Successful steroid therapy for heart failure due to myocarditis associated with primary biliary cirrhosis.

This report concerns a 65-year-old woman with primary biliary cirrhosis (PBC) featuring high titers of M2 antimitochondrial antibody who developed intractable heart failure (HF). Although the etiology is unclear, involvement of skeletal muscles has been reported with PBC as a result of mitochondrial damage from the autoimmune process. In this case, histopathological examination and (18)F-fluorodeoxy glucose-positron emission tomography imaging revealed myocarditis concomitant with myositis. The patient showed favourable response to high-dose corticosteroid administration. To the best of our knowledge, this is the first case of HF with myocarditis and polymyositis associated with asymptomatic PBC who was successfully treated with prednisolone.