Abstract
Introduction: Detection of systemic embolization is important for treating patients with infective endocarditis (IE). Subclinical small emboli, many of which might occur behind the overt embolization, will be detected as a microembolic signal (MES) with transcranial Doppler (TCD).
Case report: A 54-year-old male with fever and impaired consciousness was admitted with suspected encephalopathy. His medical history included bioprosthetic aortic valve replacement performed 3 years before admission. Although IE was considered as differential diagnosis, transthoracic echocardiography and contrast-enhanced CT scan did not reveal the presence of lesions. According to the modified Duke criteria, his case was classified as “rejected IE.” However, TCD revealed four MESs in the left middle cerebral artery, and IE was reconsidered. Transesophageal echocardiography revealed a 14-mm mobile vegetation on the prosthetic valve. Although early surgery was planned, CT revealed small subarachnoid hemorrhages in the left cerebral hemisphere. The risk of systemic embolization was considered high; therefore, valve replacement was performed at day 6 after admission. After 1 month, the patient was discharged without sequelae.
Conclusions: MESs may be useful as a marker for subclinical embolization in patients with IE. Further studies should assess the potential of TCD for the diagnosis and risk stratification of IE.
