Effects of Enalaprilat on Regional Wall Stress in Patients with Angina Pectoris.

Left ventricle (LV) cineventriculograms silhouettes in the right anterior oblique projection with simultaneous pressure micromanometry were assessed before and 10 min after administration of 1.25 mg enalaprilat intravenously to 10 patients with angina pectoris undergoing diagnostic cardiac catheterization. Cineventriculograms were divided into 20 areas using a modified Leighton's method for segmentalization of the LV and computed by the Janz's method for regional wall stress. Enalaprilat reduced preload and afterload in all cases. There was significant reduction in regional wall stress in 15 of the 20 segments after enalaprilat administration compared with baseline analysis. Segments without significant reduction in wall stress wee apical. There was significant reduction in global wall stress after enalaprilat. Thus, enalaprilat, in addition to improve hemodynamics decreasing both preload and afterload, reduces LV wall stress both regional and global. Clinical implications of these findings are in agreement with the wall stress reduction for prevention of ventricular remodeling with this agent in postinfarction patients.

Readmission in unstable angina

To determine the characteristics of patients re-admitted after unstable angina (UA) pectoris, 120 consecutive patients hospitalized due to primary UA pectoris were prospectively studied 22 +/- 3 months after discharge. The patients were grouped based on the readmission rate. Those in group A (50) had recurrent admissions (mean 2.6, range 2 to 5). Seventy patients (group B) did not have readmissions during the follow-up period. All patients underwent coronary angiogram and symptoms-limited exercise stress test before discharge. The univariate characteristics for readmission were: age over 70 years (p = 0.02), nondiagnostic exercise stress testing (p = 0.03), angiographically diffuse coronary artery disease (p = 0.004), and non-interventional management (P < 0.001). Patients readmitted had increased incidence of myocardial infarction (p = 0.004) but similar survival at 2 years. By regression analysis, important variables for readmission were non-interventional management (Chi-Square = 7.6, p = 0.01), non diagnostic treadmill test (Chi-Square = 6.9, p = 0.03) and diffuse coronary artery disease (Chi-Square = 6.2, p = 0.04). It is concluded that in the interventional era the most important factor for readmission after primary UA pectoris is non-interventional management. Coronary revascularization should not be denied solely on the basis of age

Dose-Related Hemodynamic Effects of Enalaprilat in Patients with Ischemic Heart Disease.

To investigate the dose-related hemodynamic effects of angiotensin-converting enzyme inhibition (ACEI) in patients with angina pectoris (AP), five patients underwent right and left heart catheterization, and left ventriculogram before and 10 min after administration of 1.25 mg enalaprilat intravenously (Group 1). The results were compared with those of five patients with similar characteristics who received 2.5 enalaprilat (Group 2). There were no baseline differences between groups. After enalaprilat administration, there was significant differences between Groups 1 and 2, as follows: systolic blood pressure was 138 plus minus 16 versus 127 plus minus 14 mmHg (p = 0.05), left ventricular end-diastolic pressure was 15 plus minus 6 versus 7 plus minus 4 mmHg (p = 0.04), systemic vascular resistance was 1341 plus minus 290 versus 965 plus minus 271 dyne/sec/cm(minus sign5) (p = 0.05), pulmonary vascular resistance was 174 plus minus 39 versus 156 plus minus 15 dyne/sec/cm(minus sign5) (p = 0.05), end-diastolic volume was 87 plus minus 34 versus 107 plus minus 17 ml (p = 0.03), cardiac index was 3.0 versus 4.5 L min(minus sign1) m(minus sign2) (p = 0.01), left ventricle end-systolic wall stress was 31 plus minus 10 versus 22 plus minus 9 k dyne cm(minus sign5) (p = 0.01), ejection fraction was 69 plus minus 12 versus 81 plus minus 8% (p = 0.01), and wall motion index was 1.14 plus minus 0.1 versus 1.02 plus minus 0.1 (p = 0.001). These results indicate that enalaprilat has dose-related effects improving hemodynamics and ventricular function in patient with AP.

Electrophysiologic Changes in the Human Heart Produced by Enalaprilat (Angiotensin-Converting Enzyme Inhibitor).

Several trials have showed that angiotensin-converting enzyme inhibitors possess some extent of antiarrhythmic properties. To evaluate the effects of Enalaprilat on His bundle recording, patients undergoing diagnostic coronary angiogram due to angina pectoris and a positive thallium exercise test subsequently underwent His bundle electrogram. A double-blind crossover protocol was used with conduction velocity measurements at baseline and after saline (placebo) and Enalaprilat 2.5 mg intravenously. There were no significant changes in heart rate (64 plus minus 9 versus 65 plus minus 11 versus 65 plus minus to beats min(minus sign1)) at baseline, after saline and enalaprilat infusion, respectively, mean blood pressure (97 plus minus 11 versus 94 plus minus 10 versus 94 plus minus 7 mm Hg, respectively), atrioventricular conduction time (100 plus minus 20 versus 100 plus minus versus 100 plus minus 20 versus 100 plus minus ms), and His--Purkinje (HV) conduction time (40 plus minus 12 versus 40 plus minus 13 versus 40 plus minus 12 ms). Ventricular activity duration was 110 plus minus 11 ms at baseline, 110 plus minus 10 ms after saline infusion (p = NS), and 88 plus minus 13 ms after Enalaprilat administration (p < 0.001). Angiotensin-converting enzyme inhibition appears to produce significant reduction in ventricular activity duration (increase in intraventricular conduction velocity).