Analysis of Three-Dimensional Scar Architecture and Conducting Channels by High-Resolution Contrast-Enhanced Cardiac Magnetic Resonance Imaging in Chagas Heart Disease

ABSTRACT Background: We aimed to describe the morphology of the border zone of viable myocardium surrounded by scarring in patients with Chagas heart disease and study their association with clinical events. Methods: Adult patients with Chagas heart disease (n=22; 55% females; 65.5 years, SD 10.1) were included. Patients underwent high-resolution contrast-enhanced cardiac magnetic resonance using myocardial delayed enhancement with postprocessing analysis to identify the core scar area and border zone channels number, mass, and length. The association between border zone channel parameters and the combined end-point (cardiovascular mortality or internal cardiac defibrillator implantation) was tested by multivariable Cox proportional hazard regression analyses. The significance level was set at 0.05. Data are presented as the mean (standard deviation [SD]) or median (interquartile range). Results: A total of 44 border zone channels (1[1-3] per patient) were identified. The border zone channel mass per patient was 1.25 (0.48-4.39) g, and the extension in layers of the border zone channels per patient was 2.4 (1.0-4.25). Most border zone channels were identified in the midwall location. Six patients presented the studied end-point during a mean follow-up of 4.9 years (SD 1.6). Border zone channel extension in layers was associated with the studied end-point independent from left ventricular ejection fraction or fibrosis mass (HR=2.03; 95% CI 1.15-3.60). Conclusions: High-resolution contrast-enhanced cardiac magnetic resonance can identify border zone channels in patients with Chagas heart disease. Moreover, border zone channel extension was independently associated with clinical events.

Prevalence of Chagas heart disease in dilated cardiomyopathy / Prevalencia de cardiopatía chagásica en la miocardiopatía dilatada

Abstract Objectives: The main objective is to determine the prevalence of American trypanosomiasis in patients with dilated cardiomyopathy in a tertiary hospital in western Mexico. Methods: From January 1991 to February 2016, 387 consecutive patients with a confirmed diagnosis of dilated cardiomyopathy were included in the study. Cases with ventricular dilatation secondary to ischemic heart disease, valvular heart disease, hypertension, lung disease, pericardial disease, or congenital heart disease were excluded from the study. Diagnosis was made detecting antibodies against Trypanosoma cruzi with two different methods or parasite in blood. Results: Were included 387 patients with dilated cardiomyopathy, Chagas cardiomyopathy was confirmed in 6.9%, two patients in the acute phase (in one, suspected transfusion transmission was detected). Most patients were born in rural areas. About 96.2% showed congestive heart failure, only one patient with apical left ventricular aneurysm manifested palpitations. About 66% with right bundle branch block, left anterior fascicular block, or the association of both, in 14.8%, non-sustained ventricular tachycardia was found. Conclusions: Chagas cardiomyopathy is common in México, mainly in people who were born or lived during childhood in rural areas. It is a common cause of heart failure. Chagas’ heart disease should be suspected in patients receiving a blood transfusion, even without another epidemiological history.

Resumen Objetivo: El objetivo principal del estudio es conocer la prevalencia de tripanosomiasis americana en pacientes con cardiomiopatía dilatada, en un hospital de concentración en el occidente de México. Métodos: Desde enero de 1991 a febrero de 2016 se incluyeron 387 pacientes consecutivos con diagnóstico de cardiomiopatía dilatada, se excluyeron los casos con dilatación ventricular secundaria a cardiopatía isquémica, valvulopatías, hipertensión arterial sistémica, enfermedad pulmonar, enfermedad pericárdica o cardiopatías congénitas. El diagnóstico se realizó mediante la detección de anticuerpos anti-tripanosoma cruzi con 2 métodos positivos diferentes o con la detección del parásito en sangre. Resultados: Se incluyeron 387 paciente con cardiomiopatía dilatada, en el 6.9% se confirmó cardiopatía chagásica; dos pacientes en fase aguda (uno con sospecha de transmisión transfusional). La mayoría de los pacientes provenían de zonas rurales. El 96.2% de los casos presentó insuficiencia cardiaca congestiva, un paciente con aneurisma apical del ventrículo izquierdo solo manifestó palpitaciones. El 66% presentó bloqueo de la rama derecha del haz de His, hemibloqueo anterior izquierdo o la asociación de ambos, en el 14.8% se encontró taquicardia ventricular no sostenida. Conclusiones: La cardiopatía chagásica es frecuente en nuestro medio, principalmente en personas que nacieron o vivieron durante la infancia en áreas rurales. Es causa común de insuficiencia cardiaca. La cardiomiopatía chagásica debe sospecharse en pacientes que reciben transfusión sanguínea, incluso sin otros antecedentes epidemiológicos

