二维超声斑点追踪评价重型地中海贫血患儿左心室内外膜心肌旋转运动的初步研究

目的：应用二维超声斑点追踪技术评价重型地中海贫血患儿左心室旋转收缩功能早期损害。方法：对60例地中海贫血患儿及30例正常儿童行常规超声心动图检查。患儿按照血清铁蛋白（SF）水平分为A、B两组：A组SF≥2 500 μg/L，30例，B组SF＜2 500 μg/L，30例。测定所有入选儿童左心室心底部、中间部及心尖部内外膜心肌圆周向收缩期峰值应变。结果：①与正常组比较，A组3个不同水平内膜心肌圆周向应变均明显减低，与正常组及B组均有显著性差异（P＜0.05）。②A组的外膜心肌圆周向应变只有心尖部明显减低，并与正常组有显著性差异（P＜0.05）。③B组只有心尖部内膜心肌圆周向应变值明显减低，且与正常组有显著性差异（P＜0.05）。结论：二维超声斑点追踪技术能够发现常规超声不能检出的重型地中海贫血患儿早期心肌旋转收缩功能损害，SF水平较高组患儿的心肌功能受损较严重。

Left ventricular endocardial and epicardial circumferential dysfunction by two-dimensional speckle tracking imaging in thalassemia major children

Objective： To analyze the early circumferential dysfunction of left ventricular（LV） endocardium and epicardium in thalassemia major children by using two-dimensional speckle tracking imaging（2D-STI）.Methods： Routine echocardiography was performed in 60 thalassemia major children and 30 normal children.Patients were divided into 2 groups： 30 cases of thalassemia A,with serum ferritin（SF）≥2 500 μg/L,30 cases of thalassemia B,with serum ferritin（SF）2 500 μg/L.Two-dimensional images were recorded.Then the circumferential peak systolic strains（PSS） of endocardium and epicardium were measured at basal,mid and apical levels of LV for all the subjects.Results： ①Compared with normal group and group thalassemia B,endocardial circumferential PSS of group thalassemia A decreased significantly（P0.05） in all the three level views of LV（P0.05）.② Compared with normal group,epicardial circumferential PSS of group thalassemia A decreased significantly only in apical level view（P0.05）.③ Compared with normal group,endocardial circumferential PSS of group thalassemia B decreased significantly only in apical level view（P0.05）.Conclusions： 2D-STI circumferential strain can detect the early circumferential dysfunction of LV in thalassemia major children,which is difficult to be detected by routine echocardiography.The LV circumferential dysfunction of group A with high level SF is more serious than that of group B with low level SF.