Contribution of the peak exercise QT dispersion to the accuracy of an exercise test during the evaluation of coronary artery disease.

Objective: Regional defects in ventricle repolarization are extremely sensitive to ischaemia which can be measured as QT dispersion (QTd). We investigated the role of QTd calculated at the time of peak exercise during treadmill studies.

Methods And Results: Thirty-three women and eighty men, whose treadmill test results and coronary angiography studies had been examined, were divided into four groups according to the test results: 1) subjects with a negative treadmill test and without significant stenosis results in the angiography, were considered normal (N; n = 35); 2) subjects with both a positive exercise test and a significant presence of stenotic coronary arteries, were considered true positive (TP; n = 52); 3) subjects with a positive exercise test, but without significant stenosis results in the angiography, were considered false positive (FP; n = 14); 4) subjects with a negative treadmill study, despite significantly stenotic arteries, were considered false negative (FN; n = 12).