title: Visualizing ablation gaps in vitro using a deflectable fiber optic endocardial visualization catheter.
abstract: BACKGROUND
  The efficacy of pulmonary vein isolation for the treatment of atrial fibrillation may be limited by the ability to make continuous and transmural lesions utilizing an ablation catheter. Gaps often persist between ablation lesions leading to failed electrical isolation and thus failed ablation. Recently, a deflectable fiberoptic endocardial visualization catheter has been introduced for use in imaging the coronary sinus using light in the visible spectrum. We utilize this catheter to visualize the endocardial surface and examine radiofrequency ablation lesions in porcine endocardium to determine the presence of gaps between radiofrequency lesions.
  
  
  METHODS
  Videos were taken of the lesions and shown to two readers who were asked to identify the gaps ranging from less than 0.1 mm-9.8 mm.
  
  
  RESULTS
  Ninety-four lesion gaps were reviewed. The readers demonstrated a combined accuracy of 98.4% at identifying gaps.
  
  
  CONCLUSIONS
  Gaps between ablation lesions can be accurately identified down to less than 1 mm distances in vitro using a direct visualization catheter. Further studies are warranted to confirm these finding in vivo.
authors.affiliation: Stanford University School of Medicine, Stanford, USA.
authors.forename: Afraaz R
authors.initials: AR
authors.lastname: Irani
authors.forename: Bryant
authors.initials: B
authors.lastname: Lin
authors.forename: Christian
authors.initials: C
authors.lastname: Eversull
authors.forename: Henry H
authors.initials: HH
authors.lastname: Hsia
authors.forename: Paul C
authors.initials: PC
authors.lastname: Zei
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Wang
authors.forename: Amin
authors.initials: A
authors.lastname: Al-Ahmad
mesh_terms: D000818:Animals; D006328:Cardiac Catheterization / Q000295:instrumentation*; D017115:Catheter Ablation / Q000295:instrumentation* / Q000379:methods; D004699:Endocardium / Q000033:anatomy & histology* / Q000601:surgery*; D019723:Endoscopes; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005336:Fiber Optic Technology / Q000295:instrumentation*; D066298:In Vitro Techniques; D025321:Surgery, Computer-Assisted / Q000295:instrumentation*; D013552:Swine