title: Clinical experience with tiered atrial therapies and atrial arrhythmia prevention algorithms in a dual chamber cardioverter defibrillator.
abstract: BACKGROUND
  The acceptance of atrial arrhythmia features in implantable cardioverter defibrillators (ICDs) will depend on their ability to appropriately discriminate atrial tachyarrhythmias/atrial fibrillation (AT/AF). This study tested the effectiveness of an atrial/ventricular ICD with advanced atrial detection and new algorithms designed to prevent atrial arrhythmias.
  
  
  RESULTS
  Ninety-five patients were implanted with a dual chamber ICD (Model 1900, Guidant Corporation, MN, USA) at 25 US centers. Ten patients received a coronary sinus (CS) lead allowing a defibrillation vector for AT/AF cardioversion. Follow-up was 12.2 months. The addition of new atrial features designed for detection, discrimination, and prevention of AT/AF had no adverse effect upon detection of induced ventricular fibrillation (VF) (mean detection time with new features ON was 2.22 seconds vs 2.19 seconds with features OFF). A total of 100% of the induced and spontaneous ventricular and atrial arrhythmias receiving shock therapy were reviewed as appropriate detection. Atrial shock conversion efficacy for spontaneous and induced AT/AF episodes was 83% and 96%, respectively (144 spontaneous, 162 induced episodes). A 3-month randomized crossover trial of atrial preventative pacing features did not result in adverse effects, but there was no clinical efficacy for prevention of AT/AF.
  
  
  CONCLUSIONS
  Enhanced atrial detection and discrimination features combined with tiered atrial therapies did not adversely impact the ability of the ICD (Model 1900) to appropriately detect and treat ventricular tachyarrhythmias.
authors.affiliation: Riverside Methodist Hospital, Columbus, OH, USA. edaoud@pol.net
authors.forename: Emile G
authors.initials: EG
authors.lastname: Daoud
authors.forename: Koonlawee
authors.initials: K
authors.lastname: Nademanee
authors.forename: Charles
authors.initials: C
authors.lastname: Fuenzalida
authors.forename: Gery F
authors.initials: GF
authors.lastname: Tomassoni
authors.forename: Claudio
authors.initials: C
authors.lastname: Schuger
authors.forename: Michael
authors.initials: M
authors.lastname: Chisner
authors.forename: Melissa
authors.initials: M
authors.lastname: Simones
authors.forename: Mark
authors.initials: M
authors.lastname: Schwartz
authors.forename: Helen
authors.initials: H
authors.lastname: Reeve
mesh_terms: D000368:Aged; D000465:Algorithms; D001281:Atrial Fibrillation / Q000503:physiopathology / Q000517:prevention & control*; D002304:Cardiac Pacing, Artificial; D018592:Cross-Over Studies; D017147:Defibrillators, Implantable / Q000009:adverse effects; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017180:Tachycardia, Ventricular / Q000628:therapy