Isolated rheumatic carditis, a disease in search of diagnostic criteria.

We report a case of acute dilated cardiomyopathy with histologic proof of inflammatory myocarditis. Although immunosuppressive therapy seemed to induce the resolution of the inflammatory infiltrate, it had no effect on the clinical course. The diagnosis of isolated rheumatic carditis was considered because of the finding of a very high antistreptolysin O titre and lack of evidence for either viral disease, infection with group C and G streptococci or other causes of spuriously high titres of anti-streptolysin O. In view of our conclusion longterm chemoprophylaxis was instituted.