Chronic Chagas cardiomyopathy: a review of the main pathogenic mechanisms and the efficacy of aetiological treatment following the BENznidazole Evaluation for Interrupting Trypanosomiasis (BENEFIT) trial

Chagas cardiomyopathy is the most frequent and most severe manifestation of chronic Chagas disease, and is one of the leading causes of morbidity and death in Latin America. Although the pathogenesis of Chagas cardiomyopathy is incompletely understood, it may involve several mechanisms, including parasite-dependent myocardial damage, immune-mediated myocardial injury (induced by the parasite itself and by self-antigens), and microvascular and neurogenic disturbances. In the past three decades, a consensus has emerged that parasite persistence is crucial to the development and progression of Chagas cardiomyopathy. In this context, antiparasitic treatment in the chronic phase of Chagas disease could prevent complications related to the disease. However, according to the results of the BENEFIT trial, benznidazole seems to have no benefit for arresting disease progression in patients with chronic Chagas cardiomyopathy. In this review, we give an update on the main pathogenic mechanisms of Chagas disease, and re-examine and discuss the results of the BENEFIT trial, together with its limitations and implications.

Relação entre Fibrose e Arritmias Ventriculares na Cardiopatia Chagásica sem Disfunção Ventricular / Relationship between Fibrosis and Ventricular Arrhythmias in Chagas Heart Disease Without Ventricular Dysfunction

Fundamento: Pacientes com doença de Chagas com alteração segmentar apresentam pior prognóstico independentemente da fração de ejeção ventricular esquerda. A ressonância magnética cardíaca é atualmente o melhor método para detecção de alteração segmentar e para avaliação de fibrose miocárdica. Objetivo: Quantificar a fibrose, por meio do realce tardio, pela ressonância magnética cardíaca, em pacientes com doença de Chagas com fração de ejeção ventricular esquerda preservada ou minimamente comprometida (> 45%) e detectar padrões de dependência entre fibrose, alteração segmentar e fração de ejeção ventricular esquerda na presença de arritmia ventricular. Métodos: Foram realizados eletrocardiograma, teste ergométrico, Holter e ressonância magnética cardíaca em 61 pacientes, separados em três grupos: (1) eletrocardiograma normal e ressonância magnética cardíaca sem alteração segmentar; (2) eletrocardiograma alterado e ressonância magnética cardíaca sem alteração segmentar; e (3) ressonância magnética cardíaca com alteração segmentar independentemente de alteração no eletrocardiograma. Resultados: O número de pacientes com arritmia ventricular em relação ao número total de pacientes em cada grupo, a porcentagem de fibrose e a fração de ejeção ventricular esquerda foram, respectivamente: no primeiro grupo, 4/26, 0,74% e 74,34%; no segundo grupo, 4/16, 3,96% e 68,5%; e no terceiro grupo, 11/19, 14,07% e 55,59%. Arritmia ventricular foi encontrada em 31,1% dos pacientes. Aqueles com e sem arritmia ventricular apresentaram fração de ejeção ventricular esquerda média de 59,87% ...

Background: Patients with Chagas disease and segmental wall motion abnormality (SWMA) have worse prognosis independent of left ventricular ejection fraction (LVEF). Cardiac magnetic resonance (CMR) is currently the best method to detect SWMA and to assess fibrosis. Objective: To quantify fibrosis by using late gadolinium enhancement CMR in patients with Chagas disease and preserved or minimally impaired ventricular function (> 45%), and to detect patterns of dependence between fibrosis, SWMA and LVEF in the presence of ventricular arrhythmia. Methods: Electrocardiogram, treadmill exercise test, Holter and CMR were carried out in 61 patients, who were divided into three groups as follows: (1) normal electrocardiogram and CMR without SWMA; (2) abnormal electrocardiogram and CMR without SWMA; (3) CMR with SWMA independently of electrocardiogram. Results: The number of patients with ventricular arrhythmia in relation to the total of patients, the percentage of fibrosis, and the LVEF were, respectively: Group 1, 4/26, 0.74% and 74.34%; Group 2, 4/16, 3.96% and 68.5%; and Group 3, 11/19, 14.07% and 55.59%. Ventricular arrhythmia was found in 31.1% of the patients. Those with and without ventricular arrhythmia had mean LVEF of 59.87% and 70.18%, respectively, and fibrosis percentage of 11.03% and 3.01%, respectively. Of the variables SWMA, groups, age, LVEF and fibrosis, only the latter was significant for the presence of ventricular arrhythmia, with a cutoff point of 11.78% for fibrosis mass (p < 0.001). Conclusion: Even in patients with Chagas disease and preserved or minimally impaired ventricular function, electrical instability can be present. Regarding the presence of ventricular arrhythmia, fibrosis is the most important variable, its amount being proportional to the complexity of the groups. .

