Inflammatory Diseases of the Heart and Pericardium: Dilated Cardiomyopathy and Myocarditis

The incidence of dilated cardiomyopathy in children is low and variable. The Pediatric Cardiomyopathy Registry found an incidence of 1.13 cases per 100,000 children for all forms of cardiomyopathy [3]. The registry data also noted a regional difference—1.44 cases per 100,000 in New England and 0.98 cases per 100,000 in the central Southwest. The incidence of dilated cardiomyopathy was higher in certain groups, namely, African Americans, infants, and males. In a prospective study of cardiomyopathy in children in one medium-sized state (population 3.5 million), the number of newly diagnosed cases each year (over a 12 year period) ranged from 0 to 10 cases per year (H. Wiles, unpublished data). In the past, the largest single class of dilated cardiomyopathy was idiopathic, with the largest identifi ed cause being myocarditis (usually viral) [4]. Now there is recognition that many cases are familial or genetic in origin, perhaps as many as 30% of cases [5]. Although dilated cardiomyopathy more frequently occurs in families or in those with a genetic mutation, the exact cause or structural abnormality is still not known. Recognition of familial occurrence or genetic markers does not yet provide any meaningful therapeutic options.