title: Backup right ventricular pacing with a 0.035'' guidewire during implantation of left ventricular leads.
abstract: BACKGROUND
  During implantation of biventricular devices, manipulation of the guiding sheath during localization of the coronary sinus (CS) ostium may result in injury to the right bundle and complete heart block. A preventive measure is to implant the right ventricular (RV) lead first, though this may interfere with manipulation of the guiding sheath and dislodge the permanent lead. We tested the feasibility of backup pacing with a 0.035'' guidewire, advanced through the guiding sheath during CS localization.
  
  
  METHODS
  One hundred six consecutive patients (mean age = 70 +/- 11 years, 81 men) undergoing biventricular device implantation were studied. A 0.035'' guidewire with an uncoated tip was advanced into the right ventricle through the guiding sheath, and unipolar capture threshold, R-wave sensing amplitude, and pacing impedance were measured.
  
  
  RESULTS
  RV pacing was successful in all patients. The mean capture threshold was 3.8 +/- 2.1 V/0.5 ms, R-wave amplitude 5.4 +/- 4.3 mV, and pacing impedance 226 +/- 78 Omega. No arrhythmia was observed during the tests. Two patients developed complete heart block during the implant procedure and were successfully paced temporarily using the 0.035'' guidewire.
  
  
  CONCLUSIONS
  Temporary RV pacing, using a 0.035'' guidewire within the guiding sheath, is a simple, reliable, and safe method that allows backup pacing in case of traumatic complete heart block, developing during the implantation of biventricular devices.
authors.affiliation: Cardiology Service, University Hospital of Geneva, Geneva, Switzerland. haran.burri@hcuge.ch
authors.forename: Haran
authors.initials: H
authors.lastname: Burri
authors.forename: Henri
authors.initials: H
authors.lastname: Sunthorn
authors.forename: Marc
authors.initials: M
authors.lastname: Zimmermann
authors.forename: Carine
authors.initials: C
authors.lastname: Stettler
authors.forename: Dipen
authors.initials: D
authors.lastname: Shah
mesh_terms: D000368:Aged; D004567:Electrodes, Implanted / Q000009:adverse effects*; D005260:Female; D006327:Heart Block / Q000209:etiology / Q000517:prevention & control*; D006352:Heart Ventricles / Q000601:surgery*; D006801:Humans; D008297:Male; D010138:Pacemaker, Artificial / Q000009:adverse effects*; D019919:Prosthesis Implantation / Q000009:adverse effects* / Q000295:instrumentation*; D016896:Treatment Outcome