Presence of His-bundle injury current during permanent His-bundle pacing was associated with significantly lower pacing thresholds at 1 year compared to its absence (1.3 vs 1.98 V, P<0.05).
Observational (n=60)
Does the presence of His-bundle injury current during permanent His-bundle pacing predict lower pacing thresholds in patients requiring pacing?
The presence of a His-bundle injury current during permanent His-bundle pacing is associated with significantly lower short- and long-term pacing thresholds.
Absolute Event Rate: 1.3% vs 1.98%
p-value: p=< 0.05
INTRODUCTION: His-bundle (HB) pacing (P) is a physiological alternative to right ventricular pacing (RVP), but is technically challenging and limited by higher pacing thresholds. Myocardial injury current (IC) recorded during right ventricular lead placement implies good tissue contact and is associated with low-pacing thresholds. IC at the HB has not been previously described. We hypothesized that HBIC during permanent HBP may be associated with lower pacing thresholds. METHODS: Permanent HBP was performed using Medtronic Select Secure(tm) (Medtronic Inc., Minneapolis, MN, USA) delivered via a fixed-curve (C315 His) sheath. HB electrogram (EGM) was recorded in a unipolar fashion from the lead tip. Presence or absence of HBIC was documented. HBP threshold, sensing, and impedances were recorded at implant, 2 weeks, 2 months, and 1 year. RESULTS: Sixty patients (age 72 ± 15 years; male 55%, sick sinus syndrome 40%, atrioventricular block 60%, fluoroscopy duration 9.2 ± 3.7 minutes) underwent successful permanent HBP. HBIC was recorded in 22 (37%) patients (group I). HBEGM without IC was recorded in the remaining 38 (63%) patients (group II). Pacing threshold at implant, 2 weeks, 2 months, and 1 year were significantly lower in group I (1.16 ± 0.4 V; 1.18 ± 0.5 V; 1.23 ± 0.6 V; 1.3 ± 0.6 V @ 0.5 ms) compared to group II (1.75 ± 0.7 V; 1.82 ± 0.8 V; 1.93 ± 0.8 V; 1.98 ± 0.9 V @ 0.5 ms, P < 0.05), respectively. CONCLUSIONS: IC can be recorded at the HB during permanent HBP in 37% of patients. HBIC is associated with significantly lower pacing thresholds compared to patients in whom HBIC was not recorded. HBIC may be a marker for superior short-term HBP thresholds.
Vijayaraman et al. (Wed,) conducted a observational in Sick sinus syndrome or atrioventricular block requiring permanent His-bundle pacing (n=60). Presence of His-bundle injury current (HBIC) vs. Absence of His-bundle injury current was evaluated on Pacing threshold at 1 year (V @ 0.5 ms) (p=< 0.05). Presence of His-bundle injury current during permanent His-bundle pacing was associated with significantly lower pacing thresholds at 1 year compared to its absence (1.3 vs 1.98 V, P<0.05).