Effect of intracoronary and intravenous propranolol on human coronary arteries.

The effect of intracoronary and intravenous propranolol on coronary vasomotion was evaluated in 28 patients with coronary artery disease. Luminal area of a normal and a stenotic coronary vessel segment was determined at rest, during submaximal bicycle exercise and 5 min after 1.6 mg sublingual nitroglycerin administered at the end of the exercise test involving biplane quantitative coronary arteriography. Patients were divided into three groups: group 1 (n = 12) served as the control group, group 2 consisted of 10 patients with intracoronary administration of 1 mg propranolol and group 3 of six patients with intravenous administration of 0.1 mg kg-1 propranolol prior to the exercise text. In the control group there was coronary vasodilation (+23%, P less than 0.01) of the normal and coronary vasoconstriction (-29%, P less than 0.001) of the stenotic vessel segment during bicycle exercise. After sublingual administration of 1.6 mg nitroglycerin there was vasodilation of normal (+40%, P less than 0.001 vs rest) and stenotic (+12%, NS vs rest) vessel segments. In group 2 intracoronary propranolol was not accompanied by a change in coronary vessel area but both normal (+13%, P less than 0.05) and stenotic (+22%, P less than 0.05) vessel segments showed coronary vasodilation during bicycle exercise. After sublingual nitroglycerin there was further vasodilation of both normal (+31%, P less than 0.001 vs rest) and stenotic (+45%, P less than 0.01 vs rest) arteries. In group 3 intravenous administration of propranolol was associated with a decrease in coronary luminal area of both normal (-24%, P less than 0.001) and stenotic (-31%, P less than 0.001) vessel segments.(ABSTRACT TRUNCATED AT 250 WORDS)