Upgrade to his bundle pacing in pacing-dependent patients referred for pulse generator change: Feasibility and intermediate term follow up.

BACKGROUND: Right ventricular pacing (RVP) is associated with an increased incidence of heart failure and may impair cardiac function. Permanent His bundle pacing (HBP) has the potential to physiologically preserve and prevent cardiac dysfunction. This study was to evaluate the feasibility and intermediate follow-up results of upgrade to HBP implantation in patients referred for pulse generator change with long term RVP.

METHODS: Twelve of 14 pacing dependent patients who were referred for pulse generator exchange underwent upgrade into HBP successfully in our center. QRS duration, New York Heart Association (NYHA) functional class, echocardiography, use of diuretics and lead parameters were measured at baseline and during the follow-up.

RESULTS: Among the 12 patients attempted (mean age, 70.8 ± 8.9 years, 75% males) successfully, the average ejection fraction (EF) was 52.2 ± 11.2%. Nine of 12 patients underwent upgrade to HBP, and three patients with EF < 40% underwent HBP and biventricular pacing (BVP) as well. A significant reduction in mean QRS duration was observed compared with pre-implantation, from 157.8 ± 13.3 ms to 109.3 ± 16.9 ms (p < 0.001). After 6 months follow-up period, median NYHA functional class was improved from 2.7 ± 0.6 to 1.8 ± 0.6 (p = 0.007) and left ventricular internal diastolic diameter (LVIDd) was reduced from 5.5 ± 0.4 cm to 5.3 ± 0.3 cm (p = 0.03).

CONCLUSIONS: HBP improves heart failure symptoms with preserved EF by long term RVP. Permanent HBP is feasible and safe for upgrade in patients with long term RVP irrespective of LVEF.