Pulmonary Embolism Presenting as Recurrent Syncope and Visual Disturbances in a Patient With Protein C Deficiency: An Atypical Emergency Department Presentation

Pulmonary embolism (PE) is a potentially life-threatening cardiovascular emergency that can present with atypical, non-respiratory manifestations, leading to diagnostic delay. We describe a 41-year-old previously healthy man who presented with recurrent episodes of syncope, giddiness, and transient blurring of vision over five days. Neurological and ocular examinations, as well as non-contrast computed tomography (CT) of the head, were unremarkable. Point-of-care echocardiography revealed global ventricular hypokinesia, dilated right atrium and ventricle, and reduced tricuspid annular plane systolic excursion (TAPSE=12 mm). CT pulmonary angiography confirmed acute bilateral PE. Further work-up demonstrated decreased protein C activity (40%), consistent with hereditary protein C deficiency. The patient was treated promptly with anticoagulation and achieved full recovery. This case highlights the protean nature of PE, which may masquerade as a neurological illness in the absence of classical respiratory or hemodynamic signs. Bedside echocardiography served as a critical diagnostic adjunct, allowing early recognition of right ventricular dysfunction and facilitating timely intervention. The detection of an inherited thrombophilia underscores the importance of evaluating for hypercoagulable states in young patients presenting with unprovoked venous thromboembolism. Emergency physicians should therefore maintain a high index of suspicion for PE in patients with unexplained syncope or transient neurological symptoms. Early imaging and bedside echocardiography remain pivotal for rapid diagnosis, and thrombophilia screening aids in guiding secondary prevention strategies.