title: Performance of dedicated versus integrated bipolar defibrillator leads with CRT-defibrillators: results from a Prospective Multicenter Study.
abstract: BACKGROUND
  Right ventricular (RV) anodal stimulation may occur in cardiac resynchronization therapy defibrillators (CRT-D) when left ventricular (LV) pacing is configured between the LV lead and an electrode on the RV defibrillator lead. RV defibrillator leads can have a dedicated proximal pacing ring electrode (dedicated bipolar) or utilize the distal shocking coil as the proximal pacing electrode (integrated bipolar). This study compares the performance of integrated versus dedicated leads with respect to anodal stimulation incidence, sensing, and inappropriate ventricular tachyarrhythmia detection in patients implanted with CRT-D.
  
  
  METHODS
  Two hundred ninety-two patients were randomly assigned to receive dedicated or integrated bipolar RV leads at the time of CRT-D implantation. Patients were followed for 6 months.
  
  
  RESULTS
  Patients with dedicated bipolar RV leads exhibited markedly higher rates of anodal stimulation than did patients with integrated leads. The incidence of anodal stimulation was 64% at implant for dedicated bipolar RV leads compared to 1% for integrated bipolar RV leads. The likelihood of anodal stimulation in patients with dedicated leads fell progressively during the 6-month follow-up (51.5%), but always exceeded the incidence of anodal stimulation in patients with integrated leads (5%). Clinically detectable undersensing and oversensing were very unusual and did not differ significantly between lead designs. There were no inappropriate ventricular tachyarrhythmia detections for either lead type.
  
  
  CONCLUSIONS
  Integrated bipolar RV defibrillator leads had a significantly lower incidence of RV anodal stimulation when compared to dedicated bipolar RV defibrillation leads, with no clinically detectable oversensing or undersensing, and with no inappropriate ventricular tachyarrhythmia detections for either lead type.
authors.affiliation: University of Utah Hospitals and Clinics, Salt Lake City, Utah 84132, USA. roger.freedman@hsc.utah.edu
authors.forename: Roger A
authors.initials: RA
authors.lastname: Freedman
authors.forename: Alex
authors.initials: A
authors.lastname: Petrakian
authors.forename: Ker
authors.initials: K
authors.lastname: Boyce
authors.forename: Charles
authors.initials: C
authors.lastname: Haffajee
authors.forename: Jesus E
authors.initials: JE
authors.lastname: Val-Mejias
authors.forename: Ashish L
authors.initials: AL
authors.lastname: Oza
mesh_terms: D000368:Aged; D017147:Defibrillators, Implantable / Q000706:statistics & numerical data*; D004567:Electrodes, Implanted / Q000145:classification / Q000706:statistics & numerical data*; D004867:Equipment Design; D004868:Equipment Failure / Q000706:statistics & numerical data*; D019544:Equipment Failure Analysis; D006801:Humans; D015994:Incidence; D017180:Tachycardia, Ventricular / Q000453:epidemiology* / Q000517:prevention & control*; D016896:Treatment Outcome; D014481:United States / Q000453:epidemiology