title: Surveillance of AF recurrence post-surgical AF ablation using implantable cardiac monitor.
abstract: BACKGROUND
  Although pulmonary vein isolation is an effective treatment for recurrent atrial fibrillation (AF), there is no consensus on the definition of success or follow-up strategies. Existing data are limited to intermittent Holter or transtelephonic monitoring with reliance on patient symptoms.
  
  
  OBJECTIVE
  We sought to determine the outcomes of surgical ablation and post-ablation AF surveillance with a leadless implantable cardiac monitor (ICM).
  
  
  METHODS
  Forty-five patients with drug-refractory paroxysmal or persistent AF underwent video-assisted epicardial ablation using a bipolar radiofrequency clamp. An ICM was implanted subcutaneously post-ablation to assess AF recurrence. AF recurrence was defined as ≥1 AF episode with a duration of ≥30 s. The device-stored data was downloaded weekly over the internet, and all transmitted events were reviewed.
  
  
  RESULTS
  A total of 1,220 AF automatic and patient-activated AF episodes were analyzed over a follow-up of 12 ± 3 months. Of these episodes, 46% were asymptomatic. Furthermore, only 66% of the patient-activated episodes were AF. AF recurrence was highest in first 4 weeks and substantially decreased 6 months post-ablation. The overall freedom from AF recurrence at the end of follow-up was 60%. When 48-h Holter recordings were compared with the device-stored episodes, the sensitivity of the device to detect AF was 98%, and the specificity was 71%.
  
  
  CONCLUSIONS
  The ICM provides an objective measure of AF ablation success and may be useful in making clinical decisions. This device may be used in future ablation studies to develop a more rigorous definition of procedural success.
authors.affiliation: Thoracic and Cardiovascular Healthcare Foundation, Lansing, MI 48910, USA. jip@tciheart.com
authors.forename: John H
authors.initials: JH
authors.lastname: Ip
authors.forename: Maria
authors.initials: M
authors.lastname: Viqar-Syed
authors.forename: Denise
authors.initials: D
authors.lastname: Grimes
authors.forename: Yan
authors.initials: Y
authors.lastname: Xie
authors.forename: Kevin
authors.initials: K
authors.lastname: Jager
authors.forename: Jennifer
authors.initials: J
authors.lastname: Boak
authors.forename: Divyakant
authors.initials: D
authors.lastname: Gandhi
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery*; D017115:Catheter Ablation; D015716:Electrocardiography, Ambulatory; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019736:Prostheses and Implants; D012008:Recurrence