DIFFUSE DISORDER OF CORONARY-ARTERY VASOMOTILITY IN PATIENTS WITH CORONARY SPASTIC ANGINA - HYPERREACTIVITY TO THE CONSTRICTOR EFFECTS OF ACETYLCHOLINE AND THE DILATOR EFFECTS OF NITROGLYCERIN

Objectives. We examined the vasomotility of the entire epicardial coro nary artery system in patients with and without coronary spastic angin a. Background. The coronary arteries of patients with variant angina a re hyperreactive to diverse constrictor stimuli. It is unclear whether the abnormal responses to constrictive or dilative stimuli, or both, result from a localized or diffuse disorder in the coronary artery tre e. Methods. Coronary artery diameter responses to intracoronary acetyl choline and nitroglycerin were examined at the proximal, middle and di stal segments of three principal coronary arteries in 36 patients with coronary spastic angina without significant stenosis and in 12 young (less than or equal to 30 years old) and 20 older control subjects (> 30 years old) with normal coronary arteriographic findings. In 10 pati ents with significant coronary stenosis, the responses of the presteno tic segments were also examined. Results. In patients with coronary sp astic angina, coronary spasm was induced in 23 left anterior descendin g, 13 left circum hex and 17 right coronary arteries by acetylcholine. Multivessel spasm was observed in 15 patients. Acetylcholine had a di lator effect on most segments in young control subjects and a mild con strictor effect in older control subjects and in patients with signifi cant stenosis. Comparison of the responses to acetylcholine among grou ps demonstrated that the constrictor response of the artery with spasm was enhanced significantly and diffusely. That of the artery without spasm also tended to be enhanced. Coronary artery diameters after nitr oglycerin did not differ in any segment among patients with coronary s pastic angina and both control groups. In patients with coronary spast ic angina, nitroglycerin significantly enhanced dilation in all segmen ts of the artery with spasm compared with that observed in both contro l groups and in most segments of the artery without spasm. Patients wi th significant coronary stenosis had a reduced response compared with that in control subjects. Conclusions. Hyperreactive responses not onl y to the constrictor effects of acetylcholine, but also the dilator ef fects of nitroglycerin were detected diffusely in the epicardial coron ary arteries of patients with coronary spastic angina. This finding in dicates that a diffuse, not localized, disorder in vasomotility is inv olved in the pathogenesis of coronary spastic angina.