Impact of left ventricular pacing threshold on ventricular arrhythmia occurrence in cardiac resynchronization therapy

Abstract

Cardiac resynchronization therapy (CRT) has been shown to reduce mortality in selected patients with heart failure (HF) [1], however its impact on ventricular arrhythmias (VAs) remains controversial. Several randomized controlled studies have demonstrated that while CRT significantly reduces mortality and HF progression, patients remain at increased risk of VAs [2,3]. Some data also indicate that left ventricular (LV) lead pacing alone could impose a potential proarrhythmic risk [4,5].Global scar burden and myocardial viability at the LV lead position play an important role in CRT response and VA occurrence [6][7][8][9]. A high LV pacing threshold (PT) at resynchronization device implantation may be a contributing factor to the adverse CRT outcome and could indicate a regional myocardial scar [10]. In addition, our previous study demonstrated that lower regional viability in the vicinity of the LV lead pacing site could be associated with increased risk of malignant tachyarrhythmias [11].In this analysis, we sought to determine the relationship between LVPT and myocardial viability at the LV lead position. We also hypothesized that high LVPT would be associated with potential occurrence of VAs. MethodsThe study complies with the Declaration of Helsinki. The study protocol was approved by The National Medical Ethics Committee and all patients gave a written informed consent before entering the study.

Comparison of the electrophysiological properties of the pulmonary veins between paroxysmal and persistent atrial fibrillation

“…Although no statistical significance was observed, the pacing threshold in the RIPV and LIPV also tended to be higher in the perAF cases. Previous reports about ventricles noted that a higher pacing threshold could have an increased risk of arrhythmia occurrence 14 . Similarly, the increase in the pacing threshold in the PVs due to electrical remodeling would contribute to the arrhythmogenesis in perAF.…”

“…Previous reports about ventricles noted that a higher pacing threshold could have an increased risk of arrhythmia occurrence. 14 Similarly, the increase in the pacing threshold in the PVs due to electrical remodeling would contribute to the arrhythmogenesis in perAF.…”