Muscular dystrophy is an inherited condition associated with progressive muscle weakness, and loss of muscle mass. Several different types of muscular dystrophy associated with distinct genetic changes have now been identified. In addition to muscle weakness, patients with muscular dystrophy can be affected by heart disease.
Myotonic muscular dystrophy (MMD) also referred to as myotonic dystrophy (MD) is the most common form of adult-onset muscular dystrophy and is divided into two genetic variants, type 1 and type 2. Patients with myotonic muscular dystrophy usually start to feel muscle loss and weakness in adolescence or adulthood. Other associated conditions include diabetes, cataracts, abnormal mental function, gland problems, joint problems, difficulty swallowing, lack of energy and myotonia (slow muscle relaxation after use).
Importantly, patients with myotonic dystrophy are also at risk for cardiac disease. Heart arrhythmias (slow or fast heart rates) can be an early manifestation and if untreated can lead to episodic loss of consciousness (called syncope) or worse sudden death. At Johns Hopkins Hospital, patients with myotonic muscular dystrophy are typically followed by a neurologist and cardiac electrophysiologist, thus optimizing the early recognition and treatment of cardiac involvement and symptoms.