Ventricular repolarization evaluation from surface ECG for identification of the patients with increased myocardial electrical instability

In order to reveal the possible correlation between the level of myocardial electrical instability assessed at Holter monitoring and certain ECG parameters characterizing ventricular repolarization 24-hours ECG recordings were analyzed in 91 patients with different grades of ventricular arrhythmias. The following parameters were calculated: RT-interval (RT) duration and variability, RT apex interval (RTa) duration and variability, areas of the first and second half of T-wave (S1, S2) and maximal rise and fall slopes of T-wave (k1, k2). An original signal processing algorithm for ECG was developed for that purpose. The results of the study suggest that complex analysis of certain T-wave parameters, as well as RT interval variability can be a useful tool for identification of patients at increased risk of sudden death.