Dilated cardiomyopathy associated with Friedreich's ataxia.

Friedreich's ataxia (FA) is a progressive, spinocerebellar, degenerative, neuromuscular disease that is frequently associated with hypertrophic cardiomyopathy as part of the clinical illness. Hypertrophic cardiomyopathy associated with FA can be seen with or without obstruction to the left ventricle outflow tract. We present the postmortem findings in a case of FA with dilated (congestive) cardiomyopathy. At autopsy, the heart was enlarged with all four chambers dilated; no ventricular hypertrophy or aortic outflow obstruction was present. Microscopic sections of myocardium revealed myocyte hypertrophy, atrophy, and focal interstitial fibrosis. Findings of dilated cardiomyopathy at necropsy supported the antemortem clinical impression. Although FA has been reported to be associated rarely with dilated cardiomyopathy, postmortem documentation of dilated cardiomyopathy with FA has not been shown previously, to our knowledge. The mechanism of either form of myocardial disease in patients with FA is presently speculative.