Inter-atrial septum dissection during atrial fibrillation ablation via atrial septal defect: A rare complication.

Catheter ablation has become an established treatment modality for atrial fibrillation, particularly in patients with refractory or intolerant responses to medical therapy. The Marshall-Plan has garnered interest in this field for its ability to achieve durable posterior mitral isthmus ablation. This anatomically-based approach combines alcohol ablation of the vein of Marshall with pulmonary vein isolation, mitral roof, and isthmus ablation, and a cavotricuspid isthmus line. Despite its effectiveness, procedural complications, although rare, must be considered. Here, we report a case of suspected inter-atrial septum dissection during Marshall-Plan atrial fibrillation ablation, complicated by the development of a saline transudative peri-cardial effusion. The study adheres to the Declaration of Helsinki.