KEY WORDS: Coronary vasomotion, quantitative coronary arteriography, bicycle exercise, intracoronary and intravenous propranolol, coronary artery disease, nitroglycerin. In NS vs rest; NS vs rest)
The effect of intracoronary and intravenous propranolol on coronary vasomotion was evaluated in
the control group there was coronary vasodilation (+23%, P <001) of the normal and coronary vasoconstriction (-29%, P < 0-001) of the stenotic vessel segment during bicycle exercise. After sublingual administration of 1-6 mg nitroglycerin there was vasodilation of-both normal (+40%, P <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<0-05) and stenotic (+22%, P<0-05) vessel segments showed coronary vasodilation during bicycle exercise. After sublingual nitroglycerin there was further vasodilation of both normal (+31 %, P < 0-001 vs rest) and stenotic (+45%, P < 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 <0-001) and stenotic (-31%, P <0-001) vessel segments. During dynamic exercise there was coronary vasodilation of both vessel segments when compared with the data after intravenous injection of propranolol but there was no change in luminal area
Introductionand exercise-induced myocardial ischaemia. The _, .. .