title: Spinal cord stimulation protects against atrial fibrillation induced by tachypacing.
abstract: BACKGROUND
  Spinal cord stimulation (SCS) has been shown to modulate atrial electrophysiology and confer protection against ischemia and ventricular arrhythmias in animal models.
  
  
  OBJECTIVE
  To determine whether SCS reduces the susceptibility to atrial fibrillation (AF) induced by tachypacing (TP).
  
  
  METHODS
  In 21 canines, upper thoracic SCS systems and custom cardiac pacing systems were implanted. Right atrial and left atrial effective refractory periods were measured at baseline and after 15 minutes of SCS. Following recovery in a subset of canines, pacemakers were turned on to induce AF by alternately delivering TP and searching for AF. Canines were randomized to no SCS therapy (CTL) or intermittent SCS therapy on the initiation of TP (EARLY) or after 8 weeks of TP (LATE). AF burden (percent AF relative to total sense time) and AF inducibility (percentage of TP periods resulting in AF) were monitored weekly. After 15 weeks, echocardiography and histology were performed.
  
  
  RESULTS
  Effective refractory periods increased by 21 ± 14 ms (P = .001) in the left atrium and 29 ± 12 ms (P = .002) in the right atrium after acute SCS. AF burden was reduced for 11 weeks in EARLY compared with CTL (P <.05) animals. AF inducibility remained lower by week 15 in EARLY compared with CTL animals (32% ± 10% vs 91% ± 6%; P <.05). AF burden and inducibility were not significantly different between LATE and CTL animals. There were no structural differences among any groups.
  
  
  CONCLUSIONS
  SCS prolonged atrial effective refractory periods and reduced AF burden and inducibility in a canine AF model induced by TP. These data suggest that SCS may represent a treatment option for AF.
authors.affiliation: Division of Cardiology, Department of Medicine, New York University School of Medicine, New York, New York 10016, USA.
authors.forename: Scott A
authors.initials: SA
authors.lastname: Bernstein
authors.forename: Brian
authors.initials: B
authors.lastname: Wong
authors.forename: Carolina
authors.initials: C
authors.lastname: Vasquez
authors.forename: Stuart P
authors.initials: SP
authors.lastname: Rosenberg
authors.forename: Ryan
authors.initials: R
authors.lastname: Rooke
authors.forename: Laura M
authors.initials: LM
authors.lastname: Kuznekoff
authors.forename: Joshua M
authors.initials: JM
authors.lastname: Lader
authors.forename: Vanessa M
authors.initials: VM
authors.lastname: Mahoney
authors.forename: Tatyana
authors.initials: T
authors.lastname: Budylin
authors.forename: Marie
authors.initials: M
authors.lastname: Älvstrand
authors.forename: Tammy
authors.initials: T
authors.lastname: Rakowski-Anderson
authors.forename: Rupinder
authors.initials: R
authors.lastname: Bharmi
authors.forename: Riddhi
authors.initials: R
authors.lastname: Shah
authors.forename: Steven
authors.initials: S
authors.lastname: Fowler
authors.forename: Douglas
authors.initials: D
authors.lastname: Holmes
authors.forename: Taraneh G
authors.initials: TG
authors.lastname: Farazi
authors.forename: Larry A
authors.initials: LA
authors.lastname: Chinitz
authors.forename: Gregory E
authors.initials: GE
authors.lastname: Morley
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001281:Atrial Fibrillation / Q000209:etiology / Q000473:pathology / Q000517:prevention & control*; D002304:Cardiac Pacing, Artificial / Q000009:adverse effects*; D004195:Disease Models, Animal; D004285:Dogs; D004562:Electrocardiography; D006325:Heart Atria / Q000294:innervation; D018570:Risk Assessment; D013116:Spinal Cord / Q000502:physiology; D062187:Spinal Cord Stimulation / Q000379:methods*; D013997:Time Factors