Improvement in left ventricular intrinsic dyssynchrony with cardiac resynchronization therapySerdar Bozyel1, Ayşen Ağaçdiken Ağır2, Tayfun Şahin2, Umut Çelikyurt2, Müjdat Aktaş2, Onur Argan3, İrem Yılmaz4, Kurtuluş Karaüzüm1, Emir Derviş2, Ahmet Vural2, Dilek Ural5
1Department of Cardiology, Derince Training and Research Hospital; Kocaeli-Turkey
2Department of Cardiology, Faculty of Medicine, Kocaeli University; Kocaeli-Turkey
3Department of Cardiology, Kocaeli State Hospital; Kocaeli-Turkey
4Department of Cardiology, Seka State Hospital; Kocaeli-Turkey
5Department of Cardiology, Faculty of Medicine, Koç University; İstanbul-Turkey
Objective: Cardiac resynchronization therapy (CRT) has been shown to induce a structural and electrical remodeling; the data on whether left ventricle (LV) reverse remodeling is associated with restitution of intrinsic contraction pattern are unknown. In this study, we investigated the presence of improvement in left ventricular intrinsic dyssynchrony in patients with CRT.Keywords: CRT, intrensek dissenkroni, native QRS duration, reverse remodeling
Methods: A total of 45 CRT recipients were prospectively studied. Dyssynchrony indexes including interventricular mechanical delay (IVMD) and tissue Doppler velocity opposing-wall delay (OWD) as well as QRS duration on 12-lead surface electrocardiogram were recorded before CRT device implantation. After 1 year, patients with chronic biventricular pacing were reprogramed to VVI 40 to allow the resumption of native conduction and contraction pattern. After 46 h of intrinsic rhythm, QRS duration and all echocardiographic measurements were recorded. Dyssynchrony was defined as IVMD >40 ms and OWD >65 ms. CRT response was defined by a ≥15% reduction in left ventricular end-systolic volume (LVESV) at a 12-month follow-up.
Results: Thirty-two patients (71%) showed response to CRT. The native QRS duration reduced significantly from 150±12 ms to 138±14 ms (p<0.001), and dyssynchrony indexes showed a significant improvement only in responders. The mean OWD reduced from 86±37 ms to 50±29 ms (p<0.001), and the mean IVMD decreased from 55±22 ms to 28±22 ms (p<0.001) in responders. The reduction in LVESV was significantly correlated with ΔOWD (r=0.47, p=0.001), ΔIVMD (r=0.45, p=0.001), and ΔQRS (r=0.34, p=0.022).
Conclusion: Chronic CRT significantly improves LV native contraction pattern and causes reverse remodeling in dyssynchrony. (Anatol J Cardiol 2017; 17: 000-00)
Corresponding Author: Serdar Bozyel, Türkiye