Large, Life-Threatening Right Ventricular and Pulmonary Artery Thrombus Revealing Antiphospholipid Syndrome: The Role of Risk Stratification and Thrombolytic Therapy

Right ventricular thrombus in the setting of acute pulmonary embolism is an uncommon and potentially life-threatening finding associated with a high risk of hemodynamic deterioration.The optimal management remains controversial, particularly in patients with an extensive thrombotic burden but without overt hemodynamic instability.We report a case of a patient presenting with an extensive thrombus occupying the right ventricle and extending into the pulmonary artery.Multimodality imaging demonstrated a significant thrombotic burden with right ventricular involvement and confirmed acute pulmonary embolism.Echocardiographic assessment revealed right ventricular thrombus and signs of right ventricular pressure overload.Based on the clinical presentation, imaging findings, and right ventricular involvement, the patient was classified as having intermediate-high-risk pulmonary embolism.Given the large mobile right ventricular thrombus with pulmonary arterial extension, profound hypoxemia (oxygen saturation: 54%) on room air, and severe tachypnea (45 breaths/min), systemic thrombolysis was considered despite the absence of hemodynamic collapse.After multidisciplinary discussion, an individualized treatment decision was made to administer reduced-dose tenecteplase (0.25 mg/kg; 15 mg).Marked clinical improvement was observed within 24 hours, with no major bleeding complications.Further investigations revealed antiphospholipid syndrome as the underlying prothrombotic condition.At three-month follow-up, the patient remained clinically stable, with a marked reduction in the residual right ventricular thrombus and resolution of the pulmonary trunk thrombus.This case highlights the importance of early echocardiographic identification of right ventricular thrombus in patients with pulmonary embolism and the role of multimodality imaging in therapeutic decision-making.It also illustrates the potential role of reduced-dose systemic thrombolysis in selected patients with intermediate-high-risk pulmonary embolism and extensive intracardiac thrombotic burden.Recognition of the underlying prothrombotic disorder is essential for guiding long-term anticoagulation and preventing recurrent thromboembolic events.