary blood flow. Expeditious initiation of i.v. streptokinase infusion is a critical determinant for early recanalization and salvage of myocardium. Patients with thrombotically subtotal occlusion probably receive the most benefit. Evaluation of the true impact on survival and myocardial function will require controlled clinical trials.

ISSN:0009-7322    

出版商:OVID    

年代:1983

数据来源: OVID

摘要:

We compared myocardial infarct size produced by permanent occlusion of the middle left anterior descending (LAD) or circumflex (LCx) coronary artery in the anesthetized dog. The dogs were killed 3–10 days later, and the occluded coronary bed was visualized by postmortem arteriography. The outlines of the infarct and occluded bed were marked on tracings of weighed left ventricular (LV) rings and the size of the infarct and occluded bed was calculated by planimetry. For both arteries, infarct size and occluded bed size were linearly related to each other, but LAD infarcts were larger relative to occluded bed size (52.0% vs 32.3%, p < 0.05). A smaller occluded bed was necessary for the appearance of an infarct after LAD occlusion than after LCx occlusion (8.3% vs 18.5% of the left ventricle, p < 0.005). Reconstructed LV ring maps indicated a significantly wider margin of noninfarcted myocardium at the lateral edge of the occluded bed for LCx infarcts than for LAD infarcts. For dogs with similar occluded bed sizes in the range of 20–35% of the left ventricle, infarct size was considerably larger for LAD occlusion (15.9% vs 6.1% of the left ventricle, p < 0.001). In this subgroup, blood pressure and heart rate 10–20 minutes after occlusion were not significantly different for the two arteries, but collateral flow, measured with 9-, u radioactive microspheres, was approximately 50% lower after LAD occlusion. The relationship between the amount of myocardium with reduced blood flow and developed infarct size was similar for the two arteries. We conclude that occlusions of the middle LAD and LCx are not equivalent. For a given occluded bed size, LAD occlusions produce larger areas of infarction, apparently related to lower levels of collateral flow delivered to the occluded region.

ISSN:0009-7322    

出版商:OVID    

年代:1983

数据来源: OVID