Evidence of Early Cardiomyopathy with Strain in Chagas Disease

pp 323-329

Abstract

Background: In Chagas’ disease, cardiomyopathy is the most severe affection produced by this parasitic disease; its slow progression has led to several investigations in search of parameters capable of detecting incipient myocardial damage. Currently, the incorporation of strain by speckle tracking echocardiography opens a new horizon.
Objective: The aim of this study was to investigate the role of two-dimensional echocardiography in Chagas disease and in the detection of incipient cardiomyopathy.
Methods: A cross-sectional study was performed between December 2009 and March 2011, including 93 patients with Chagas disease. Forty-five patients were men and mean age was 46±12 years. The patients were divided into three groups (G): G1 (n=40) without demonstrable heart disease), G2 (n=17) with abnormal electrocardiogram and G3 (n=36) with cardiomyopathy. A control group consisted of 35 subjects; 19 were men and mean age was 40±10 years. Doppler echocardiography was performed to evaluate left ventricular diameters, left atrial area, left ventricular ejection fraction (Simpson), mitral annular plane systolic excursion and
tricuspid annular plane systolic excursion. Mitral inflow pattern evaluated E wave, A wave, mitral E wave deceleration time and E/A ratio. Pulsed tissue Doppler imaging was used to measure and compare velocities at the lateral mitral annulus and tricuspid annulus(E’ wave, A’ wave, E’/A’ ratio and S’ wave) and global and segmental longitudinal peak systolic strain.
Results: Global longitudinal peak systolic strain correlated with mitral annular plane systolic excursion (r: 0.75) in the pool of patients with Chagas disease. Segmental longitudinal peak systolic strain differentiated two or more abnormal segments (value below -12%) in 10 patients of the group without demonstrable heart disease. This subgroup (n=10) had lower values of global longitudinal peak systolic strain (-19.78% vs. -22.28%; p=0.009), lower E’/A’ ratio in the mitral annulus (1.23±0.59; p=0.021) and tricuspid annulus (0.73±0.3; p=0.019), with inverted E’/A’ ratio in the tricuspid annulus compared with the rest of the group (n=30).
Conclusions: Global longitudinal peak systolic strain correlated with mitral annular plane systolic excursion. Segmental longitudinal
peak systolic strain differentiated a subpopulation in the group without demonstrable heart disease with abnormal segments,low values of global longitudinal peak systolic strain and biventricular diastolic dysfunction by pulsed tissue Doppler imaging. Theclinical value of this finding requires longitudinal follow-up.