RESUMO
Blood pressure, heart rate and electrocardiographic responses to exercise were compared in a group of 125 subjects with antibodies to Trypanosoma cruzi and in 153 seronegative subjects, randomly selected from persons with no evidence of heart disease in a resting electrocardiogram during a cross-sectional survey among apparently healthy manual workers. The mean heart rates and diastolic and systolic blood pressures of those in each group did not differ statistically at different phases of the exercise test and there was no evidence of a difference in physical fitness between those in the 2 groups. An abnormal test was recorded in 26.2% of seropositive, and in 16.1% of seronegative, subjects (odds ratio adjusted for age, sex and body mass index [OR] = 2.0, 95% confidence interval [95% CI] = 1.1-3.8). No significant difference was observed between the 2 groups in the occurrence of hypertensive response to exercise (6.4% among seropositives and 5.9% among seronegatives), ST depression greater than 1 mm (0.8% and 2.0%), supraventricular premature beats (4.8% and 2.6%) or conduction defects (0.8% and 1.3%). Complex ventricular premature beats were recorded more often in seropositive subjects (12.8% and 3.9%; OR = 3.7, 95% CI = 1.4-9.8, P less than 0.01). The risk of an abnormal test increased with age in both groups. A history of cardiovascular symptoms, gender and body mass was not associated with the risk of an abnormal response in the test. The findings suggest that exercise testing might be a routine procedure when subjects with antibodies to T. cruzi are being assessed for participation in potentially high risk activities, such as heavy manual work.
Assuntos
Cardiomiopatia Chagásica/fisiopatologia , Eletrocardiografia , Teste de Esforço , Coração/fisiopatologia , Adulto , Animais , Anticorpos Antiprotozoários/análise , Pressão Sanguínea/fisiologia , Cardiomiopatia Chagásica/diagnóstico , Doença de Chagas/imunologia , Doença de Chagas/fisiopatologia , Estudos Transversais , Feminino , Frequência Cardíaca/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Trypanosoma cruzi/imunologia , Avaliação da Capacidade de TrabalhoRESUMO
A case-control study was conducted to examine whether physical activity, sibling history of heart disease (HHD), and length of residence in an area endemic for Chagas' disease were associated with the risk of developing Chagas' cardiopathy. Two hundred forty-seven cases of Chagas' heart disease and 345 seropositive subjects with normal ECG (controls) were selected in a population survey in Goiânia, Brazil. Prevalence ratios for exposure variables were estimated for cases in relation to controls and for subgroups of seropositives with selected ECG abnormalities in relation to controls. Increasing age and male sex were consistently and significantly related to an increased risk of ECG abnormalities. HHD was significantly associated with ECG alterations in 3 of the 5 comparison subgroups (any ECG alteration, right bundle branch block, and left anterior hemiblock). No association was found between length of residence in an area endemic, physical activity, and ECG abnormalities. A sample of 529 seronegative subjects were also examined and the interaction between exposure variables and seropositivity was tested to assess whether the associations found were specific for seropositives. Males were at greater risk of any ECG alteration and left anterior hemiblock in relation to females if they were seropositive. An increasing risk of ventricular premature beats with age was clearer for seropositive than for seronegative subjects. Subjects with HHD were at an increased risk of ECG abnormalities and this was greater in those with a positive serological test (P less than 0.05). The findings suggest a possible geographical clustering or a familial aggregation of cases of Chagas' heart disease.
Assuntos
Cardiomiopatia Chagásica/etiologia , Cardiopatias/parasitologia , Adulto , Brasil , Estudos de Casos e Controles , Cardiomiopatia Chagásica/epidemiologia , Eletrocardiografia , Família , Feminino , Cardiopatias/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Aptidão Física , Recidiva , Fatores de RiscoRESUMO
In a cross sectional survey of the prevalence of Trypanosoma cruzi infection among urban unskilled workers in Goiânia, Brazil, blood samples from 6222 manual workers from seven institutions were examined for anti-Trypanosoma cruzi antibodies by immunofluorescence, ELISA and haemagglutination tests. ECGs were performed and a clinical history was taken from 624 seropositive and a random sample of 529 seronegative subjects. Abnormal ECGs were found in 15.1% of individuals without Trypanosoma cruzi antibodies and in 44.4% of those with antibodies (p less than 0.001). In general, cardiovascular symptoms reported were not associated with seropositivity nor with ECG alterations but dizziness and dyspnoea were more often reported among those with an abnormal tracing (p less than 0.01). The prevalence of ECG abnormalities increased with age in both groups but was higher among those seropositive in all age groups. An odds ratio of 2.0 (95% Cl 1.2-3.1) and 2.9 (95% Cl 1.5-6.3) of ECG abnormalities, for each decade of life, was estimated for seropositive and seronegative subjects, respectively. Relative risks (based on the odds ratios) for various specific ECG abnormalities, comparing seropositive to seronegative individuals, were calculated after adjustment for age, sex and institution. The odds ratio for complete right bundle branch block was 49.9 (95% CL 12.2-203.4); for left anterior hemiblock was 4.1 (2.8-6.0); for large Q/QS waves was 4.2 (2.4-7.3) and for first degree A-V block was 8.5 (2.6-28.1).