Prediction of acute left main coronary artery obstruction by 12-lead electrocardiography - ST segment elevation in lead aVR with less ST segment elevation in lead V-1

Objectives We sought to determine the electrocardiographic (ECG) features a ssociated with acute left main coronary artery (LMCA) obstruction. Background Prediction of LMCA obstruction is important with regard to selec ting the appropriate treatment strategy, because acute LMCA obstruction usu ally causes severe hemodynamic deterioration, resulting in a less favorable prognosis. Methods We studied the admission 12-lead ECGs in 16 consecutive patients wi th acute LMCA obstruction (LMCA group), 46 patients with acute left anterio r descending coronary artery (LAD) obstruction (LAD group) and 24 patients with acute right coronary artery (RCA) obstruction (RCA group). Results Lead aVR ST segment elevation (>0.05 mV) occurred with a significan tly higher incidence in the LMCA group (88% [14/16]) than in the LAD (43% [ 20/46]) or RCA (8% [2/24]) groups. Lead aVR ST segment elevation was signif icantly higher in the LMCA group (0.16 +/-0.13 mV) than in the LAD group (0 .04 +/-0.10 mV). Lead V-1 ST segment elevation was lower in the LMCA group (0.00 +/-0.21 mV) than in the LAD group (0.14 +/-0.11 mV). The finding of l ead aVR ST segment elevation greater than or equal to lead V-1 ST segment e levation distinguished the LMCA group from the LAD group, with 81% sensitiv ity, 80% specificity and 81% accuracy. A ST segment shift in lead aVR and t he inferior leads distinguished the LMCA group from the RCA group. In acute LMCA obstruction, death occurred more frequently in patients with higher S T segment elevation in lead aVR than in those with less severe elevation. Conclusions Lead aVR ST segment elevation with less ST segment elevation in lead V-1 is an important predictor of acute LMCA obstruction. In acute LMC A obstruction, lead aVR ST segment elevation also contributes to predicting a patient's clinical outcome. (J Am Coll Cardiol 2001; 38:1348-54) (C) 200 1 by the American College of Cardiology.