Determinants of ST-segment level in lead aVR in anterior wall acute myocardial infarction with ST-segment elevation.

BACKGROUND: This study aimed to clarify the determinants of ST-segment level in lead aVR in anterior wall acute myocardial infarction (AAMI).

METHODS: We analyzed ST-segment levels in all 12 leads on admission and emergency coronary angiographic findings in 261 patients with a first AAMI with ST-segment elevation. The length of the left anterior descending coronary artery (LAD) was classified as follows: short = not reaching the apex; medium = perfusing less than 25% of the inferior wall; long = perfusing 25% or more of the inferior wall.

RESULTS: The ST-segment level in lead aVR correlated significantly with the ST-segment levels in leads I, II, III, aVF, V(1), and V(3-6), especially with those in leads II and V(6) (r = -0.63, P < .001; r = -0.61, P < .001; respectively). Patients with a proximal LAD occlusion had a greater ST-segment level in lead aVR than those with a distal LAD occlusion (P < .001). Patients with a long LAD had a lower ST-segment level than those with a short or medium LAD (P < .05).

CONCLUSIONS: The ST-segment levels, especially in leads II and V(6), the site of the LAD occlusion, and the length of the LAD affect the ST-segment level in lead aVR in ST-segment elevation AAMI.