Morbidity of Chagas heart disease in the microregion of Rio Negro, Amazonian Brazil: a case-control study

A case-control study on the morbidity of Chagas heart disease was carried out in the municipality of Barcelos in the microregion of the Rio Negro, state of Amazonas. One hundred and six individuals, who were serologically positive for Trypanosoma cruzi infection, as confirmed by at least two techniques with different principles, were matched according to age and sex with an equal number of seronegative individuals. The cases and controls were evaluated using an epidemiological questionnaire and clinical, electrocardiograph and echocardiograph examinations. In the seroepidemiological evaluation, 62% of the interviewees recognised triatomines and most of them confirmed that they had seen these insects in the piassava plantations of the riverside communities of the Negro River tributaries. Of the seropositive patients, 25.8% affirmed that they had been stung by the triatomines and 11.7% denied having been stung. The principal clinical manifestations of the seropositive individuals were palpitations, chest pain and dyspnoea upon effort. Cardiac auscultation revealed extrasystoles, bradycardia and systolic murmurs. The electrocardiographic alterations were ventricular extrasystoles, left and right bundle branch block, atrioventricular block and primary T wave alterations. The echocardiogram was altered in 22.6% of the seropositive individuals and in 8.5% of the seronegative individuals.

Utility of a novel risk score for prediction of ventricular tachycardia and cardiac death in chronic Chagas disease - the SEARCH-RIO study

The SEARCH-RIO study prospectively investigated electrocardiogram (ECG)-derived variables in chronic Chagas disease (CCD) as predictors of cardiac death and new onset ventricular tachycardia (VT). Cardiac arrhythmia is a major cause of death in CCD, and electrical markers may play a significant role in risk stratification. One hundred clinically stable outpatients with CCD were enrolled in this study. They initially underwent a 12-lead resting ECG, signal-averaged ECG, and 24-h ambulatory ECG. Abnormal Q-waves, filtered QRS duration, intraventricular electrical transients (IVET), 24-h standard deviation of normal RR intervals (SDNN), and VT were assessed. Echocardiograms assessed left ventricular ejection fraction. Predictors of cardiac death and new onset VT were identified in a Cox proportional hazard model. During a mean follow-up of 95.3 months, 36 patients had adverse events: 22 new onset VT (mean±SD, 18.4±4‰/year) and 20 deaths (26.4±1.8‰/year). In multivariate analysis, only Q-wave (hazard ratio, HR=6.7; P<0.001), VT (HR=5.3; P<0.001), SDNN<100 ms (HR=4.0; P=0.006), and IVET+ (HR=3.0; P=0.04) were independent predictors of the composite endpoint of cardiac death and new onset VT. A prognostic score was developed by weighting points proportional to beta coefficients and summing-up: Q-wave=2; VT=2; SDNN<100 ms=1; IVET+=1. Receiver operating characteristic curve analysis optimized the cutoff value at >1. In 10,000 bootstraps, the C-statistic of this novel score was non-inferior to a previously validated (Rassi) score (0.89±0.03 and 0.80±0.05, respectively; test for non-inferiority: P<0.001). In CCD, surface ECG-derived variables are predictors of cardiac death and new onset VT.

Effects of an exercise program on blood pressure in patients with treated hypertension and chronic Chagas' heart disease / Efeitos de um programa de exercícios na pressão arterial de pacientes com hipertensão controlada e cardiopatia chagásica crônica

INTRODUCTION: Previous studies describe an imbalance of the autonomic nervous system in Chagas' disease causing increased sympathetic activity, which could influence the genesis of hypertension. However, patients undergoing regular physical exercise could counteract this condition, considering that exercise causes physiological responses through autonomic and hemodynamic changes that positively affect the cardiovascular system. This study aimed to evaluate the effects of an exercise program on blood pressure in hypertensive patients with chronic Chagas' heart disease. METHODS: We recruited 17 patients to a 24-week regular exercise program and used ambulatory blood pressure monitoring before and after training. We determined the differences in the systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean blood pressure (MBP) from the beginning to the end of the study. RESULTS: The blood pressures were evaluated in general and during periods of wakefulness and sleep, respectively: SBP (p = 0.34; 0.23; 0.85), DBP (p = 0.46; 0.44; 0.94) and MBP (p = 0.41; 0.30; 0.97). CONCLUSIONS: There was no statistically significant change in blood pressure after the 24-week exercise program; however, we concluded that physical training is safe for patients with chronic Chagas' disease, with no incidence of increase in blood pressure.

