Electrocardiographic characteristics in a population with high rates of seropositivity for Trypanosoma cruzi infection.

This study was conducted in Posse, a rural community in Goiàs, Brazil. Persons were recruited into the study through house-to-house sampling of all houses in the sampled area. Blood samples were collected for seropositivity assessments for Trypanosoma cruzi and an electrocardiogram was assessed using a portable system. The results demonstrate significant differences between seropositive and seronegative persons for electrocardiographic (ECG)-derived traits. Seropositive persons had substantially longer QRS and QT intervals than seronegative persons. The PR interval was significantly different between seropositive and seronegative persons. Conduction abnormalities were observed more frequently in seropositive than seronegative persons. Right bundle branch block, an ECG abnormality typical of Chagas disease, was observed in 15% of seropositive persons compared with less than 1% of seronegative persons. Results indicate that T. cruzi infection and subsequent Chagas disease will continue to be major health problems for the foreseeable future in this typical rural area of Brazil.