Safety and feasibility of conduction system pacing in patients with congenital heart disease

Introduction: Conduction system pacing (CSP) has emerged as an ideal physiologic pacing strategy for patients with permanent pacing indications. We sought to evaluate the safety and feasibility of CSP in a consecutive series of unselected patients with congenital heart disease (CHD). Methods: Consecutive patients with CHD in which CSP was attempted were included. Safety and feasibility, implant tools and electrical parameters at implant and at follow-up were evaluated. Results: A total of 20 patients were included (10 with a previous device). Ten patients had complex forms of CHD, 9 moderate defects and 1 a simple defect. His bundle pacing (HBP) or left bundle branch area pacing (LBBAP) were achieved in all patients (10 HBP, 5 LBBP and 5 left ventricular septal pacing). Procedure times and fluoroscopy times were prolongued (126±82 min and 27±30 min, respectively). CSP lead implant times widely varied ranging from 4 to 115 minutes, (mean 31±28 min) and the use of multiple delivery sheaths was frequent (50%). The QRS width was reduced from 144±32 ms at baseline to 116±16 ms with CSP. Implant electrical parameters included: CSP pacing threshold 0.85±0.61V; R wave amplitude 9.8±9.2mV and pacing impedance 735±253 Ohms, and remained stable at a median follow-up of 478 days (IQR 225-567). Systemic ventricle systolic function and NYHA class (1.50±0.51 vs 1.10±0.31; p=0.008) significantly improved at follow-up. Lead revision was required in one patient at day-4. Conclusions: Permanent CSP is safe and feasible in patients with CHD although implant technique is complex.