Cardiac involvement in myotonic muscular dystrophy (Steinert's disease): A prospective study of 25 patients

• Published in: The American journal of cardiology Vol. 54; no. 8; pp. 1074 - 1081
• Main Authors: Perloff, Joseph K., Stevenson, William G., Roberts, Nigel K., Cabeen, William, Weiss, James
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01.11.1984; Elsevier
• Subjects: Adult; Aged; Arrhythmias, Cardiac - diagnostic imaging; Arrhythmias, Cardiac - physiopathology; Biological and medical sciences; Diseases of striated muscles. Neuromuscular diseases; Echocardiography; Electrocardiography; Female; Heart - diagnostic imaging; Heart - physiopathology; Heart Conduction System - diagnostic imaging; Heart Conduction System - physiopathology; Humans; Male; Medical sciences; Middle Aged; Mitral Valve Prolapse - diagnostic imaging; Mitral Valve Prolapse - physiopathology; Myotonic Dystrophy - diagnostic imaging; Myotonic Dystrophy - physiopathology; Neurology; Prospective Studies; Radionuclide Imaging; Technetium; Heart failure; Nervous system diseases; Myotonic dystrophy; Arrhythmia; Myotonia; Heart disease; Cardiovascular disease
• ISSN: 0002-9149; 1879-1913
• DOI: 10.1016/S0002-9149(84)80147-2

The presence, degree and frequency of disorders of cardiac conduction and rhythm and of regional or global myocardial dystrophy or myotonia have not previously been studied prospectively and systematically in the same population of patients with myotonic dystrophy. Accordingly, 25 adults with classic Steinert's disease underwent electrocardiography, 24-hour ambulatory electrocardiography, vectorcardiography, chest x-rays, echocardiography, electrophysiologic studies, and technetium-99m angiography. Clinically important cardiac manifestations of myotonic dystrophy reside in specialized tissues rather than in myocardium. Involvement is relatively specific, primarily assigned to the His-Purkinje system. The cardiac muscle disorder takes the form of dystrophy rather than myotonia, and is not selective, appearing with approximately equal distribution in all 4 chambers. Myocardial dystrophy seldom results in clinically overt ventricular failure, but may be responsible for atrial and ventricular arrhythmias. Since myotonic dystrophy is genetically transmitted, a primary biochemical defect has been proposed with complete expression of the gene toward striated muscle tissue, whether skeletal or cardiac. Specialized cardiac tissue and myocardium have close, if not identical, embryologic origins, so it is not surprising that the genetic marker affects both. Cardiac involvement is therefore an integral part of myotonic dystrophy, targeting particularly the infranodal conduction system, to a lesser extent the sinus node, and still less specifically, the myocardium.