Infected left atrial myxoma with bacteremia simulating infective endocarditis.

A 58-year-old man had intermittent fever of eight months' duration following a dental extraction. There were no abnormal cardiac auscultatory findings. Multiple blood cultures yielded Streptococcus mutans. Treatment for infective endocarditis was initiated; however, an echocardiogram suggested the presence of a left atrial myxoma. The diagnosis was confirmed by angiography and the infected tumor was removed successfully. Differentiating features between left atrial myxoma and mitral valve endocarditis may not be obvious clinically, and bacteremia does not preclude atrial myxoma as a diagnostic possibility. We therefore suggest that all cases of infective endocarditis be evaluated by echocardiography to elucidate lesions such as large vegetations or left atrial myxoma, both of which may require urgent operative intervention.