ACUTE MYOCARDIAL-INFARCTION ENTAILING ST-SEGMENT ELEVATION IN LEAD AVL - ELECTROCARDIOGRAPHIC DIFFERENTIATION AMONG OCCLUSION OF THE LEFT ANTERIOR DESCENDING, FIRST DIAGONAL, AND FIRST OBTUSE MARGINAL CORONARY-ARTERIES

Acute myocardial infarction with ST elevation in lead aVL may represen t involvement of the first diagonal or the first obtuse marginal branc h. This study assesses the correlation among different electrocardiogr aphic patterns of acute myocardial infarction with ST elevation in aVL and the site of the infarct-related artery occlusion. Patients who un derwent coronary angiography within 14 days of infarction with an uneq uivocal culprit lesion were included. Fifty-seven patients were evalua ted. The culprit lesion was in the left anterior descending coronary a rtery proximal to the first diagonal, first diagonal, and first obtuse marginal branches, in 38, 8, and 11 patients, respectively. ST elevat ion in aVL and V-2 through V-5 signifies left anterior descending arte ry occlusion proximal to the first diagonal branch (positive predictiv e value [PPV] and negative predictive value [NPV] of 95% and 94%, resp ectively). ST elevation in aVL and V-2, not accompanied by ST elevatio n in V-3 through V-5, favors occlusion of the first diagonal branch (P PV, 89%; NPV, 100%). ST elevation in aVL accompanied by ST depression in V-2 predicts obstruction of the first obtuse marginal branch (PPV, 100%; NPV, 98%).