title: Left atrial coronary perfusion territories in isolated sheep hearts: implications for atrial fibrillation maintenance.
abstract: BACKGROUND
  The role of coronary perfusion in the maintenance of atrial fibrillation (AF) electrical sources that anchor to the posterior (wall of the) left atrium (PLA) has been incompletely investigated. We hypothesized that the PLA-pulmonary vein region is perfused by branches originating from both the right and left coronary arteries.
  
  
  OBJECTIVE
  The purpose of this study was to evaluate whether branches originating from the right and left coronary arteries could serve as conduits to chemically ablate restricted PLA regions.
  
  
  METHODS
  In Langendorff-perfused sheep hearts, the right anterior and left anterior atrial arteries (RAAA and LAAA) and the branches of the left circumflex artery (LCX) were identified as main coronary artery branches perfusing the atria. During sustained AF, 20-mL boluses of cold Tyrode's solution (4°C) was injected into each artery to determine changes in dominant frequency. The injection that yielded the largest dominant frequency decrease indicated the coronary branch to be subsequently perfused with ethanol. Ethanol was selectively injected into the LAAA (n = 4), LCX (n = 4), or RAAA (n = 1).
  
  
  RESULTS
  Six of nine AF cases rapidly terminated upon ethanol perfusion. In those hearts and in eight additional preparations (n = 17), Congo red and Evans blue was subsequently perfused into the remaining atrial branches. The perfusion territories were classified as triple-vessel PLA perfusion (n = 4), LAAA-dominant PLA perfusion (n = 5), balanced double-vessel PLA perfusion (n = 5), and LCX or RAAA dominant (n = 3).
  
  
  CONCLUSIONS
  PLA coronary perfusion relies on a variable contribution of right and left coronary branches. Regional irrigation of ethanol in well-delineated PLA perfusion territories enabled ablation of high-frequency sites during AF.
authors.affiliation: Center for Arrhythmia Research, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan 48108, USA.
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Yamazaki
authors.forename: Sherry
authors.initials: S
authors.lastname: Morgenstern
authors.forename: Matthew
authors.initials: M
authors.lastname: Klos
authors.forename: Katherine
authors.initials: K
authors.lastname: Campbell
authors.forename: Daniel
authors.initials: D
authors.lastname: Buerkel
authors.forename: Jérôme
authors.initials: J
authors.lastname: Kalifa
mesh_terms: D055011:Ablation Techniques; D000818:Animals; D001281:Atrial Fibrillation / Q000503:physiopathology* / Q000601:surgery; D002304:Cardiac Pacing, Artificial; D017115:Catheter Ablation; D003326:Coronary Circulation; D003331:Coronary Vessels / Q000503:physiopathology; D000431:Ethanol / Q000494:pharmacology; D006325:Heart Atria / Q000503:physiopathology; D007552:Isotonic Solutions / Q000494:pharmacology; D011667:Pulmonary Veins / Q000503:physiopathology; D034561:Sheep, Domestic
chemical_list: D007552:Isotonic Solutions; C037692:Tyrode's solution; D000431:Ethanol