Feasibility of a left atrial electrical disconnection procedure for atrial fibrillation using transcatheter radiofrequency ablation.
BACKGROUND
An effective, catheter-based treatment for persistent atrial fibrillation (AF) remains elusive. This study assessed the feasibility of transcatheter left atrial (LA) electrical disconnection and its effect on AF inducibility.


RESULTS
Thirteen anesthetized swine underwent noncontact mapping of the right atrium (RA) during coronary sinus (CS) pacing. Sites of earliest RA activation were identified using isopotential maps. An ablation catheter was navigated to these sites and a cluster of radiofrequency (RF) lesions applied until earliest activation shifted to a new site. The procedure was repeated until the atria were electrically disconnected. AF induction was attempted before and after ablation. Earliest RA activation was the CS os during proximal CS pacing and Bachmann's bundle during distal CS pacing. These two sites were successfully ablated in all 13 animals. Earliest activation then shifted to the fossa ovalis. RF energy was applied at a median of 2.5 sites (range 1 to 5) around the fossa, then at sites in the triangle of Koch, septum, cavotricuspid isthmus, and posterior wall. Atrial electrical disconnection was achieved in 10 of 13 animals (5 LA electrical disconnection, 3 RA electrical disconnection, 2 biatrial electrical disconnection with complete heart block). After atrial electrical disconnection, the LA became electrically silent. Before ablation, AF was inducible in every animal. After atrial electrical disconnection, AF was inducible in 3 of 10 animals.


CONCLUSIONS
Atrial electrical disconnection is feasible using noncontact mapping and RF ablation. Successful electrical disconnection of the atria reduces AF inducibility. This approach is worthy of further evaluation as a management strategy for persistent AF, combined with device therapies.
Betts
T R
TR
Wessex Cardiothoracic Center, Southampton University Hospitals, United Kingdom. timbetts@compuserve.com
Roberts
P R
PR
Morgan
J M
JM
D000818:Animals; D001281:Atrial Fibrillation / Q000601:surgery*; D018780:Body Surface Potential Mapping; D017115:Catheter Ablation; D003331:Coronary Vessels / Q000473:pathology / Q000601:surgery; D004195:Disease Models, Animal; D005240:Feasibility Studies; D006325:Heart Atria / Q000473:pathology / Q000601:surgery*; D006329:Heart Conduction System / Q000473:pathology / Q000601:surgery; D006346:Heart Septum / Q000473:pathology / Q000601:surgery; D008955:Models, Cardiovascular; D009336:Necrosis; D013552:Swine; D016896:Treatment Outcome