Radionuclide angiocardiographic analysis of myocardial function in myotonic muscular dystrophy

Using radionuclide angiocardiography, we studied cardiac function in 10 men with myotonic muscular dystrophy who had no cardiac symptoms and were less than 50 years of age, comparing resting and exercise performance of the heart. Nine of 10 patients had an abnormality of myocardial function. The interaction of exercise-induced cardiomyopathy with conduction system abnormalities may be important in sudden cardiac dysfunction in patients with myotonic dystrophy.