DIRECT HIS-BUNDLE PERMANENT PACING AS AN ALTERNATIVE TO CONVENTIONAL RIGHT VENTRICULAR APICAL PACING: A PILOT STUDY IN ZAGAZIG UNIVERSITY CARDIAC ELECTROPHYSIOLOGY LABORATORY

Aim: was to evaluate the feasibility of direct his bundle pacing (DHBP) as one of the physiological pacing approaches in our EP lab. Methods: All suitable patients admitted for permanent pacemaker implantation, between January and June 2013, were given a trial for DHBP. Using his bundle (HB) recording through a quadripolar catheter as an electrical and radiological guidance, custom shape stylet was used to direct an active fixation lead to the target position; a pacing protocol was applied to insure pure HB capture. A matching group of patients with apical right ventricular pacing (ARVP) were used as control, to assess the feasibility of DHBP technique. Results: Pure DHBP was successful in 12 out of 32 patients 38%.The DHBP procedure was costly when compared to ARVP in total procedure time (94.7±30.4 vs. 43.2±17.4 minutes), fluoroscopy time(35.2±10.9 vs. 10.1±3.6 minutes), patient x-ray exposure (34.1±7.8 vs. 11.9±4.9 Gy Cm2)and acute pacing threshold (2.1±0.6 vs.0.6±0.4 V). But in the other hand it was better in paced QRS width (76.8±14.8 vs. 193.9±35.8 ms.), patients’ exercise capacity as percentage of achieved METS from Max METS for age (75.5±8.7 vs.54.9±8.7%). the DHBP procedure time was progressively shorter indicating a steep learning curve. Conclusion: Although DHBP has many technical difficulties, it can be achieved with a reasonable coast in our EP lab with a demonstrable benefit, and a steep learning curve. Keywords: direct his bundle pacing, apical right ventricular pacing, physiological pacing, pacemaker, paced QRS duration, and active fixation lead.