Systemic and coronary hemodynamic effects of beta-adrenoceptor blocking agents in coronary artery disease.

Systemic and coronary hemodynamic effects of acebutolol (10 mg i.v.), a cardioselective beta-adrenoceptor blocking agent were investigated in 11 patients with coronary artery disease and significant arterial obstructive lesions. Efficacy was assessed by simultaneous left and right heart catheterization and with an inlaying Webster thermodilution catheter in the coronary sinus. The data were compared with data from 7 other patients who received 2 mg i.v. of propranolol, a non-cardioselective beta-blocker. With acebutolol, (1) the heart rate was reduced significantly (p less than 0.001), (2) no significant changes were observed in the LVSP, LVEDP, mean PWP, LVmax dp/dt/p, LV negative dp/dt/p, CI, SWI and SPI, (3) CSF and MVO2 decreased significantly (p less than 0.01) 5 min after injection and (4) the CVR showed a significant elevation (p less than 0.05) after 5 min. With propranolol, (1) the heart rate decreased significantly (p less than 0.05), (2) there were no significant changes in LVSP and LVEDP, (3) the mean PWP increased significantly (p less than 0.05), (4) the LVmax dp/dt/p, CI and SWI decreased significantly (p less than 0.05), (5) the CSF and MVO2 decreased markedly (p less than 0.01) and (6) the CVR increased markedly (p less than 0.01). As compared to the effects of 2 mg i.v. of propranolol, those produced by acebutolol (10 mg i.v.) were characterized by a predominant negative chronotropic action with minimal negative inotropic action, combined with a reduction in CSF and MVO2. The findings suggest that the efficacy of acebutolol in pump failure caused by myocardial ischemia during effort angina is mediated by improvement of the myocardial oxygen demand-supply imbalance.