Abstract
Platypnea-orthodeoxia syndrome (POS) is an uncommon yet clinically significant medical phenomenon characterized by dyspnea, a distressing symptom manifesting as breathlessness upon assuming an upright position, which notably improves upon reclining. In stark contrast to orthopnea, where dyspnea worsens in a supine position, POS uniquely presents with decreased blood oxygen saturation upon transitioning from lying down to standing up. This syndrome poses diagnostic challenges due to its subtle symptomatology and requires a high index of clinical suspicion for accurate identification. Herein, we present a case of a 79-year-old female with a complex medical history, notably encompassing deep vein thrombosis (DVT) and subsequent pulmonary embolism (PE) necessitating long-term anticoagulation with warfarin, a history of breast cancer status post lumpectomy and chemotherapy, hypertension, and chronic kidney disease (CKD). The patient was admitted from a living facility with persistent hypoxemia and clinical features suggestive of POS. Despite comprehensive physical examination and routine laboratory investigations, no overt abnormalities were discerned. However, echocardiography unveiled a severe patent foramen ovale (PFO) with right-to-left shunting, corroborating the diagnosis of POS. Subsequently, percutaneous closure of the PFO using the GORE CARDIOFORM septal occluder was performed, with fluoroscopy confirming successful device placement within the atrial septum. Remarkably, the patient demonstrated significant improvement in oxygenation post-procedure, prompting her discharge within 2 days. POS, though rare, holds substantial clinical significance owing to its potential to precipitate considerable morbidity and mortality. The pathophysiological basis of POS lies in the discordance between pulmonary and systemic blood flow, culminating in arterial desaturation upon assuming an upright posture. Timely recognition and intervention are imperative to mitigate symptom burden and avert the progression of associated complications. Early diagnosis facilitates the implementation of targeted therapeutic strategies, thereby alleviating dyspnea and forestalling adverse sequelae stemming from this syndrome. As such, heightened awareness among healthcare practitioners regarding the nuanced presentation of POS is paramount to expedite appropriate management and optimize patient outcomes.