Total occlusion of the left main coronary artery: report of seven cases from 5312 cardiac catheterizations and review of the literature.

Of the 5312 cardiac catheterizations performed at the Clayton Foundation for Research Cardiovascular Laboratories from 1974 to early 1981, seven patients (0.13%) had total occlusion of the left main coronary artery. All seven had a history of myocardial infarction, and were markedly symptomatic (New York Heart Association, Classes III and IV), with anginal pain that had existed from 2 to 13 years. Left ventricular end-diastolic pressure was notably elevated in all patients, and ejection fractions ranged from 16% to 69%. In all patients, there was significant collateral circulatory flow to the left coronary system from the right coronary artery and its branches. Six underwent coronary artery bypass at our institution, and one was operated on at another hospital. The six patients operated on in our institution were markedly improved after the operation. Our results support previously reported findings about patients with total occlusion of the left main coronary artery in that (1) no definitive clinical pattern leads to simple diagnosis, (2) the anomaly is rarely encountered during cardiac catheterization, and (3) myocardial revascularization alleviates symptoms and prolongs life.