Coronary Heart Disease EKG Criteria Predict Infarct-related Artery of

Background: We attempted to predict the infarct-related artery (IRA) of inferior wall acute myocardial infarction (AMI) by assessing the relative ST-segment deviation on surface electrocardiogram (EKG). Methods and Results: We evaluated 12-lead and right-sided EKG with ST-segment elevation-type inferior wall AMI from 528 consecutive patients with AMI in Chi-Mei Foundation Hospital between 1999 and 2002. Patients with previous myocardial infarction or bundle branch block were excluded. Forty cases were enrolled in the study and were divided into two groups according to the IRA, either right coronary artery (RCA) or left circumflex artery (LCX). IRA was determined by the angiographic criteria: the artery supplying the area of asynergy with (1) total or subtotal occlusion, or (2) arteriographic features suggestive of thrombus in arteries with more than 50 % luminal stenosis. Ten EKG criteria were used for comparison. There were two useful EKG criteria for predicting the IRA. Isoelectric or elevated ST-segment in lead I could predict LCX as the IRA with 87.5 % specificity and 63 % sensitivity. Greater ST depression in lead aVL than in lead I and greater ST elevation in lead III than in lead II could predict RCA as the IRA with 50 % specificity and 97% sensitivity. Conclusion: Isoelectric or elevated ST-segment in lead I suggesting LCX as the IRA and greater ST depression in lead aVL than in lead I and greater ST elevation in lead III than in lead II suggesting RCA as the IRA are two useful EKG criteria for identification of IRA of inferior wall AMI. Key Words: Electrocardiogram Infarct-related artery Acute myocardial infarction Coronary artery disease Coronary angiograph