Normal Ventricular Repolarization Dispersion Range with Abrupt Heart Rate Changes

PABLO CRUCES; MARIA P BONOMINI; MARCOS TEPERINO; ANA MINCHOLÉ; PABLO LAGUNA; PEDRO D ARINI

Boston

Congreso; Computing in cardiology (CINC); 2014

Ventricular repolarization dispersion (VRD) constitutes a substrate for arrhythmias. We characterized the range of normal variations of different electrocardiographic indices of VRD responding to changes in heart rate (HR) induced by a tilt-test in healthy subjects as a criterion for lower bound risk stratification. The study group consisted of 17 healthy subjects (28.5±2.8 yrs), who underwent a head-up tilt-test trial according to the following protocol: 4-min in the supine position and 5-min in the standing position tilted head-up to an angle of 70°. We computed, using a multilead criterion to determine T-wave boundaries in the I, III, V1-V6 leads, the following ECG indices: T-wave onset-to-peak interval (TOP), T-wave peakto-end interval (TPE), T-wave amplitude (TA), the ratio of the second to the first eigenvalues of the ascending (λ21A) and descending (λ21D) limb of the T-wave. The statistical analysis was realized by comparing the ECG indices in Supine position (Sp) versus Tilt position (Tp) using a two-sided Mann-Whitney U-test, being (*)p