Radiofrequency Ablation of a Focal Atrial Tachycardia Originating From the Marshall Ligament as a Trigger for Atrial Fibrillation

Abstract

A 66-year-old woman with a history of typical atrial flutter and atrial fibrillation was referred to our institution for radiofrequency ablation. In 1997, her atrial flutter was successfully ablated. During the next 4 years, she remained free of both arrhythmias. In 2001, the patient presented again with atrial fibrillation. During the subsequent electrophysiological study, the index arrhythmia was an incessant atrial tachycardia (AT), 170 bpm (Figure 1, left). A 3-dimensional electroanatomic map (CARTO; Biosense Webster, Inc) of the right atrium (RA) during tachycardia clearly demonstrated a tachycardia originating in the left atrium (LA) (Figure 2). Mapping of the LA through a transseptal puncture revealed an AT arising from a posterolateral LA focus, between the left superior pulmonary vein ostium and the atrioventricular groove (Figure 2). Endocardial recordings during AT from this region showed a discrete electrical potential (Marshall potential) preceding the atrial electrogram (Figure 1, right). Radiofrequency ablation targeting this area of early activation was successfully performed. The patient remains free of atrial arrhythmias at 3-month follow-up. This case indicates that in this particular patient, 2 triggers for atrial fibrillation were documented: an isthmus-dependent atrial flutter and an AT originating from the Marshall ligament.

Magnetic Electroanatomic Mapping of an Atrial Tachycardia Requiring Ablation Within the Coronary Sinus

“…Possibilities include the CS myocardial sleeve or the bundle within the ligament of Marshall (LOM). Both structures have been implicated as a source of focal AT including atrial fibrillation 8 . The presence of myocardium within the CS (myocardial sleeve) that extends 4 cm from the ostium has been demonstrated by Chauvin et al 9 Antz et al 10 showed the existence of discrete connections between the muscular CS sleeve and the left and right atrium 10 .…”

Feasibility and efficacy of minimally invasive stand-alone surgical ablation of atrial fibrillation. A single-center experience

“…Owing to the possibility of creating transmural lesions on the beating heart through alternative, less invasive incisions, surgical ablation is gaining ground in patients with atrial fibrillation. It is now also becoming general practice to treat atrial fibrillation in patients that are candidates for major surgery, such as mitral valve replacement/repair or coronary artery bypass graft, since this arrhythmia is an independent risk factor for increased postsurgical mortality; very good results have been reported [17–19]. …”

Atrial Tachycardia Arising From the Coronary Sinus Musculature

“…It could be possible that the origin of this tachycardia could be from the LOM (8) in some patients. However, the LOM is known to have extensive connections in the LA that may require ablation in the LA (8,17,18). The dissociation of the CS (P) by RFCA in LA (Fig.…”