Identification and catheter ablation of extracardiac and intracardiac components of ligament of Marshall tissue for treatment of paroxysmal atrial fibrillation

Introduction: The ligament of Marshall is a left atrial neuromuscular bundl e with sympathetic innervation that may be a source of atrial fibrillation (AF)-inducing automatic activity. Methods and Results: Twenty-four patients with paroxysmal AF (including 18 with adrenergic AF) and 25 with other arrhythmias underwent catheter mappin g, In cases of adrenergic AF, radiofrequency ablation was attempted when Ma rshall potentials were recorded. Patients were followed for 2 months before and 11.2 +/- 4.2 months after the procedure. Catheterization of the distal superoposterior coronary sinus was feasible in 14 patients with AF (10 wit h adrenergic AF) and 12 patients without AE, A discrete Marshall potential was recorded in 12 patients with AF versus 3 patients without AF (P = 0.004 ), In 10 patients with adrenergic AF, this potential followed the atrial el ectrogram during sinus rhythm by 26 +/- 5 msec on left atrial recordings an d 24 +/- 4 msec on coronary sinus recordings, and preceded it during atrial ectopy by 29 +/- 5 msec and 26 +/- 5 msec, respectively. It was abolished by epicardial(n = 1), endocardial (n = 4), or combined epicardial and endoc ardial ablation (n = 5), Severs patients with ablation showed significant r eductions in adrenergic AF, whereas no significant change was seen in 8 adr energic AF patients not undergoing ablation (P = 0.004), No improvement was seen in 3 of 4 patients with only endocardial ablation, whereas all 6 pati ents with epicardial ablation improved OP = 0.033), Conclusion: Recording of Marshall potential is feasible in patients with pa roxysmal AF, Combined epicardial and endocardial catheter ablation of ligam ent of Marshall tissue may reduce the paroxysms of adrenergic AF.