INTRODUÇÃO: Estudos prévios descrevem um desequilíbrio do sistema nervoso autônomo na doença de Chagas causando maior atividade simpática, o que poderia influenciar na gênese da hipertensão arterial. No entanto, pacientes submetidos a exercícios físicos regulares poderiam contrapor esta condição, visto que o exercício provoca respostas fisiológicas através de adaptações autonômicas e hemodinâmicas que influenciam positivamente o sistema cardiovascular. O presente estudo se propõe a avaliar os efeitos da reabilitação cardíaca sobre a pressão arterial em pacientes hipertensos com cardiopatia chagásica crônica. MÉTODOS: Foram recrutados 17 pacientes submetidos a um programa regular de exercícios durante 24 semanas, sendo utilizado monitorização ambulatorial da pressão arterial (MAPA) antes e após o treinamento. Foi descrita a diferença da pressão arterial sistólica (PAS), pressão arterial diastólica (PAD) e pressão arterial média (PAM) do início ao fim estudo. RESULTADOS: As pressões foram avaliadas de forma geral e nos períodos de vigília e sono, respectivamente: PAS (p=0,34; 0,23; 0,85), PAD (p=0,46; 0,44; 0,94) e PAM (p=0,41; 0,30; 0,97). CONCLUSÕES: Não houve diferença estatisticamente significativa na variação da pressão arterial após o período de reabilitação cardíaca de 24 semanas, no entanto, evidenciamos que o treinamento físico é seguro em pacientes com cardiopatia chagásica crônica, não ocorrendo aumento da pressão arterial.

Effects of an exercise program on the functional capacity of patients with chronic Chagas' heart disease, evaluated by cardiopulmonary testing / Efeitos de um programa de exercícios sobre a capacidade funcional de pacientes com cardiopatia chagásica crônica, avaliados por teste cardiopulmonar

INTRODUCTION: Despite all efforts to restrict its transmission, Chagas' disease remains a severe public health problem in Latin America, affecting 8-12 million individuals. Chronic Chagas' heart disease, the chief factor in the high mortality rate associated with the illness, affects more than half a million Brazilians. Its evolution may result in severe heart failure associated with loss of functional capacity and quality of life, with important social and medical/labor consequences. Many studies have shown the beneficial effect of regular exercise on cardiac patients, but few of them have focused on chronic Chagas' heart disease. METHODS: This study evaluated the effects of an exercise program on the functional capacity of patients with chronic Chagas' disease who were treated in outpatient clinics at the Evandro Chagas Institute of Clinical Research and the National Institute of Cardiology, Rio de Janeiro, Brazil. The exercises were performed 3 times a week for 1 h (30 min of aerobic activity and 30 min of resistance exercises and extension) over 6 months in 2010. Functional capacity was evaluated by comparing the direct measurement of the O2 uptake volume (VO2) obtained by a cardiopulmonary exercise test before and after the program (p < 0.05). RESULTS: Eighteen patients (13 females) were followed, with minimum and maximum ages of 30 and 72 years, respectively. We observed an average increase of VO2peak > 10% (p = 0.01949). CONCLUSIONS: The results suggest a statistically significant improvement in functional capacity with regular exercise of the right intensity.

INTRODUÇÃO: Mesmo com todos os esforços para interrupção de sua transmissão, a doença de Chagas permanece como grave problema de saúde pública na América Latina, onde atinge entre 8 e 12 milhões de indivíduos. A cardiopatia chagásica crônica, principal responsável pela elevada morbimortalidade da doença, chega a acometer mais de meio milhão de brasileiros. Sua evolução atinge estágios graves de insuficiência cardíaca com perda de capacidade funcional e qualidade de vida, com grande impacto social e médico-trabalhista. Muitos estudos demonstram o resultado benéfico da prática regular de exercícios em cardiopatas, porém, há escassez de investigações em cardiopatia chagásica. MÉTODOS: O presente estudo avaliou efeitos de um programa de exercícios sobre a capacidade funcional de dezoito pacientes (13 mulheres) com cardiopatia chagásica crônica, com idade entre 30 e 72 anos, atendidos nos ambulatórios do Instituto de Pesquisa Clínica Evandro Chagas e do Instituto Nacional de Cardiologia, na cidade do Rio de Janeiro. Os exercícios foram executados 3 vezes por semana, durante 1 hora (30 minutos de atividade aeróbica e 30 minutos de exercícios contra-resistência e alongamentos), ao longo de 6 meses, no ano de 2010. A avaliação da capacidade funcional foi realizada pela comparação da medida direta do VO2 obtido pelo Teste de Exercício Cardiopulmonar, antes e depois do programa. Para análise estatística foram utilizados testes T de Student pareado e de Wilcoxon. RESULTADOS: Os resultados mostram aumento médio do VO2pico acima de 10%(p=0,01949). CONCLUSÕES: Os resultados sugerem melhora significativa da capacidade funcional com prática regular de exercícios na população amostral.

