Pulmonary Embolism and Right Heart Failure Associated With Lipomatous Atrial Septal Hypertrophy: A Case Report

BACKGROUND Lipomatous atrial septal hypertrophy (LASH) is a benign but uncommon condition characterized by excessive adipose tissue accumulation within the interatrial septum. Although most cases remain asymptomatic, large lesions may produce superior vena cava (SVC) obstruction. Acute pulmonary embolism as an initial presentation is rare. CASE REPORT A 75-year-old woman with a history of chronic obstructive pulmonary disease and hypertension experienced 7 days of progressively worsening exertional dyspnea, orthopnea, and lower-extremity edema, without chest pain, cough, or fever. Physical examination findings included tachypnea, hypertension, bilateral lower-extremity edema, elevated jugular venous pressure, and bibasilar crackles. Computed tomography pulmonary angiography - prompted by elevated D-dimer - demonstrated bilateral pulmonary emboli and a large LASH causing SVC obstruction with near-complete obliteration of the right atrium. Transthoracic echocardiography confirmed the presence of LASH. The absence of personal or family history of inherited thrombophilia, along with negative deep venous thrombosis findings on lower-extremity Doppler ultrasonography, suggested that pulmonary embolism and right heart failure were related to sluggish right atrial flow secondary to LASH-induced mechanical SVC obstruction. Clinical improvement was achieved with anticoagulation and diuretic therapy, followed by partial surgical resection of the interatrial septum in conjunction with coronary artery bypass grafting. Histopathologic examination confirmed LASH without evidence of inflammation or malignancy. CONCLUSIONS Symptomatic LASH causing SVC obstruction is extremely uncommon and rarely associated with pulmonary embolism. This case underscores the importance of recognizing LASH as a potential contributor to right heart failure and thromboembolism; it highlights echocardiography as an essential diagnostic modality when pulmonary embolism is suspected.