Platypnea orthodeoxia is a rare disorder characterized by
dyspnea and arterial desaturation, exacerbated by the upright position and relieved when the subject is recumbent. We report the case of a 79-year old woman admitted to hospital with
dyspnea who was thought to have restrictive ventilatory impairment due to
osteoporosis and severe
kyphosis. Interestingly, the
dyspnea was aggravated in the upright position, whereas the symptoms improved in the supine position. Arterial blood gas analysis confirmed
orthodeoxia. The lung function test showed only a mild obstructive and restrictive ventilation disorder. Echocardiography revealed a
patent foramen ovale and an
aneurysm of the atrial septum protruding into the left atrium, despite normal right atrial pressure. Transesophageal echocardiography showed a prominent Eustachian valve guiding a blood flow from the inferior vena cava directly onto the atrial septum, thereby pushing open the
patent foramen ovale. Contrast-enhanced echocardiography confirmed a spontaneous right-to-left shunt through the
patent foramen ovale. It was assumed that the
platypnea-
orthodeoxia was caused by a prominent Eustachian valve redirected to the
patent foramen ovale as a result of severe
osteoporosis with subsequent thoracic
kyphosis and a change in the position of the entire heart. The patient underwent permanent transcatheter closure of the
patent foramen ovale after hemodynamic assessment had confirmed a significant right-to-left shunt through it. After the procedure the arterial
oxygen pressure increased significantly in the upright position and
dyspnea improved.