Summary:In 587 patients with acute myocardial infarction (AMI) and no previous MI, electrocardiographically estimated infarct size was related to 1-and 2-year mortality. The overall mortality was higher in patients with transmural MI (Q-or R-wave changes in standard ECG) than in patients with subendocardial infarction (ST-Twave changes in standard ECG) after 1 year (18.8% compared to 6.5% p0.2). In a subgroup of patients with anterior MI, precordial mapping with 24 chest leads was analyzed 4 days after arrival in hospital (n=197). Patients were divided into quartiles according to the sum of R waves, the sum of Q waves, and the number of Q waves. There was a similar overall mortality in each quartile after 1 year and after 2 years regardless of ECG parameters studied. Neither did we find any correlation between the sum of R waves in leads 11, 111, and aVF on the fourth day in patients with inferior MI and overall 1 -or 2-year mortality rate, although there was a trend towards higher mortality with more ECG changes.