Platypnea Orthodeoxia Syndrome in a Patient With Pulmonary Arterial Hypertension

Platypnea orthodeoxia syndrome (POS) is a rare syndrome traditionally defined as dyspnea or hypoxemia observed when changing from a recumbent to an upright or seated position. A patent foramen ovale (PFO) is often part of the underlying pathophysiology. Here, a 70-year-old woman with known PFO presented with new symptoms of a POS. A pulmonary arterial hypertension (PAH), treated with ambrisentan for years, was also known. In order to clarify the etiology of the new hemodynamic state, we performed a transesophageal echocardiography (TEE) in an upright position, which excluded a PFO-related cause of symptoms. A further investigation showed a chronic obstructive pulmonary disease, the treatment of which relieved of symptoms. This is the first described case of POS in patient with PAH. Although PFO is a common cause of POS and a PFO closure is often advised, careful differential diagnosis should be kept in mind. J Med Cases. 2017;8(6):187-190 doi: https://doi.org/10.14740/jmc2840e