Exploring Mechanical Synchrony and Myocardial Work Across Different Pacing Locations Within the Left Bundle Branch
Manuel Tapia Martínez1, Álvaro Estévez Paniagua2, Ana Sánchez Hernández2
1Cardiology Department, Hospital Central de la Defensa Gómez Ulla, Madrid, Spain.
JACC. Clinical Electrophysiology
|March 6, 2026
Summary
Left bundle branch pacing (LBBP) provides physiological activation, and pacing location does not significantly alter mechanical synchrony or work efficiency in patients with preserved left ventricular function. This supports focusing on conduction system capture over specific anatomical targets.
Area of Science:
- Cardiology
- Electrophysiology
- Cardiac Mechanics
Background:
- Left bundle branch pacing (LBBP) offers physiological cardiac activation.
- The impact of LBBP pacing site on mechanical synchrony and efficiency is not well understood.
Purpose of the Study:
- To determine if left ventricular (LV) mechanical performance differs across various LBBP sites.
- To assess if LBBP-paced mechanical synchrony mimics intrinsic LV activation.
Main Methods:
- Prospective cohort study of 114 patients with preserved LV ejection fraction undergoing LBBP.
- Echocardiographic analysis of strain and myocardial work parameters.
- Within-patient comparison of intrinsic rhythm versus LBBP in select patients.
Main Results:
- Central LBB capture in 56.6% and peripheral in 43.4% of 106 patients.
- No significant differences in global longitudinal strain or myocardial work indices between central and peripheral LBBP.
- LBBP did not significantly alter global work efficiency or indices compared to intrinsic rhythm.
Conclusions:
- Mechanical synchrony and work efficiency are consistent across different LBBP sites in patients with preserved LV ejection fraction.
- Findings advocate for a pragmatic approach prioritizing conduction system capture in LBBP.
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