The use of endomyocardial biopsy in a serious cardiac abnormality associated with polymyositis: a case report.

Life-threatening cardiac abnormalities in polymyositis (PM) patients may result from myocardial inflammation, fibrosis, or another disease process. Few procedures have reliably identified the pathologic basis for these abnormalities. We report a patient with PM, severe congestive cardiomyopathy, and life-threatening ventricular arrhythmias in whom an endomyocardial biopsy was done. The histopathological findings of fibrosis without inflammation, which were confirmed at autopsy, facilitated the decision to treat the patient symptomatically without intensification of antiinflammatory therapy. Endomyocardial biopsy may be a useful technique to determine the exact nature of serious cardiac abnormalities in PM patients so that appropriate therapy may be given.