 Our group has investigated the role and Se effect on infection by T. cruzi. By evaluating plasma Se levels in 170 chagasic patients, we discovered that the frequency of subjects with Se levels lower than normal was significantly higher in those with severe cardiopathy. Moreover, in this pioneering research, we found a positive correlation between Se levels and the LVEF, indicating that normal Se levels pave the way for efficient cardiac function. Later, we investigated if nutritional deficiency of this trace element interfered with the development of cardiopathy and the susceptibility to experimental T. cruzi infection. In that study, we found 100 of mortality in Se deficient mice, while in the selenium adequate groups only 20 of the male and no female died even at 40 dpi. In addition, parasitemia levels of infected mice were not altered by Se deficiency, suggesting that the high susceptibility at the acute phase was not due to the parasite load. We later investigated if Se treatment could minimize the course of T. cruzi infection or the myocarditis in mice. We verified that the concentration of 4 ppm Se did not alter the resistance to infection but was able in preventing the increase of CK-MB levels in infected mice, indicating that Se helps to protect the heart from inflammatory damage driven by T. cruzi infection. 