title: Implantable intravascular defibrillator: defibrillation thresholds of an intravascular cardioverter-defibrillator compared with those of a conventional ICD in humans.
abstract: BACKGROUND
  A percutaneous intravascular cardioverter-defibrillator (PICD) has been developed with a right ventricular (RV) single-coil lead and titanium electrodes in the superior vena cava (SVC)-brachiocephalic vein (BCV) region and the inferior vena cava (IVC).
  
  
  OBJECTIVE
  To compare defibrillation thresholds (DFTs) of the PICD with those of a conventional ICD in humans.
  
  
  METHODS
  Ten patients with ischemic cardiomyopathy and ejection fraction ≤35% were randomized to initial testing with either PICD or conventional ICD. A standard dual-coil lead was positioned in the RV apex. If randomized to PICD, the device was placed into the vasculature such that 1 titanium electrode was positioned in the SVC-BCV region and the second in the IVC. For PICD DFTs, the RV coil of the conventional ICD lead was connected to the PICD mandrel [shock vector: RV (+) to SVC-BCV (-) + IVC (-)]. When testing the conventional ICD, a subcutaneous pocket was formed in the left pectoralis region and the ICD was connected to the lead system and positioned in the pocket [shock vector: RV (+) to SVC (-) + active can (-)]. Each device was removed before testing with the other. A step-down binary search protocol determined the DFT, with the initial shock being 9 J.
  
  
  RESULTS
  The mean PICD DFT was 7.6 ± 3.3 J, and the conventional ICD system demonstrated a mean DFT of 9.5 ± 4.7 J (N = 10; paired t test, P = .28).
  
  
  CONCLUSIONS
  The intravascular defibrillator has DFTs similar to those of commercially available ICDs.
authors.affiliation: Hospital Na Homolce, Prague, Czech Republic.
authors.forename: Petr
authors.initials: P
authors.lastname: Neuzil
authors.affiliation: Mount Sinai School of Medicine, New York, New York.
authors.forename: Vivek Y
authors.initials: VY
authors.lastname: Reddy
authors.affiliation: Heart Center Semmelweis University, Budapest, Hungary.
authors.forename: Bela
authors.initials: B
authors.lastname: Merkely
authors.affiliation: Heart Center Semmelweis University, Budapest, Hungary.
authors.forename: Laszlo
authors.initials: L
authors.lastname: Geller
authors.affiliation: Heart Center Semmelweis University, Budapest, Hungary.
authors.forename: Levente
authors.initials: L
authors.lastname: Molnar
authors.affiliation: John Paul II Hospital, Jagiellonian University, Krakow, Poland.
authors.forename: Jacek
authors.initials: J
authors.lastname: Bednarek
authors.affiliation: John Paul II Hospital, Jagiellonian University, Krakow, Poland.
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Bartus
authors.affiliation: InnerPulse, Research Triangle Park, North Carolina.
authors.forename: Mark
authors.initials: M
authors.lastname: Richey
authors.affiliation: InnerPulse, Research Triangle Park, North Carolina.
authors.forename: T J Ransbury
authors.initials: TJ
authors.lastname: Bsee
authors.affiliation: University of North Carolina, Chapel Hill, North Carolina. Electronic address: wesanders@me.com.
authors.forename: William E
authors.initials: WE
authors.lastname: Sanders
mesh_terms: D000368:Aged; D009202:Cardiomyopathies / Q000628:therapy; D017147:Defibrillators, Implantable; D004867:Equipment Design; D005260:Female; D006352:Heart Ventricles; D006801:Humans; D008297:Male; D008875:Middle Aged; D013318:Stroke Volume
keywords: BCV; DFT; Defibrillation threshold; ICD; IVC; Implantable cardioverter-defibrillator; Intravascular defibrillator; PICD; RV; SVC; VF; brachiocephalic vein; defibrillation threshold; implantable cardioverter-defibrillator; inferior vena cava; percutaneous intravascular cardioverter-defibrillator; right ventricle/ventricular; superior vena cava; ventricular fibrillation