Cardiomyopathy in glycogen-storage disease type III: clinical and echographic study of 18 patients.

Cardiac examinations were performed on 18 patients with glycogen-storage disease (GSD) type III. Clinical examination was always normal and the electrocardiograms revealed nonspecific data. Similarly, serum muscular enzyme activities were not useful in indicating the presence of cardiomyopathy. Echocardiographic evidence of myocardiopathy was found in five of the 16 children studied (mean age, 9.5 years). Echocardiographic parameters remained stable during the follow-up period (at least 3 years). The other 11 children had no echocardiographic evidence of cardiomyopathy. No relationship was found between peripheral myopathy and cardiomyopathy. All patients with GSD type III should be regularly investigated by echocardiography in respect of their cardiac muscle status.