Outcomes of His-bundle pacing upgrade after long-term right ventricular pacing and/or pacing-induced cardiomyopathy: Insights into disease progression

Background His-bundle pacing (HBP) is a physiological alternative to right ventricular pacing (RVP). The outcomes of HBP in patients with longstanding atrioventricular block (AVB) and RVP are unknown Objective The purpose of this study was to retrospectively assess the feasibility of HBP in patients with chronic RVP and longstanding AVB and to evaluate its efficacy in reversing the adverse remodeling induced by RVP. Methods HBP was attempted in patients with longstanding AVB and chronic RVP and/or pacing-induced cardiomyopathy (PICM) in need for resynchronization therapy. The site of conduction block and feasibility of HBP was documented. Electrocardiographic and echocardiographic assessments at baseline and follow-up were recorded. Results HBP was successful in 79 of 85 patients (93%) with RVP for 77.6 ± 74.8 months (range 2–540 months). AV nodal block was present in 59 and infranodal block in 26. QRS duration increased from 123 ± 31 ms at baseline to 177 ± 17 ms (P Conclusion Despite a long duration of AVB and chronic RVP, HBP normalized QRS complexes and T waves with stable thresholds, suggesting that progression of distal conduction disease is uncommon in this population. Electrical and structural changes induced by chronic RVP were consistently reversed with HBP.