Cardiac morbidity and mortality due to Chagas' disease: prospective electrocardiographic study of a Brazilian community.

Abstract

The evolution of Chagas' cardiomyopathy is poorly understood. We therefore examined the development of cardiac lesions in a rural Brazilian community for a period of 7 years. Initially, 42% of 1017 residents were seropositive for infection with Trypanosoma cruzi. Age-specific infection rates indicated that most had become infected before the age of 20 years. On follow-up, it appeared that those persons who developed cardiac lesions did so soon after infection, since the incidence of right bundle branch block and other ventricular conduction defects (VCDs) was also highest before age 20 years. The progressive nature of these lesions was demonstrated by frequent development of additional electrocardiographic abnormalities and high mortality among infected adults with VCDs. In contrast, mortality was low and approximately the same for seropositive and seronegative adults under 60 years who had normal electrocardiograms. Electrocardiography during the early asymptomatic stage of infection was able to distinguish persons with potentially lethal cardiac lesions from those with a benign prognosis.

Mechanical cardiac remodeling and new-onset atrial fibrillation in long-term follow-up of subjects with chronic Chagas' disease

“…The systemic infection is generally acquired at an early age (6,7) by vector transmission, although an acute form of parasitic transmission has been increasingly reported in affected countries (8), and may represent a noteworthy healthcare-related problem in Europe and the United States due to migration (9). Its insidious and asymptomatic course, ranging from 10 to 30 years, and eventual advance to myocardial dysfunction, occurring in up to 30% of infected subjects, represents a marker of unfavorable prognosis for cardiovascular morbidity and mortality (10)(11)(12)(13).…”

Evolução clínica a longo prazo, correlacionando a presença de bloqueios da condução intraventricular em pacientes chagásicos e não chagásicos assintomáticos

“…No caso do bloqueio completo do ramo esquerdo (BCRE), esses estudos apontaram que sua prevalência é menor, situando-se entre 2 a 5 %. O acompanhamento desses indivíduos tem revelado o aparecimento, também de bloqueios atrioventriculares, bem como de insuficiência cardíaca, e taxas significativas de mortalidade cardíaca, a qual deve-se principalmente à morte súbita 23 29 39 .…”

O inquérito eletrocardiográfico

“…Esta maior prevalência de alterações eletrocardiográficas nos indivíduos chagásicos quando comparados com os não-chagásicos, é corroborada por outros autores [39][40][41][42] . No Estado do Rio Grande do Sul, a prevalência das alterações eletrocardiográficas nos pacientes com soro reagentes foi de 29,7%, enquanto entre os controles foi de 19,8% (Tabela 4).…”