Estimation of final infarct size and severity of left ventricular dysfunction by the predischarge electrocardiographic pattern in patients with first anterior wall acute myocardial infarction

This study was undertaken to evaluate the value of the predischarge electrocardiogram in predicting find infarct size and severity of left ventricular dysfunction in patients with a first anterior wall acute myocardial infarction. Fifty seven patients with a first anterior wall acute myocardial infarction underwent 12 lead electrocardiogram and ^99mTc- sestamibi scan for myocardial perfusion defect size (% of myocardium) and left ventricular ejection fraction before discharge from the coronary care unit (day 4-10 after admission). Patients were divided into three groups: A=no ST elevation; B=ST elevation (≥ 0.1 mV) and negative T waves in ≥2 consecutive precordial leads; and C=ST elevation (≥ 0.1 mV) and positive upright T waves in ≥2 consecutive precordial leads. Groups A, B, and C included 13, 27, and 17 patients, respectively. Left ventricular ejection fraction was higher in Group A than in Groups B and C (44±14% 40±9%, and 31±9%, respectively, p=0.002). Myocardial perfusion defect size (% myocardium) was significantly higher in Group C compared to Groups B and A (48±16%, 39±17%, and 32±16%, respectively, p=0.036). Patients with ST elevation and positive T waves in the precordial leads in the predischarge electrocardiogram had larger myocardial infarct size and more severe left ventricular dysfunction than patients with complete resolution of ST segment elevation or patients with ST elevation and negative T waves. (C) 2000 by Le Jacq Communications, Inc.