[Usefulness of the electrocardiogram in predicting the occlusion site in acute anterior myocardial infarction with isolated disease of the left anterior descending coronary artery].

INTRODUCTION AND OBJECTIVES In acute anterior myocardial infarction (AMI), the site of occlusion in the left anterior descending coronary artery (LAD) is related to the extension of myocardial necrosis and the prognosis. The aim of this study was to assess the value of the electrocardiogram (ECG) as a predictor of the LAD occlusion site in patients with anterior AMI. METHODS Forty-five consecutive patients with a first anterior AMI and isolated disease of the LAD were included. We evaluated retrospectively the ECG with the most pronounced ST-segment changes before fibrinolysis and correlated the findings with the site of LAD occlusion in angiography before hospital discharge in relation to the first dominant septal and first diagonal branch: first septal affected (S), first diagonal affected (D), both affected (S + D), or neither affected were considered. RESULTS ST depression in leads II, III, or aVF strongly predicted proximal LAD occlusion in S + D, S, and D (p = 0,003, p = 0,04, and p = 0,02, respectively). ST elevation in leads II, III, or aVF was observed only in the presence of wrap-around LAD and was related with occlusion distal to the first diagonal branch. ST elevation > or = 3 mm in lead V1 was a specific predictor of occlusion proximal to first septal (S, p = 0,01). ST elevation in aVR was associated with proximal LAD occlusion in S + D and S (p = 0,03 and p = 0,03, respectively) and absence of coronary collateral circulation. CONCLUSIONS In anterior AMI and isolated LAD disease, the ECG can be useful in predicting the LAD occlusion site in relation to its major side branches.