Insights into the clinical and functional significance of cardiac autonomic dysfunction in Chagas disease / Considerações sobre o significado clínico-funcional da disfunção autonômica cardíaca na doença de Chagas

INTRODUCTION: Exclusive or associated lesions in various structures of the autonomic nervous system occur in the chronic forms of Chagas disease. In the indeterminate form, the lesions are absent or mild, whereas in the exclusive or combined heart and digestive disease forms, they are often more pronounced. Depending on their severity these lesions can result mainly in cardiac parasympathetic dysfunction but also in sympathetic dysfunction of variable degrees. Despite the key autonomic effect on cardiovascular functioning, the pathophysiological and clinical significance of the cardiac autonomic dysfunction in Chagas disease remains unknown. METHODS: Review of data on the cardiac autonomic dysfunction in Chagas disease and their potential consequences, and considerations supporting the possible relationship between this disturbance and general or cardiovascular clinical and functional adverse outcomes. RESULTS: We hypothesise that possible consequences that cardiac dysautonomia might variably occasion or predispose in Chagas disease include: transient or sustained arrhythmias, sudden cardiac death, adverse overall and cardiovascular prognosis with enhanced morbidity and mortality, an inability of the cardiovascular system to adjust to functional demands and/or respond to internal or external stimuli by adjusting heart rate and other hemodynamic variables, and immunomodulatory and cognitive disturbances. CONCLUSIONS: Impaired cardiac autonomic modulation in Chagas disease might not be a mere epiphenomenon without significance. Indirect evidences point for a likely important role of this alteration as a primary predisposing or triggering cause or mediator favouring the development of subtle or evident secondary cardiovascular functional disturbances and clinical consequences, and influencing adverse outcomes.

INTRODUÇÃO: Lesões isoladas ou combinadas de várias estruturas do sistema nervoso autônomo ocorrem nas formas crônicas da doença de Chagas. Na forma indeterminada, as lesões são discretas e podem estar até ausentes, enquanto nas formas cardíaca e digestória exclusivas ou combinadas elas são comumente mais pronunciadas. Na dependência da sua maior ou menor severidade, estas lesões podem resultar em variáveis graus de disfunção parassimpática e/ou simpática, principalmente a primeira. Apesar da crítica influência autonômica sobre o funcionamento cardiovascular, o significado fisiopatológico e clínico, notadamente em longo prazo, da disfunção autonômica cardíaca permanece desconhecido na doença de Chagas. MÉTODOS: Revisão sobre a disfunção autonômica cardíaca na doença de Chagas e suas potenciais consequências, como base para considerações acerca da possível relação entre este distúrbio e desfechos clínicos e funcionais globais e cardiovasculares desfavoráveis. RESULTADOS: Os potenciais desfechos que a disautonomia cardíaca pode variavelmente determinar ou predispor na doença de Chagas incluem: arritmias transitórias ou sustentadas, morte súbita, mal prognóstico global e cardiovascular, morbi-mortalidade aumentada, deficiente adaptação cardiovascular a demandas funcionais e/ou em resposta a estímulos internos e externos por meio de ajustes da frequência cardíaca e outras variáveis hemodinâmicas, e distúrbios imunomoduladores e psico-funcionais. CONCLUSÕES: A alteração da modulação autonômica cardíaca na doença de Chagas pode não representar mero epifenômeno sem significado. Evidências indiretas sugerem papel importante desta alteração como fator predisponente ou determinante primário para o desenvolvimento secundário de distúrbios funcionais manifestos ou não e consequências clínicas cardiovasculares, e para a ocorrência de desfechos desfavoráveis.

