Transcatheter balloon dilatation of cor triatriatum dexter with percutaneous atrial septal defect closure

Cor triatriatum dexter is an extremely rare congenital heart defect and cause of hypoxia in adults. We describe a case of cor triatriatum dexter discovered incidentally due to an iatrogenic atrial septal defect. The cor triatriatum dexter resolved with balloon dilation - a novel technique to manage this rare clinical condition. <Learning objective: Management of cor triatriatum dexter, an exceptionally rare diagnosis, has often been thought to be surgical. However, percutaneous intervention may be considered in select clinical situations.>