Dynamic response of temporal and spatial ventricular repolarization dispersion indices during abrupt heart rate changes.

MARCOS TEPERINO; PABLO CRUCES; ANA MINCHOLÉ; PABLO LAGUNA; MARIA PAULA BONOMINI

Bariloche

Conferencia; RPIC 2013; 2013

Ventricular repolarization dispersion (VRD) has been shown to constitute a substrate for arrhythmias. We analyzed the evolution of different electrocardiogram indices of VRD responding to changes in heart rate (HR) induced by a Tilt-test in healthy subjects. We studied temporal indices of VRD (T-VRD), based on ECG-intervals, and spatial indices of VRD (S-VRD), based on spatial correlation matrix eigenvalues of the electrocardiogram. In T-VRD analysis, the T-wave onset-to-peak ITOP index showed significant decrease during abrupt RR decreases with respect to supine position. Regarding S-VRD, we observed a significant increase of the first eigenvalue of the ascending T-wave limb I1A for abrupt RR decreases with respect to supine position. Conversely, we found non-significant changes in the T-wave peakto- end ITPE and in the first eigenvalue of the descending T-wave limb I1D. Results indicate that under HR increases the first portion of T-wave, ITOP and I1A, has changed significantly with respect to supine position. Moreover, considering that VRD between two site either at epicardium and endocardium, or other apicobasal sites defines the peak of the T-wave, we can concluded that the global action potential duration distance responsible for ITOP respond to abrupt increases of HR, whereas ITPE and I1D, are not significantly altered.