title: Coronary sinus and fossa ovalis ablation: effect on interatrial conduction and atrial fibrillation.
abstract: BACKGROUND
  Interatrial conduction occurs via discrete pathways along the coronary sinus musculature, fossa ovalis region, and Bachman's bundle. We assessed the feasibility of altering interatrial conduction by selectively ablating two of these conduction pathways using a novel mesh electrode ablation catheter.
  
  
  METHODS
  Circular radiofrequency energy catheter ablation lesions were created in the proximal coronary sinus in four dogs and in both the fossa ovalis and the proximal coronary sinus regions in seven pigs. Interatrial conduction was assessed by analyzing intracardiac electrogram and noncontact isopotential mapping data. Inducibility of atrial fibrillation was assessed before and after ablation (in six pigs).
  
  
  RESULTS
  Ablation lesions in the proximal coronary sinus eliminated interatrial conduction along the coronary sinus musculature in four dogs and five of seven pigs. Ablation lesions in the fossa ovalis region eliminated interatrial conduction via midseptal pathways in six of seven pigs. Atrial fibrillation, inducible in five of seven pigs at baseline, was rendered noninducible in all five. There was no adverse effect on AV nodal conduction.
  
  
  CONCLUSIONS
  (1) Using a novel mesh electrode ablation catheter, we were able to ablate interatrial conduction pathways along the proximal coronary sinus and fossa ovalis regions. (2) This altered interatrial conduction and altered atrial fibrillation inducibility and maintenance. (3) Catheter ablation of interatrial conduction pathways may be useful in the therapy of atrial fibrillation.
authors.affiliation: Sarver Heart Center, University of Arizona, Tucson, Arizona 85724, USA. ottp@email.arizona.edu
authors.forename: Peter
authors.initials: P
authors.lastname: Ott
authors.forename: Malcolm M
authors.initials: MM
authors.lastname: Kirk
authors.forename: Charles
authors.initials: C
authors.lastname: Koo
authors.forename: Ding Sheng
authors.initials: DS
authors.lastname: He
authors.forename: Baishali
authors.initials: B
authors.lastname: Bhattacharya
authors.forename: Alfred
authors.initials: A
authors.lastname: Buxton
mesh_terms: D000818:Animals; D001281:Atrial Fibrillation / Q000503:physiopathology / Q000601:surgery*; D001283:Atrioventricular Node / Q000503:physiopathology; D017115:Catheter Ablation / Q000009:adverse effects / Q000295:instrumentation* / Q000379:methods*; D004195:Disease Models, Animal; D004285:Dogs; D004867:Equipment Design; D005240:Feasibility Studies; D006329:Heart Conduction System / Q000503:physiopathology / Q000601:surgery*; D012849:Sinoatrial Node / Q000473:pathology; D013552:Swine; D014693:Ventricular Fibrillation / Q000209:etiology