Relationship between ventricular arrhythmia and repolarisation parameters in patients with biventricular implantable...

Depolarisation parameters obtained from electrocardiography are the basic parameters in cardiac resynchronisation treatment planning. This study examined the relationship of repolarisation parameters obtained before and after the procedure with ventricular arrhythmias and cardiovascular death in patients who underwent cardiac resynchronisation therapy (CRT)- implantable cardioverter defibrillators (ICD) implantation.

Patients who applied to have CRT-ICD implantation were included in the study. ECG records taken at the time of hospitalisation for CRT-ICD implantation and after CRT-ICD implantation were obtained. The time from the peak of the T wave to the intersection between the tangent at the steepest point of the T wave and the isoelectric line was measured digitally in milliseconds.

A total of 80 patients with CRT-ICD due to heart failure and bundle branch block were included in the study. Etiology was ischemic in 43 patients (54%) and non- ischemic in 37 patients (46%). The mean age of the patients was 64.9 ± 9.9 years and 77% were male (n = 62). Seventy (87%) of the patients with CRT were in sinus rhythm, and the mean left ventricular ejection fraction (LV EF) was 29.2 ± 5.8%. In ICD interrogation, VT was detected in 26 patients (32%) and VF in 2 patients (2%). It was determined that 5 (6%) of ventricular arrhythmias were terminated with anti-tachycardia pacing (ATP), and 6 (7%) with shock. A total of 20 (25%) patients died during the mean follow-up period of 43.1 ± 18.4 (7- 114) months after CRT-ICD implantation. Tp-Te values were compared and it was observed that there was a statistically significant prolongation after CRT in leads V5, V6, D1, D2, D3, aVF, aVR, and aVL compared to before CRT. In univariate logistic regression analysis, independent predictors of mortality were LV EF (OR: 0.898, CI: 0.810- 0.994; p = 0.038) and post-CRTQRS duration (OR: 0.978,CI: 0.957-0.999; p = 0.046), whereas in multivariate analysis LV EF was (OR: 0.902, CI: 0.814- 1.000; p = 0.050).Astatistically significant predictive effect of Tp-Te times in leads V2 and V4, which is one of the electrocardiographic parameters after CRT, on ventricular arrhythmia was determined. Tp-Te time in V2 greater than 98.4 ms predicted VT with 57% sensitivity and 68% specificity (AUC: 0.610, 95% CI 0.463-0.757). A Tp-Te time in V4 greater than 100.2 ms predicted VT with 50% sensitivity and 71% specificity (AUC: 0.631, 95% CI 0.487-0.775).

In this study, Tp-Te times in leads V2 and V4 after CRT were found to have a predictive effect on ventricular arrhythmia. Clinical studies with larger series are needed to evaluate the Tp-Te interval as a potential modifiable risk factor for the evaluation of ventricular arrhythmias in patients with CRT-ICD implantation and to demonstrate its effectiveness.