ELECTROCARDIOGRAPHIC ALTERATIONS IN CHRONICALLY TRYPANOSOMA CRUZI-INFECTED PERSONS EXPOSED TO CARDIOVASCULAR FACTORS

Methods: We analyzed the potential influence that associated risk fact ors (ARF), such as smoking, alcoholism, overweight, and hypertension, could have on the establishment of chronic chagasic cardiomyopathy (CC ). The sample was comprised of 124 individuals, 69 males and 55 female s (mean age +/- SD, 41 +/- 9.5 years), who were born in en demic areas of Northern Argentina and migrated further to Rosario City, an area w here autochthonous cases of Chagas' disease have never been registered . Assessments included the following: clinical examination to discard previous cardiomyopathies; search for the presence of ARF according to standard criteria; specific serology; frontal chest X-ray, and 12-lea d resting electrocardiogram (ECG). Subjects were classified on the bas is of their serological status and presence of ARF into four groups: T c(+)ARF(+) T. cruzi-infected persons with ARF (n = 41); Tc(-)ARF(+)ser onegativity in presence of ARF (n = 27); Tc(+)ARF(-) individuals showi ng positive serology that lacked ARF (n = 27), and Tc(-)ARF(-) seroneg ative individuals having no ARF (n = 29). Results: Except for a higher female/male ratio in groups presenting no ARF (p<0.02), no statistica l differences as to age, length of residence in endemicity areas (LR), and ARF distribution were recorded among groups. Forty-one persons pr esented abnormal ECG tracings, distributed thus: Tc(+)ARF(+), 18/41; T c(-)ARF(+), 14/27, Tc(+)ARF(-), 14/27, and Tc(-)ARF, 4/29 (p <0.01, in relation to the latter group). Subjects from the Tc(+)ARF(+), Tc(-)AR F(+), and Tc(+)ARF(-) groups had 4.89-, 6.7-, and 6.7-fold increases, respectively, if having an abnormal ECG when compared with Tc(-)ARF(-) individuals. Comparisons on the frequency of abnormal ECG between ser opositives carrying ARF or not yielded a non-significant odds ratio, b e it estimated as crude, or after adjusting for sex, age, and LR in mu ltivariate analysis. Conclusions: Presence of ARF was not associated w ith an increasing risk of cardiac affectation in chronically T. cruzi- infected persons, but resulted in chagasic-compatible ECG abnormalitie s in those seronegative individuals.