Divided atrium (or Cor triatriatum) dexter (DAD) is a rare congenital cardiopathy, usually associated with other anomalies; isolated forms are even rarer. We report the case of an 84-year-old woman presenting with isolated DAD complicated by right-left atrial shunt through patent foramen ovale (PFO), revealed by right cardiac failure and severe hypoxemia. Late destabilization was caused by total superior vena cava thrombosis, related to her pacemaker. Given the overall context, complete percutaneous treatment was performed, associating PFO occlusion and stent implantation in the right atrial membrane, providing total regression of symptoms. Thus, percutaneous correction of DAD appears to be safe and effective.