Kinetics and Disappearance of QRS Transition in Patients Undergoing Left Bundle Branch Pacing - A Novel Method for
Márk Gémesi1,2,3, Balázs Polgár1, Zoltán Gingl1
1Department of Cardiology, Central Hospital of Northern Pest - Military Hospital, Budapest, Hungary.
Journal of Cardiovascular Electrophysiology
|July 11, 2025
Summary
QRS transition during left bundle branch pacing (LBBP) is initially high but decreases over time. This study clarifies QRS transition kinetics and microdislodgement incidence in LBBP patients.
Area of Science:
- Cardiology
- Electrophysiology
- Medical Devices
Background:
- QRS transition during threshold testing confirms Conduction System capture in left bundle branch pacing (LBBP).
- Limited data exists on the temporal kinetics of QRS transition.
- Microdislodgement is a known complication of left bundle branch area pacing (LBBAP).
Purpose of the Study:
- To evaluate the kinetics and disappearance of QRS transition in LBBP patients.
- To assess the diagnostic yield of QRS transition at different time points.
- To characterize the incidence and impact of microdislodgement.
Main Methods:
- Prospective study of patients undergoing successful LBBP.
- Assessment of QRS transition kinetics during intraoperative, postoperative, and follow-up threshold tests.
- Evaluation of microdislodgement based on QRS transition patterns.
Main Results:
- LBBP confirmed in 76.1% of LBBAP patients.
- Intraoperative QRS transition observed in 86.4%, decreasing to 47.0% postoperatively and 33.0% at follow-up.
- LBB capture persisted in 92.0% of cases, with microdislodgement in only 5.0%.
Conclusions:
- QRS transition kinetics in LBBAP show high intraoperative detectability that diminishes postoperatively.
- The study provides insights into the temporal dynamics of QRS transition in LBBP.
- Classification of microdislodgement aids in understanding its influence on pacing outcomes.
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