Platypnea-orthodeoxia syndrome in a patient with a pre-existing patent foramen ovale successfully treated with an atrial septal occluder

Platypnea orthodeoxia syndrome is associated with dyspnea and arterial oxygen desamration accentuated by an upright posture. It can be secondary to an intracardiac shunt. We report a case of platypnea-orthodeoxia syndrome （POS） in a 58-year old male patient who had a pre-existing patent foramen ovale （PFO） and substantial pulmonary pathologies. He was successfully treated by percutaneous transcatheter closure of the PFO. Our case highlights the importance of recognition of this rare syndrome in patients who present with unexplained hy- poxia for whom transcatheter closure of the interatrial shunt can be safely carded out.