Battery longevity and His bundle lead performance in His bundle pacing

High capture thresholds and lead dislodgment are often cited as impediments for general adoption of His bundle pacing.

We report on our experience in managing patients who underwent His bundle pacing with higher energy requirement and incidence of lead dislodgment in a mean duration of 33 months.

In 1188 patients, pacing was done at the site of His bundle electrogram and capture of conduction axis was confirmed by paced complex demonstrating normal or more normal QRS voltage, QRS axis, and ventricular activation time. Patients were followed for 33 months with routine programming changes to optimize battery longevity.

His bundle pacing thresholds revealed a small but significant increase in His bundle capture (from 1.1 ± 0.8 to 1.3 ± 0.8 [P < .001]). However, with optimization of pulse duration and pacing polarity, the capture threshold energy for the group, $E=\left(V^{ˆ}2\times pw\right)/R\text{,}$ remained unchanged at 0.003 mJ from 4 weeks to 33 months. Two volts or higher threshold was found in 92 patients (11%) at 4 weeks and in 151 patients (16%) at 33 months. The average predicted battery life was 8.5 years. Lead dislodgment occurred in 15 patients (1.2%).

In His bundle pacing, the increase in capture threshold over time can be managed by optimizing pacing pulse duration and polarity. The dislodgment rates of Medtronic 3830 lead are not unlike those reported for myocardial pacing. Our study calls attention to the >2 V threshold in 16% of patients and the need for higher output pacemaker batteries.