Left Bundle Branch Area Pacing in Patients With Cardiac Sarcoidosis

Left bundle branch area pacing (LBBAP) offers a physiological alternative to traditional pacing and has shown benefit across cardiomyopathy phenotypes. In cardiac sarcoidosis (CS), in which septal inflammation and scarring are common, the performance and clinical impact of LBBAP remain unclear.

The aim of this study was to evaluate procedural success, lead performance, and outcomes of LBBAP in patients with CS.

This study retrospectively identified patients with CS who underwent LBBAP from January 2020 to March 2024 at a single tertiary center. CS was defined per Heart Rhythm Society criteria using histologic or imaging-based evidence. Procedural metrics, device parameters, and echocardiographic data were assessed at baseline and follow-up. LBBAP was confirmed by using European Heart Rhythm Association criteria.

Nineteen patients met inclusion criteria (mean age 59 ± 12 years; 21% female). Atrioventricular block was the most common indication (58%). Septal involvement was seen in 53% (cardiac magnetic resonance imaging) and 61% (positron emission tomography). LBBAP was successful in all patients without acute complications. Baseline paced QRS duration was 139 ± 25 milliseconds; mean threshold was 0.75 ± 0.26 V, R-wave amplitude 15.2 ± 6.3 mV, and impedance 738 ± 208 Ω. Over a 437-day median follow-up, lead parameters remained stable. Among patients with LBBB, QRS >130 milliseconds, and left ventricular ejection fraction (LVEF) <50% (n = 4), LVEF improved from 27% ± 17% to 50% ± 12% (P = 0.06). No differences in pacing parameters were seen based on septal involvement.

LBBAP in CS is feasible and provided stable long-term lead performance in this cohort. Larger studies are needed to assess its clinical benefit in the presence of septal inflammation and fibrosis.