https://doi.org/10.1007/s00392-025-02625-4
1Herz- und Diabeteszentrum NRW Klinik für Elektrophysiologie/ Rhythmologie Bad Oeynhausen, Deutschland; 2Herz- und Diabeteszentrum NRW Klinik für Thorax- und Kardiovaskularchirurgie Bad Oeynhausen, Deutschland; 3Marienhospital Osnabrück Klinik für Innere Medizin / Kardiologie und Intensivmedizin Osnabrück, Deutschland; 4Herz- und Diabeteszentrum NRW Klinik für Kardiologie Bad Oeynhausen, Deutschland
Background: LBBAP has emerged as an alternative to cardiac stimulation via right ventricular pacing and cardiac resynchronization therapy using coronary sinus leads. The approach utilizes dedicated three-dimensional guiding catheters for lead placement. Procedural complexity and high costs for specialized implantation tools may prevent broader use of this technique.
Aim: Our objective was to evaluate the feasibility and safety of implantation of a LBBAP electrode without a dedicated guiding catheter.
Methods: This was a single centre proof-of-concept evaluation. Two different physicians implanted the devices. Patients in whom a dual-chamber pacemaker was indicated were consecutively included. The predefined inclusion criteria were an LVEF greater than 40% and an expected high ventricular pacing rate.
All patients received ventricular lead placement with a commercially available stylet-driven pacemaker lead. In all patients LBBAP was attempted without the use of a dedicated guiding catheter. For implantation the lead was first introduced through the tricuspid valve into the pulmonary artery. Then it was switched to a stylet that was prebent in three dimensions (Figure 1). The location of the summit of the tricuspid valve was estimated based on the movement of the inserted electrode in a 20° RAO projection and detection of annulus signals in unipolar sensing. Afterwards the electrode was withdrawn 15-35mm in apical direction from the tricuspid valve. Septal positioning was achieved by rotating the electrode counterclockwise. The attempted location of septal penetration was defined by the morphology of the unipolar stimulated QRS complex with expected discordance in leads II/III and a nadir notch in V1. The electrode was screwed into the septum by rotating it clockwise while fixing the stylet. It was advanced until a right bundle branch block-like morphology developed in V1 (Qr/QR/qR). The V6 RWPT and the V6 -V1 interpeak interval were measured as described previously. A 3-month follow-up was carried out after the procedure.
Results: A total of 24 patients (8 females, age 72.9±15.1 years, LVEF 54±8%, 19 patients with higher degree AV block, 5 with binodal disease or brady-tachy-syndrome) were included. The procedure and fluoroscopy durations were 60±12 and 7.1±3.6 minutes. LBBAP lead placement was successful in 19 patients (79%), no predictors for failure could have been identified. In these 19 patients the V6-R-wave peak time was 74±11 ms, the V1V6 interpeak interval was 51±11 ms and QRS width during unipolar Stimulation was 123±14 ms. The pacing-threshold was 0.54±0.15 V/0,5 ms; pacing impedance was 470±106 Ohm and sensing was11.1±4.7 mV. One patient experienced dislocation of the atrial lead, and another required revision of the pacemaker pocket. No complications attributed to the transseptal route of the pacing lead occurred.
After a mean follow-up of 104±20 days there was no significant change in QRS widths (123±15 ms, p=0.94), V6-R wave peak time (70±11 ms, p=0.3) and V1V6 interpeak interval (44.7±9.7 ms; p=0.12). The stimulation impedance dropped significantly (390±68 Ohm, p=0.01), however, this was not associated with a significant change in pacing-threshold or sensing values.
Conclusion: Implantation of a LBBAP electrode without the use of a dedicated three-dimensional sheath is feasible and safe in a proportion of patients. Further studies are necessary to define the impact of this technique for clinical use in routine.