摘要:

To test the hypothesis that coronary artery bypass grafting (CABG) is not routinely required in patients undergoing aortic valve replacement (AVR) who have coexistent coronary artery disease (CAD), we compared the results of operation in 55 consecutive symptomatic patients who had CAD and underwent AVR without CABG with results in another 142 patients without CAD who underwent AVR during the same period, and with published results from other centers in which CABG was used in patients with CAD who underwent AVR. Operative mortality was 4% in patients with CAD and 5% in patients without CAD. Late survival was not significantly different between the two groups when analyzed for the entire population (80% survival at 3 years in CAD patients, 82% for non-CAD patients), or for the subgroup of patients with aortic stenosis, aortic regurgitation or aortic stenosis plus regurgitation. Eight patients with CAD (15%) developed recurrent angina after AVR (mean follow-up 43 months); only three patients (6%) required CABG because of medically refractory angina (12–43 months). Operative mortality, operative infarction (9%), recurrent angina and long-term survival in patients with CAD after AVR were similar to those at other centers after AVR plus CABG. These data suggest that preoperative detection of CAD does not necessitate CABG in all patients at the time of AVR.

ISSN:0009-7322    

出版商:OVID    

年代:1981

数据来源: OVID

ISSN:0009-7322    

出版商:OVID    

年代:1981

数据来源: OVID

摘要:

Twenty-three children with valvar or discrete subvalvar aortic stenosis underwent a controlled, progressive bicycle exercise test within 6 months before and 3–30 months after surgery for left ventricular outflow tract obstruction. The patients were divided into three groups according to the preoperative resting gradient of left ventricular to aortic peak systolic pressure: 30–69 mm Hg (group A), 70–99 mm Hg (group B), and ≥ 100 mm Hg (group C). Preoperatively, 19 of 23 patients (83%) developed significant ST depression (≥ 1.0 mm) during exercise, whereas only seven (30%) had abnormal ST depression at rest. Postoperatively, mean exercise-induced ST depression regressed to less than 1 mm in all three groups. In the total population the frequency of ST depression greater than 1 mm was significantly reduced after surgical treatment and mean total work and peak exercise systolic blood pressure were significantly increased within 12 months after surgery. Total work increased significantly in group B within 12 months and in group C within 13–24 months after surgery, but remained unchanged in group A. Peak exercise heart rates were similar before and after surgery in each group. Peak exercise systolic pressures increased after surgery in all three groups, but the mean differences were statistically significant only in group C patients tested 13–24 months after surgery. The results of this study show that exercise testing is useful for quantifying the severity of aortic stenosis and documenting the clinical improvement (or lack thereof) after surgical treatment, and that properly supervised exercise testing can be performed at minimal risk to children with significant aortic stenosis.

ISSN:0009-7322    

出版商:OVID    

年代:1981

数据来源: OVID

摘要:

To determine how arteriolar dilation improves cardiac performance in aortic insufficiency, we evaluated the acute effects of hydralazine in 10 patients with chronic severe aortic insufficiency. Control measurements of intracardiac and intravascular pressures, cardiac output and left ventricular volumes were obtained at cardiac catheterization. Hydralazine, 0.3 mg/kg i.v. (maximal dose 20 mg), was administered and all measurements were repeated 30 minutes later. A reduction in systemic vascular resistance from 1264 to 710 dyn-sec-cm−5was associated with significant increases in forward cardiac index (2.9 to 5.1 I/min/m2) and stroke volume index (37 to 55 ml/M2). Left ventricular end-diastolic pressure was reduced from 19 to 12 mm Hg. There was a significant reduction in mean arterial pressure (88 to 83 mm Hg) and a significant increase in heart rate (81 to 94 beats/min).Regurgitant stroke volume was reduced by more than 10 ml/m2in seven patients and for the group was significantly reduced, from 65 to 53 ml/M2. Regurgitant fraction was reduced in all patients; the overall reduction from 0.64 to 0.48 was highly significant. Ejection fraction increased more than 0.10 in four patients, by 0.08 in an additional patient and for the group increased significantly from 0.50 to 0.57. Left ventricular enddiastolic volume decreased by more than 25 ml/m2in four patients, by 19 ml/m2in an additional patient and was decreased significantly, from 208 to 190 ml/m2, for the group.Arteriolar dilators improve cardiac performance in aortic insufficiency by reducing the amount of aortic regurgitation and, in some patients, by substantially improving systolic pump function. These data suggest a role for arteriolar dilators in the mianagement of selected patients with aortic insufficiency.

