[Clinical and angiographic study and pathogenic mechanism of Prinzmetal's angina. Apropos of 31 cases].

31 patients presenting with Prinzmetal variant angina were divided into three groups according to their angiographic appearances. Group I comprised 9 patients with normal or coronary arteries with lesions less than 50% narrowing. Group II comprised 12 patients with single vessel disease. Group III comprised the other 10 patients with significant lesions on two or all three principal arteries. No clinical or electrocardiographical differences were found between the groups as to age, sex or the clinicapresentation of the chest pain. Most patients with normal or nearly normal coronary arteries had normal electrol cardiogrammes between attacjs (8 out of 9) and electrical changes mainly over the inferior wall (8 out of 9). Exercise electrocardiography reproduced ST elevation in 4 of the 9 patients but, in contrast to the patients in the other two groups, never ST depression. However, these features are not specific for patients in Group I as they were observed in 4 patients in the other two groups. Spontaneous or induced coronary spasm were observed in 27 patients, confirming its role as the mechanism of Prinzmetal angina, whatever the anatomical appearance of the coronary tree.