[The electrocardiographic survey]. / O inquérito eletrocardiográfico.

In order to investigate the prevalence of chagasic heart disease in Brazil, a national electrocardiographic survey was carried out from 1977 to 1981. A total of 5,347 electrocardiograms (ECG) were performed and paired by age and gender. The results obtained in relation with the autochthonous cases, were distributed by Brazilian states, as follows: Rio Grande do Sul (1,078), Minas Gerais (760), Bahia (612), Paraná (400), Paraiba (340), Piauí (218), Sergipe (216), Goiás (176), Pernambuco (170), Ceará (136) and Alagoas 134. The higher proportions of altered ECGs among seropositive individuals were found in the States of Goiás (63.6%), Minas Gerais (57.6%), Ceará (57.3%), Paraná (54.5%), Piauí (53.2%) and Paraiba (52.3%). Among the control individuals, these proportions were respectively 25%, 25.7%, 25%, 12.5%, 22.9% and 26.5%. A significant statistical difference of altered ECGs between positive and negative individuals was verified in all the States, with a single exception (Alagoas). The estimation of the gradient showed to be higher in Paraná State (42%), followed by Goiás (38.6%), Ceará (32.3%), Minas Gerais (31.9%), Piauí (30.3%), Paraíba (25.8%), Pernambuco (22.3%), Bahia (18.9%), Sergipe (16.7%), Rio Grande do Sul (9.9%) and Alagoas (7.5%). Concerning the distribution of the electrocardiographical alterations found in the eleven states, the main alterations find among the seropositive group were: ventricular extrasystoles, complete right bundle branch block, left anterior fascicular block, the association of complete right bundle branch block with left anterior fascicular block and primary alterations of the ST segment and of the T wave. Furthermore, these ECG alterations were more prevalent in the group of infected individuals.

O inquérito eletrocardiográfico / The electrocardiographic survey

Entre 1977 e 1981, foi realizado um inquérito eletrocardiográfico nacional tendo por objetivo avaliar a prevalência da cardiomiopatia chagásica no Brasil. Foram feitos 5.347 eletrocardiogramas. Após o pareamento dos indivíduos, segundo a idade e gênero, a distribuição dos eletrocardiogramas dos autóctones, em cada estado, ficou assim constituída: Rio Grande do Sul (1.078), Minas Gerais (760), Bahia (612), Paraná (400), Paraíba (340), Piauí (218), Sergipe (216), Goiás (176), Pernambuco (170), Ceará (136) e Alagoas (134). Os maiores percentuais de alterações eletrocardiográficas entre os indivíduos com soros reagentes foram encontrados nos Estados de Goiás (63,6 por cento), Minas Gerais (57,6 por cento), Ceará (57,3 por cento), Paraná (54,5 por cento), Piauí (53,2 por cento) e Paraíba (52,3 por cento). Entre os controles, nestes estados, a prevalência das alterações eletrocardiográficas foi de 25 por cento, 25,7 por cento, 25 por cento, 12,5 por cento, 22,9 por cento e 26,5 por cento respectivamente. Observou-se diferença estatisticamente significativa em relação à prevalência das alterações eletrocardiográficas, entre os indivíduos soro reagentes e os não reagentes, em todos os estados, exceção feita para o de Alagoas. O cálculo do gradiente mostrou-se maior no Estado do Paraná (42 por cento), seguido por Goiás (38,6 por cento), Ceará (32,3 por cento) Minas Gerais (31,9 por cento), Piauí (30,3 por cento), Paraíba (25,8 por cento), Pernambuco (22,3 por cento), Bahia (18,9 por cento), Sergipe (16,7 por cento), Rio Grande do Sul (9,9 por cento) e Alagoas (7,5 por cento). Em relação à distribuição das alterações eletrocardiográficas encontradas, nos onze estados analisados, verificou-se que as extrassístoles ventriculares, o bloqueio de grau avançado do ramo direito, o bloqueio da divisão ântero-superior do ramo esquerdo, a associação do bloqueio de grau avançado do ramo direito com o bloqueio da divisão ântero-superior do ramo esquerdo e alterações primárias do segmento ST e da onda T, mostraram diferença estatisticamente significativa, entre os indivíduos com sororreagentes e os não reagentes Além disto, estas alterações eletrocardiográficas foram as de maior prevalência no grupo dos indivíduos chagásicos.

In order to investigate the prevalence of chagasic heart disease in Brazil, a national electrocardiographic survey was carried out from 1977 to 1981. A total of 5,347 electrocardiograms (ECG) were performed and paired by age and gender. The results obtained in relation with the autochthonous cases, were distributed by Brazilian states, as follows: Rio Grande do Sul (1,078), Minas Gerais (760), Bahia (612), Paraná (400), Paraiba (340), Piauí (218), Sergipe (216), Goiás (176), Pernambuco (170), Ceará (136) and Alagoas 134. The higher proportions of altered ECGs among seropositive individuals were found in the States of Goiás (63.6 percent), Minas Gerais (57.6 percent), Ceará (57.3 percent), Paraná (54.5 percent), Piauí (53.2 percent) and Paraiba (52.3 percent). Among the control individuals, these proportions were respectively 25 percent, 25.7 percent, 25 percent, 12.5 percent, 22.9 percent and 26.5 percent. A significant statistical difference of altered ECGs between positive and negative individuals was verified in all the States, with a single exception (Alagoas). The estimation of the gradient showed to be higher in Paraná State (42 percent), followed by Goiás (38.6 percent), Ceará (32.3 percent), Minas Gerais (31.9 percent), Piauí (30.3 percent), Paraíba (25.8 percent), Pernambuco (22.3 percent), Bahia (18.9 percent), Sergipe (16.7 percent), Rio Grande do Sul (9.9 percent) and Alagoas (7.5 percent). Concerning the distribution of the electrocardiographical alterations found in the eleven states, the main alterations find among the seropositive group were: ventricular extrasystoles, complete right bundle branch block, left anterior fascicular block, the association of complete right bundle branch block with left anterior fascicular block and primary alterations of the ST segment and of the T wave. Furthermore, these ECG alterations were more prevalent in the group of infected individuals.

