To identify the changes in the threshold during the follow-up period of His bundle pacing (HBP) and to explore the predictors of threshold elevation.
Methods
Patients with atrioventricular block and ventricular pacing indications or patients with cardiac function deterioration with high ventricular pacing compared to HBP escalation in the Second Department of Arrhythmia in the First Affiliated Hospital of Dalian Medical University from July 2017 to October 2018 were continuously enrolled. The data of patient demographics, comorbidities,indications for pacemaker implantation, echocardiography parameters and electrocardiogram parameters were collected, and follow-up was conducted once at the first, third, sixth, and tweilveth months after the implantation, and every 6 months after 1 year. The pacing threshold, R-wave perception and wire impedance, etc. were recorded during the follow-up. Logistic regression analysis was performed on age, gender, comorbidities, intraoperative injury current, baseline threshold, injury current, right ventricular perception, left ventricular ejection fraction, etc. to evaluate the predictors of HBP threshold elevation. Postoperative threshold elevation was defined as an increase in the pacing threshold of ＞1.0 V from the baseline threshold at postoperative follow-up and reaching more than 2.5 V/0.4 ms.
Results
After 60 (57, 63) months of follow-up, 37 (82.22%,37/45) patients with HBP remained stable and 8 (17.78%, 8/45) patients increased the threshold for His bundle capture. Logistic regression analysis showed that the pacing threshold of patients with intraoperative injury current tended to be stable [odds ratio (OR)=0.121, 95% confidence imterval (CI) 0.014-1.088, P = 0.059], and ventricular perception was statistically significant for the stability of the long-term threshold of HBP (OR=0.635, 95%CI 0.436-0.923, P = 0.017).
Conclusion
Some patients with HBP may have an elevated pacing threshold in the long term, and the pacing threshold is more likely to be stable in patients with high intraoperative injury current and R-wave amplitude.
