The heart in muscular dystrophy: an electrocardiographic and ultrasound study of 20 patients.

Twenty patients with different types of muscular dystrophy (MD) were included in a cross-sectional study by means of electrocardiography and ultrasound cardiography. A manifest cardiomyopathy was detected in 8 patients; a latent cardiomyopathy was found in 4. A hypertrophic cardiomyopathy was especially frequent in facioscapulohumeral MD, a congestive cardiomyopathy in Becker-Kiener MD. The ECG showed a reduction in the QT interval and frequent block formers in the X-chromosomal inherited forms and the trunc-girdle form. Bradycardia and a prolonged QT interval were frequent in myotonic dystrophy and facioscapulohumeral MD. Signs of cardiac infarction in the ECG were most frequent in the trunc-girdle forms. A high cardiac output per minute in conjunction with increased left ventricular volume was frequent in Becker-Kiener and Landouzy MD. A left ventricular dysfunction with reduced ejection was characteristic of myotonic dystrophy and trunc-girdle MD. A mitral valve prolapse was more frequent with increasing severity of the muscle disease and was particularly frequent in myotonic dystrophic and Landouzy MD. The cardiac output per minute and the stroke volume were significantly lower (P less than or equal to 0.03) where a mitral valve prolapse was present.