title: Worldwide evaluation of a defibrillation lead with a small geometric electrode surface for high-impedance pacing.
abstract: BACKGROUND
  Pacing leads with a small electrode surface for high-impedance stimulation have been shown to prolong pacemaker longevity, but no sufficient data is available on the safety and feasibility of a defibrillation lead with this novel design.
  
  
  METHODS
  We evaluated the clinical performance of a tined, steroid-eluting defibrillation lead with a small electrode surface area (model 6944) in a prospective multicenter study. A total of 542 patients with conventional indications for an implantable cardioverter defibrillator were randomized 1:1 to receive either the model 6944 or a tined, steroid-eluting defibrillation lead with a conventional sized electrode surface area (model 6942). Device performance and electrical parameters were evaluated at implant and 1, 3, 6, and 12 months thereafter (mean follow-up 11.3 +/- 5.6 months).
  
  
  RESULTS
  Baseline characteristics, lead implant success rates, and defibrillation thresholds did not differ significantly between the 2 groups. While pacing thresholds did not differ significantly during follow-up, pacing impedance was approximately twice as high in the model 6944 as in the model 6942 lead (P <.0001). Mean R-wave amplitudes were smaller in patients with a 6944 (9.1 +/- 3.1 mV vs 9.8 +/- 3.6 mV for model 6942, P <.05), but remained stable within both groups throughout the observation period. The total number of ventricular lead-related adverse events and patient survival did not differ significantly between the 2 groups.
  
  
  CONCLUSIONS
  The use of a defibrillation lead with a small electrode surface for high-efficiency pacing is safe and feasible and increases pacing impedance without significantly compromising clinical performance.
authors.affiliation: Herzzentrum, Georg-August-Universität, Göettingen, Germany. DirkVollmann2000@aol.com
authors.forename: Dirk
authors.initials: D
authors.lastname: Vollmann
authors.forename: Thomas
authors.initials: T
authors.lastname: Ahern
authors.forename: Bart
authors.initials: B
authors.lastname: Gerritse
authors.forename: Robert C
authors.initials: RC
authors.lastname: Canby
authors.forename: Dieter
authors.initials: D
authors.lastname: Zenker
authors.forename: Ludwig
authors.initials: L
authors.lastname: Binner
authors.forename: Shane K M
authors.initials: SK
authors.lastname: Kimber
authors.forename: Christina
authors.initials: C
authors.lastname: Unterberg
mesh_terms: D000368:Aged; D002170:Canada; D017147:Defibrillators, Implantable; D017097:Electric Impedance; D004567:Electrodes, Implanted; D004867:Equipment Design; D004868:Equipment Failure; D005060:Europe; D005260:Female; D006331:Heart Diseases / Q000628:therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D013997:Time Factors; D014481:United States