title: Recurrence of atrial tachyarrhythmias in implantable cardioverter-defibrillator recipients.
abstract: BACKGROUND
  Because the natural history of atrial tachyarrhythmia (AT) is not known in patients with implantable cardioverter-defibrillators (ICDs) but without device-based atrial therapies, we aimed to describe the characteristics and recurrence of AT in such patients.
  
  
  METHODS
  In this multicenter trial, 269 patients with standard indications for ICD placement and 2 episodes of AT in the preceding year received a dual-chamber ICD capable of logging AT. Patients were randomly assigned to 3-month periods of atrial therapies "on" or "off." This analysis considered only the 118 patients with atrial therapies programmed off at ICD placement.
  
  
  RESULTS
  Fifty-eight patients (49%) had at least 1 AT episode longer than 1 minute, and 21 (18%) had at least 1 prolonged episode (>24 hours). The median episode frequency for each patient (episodes per month) was 1.8 episodes longer than 1 minute, 0.8 longer than 1 hour, and 0 longer than 24 hours. The median AT burden was 12.2 hours per month.
  
  
  CONCLUSIONS
  Patients with standard ICD indications and history of AT have infrequent episodes, frequent short episodes, or prolonged episodes of AT-atrial fibrillation. However, the clinical characteristics examined did not distinguish among the groups. Improved diagnostic tools may help identify patients at risk for development of AT, thereby allowing specific therapies to be targeted to each group of patients.
authors.affiliation: Division of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota 55905, USA.
authors.forename: Dawood
authors.initials: D
authors.lastname: Darbar
authors.forename: Eduardo N
authors.initials: EN
authors.lastname: Warman
authors.forename: Stephen C
authors.initials: SC
authors.lastname: Hammill
authors.forename: Paul A
authors.initials: PA
authors.lastname: Friedman
mesh_terms: D000368:Aged; D017147:Defibrillators, Implantable; D005260:Female; D006325:Heart Atria; D006801:Humans; D008297:Male; D012008:Recurrence; D013610:Tachycardia / Q000453:epidemiology* / Q000628:therapy*