Value of ST-segment elevation pattern in predicting infarct size and left ventricular function at discharge in patients with reperfused acute anterior myocardial infarction

Background The implication of the shape of ST elevation in the acute phase of myocardial infarction (MI) remains unclear. Methods and Results We examined the relation between the shape of ST elevat ion and infarct size in 77 patients who had a first acute anterior MI with successful reperfusion within 6 hours from symptom onset. A 12-lead electro cardiogram Wets recorded immediately before reperfusion confirmed by corona ry angiography. The shape of ST elevation ill lead Vg Was classified into 3 types: concave type (n = 24), straight type (n = 41), and convex type (n = 12). For concave type, straight type, and convex type, a median value of p eak creatine kinase was 2287, 4371, and 5322 mU/mL, and left ventricular ej ection fraction measured by left ventriculography at discharge (14 days aft er MI) was 58%, 48%, and 41% (P <.05; concave type versus the other 2 types ), respectively. A multivariate logistic regression model demonstrated that the concave type of ST elevation was a strong predicting factor for preser ved left ventricular function (left ventricular ejection fraction greater t han or equal to 50% at discharge; odds ratio 6.2, 95% confidence interval 1 .6 to 20.8, P=0.19). Conclusions In patients with reperfused acute anterior MI, left ventricular function wets excellent in patients with concave type, intermediate in tho se with straight type, and relatively poor in those with convex type ST ele vation at discharge. This simple classification is useful for predicting le ft ventricular function at discharge.