Effect of propranolol on myocardial perfusion images and exercise ejection fraction in men with coronary artery disease.

Propranolol increases exercise performance in association with a decrease in exercise heart rate and blood pressure. In 30 men with coronary disease and exercise limited by angina, 15 without prior infarction and 15 with infarction, we measured left ventricular ejection fraction (LVEF) (scintillation probe) at rest and during supine bicycle exercise and myocardial blood flow distribution (MBF) (thallium-201 imaging) during treadmill exercise. Exercise was performed as control and after 1 week of treatment with propranolol (40 mg orally four times daily). Propranolol improved exercise LVEF (at the same work load) (men without infarction: control 0.37 + 0.02, average ± SEM; propranolol 0.45 0.01; n = 15, p < 0.01; and with infarction: control 0.30 ± 0.01, propranolol 0.36 ± 0.01; n = 15, p < 0.05). Propranolol also improved MBF during exercise to the same work load in men without infarction (comparison of integrated normalized count-rate differences, 607 normalized counts). In men with infarction, propranolol did not alter MBF (15 normalized counts). Placebo did not alter normalized counts by more than ± 150. Changes in exercise LVEF and MBF were related. MBF improved in 17 men with propranolol treatment and LVEF was increased in 15. Of six men who had no change in MBF, exercise LVEF increased in three and did not change in three. Propranolol was associated with a worsening of MBF in five men and all had no change in exercise LVEF. Results suggest that propranolol favorably alters MBF and LVEF in men with coronary disease, particularly in men without prior myocardial infarction.