Platypnea-Orthodeoxia Syndrome Caused by Patent Foramen Ovale Successfully Treated With Percutaneous Closure

Platypnea-orthodeoxia syndrome (POS) is characterized by dyspnea and hypoxemia that worsen in the upright position and improve when supine. Both an anatomical intracardiac defect and functional factors that cause posture-dependent right-to-left shunting are required for manifestation.

A 74-year-old woman with hypertension and dyslipidemia presented with progressive dyspnea and hypoxemia without evidence of pulmonary disease. Her oxygen saturation was 80% to 83% in the upright position versus 95% to 99% in the supine position, suggesting POS. Transesophageal echocardiography revealed a patent foramen ovale (PFO) with posture-dependent shunting and an atrial septal aneurysm. Computed tomography revealed aortic elongation compressing the right atrium. She underwent percutaneous PFO closure using a Gore Cardioform septal occluder, resulting in complete resolution of hypoxemia.

This case highlights the importance of positional assessment and the utility of sitting-position echocardiography to detect posture-dependent right-to-left shunting that may be missed on conventional supine imaging.

Sitting-position transesophageal echocardiography is a useful diagnostic method for identifying posture-dependent shunting in POS, and percutaneous PFO closure provides definitive therapy with rapid improvement in oxygenation.