ECG-based clinical indexes during exercise test including repolarization, depolarization and HRV

In this work, we compared ECG clinical ischemia indexes from ventricular depolarization, repolarization and heart rate variability (HRV) measurements during exercise tests. ST segment deviations, ST/heart-rate hysteresis, Q-, Rand S-wave amplitudes, QRS duration and HRV indexes were automatically measured. Coronary angiography was used as the gold standard to include patients in the ischemic group. Multivariate discriminant analysis was applied to classify the patients. Results based on classical ST indexes correctly classified 58% of patients. When depolarization, repolarization and HRV indexes were jointly considered, the exactness improved to 91% (sensitivity=94%, specificity=89%). These results are close to those obtained by exercise echocardiography or exercise nuclear imaging.