[Pathological anatomy of the heart in myopathies and infantile muscular atrophies].

In progressive muscular dystrophy, the heart is always affected and presents characteristic histological lesions: irregular, diffuse and intense rearrangements predominantly in the left ventricle, the septum and conductive tissue, consisting of wide, poorly vascularized fibrous bands, that are destructive but without an inflammatory aspect. The remaining myocardium is dystrophic with degeneration of the fibers (hyalin, atrophic or hypertrophic) with irregular nuclei. Plaques of adipose tissue are found under the epicardium within the heart wall. Sometimes, a fibrous thickening of the intracoronary arteries is observed without modification of the intima, but vascular lesions are not systematically seen. In congenital muscular dystrophy, cardiomyopathy certainly exists, but there is no histological description. Half of the patients suffering from myopathy with intracytoplasmic inclusions also have dystrophic and fibrotic cardiac involvement. Congenital myopathies may have their own specific cardiomyopathy, as in central core myopathy, nemaline (rod) myopathy and especially myotubular myopathy, where involvement is common. Werdnig-Hoffmann disease types I and II do not affect the heart. In contrast, several cases of fibrotic lesions have been described in KugelbergWelander disease.