title: Use of a biophysical model of atrial fibrillation in the interpretation of the outcome of surgical ablation procedures.
abstract: OBJECTIVE
  To determine the adequacy of 'in silico' biophysical models of atrial fibrillation (AF) in the design of different ablation line patterns.
  
  
  BACKGROUND
  Permanent AF is a severe medical problem for which (surgical) ablation is a possible treatment. The ideal ablation pattern remains to be defined.
  
  
  METHODS
  Forty-six consecutive adult patients with symptomatic permanent drug refractory AF underwent mitral surgery combined with non-transmural, (n=20) and transmural (n=26) radiofrequency Minimaze. The fraction of 'in vivo' conversions to sinus rhythm (SR) in both groups was compared with the performance of the fraction of 'in silico' conversions observed in a biophysical model of permanent AF. The simulations allowed us to study the effectiveness of incomplete and complete ablation patterns. A simulated, complete, transmural Maze III ablation pattern was applied to 118 different episodes of simulated AF set-up in the model and its effectiveness was compared with the clinical results reported by Cox.
  
  
  RESULTS
  The fraction of conversions to SR was 92% 'in vivo' and 88% 'in silico' (p=ns) for transmural/complete ablations, 60% respectively 65% for non-transmural/incomplete Minimaze (p=ns) and 98% respectively 100% for Maze III ablations (p=ns). The fraction of conversions to SR 'in silico' correlated with the rates 'in vivo' (r2=0.973).
  
  
  CONCLUSIONS
  The fraction of conversions to SR observed in the model closely corresponded to the conversion rate to SR post-surgery. This suggests that the model provides an additional, non-invasive tool for optimizing ablation line patterns for treating permanent AF.
authors.affiliation: Department of Cardiovascular Surgery, University Hospital, Lausanne, Switzerland. Patrick.Ruchat@chuv.hospvd.ch
authors.forename: Patrick
authors.initials: P
authors.lastname: Ruchat
authors.forename: Lam
authors.initials: L
authors.lastname: Dang
authors.forename: Jürg
authors.initials: J
authors.lastname: Schlaepfer
authors.forename: Nathalie
authors.initials: N
authors.lastname: Virag
authors.forename: Ludwig Karl
authors.initials: LK
authors.lastname: von Segesser
authors.forename: Lukas
authors.initials: L
authors.lastname: Kappenberger
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000473:pathology / Q000601:surgery*; D017115:Catheter Ablation / Q000379:methods*; D005260:Female; D006325:Heart Atria / Q000473:pathology / Q000601:surgery; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D008955:Models, Cardiovascular; D016896:Treatment Outcome