Relation of lateral ST-segment elevation pattern to myocardial salvage in patients with recanalized anterolateral acute myocardial infarction.

Abstract

Although anterior acute myocardial infarction (AMI) with ST-segment elevation in lateral leads is associated with a poor prognosis, the significance of the pattern of lateral ST-segment elevation has not been examined. The aim of the study was to examine the relation of the pattern of lateral ST-segment elevation to myocardial reperfusion and infarct size in patients with AMI. We studied 111 patients who had a first AMI presenting with anterolateral ST-segment elevation and Thrombolysis in Myocardial Infarction (TIMI) grade 3 flow of the left anterior descending coronary artery within 6 h from symptom onset. Patients were classified into two groups according to the pattern of lateral ST-segment elevation on the admission electrocardiogram: Group 1, 42 patients with equivalent or greater ST-segment elevation in lead I than in lead aVL, and Group 2, 69 patients with lesser ST-segment elevation in lead I in than in lead aVL. Left ventricular ejection fraction (LVEF) was measured by predischarge left ventriculography. There were no differences between the two groups in age, gender, time from onset to recanalization, culprit lesion, or collateral development. Group 1 patients had a higher probability of impaired myocardial reperfusion as indicated by a myocardial blush grade of 0 or 1 after recanalization, a higher peak creatine kinase level, and a lower LVEF than Group 2 patients (p = 0.0001, respectively). We conclude that equivalent or greater ST-segment elevation in lead I than in lead aVL is associated with impaired myocardial reperfusion and less myocardial salvage in patients with recanalized AMI who present with anterolateral ST-segment elevation on the admission electrocardiogram.