Acute anterior wall myocardial infarction entailing ST-segment elevation in lead V1: electrocardiographic and angiographic correlations.

Abstract

The correlation between ST elevation in lead V1 during anterior wall acute myocardial infarction (AMI) and the culprit lesion site in the left anterior descending (LAD) coronary artery is poor. The study was undertaken to assess the electrocardiographic (ECG) characteristics and angiographic significance of ST-segment elevation in lead V1 during anterior wall acute myocardial infarction (AMI). Data from 115 patients with anterior wall AMI, who underwent coronary angiography within 14 days of hospitalization, were studied. The admission 12-lead ECG was examined and the coronary angiogram was evaluated for the nature of the conal branch of the right coronary artery (RCA) and for the culprit lesion site in the left anterior descending (LAD) coronary artery. Mean ST-segment deviation and the frequency of patients with ST-segment elevation > 0.1 mV were significantly lower in lead V1 than in lead V2 (0.136 +/- 0.111 mV vs. 0.421 +/- 0.260 mV, and 37 vs. 96%, for leads V1 and V2, respectively). A small conal branch not reaching the interventricular septum (IVS) was more prevalent among patients with ST-segment elevation > 0.1 mV in lead V1 (67%), whereas a large conal branch was more prevalent in patients with ST-segment deviation (1 mV in that lead (83%, p < 0.001). No relation was found between ST-segment deviation in lead V1 during anterior wall AMI and the culprit lesion site in the LAD. ST-segment elevation in lead V1 during first anterior wall AMI was found in one third of the patients, and its magnitude was lower than that in the other precordial leads. ST-segment elevation in lead V1 favors the presence of a small conal branch of the RCA that does not reach the IVS.