ST-T integral and T-wave amplitude in detection of exercise-induced myocardial ischemia evaluated with body surface potential mapping.

Abstract Body surface potential mapping is superior to 12-lead electrocardiogram in detection of acute and old myocardial infarctions. We examined the capability of the ST-T integral and T wave to detect exercise-induced ischemia in body surface potential mapping. Body surface potential mapping with 123 channels was recorded in 70 subjects: 45 coronary artery disease (CAD) patients and 25 healthy controls during supine bicycle exercise testing. Of the patients, 18 had anterior, 14 posterior, and 13 inferior ischemia documented by coronary angiography and thallium scintigraphy. The ST-T isointegral area, as well as the positive and negative ST-T area, and the T-wave apex amplitude were determined. Discriminant index analysis was used to find the sites that optimally separated patient subgroups from other patients and controls. In the pooled CAD group, the optimal sites for detecting the decrease in ST-T isointegral, in the positive ST-T area and in the T-wave amplitude were over the left side (ST-T isointegral area: CAD −3.8 ± 14 μVs and controls 24 ± 14 μVs; T-wave amplitude: CAD 3 ± 110 μV and controls 190 ± 90 μV; P