ISSN:0009-7322    

出版商:OVID    

年代:1981

数据来源: OVID

摘要:

To assess the clinical efficacy of chronic vasodilator therapy for refractory congestive heart failure, the long-term follow-up (mean 13 months, range 3–30 months) was evaluated in 56 patients treated with hydralazine, usually in combination with nitrates. In the first 6 months, 73% improved subjectively and 59% improved by one or two New York Heart Association classifications; early improvement was usually sustained. Mortality was high, 22% at 6 months and 37% at 12 months, but was significantly lower in patients who had a clinical response to vasodilators (21% in responders vs 55% in nonresponders at 1 year). The only clinical indicator that differentiated responders from nonresponders was the presence or absence of symptomatic progression before initiation of vasodilator therapy. Pulmonary artery pressure, pulmonary capillary wedge (PCW) pressure and stroke work index (SWI) before and during vasodilator therapy correlated with clinical response and survival. Fifteen of 20 patients with PCW < 20 mm Hg and SWI ≥ 30 g-m/m2improved and survived, compared with two of 19 with PCW ≥ 20 mm Hg and SWI < 30 g-m/m2. Patients who did not have acute hemodynamic improvement generally did not improve clinically, but neither the percentage change nor the absolute change in any hemodynamic variable predicted outcome in the remaining patients.The findings of this study indicate that vasodilators produce clinical improvement in many patients with refractory heart failure and that hemodynamic measurements are helpful in predicting the outcome of therapy.

ISSN:0009-7322    

出版商:OVID    

年代:1981

数据来源: OVID

摘要:

Data in animals indicate that large amounts of digitalis potentiate arterial baroreflexes and that this factor may be important for the cardiovascular effects of the drug. To determine if arterial baroreflex potentiation also exists after administration of therapeutic doses of digitalis in man, we studied how stimulation and deactivation of arterial baroreceptors by phenylephrine and nitroglycerin injection affect heart rate and how stimulation and deactivation of carotid baroreceptors by neck suction and pressure affects blood pressure and heart rate. The study was performed in 29 normotensive or hypertensive subjects before and after injection of Lanatoside C (0.8 mg i.v.). Baroreceptor stimulation reduced heart rate and blood pressure, while baroreceptor deactivation increased both of these variables. The bradycardic and hypotensive effect of baroreceptor stimulation increased significantly after digitalis both in normotensive and hypertensive subjects. However, the tachycardic and hypertensive responses to baroreceptor deactivation were not affected by digitalis. Thus, therapeutic doses of digitalis in man enhance baroreceptor reflexes, and both the heart rate and the blood pressure reflex effects are involved. However, the enhancement occurs to a marked degree only with baroreceptor stimulation and is not evident with baroreceptor deactivation.

ISSN:0009-7322    

出版商:OVID    

年代:1981

数据来源: OVID

摘要:

To determine if the severity of angina pectoris and the degree of altered left ventricular function correlated with the severity and extent of the underlying coronary artery disease, a coronary scoring system was derived. The system was based on the severity of luminal diameter narrowing and weighted according to the usual flow to the left ventricle in each coronary vessel. Thus, the most weight was given to the left main coronary artery, followed by the left anterior descending, circumflex, and right coronary arteries. The resultant number was an indicator of the overall severity of the obstructive coronary artery disease. A coronary arterial system with no obstructive disease was scored as zero and the greater the degree of obstructive disease present, the higher the coronary score. From 202 subjects, four groups were evaluated: group 1—coronary score = 0.5–4.5 (n = 10); group 2—coronary score = 10.5–12.5 (n = 11); group 3—coronary score = 17.5–20.5 (n = 11); and group 4—coronary score = 25.0–36.0 (n = 11). All subjects had coronary artery bypass surgery and had preoperative and l-year postoperative cardiac catheterization, including atrial pacing to maximal heart rate. The groups could not be separated on the basis of angina frequency, resting heart rate, cardiac index, left ventricular end-diastolic pressure, peak paced left ventricular end-diastolic pressure, dP/dt, V max, left ventricular end-diastolic volume index, left ventricular end-systolic volume index, stroke volume index, ejection fraction or mean circumferential fiber shortening velocity. Thus, based on this study, the severity of coronary artery disease does not statistically correlate with the frequency of angina pectoris or produce a predictable degree of altered left ventricular function. The frequency of angina pectoris cannot be used to predict prognosis orthe adequacy of myocardial revascularization.

