T wave changes after acute myocardial infarction predicting reinfarction.

Of 420 consecutive patients with acute myocardial infarction who survived the coronary care unit period, 57 developed 63 reinfarctions with 16 deaths within three months (reinfarction group). Of the remaining 363 patients, 28 died without evidence of reinfarction during the same observation period and 335 survived. The last ECGs before discharge, or prior to a reinfarction in hospital, of the reinfarction patients were studied and compared with time-matched ECGs from the 335 survivors without reinfarction. In ECGs without interfering patterns, the slope of the ascending limb of a negative T wave was measured as the angle to the vertical plane (interobserver variation less than or equal to 5 degrees in 95%). Of the 63 reinfarctions, 40% had a steeply ascending limb of a negative T wave (T wave angle less than or equal to 55 degrees in lead II, less than or equal to 35 degrees in CR4 and/or less than or equal to 40 degrees in CR7) and a QRS complex without signs of infarction in the same lead (abnormal Q waves or abnormal R wave progression). The same criteria were fulfilled by 6% of the 335 survivors without reinfarction (p less than 0.001) and by one of the 28 patients who died without reinfarction. Thus, a steeply ascending limb of a negative T wave in the acute phase of a myocardial infarction heralds a reinfarction if the QRS complex of the same lead does not show signs of infarction (3-month sensitivity 40% and predictive value 53%). A T wave angle less than or equal to 35 degrees in CR4 corresponds to less than or equal to 40 degrees in V4. CR7 is not transferable to V6 but was the least predictive lead.