Atrial fibrillation/flutter in myopathies.

With improved screening of patients with primary and secondary myopathies and more comprehensive investigations it turns out that an increasing number of patients with myopathies develops cardiac disease (cardiac involvement), before or after onset of the neuromuscular abnormalities. Cardiac involvement in myopathies manifests within the myocardium or the cardiac conduction system with impulse generation or conduction disturbances. An increasingly recognized rhythm abnormality in these patients is atrial fibrillation/flutter (AFI/AFL), which carries an increased risk for stroke embolism and represents an absolute indication for oral anticoagulation (OAC). Primary myopathies, in which AFI/AFL has been described so far include dystrophinopathies, Emery-Dreifuss muscular dystrophy, facio-scapulo-humeral muscular dystrophy, limb girdle muscular dystrophies, congenital myopathies, myofibrillar myopathies, myotonic dystrophies, glycogenoses, mitochondrial disorders, Barth syndrome, McLeod syndrome, and non-specific myopathies. Secondary myopathies, in which AFI/AFL has been described comprise polymyositis, dermatomyositis, colchicine-induced myopathy, and hyperthyroid myopathy. Myopathies most commonly associated with AFI/AFL are myotonic dystrophy and Emery-Dreifuss muscular dystrophy. Information about the frequency of stroke/embolism in these patients is rudimentary but there are indications that it is not increased in these patients. Only a few patients with AFI/AFL receive OAC to prevent from stroke/embolism. Patients with myopathy and AFI/AFL require thorough surveillance. If additional cardiovascular risk factors develop, OAC should be considered as in patients with other causes of AFI/AFL.