Platypnoea-orthodeoxia syndrome and hemidiaphragm paralysis

A woman in her 70s was admitted to hospital with worsening shortness of breath and no prior respiratory history of note. This patient's shortness of breath was posture-dependent; symptoms were markedly worse and oxygen saturations were lower on sitting upright than in recumbency. Her shortness of breath had started several weeks prior to admission and had slowly worsened. Chest X-ray revealed a raised right hemidiaphragm. Further investigation revealed a patent foramen ovale, which was managed with percutaneous closure. This is one of several cases that demonstrate right-to-left shunting through a septal defect secondary to right hemidiaphragmatic paralysis. However, previous reports have not provided a clear guide for management of these cases. We suggest where patients are admitted with new onset breathlessness and platypnoea-orthodeoxia, a septal defect should be suspected. In this report, we have suggested a flowchart for the investigation and management of platypnoea-orthodeoxia syndrome.