[Intractable infective endocarditis associated with supraaortic stenosis in Williams syndrome: a case report].

A 17-year-old man with supravalvular aortic stenosis associated with Williams syndrome was admitted to our hospital for intensive treatment for intractable infective endocarditis. The patient had a history of percutaneous balloon valvuloplasty for aortic stenosis in 1992. He was well until late in 1999, when he had a high temperature after dental work-up. The diagnosis was infective endocarditis but antibiotic therapy was not effective. He was transferred to our clinic. Transthoracic echocardiography demonstrated bicuspid aortic valve, supraaortic stenosis, mitral valve prolapse with severe regurgitation and scattered vegetations on the anterior mitral and aortic valves. In addition, transesophageal echocardiography showed innumerable mobile vegetations located from Valsalva's sinus to the descending aorta. Aortic root and arch replacement with a homograft and mitral valve replacement with an artificial valve were successfully performed to eliminate the infective endocarditis. In the present patient, the flow jet across the supraaortic stenosis seemed to cause a predisposition to severe endocarditis.