At the Heart of the Diagnosis: A Case of Systemic Lupus Erythematosus Presenting as Cardiac Tamponade.

Systemic lupus erythematosus (SLE) is a heterogenous, systemic disease characterized by the production of pathogenic autoantibodies against nuclear antigens. Although the most common cardiac manifestation of SLE is pericardial effusions, their progression to cardiac tamponade is rare and has an incidence between 1-3%. We describe a case of a 42-year-old Hispanic woman who presented with severe shortness of breath, vague chest pain, and hemodynamic compromise secondary to cardiac tamponade. The patient's underlying etiology of cardiac tamponade was attributed to a new diagnosis of SLE based on the 2019 European Alliance of Associations for Rheumatology/American College of Rheumatology classification (EULAR/ACR) criteria for SLE. The patient's treatment consisted of a pericardial window and immunosuppressive therapy with corticosteroids, Mycophenolate, and hydroxychloroquine. This case aims to increase awareness of SLE as a possible differential diagnosis of cardiac tamponade in the appropriate clinical setting.