Abstract Introduction Left bundle branch area pacing (LBBAP) has become increasingly popular due to the relatively simple implantation procedure allowing for conduction system pacing (CSP). Initially, lumen-less leads have been used primarily for CSP. However, several authors have published encouraging results using conventional stylet-driven pacemaker (PM) leads as well and our centers have largely adopted this approach. Methods In our two tertiary referral centers, we assessed all patients, who underwent a LBBAP lead implantation using any lead. We observed several early lead fractures, exhibiting a unique failure mechanism, which we illustrate in this case-series. Results Between January 2022 and November 2023 343/393 patients (87.3%) were implanted with a Solia pacemaker lead, 46/393 (11.7%) received a SelectSecure 3830 lead, and 4/393 (1.0%) another stylet-driven lead. Three patients (0.8%) who initially were implanted with a Solia lead experienced very early intracardiac lead fractures within 1, 11 and 13 months after implantation despite good initial electrical performance values (Table shows initial values and values during the time of failure (bold)). The first case was a 54 year-old woman with permanent 3d degree AV block receiving an LBBAP lead after lead extraction. Four weeks later, she presented with presyncope and exit block at maximum output in uni- and bipolar configuration. The second case was a 72 year-old man with intermittent 3rd degree AV block in the context of an ischemic heart disease. He received a dual-chamber LBBAP PM. 13 months after the implantation, a bipolar impedance > 2’500Ω and exit block were noted. The third case was 65 year-old man suffering from sick sinus syndrome. He initially underwent a dual-chamber PM implantation in 2011 and due to ventricular sensing issues a transvenous lead extraction and implantation of a LBBAP lead in October 2022. During device follow-up after 11 months, a fractured LBBAP lead with bipolar impedance >2’500Ω and exit block during threshold testing was noticed. In all cases, X-rays and macroscopic analysis consistently showed a disintegration of the lead immediately distal to the ring electrode (Figure; site of fracture marked with an arrow). Most likely, this was caused by the repetitive shear stress at the hinge point of the lead where it is entering the septum. Conclusion No dedicated stylet-driven CSP lead is available to date. The implantation site and technique for LBBAP may exert higher mechanical stress on the distal part of the lead, making it more prone to fracture than in a conventional position. Currently, the use of conventional stylet-driven leads is still off-label and the performance of such leads should be monitored closely.TableFigure