Chiari Network: An Innocent Bystander or the Culprit of Right-Sided Infective Endocarditis?

BACKGROUND AND CASE SUMMARY: A 46-year-old woman with intravenous heroin use presented with fever, respiratory symptoms, and methicillin-susceptible Staphylococcus aureus bacteremia. Thoracic computed tomography demonstrated multiple septic emboli. Transthoracic echocardiography revealed severe tricuspid regurgitation without vegetations. Transesophageal echocardiography (TEE) discovered a vegetation on the Chiari network and tricuspid leaflet perforation. She was successfully treated with antibiotics. Follow-up TEE showed resolution of the vegetation.

DISCUSSION: This case highlights the Chiari network as an uncommon but clinically relevant substrate for right-sided infective endocarditis in high-risk patients.

TAKE-HOME MESSAGE: In patients with risk factors for right-sided infective endocarditis with apparently no valvular vegetation on transthoracic echocardiography, the Chiari network and Eustachian valve should be evaluated with TEE.