title: N-3 polyunsaturated fatty acid supplementation does not reduce vulnerability to atrial fibrillation in remodeling atria.
abstract: BACKGROUND
  Prophylactic supplementation with omega-3 polyunsaturated fatty acids (PUFAs) reduce vulnerability to atrial fibrillation (AF). The effect of PUFAs given after cardiac injury has occurred is unknown.
  
  
  OBJECTIVE
  To investigate using a model of pacing-induced cardiac injury, the time course of development of injury and whether it was altered by postinjury PUFAs.
  
  
  METHODS
  Sixty-five dogs were randomized to undergo simultaneous atrial and ventricular pacing (SAVP, 220 beats/min) for 0, 2, 7, or 14 days. Twenty-two dogs received PUFAs (850 mg/d) either prophylactically or after some pacing had occurred (postinjury). Electrophysiologic and echocardiographic measurements were taken at baseline and sacrifice. Atrial tissue samples were collected at sacrifice for histologic and molecular analyses.
  
  
  RESULTS
  With no PUFAs, the inducibility of AF increased with pacing duration (P < .001). Postinjury PUFAs (started after 7 days of pacing) did not reduce the inducibility of AF after 14 days of pacing (9.3% ± 8.8% no PUFAs vs 9.7% ± 9.9% postinjury PUFAs; P = .91). Atrial myocyte size and fibrosis increased with pacing duration (P < .05). Postinjury PUFAs did not significantly attenuate the cell size increase after 14 days of pacing (no PUFAs 38% ± 30% vs postinjury PUFAs 19% ± 28%; P = .11). Similarly, postinjury PUFAs did not attenuate the increase in fibrosis after 14 days of pacing (no PUFAs 66% ± 51% vs postinjury PUFAs 63% ± 76%; P = .90).
  
  
  CONCLUSIONS
  PUFA supplementation begun after cardiac injury has already occurred does not reduce atrial structural remodeling or vulnerability to AF.
authors.affiliation: Keenan Research Centre, Li Ka Shing Knowledge Institute, St Michael's Hospital, Toronto, Ontario, Canada.
authors.forename: Andrew
authors.initials: A
authors.lastname: Ramadeen
authors.forename: Kim A
authors.initials: KA
authors.lastname: Connelly
authors.forename: Howard
authors.initials: H
authors.lastname: Leong-Poi
authors.forename: Xudong
authors.initials: X
authors.lastname: Hu
authors.forename: Hiroko
authors.initials: H
authors.lastname: Fujii
authors.forename: Richard
authors.initials: R
authors.lastname: Van Krieken
authors.forename: Gabriel
authors.initials: G
authors.lastname: Laurent
authors.forename: Bruce J
authors.initials: BJ
authors.lastname: Holub
authors.forename: Richard P
authors.initials: RP
authors.lastname: Bazinet
authors.forename: Paul
authors.initials: P
authors.lastname: Dorian
mesh_terms: D000818:Animals; D001281:Atrial Fibrillation / Q000517:prevention & control*; D016275:Atrial Function / Q000187:drug effects; D002304:Cardiac Pacing, Artificial / Q000009:adverse effects; D019587:Dietary Supplements; D004195:Disease Models, Animal; D004285:Dogs; D022062:Electrophysiologic Techniques, Cardiac; D015525:Fatty Acids, Omega-3 / Q000008:administration & dosage*; D005260:Female; D006329:Heart Conduction System / Q000503:physiopathology; D006335:Heart Injuries / Q000150:complications / Q000503:physiopathology*; D006984:Hypertrophy; D032383:Myocytes, Cardiac / Q000473:pathology; D060888:Real-Time Polymerase Chain Reaction
chemical_list: D015525:Fatty Acids, Omega-3