title: Indications for dual-chamber cardioverter defibrillators at implant and at 1 year follow-up: a retrospective analysis in the single-chamber defibrillator era.
abstract: OBJECTIVE
  This retrospective four-centre study assessed the current indications for dual-chamber implantable cardioverter defibrillators (ICDs) at implant and during a medium-term follow-up period in a group of patients treated by single-chamber ICD in the pre dual-chamber ICD era.
  
  
  RESULTS
  The study population consisted of 153 consecutive patients (127 males, mean age 58 +/- 6 years) treated by single-chamber ICD for ventricular tachycardia and/or ventricular fibrillation. Definite indications for having a dual-chamber ICD included the presence of sinus node dysfunction and of second- or third-degree atrioventricular (AV) block, while possible indications were represented by paroxysmal atrial fibrillation or flutter and first-degree AV block. At implant, dual-chamber ICD would appear definitely indicated in 10.5% of cases, and possibly indicated in an additional 17.5% of cases. During 12 +/- 10 months follow-up, such percentages remained stable (11 and 19.5%, respectively). Inappropriate ICD intervention was documented in five of 13 patients (38%), with episodes of paroxysmal atrial fibrillation or flutter.
  
  
  CONCLUSIONS
  In this non-selected study population, a dual-chamber ICD would have potentially benefited approximately 30% of the patients. During medium-term follow-up, there was no progression towards increasing dual-chamber ICD indications. The 15% cumulative incidence of paroxysmal atrial tachyarrhythmias justifies the activation of dedicated detection algorithms.
authors.affiliation: Ospedale S Maria della Misericordia, Fondazione IRCAB, Udine, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Proclemer
authors.forename: P
authors.initials: P
authors.lastname: Della Bella
authors.forename: D
authors.initials: D
authors.lastname: Facchin
authors.forename: L
authors.initials: L
authors.lastname: Fattore
authors.forename: C
authors.initials: C
authors.lastname: Carbucicchio
authors.forename: C
authors.initials: C
authors.lastname: Tondo
authors.forename: M
authors.initials: M
authors.lastname: Lunati
authors.forename: M R
authors.initials: MR
authors.lastname: Vecchi
authors.forename: E
authors.initials: E
authors.lastname: Petz
authors.forename: M
authors.initials: M
authors.lastname: Zecchin
mesh_terms: D000328:Adult; D000368:Aged; D001281:Atrial Fibrillation / Q000628:therapy*; D017147:Defibrillators, Implantable; D004867:Equipment Design; D005260:Female; D005500:Follow-Up Studies; D006327:Heart Block / Q000628:therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D018579:Patient Selection; D012189:Retrospective Studies; D012804:Sick Sinus Syndrome / Q000628:therapy*; D017180:Tachycardia, Ventricular / Q000628:therapy*; D016896:Treatment Outcome; D014693:Ventricular Fibrillation / Q000628:therapy*