ISSN:0009-7322    

出版商:OVID    

年代:1981

数据来源: OVID

摘要:

Stepwise linear discrimination was used to analyze risk factors in 431 consecutive patients who underwent coronary angiography to determine which variables were most closely associated with coronary artery disease. Twenty-one risk factors were considered: total plasma cholesterol and triglycerides; the cholesterol and triglyceride content of high-density lipoproteins (HDL), low-density lipoproteins (LDL) and very low density lipoproteins (VLDL); and the percentage of total cholesterol and triglycerides in each fraction. Age, smoking history, family history, hypertension, diabetes mellitus and relative weight were also considered. Coronary artery disease was assessed using three standard grading scores. There were significant differences in risk factors between males and females. In males, LDL cholesterol and age were selected by multivariate analysis. In females, the ratio of HDL cholesterol to total cholesterol, as well as relative weight, family history, age and smoking were selected. The discriminating value of HDL cholesterol as the percentage of total cholesterol was significantly greater than that of HDL cholesterol itself. Despite highly significant associations between risk factors and the presence of coronary artery disease, the discrimination did not provide sufficient separation of the groups to give results that are useful diagnostically in individual patients.

ISSN:0009-7322    

出版商:OVID    

年代:1981

数据来源: OVID

摘要:

In 19 patients with unstable angina pectoris at rest, plasma levels of the platelet-derived proteins β-thromboglobulin and platelet factor 4 were significantly elevated in blood samples obtained during or within 4 hours after episodes of angina, but were usually normal during quiescent intervals. Plasma levels of the arachidonic acid metabolite thromboxane B2were less clearly related to angina, and there was no association of angina with levels of the coagulation product fibrinopeptide A. This demonstration of an association of platelet activation and secretion with unstable angina pectoris by radioimmunoassay of circulating platelet constituents offers a new approach to assessment of therapy in ischemic heart disease and suggests that agents that alter platelet function should be evaluated in patients with unstable angina.

ISSN:0009-7322    

出版商:OVID    

年代:1981

数据来源: OVID

摘要:

Streptokinase was infused into the ischemia-related coronary artery at a rate of 1000–2000 U/min for 15–95 minutes in 29 patients with acute myocardial infarction(AMI group) and in five patients with unstable angina pectoris (UAP group). Reopening of the completely obstructed vessel or increase of diameter at the site of subtotal lesions occurred in 22 AMI patients within 15–90 minutes of streptokinase infusion. In four of these patients, antegrade flow to the distal segments of the infarct vessel was seen after intracoronary nitroglycerin or sublingual nifedipine administration, which preceded streptoklinase infusion, and in two patients, streptokinase infusion was combined with recanalization by means of a guide wire. Chest pain was alleviated after reperfusion; ejection fraction was 50.5 ± 12% before and 54.6 ± 9% immediately after successful intracoronary lysis (p< 0.05). Repeat angiography, performed 25 ± 11 days after the acute intervention in 19 AMI patients, revealed reocclusion of the infarct vessel in one patient. Aortocoronary bypass surgery was performed electively in six AMI patients at varying intervals after successful lysis. Upon intraoperative inspection, the bulk of myocardium perfused by the recanalized vessel was found to be viable.Intracoronary streptokinase infusion did not result in opening the complete obstruction or improvement of lumen at the site of subtotal lesions in seven AMI patients and in all UAP patients. The total dose of 128,000 ± 36,000 U of streptokinase resulted in only minor decrease of fibrinogen, from 451 ± 93 mg% to 430 ± 91 mg%. Bleeding from the arterial puncture site in two patients, the only complications that could be attributed to the procedure, was due to heparinization.Intracoronary streptokinase application appears to be a safe and efficient method of achieving reperfusion and alleviating ischemia in the majority of patients with acute myocardial infarction. The method was not beneficial in treating unstable angina pectoris, and its potential for salvage of myocardium is yet to be assessed.

ISSN:0009-7322    

出版商:OVID    

年代:1981

数据来源: OVID