Myotonic dystrophy and cardiac disorders

Myotonic dystrophy (MD) is a multisystem disease affecting numerous organs and systems. Cardiac involvement is frequent. Sudden death, due to fatal ca rdiac rhythm and conduction disturbances occurs in 30% of patients with MD, The aim of this study was to assess the possibilities and methods of early detection of myocardial and conduction system disturbances. ECG, 24-hr Hol ter monitoring, echocardiography and electrophysiologic studies of the cond uction system (electrophysiologic study) were carried out in 45 patients. A nalysis of late ventricular potentials was done in 36 patients. Genetic stu dies revealed multiplication of CTG triplets in all patients. Cardiological abnormalities were detected in 89% of our patients, Disturbances of intrav entricular conduction with prolongation of HV interval were most frequent ( 72%), Electrophysiologic study was the most sensitive method for detecting heart involvement in MD (positive findings in 87% patients), Abnormal findi ngs were also discovered by Holter monitoring (64%), ECG (58%), analysis of late ventricular potentials (55%) and by echocardiography in 46% patients, The results of this study indicate a high rate of cardiac involvement in M D.