Category: Clinical Sciences/Health Conditions
Platypnea-orthodeoxia syndrome secondary to position dependent right-to-left inter-atrial shunt
An 80 year-old male with a history of multiple thoracic compression fractures and kyphoscoliosis presented with several months of dyspnea when standing and functional decline. The patient’s oxygen saturation was in the 90’s while supine but consistently dropped to the 60’s with standing or sitting upright. Increased supplemental oxygen had no effect on blood oxygen saturation when standing. Physical therapy and occupation therapy worked with the patient on bed level exercises due to poor upright activity tolerance. No significant initial functional improvements were seen. Transthoracic echocardiogram showed no inter-atrial shunt and right-sided cardiac catheterization revealed normal pressures. The patient was eventially found to have a positional right to left inter-atrial shunt on transesophageal echocardiogram preformed in the Semi-Fowler’s position. The patient underwent percutaneous closure of the defect and was admitted to inpatient rehabilitation. He progressed functionally from moderate/minimal assistance to supervision with ambulation and activities of daily living.
Platypnea-orthodeoxia syndrome is a rare disorder consisting of dyspnea and decreased arterial oxygenation with a right-to-left vascular shunt that only occurs with upright posture. It was first described in 1949 and only about 200 cases have been published. There are several case reports of patients with vertebral compression fractures and an inter-atrial defect who developed platypnea-orthodeoxia syndrome. It is thought that the anatomical changes combined with gravity can cause the aorta to pull on the inter-atrial septum and open previously undiagnosed inter-atrial defects such as an atrial septal defect, patent foramen ovale, or atrial septal aneurysm can become pathologic. The rehabilitation gains for our patient were significant only after closure of the defect.
Patients diagnosed with platypnea-orthodeoxia syndrome need correction of their right-to-left vascular shunt to make significant functional gains.