CONGRESS ABSTRACT

Platypnea-orthodeoxia syndrome (POS) is rare.It is characterized by dyspnea in the upright position (platypnea) and hypoxemia (orthodeoxia) that improves in the supine position. Case report:A 78-year-old woman is admitted to the hospital for domestic crush trauma with bilateral ilio-ischio-pubic fracture.She was bedridden for 70 days.When she resumed mobilization,dyspnea and orthostatic oxyhemoglobin desaturation from 95% to 75% appeared with the transition from the supine to the upright position.She was admitted to hospital: hypoxemia improved with 40% oxygen,but then progressed with the need for 100% oxygen.POS was suspected and 2D C-Doppler echocardiogram,Transcranial ECHO-Doppler and transesophageal echocardiogram were performed.The diagnosis was:POS due to patent foramen ovale (PFO) and severe right-to-left shunt; ectasia of the ascending aorta and severe regurgitation.Coronary angiography and CT of the aorta were performed,which revealed ectasia and lengthening of the ascending aorta and compression of the right atrium (AR), anterior wedge of D7.The patient underwent surgery in the Cardiac Surgery Department of the Policlinico aortic valve replacement with Perimount Magna Ease n.21 bioprosthesis, closure by suturing of the foramen ovale (FO), with normalization of oxyhemoglobin parameters.Discussion:A drop in SaO2 of >5% or PaO2 of >4 mmHg when moving from the supine to the upright position diagnoses POS. POS has two factors:an anatomical one in the form of interatrial communication and a functional one that creates deformity in the atrial septum, with direction of the shunt flow in orthostatism. In the patient the anatomical factor is the FO while the functional factor is the aortic ectasia. Savage et al found 2 cases associated with aortic aneurysm in which there is: compression of the AR by the aneurysm with increase in AR pressure and opening of the FO and deformation of the AR by the aneurysm, which creates a blood flow from the inferior vena cava (IVC) to and through the FO.FO closure is indicated to treat POS.For aortic regurgitation, valve replacement was performed and the elongated aorta was shortened by aortotomy, with normalization of the flow direction from the IVC and reduction of compression of the AR. In the patient,the trigger may have been the crushing trauma which, with the dorsal vertebral fracture, created a change in the relationship between the aorta and the AR, increasing the compression of the already ectatic aorta on the AR.