Evaluation of Different ECG Parameters to Predict the Culprit Artery and Site of Occlusion in Patient with Acute Inferior Wall Myocardial Infarction

Abstract

The determination of infarct related artery in acute inferior myocardial infarction (MI) is extremely important. The present study aimed to evaluate the use of different ECG criteria to predict the culprit artery and site of occlusion in patients with acute inferior wall MI. The study conducted 100 patients (51.3±10.2 yrs, 79% males) presented by acute inferior MI. All patients were subjected to surface 12-lead ECG. Four ECG criteria were analyzed for prediction of culprit artery; ST segment depression in lead aVR >1 mV, ST segment elevation in lead III more than lead II, ST segment depression in lead I >0.05 mV and ST segment elevation in lead V4R > 1mV. The sum of ST segment elevation in lead II, III and aVF and ST segment elevation in lead V4R > 1mV were analyzed to predict the site of occlusion. Patients were divided into 2 groups based on the angiographic definition of the culprit artery: Group I included 79 patients (79%) with RCA lesion and Group II included 20 patients (20%) with LCX lesion. Only 1 patient (1%) was excluded because he had normal coronary angiography. In Group I, the ST segment elevation in lead III greater than lead II and ST segment depression in lead I > 0.05 mm had a comparable sensitivity (78% and 71% respectively) and specificity (60%. and 65% respectively) for RCA as the culprit artery. The ST segment elevation ≥ 1mm in V4R had very low sensitivity (37%) and highest specificity (100%). In Group II, ST segment depression ≥ 1mm in aVR was the best criteria for LCX as the culprit artery with sensitivity of 60% and specificity 81%. The sum of ST segment elevation in lead II, III and aVF was higher in proximal RCA (8.51±4.44mm) than both mid RCA (5.95 ± 3.06 mm) and distal RCA (5.00 ± 2.77 mm) (P value <0.001). The study concluded that it is possible to predict the culprit coronary artery in acute inferior wall MI by using the readily obtainable measures on the admission ECG.