title: Spontaneous episodes of atrial fibrillation after implantation of the Metrix Atrioverter: observations on treated and nontreated episodes. Metrix Investigators.
abstract: OBJECTIVE
  We sought to evaluate the number and duration of device-treated and self-terminating, nontreated episodes of atrial fibrillation (AF) after implantation of the Metrix Atrioverter.
  
  
  BACKGROUND
  A recent study has shown that the Atrioverter can rapidly restore sinus rhythm in patients with AF; however, the effect of the device on the clinical course of the arrhythmia in these patients is unknown.
  
  
  METHODS
  The Atrioverter was implanted in 51 patients with symptomatic, recurrent, drug-refractory AF. The device was programmed to periodically monitor the cardiac rhythm. Defibrillation of AF episodes was performed under physician observation.
  
  
  RESULTS
  During a mean follow-up of 260 +/- 144 days, 1,161 episodes of AF were observed during valid monitoring periods in 45 of 51 patients. Forty-one patients experienced 231 episodes for which they sought defibrillation therapy. The average duration of the treated episodes during valid monitoring periods (190 of 231 episodes in 39 of 41 patients) was significantly longer than that of the nontreated episodes (38 +/- 44 vs. 10 +/- 8 h; p < 0.05). The time between episodes requiring Atrioverter therapy increased, and the risk of having an episode requiring treatment decreased. No changes were observed in the number and duration of the short-lasting, nontreated episodes as time since implantation of the device increased.
  
  
  CONCLUSIONS
  In patients with symptomatic, recurrent, drug-refractory AF, the frequency of long-lasting episodes, which were treated under observation with repeated defibrillation using the Atrioverter, decreased. The number and duration of short-lasting, nontreated episodes did not change during the 20-month study period. The effect of ambulatory use of the device on the recurrence of short-lasting episodes needs to be evaluated.
authors.affiliation: Department of Cardiology, Academic Hospital, Maastricht, The Netherlands. C.Timmermans@cardio.azm.nl
authors.forename: C
authors.initials: C
authors.lastname: Timmermans
authors.forename: S
authors.initials: S
authors.lastname: Lévy
authors.forename: G M
authors.initials: GM
authors.lastname: Ayers
authors.forename: W
authors.initials: W
authors.lastname: Jung
authors.forename: L
authors.initials: L
authors.lastname: Jordaens
authors.forename: M
authors.initials: M
authors.lastname: Rosenqvist
authors.forename: B
authors.initials: B
authors.lastname: Thibault
authors.forename: J
authors.initials: J
authors.lastname: Camm
authors.forename: L M
authors.initials: LM
authors.lastname: Rodriguez
authors.forename: H J
authors.initials: HJ
authors.lastname: Wellens
mesh_terms: D000328:Adult; D000368:Aged; D001281:Atrial Fibrillation / Q000209:etiology / Q000628:therapy*; D017147:Defibrillators, Implantable; D015716:Electrocardiography, Ambulatory; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011474:Prosthesis Design; D012008:Recurrence