The Effect of Alprenolol on Hemodynamics in Angina Pectoris

Twelve men between 41 and 67 years of age were admitted for preoperative evaluation of angina pectoris. The diagnosis was confirmed by history, ECG at rest and exercise, and coronary arteriograms. Right heart and transseptal left heart catheterization were performed. Cardiac output and intracardiac pressures were determined at rest and during exercise with a load which caused angina pectoris. A β‐adrenergic blocking agent, alprenolol, was then injected intravenously, whereupon the studies at rest and exercise were repeated. The racemic form was given to 8 cases (0.1 mg/kg) and the levo form to 4 cases (0.05 mg/kg). During the first exercise period a pressure rise in the left atrium was found in all cases but one. Alprenolol caused few changes at rest. During the second exercise, with the same load, there was less increase in heart rate and aortic pressure after alprenolol. Four cases could perform the same work after alprenolol with no or with less pain than before. This group differed from the remaining 8 cases in having a higher left atrial pressure rise during the first work test, which also caused a higher heart rate in relation to oxygen consumption. This could mean that they were more hyperkinetic. The improved subjective exercise tolerance in this group was accompanied by less increase in heart rate and left atrial pressure than in those with the same degree of pain.