Pseudo-pulmonary Embolism – A Case of Hypoxemia Associated with Right-to-left Shunt

Introduction

Platypnea orthodeoxia is a rare syndrome characterized by dyspnea and decreased arterial oxygen saturation when passing from the dorsal decubitus position to the sitting or upright position. It usually results from an intracardiac right-to-left shunt; however, the pathophysiological mechanism responsible for the positional nature of the shunt has not been clarified^,. We report a case of dyspnea and orthostatic hypoxemia, which was attributed to a right-to-left shunt due to atrial septal defect (ASD).

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