ST Segment Elevation in Leads V5 and V6 for Predicting Culprit Artery in Acute Inferior Wall Myocardial Infarction

Abstract

ST elevation (ST↑) in the leads V5 and V6 to predict the culprit and furthermore, comparing the degree of ST ↑ in lead V6 with that in lead III. Patients were first divided according to the presence (n-62) and absence (n-98) with ST ↑ of ≥2 mm in leads V5 and V6, the patients were then further subdivided into the 2 groups according to the degree of ST ↑ in lead III and in lead V6 and were compared with coronary angiography. In patients with ST ↑ in leads V5 and V6, the infarct related artery was right coronary artery (RCA) in 66% and left circumflex artery (LCx) in 31%. The RCA was found significantly higher proportion in ST ↑ in leads V5 and V6 with ST ↑ in lead III>V6 (n-37; 82%) (p=0.0001), whereas the LCx disease in ST↑  in leads V5 and V6 with ST ↑ in III≤V6 (n-12; 71%) (p-0.0001). The sensitivity, specificity, positive and negative predictive value in ST ↑ in leads V5 and V6 with ST ↑ in lead III>V6 for RCA, and ST ↑ in lead III≤V6 for LCx to predict culprit artery were 90%, 63%, 84%, 75% and 63%, 90%, 75%, 84% respectively. ST elevation in leads V5 and V6 suggests a greater risk area in patient with acute inferior wall myocardial infarction. It also signifies a larger perfusion territory and demands for more aggressive reperfusion therapy.