title: Modification of atrioventricular conduction in dogs by laser irradiation of Koch's triangle guided by balloon-tipped cardioscope.
abstract: OBJECTIVE
  This study assessed the feasibility of modification of atrioventricular (AV) conduction under direct vision with a new ablation system using laser energy.
  
  
  RESULTS
  In 23 anesthetized dogs, a combined laser and balloon-tipped endoscope was introduced into the right atrium after right thoracotomy. Koch's triangle was easily identified in all dogs endoscopically. Nd:YAG laser energy was delivered through an optical fiber positioned inside the saline-filled balloon to the middle portion of Koch's triangle in eight dogs (mid-Koch group) and to the posterior portion in 12 dogs (postero-Koch group). Complete AV block was achieved in five of eight dogs in the mid-Koch group. In the postero-Koch group, anterograde Wenckebach cycle length increased significantly from 178+/-23 ms to 202+/-37 ms (P = 0.008).
  
  
  CONCLUSIONS
  Selective laser ablation of Koch's triangle is feasible with a combined laser and balloon-tipped endoscope.
authors.affiliation: Department of Cardiovascular Medicine, Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: Kou
authors.initials: K
authors.lastname: Suzuki
authors.forename: Kenzo
authors.initials: K
authors.lastname: Hirao
authors.forename: Nobuo
authors.initials: N
authors.lastname: Toshida
authors.forename: Naohito
authors.initials: N
authors.lastname: Yamamtoto
authors.forename: Michio
authors.initials: M
authors.lastname: Tanaka
authors.forename: Mitsuaki
authors.initials: M
authors.lastname: Isobe
mesh_terms: D000818:Animals; D001283:Atrioventricular Node / Q000033:anatomy & histology* / Q000601:surgery*; D006328:Cardiac Catheterization / Q000295:instrumentation / Q000379:methods*; D002404:Catheterization / Q000295:instrumentation / Q000379:methods*; D004285:Dogs; D019723:Endoscopes; D004724:Endoscopy / Q000379:methods*; D005240:Feasibility Studies; D053685:Laser Therapy / Q000295:instrumentation / Q000379:methods*; D025321:Surgery, Computer-Assisted / Q000379:methods*; D016896:Treatment Outcome