Use of Dominant T-wave to Reduce T-Wave Offset Location Uncertainty

Abnormalities in the electrocardiographic (ECG) T wave are associated to sudden cardiac death. Despite the QT-interval prolongation being the standard marker of cardiac risk, its reliability is limited by the T-wave offset (Toff) uncertainty provided by different automatic methods. Thus, the aim of the present study was to evaluate if the dominant T wave (DTW) can be used to reduce Toff uncertainty. Our clinical data consisted of a sinus 15-lead ECG beat randomly extracted from ECG recordings of 36 control healthy subjects (CHS) and 62 acute myocardial infarction patients (AMIP). Toff, localized measuring its distance from the preceding R peak, was independently identified in the DTW and in each single-lead T wave by means of the Zhang et al. 's method (M1) and the Daskalov et al.'s method (M2). In both populations the distributions of the temporal distances between Toff values provided by the two techniques for the DTW showed a significantly lower median value than those measured over the 15 leads (CHS: 5 ms vs. 5-18 ms, respectively; AMIP: 10 ms vs. 10-20 ms, respectively), or a comparable median value but a significantly lower variability (CHS: 5 ms vs. 3-10 ms, respectively; AMIP: 5 ms vs. 5-13 ms, respectively). Thus, the use of the DTW allowed a significant reduction of Toff uncertainty.