title: Nonthoracotomy implantation of cardioverter defibrillators: preliminary experience with a defibrillation lead placed at the right ventricular outflow tract.
abstract: Although morbidity and mortality associated with defibrillator implantation using a nonthoracotomy approach have decreased as compared with a thoracotomy approach, defibrillation thresholds have been higher and fewer patients satisfied implant criteria. It may be possible to improve on the success of nonthoracotomy defibrillator implantation by the placement of a right ventricular (RV) outflow defibrillation lead. Implantable cardioverter defibrillator implantation data of 30 consecutive patients with clinical VT or VF were reviewed. Three defibrillation leads were routinely used. When either pacing threshold at the RV apex was inadequate (n = 2) or 18-J shocks were not successful in terminating VF in 3 of 4 trials (n = 8), the RV apex lead was positioned to the RV outflow tract attaching to the septum. Defibrillation testing was first performed with the RV apex lead in combination with CS, SVC, and/or subcutaneous leads. Twenty patients satisfied implant criteria with a defibrillation threshold of 13.5 +/- 3.6 J. In 7 of the 10 patients, whose RV lead was repositioned to the RV outflow tract, this lead in combination with SVC, CS, or subcutaneous leads produced successful defibrillation at < or = 18 J or in 3 of 4 trials. This approach improved the overall success of nonthoracotomy implantation of defibrillators from 69% to 90%. After a follow-up of 27 +/- 6 months, there was no dislodgment of the RV outflow tract defibrillation leads.
  
  
  CONCLUSIONS
  This article reports the preliminary observation that placement of defibrillation leads to the RV outflow tract in humans was possible and without dislodgment. RV outflow tract offers an alternative for placement of defibrillation leads, which may improve on the success of nonthoracotomy defibrillator implantation.
authors.affiliation: Department of Medicine, University of Ottawa, Canada.
authors.forename: A S
authors.initials: AS
authors.lastname: Tang
authors.forename: P
authors.initials: P
authors.lastname: Hendry
authors.forename: W
authors.initials: W
authors.lastname: Goldstein
authors.forename: M S
authors.initials: MS
authors.lastname: Green
authors.forename: M
authors.initials: M
authors.lastname: Luce
mesh_terms: D000328:Adult; D000368:Aged; D017147:Defibrillators, Implantable; D005260:Female; D006352:Heart Ventricles; D006801:Humans; D008297:Male; D008722:Methods; D008875:Middle Aged; D013902:Radiography, Thoracic; D017180:Tachycardia, Ventricular / Q000628:therapy; D014693:Ventricular Fibrillation / Q000628:therapy