1398 Myocarditis in Kawasaki Syndrome A Minor Villain ?

T wenty-two years have passed since the original description by Tomisaku Kawasaki of the syndrome that now bears his name.' The syndrome is now known to occur throughout the world. The true annual incidence in the United States is unknown, but overall incidence is estimated to be 4.5-9.5 per 100,000 children under 5 years of age in nonepidemic years, whereas during epidemics, the incidence increases several fold.2 In contrast, the incidence of acute rheumatic fever has been as low as 1 per 100,000 inhabitants of all ages; however, geographic pockets have reported sporadically higher incidences in recent years. The incidence of viral myocarditis is difficult to assess. As of 1989, Kawasaki syndrome appears to be one of the leading causes of acquired heart disease in children. Despite an intensive international search, the etiologic agent of Kawasaki syndrome has eluded researchers. Various biologic and nonbiologic agents have been proposed and then discarded one by one for lack of independent confirmation. Coronary artery complications have been considered a major villain in Kawasaki syndrome. Deaths have been almost exclusively the result of myocardial infarction. However, the mortality rate has