Results of permanent lead implantation at the His bundle without the use of an electrophysiological unit

Abstract

Background His bundle pacing (HBP) promises physiological cardiac stimulation using the conduction system for a synchronous ventricular excitation, excluding the risk of pacing-induced cardiomyopathy. In daily practice, HBP is rather rarely used in Germany, in part because it has been recommended to use an electrophysiological unit (EPU) for registration of the His bundle potential and the HV interval. We attempted HBP replacing the EPU by a normal pacing system analyzer (PSA) with high resolution of the electrogram (EGM) which is used during daily clinical routine (Figs. 1 & 2). Methods Consecutive patients (pts) with attempted HBP in our department were included in this prospective study. We used a 4,1F and a 7F lead together with specific sheaths to reach the His bundle. Mapping was performed using a conventional PSA (atrial channel, unipolar mode, 20 mm/mV). We recorded the success of the implantation for HBP, selective versus non-selective His bundle capture, parameters of sensing and pacing performance, operation and fluoroscopy times, the number of lead implantation attempts and QRS duration before and after HBP. Results Implantation of a system for HBP was attempted in 265 pts (mean age 78±12 years, 102 female, mean left ventricular ejection fraction 55±8%) and was successful in 244 (92%), selective His bundle capture was achieved in 55%, non-selective in 37%. Implantation success rates increased from 86% (earliest quartile) to 98% (latest quartile). Mean operation time was 95±46 min, mean fluoroscopy time 11±10 min; a mean of 6±7 attempts (median: 3) were necessary. Mean R wave amplitude was 5±4 mV, mean threshold 0,7±0,5 V at 1,0 ms. QRS duration before implantation was 111±29 ms, post implantation 88±20 ms. Conclusions HBP in daily clinical routine can be successful in >90% of cases without an EPU. Mean operation and fluoroscopy times were similar to those needed for biventricular pacing. An extremely narrow paced QRS could be achieved that indicates extremely good synchronization with HBP. Funding Acknowledgement Type of funding sources: None.