EFFECT OF CHAGAS-DISEASE ON ARTERIAL BLOOD

One hundred and fifteen chagasic patients were studied, who had positive Machado-Guerreiro complement fixation test and positive epidemiologic history. The mean age of the group was 39 ± 12 years and the male-female relation was 1 1. Only 29 had heart failure. The chagasic population studied was compared with a previous study where we got the blood pressure curve of the general population in relation to age and sex (Medicina 31:393-415, 1971). The mean values of the systolic and diastolic pressures of chagasic men and women were significantly lower (P < 0.05), in each of the studied decades, than those of the general population, with a few exceptions. The mean female systolic pressure did not surpass the mean male systolic pressure at the age of 30, as usually happens in the general population. When the chagasic patients were subdivided into those with or without heart failure, it was clear that there were no differences between these two groups, and that patients without heart failure had significantly lower pressures than the general population. When the chagasic population was subdivided into ponderal groups, the differences between the chagasic and general population increased. The blood pressure-weight relationship observed in the general population was not present in our chagasic patients. There were fewer hypertensive individuals among chagasic patients than in the general population. The determining reasons for these observations are unknown and possible mechanisms are being discussed. © 1979.