Right Atrial Mass With Pulmonary Embolism and Tricuspid Dysfunction: Features Favoring Right-Sided Infective Endocarditis

Right-sided infective endocarditis (RSIE) represents a minority of infective endocarditis cases but carries substantial morbidity due to embolic and hemodynamic complications, particularly in patients with intravenous drug use. We describe a 45-year-old man with intravenous drug use who presented in septic shock complicated by disseminated intravascular coagulation and peripheral gangrene. Blood cultures grew <i>Streptococcus agalactiae</i>. Multimodal cardiac imaging revealed a large, mobile right atrial mass prolapsing through the tricuspid valve, resulting in severe tricuspid regurgitation and associated pulmonary embolism. Despite diagnostic uncertainty between thrombus and infective vegetation, cumulative clinical, microbiologic, and imaging features supported a working diagnosis of RSIE. Given the prohibitive surgical risk, percutaneous aspiration using the AngioVac system (AngioDynamics, Latham, NY, USA) was pursued following multidisciplinary evaluation. This case highlights a practical escalation framework for percutaneous intervention in critically ill patients with right-sided cardiac masses when diagnostic certainty is limited but embolic risk and hemodynamic compromise are substantial.