ST-segment depression in aVR as a predictor of culprit artery in acute inferior wall ST-segment elevation myocardial infarction

To investigate whether the ST changes in the aVR lead on 12-lead ECG can be used to identify infarct-related artery (IRA) in patients with acute inferior ST-segment elevation myocardial infarction. The ECG features were studied in 56 patients with acute inferior myocardial infarction where IRA was confirmed by coronary angiography. Right coronary artery (RCA) and the left circumflex coronary artery (LCX) were identified as IRA in 41 and 15 patients, respectively. ST depression in aVR ⩾0.1 mV was found in 9 (60%) patients who had LCX as the IRA, and in 5 (12.2%) (2p < 0.001) patients with RCA as IRA. Using ST segment depression ⩾0.1 mV in aVR as a criterion, the sensitivity and specificity in differentiating LCX as IRA was 60% and 87.80%, respectively. ST depression in aVR is common in patients with LCX-related acute inferior myocardial infarction. The ST changes in this lead are associated with an excellent specificity and a good sensitivity in differentiating LCX from RCA as the IRA.