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.