title: Ablation of multiwavelet re-entry guided by circuit-density and distribution: maximizing the probability of circuit annihilation.
abstract: BACKGROUND
  A key mechanism responsible for atrial fibrillation is multiwavelet re-entry (MWR). We have previously demonstrated improved efficiency of ablation when lesions were placed in regions of high circuit-density. In this study, we undertook a quantitative assessment of the relative effect of ablation on the probability of MWR termination and the inducibility of MWR, as a function of lesion length and circuit-density overlap.
  
  
  RESULTS
  We used a computational model to simulate MWR in tissues with (and without) localized regions of decreased action potential duration and increased intercellular resistance. We measured baseline circuit-density and distribution. We then assessed the effect of various ablation lesion sets on the inducibility and duration of MWR as a function of ablation lesion length and overlap with circuit-density. Higher circuit-density reproducibly localized to regions of shorter wavelength. Ablation lines with high circuit-density overlap showed maximum decreases in duration of MWR at lengths equal to the distance from the tissue boundary to the far side of the high circuit-density region (high-overlap, -43.5% [confidence interval, -22.0% to -65.1%] versus low-overlap, -4.4% [confidence interval, 7.3% to -16.0%]). Further ablation (beyond the length required to cross the high circuit-density region) provided minimal further reductions in duration and increased inducibility.
  
  
  CONCLUSIONS
  Ablation at sites of high circuit-density most efficiently decreased re-entrant duration while minimally increasing inducibility. Ablation lines delivered at sites of low circuit-density minimally decreased duration yet increased inducibility of MWR.
authors.affiliation: Department of Medicine, University of Vermont College of Medicine, Burlington, VT.
authors.forename: Richard T
authors.initials: RT
authors.lastname: Carrick
authors.forename: Bryce
authors.initials: B
authors.lastname: Benson
authors.forename: Nicole
authors.initials: N
authors.lastname: Habel
authors.forename: Oliver R J
authors.initials: OR
authors.lastname: Bates
authors.forename: Jason H T
authors.initials: JH
authors.lastname: Bates
authors.forename: Peter S
authors.initials: PS
authors.lastname: Spector
mesh_terms: D000200:Action Potentials / Q000502:physiology; D000465:Algorithms; D001281:Atrial Fibrillation / Q000503:physiopathology* / Q000601:surgery*; D017115:Catheter Ablation; D022062:Electrophysiologic Techniques, Cardiac; D006325:Heart Atria / Q000503:physiopathology; D006329:Heart Conduction System / Q000503:physiopathology*; D006801:Humans; D032383:Myocytes, Cardiac / Q000502:physiology; D016896:Treatment Outcome
keywords: arrhythmias, cardiac; atrial fibrillation; catheter ablation; electrophysiology