Survival from acute occlusion of the left main coronary artery with preexisting collateral vessels--a case report.

A thirty-two-year-old man suffered from evolving acute myocardial infarction caused by total occlusion of the left main coronary artery, which was 95% stenosed before the onset. Nevertheless, he had a good clinical course. The myocardium may have been protected by well-developed preexisting collateral vessels as evidenced by serial coronary angiograms.