Chagas disease remains one of the most prevalent
infectious diseases in Latin America, and has become a health problem in non-endemic countries.
Dilated cardiomyopathy is the most severe manifestation of
Chagas disease, which causes substantial disability and early mortality in the socially most productive population leading to a significant economical burden. Prompt and correct diagnosis of
Chagas disease requires specialized clinical expertise to recognize the unique features of this disease. The appropriate and efficient use of cardiac imaging is pivotal for diagnosing the cardiac involvement in
Chagas disease, to stage the disease, assess patients' prognosis and address management. Echocardiography is the most common imaging modality used to assess, and follow-up patients with
Chagas disease. The presence of echocardiographic abnormalities is of utmost importance, since it allows to stage patients according to
disease progression. In early stages of cardiac involvement, echocardiography may demonstrate segmental left ventricuar wall motion abnormalities, mainly in the basal segments of inferior, inferolateral walls, and the apex, which cannot be attributed to obstructive coronary artery arteries. The prevalence of segmental wall motion abnormalities varies according to the stage of the disease, reaching about 50% in patients with left ventricular dilatation and dysfunction. Speckle tracking echocardiography allows a more precise and quantitative measurement of the regional myocardial function. Since segmental wall motion abnormalities are frequent in
Chagas disease, speckle tracking echocardiography may have an important clinical application in these patients, particularly in the indeterminate forms when abnormalities are more subtle. Speckle tracking echocardiography can also quantify the heterogeneity of systolic contraction, which is associated with the risk of arrhythmic events. Three-dimensional (3D) echocardiography is superior to conventional two-dimensional (2D) echocardiography for assessing more accurately the left ventricular apex and thus to detect apical
aneurysms and
thrombus in patients in whom ventricular foreshortening is suspected by 2D echocardiography. In addition, 3D echocardiography is more accurate than 2D Simpson s biplane rule for assessing left ventricular volumes and function in patients with significant wall motion abnormalities, including
aneurysms with distorted ventricular geometry. Contrast echocardiography has the advantage to enhancement of left ventricular endocardial border, allowing for more accurate detection of ventricular
aneurysms and
thrombus in
Chagas disease. Diastolic dysfunction is an important hallmark of
Chagas disease even in its early phases. In general, left ventricular diastolic and systolic dysfunction coexist and isolated diastolic dysfunction is uncommon but may be present in patients with the indeterminate form.
Right ventricular dysfunction may be detected early in the disease course, but in general, the clinical manifestations occur late at advanced stages of
Chagas cardiomyopathy. Several echocardiographic parameters have been used to assess right ventricular function in
Chagas disease, including qualitative evaluation, myocardial performance index, tissue Doppler imaging, tricuspid annular plane systolic excursion, and speckle tracking strain. Cardiac magnetic resonance (CMR) is useful to assess global and regional left ventricular function in patients with Chagas diseases. Myocardial
fibrosis is a striking feature of
Chagas cardiomyopathy and late
gadolinium enhancement (LGE) is used to detect and quantify the extension of myocardial
fibrosis. Myocardial
fibrosis might have a role in risk stratification of patients with
Chagas disease. Limited data are available regarding right ventricular function assessed by CMR in
Chagas disease.
Radionuclide ventriculography is used for global biventricular function assessment in patients with suspected or definite cardiac involvement in
Chagas disease with suboptimal acoustic window and
contraindication to CMR. Myocardial perfusion scintigraphy may improve risk stratification to define cardiac involvement in
Chagas disease, especially in the patients with devices who cannot be submitted to CMR and in the clinical setting of Chagas patients whose main complaint is atypical
chest pain. Detection of reversible ischemic defects predicts further deterioration of left ventricular systolic function and helps to avoid unnecessary cardiac catheterization and coronary angiography.
Conclusion: