title: Ablation of multi-wavelet re-entry: general principles and in silico analyses.
abstract: OBJECTIVE
  Catheter ablation strategies for treatment of cardiac arrhythmias are quite successful when targeting spatially constrained substrates. Complex, dynamic, and spatially varying substrates, however, pose a significant challenge for ablation, which delivers spatially fixed lesions. We describe tissue excitation using concepts of surface topology which provides a framework for addressing this challenge. The aim of this study was to test the efficacy of mechanism-based ablation strategies in the setting of complex dynamic substrates.
  
  
  RESULTS
  We used a computational model of propagation through electrically excitable tissue to test the effects of ablation on excitation patterns of progressively greater complexity, from fixed rotors to multi-wavelet re-entry. Our results indicate that (i) focal ablation at a spiral-wave core does not result in termination; (ii) termination requires linear lesions from the tissue edge to the spiral-wave core; (iii) meandering spiral-waves terminate upon collision with a boundary (linear lesion or tissue edge); (iv) the probability of terminating multi-wavelet re-entry is proportional to the ratio of total boundary length to tissue area; (v) the efficacy of linear lesions varies directly with the regional density of spiral-waves.
  
  
  CONCLUSIONS
  We establish a theoretical framework for re-entrant arrhythmias that explains the requirements for their successful treatment. We demonstrate the inadequacy of focal ablation for spatially fixed spiral-waves. Mechanistically guided principles for ablating multi-wavelet re-entry are provided. The potential to capitalize upon regional heterogeneity of spiral-wave density for improved ablation efficacy is described.
authors.affiliation: Department of Medicine, University of Vermont College of Burlington, VT 05401, USA. peter.spector@uvm.edu
authors.forename: Peter S
authors.initials: PS
authors.lastname: Spector
authors.forename: Daniel D
authors.initials: DD
authors.lastname: Correa de Sa
authors.forename: Ethan S
authors.initials: ES
authors.lastname: Tischler
authors.forename: Nathaniel C
authors.initials: NC
authors.lastname: Thompson
authors.forename: Nicole
authors.initials: N
authors.lastname: Habel
authors.forename: Justin
authors.initials: J
authors.lastname: Stinnett-Donnelly
authors.forename: Bryce E
authors.initials: BE
authors.lastname: Benson
authors.forename: Philipp
authors.initials: P
authors.lastname: Bielau
authors.forename: Jason H T
authors.initials: JH
authors.lastname: Bates
mesh_terms: D000200:Action Potentials; D000818:Animals; D003198:Computer Simulation; D006329:Heart Conduction System / Q000503:physiopathology* / Q000601:surgery*; D006801:Humans; D008955:Models, Cardiovascular; D025321:Surgery, Computer-Assisted / Q000379:methods*; D054139:Tachycardia, Reciprocating / Q000503:physiopathology* / Q000601:surgery*; D016896:Treatment Outcome