Effects of aging on the autonomic modulation of the ventricular repolarization dispersion

PABLO CRUCES; MARIA PAULA BONOMINI; MARCOS TEPERINO; PEDRO ARINI

Congreso; XX Congreso Argentino de Bioingenieria; 2015

The study of ventricular repolarization dispersion (VRD) is of relevant concern in cardiac pathophysiology. However, the high number of physiological variables involved makes the origin of the VRD remains incompletely understood. We have analyze how aging influences theautonomic modulation of VRD in response to postural changes. Through a Tilt-Test we have induced abrupt postural changes to young and middle-aged healthy subjects and have studied the evolution of several dispersion markers: Duration ones, based on electrocardiogram intervals;energy ones, developed through a Principal Components Analysis (PCA) in T-wave; and the morphology one, extracted feature from an absolute T-wave. In both groups, results have shown significant decreases in early repolarization. Moreover, we have found significant decreases in total, early and late repolarization energy, and in the T-wave amplitude. In another sense, we have observed that the repolarization energy obtained by PCA jointly with early T-wave slope and amplitude have been able to reflects VRD differences between young and middle-aged subjects. Finally, this work provides the range of values for VRD in normal conditions which may contribute to the design of an optimal cardiac risk marker.