Electrophysiological observations of acute His bundle injury during permanent His bundle pacing ☆,☆☆,★ Pugazhendhi Vijayaraman, MD, FHRS, a, ⁎ Gopi Dandamudi, MD, b Kenneth A. Ellenbogen, MD c a Geisinger Wyoming Valley Medical Center, Wilkes-Barre, PA b Indiana University, Indianapolis, IN c Virginia Commonwealth University Health System, Richmond, VA Abstract Background: Permanent His bundle pacing (HBP) is a physiological alternative to right ventricular pacing (RVP). Catheter manipulation during HBP can cause trauma to the His bundle during implantation. We sought to determine acute and long-term incidence of His bundle (HB) injury with HBP. Methods: Patients undergoing permanent HBP at Geisinger Wyoming Valley Medical Center from 2006 to 2014 formed the study group. Patients with pre-existing His-Purkinje disease (HPD) were excluded from the study. Any development of new bundle branch block (BBB) or AV block (B) during acute HBP lead-induced block was recorded. Resolution of AVB and/or BBB was documented. Results: HBP was attempted in 450 patients. In 358 patients without HPD, 28 (7.8%) developed acute HB injury in the form of complete AVB (4, 1.1%), RBBB (21, 5.9%) or LBBB (3, 0.8%) during HBP lead placement. In all 7 patients with AVB or LBBB, conduction completely recovered. The HB electrogram from the lead displayed injury current in all 7 patients. Lead-induced RBBB resolved in 12 of 21 patients and persisted in 9 (2.5%) patients. Pacing from the HBP lead resulted in correction of acute conduction block in 27 of 28 patients and 8 of 9 patients with chronic RBBB. None of the patients with transient conduction block developed new conduction disease during follow-up of 21 ± 19 months. Conclusions: Despite acute trauma to HB in 7.8% of patients undergoing permanent HBP, complete resolution of conduction block occurred in 19 of 28 patients (68%). RBBB persisted in 9 patients (32%) but mostly normalized with HBP. © 2016 Elsevier Inc. All rights reserved. Keywords: His bundle pacing; His bundle injury; Bundle branch block; Complete heart block; Permanent His bundle pacing Introduction RV pacing has been associated with ventricular dyssyn- chrony, reduction in left ventricular ejection fraction and adverse clinical outcomes [1–3]. Permanent His bundle pacing (HBP) is a physiological alternative to right ventricular (RV) pacing. Since the original description of permanent His bundle pacing (HBP) by Deshmukh et al. [4], several investigators have adopted this form of pacing [5–9]. Catheter manipulation during electrophysiology studies or cardiac catheterization has been reported to be associated with transient or permanent bundle branch block [10,11]. However, the impact of targeted placement of HBP electrode on the His-Purkinje conduction system is unclear. The aim of our study is to report the acute and long-term incidence of injury to the His bundle following permanent HBP. Methods Patients Permanent HBP has been performed at Geisinger Wyoming Valley Medical Center since 2006. Our analysis Available online at www.sciencedirect.com ScienceDirect Journal of Electrocardiology 49 (2016) 664 – 669 www.jecgonline.com ☆ Disclosures: PV (Medtronic-Speaker, Boston Scientific-Advisory board); GD (Medtronic-Speaker); KAE (Medtronic-Research, Speaker, Advisory board). ☆☆ Funding: None. ★ Conflicts of Interest: None. ⁎ Corresponding author at: Cardiac Electrophysiology, Geisinger Wyoming Valley Medical Center, MC 36-10, 1000 E Mountain Blvd, Wilkes-Barre, PA 18711. E-mail addresses: pvijayaraman1@geisinger.edu, pvijayaraman@gmail.com http://dx.doi.org/10.1016/j.jelectrocard.2016.07.006 0022-0736/© 2016 Elsevier Inc. All rights reserved.