Diverse Cardiac Phenotype of Becker Muscular Dystrophy: Under-Recognized Subclinical Cardiomyopathy Due to Partial Dystrophin Deficiency in a Contemporary Era

AbstractBecker muscular dystrophy (BMD) is an X-linked recessive disorder responsible for mild skeletal muscle involvement and variable degree of cardiomyopathy. The characteristics of cardiac phenotype of BMD in childhood remain elusive. Clinical manifestations, genotype, serum biomarkers, and echocardiogram were retrospectively reviewed in BMD patients. Cardiac phenotype was classified into acute progressive (AP), chronic persistent (CP), and latent (L) groups based upon symptoms and echocardiographic findings. Twenty-five BMD patients were studied over 9.5  ± 2.5 years. Sixteen patients presented initially with variable degree of muscle weakness whereas 9 were asymptomatic. Three patients developed medically refractory heart failure by age 18 with progressive dilated cardiomyopathy (DCM) (AP). Six patients developed mild to moderate left ventric ular (LV) systolic dysfunction with LV dilatation but remained asymptomatic (CP). Although 16 patients continued to show normal LV function (L), they demonstrated variable degrees of skeletal muscle involvement. The AP groups presented with significantly larger LV size and LV mass index (LVMI) at th e initial encounter than groups CP or L, suggesting early myocardial remodeling predicts rapid disease progression. None presented with atrophic myocardial phenotype commonly observed in Duchenne muscular dystrophy (DMD). Wide availability of genetic testing has changed the scope of clinical present ation of BMD. Cardiomyopathy in...
Source: Pediatric Cardiology - Category: Cardiology Source Type: research