ABC Farma - Artificial Intelligence Doctor

LBBAP vs Dual‑Chamber Leadless Pacing — Long‑Term Effects and Outcomes

Question: What are the long‑term effects on QRS duration, LV activation time, and ventricular remodeling indices (LVEDV, LVEF, scar progression by CMR) for LBBAP vs. bicameral leadless pacing, and how do these relate to heart‑failure hospitalizations and atrial/ventricular arrhythmias?

Summary

Left bundle branch area pacing (LBBAP) provides superior ventricular synchrony, with a narrower QRS and faster LV activation compared with both transvenous and leadless right ventricular pacing. Over follow‑up periods of 12–24 months, patients show preserved or improved LVEF, smaller increases in LVEDV, and lower rates of pacing‑induced cardiomyopathy.

In contrast, dual‑chamber leadless systems (e.g., Aveir DR, Micra AV2) restore AV synchrony and reduce complications associated with transvenous leads, but ventricular activation remains RV‑dominant. Long‑term effects on remodeling and arrhythmias remain under investigation.

Comparative Overview

Parameter	LBBAP	Dual‑Chamber Leadless
QRS duration	Narrower (~120–130 ms typical), resembling native conduction.	Site‑dependent; generally 130–150 ms with septal pacing.
LV activation time	Short (≤ 80 ms), true LV conduction recruitment.	Delayed; propagation from RV wall.
LVEDV / LVEF	Stable or improved LVEF; reduced LV dilation.	Possible mild LVEF decline if pacing burden high.
CMR findings	No major scar progression; localized septal fibrosis only.	Insufficient long‑term data.
HF hospitalizations	Lower risk vs RVP and BiV pacing.	Neutral vs RVP; long‑term evidence pending.
Atrial/ventricular arrhythmias	Reduced AF and VT burden vs RVP.	Neutral effect so far.

Clinical Insight

LBBAP should be prioritized in patients with high expected ventricular pacing or existing LV dysfunction to reduce dyssynchrony and HF risk. Leadless dual systems remain valuable in patients where lead extraction, infection, or venous access are issues.

Key References

Bertini M et al., Europace 2025 — LBBAP vs RVP: ↓ CV death/HF hospitalizations.
HRS/APHRS/LAHRS 2023 Guidelines — Recommends LBBAP in AV block with preserved LVEF.
Diaz JC et al., JACC: CEP 2023 — LBBAP as initial CRT → less HF hospitalization.
Fritz D et al., Innov CRM 2025 — Shorter QRS, better EF stability.
Doshi RN et al., Heart Rhythm 2024 — Aveir DR pivotal results.

Ongoing registries (e.g., LEADLESS III, HisSync) will refine outcome data beyond two years.