心肌分层应变技术评价不同心功能尿毒症患者左室纵向功能

Left ventricular myocardial layer-specific strain in uremia patients of different heart function

目的:探讨应用心肌分层应变技术评价不同心功能的尿毒症患者左室纵向收缩功能的价值。方法:选取75例尿毒症患者,根据左室射血分数(LVEF)分为心功能正常(LVEF≥50%)组(43例)和心功能减退(LVEF<50%)组(32例),另设40例健康者作为对照组。先行常规心脏数据测量,然后应用斑点追踪成像(STI)中的分层应变技术获取3组心尖位3个长轴切面心内膜下、中层和心外膜下心肌收缩期纵向峰值应变(LS)。结果:(1)与对照组比较,心功能正常组和心功能减退组的收缩期左房内径(LAESd)、收缩期室间隔厚度(IVSTd)、舒张期左室后壁厚度(LVPWTd)和二尖瓣口舒张早期血流速度/舒张末期血流速度(E/A)值比较的差异均有统计学意义(均P<0.01);(2)与对照组及心功能正常组比较,心功能减退组的LAESd、舒张期左室内径(LVDd)及LVEF减低,均差异有统计学意义(均P<0.01);(3)3组患者间的LS值由心内膜下至心外膜下心肌保持梯度递减;(4)与对照组比较,心功能正常组心内膜下心肌LS值减低,差异有统计学意义(P<0.05),心功能减退组3层心肌LS值减低明显,差异有统计学意义(P<0.01);(5)与心功能正常组比较,心功能减退组部分心肌LS值减低,差异有统计学意义(P<0.05)。结论:不同心功能的尿毒症患者左室壁3层心肌LS值受累程度不同,心肌纵向分层应变不但可以比LVEF更早发现左室收缩功能减低,还可以判断病变受累程度。

Objective：To investigate the value of myocardial layer-specific strain using speckle tracking imaging （STI） in evaluating the left ventricular peak systolic longitudinal strain（LS）in patients with uremia of different heart function. Method： Totally 75 patients with uremia were divided into normal cardiac group （n=43, LVEF≥ 50%） and cardiac dysfunction group（n=32,LVEF〈50%）according to the left ventricular ejection fraction （LVEF）. 40 healthy volunteers were selected as controls. Routine parameters were determined by echocardiography in 75 uremic patients and 40 healthy controls. High frame rate two-dimensional images were recorded from the apical four-chamber view, two-chamber view and long-axis during three consecutive cardiac cycles. Peak systolic longitudinal strain（LS） was measured in subendocardium, midmyocardium, subepicardium. Result： （1）Compared with healthy control group, left atrial end-systolic diameter （LAESd）, interventricular septum thickness （IVSTd）, left ventrieular posterior wall thickness at end-diastole （LVPWTd） , and E/A were significantly different in both normal cardiac group and cardiac dysfunction group（P〈0.01）. （2）There were significant difference in LAESd,LVDd and LVEF in between cardiac dysfunction group, normal cardiac group and control group （P 〈0.01）. （3）LS decreased from endocardium to epicardium gradually in all three groups. （4）Compared with the control group, LS of normal cardiac group was lower（P〈0.05）, and more significantly lower in cardiac dysfunction group. （5）Compared with normal cardiac group, part of longitudinal 3-layer strain in cardiac dysfunction group was reduced（P〈0.01）. Conclusion：Layer-specific strain may quantitatively evaluate the layered myocardial strain, and it＇s earlier than LVEF that decreases cardiac contractivity in patients with uremia.