ELECTROCARDIOGRAPHIC AND ELECTROPHYSIOLOG IC FINDINGS IN PATIENTS WITH MYOTONIC-DYSTROPHY

Myotonic dystrophy is associated with diffuse cardiac conduction distu rbances. Seven consecutive patients, all asymptomatic with respect to cardiac abnormalities, were investigated by means of ECG, Holter monit oring, and invasive electrophysiologic studies (EPS). During Holter mo nitoring, no abnormalities were found in any patient, except for one p atient who showed single monomorphic VEBs. During EPS three patients s howed conduction disturbances in the AV-node (AVN) as well as in the H is-Purkinje-system (HPS) in another three patients. Except for two pat ients ventricular vulnerability was normal during programmed ventricul ar stimulation. A considerable number of asymptomatic patients with my otonic dystrophy reveals AVN- and HPS-conduction disturbances as shown during EPS.