Introduction: His bundle pacing (HBP) may have a role as an alternative approach to conventional right ventricular pacing in bradycardia and AV node ablation, and for patients with heart failure who require cardiac resynchronisation therapy. There are concerns from the literature with changes in HBP threshold over time.
Methods: Patients implanted between 2017 and 2020 with a Medtronic Select Secure model 3830 lead were included in this retrospective study. Data collected included HBP thresholds documented at implant and at latest on-site device check.
Results: A total of forty-one patients were included for data analysis (58% male and mean age 69 ± 9.4 years). Device indications were 24% for bradycardia, 24% for AV node ablation and 52% for heart failure. Nine were PPMs, sixteen were CRTPs and sixteen were CRTDs. Mean follow up was 12.5 ± 8.5 months. There were no implant complications. Mean HBP threshold (analysed at a pulse width of 1 ms) at implant was 1.45 ± 0.95 V and at last follow up 1.49 ± 1.2 V. Mean change in HBP threshold from implant to follow up was 0.04 ± 1.24 V (p=0.832). An increase in HBP threshold of greater than 1V over follow up was seen in ten patients (24%). Loss of His-bundle capture at follow-up was seen in four patients (10%) and in one further patient there was lead failure due to rise in impedance.
Conclusion: In the majority of patients, HBP capture thresholds were stable over follow up. Lead failure rate is similar to that described in the literature.1 Further multicentre studies are needed to evaluate threshold changes over time.