摘要目的 探讨超声二维斑点追踪成像分层应变技术评价不同时长维持性血液透析(maintenance hemodialysis , M HD)患者左心室壁跨壁心肌收缩功能的应用价值.方法 选取M HD患者68例,根据透析治疗时长分为透析龄＜3年组(B组, 31例)和透析龄≥3年组(C组, 37例) ,另选取年龄、性别相匹配的同期健康者30例为对照组(A 组) .采集各组标准左心室心尖四腔、三腔、两腔切面及左心室短轴二尖瓣水平、乳头肌水平及心尖水平二维灰阶图像,应用分层二维斑点追踪分析技术获取和比较各组左心室心内膜下、中层、外膜下心肌的纵向应变(LS)及周向应变(CS).绘制ROC曲线,比较各层心肌LS及CS诊断M HD患者左心室收缩功能异常的检验效能.结果 ① 跨壁整体应变: B 、 C两组M HD患者左心室壁各层心肌整体纵向应变(GLS)均低于A组( P ＜0 .01) ,与B组相比,C组MHD患者左心室壁各层GLS降低( P ＜0 .01) ;与A组相比,B组中层心肌及C组左心室壁各层心肌整体周向应变(GCS)均减低( P ＜0 .01) ,B 、 C两组各层GCS相比差异无统计学意义(P＞0 .05) .② 跨壁长轴各水平应变: B 、 C两组M HD患者各水平左心室壁三层心肌LS低于 A组( P ＜0 .05或 P ＜0 .01) ;与B组相比,C组M HD患者各水平左心室壁三层心肌LS降低( P ＜0 .05或 P ＜0 .01) .③ 跨壁短轴各水平应变:与A组相比,B组仅二尖瓣水平中间层心肌CS降低(P＜0 .05) , C组二尖瓣水平三层心肌及乳头肌水平、心尖水平中层心肌CS降低( P ＜0 .05或 P ＜0 .01) ;与B组相比, C组二尖瓣水平中、外层心肌周向应变均降低( P ＜ 0 .05 ) .④ ROC曲线显示,分别采用心肌各层GLS 、 GCS判定M HD 患者左心室收缩功能异常时,心内膜下心肌 GLS 的曲线下面积(AUC )为0 .851 ,以 －21 .45% 为截断值时,其敏感性为 72 .7%,特异性为 93 .3%;中层心肌 GCS 的 AUC为0 .683 ,以 －17 .08% 为截断值时,其敏感性为 58 .5%,特异性为 83 .3%.结论 随着透析时间延长, M HD患者左心室心肌收缩功能呈现进行性受损加重;超声分层应变技术能够量化评价左心室跨壁不同水平、不同方向和不同心肌层次的纵向及周向应变受损情况,有助于临床分期量化评价左心室心肌损伤程度并采取相应精确干预治疗措施.

abstractsObjective To assess the clinical ultrasound value of layer‐specific strain in evaluation of left ventricular systolic myocardial dysfunction of uremia patients after long‐time dialysis at different time . Methods A total of 68 uremia patients accepted maintenance hemodialysis ( M HD ) were enrolled . T he patients were divided into two groups according to the dialysis duration :dialysis time ＜3 years ( group B , n＝31) and dialysis time ≥3 years ( group C , n ＝37) . T he age and sex mached healthy cases were selected as control group ( group A , n ＝ 30 ) . T he standard dynamic two‐dimensional echocardiographic viewes of apical four‐chamber ,three‐chamber ,two‐chamber and the short‐axis view at three levels of mitral valve , papillary muscle and apex were acquired for three cardiac cycles . T he highest value of peak systolic longitudinal strain ( LS ) ,circumferential strain ( CS ) at different levels ,left venrticular global longitudinal strain ( GLS ) and global circumferential strain ( GCS ) were respectively assessed from endocardium ,mid‐myocardium and epicardium using GE EchoPAC workstation . T he comparisons of those parameters were performed among the 3 groups for differences . T he efficacies of GLS and GCS at different myocardial layers in diagdosing the left ventricular systolic function of M HD patients were analyzed by the ROC curve . Results ① Global transmural parameters :compared with those in group A ,the values of GLS at three myocardial layers in both M HD groups were significantly decreased ( all P ＜ 0 .01 ) ,the value of GLS at three myocardial layers in group C was also decreased ,and was statistically different from that in group B ( P＜0 .01) . Compared with those in group A ,the values of GCS at mid‐myocardium in group B and three myocardial layers in group C were also decreased ( all P ＜0 .01) . T here was no significant difference of GCS between group B and C ( P ＞0 .05) . ②Longitudinal transmural parameters at different levels :the values of LS at three myocardial layers of mitral valve ,papillary muscle and apex were decreased in group B and C compared with those in group A ( P ＜0 .05 or P ＜0 .01) ; T he values of LS at three myocardial layers of mitral valve ,papillary muscle and apical levels were also decreased in group C compared with those in group B ( P ＜0 .05 or P ＜0 .001) . ③Short‐axis transmural parameters at different levels :compared with those in group A ,the value of CS at mid‐myocardium of mitral valve level was decreased in group B ( P ＜0 .05) ,the values of CS at three myocardial layers of the mitral valve level and mid‐myocardium of papillary muscle level and apical level were decreased in group C ( P ＜0 .05 or P ＜0 .01) . Besides ,compared with those in group B ,the values of CS at mid‐myocardium and epicardium of mitral valve level were also decreased in group C ( P ＜0 .05) . ④ROC curve showed that determining left ventricular systolic dysfunction in M HD patients using GLS ,GCS at different myocardial layers ,when the area under the curve ( AUC ) of GLS of intima was 0 .851 ,the cut‐off value was －21 .45% ,the sensitivity was 72 .7% ,and the specificity was 93 .3% ; when the AUC of GCS of mid‐myocardium was 0 .683 ,the cut‐off value was －17 .08% , the specificity was 58 .5% , and the specificity was 83 .3% . Conclusions T he left ventricular systolic myocardial function is progressively damaged with the extended dialysis duration time . Ultrasonic layer‐specific strain technology could be used to quantitatively evaluate left ventricular systolic transmural myocardial dysfunction and might contribute to the evaluation of the severity of left ventricular myocardial dysfunction clinically for a more accurate intervention .