Isolated abnormalities in high precordial leads, an infrequent sign of myocardial infarction

The electrocardiograms of 286 autopsied patients with Q waves in Leads I or aVL who had high precordial leads taken were reviewed. Twenty patients displayed QRS changes of infarction in the high precordial leads, without demonstrating any diagnostic QRS changes in the standard precordial leads. In only two instances was the electrocardiographic diagnosis supported at autopsy. It is suggested by this study that myocardial infarction is the exceptional cause for the electrocardiographic abnormalities seen only in the high precordial leads.