Platypnea-orthodeoxia syndrome : an atypical clinical case

Platypnea-orthodeoxia is un uncommon syndrome associating dyspnea and refractory hypoxemia induced by upright posture. Multiple etiologies can be brought upfront: cardiac shunt (patent atrial septal defect), pulmonary resection and hepatopulmonary syndrome amongst others. Its diagnosis is made by ultrasonography, often misled by its nonspecific clinical presentation. We present an atypical case of patent atrial septal defect. In our clinical case, the latent defect had been made patent by an architectural cardiac modification following a bulky pericardial cyst located near the right lung base. The therapy is that of the shunt, surgical or percutaneous.