Paciente com cardiopatia chagásica crônica, esquistossomose hepatoesplênica e síndrome da imunodeficiência adquirida: possível resolução espontânea de trombo no ventrículo direito / Patient with chronic Chagas heart disease, hepatosplenic schistosomiasis and acquired immunodeficency syndrome: possible spontaneous resolution of thrombus in the right ventricle

A presença de trombos nas câmaras cardíacas direitas parece aumentar o risco de morte no tromboembolismo. Entretanto, existe discrepância entre a prevalência de trombos intracavitários cardíacos e evidências clínicas de tromboembolismo. Além disso, as características individuais associadas ao elevado risco de mortalidade não estão bem estabelecidas. Este relato descreve o caso de um paciente portador de esquistossomose mansônica, síndrome da imunodeficiência adquirida (SIDA) e doença de Chagas crônica, apresentando grande trombo no ventrículo direito. A evolução foi favorável, sem complicações tromboembólicas e com provável resolução espontânea do trombo.

The presence of right-sided cardiac thrombi seems to increase the risk of death due to thromboembolic events. There is a discrepancy, however, between the prevalence of cardiac thrombus and clinical thromboembolic events. Besides, the individual characteristics associated with a high risk of mortality have not been established. We present here a case report of a patient with mansonic schistosomiasis and acquired immunodeficiency syndrome and chronic Chagas disease, who presents with a large thrombus in the right ventricle. The patient had uneventful evolution without any thromboembolic complications with resolution of right-ventricle thrombus.

Efeitos de um programa de exercícios sobre a capacidade funcional de pacientes com cardiopatia chagásica crônica / Efects of an exercise program on functional capacity of patients with chronic Chagas' heart disease

Introdução: Mesmo com todos os esforços para interrupção de sua transmissão, a doença de Chagas permanece como grave problema de saúde pública na América Latina, onde atinge entre 8 e 12 milhões de indivíduos. A cardiopatia chagásica crônica, principal responsável pela elevada morbimortalidade da doença, chega a acometer mais de meio milhão de brasileiros. Sua evolução pode atingir estágios graves de insuficiência cardíaca associada à perda de capacidade funcional e qualidade de vida, com grande impacto social e médico-trabalhista. Muitos estudos demonstram o resultado benéfico da prática regular de exercícios em cardiopatas, porém, há escassez de investigações em cardiopatia chagásica. Métodos: O presente estudo avaliou efeitos de um programa de exercícios sobre a capacidade funcional de 18 pacientes (13 mulheres) com cardiopatia chagásica crônica, com idade entre 30 e 72 anos, atendidos nos ambulatórios do Instituto de Pesquisa Clínica Evandro Chagas e do Instituto Nacional de Cardiologia, na cidade do Rio de JaneiroOs exercícios foram executados 3 vezes por semana, durante 1 hora (30 minutos de atividade aeróbica e 30 minutos de exercícios contra-resistência e alongamentos), ao longo de 6 meses, no ano de 2010. A avaliação da capacidade funcional foi realizada pela comparação da medida direta do VO2 obtido pelo Teste de Exercício Cardiopulmonar, antes e depois do programa. Para análise estatística foi utilizado o teste T de Student pareado e de Wilcoxon. Resultados: Os resultados mostram aumento médio do VO2pico acima de 10 porcento (p=0,01949). Conclusões: Os resultados sugerem melhora estatisticamente significativa da capacidade funcional com a prática regular de exercícios na população amostral...

Background: Despite all efforts to interrupt transmission, Chagas disease remains asevere public health problem in Latin America, affecting between 8 and 12 millionindividuals. The main cause for the high mortality of the disease is chronic Chagas'heart disease, which comes to affect more than half a million Brazilians. Its evolutionmay reach severe stages of heart failure associated with loss of functional capacity andquality of life, with enormous social and labor impact. Several studies have shown thebeneficial effect of regular exercise in cardiac patients, but few of them study Chagas'heart disease. Methods: This study evaluated the effects of an exercise program onfunctional capacity of 18 patients (13 women) with chronic Chagas' heart disease, agedbetween 30 and 72 years, treated in outpatient clinics of the Evandro Chagas Institute ofClinical Research and the National Institute of Cardiology in the city of Rio de Janeiro.The exercises were performed three times a week for one hour (30 minutes of aerobicactivity and 30 minutes of resistance exercise and stretching) over 6 months in the year2010. The functional capacity evaluation was performed by comparing directmeasurement of VO2 obtained by Cardiopulmonary Exercise Test before and after theprogram. The t Student and Wilcoxon tests were used to statistical analysis. Results:The results show an average increase in VO2 peak above 10 percent (p = 0.01949).Conclusions: The results suggest statistical significant improvement in functionalcapacity with regular exercise of the sample population...

