Analysis of Regional Left Ventricular Strain in Patients with Chagas Disease and Normal Left Ventricular Systolic Function

Background: Chagas heart disease has a high socioeconomic burden, and any strategy to detect early myocardial damage is welcome. Speckle-tracking echocardiography assesses global and segmental left ventricular (LV) systolic function, yielding values of two-dimensional strain (ε). The aim of this study was to determine if patients with chronic Chagas disease and normal LV ejection fractions present abnormalities in global and segmental LV ε.

Methods: In this prospective study, patients with Chagas disease with no evidence of cardiac involvement (group I; n = 83) or at stage A of the cardiac form (i.e., with changes limited to the electrocardiogram) (group A; n = 42) and 43 control subjects (group C) underwent evaluation of global and segmental LV ε by speckle-tracking echocardiography. A subset of randomly selected patients in group A underwent cardiac magnetic resonance imaging and repeated echocardiography 3.5 ± 0.8 years after the first evaluation.

Results: Mean age, chamber dimensions, and LV ejection fraction were similar among the groups. Global longitudinal (group C, -19 ± 2%; group I, -19 ± 2%; group A, -19 ± 2%), circumferential (group C, -19 ± 3%; group I, -20 ± 3%; group A, -19 ± 3%), and radial (group C, 46 ± 10%; group I, 45 ± 13%; group A, 42 ± 14%) LV ε were similar among the groups. Segmental longitudinal, circumferential, and radial LV ε were similar across the studied groups. Seven of 14 patients had areas of fibrosis on cardiac magnetic resonance imaging. Patients with fibrosis had lower global longitudinal (-15 ± 2% vs -18 ± 2%, P = .004), circumferential (-14 ± 2% vs -19 ± 2%, P = .002), and radial LV ε (36 ± 13% vs 54 ± 12%, P = .02) than those without cardiac fibrosis despite similar LV ejection fractions. Patients with fibrosis had lower radial LV ε in the basal inferoseptal wall than patients without cardiac fibrosis (27 ± 17% vs 60 ± 15%, P = .04).

Conclusions: Patients with chronic Chagas disease and normal global and segmental LV systolic function on two-dimensional echocardiography had global and segmental LV ε similar to that of control subjects. However, those in the early stages of the cardiac form and cardiac fibrosis had lower global longitudinal, circumferential, and radial LV ε.