Precordial ST-segment changes and serum enzyme levels in acute myocardial infarction.

Serial study of 72-lead precordial ST-maps, SGOT, and SLDH was done in 30 cases of acute myocardial infarction. Infarct size was estimated by sum of ST elevation in all leads (sigma ST), number of sites showing ST elevation (NST), peak SGOT, and peak SLDH levels, and correlated with each other and with clinical features and hospital course. sigma ST correlated well with NST (r=0.92), but the correlations of sigma ST with SGOT (r=0.99) and SLDH (r=3.84) were better than those of NST with SGOT (r=0.22) and SLDH (r=0.53). There were close agreements between sigma ST and peak SGOT and peak SLDH except in the cases of non-transmural infarction, in whom smaller sigma ST suggesting small infract occurred with higher enzyme peaks indicating moderate or large infarct. Longer duration of chest pain, larger number of associated conditions (e.g. angina, hypertension, diabetes), complications (e.g. congestive heart failure, shock, arrhythmias) and mortality were associated with larger infarcts.