A 57-year-old man developed anginalike chest pain for the first time but there was no objective evidence of an infarct (i.e., EKG and serum enzymes were normal). After 12 days the pain increased, but EKG and serum enzymes remained normal ("preinfarct," crescendo, unstable, or accelerated angina). At this time a cardiac catheterization showed 90% occlusion of the left anterior descending (LAD) coronary artery. On the 17th day after the onset of pain, severe pain recurred together with an abnormal EKG and the patient was taken immediately to the laboratory where a total occlusion of the LAD was now found and he was treated with intracoronary streptokinase. The artery remained open for only a short time, and balloon angioplasty was performed. However, the patient died 12 hours after onset of the last episode of severe pain. A very early acute myocardial infarct was diagnosed at autopsy together with severe coronary atherosclerosis especially of the LAD which had disruption of atherosclerotic plaques and microscopic evidence of embolization.