# Left Bundle Branch Area Pacing in Cardiac Resynchronization Therapy: How Does It Compare to Biventricular Pacing in Terms of Electrocardiographic Parameters and Procedural Outcomes?

## TL;DR

This study compares two pacing methods for heart failure treatment and finds that left bundle branch area pacing offers better results than traditional biventricular pacing.

## Contribution

The study provides new comparative data on electrocardiographic and procedural outcomes between LBBAP-CRT and BVP-CRT.

## Key findings

- LBBAP-CRT resulted in greater QRS narrowing and lower pacing thresholds compared to BVP-CRT.
- LBBAP-CRT had no complications, while BVP-CRT had complications in 18.1% of patients.
- LBBAP-CRT was associated with optimal pacing thresholds and lower E/e′ ratio and lead impedance.

## Abstract

Background/Objectives: Biventricular pacing (BVP) to deliver cardiac resynchronization therapy (CRT) is a standard intervention for heart failure, yet suboptimal response remains common due to challenges in left ventricular (LV) lead placement. Left bundle branch area pacing (LBBAP) has emerged as a promising alternative, offering physiological activation via direct conduction system engagement. However, comparative data on electrocardiographic (ECG) and procedural outcomes between LBBAP-CRT and BVP-CRT are limited. Methods: This retrospective, single-center study compared LBBAP-CRT and BVP-CRT in 114 patients with left bundle branch block and LV ejection fraction ≤ 35%. LBBAP-CRT was performed using a Medtronic SelectSecure™ 3830 lead via a fixed-curve sheath Medtronic C315HIS, with successful capture confirmed by ECG criteria (Qr/qR in V1, LV activation time < 100 ms). BVP-CRT involved coronary sinus LV lead placement. Outcomes included QRS duration, pacing thresholds, complications, and procedural metrics. Statistical analysis employed logistic regression to identify predictors of optimal pacing thresholds (≤1.0 V at 0.5 ms). Results: LBBAP-CRT yielded greater degree of QRS narrowing than BVP-CRT (136.7 ± 13.5 ms vs. 147.2 ± 14.6 ms, p < 0.001) and lower pacing thresholds (p < 0.05). Complications occurred in 18.1% of BVP-CRT patients (phrenic nerve stimulation, lead dislocation) versus none in LBBAP-CRT (p = 0.011). According to the multivariable analysis LBBAP-CRT was associated with an optimal thresholds (p = 0.007), alongside lower E/e′ ratio and lead impedance. Conclusions: LBBAP-CRT was associated with superior electrical resynchronization, fewer complications, and better pacing thresholds compared to BVP, suggesting its potential as a preferred CRT strategy. Larger randomized trials are needed to validate long-term outcomes.