[Comparison of histologic changes in Chagas' cardiomyopathy and dilated cardiomyopathy].

In this study the histopathologic features of Chagas' disease and idiopathic dilated cardiomyopathy were compared in 38 patients with congestive heart failure, classes II or III. Biopsy specimens were obtained with the Stanford model needle for right ventricle. Twenty-two patients presented non-chagasic dilated cardiomyopathy, and 16 were carriers of Chagas' disease. Twenty-three were male and 15 were female; their ages varied 18 and 49 years (mean 35.5). Fibrosis was slightly more frequently and intense in Chagas' disease than in dilated cardiomyopathy. Myocarditis aspect also was more frequent in Chagas' disease than in dilated cardiomyopathy (62.4% vs. 50%), with all cases showing a chronic form; acute myocarditis was observed only in dilated myocardiopathy. These differences, however, did not reach statistical significance. In conclusion, the presence of fibrosis, hypertrophy and moderate to severe degrees of chronic inflammatory infiltrate are suggestive of but not pathognomonic of Chagas' disease. On the other hand, dilated myocardiopathies are more frequently associated with less fibrosis or hypertrophy and the presence of mild degree of inflammatory infiltrate. The arrangement of this inflammatory infiltrate tends to be diffuse in dilated cardiomyopathy and in chagasic myocarditis it is multifocal, very similar to the histopathological aspect found in myocardial rejections episodes of transplanted hearts.