The development of "pathologic" Q waves with ST segment elevation is considered diagnostic of transmural myocardial infarction. Previous reports have suggested that myocardial ischemia without infarction can result in electrocardiographic abnormalities simulating those of acute infarction. However, lack of infarction has been poorly documented in these reports. If real, this phenomenon could have an impact on the management of patients with apparent acute infarction. This study describes a patient with documented severe myocardial ischemia and electrocardiographic evidence of acute transmural myocardial infarction, in whom significant myocardial necrosis has been excluded definitively.