Isolation of canine coronary sinus musculature from the atria by radiofrequency catheter ablation prevents induction of atrial fibrillation.
BACKGROUND
The junction between the coronary sinus (CS) musculature and both atria contributes to initiation of atrial tachyarrhythmias. The current study investigated the effects of CS isolation from the atria by radiofrequency catheter ablation on the induction and maintenance of atrial fibrillation (AF).


RESULTS
Using an optical mapping system, we mapped action potentials at 256 surface sites in 17 isolated and arterially perfused canine atrial tissues containing the entire musculature of the CS, right atrial septum, posterior left atrium, left inferior pulmonary vein, and vein of Marshal. Rapid pacing from each site before and after addition of acetylcholine (0.5 μmol/L) was applied to induce AF. Epicardial radiofrequency catheter ablation at CS-atrial junctions isolated the CS from the atria. Rapid pacing induced sustained AF in all tissues after acetylcholine. Microreentry within the CS drove AF in 88% of preparations. Reentries associated with the vein of Marshall (29%), CS-atrial junctions (53%), right atrium (65%), and pulmonary vein (76%) (frequently with 2-4 simultaneous circuits) were additional drivers of AF. Radiofrequency catheter ablation eliminated AF in 13 tissues before acetylcholine (P<0.01) and in 5 tissues after acetylcholine. Radiofrequency catheter ablation also abbreviated the duration of AF in 12 tissues (P<0.01).


CONCLUSIONS
CS and its musculature developed unstable reentry and AF, which were prevented by isolation of CS musculature from atrial tissue. The results suggest that CS can be a substrate of recurrent AF in patients after pulmonary vein isolation and that CS isolation might help prevent recurrent AF.
From the Krannert Institute of Cardiology, Indiana University School of Medicine, Indianapolis (H.M., D.P.Z., S.T.M., J.W.); Department of Cardiovascular Therapeutics/Cardiovascular Medicine, Okayama University Graduate School of Medicine, Okayama, Japan (H.M., S.T.M.); and Department of Pharmaceutical Sciences, College of Pharmacy, Northeast Ohio Medical University, Rootstown (J.W.). hmorita@cc.okayama-u.ac.jp.
Hiroshi
H
Morita
From the Krannert Institute of Cardiology, Indiana University School of Medicine, Indianapolis (H.M., D.P.Z., S.T.M., J.W.); Department of Cardiovascular Therapeutics/Cardiovascular Medicine, Okayama University Graduate School of Medicine, Okayama, Japan (H.M., S.T.M.); and Department of Pharmaceutical Sciences, College of Pharmacy, Northeast Ohio Medical University, Rootstown (J.W.).
Douglas P
DP
Zipes
From the Krannert Institute of Cardiology, Indiana University School of Medicine, Indianapolis (H.M., D.P.Z., S.T.M., J.W.); Department of Cardiovascular Therapeutics/Cardiovascular Medicine, Okayama University Graduate School of Medicine, Okayama, Japan (H.M., S.T.M.); and Department of Pharmaceutical Sciences, College of Pharmacy, Northeast Ohio Medical University, Rootstown (J.W.).
Shiho T
ST
Morita
From the Krannert Institute of Cardiology, Indiana University School of Medicine, Indianapolis (H.M., D.P.Z., S.T.M., J.W.); Department of Cardiovascular Therapeutics/Cardiovascular Medicine, Okayama University Graduate School of Medicine, Okayama, Japan (H.M., S.T.M.); and Department of Pharmaceutical Sciences, College of Pharmacy, Northeast Ohio Medical University, Rootstown (J.W.).
Jiashin
J
Wu
D000109:Acetylcholine; D000200:Action Potentials; D000818:Animals; D001281:Atrial Fibrillation / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control*; D018780:Body Surface Potential Mapping; D002304:Cardiac Pacing, Artificial; D017115:Catheter Ablation; D054326:Coronary Sinus / Q000503:physiopathology / Q000601:surgery*; D004195:Disease Models, Animal; D004285:Dogs; D006325:Heart Atria / Q000503:physiopathology / Q000601:surgery; D008297:Male; D013997:Time Factors
D000109:Acetylcholine
atrial fibrillation; catheter ablation; coronary sinus; optical Vm mapping