CARDIAC INVOLVEMENT IN NEUROMUSCULAR DISO RDERS

Many neuromuscular disorders involve the heart, occasionally with over t clinical disease. Muscular dystrophies (dystrophinopathies, Limb gir dle muscular dystrophy, Emery-Dreyfuss muscular dystrophy, Steinert's myotonic dystrophy), congenital myopathies, inflammatory myopathies an d metabolic diseases (glycogenosis, periodic paralysis, mitochondrial diseases) may produce dilated or hypertrophic cardiomyopathy and heart rhythm or conduction disturbances. Furthermore the heart is commonly involved in some hereditary and degenerative diseases (Friedreich's at axia and Kugelberg-Welander syndrome) and acquired (Guillain-Barre syn drome) or inherited (Refsum's disease and Charcot-Marie-Tooth syndrome ) polyneuropathies. A cardiologist's high clinical suspicion and a sim ple but systematic skeletal muscle and peripheral nerve investigation, including muscle enzymes quantification, neurophysiological study and muscle biopsy, are necessary for an accurate diagnosis. In selected p atients, more sophisticated biochemical and genetic analysis will be n ecessary. In most cases, endomyocardial biopsy is not essential for th e diagnosis.