Anatomical Considerations Regarding Catheter Ablation of Atrial Fibrillation in Cor Triatriatum Sinister: A Case Report and Review of the Literature

Katetrska ablacija atrijske fibrilacije pri bolnikih s cor triatriatum sinister: opis primera in pregled literature

Abstract

Introduction: Cor triatriatum sinister (CTS) is a rare congenital cardiac defect. Catheter ablation of atrial fibrillation (AF) in patients with CTS has important anatomical considerations.

Case presentation: A 49-year old female patient with a known CTS was referred to our institution for catheter ablation of symptomatic paroxysmal AF. Echocardiography revealed a dilated left atrium, which was split into two separate compartments by a thin fibromuscular membrane. A second membranous structure, in front of the left pulmonary vein (PV) ostia, was noted on the preprocedural magnetic resonance scan. The procedure was guided by intracardiac echocardiography and fluoroscopy. A 3D-electroanatomic map was created and the right PVs were isolated. The left PVs could not be mapped and isolated. The patient was discharged the following day without complications, and has remained entirely asymptomatic for over one year.

Discussion: Catheter ablation in patients with AF and a CTS appears to be a feasible rhythm control treatment modality. Most published literature details preprocedural and intraprocedural CTS assessment with different imaging modalities, as well as different ablation strategies based on the arrhythmia type. To the best of our knowledge, an additional membranous structure in front of the left PVs has not been reported.