Platypnea-orthodeoxia Syndrome Associated with a Thoracic Vertebral Fracture Following a Car Accident

Abstract

Platypnea-orthodeoxia syndrome (POS) is a rare clinical condition defined by the presence of dyspnea and deoxygenation accompanying changing from a supine to an upright position. We experienced the case of a 75-year-old woman who developed severe acute dyspnea after a car accident. Detailed history taking and a physical examination offered important clues that helped to make an accurate diagnosis of POS. The mechanism of onset is unique and rare; however, it is important for clinical cardiologists to keep this possibility in mind when making a differential diagnosis.

Unusual case of preoperative hypoxaemia

“…This anatomical change may have altered the direction of the jet of venous return to the right atrium resulting in increased flow through a pre-existing large PFO. This postulated mechanism has been previously described by Fukuoka et al 1 in a case of platypneoa orthodexia syndrome due to a vertebral fracture post a car accident.…”

“…PFOs occur in 25% of the normal population3 and may become pathological in the form of a right-to-left shunt if there is pulmonary hypertension. Previously documented acquired anatomic causes, other than kyphosis,1 include lung resection,4 aortic dilatation5 and spinal cord injury 6. In lung resection, the problem can be due to an altered mediastinal anatomy displacing the interatrial septum in relation to a fixed inferior vena cava 4.…”

Platypnoea–orthodeoxia syndrome exacerbated by kyphosis progression

“…It seems that the POS onset in this case was affected by an atrial septum deformity, elongation of the ascending aorta, the influence of cardiac surgery and kyphosis progression. A case of POS onset due to a thoracic fracture after a traffic accident has been reported 6. As shown in figure 6, the deviation ofthe spine due to the progression of kyphosis apparently proceeded over time.…”

Platypnea-orthodeoxia Syndrome Induced by Multiple Vertebral Compression Fractures and an Atrial Septal Defect

“…In our case, based on the patient's clinical course, her multiple vertebral compression fractures were suspected to have triggered the exacerbation of the RL shunting. To the best of our knowledge, only three cases of POS induced by vertebral fractures have been reported in the English literature ( 4 , 6 , 7 ). A possible etiological mechanism to explain the induction of POS by vertebral fractures is as follows: the multiple vertebral compression fractures caused kyphosis and the subsequent distortion of the aorta resulting in right atrial compression and increased RL flow through the ASD.…”