Uncommon late presentation of platypnea-orthodeoxia syndrome

Platypnea-orthodeoxia syndrome (POS) is a rare clinical condition characterized by dyspnea and deoxygenation in the sitting or upright position relieved by supine position. The certain pathophysiological mechanisms is unknown, and this syndrome is frequently associated with other clinical entities, such as an intracardiac shunt, a pulmonary vascular shunt or a ventilation–perfusion mismatch. In cardiac POS, an atrial septal defect or patent foramen ovale (PFO) allows communication between the right- and left-sided circulations. A second defect, such as an enlarged ascending aorta, prominent eustachian valve, loculated pericardial effusion, or pneumonectomy, contributes to dynamic right-to-left shunting through the interatrial connection. The appropriate management is still debated; surgical or transcatheter percutaneous approaches to close the atrial septal defect or PFO may be considered. We describe an unusual presentation of late-onset POS in a 79-year-old man with a PFO and a dilated ascending aorta, successfully treated by percutaneous PFO closure. Our case suggests that the diagnosis of this rare clinical syndrome can be challenging in older patients complaining dyspnea, but it has important therapeutic implications and must be actively investigated in the presence of position-dependent hypoxemia. The percutaneous PFO closure in patients with POS is feasible, safe and effective even in elderly with comorbidities and frailty.