Improved criteria for localization of coronary artery disease from the exercise electrocardiogram.

To derive better criteria for the noninvasive localization of coronary artery disease, a 12-lead computer-averaged rest and exercise electrocardiogram was examined in 44 selected patients (34 men, 10 women) with single-vessel disease who had an exercise test positive for ischemia by established criteria. Left anterior descending disease was characterized by S-T segment elevation (> or = 0.05 mV) in lead V1 [sensitivity (S) 71%, specificity (Sp) 100%], a T wave amplitude increase in V1 (S 88%, Sp 73%) and a leftward shift or no change in mean frontal plane QRS axis (AQRS; S 92%, Sp 93%). Patients with circumflex or right coronary artery disease had no S-T segment elevation in V1 and a rightward shift in the mean frontal plane AQRS.