Permanent direct his bundle pacing does not induce ventricular dyssynchrony unlike conventional right ventricular apical pacing An intrapatient acute comparison study Domenico Catanzariti & Massimiliano Maines & Claudio Cemin & Gianpaolo Broso & Tiziana Marotta & Giuseppe Vergara Received: 8 June 2006 / Accepted: 10 July 2006 / Published online: 18 November 2006 # Springer Science + Business Media, LLC 2006 Abstract Background Benefits of A-V synchrony during right ventric- ular apical pacing are neutralized by induction of ventricular dyssynchrony. Only a few data are reported about direct His bundle pacing influence on ventricular synchronism. Aim Was to assess the capability of direct His bundle pacing to prevent pacing-induced ventricular dyssynchrony comparing DDD- (or VVI- in case of Atrial Fibrillation) right ventricular apical pacing with DDD- (or VVI-) direct His bundle pacing in the same patients cohort. Methods 23 of 24 patients (mean age 75.1± 6.4 years) with narrow QRS (HV< 65 ms) underwent permanent direct His bundle pacing for “brady–tachy syndrome” (11) or supra- Hisian II/III-degree AV Block (permanent atrial fibrillation 7, AV Node ablation 1). A 4.1 F screw-in lead was fixed in His position, guided by endocardial pacemapping and unipolar recordings. Additional permanent (13 patients) or temporary right ventricular apical pacing leads were also positioned. Inter- and left intra-ventricular dyssynchrony, mitral regurgitation and left systolic ventricular function Tei index were assessed during either direct His bundle pacing or right ventricular apical pacing. Results Permanent direct His bundle pacing was obtained in 23 of 24 patients. Indexes of ventricular dyssynchrony were drastically reduced, mitral regurgitation decreased and left systolic ventricular function Tei index improved during direct His bundle pacing (or His bundle and septum pacing) in comparison to apical pacing (p < 0.05). No statistically significant differences were observed between direct His bundle pacing and combined His bundle and septum pacing. Conclusion Direct His bundle pacing (also fused with adjacent septum capture) prevents pacing-induced ventric- ular dyssynchrony. Keywords His bundle pacing . His bundle . Brady . Tachy sick sinus syndrome . SupraHisian AV block . Cardiac pacing . Ventricular dyssynchrony Abbreviations RVAP right ventricular apical pacing HP His bundle pacing Hb His bundle PHP para-Hisian pacing H+SP combined pacing of both Hb and adjacent ventricular septum AV atrio-ventricular RV right ventricular LV left ventricular PM pacemaker AVB atrioventricular block ICD implantable cardioverter defibrillator CRT cardiac resynchronization pacing therapy LBBB left bundle branch block J Interv Card Electrophysiol (2006) 16:81–92 DOI 10.1007/s10840-006-9033-5 Mrs. Tiziana Marotta is an employee of Medtronic inc. who gave her assistance during the implantation procedure. D. Catanzariti (*) : M. Maines : C. Cemin : G. Broso : G. Vergara Divisione di Cardiologia, Ospedale S. Maria del Carmine, Corso Verona, n. 4, 38068, Rovereto, TN, Italy e-mail: domenico.catanzariti@apss.tn.it T. Marotta Medtronic Italy, Inc., Milan, Italy