CARDIOMYOPATHY OF GLYCOGEN-STORAGE-DISEASE TYPE-III

To identify the severity of cardiac involvement in glycogen storage di sease type III (GSDIII), and its relation to skeletal muscle involveme nt and age, 23 patients were studied. The median age was 10 years. Ech ocardiography, electrocardiography, and creatine phosphokinase (CK) le vels were used to assess cardiac and skeletal muscle involvement. Sept al and left ventricular posterior wall measurements were compared with normal data. Shortening fraction was derived from left ventricular ca vity dimensions. In some patients the echocardiogram resembled that of hypertrophic cardiomyopathy. Thirteen of 20 electrocardiograms (ECG) were abnormal. Eleven patients had septal and/or posterior wall thickn ess >95% confidence limits (CL). Despite this, cardiac symptoms were u ncommon. The CK levels were not directly associated with cardiac abnor malities. Older patients (>20 years) had more abnormal measurements of posterior wall thickness than did younger ones (<20 years). This find ing, albeit in a cross-sectional series, suggests progressive myocardi al involvement with age despite the absence of symptoms.