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).
Conclusion: 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.
Copyright © 2010 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.