Observations on the diagnostic criteria of the "nontransmural" acute myocardial infarction.

In 15 patients with acute myocardial infarction (AMI) lacking Q waves ("nontransmural"), selected from 317 patients with AMI, successively observed, diagnostic criteria and evolution were analysed. Clinical and enzymatic diagnostic criteria of the "nontransmural" AMI indicated a significant myocardial necrosis. Anginal pain was particularly recurrent. Various and variable electrocardiographic signs (ST--T changes, arrhythmias, etc.) suggested a significant, extensive, myocardial damage. Complications (heart pump failure, arrhythmias, peripheral and cerebral ischemic attacks), frequently severe, occurred in the majority of the patients. "Nontransmural" AMI occurred mainly in patients older than 60, with systemic arterial involvement. Four of the patients died (two during the acute phase); in one of them, transmural AMI, suggested by a complicating pericarditis, was confirmed by necropsy. The so-called "nontransmural" AMI proved to be an actual or potentially severe condition. Its differentiation from the "transmural" AMI on the basis of electrocardiographic criteria is artificial and unjustified.