Accelerated idioventricular rhythm after left bundle branch pacing lead implantation.

Premature ventricular contractions with right bundle branch block morphology induced during left bundle branch (LBB) pacing (LBBP) lead implantation serve as a marker indicating that the lead is close to or has reached the LBB region. However, no reports to date have described accelerated idioventricular rhythm (AIVR) induced by LBBP lead deployment. We herein describe a patient who underwent LBBP for complete atrioventricular block. The patient's intrinsic escape rhythm was overtaken by AIVR induced immediately after LBBP lead deployment. AIVR is another marker indicating that the lead has reached the LBB region.