Evaluation of acute effect of ventricular tachycardia ablation on QT dispersion, Tp-Te interval and Tp-Te/QT ratio in patients with ischemic dilated cardiomyopathy


Uslu A., Küp A., Demir S., Gülşen K., Kepez A. , Akgün T.

35th Turkish Cardiology Congress with International Participation, Antalya, Turkey, 3 - 06 October 2019, vol.22, pp.43

  • Publication Type: Conference Paper / Full Text
  • Volume: 22
  • City: Antalya
  • Country: Turkey
  • Page Numbers: pp.43

Abstract

Background and Aim: There is limited data in the literature regarding the effect of scar tissue on left ventricular (LV) repolarization process in patients with cardiomyopathy. The aim of present study is to evaluate the acute effect of ventricular tachycardia (VT) ablation on dispersion of LV repolarization which is suggested to play a role in initiating and sustaining arrhythmia. Methods: A total of 27 consecutive patients with ischemic cardiomyopathy who had undergone VT ablation constituted our study population. Endocardial mapping was perfomed to all patients and epicardial mapping was performed when endocardial mapping failed to identify desired ablation sites. Substrate mapping was performed using Ensite Precision 3D mapping system (St Jude Medical, Inc., Minnesota, USA). Normal tissue was defined as tissue with bipolar voltage >1.5 mV, dense scar was defined as bipolar voltage <0.5 mV and scar borderzone was defined as a bipolar voltage 0.5-1.5 mV on voltage mapping. Late systolic potentials and local abnormal ventricular activities (LAVA) during sinus rhythm and mid diastolic potentials during VT were tagged as the potential ablation sites (Figure-1). Entrainment maneuvers were performed to identify isthmus if VT was hemodynamically tolerated. Irrigated tip catheters were used during ablation.Electrocardiographic recordings obtained at the time of hospitalization and after the procedure were retrospectively evaluated for the QTc dispersion, Tp-Te interval and Tp-Te/QT ratio which are suggested to be noninvasive markers of dispersion of ventricular repolarization. Significance of difference between electrocardiographic parameters obtained before and after VT ablation was evaluated. Results: There was 23 males (82.1%) in the study population and mean age of the patients was 35.0±12.7 years. Mean ejection fraction was 34.2±9.9. 19 patients (67.9%) were hypertensive and 12 patients (42.9%) were diabetic. There was no significant difference between pre- and post ablation state regarding QTc dispersion Tp-Te interval and Tp-Te/QT ratio (Table-1)). Conclusions: VT ablation did not alter electrocardiographic parameters that are assumed to represent heterogeneity and transmural dispersion of repolarization in the immediate post procedure state. Results of prospective studies are needed to evaluate the chronic effect of VT ablation on myocardial repolarization abnormalities that has the potential to increase tendency for VT initiation.