Abstract
Left bundle branch pacing (LBBP) is a physiological pacing technique that captures the left bundle branch (LBB) directly, causing the left ventricle (LV) to be excited earlier than the right ventricle (RV), resulting in a “iatrogenic” right bundle branch block (RBBB) pacing pattern. Several studies have recently shown that permanent LBBP can completely or partially narrow the wide QRS duration of the intrinsic RBBB in most patients with bradycardia, although the mechanisms by which this occurs has not been thoroughly investigated. This article presents a review of the LBBP in patients with intrinsic RBBB mentioned in current case reports and clinical studies, discussing the technique, possible mechanisms, future clinical explorations, and the feasibility of eliminating the interventricular dyssynchronization accompanied with LBBP.
Highlights
Right ventricular pacing (RVP) has been the standard treatment for patients with symptomatic bradyarrhythmia caused by sinus node dysfunction or atrioventricular conduction disease
Gao et al [19] compared the ECG characteristics of Left bundle branch pacing (LBBP) to those of intrinsic right bundle branch block (RBBB), and discovered that the majority of the QRS morphology in lead V1 of LBBP showed a Qr pattern, whereas the majority of intrinsic RBBB showed a rsR’ pattern. They described an RBBB patient who completed selective LBBP (SLBBP) with the same terminal R’ wave duration of 76 ms as the intrinsic, but which reduced to 58 ms as output increased, suggesting that nonselective LBBP (NSLBBP) could compensate for right ventricle (RV) delay by capturing a portion of cardiomyocytes, which is consistent with the findings of the other studies [22, 23]
LBBP with bipolar tip pacing configuration (BTP) configuration might narrow the intrinsic RBBB duration [15, 23]. This could be due to anodal capture, in which the anode ring penetrated the right side of the septum in a BTP configuration, allowing LBBP to stimulate the left and right septal myocardium as well as left conduction system simultaneously, partially compensating for the RV excitation delay caused by intrinsic RBBB (Figures 1A,C4)
Summary
Right ventricular pacing (RVP) has been the standard treatment for patients with symptomatic bradyarrhythmia caused by sinus node dysfunction or atrioventricular conduction disease. RVP, has been established to cause electrical and mechanical dyssynchronization, which increases the risk of cardiac dysfunction, heart failure hospitalization, atrial fibrillation, and a higher mortality rate [1–3]. His bundle pacing (HBP), a physiologic pacing strategy, has been developed. When compared to HBP, LBBP has been shown to be effective, feasible, and safe for correcting LBB block and maintaining physiological left ventricle (LV) activation, with a greater success rate and more stable lead parameters [12–16]. Little is known about LBBP in patients with intrinsic right bundle branch block (RBBB) who have pacemaker indications
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
