Systemic and coronary hemodynamic effects of combined alpha- and beta-adrenergic blockade (labetalol) in normotensive patients with stable angina pectoris and positive exercise stress test responses

Abstract The systemic and coronary hemodynamic effects of combined α- and β-adrenergic blockade produced by labetalol were assessed in 12 normotensive patients with angina pectoris and an ischemic electrocardiographic response to exercise stress. When given to the patient at rest, labetalol (0.5 mg/kg intravenously) produced systemic and coronary vasodilation (mean 16% and 13%, respectively, both p 5 was less after labetalol (from 1.2 to 0.4 mm, p