Vasculitis masquerading as aortic valve endocarditis.

Small vessel vasculitis and endocarditis can both present with multisystem involvement and may present a diagnostic dilemma. Renal and cardiac involvement is common in small vessel vasculitis and rarely small vessel vasculitis may cause heart block. When a patient presents with diffuse symptoms, deteriorating renal function, and heart block, endocarditis and vasculitis should be included in the differential diagnosis. The case is discussed of a man with a history of aortic valve endocarditis who presented again with similar symptoms, deteriorating renal function, and heart block. There was no evidence of aortic valve endocarditis with abscess formation. A renal biopsy confirmed small vessel vasculitis and the patient responded promptly to immunosuppressive treatment. Correct diagnosis is essential in such cases, as immunosuppression in true endocarditis can be catastrophic. In this case, with the correct diagnosis, immunosuppression proved life saving and prevented erroneous aortic valve surgery.