Predicting Ventricular Arrhythmias in Cardiac Resynchronization Therapy: The Impact of Persistent Electrical Dyssynchrony

Karaca O., GÜNEŞ H. M., Omaygenc M. O., Cakal B., Cakal S. D., Demir G. G., ...More

PACE - Pacing and Clinical Electrophysiology, vol.39, no.9, pp.969-977, 2016 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 39 Issue: 9
  • Publication Date: 2016
  • Doi Number: 10.1111/pace.12908
  • Journal Name: PACE - Pacing and Clinical Electrophysiology
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.969-977
  • Keywords: cardiac resynchronization therapy, QRS duration, ventricular arrhythmia, electrical dyssynchrony, mechanical dyssynchrony
  • Istanbul Medipol University Affiliated: Yes


Background: Although response to cardiac resynchronization therapy (CRT) has been conventionally assessed with left ventricular volume reduction, ventricular arrhythmias (ventricular tachycardia/ventricular fibrillation [VT/VF]) are of critical importance associated with unfavorable outcomes even in the “superresponders” to therapy. We evaluated the predictors of VT/VF and the association of residual dyssynchrony during follow-up. Methods: Ninety-five patients receiving CRT were followed-up for 9 ± 3 months. Post-CRT dyssynchrony was defined as a prolonged QRS duration (QRSd) for persistent electrical dyssynchrony (ED), and a Yu index ≥ 33 ms for persistent mechanical dyssynchrony. The first VT/VF episode, including nonsustained VT detected on device interrogation and/or appropriate antitachycardia pacing or shock for VT/VF, were the end points of the study. Results: Forty-five patients who reached the study end points had significantly lower mean ΔQRS (baseline QRSd – post-CRT QRSd) values than those without VT/VF (–20.8 ± 28.9 ms vs –6.6 ± 30.7 ms, P = 0.022). Both the baseline and post-CRT QRSds, along with the Yu index values, were not different in two groups. Patients with VT/VF were statistically more likely to have persistent ED (38% vs 9%, P = 0.021). Kaplan-Meier curves showed that a negative ΔQRS was associated with a higher incidence of VT/VF during follow-up (P = 0.016). A multivariate Cox model revealed that QRS prolongation was an independent predictor of VT/VF after CRT (P = 0.029). Conclusions: A negative ΔQRS, also called persistent ED, is associated with VT/VF. Narrowest possible QRSd might be a reliable goal of both implantation and optimization of devices to reduce arrhythmic events after CRT.