Chagas heart disease: pathophysiologic mechanisms, prognostic factors and risk stratification

Chagas heart disease (CHD) results from infection with the protozoan parasite Trypanosoma cruzi and is the leading cause of infectious myocarditis worldwide. It poses a substantial public health burden due to high morbidity and mortality. CHD is also the most serious and frequent manifestation of chronic Chagas disease and appears in 20-40% of infected individuals between 10-30 years after the original acute infection. In recent decades, numerous clinical and experimental investigations have shown that a low-grade but incessant parasitism, along with an accompanying immunological response [either parasite-driven (most likely) or autoimmune-mediated], plays an important role in producing myocardial damage in CHD. At the same time, primary neuronal damage and microvascular dysfunction have been described as ancillary pathogenic mechanisms. Conduction system disturbances, atrial and ventricular arrhythmias, congestive heart failure, systemic and pulmonary thromboembolism and sudden cardiac death are the most common clinical manifestations of chronic Chagas cardiomyopathy. Management of CHD aims to relieve symptoms, identify markers of unfavourable prognosis and treat those individuals at increased risk of disease progression or death. This article reviews the pathophysiology of myocardial damage, discusses the value of current risk stratification models and proposes an algorithm to guide mortality risk assessment and therapeutic decision-making in patients with CHD.

Association of HDL cholesterol and triglycerides with mortality in patients with heart failure

It has been demonstrated that there is an association between serum lipoproteins and survival rate in patients with ischemic cardiomyopathy, as well as in patients with non-ischemic causes of heart failure. We tested the hypothesis of an association between serum lipoprotein levels and prognosis in a cohort of outpatients with heart failure, including Chagas' heart disease. The lipid profile of 833 outpatients with heart failure in functional classes III and IV of the New York Heart Association, with a mean age of 46.9 ± 10.6 years, 655 (78.6 percent) men and 178 (21.4 percent) women, was studied from April 1991 to June 2003. The survival rate was estimated by the Kaplan-Meyer's method and the Cox proportional hazards models. Etiology of heart failure was ischemic cardiomyopathy in 171 (21 percent) patients, Chagas' heart disease in 144 (17 percent), hypertensive cardiomyopathy in 136 (16 percent), and other etiologies in 83 (10 percent). In 299 (36 percent) patients, heart failure was ascribed to idiopathic dilated cardiomyopathy. Variables significantly associated with mortality were age (hazard ratio, HR = 1.02; 95 percentCI = 1.01-1.03; P = 0.0074), male gender (HR = 1.77; 95 percentCI = 1.2-2.62; P = 0.004), idiopathic dilated cardiomyopathy (HR = 1.81; 95 percentCI = 1.16-2.82; P = 0.0085), serum triglycerides (HR = 0.97; 95 percentCI = 0.96-0.98; P < 0.0001), and HDL cholesterol (HR = 0.99; 95 percentCI = 0.99-1.0; P = 0.0280). Therefore, higher serum HDL cholesterol and higher serum triglycerides were associated with lower mortality in this cohort of outpatients with heart failure.

Propedêutica cardiológica para avaliação dacardiopatia chagásica na atenção primária / Cardiologic investigation for the evaluation of Chagas' heart disease inthe primary health assistance

Objetivos: Controlando-se a transmissão da doença de Chagas, faz-se necessário investir na prevenção dos agravos de sua cardiopatia crônica. Procurou-se comparar a propedêutica cardiológica acessível na Atenção Primária, com exames mais complexos, na avaliação dos cardiopatas chagásicos. Métodos: Foram analisados os prontuários de 515 pacientes acompanhados no ambulatório do Grupo de Estudos em Doença de Chagas (GEDoCh) - HC / UNICAMP, Campinas,SP, sendo selecionados 52 com registro completo dos exames básicos - avaliação clínica, ECG convencional (ECG) e RX detórax (RX), e ao menos um dos exames complementares: teste de esforço (TE), ecocardiograma (ECO) e eletrocardiografia dinâmica (Holter). Excluíram-se os prontuários com dados incompletos ou de portadores de outras cardiopatias, incluindos edoença arterial coronariana e doença reumática, hipertensão arterial e alcoolismo. Comparamos-se os resultados desses dois tipos de investigação. Resultados: A avaliação clínica, associada ao ECG e RX,mostrou significância quando confrontada com aptidão cardiorrespiratória(ACR) e classe funcional (CF) obtidas no TE(p=0,0062; p=0,0409). Os cardiopatas mais graves apresentaram comprometimento maior da ACR e CF mais baixa, comparando-se aos menos graves. Os demais exames complexos não mostraram associação significativa com a propedêutica cardiológica disponível em nível de Atenção Primária.Conclusão: A propedêutica cardiológica básica permite classificar a cardiopatia chagásica em formas leve ou grave. Entretanto, apenas dois parâmetros obtidos no TE (ACR e CF) mostraram correlação significativa com o exame clínico. De qualquer modo, a propedêutica cardiológica básica é relevantena consideração do nível em que devem ser assistidos os portadores crônicos dessa afecção.(AU)

