Gomes Victor Augusto M, Alves Gabriel F, Hadlich Marcelo, Azevedo Clerio F, Pereira Iane M, Santos Carla Renata F, Brasil Pedro Emmanuel A A, Sangenis Luiz Henrique C, Cunha Ademir B, Xavier Sergio S, Saraiva Roberto M
Instituto Nacional de Cardiologia, Rio de Janeiro, Brazil.
Instituto Nacional de Infectologia Evandro Chagas, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil.
J Am Soc Echocardiogr. 2016 Jul;29(7):679-88. doi: 10.1016/j.echo.2016.03.007. Epub 2016 Apr 14.
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.
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.
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).
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.
恰加斯心脏病具有很高的社会经济负担，任何检测早期心肌损伤的策略都值得欢迎。斑点追踪超声心动图可评估左心室（LV）整体和节段性收缩功能，得出二维应变（ε）值。本研究的目的是确定慢性恰加斯病且左心室射血分数正常的患者在左心室整体和节段性ε方面是否存在异常。
在这项前瞻性研究中，无心脏受累证据的恰加斯病患者（I组；n = 83）或心脏型A期患者（即改变仅限于心电图）（A组；n = 42）以及43名对照受试者（C组）接受了斑点追踪超声心动图对左心室整体和节段性ε的评估。A组中随机选择的一部分患者在首次评估后3.5±0.8年接受了心脏磁共振成像和重复超声心动图检查。
各组间的平均年龄、心腔大小和左心室射血分数相似。各组间左心室整体纵向应变（C组，-19±2%；I组，-19±2%；A组，-19±2%）、圆周应变（C组，-19±3%；I组，-20±3%；A组，-19±3%）和径向应变（C组，46±10%；I组，45±13%；A组，42±14%）相似。所研究组间节段性纵向、圆周和径向左心室ε相似。14名患者中有7名在心脏磁共振成像上有纤维化区域。尽管左心室射血分数相似，但有纤维化的患者左心室整体纵向应变（-15±2%对-18±2%，P = 0.004）、圆周应变（-14±2%对-19±2%，P = 0.002）和径向应变（36±13%对54±12%，P = 0.02）低于无心脏纤维化的患者。有纤维化的患者基底下间隔壁的径向左心室应变低于无心脏纤维化的患者（27±17%对60±15%，P = 0.04）。
二维超声心动图显示左心室整体和节段性收缩功能正常的慢性恰加斯病患者，其左心室整体和节段性ε与对照受试者相似。然而，处于心脏型早期且有心脏纤维化的患者左心室整体纵向、圆周和径向应变较低。
