Cardiac involvement in carriers of Duchenne and Becker muscular dystrophy

A cross-sectional study in a cohort of DNA proven carriers of Duchenne (DMD ) and Becker (BMD) muscular dystrophy was undertaken with the following obj ectives: (1) to estimate the frequency of electrocardiographic (ECG) and ec hocardiographic abnormalities; (2) to establish the proportion of carriers with dilated cardiomyopathy and (3) to assess possible associations between dilated cardiomyopathy and genotype. One hundred and twenty nine DMD and B MD carriers, aged 18-60 years, were traced through the files of the central register kept at the department of Human Genetics in Leiden. Investigation s included full medical history, physical examination, ECG and two-dimensio nal and M-mode echocardiographic examination. Forty-seven percent had ECG c hanges. Thirty-six percent (DMD 41%, BMD 27%) had at least one abnormality as is usually found in the male patients. Echocardiographic examination was abnormal in 36% (DMD 38%, BMD 34%). Dilated cardiomyopathy was found in se ven DMD carriers (8%), and in none of BMD carriers. In addition, 18% had le ft ventricle dilatation (DMD 19%, BMD 16%). Only 38 % had a completely norm al investigation of the heart. We found no association between genotype and cardiac manifestations. Our study underlines that cardiac involvement is p art of the dystrophinopathies. Carriers should be told about the increased risk of this complication when asking genetic advice. It also implicates th at a complete cardiological evaluation should be performed at least once in all carriers. If left ventricle dilatation or dilated cardiomyopathy is pr esent a yearly follow up is needed, in order to start timely therapy. (C) 1 999 Elsevier Science Ireland Ltd. All rights reserved.