Permanent His-bundle pacing for cardiac resynchronization therapy: Initial feasibility study in lieu of left ventricular lead

BACKGROUND Permanent His-bundle pacing (HBP) has the potential to physiologically normalize wide QRS duration in patients with bundle branch block and cardiomyopathy. OBJECTIVE The purpose of this study was to assess the feasibility of incorporating a His-bundle lead for cardiac resynchronization therapy (CRT) in lieu of a coronary sinus lead. METHODS Patients with an indication for CRT (n = 21) underwent attempted implantation of an HBP placed into the left ventricular (LV) lead port. Intracardiac intervals, QRS duration, New York Heart Association functional class, ejection fraction (EF), echocardiography, and lead characteristics were measured at baseline and at follow-up. RESULTS Of the 21 patients in whom implantation was attempted, HBP was successfully implanted in 16 (age 62 +/- 18 years, 4 females, EF 25 +/- 8). A significant reduction in mean QRS was observed, with narrowing from 180 +/- 23 ms to 129 +/- 13 ms (P<0001). During the follow-up period, median New York Heart Association functional class improved from III to II (P<001), and mean LV EF and left ventricular internal dimension in diastole (LVIDd) improved from 27% 6 10% to 41% 6 13% (P< 001) and from 5.4 +/- 0.4 cm to 4.5 +/- 0.3 cm (P<001), respectively. At median 12-month follow-up, no dislodgments were observed, and only one patient lost nonselective capture that resolved with increased pacing output. CONCLUSION Permanent HBP is feasible for patients with an indication for CRT using the LV port in lieu of a coronary sinus lead. In this initial experience, narrowing of QRS duration was achieved in 76% of patients with bundle branch block, and improvements in clinical and echocardiographic measures were observed with HBP. Future prospective comparative studies with HBP to achieve CRT are justifiable.