[Effect of intracoronary and intravenous administration of propranolol on coronary vasomotility at rest and during exercise].
The effect of intracoronary and intravenous propranolol on coronary vasomotion was evaluated in 30 patients with coronary artery disease. Luminal area of a normal and a stenotic coronary segment was determined at rest, during supine bicycle exercise and 5 min after 1.6 mg sublingual nitroglycerin administered at the end of the exercise test using biplane quantitative coronary arteriography. Patients were divided into 3 groups: Group I (n = 12) served as control Group II consisted of 10 patients with intracoronary administration of 1 mg propranolol and Group III of 8 patients with intravenous administration of 0.1 mg/kg propranolol prior to the exercise test. 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 both normal (+40%, p less than 0.001 vs rest) and stenotic (+12%, NS vs rest) segments. In Group II intracoronary propranolol was not accompanied by a change in coronary area but both normal (+13%, p less than 0.05) and stenotic (+22%, p less than 0.05) 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 III intravenous administration of propranolol was associated with a decrease in coronary luminal area of both normal (-24%, p less than 0.001) and stenotic (-41%, p less than 0.001) segments. During dynamic exercise there was coronary vasodilation of both segments when compared to the data after intravenous injection of propranolol but there was no change in luminal area (normal vessel-2%, NS vs rest; stenotic vessel-3%, NS vs rest) when compared to the resting data. After sublingual administration of 1.6 mg nitroglycerin both normal (+21%, p less than 0.001) and stenotic (+46%, p less than 0.001) segments showed coronary vasodilation. It is concluded that supine bicycle exercise in patients with coronary artery disease is associated with vasodilation of the normal and vasoconstriction of the stenotic coronary arteries. Intravenous administration of propranolol is followed by coronary vasoconstriction of both normal and stenotic coronary arteries probably due to secondary mechanisms (reduction in heart rate and contractility) because it is not observed after intracoronary injection of propranolol and it is overridden by bicycle exercise and sublingual nitroglycerin.
Bortone
A
A
Hess
O M
OM
Gaglione
A
A
Locuratolo
N
N
Troito
G
G
Rizzon
P
P
Chiddo
A
A
D000328:Adult; D000368:Aged; D000787:Angina Pectoris / Q000503:physiopathology*; D017023:Coronary Angiography; D003324:Coronary Artery Disease / Q000503:physiopathology*; D003331:Coronary Vessels / Q000187:drug effects* / Q000503:physiopathology; D005080:Exercise Test; D006334:Heart Function Tests; D006801:Humans; D007275:Injections, Intravenous; D008875:Middle Aged; D011187:Posture; D011433:Propranolol / Q000008:administration & dosage / Q000494:pharmacology*; D014661:Vasoconstriction / Q000187:drug effects; D014664:Vasodilation / Q000187:drug effects
D011433:Propranolol
Effetto della somministrazione endocoronarica ed endovenosa di propranololo sulla vasomotilità coronarica a riposo e durante esercizio.