[Conduction defects and arrhythmias in peripheral myopathies]

The association between peripheral myopathies and cardiac complications is well established. However, until recently, the clinical and genetic variability of these pathologies limited our ability to recognise individual risk of complications, particularly in the more rare pathologies. Advances have been made in the understanding of the progression, in the physiopathology of molecular deficits and cardiac complications of the different types of muscular dystrophy. This has partially helped to identify the risk of cardiac complications. The commonest condition, Steinert's disease, is associated with a high incidence of atrioventricular block and atrial arrhythmias. Prophylactic implantation of a dual chamber pacemaker with diagnostic functions may be envisaged when the HV interval is greater than 70 ms, on endocavitary electrophysiological investigations. In other patients, follow-up by standard ECG and/or amplified averaged ECG and Holter monitoring is essential. The natural history of Duchenne and Becker muscular dystrophies and the Emery Dreifuss dystrophy have been better described in the last few years. Recommendations have been proposed for the cardiological follow-up of these patients. Empiric recommendations of the same type have been proposed for patients with shoulder and girdle myopathies and propositions for their management have also been made, the pertinence of which is still being evaluated. Our understanding of the incidence, the type, the physiopathology and molecular biology of the various peripheral myopathies and their cardiac complications has advanced considerably in recent years. This has led to the elaboration of new recommendations for diagnostic and therapeutic strategies in these patients.