Objective: The next step after the control of Chagas’ diseasetransmission is the investment in the prevention of the chagasic cardiopathy damage. This study intended to comparethe basic cardiologic investigation with the complex cardiologic investigation in Chagas’ heart disease.Methods: The study evaluated 52 medical records among515 of the chagasic patients from the Ambulatory of the Chagas’Disease Study Group (State University of Campinas, SP). These patients showed complete registration of Clinical Evaluation, ECG, Chest Radiography, and, at least one of the morecomplex exams: Ergometric Test, Echocardiography Evaluation,and Holter. It was excluded those with incomplete data, other cardiac diseases, arterial hypertension, and alcoholism.The results obtained from the two kinds of cardiologic evaluationwere compared. Results: The clinical evaluation plus the ECG and chestradiography showed statistical significance compared withthe cardio - respiratory aptitude (CRA) and the functional class (FC) obtained from the Ergometric Test (p = 0.0062; p= 0.0409). The patients classified in the severe stages of the Chagas’ heart disease presented lesser levels of CRA and FC compared with those in the benign stages. The other complexexams didn’t show significant association with the availableexams usually found in the Primary Health Units. Objective: The next step after the control of Chagas’ diseasetransmission is the investment in the prevention of the chagasic cardiopathy damage. This study intended to comparethe basic cardiologic investigation with the complex cardiologic investigation in Chagas’ heart disease. Methods: The study evaluated 52 medical records among 515 of the chagasic patients from the Ambulatory of the Chagas’Disease Study Group.(AU)

Involvement of the autonomic nervous system in Chagas heart disease

The autonomic nervous system and especially the intracardiac autonomic nervous system is involved in Chagas' disease. Ganglionitis and periganglionitis were noted in three groups ofpatients dying with Chagas'disease: 1) Those in heart failure; 2) Those dying a sudden, non violent death and; 3) Those dying as a consequence ofaccidents or homicide. Hearts in the threegroups also revealed myocarditis and scattered involvement of intramyocardial ganglion cells as well as lesions of myelinic and unmyelinic fibers ascribable to Chagas'disease. In mice with experimentally induced Chagas' disease weobserved more intensive neuronal lesions of the cardiac ganglia in the acute phase of infection. Perhaps neuronal loss has a role in the pathogenesis of Chagas cardiomyopathy. However based on our own experience and on other data from the literature we conclude that the loss of neurones is not the main factor responsible for the manifestations exhibited by chronic chagasic patients. On the other hand the neuronal lesions may have played a role in the sudden death ofone group of patients with Chagas'disease but is difficult to explain the group of patients who did not die sudderly but instead progressed to cardiac failure.

O sistema nervoso autônomo e especialmente o sistema nervoso autônomo intracardiaco são lesados na doença de Chagas. Ganglionite e periganglionite foram observadas em 1) chagásicos com insuficiência cardíaca; 2} em tripanossomóticos, assintomáticos ou paucissintomáticos, em vida, falecidos subitamente em conseqüência da doença de Chagas e 3) nos chagásicos, também assintomáticos, e que faleceram devido a acidentes ou homicídios. Em todos os três grupos os corações mostraram miocardite e lesões das células ganglionares intramiocárdicas bem como das fibras nervosas mielínicas e amielínicas. Em camundongos com infecção chagásica experimental, observamos que na fase aguda da doença as lesões são mais graves e intensas. A denervação talvez desempenhe algum papel na patogênese da cardiopatia chagásica. Entretanto, baseados em nossa experiência pessoal e em outros dados da literatura concluímos que a perda de neurônios não é o principal nem o fator exclusivo pelas manifestações apresentadas pelos pacientes chagásicos crônicos. Por outro lado, as lesões dos neurônios talvez possam ter algum papel no mecanismo da morte súbita do chagásico mas é difícil explicar porque tripanossomóticos, com lesões similares, não faleceram subitamente.