CONGRESS ABSTRACT

Introduction: Platypnea-orthodeoxia syndrome (POS) is a condition characterized by positional dyspnea, hypoxiemia and arterial oxygen desaturation triggered by upright position and relieved by supine decubitus. Pathophysiology of POS is based on mixture of deoxygenated venous blood with arterious blood. A Patent Foramen Ovale (PFO) is the most common cause of POS. Medical history: A 65-year-old female patient was admitted to the emergency department due to hypoxiemic- normocapnic respiratory failure. Ten days before, the patient underwent hip artroplasty due to fracture of femur. She was in therapy with low molecular weight heparin. Clinical data: At the admission the patient reported dyspnea, BP was 110/70 mmHg and HR was 100 bpm. It was started oxygen therapy. Arterial Blood Gases (ABGs) were: pCO2 37 mmHg, pO2 67 mmHg, SO2 95.4 %, P/F 216 mmHg. D-dimer plasma levels was elevated (2075 micro/l). Patient underwent computed tomography angiography in the suspect of acute pulmonary embolism and it showed arterial filling defects of dorsal segmental arteries at the level of the pyramid of the right lower lobe. The transthoracic echocardiogram showed normal right-sided chambers and moderate tricuspid valve regurgitation (PAPS 32 mmHg). PESI score: IV. An intermediate-low risk PE was identified. Adequate anticoagulation therapy was started. Diagnosis: ABGs showed persistent arterial oxygen desaturation which didn’t improve with therapy. Due to refractory respiratory failure, we suspected an interatrial defect. A transesophageal echocardiography revealed the presence of a multifenestrated PFO with a basal right to left shunt of intermediate grade while during Valsalva maneuver, echo contrast solution showed a severe right to left shunt and a presence of Eustachian Valve. A right heart catheterization showed normal parameters. ABGs in orthostatic position and in supine decubitus confirmed the presence of platypnea-orthodeoxia syndrome. Treatment: A percutaneous closure of PFO was performed with a occluder device with intra cardiac echography (ICE). After the procedure patient showed a progressive clinical improvement. Conclusion: Platypnea-ortodeoxia is a rare syndrome characterized by dyspnea and arterial oxygen desaturation in upright position associated with improvement of sign and symptom in supine decubitus. The patophysiological mechanism is based on the presence of right to left shunt. The closure of the PFO caused the regression of syndrome.