Mortality indicators among chronic Chagas patients living in an endemic area.

BACKGROUND: Chagas disease is a serious social-medical problem in Latin American countries because of its high incidence, morbidity and mortality. Our aim was to identify, from demographic, personal history, clinical and electrocardiographic variables, those that might have independent prognostic value regarding mortality, among a population of chronic Chagas patients from a single endemic area where vector transmission has been halted. METHODS AND RESULTS: Over a mean of 18.5 years, we followed up a prospective cohort of 120 individuals with chronic Chagas disease. Twenty dichotomous variables with prognostic potential for chronic Chagas disease patients were initially evaluated using the Cox model (univariable analysis), to calculate the proportional mortality risk from all causes, cardiovascular causes and sudden death, relative to each variable separately. Of these, 12 variables presenting statistical significance (p<0.05) were included in a multivariable model to determine which of them would have independent prognostic value regarding mortality. Over the follow-up, there were 42 deaths. Eight variables were proven to be independent prognostic factors for mortality, in relation to the three types of death analysed: age ≥39 years, black skin colour, high-degree right-branch block, anterosuperior division block of the left branch, high-degree right-branch block associated with anterosuperior division block of the left branch, high-degree left-branch block, polymorphic ventricular extrasystoles and PR interval ≥0.16 s. CONCLUSIONS: The presence on conventional electrocardiograms of polymorphic ventricular extrasystoles or high-degree left-branch block, among a population of chronic Chagas patients, constitutes the most important independent factor for poor prognosis.

[A comparison of three electrocardiogram coding systems for chronic Chagas' disease]. / Estudo comparativo de três códigos para leitura de eletrocardiogramas na doença de Chagas crônica1.

OBJECTIVE: To compare three electrocardiogram coding systems (Buenos Aires, New York Heart Association, and modified Minnesota) for use with Chagas' disease. METHODS: Between January 1976 and December 1978 persons older than 2 years of age living in the town of Agua Comprida, Minas Gerais, Brazil, underwent a patient history, physical examination, conventional electrocardiography, and serology for Chagas' disease. Those records were archived, and in 1999 from this sample, 100 seropositive individuals were matched by sex and age with 100 seronegative controls. The electrocardiograms of these 200 patients were read using the three coding systems. Each system was assessed in terms of its gradient, that is, the difference between the number of abnormalities found in the electrocardiograms of individuals with and without Chagas' disease. RESULTS: The gradient was 7% for the New York Heart Association coding system, 15% for the modified Minnesota system, and 17% for the Buenos Aires one. The ability of the Buenos Aires method to detect electrocardiographic abnormalities was significantly greater in the group with Chagas' disease than in controls (P = 0.012), followed by the modified Minnesota system (P = 0.028) and the New York Heart Association system (P = 0.31). The Buenos Aires method was also easier to use, in terms of both the analysis of electrocardiograms and queries to a database. CONCLUSIONS: Although the Buenos Aires method had advantages over the two other systems, some changes are still needed in it to make it more useful. It would be worth carrying out further studies to evaluate this method with the changes that we have suggested in this study.

Estudo comparativo de três códigos para leitura de eletrocardiogramas na doença de Chagas crônica / A comparison of three electrocardiogram coding systems for chronic Chagas' disease

OBJETIVO: Comparar três códigos de leitura de eletrocardiogramas (Buenos Aires, New York Heart Association e Minnesota adaptado) na doença de Chagas. MÉTODOS: De janeiro de 1976 a dezembro de 1978, a populaçäo maior de 2 anos do Município de Agua Comprida, Estado de Minas Gerais, Brasil, zona endêmica da doença de Chagas, foi submetida a anamnese, exame físico, eletrocardiograma convencional e sorologia para doença de Chagas. Dessa amostra, 100 pacientes soropositivos foram pareados com 100 controles negativos, segundo critérios de sexo e idade. Os eletrocardiogramas dos 200 pacientes foram lidos utilizando cada um dos três códigos. Os códigos foram comparados em termos de seu gradiente (diferença entre o número de alteraçöes encontradas nos eletrocardiogramas de chagásicos e de näo chagásicos). RESULTADOS: O gradiente foi de 7 por cento para a nomenclatura da New York Heart Association, 15 por cento para o código de Minnesota adaptado e 17 por cento para o método de Buenos Aires. A capacidade de detecçäo de alteraçöes eletrocardiográficas do método de Buenos Aires foi significativamente maior no grupo de chagásicos do que no grupo dos näo chagásicos (P = 0,012). O método de Buenos Aires sobressaiu ainda pela sua mais fácil utilizaçäo, tanto no que se refere à análise dos eletrocardiogramas, como também às consultas ao banco de dados. CONCLUSÖES: Embora o método de Buenos Aires tenha apresentado vantagens em relaçäo aos outros métodos, ainda säo necessárias algumas alteraçöes para tornar seu uso mais adequado. Seria de interesse a realizaçäo de outros estudos avaliando o uso do método com as alteraçöes sugeridas no presente trabalho