Catheter Ablation -> Atrial Fibrillation & Atrial Flutter: -> Ablation Techniques D-PO02 - Poster Session II (ID 47) Poster

D-PO02-145 - Electrical Isolation Of The Marshall Bundle By Radiofrequency Catheter Ablation (ID 1030)


Background: The vein of Marshall (VOM) is surrounded by a muscular bundle, the Marshall bundle (MB), which is one of the arrhythmogenic sources of atrial fibrillation (AF) and electrically connects to either the left atrial (LA) myocardium or coronary sinus (CS) musculature. By eliminating such electrical connections using radiofrequency (RF) catheter ablation, the MB might be electrically isolated.
Objective: Using radiofrequency (RF) catheter ablation, the MB might be electrically isolated, which we attempted to prove in this study.
Methods: This study consisted of 20 patients (64±10 years old, 5 females) who underwent an MB isolation for non-paroxysmal AF. After the pulmonary vein isolation, we performed venography of the VOM and inserted a 2Fr electrode catheter into the VOM. An RF application was delivered to eliminate the MB electrograms from both the LA and CS when the MB was considered to be arrhythmogenic. The outcome of the MB isolation by RF energy applications was evaluated.
Results: The representative case of MB isolation is shown in Figure which shows complete electrical isolation of the MB (upper panel) and the exit block of the MB revealed by electrical pacing from the VOM catheter electrodes (lower panel). An MB isolation was achieved in 14 patients (70%). Out of those, a complete or partial MB isolation was accomplished in 7 patients (35%) each. During a follow up of 23±11 months, 18 patients (90 %) maintained sinus rhythm (SR).
Conclusion: RF applications targeting recordings from an electrode catheter in the VOM was feasible and the MB could be electrically isolated. Elimination of the MB would be a clear endpoint for patients with an arrhythmogenic MB.