ACUTE MYOCARDIAL-INFARCTION - THE ANGIOGRAPHIC PICTURE - NEW INSIGHTSINTO THE PATHOGENESIS OF MYOCARDIAL-INFARCTION

The angiographic appearance of the coronary arteries were examined in 302 patients with stable angina pectoris and compared to 308 patients with acute myocardial infarction, who received high-dose intravenous t hrombolytic therapy, in order to elucidate the underlying angiopatholo gical picture in the two diseases. In each group coronary lesions were present in proximal segments of the arteries and were closely related to bifurcations. Lesions were more extensively distributed in the cor onary tree in patients with stable angina and they had an average of 5 .4 lesions per patient, compared to the acute myocardial infarction gr oup who had only 2.4 lesions. Also, in the acute myocardial infarction patients, four-fifths of the culprit arteries were patent, 104 (34%) had a ruptured plaque, 22 (7%) had an ulcerated plaque and in 190 (62% ) the lesions were eccentric. The study shows that patients with myoca rdial infarction who are suitable for thrombolysis have a unique coron ary angiographic picture and the acute episode is caused by sudden rup ture of a localized atheromatous plaque which initiates an obstructive thrombotic cascade.