PAY ATTENTION! AN UNUSUAL CASE OF DYSPNEA

Abstract

SESSION TITLE: Medical Student/Resident Cardiothoracic Surgery Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: October 18-21, 2020 INTRODUCTION: Platypnea-orthodeoxia is an uncommon syndrome characterized by dyspnea and hypoxemia in upright position that improves with recumbent position. It can occur due to intracardiac shunts, pulmonary arteriovenous shunts and ventilation perfusion mismatch. We present a unique and rare cause of platypnea-orthodeoxia syndrome. CASE PRESENTATION: A 68 years old man with history of coronary artery disease and COPD presented with acute onset chest pain and associated difficulty breathing. Patient did have several months’ history of exertional dyspnea which did not improve with rest this time. On presentation, patient was noted to be hypoxic with oxygen saturation of 88% and ABG showed PH 7.41, PaO2 47 mmHg and PaCO2 22.4 mmHg. Oxygen saturation improved to 94% with 3L of supplemental oxygen. EKG and troponin were unremarkable. CT PE was unremarkable for pulmonary embolism as well. IV heparin drip was started for suspected unstable angina and patient underwent cardiac catheterization that revealed non-obstructive coronary artery disease. Echocardiography showed ejection fraction of 55-60% with mild mitral and tricuspid regurgitationDuring the course of hospitalization, patient was noted to have intermittent positional hypoxemia. He had normal resting saturation on 2 L of oxygen which dropped to 88% sitting upright and dropped to 84% on 2 L of oxygen upon raising both arms. Platypnea-orthodeoxia syndrome was strongly suspected with possible intra-cardiac or intrapulmonary shunt. Meanwhile, CT chest was unremarkable for interstitial lung disease. Right heart catheterization revealed normal right atrial RA (68.9%) and pulmonary arterial PA (68.3%) saturation at rest but reduced RA (42.5%) and PA (43.2%) saturation with sitting up. Echocardiography with bubble study showed right-to-left shunting and trans-esophageal echocardiography revealed a small 0.5 cm atrial septal defect (ASD) with bidirectional shunting. Patient was diagnosed with Platypnea-orthodeoxia syndrome secondary to ASD. He was discharged home on supplemental oxygen and outpatient follow-up for ASD closure. DISCUSSION: Platypnea-orthodeoxia is a rare syndrome. Patent foramen ovale is the most common cardiac cause of platypnea-orthodeoxia syndrome followed by ASD. Transesophageal echocardiography is the best test to diagnose atrial septal defect but it is important to rule out pulmonary causes of platypnea-orthodeoxia syndrome as well. ASD is successfully treated with percutaneous closure and prognosis of is good after correction of the defect. CONCLUSIONS: Platypnea-orthodeoxia syndrome is rare syndrome but it can be easily recognized with careful history and physical examination. Reference #1: Henkin S, Negrotto S, Pollak PM, Cullen MW, O'Cochlain DF, Wright RS. Platypnea-Orthodeoxia Syndrome: Diagnostic Challenge and the Importance of Heightened Clinical Suspicion. Tex Heart Inst J. 2015;42(5):498-501. Published 2015 Oct 1. doi:10.14503/THIJ-14-4596 Reference #2: Kazawa S, Enomoto T, Suzuki N, et al. Platypnea-orthodeoxia Syndrome in a Patient with an Atrial Septal Defect: The Diagnosis and Choice of Treatment. Intern Med. 2017;56(2):169-173. doi:10.2169/internalmedicine.56.7728 Reference #3: PLATYPNEA ORTHODEOXIA SYNDROME: A RARE COMPLICATION OF IATROGENIC ATRIAL SEPTAL DEFECT. Bharat Avirneni, Christopher Rosse, Joseph Choo, Kalpan Desai. J Am Coll Cardiol. 2020 Mar, 75 (11 Supplement 1) 2799. DISCLOSURES: No relevant relationships by Muhammad Aamir, source=Web Response No relevant relationships by Muhammad Afzal, source=Web Response No relevant relationships by Saleha Dar, source=Web Response