title: A feasible approach for direct his-bundle pacing using a new steerable catheter to facilitate precise lead placement.
abstract: BACKGROUND
  Much clinical evidence has shown that right ventricular (RV) apical pacing is detrimental to left ventricular function. Preservation of the use of the His-Purkinje (H-P) system may be ideal in heart block that is restricted to the AV node, but may be of no benefit when H-P disease exists.
  
  
  OBJECTIVE
  To investigate the feasibility of direct His-bundle pacing (DHBP) using a new system consisting of a steerable catheter and a new 4.1 F screw-in lead.
  
  
  METHODS
  Between May and December 2004, 26 patients (19 male, mean age: 77 +/- 5 years) with a standard pacemaker (PM) indication and preserved His-bundle conduction were enrolled and DHBP was attempted.
  
  
  RESULTS
  DHBP was achieved in 24 patients (92%); two patients were paced in the His area, but the paced QRS morphology and duration were different from the native QRS. The mean time for lead positioning was 19 +/- 17 minutes, the mean fluoroscopy time was 11 +/- 8 minutes, and the total procedure time (skin-to-skin including positioning of a quadripolar diagnostic catheter for His recording) was 75 +/- 18 minutes. In DHBP pacing, the acute pacing threshold was 2.3 +/- 1.0 V at a pulse duration of 0.5 msec, and the sensed potentials were 2.9 +/- 2.0 mV. At a 3-month follow-up examination, the same QRS duration and morphology recorded on implantation were observed in all patients. The pacing threshold was 2.8 +/- 1.4 V, and sensed potentials were 2.5 +/- 1.8 mV; the sensing configuration was changed from bipolar to unipolar in 6 patients to resolve undersensing issues. No major complications were observed.
  
  
  CONCLUSIONS
  This feasibility study shows that DHBP can be accomplished with a new system consisting of a steerable catheter and an active fixation lead in 92% of the patients in whom it was attempted.
authors.affiliation: Division of Cardiology, Rovigo General Hospital, Rovigo, Italy. franc.zanon@iol.it
authors.forename: Francesco
authors.initials: F
authors.lastname: Zanon
authors.forename: Enrico
authors.initials: E
authors.lastname: Baracca
authors.forename: Silvio
authors.initials: S
authors.lastname: Aggio
authors.forename: Gianni
authors.initials: G
authors.lastname: Pastore
authors.forename: Graziano
authors.initials: G
authors.lastname: Boaretto
authors.forename: Paola
authors.initials: P
authors.lastname: Cardano
authors.forename: Tiziana
authors.initials: T
authors.lastname: Marotta
authors.forename: Gianluca
authors.initials: G
authors.lastname: Rigatelli
authors.forename: Mariapaola
authors.initials: M
authors.lastname: Galasso
authors.forename: Mauro
authors.initials: M
authors.lastname: Carraro
authors.forename: Pietro
authors.initials: P
authors.lastname: Zonzin
mesh_terms: D000368:Aged; D002036:Bundle of His / Q000503:physiopathology*; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D004562:Electrocardiography; D004566:Electrodes; D004867:Equipment Design; D005240:Feasibility Studies; D005260:Female; D005471:Fluoroscopy; D005500:Follow-Up Studies; D006327:Heart Block / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy*; D006801:Humans; D008297:Male; D010138:Pacemaker, Artificial; D012189:Retrospective Studies; D016896:Treatment Outcome