Evaluation of T-wave morphology dispersion in high-resolution ECG for risk stratification of sudden cardiac death

The aim of study was to evaluate the prognostic value of T-wave morphology dispersion (TMD) in high resolution ECG for sudden cardiac death risk assessment. The high-resolution ECG signals were recorded at rest in a electrically shielded room and averaged in time using cross-correlation method. The singular value decomposition was applied to HR ECG signals. Evaluated parameters were defined as the mean angle of all pairs of ECG leads reconstruction base vectors: for whole T wave segment (TMD), T-wave ascending slope (TMDpre), and T-wave descending slope (TMDpost). Sensitivity and specificity of T-wave morphology dispersion descriptors in detection of myocardial infarction patients at risk of ventricular tachycardia (VT) were tested on two groups: 30 pts. with documented VT and 13 pts. without VT. Results of the study show significant differences between VT pts and non VT pts groups for all evaluated parameters. The highest sensitivity and specificity showed TMD parameter which could be sensitive marker of the risk of the sudden cardiac death. The presented results suggest that repolarization dispersion indicators may be used in qualification process to implantable cardioverter-defibrillator therapy.