Left Bundle Branch Area Pacing guided by Continuous Uninterrupted
Monitoring of the unipolar Pacing Characteristics.
Abstract
Introduction. During left bundle branch area pacing (LBBAP) lead
implantation, intermittent monitoring of unipolar pacing characteristics
validates LBB capture and can detect septal perforation. We aimed to
demonstrate that continuous uninterrupted unipolar pacing from an
inserted lead stylet (LS) is feasible and facilitates LBBAP
implantation. Methods. Thirty patients (mean age 76 ± 14 years) were
implanted with stylet-driven pacing lead (Biotronik Solia S60). In 10
patients (validation-group) conventional, interrupted implantation was
performed, with comparison of unipolar pacing characteristics between LS
and connector-pin (CP)-pacing after each rotation step. In 20 patients
(feasibility-group) performance and safety of uninterrupted implantation
during continuous pacing from the LS were analyzed. Results. In the
validation-group, LS and CP-pacing impedances were highly correlated
(R2=0.95, p<0.0001, bias 12±37Ω). Pacing
characteristics from LS and CP showed comparable sensed electrograms and
paced QRS morphologies. In the feasibility-group, continuous LS-pacing
allowed beat-to-beat monitoring of impedance and QRS morphology to guide
implantation. This resulted in successful LBBAP in all patients, after a
mean of 1±0 attempts, with mean threshold 0.81 ± 0.4V, median sensing
6.5mV [IQR 4.4-9.5] and mean impedance 624 ± 101Ω, and positive
LBBAP-criteria with median paced QRS duration 120ms [IQR 112-152ms]
and median pLVAT 73ms [IQR 68-80.5ms]. No septal perforation
occurred. Conclusion. Unipolar pacing from the LS allows accurate
determination of pacing impedance and generates similar paced QRS
morphologies and equal sensed electrograms, compared to CP pacing.
Continuous LS pacing allows real-time monitoring of impedance and paced
QRS morphology, which facilitates a safe and successful LBBAP lead
implantation.