Prospective Evaluation of Feasibility, Electrophysiologic and Echocardiographic Characteristics of Left Bundle Branch Area Pacing.

BACKGROUND: His bundle pacing (HBP) is the most physiologic form of pacing but associated with higher thresholds and lower success in patients with His-Purkinje conduction disease. Recent reports have described transvenous left bundle branch area pacing (LBBAP).

OBJECTIVE: We aimed to prospectively evaluate the feasibility, and the electrophysiological and echocardiographic characteristics of LBBAP.

METHODS: Patients requiring pacing for bradycardia or heart failure indications (failed LV lead) were prospectively enrolled. LBBAP was performed with Medtronic 3830 lead. Presence of LBB potential, paced QRS morphology/duration and peak LV activation time (pLVAT) were recorded at implant. Pacing threshold and sensing was assessed at implant and follow-up. Echocardiography was performed to assess the approximate lead location and impact on tricuspid valve function.

RESULTS: LBBAP was successful in 93 of 100 (93%) pts. Mean age 75±13 yrs; men 69%, LBBB 24, RBBB 25, IVCD 8. Indications for pacing-AV block 54, SND 23, AVN ablation 7, CRT 11, HBP lead failure 7. Baseline QRSd was 133±35ms. Paced QRSd 136±17ms. LBB potentials were observed in 63 patients with LB-V interval of 27±6ms. pLVAT was 75±16ms. Pacing threshold at implant was 0.6±[email protected] and R waves were 10±6mV and remained stable at median follow-up of 3 months. The lead depth in the septum was approximately1.4±0.23cm.

CONCLUSIONS: LBBAP was feasible in a high percentage of patients with low thresholds during acute follow-up. HBP and LBBAP may significantly increase the overall success of physiologic pacing.