Usefulness of Precordial T -wave Increase During Exercise Stress Test in Detecting Coronary Artery Disease

The usefulness of T -wave changes observed in precordial derivations (Vı.6) during exercise stress testing (EST), in detecting coronary artery disease (CAD) was evaluated in this study. For this purpose, 163 patients w ere enrolled. Precordial T -wave amplitudes were recorded before exercise, immediately after peak exercise and at Iate recovery period. Coronary angiographic exaınination was performed later on. Normal coronary arteries in 55 patients (Group-1) , single-vessel disease in 73 patients (Group-2) and ınulti-vesse l d isease in 35 patients (Group-3) were found. In evaluation of precordial T-wave amplitudes at base and in maximal heart rate during EST, significant T-wave amplitude increase was found in leads V3.6 in patients with normal coronary arteries (Group- i ), and in Ieads Vı.6 in patients with CAD (group 2-3). In all precordial leads. Vı had the highest sensitivity and specificity (21% and 87%, respectively) in detecting coronary artery disease when 3 ının or more increase in T-wave amplitude was accepted as a positive c riterion for CAD (cut-off value=3). An increase of C.3 mm in T-wave aınplitude was observed ıno stly in proximal LAD disease among all patients (13/33, 39%) and when only T -wave criterion was evaluated, overall specificity was increased slightly (from 78% to 87%, p>0.05). When T-wave aınplitude increase and ST segment depression were evaluated individually, significant increase in sensitivity was detected only in the single-vessel group (from 56% to 7 1%, p<0.002) and a slight increase in diagnostic accuracy was observed in all patients and in single-vessel disease (from 70% to 74% and from 66% to 70%, respectively, p>0.05). Combining these two criteria, the overall sensitivity decreased to ıo%, however specificity increased from 78% to 96% (p<0.005). In conclusion, an increase of 3 mm or more in Twave amplitude in lead Yı during EST is evident especially in severe proximal LAD stenosis among all patients, and evaluation of this criterion on ST segment depression individually, may be useful especially in increasing sensitivity in one-vessel disease, combining these criteria with ST segment depression may be useful in diminishing falsepositive results in EST.