Value of ECG in identifying the infarct-related artery in elderly patients with inferior wall acute myocardial infarction

Objective To investigate the value of electrocardiogram (ECG) in identifying the infarct-related artery (IRA) in elderly patients with inferior wall acute myocardial infarction (AMI). Methods ECGs obtained on admission and the IRAs confirmed by coronary angiography were studied retrospectively in 70 elderly patients with first diagnosed inferior wall AMI. Results The IRAs were left anterior descending coronary artery (LAD) in 3(4%) patients, right coronary artery (RCA) in 53(76%) patients and left circumflex (LCx) in 14(20%) patients. ST elevation in lead V1, ST elevation in lead Ⅲ exceeding that of leadⅡ (ⅢⅡ), ST depression in lead I and(or) lead aVL, and the ratio of ST depression in lead V3 to ST elevation in lead Ⅲ (V3/Ⅲ ratio)≤ 1.2 identified RCA occlusion. Among these criteria, ST elevation in lead V1 had the highest specificity and positive predictive value (PPV) of 100% and 100%,respectively, and ST depression in lead I and(or) lead aVL had the highest sensitivity of 94%. ST depression in lead V1, Ⅲ≤Ⅱ, ST elevation in lead I and(or) lead aVL and V3/Ⅲ ratio1.2 identified LCx as IRA. ST depression in lead V1 had the highest sensitivity and negative predictive value (NPV) of 71% and 89%, respectively, and ST elevation in lead I and(or) lead aVL had the highest specificity and PPV of 100% and 100%, respectively. Conclusions ECG plays an important role in predicting the IRAs in elderly patients with inferior wall AMI.