Introduction:
Focal disease in the main body of the His bundle (HB) is the cause for majority of the bundle branch block (BBB) patterns on EKG. Temporary distal HB pacing (HBP) has previously been shown to correct BBB in high number of patients. Anecdotal reports have confirmed abolition of BBB by permanent HBP.
Hypothesis:
The aim of our study is to report the incidence of correction of BBB during permanent HBP in patients undergoing pacemaker (PM) implantation.
Methods:
Permanent HBP was attempted in 185 patients referred for PM implantation. Pts with QRS duration (d) ≥110 ms and BBB were included in the study. Pts with normal QRS or CHB were excluded. HBP was performed using the Medtronic SelectSecure 3830 pacing lead. Baseline QRSd, paced QRSd, correction of BBB and HB pacing threshold were recorded.
Results:
Fifty patients met the inclusion-exclusion criteria. Mean age 73±12 yrs; men 65%, HTN 81%, DM 30%, CAD 38%, AF 42%, SSS 39%, AV disease 61%, RBBB 31, LBBB 14, IVCD 5). Permanent HBP was successful in correcting BBB in 42 (84%) patients. Underlying BBB was corrected by HBP in 29 of 31 (94%) patients with RBBB; 11 of 14 (79%) patients with LBBB; 1 of 5 (20%) patients with IVCD. Baseline QRSd improved from 141±15 ms to 124±17 ms. HBP threshold at implant was 1.5±1.3 V @ 0.5 ms.
Conclusions:
Permanent HBP corrected underlying BBB in the vast majority of patients with right or left BBB (40 of 45, 89%) compared to only 1 of 5 (20%) patients with IVCD. This confirms that focal disease in the main HB is the cause for BBB in the patients referred for PM implantation.
Permanent His-bundle pacing using stylet-directed, active-fixation leads placed via coronary sinus sheaths compared to conventional lumen-less system
