Cardiac Imaging in Latin America: Chagas Heart Disease

Patients with Chagas heart disease can be evaluated for diagnostic and prognostic purposes using several imaging methods, including the plain chest radiography and various echocardiography techniques for biventricular systolic and diastolic function assessment, myocardial perfusion scintigraphy for uncovering microvascular disturbances, and 123iodine-MIBG labeling of sympathetic myocardial innervation, MRI for detection and quantitation of myocardial fibrosis, and coronary angiography during cardiac catheterization to characterize the mechanism of myocardial ischemia. Through the careful analysis and integration of findings provided by the application of these imaging methods to patients with various stages of chronic Chagas cardiomyopathy, it has been possible to improve considerably the understanding of some pathophysiological peculiarities of the disease. These include: (a) the predominant systemic congestion when cardiac failure supervenes, due to early impairment of RV function; (b) the early typical LV regional wall motion abnormalities, topographically correlated with microvascular ischemic defects despite normal coronary arteries, and preceded by local sympathetic denervation; (c) the characteristic extensive myocardial fibrosis that is a hallmark of the disease and is causally related to the frequent occurrence of sudden death even in patients with globally preserved LV systolic function. Ongoing research, mainly focused on the refinement of echocardiographic techniques and further exploration of nuclear and MRI methods, have the potential to contribute to a better prognostic stratification of patients with chronic Chagas cardiomyopathy. © 2015, Springer Science+Business Media New York.