Dynamics of T-peak-to-T-end Morphology Changes in an Open-chest Porcine Model, and Its Relation to Arrhythmic Events

In this work, we use a time-warping-based morphology variation index, d PCA w,Tpe , computed between the peak and the end of the T-wave, and assess its association with the occurrence of ventricular fibrillation (VF) episodes (VF group) in ECG recordings from 20 pigs undergoing a 40minute coronary occlusion.The d PCA w,Tpe series was obtained by quantifying the morphological differences between the final part of the T wave at different stages of the occlusion and that of a reference T wave from a control recording.During occlusion, the absolute value of d PCA w,Tpe followed a gradual increasing trend as ischemia progressed.At 0-5, 5-10, 10-15 and 15-20 minutes after the occlusion onset, d PCA w,Tpe median values were significantly higher in the VF group than in the non-VF group (10.2, 11.7, 18.2 and 19.0 vs 1.8, 2.4, 3.2 and 2.4 ms), with p-values from the Kruskal-Wallis test of 0.017, 0.041, 0.045 and 0.013, respectively.In contrast, the T PCA pe index did not present significant differences in any of the intervals between VF and non-VF groups.In conclusion, dynamic increases of the d PCA w,Tpe index during ischaemia progression in pigs are associated with VF occurrence.