Successful Multi-chamber Catheter Ablation of Persistent Atrial Fibrillation in Cor Triatriatum Sinister

Cor triatriatum sinister is a rare congenital cardiac anomaly with an incidence of between 0.1 and 0.4% [1,2] whereby the left atrium is functionally and anatomically divided into two separate chambers by a thin membrane. Although there are a limited number of reports of successful ablation of left atrial focal tachycardia and simple pulmonary vein isolation in individuals with cor triatriatum sinister [3-5], these involved ablation within a single atrial chamber only. To the best of our knowledge ablation in all three atrial chambers has not previously been described. We report a case of extensive ablation of long-lasting persistent atrial fibrillation (AF) encompassing pulmonary vein antral ablation with isolation combined with additional substrate modification involving ablation within both the supero-posterior and infero-anterior left atrial chambers in addition to the right atrium and the coronary sinus a four chambered ablation approach.