title: Myocardial lesion depth with circular electroporation ablation.
abstract: BACKGROUND
  Recently, we demonstrated the feasibility and safety of circular electroporation ablation in porcine pulmonary vein ostia, but the relationship between the magnitude of the application and lesion dimensions is still unknown.
  
  
  RESULTS
  An in vivo porcine study was performed on left ventricular epicardium submerged under 10 mm of blood, using devices that mimic a 20-mm-diameter 7F circular ablation catheter. Model D contained 10 separate electrodes, whereas model M consisted of 1 circular electrode. Ablations were performed at 50, 100, and 200 J with model D and at 100 J with model M. Lesion dimensions were measured after 3-week survival. All applications resulted in smooth voltage waveforms demonstrating the absence of vapor globe formation, arcing, and a pressure wave. Applications up to 100 J with model D resulted in separate lesions under the electrodes. At 200 J, continuous deep circular lesions were created despite the use of separate electrodes. There was a significant relationship between applied current and median lesion depth, with a slope of 0.17 mm/A. At 100 J, there was no difference in lesion depth or width between models D and M. The electrodes and ablation site directly after ablation showed no signs of thermal damage.
  
  
  CONCLUSIONS
  In an epicardial porcine model with blood around the application site, continuous circular lesions, deep enough for electric pulmonary vein isolation, were created with a single circular 200-J application. Lesions were continuous despite the use of separate electrodes. Lesion depth increased with the magnitude of the application.
authors.affiliation: Division of Heart and Lungs, the Department of Cardiology, University Medical Center Utrecht, Utrecht, the Netherlands. fredwittkampf@gmail.com
authors.forename: Fred H M
authors.initials: FH
authors.lastname: Wittkampf
authors.forename: Vincent J
authors.initials: VJ
authors.lastname: van Driel
authors.forename: Harry
authors.initials: H
authors.lastname: van Wessel
authors.forename: Kars G E J
authors.initials: KG
authors.lastname: Neven
authors.forename: Paul F
authors.initials: PF
authors.lastname: Gründeman
authors.forename: Aryan
authors.initials: A
authors.lastname: Vink
authors.forename: Peter
authors.initials: P
authors.lastname: Loh
authors.forename: Pieter A
authors.initials: PA
authors.lastname: Doevendans
mesh_terms: D000818:Animals; D017115:Catheter Ablation / Q000379:methods*; D004195:Disease Models, Animal; D018274:Electroporation; D006352:Heart Ventricles / Q000473:pathology / Q000601:surgery*; D009206:Myocardium / Q000473:pathology*; D010496:Pericardium / Q000473:pathology / Q000601:surgery*; D013552:Swine; D017180:Tachycardia, Ventricular / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*