[Electrocardiography and electrophysiologic findings in patients with myotonic muscular dystrophy]

Myotonic dystrophy is associated with diffuse cardiac conduction disturbances. Seven consecutive patients, all asymptomatic with respect to cardiac abnormalities, were investigated by means of ECG, Holter monitoring, and invasive electrophysiologic studies (EPS). During Holter monitoring, no abnormalities were found in any patient, except for one patient who showed single monomorphic VEBs. During EPS three patients showed conduction disturbances in the AV-node (AVN) as well as in the His-Purkinje-system (HPS) in another three patients. Except for two patients ventricular vulnerability was normal during programmed ventricular stimulation. A considerable number of asymptomatic patients with myotonic dystrophy reveals AVN- and HPS-conduction disturbances as shown during EPS.