[Anatomo-clinical and epidemiologic study of Chagas disease]

Chagas' disease is a chronic form caused by a parasite, the Trypanosoma Cruzi, endemic of Latin America. The Trypanosoma Cruzi is transmitted by hematophageous bugs, particularly in dilapidated rural areas. Three phases of the disease can be distinguished: 1) acute phase, with high tissue and blood parasitic involvement; 2) undetermined phase, in which the diagnosis requires sophisticated clinical investigations; 3) chronic phase (10-30 years following the infection), characterized particularly by cardiac disease manifestations. The present 120 patients were subdivided into four groups: 1) 43 asymptomatic serum-positive subjects; 2) 25 serum-positive patients with electrocardiographic abnormalities; 3) 14 serum-positive patients with cardiomegaly; 4) 38 with classic chagasic cardiopathy. Comparative studies among these four groups were carried out employing Holter monitoring (24h), ergometric and phonomechanographic tests, M-mode and bidimensional echography and radionuclide ventriculography. A significant difference between the first 3 groups and, respectively, the fourth group (p < 0.001) was found. Deadly-risk (p < 0.001) manifestation were pointed out, such as a third tone, right bundle branch block with left anterior hemiblock and left ventricle's dilation. Autoptic controls were performed and in 4 patients the myocardial biopsy showed C3 and IgG deposition in capillaries and myocardial fibers, at electron microscopic examination, some thickening of capillary and myocytic basal membrane, interstitial collagen proliferation, besides non-specific myocellular abnormalities were detected.