Lead Advancement Using Only a Stylet-Driven Lead and Stylet Without a Delivery Catheter: Aiming for Left Bundle...

Left bundle branch area pacing (LBBAP) using a delivery catheter has become popular for achieving physiologic pacing, since lead advancement requires backup support, which is usually provided by a delivery catheter. However, traditional stylet shaping offers the advantage of flexible pacing site selection. Therefore, in this study, we investigated whether LBBAP can be performed using traditional stylet shaping.

We retrospectively reviewed 12 cases at our institution that underwent pacemaker implantation without using a delivery catheter, aiming to achieve LBBAP. Right ventricular (RV) angiography was performed, and the pacing site was selected using a conventional three-dimensional (3D) shaping stylet in the central region of the right ventricle, which was divided into nine segments, targeting a stimulated left ventricular activation time (LVAT) ≤ 80 ms. Next, we switched to a two-dimensional (2D) shaping stylet to achieve passive backup and performed lead advancement by rotating the lead body without pushing the stylet. We compared the LVAT, QRS width, and lead parameters over time.

LVAT was significantly shortened from helix deployment (77.2 ± 10.7 ms) to body turn (71.5 ± 13.2 ms) (p = 0.00016) and further shortened by one week (62.5 ± 13.6 ms) (p = 0.0022).

By modifying the stylet-shaping curve and technique, lead advancement into the myocardium was feasible without using a delivery catheter. Although this study did not meet the strict criteria for LBBAP, our findings suggest that catheter-free LBBAP may be achievable with refined stylet shaping and standardized techniques.