Abstract
The electrocardiograms of patients in whom myocardial infarction was excluded at autopsy are presented to bring out (1) differentiation of patterns due to subendocardial ischemia or hypopotassemia from those due to subendocardial infarction; (2) differentiation of cove-plane T inversion associated with subepicardial myocarditis or ischemia from that accompanying myocardial infraction; (3) errors resulting from attempts to draw diagnostic inferences from the registraition of prominent Q waves and/or cove negative T waves in ectopic beats or tachycardias.