Quantitative analysis reveals influencing factors to facilitate successful anodal-ring capture in left bundle branch
Wenzhao Lu1, Jinxuan Lin2, Yao Li1
1State Key Laboratory of Cardiovascular Disease, Arrhythmia Center, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences & Peking Union Medical College, No. 167, Beilishi Road, Xicheng District, Beijing 100037, China.
Insights
Anodal-ring capture during left bundle branch pacing improves right ventricular conduction delay. Lead tip position, specifically longer longitudinal and shorter lateral distances, influences successful anodal-ring capture implementation in patients.
Area of Science:
- Cardiology
- Electrophysiology
- Medical Devices
Background:
- Left bundle branch pacing (LBBP) preserves left ventricular synchrony but can cause right ventricular conduction delay (RVCD).
- Anodal-ring capture (ARC) during bipolar LBBP can mitigate RVCD but is not universally achievable.
- Understanding factors influencing ARC success is crucial for optimizing LBBP outcomes.
Purpose of the Study:
- To identify factors predicting the successful implementation of anodal-ring capture (ARC) during left bundle branch pacing (LBBP).
- To analyze the relationship between lead tip characteristics and ARC achievement.
- To provide insights for improving LBBP procedural success.
Main Methods:
- 105 patients undergoing LBBP with intraoperative ARC testing were analyzed.
- Electrocardiographic parameters (stim-QRSd, stim-LVAT/RVAT, V6-V1 interval) were measured.
- Lead tip site distribution (corrected longitudinal/lateral distance), relative angles, and intraseptal lead length were assessed using echocardiography.
Main Results:
- 62% of patients achieved ARC at a pacing output ≤ 5.0 V/0.5 ms.
- ARC shortened stimulus-to-QRS duration by 13.1 ± 7.5 ms.
- Successful ARC correlated with longer corrected longitudinal lead distance, shorter corrected lateral distance, and better ring-septum contact.
Conclusions:
- Lead tip positioning is a key determinant for successful anodal-ring capture during LBBP.
- Optimizing lead placement can enhance the benefits of ARC in mitigating right ventricular conduction delay.
- These findings offer valuable guidance for clinicians performing LBBP procedures.
Aims:
Left bundle branch pacing (LBBP) maintains left ventricular synchrony but induces right ventricular conduction delay (RVCD). Although anodal-ring capture (ARC) during bipolar LBBP improves RVCD, it is not achieved in all patients receiving LBBP. This study aimed to analyze the factors influencing ARC implementation.
Methods And Results:
Patients receiving LBBP with intraoperative ARC testing were enrolled. Electrocardiographic parameters were measured, including stimulus-to-QRS duration (stim-QRSd), stimulus-to-left/right ventricular activation time (stim-LVAT/RVAT), and V6-V1 interpeak interval. The distribution of lead-tip sites was described as the corrected longitudinal and lateral distance (longit-/lat-dist). Relative angles of the LBBP lead were measured. Echocardiography in short-axis view was used to measure the intraseptal lead length. Intergroup comparisons, correlation analysis, and stepwise logistic regression were performed. In total, 105 patients were included, among which 65 (62%) patients achieved ARC at a pacing output ≤ 5.0 V/0.5 ms (average 3.1 V/0.5 ms). Anodal-ring capture further shortened the stim-QRSd by 13.1 ± 7.5 ms. Better unipolar-ring (cathodal) threshold and R-wave sensing in LBBP-ARC group indicated the critical role of ring-septum contact in ARC. Longer corrected longit-dist and shorter corrected lat-dist of lead-tip sites were positively correlated with higher success likelihood of ARC, likely due to the greater relative angle in which the lead enters the septum and consequently the longer intraseptal lead length and better ring-septum contact.
Conclusion:
This study elucidated the factors affecting the success likelihood of LBBP-ARC. These findings improve the understanding of LBBP-ARC, providing references for future research and clinical practice.
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