The effects on left ventricular performance of verapamil and metoprolol singly and together in exercise-induced angina pectoris.
Concurrent therapy with the calcium channel blocker, verapamil, and the beta-blocking group of compounds is usually felt to be clinically contraindicated due to the former's potent dromotropic and negative inotropic actions. The basis of this assumption was examined in a rest and exercise hemodynamic study of the effects of verapamil and the cardioselective beta-blocking drug, metoprolol, in 22 patients with stable angina pectoris and angiographically confirmed coronary artery disease. In a randomized study, 11 patients were assessed following intravenous verapamil (16 mg) alone, 11 following intravenous metoprolol (10 mg) alone, and all 22 were assessed on combination therapy. The plasma levels achieved at the time of each hemodynamic assessment were in the therapeutic range. At rest, verapamil alone significantly lowered systemic arterial pressure and vascular resistance; metoprolol alone lowered heart rate and increased systemic vascular resistance without change in systemic arterial pressure. Combination therapy reduced systemic arterial pressure and heart rate without change in cardiac output and systemic vascular resistance. During upright bicycle exercise, the changes were directionally similar. Depression of cardiac function (i.e., reduced cardiac output at increased pulmonary artery occluded pressure) occurred following metoprolol but not following verapamil; the addition of verapamil did not accentuate the depression of function induced by metoprolol. These results suggested that in patients with stable coronary artery disease, without manifest conduction system abnormality, the cardiac depressant actions of verapamil were countered by its vasodilator properties.(ABSTRACT TRUNCATED AT 250 WORDS)
D000328:Adult; D000787:Angina Pectoris / Q000188:drug therapy* / Q000209:etiology / Q000503:physiopathology; D002986:Clinical Trials as Topic; D004347:Drug Interactions; D004359:Drug Therapy, Combination; D006352:Heart Ventricles; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D008297:Male; D008790:Metoprolol / Q000008:administration & dosage* / Q000009:adverse effects; D008875:Middle Aged; D005082:Physical Exertion; D014700:Verapamil / Q000008:administration & dosage* / Q000009:adverse effects
D014700:Verapamil; D008790:Metoprolol