Cardiac Disease in Muscular Dystrophy
Source: Laforet P, et al. Cardiac involvement in genetically confirmed facioscapulohumeral muscular dystrophy. Neurology 1998;51:1454-1456.
Facioscapulohumeral muscular dystrophy (FSHMD), an autosomal dominant myopathy mapped to the telomeric end of chromosome 4q35, shows almost complete penetrance, with a variable rate of progression, but uniform evolution in all patients. Often asymmetric, it begins in the facial and shoulder girdle muscles, later spreads to abdominal, foot extensor, and pelvic girdle muscles, and rarely is associated with symptomatic hearing loss and retinopathy (Padberg GW, et al. Muscle Nerve 1998;Suppl 7;S25). Cardiac involvement has usually been ascribed to unrelated, coincidental illness but this may now require reconsideration (Griggs RC, et al. Evaluation and Treatment of Myopathies. CNS Series. Philadelphia: FA Davis Company; 1995:122-126). Among 100 clinically and molecularly defined FSHMD patients, five demonstrated significant cardiac rhythm abnormalities unrelated to myopathic disease or cardiovascular risk factors. This includes supraventricular arrhythmia (n = 3), two of which had conduction defects, and one each with arrythmogenic right ventricular cardiomyopathy, hitherto unreported in myopathic patients, severe atrioventricular block requiring pacemaker insertion, and supraventricular arrhythmia with palpitations. Five percent of FSHMD patients appear to be at risk for coincident cardiac arrythmias. EKG study and follow-up is warranted.