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.