Exercise electrocardiogram tests in manual workers with and without antibodies to Trypanosoma cruzi: a population-based study

Abstract

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.

Vagal dysfunction and the pathogenesis of chronic Chagas disease

“…Decreased HRV merely indicates that the physiologic parasympathetic fluctuations are diminished [10,11]. Since most chagasic patients are manual workers [12] with normal heart rate responses to exercise and basal heart rates inversely related to the degree of physical fitness, it is possible that Ribeiro indirectly suggest saturation due to enhanced parasympathetic acitivy [3,13]; whereas, Guzetti's [6] results during standing and handgrip exercises indicate the presence of a differential effect of these two maneuvers, on the cardiac parasympathetic system of patients and controls [14]. Cardiac vagal modulation would decrease in the latter and persist in the former.…”

Vagal dysfunction and the pathogenesis of chronic Chagas disease

“…Decreased HRV merely indicates that the physiologic parasympathetic fluctuations are diminished [10,11]. Since most chagasic patients are manual workers [12] with normal heart rate responses to exercise and basal heart rates inversely related to the degree of physical fitness, it is possible that Ribeiro's [1] results indirectly suggest saturation due to enhanced parasympathetic acitivy [3,13]; whereas, Guzetti's [6] results during standing and handgrip exercises indicate the presence of a differential effect of these two maneuvers, on the cardiac parasympathetic system of patients and controls [14]. Cardiac vagal modulation would decrease in the latter and persist in the former.…”

Avaliação de possíveis fatores de risco para a infecção pelo Trypanosoma cruzi em crianças: estudo caso-controle em area rural do estado de Goiás

“…cruzi conseqüente à efetividade do programa de controle de vetores em alguns municípios do Brasil, particularmente nos Estados de São Paulo (Souza et al, 1984 (Zicker et al, 1990c;Zicker et al, 1990e 350.…”