采用二维斑点追踪分层应变技术评价乳腺癌患者化疗后左心室收缩功能的变化及节段性特点

Evaluation of Changes and Segmental Characteristics of Left Ventricular Regional Function in Breast Cancer Patients After Chemotherapy by Layer-specific Two-dimensional Speckle Tracking Imaging

目的:采用二维斑点追踪分层应变技术(LS2D-STI)评价乳腺癌患者化疗后左心室收缩功能的变化及节段性特点,探讨该技术在乳腺癌患者化疗后心脏毒性评估中的价值。方法:选取66例乳腺癌术后接受化疗的患者,于化疗前(T0)及开始化疗后3个月(T3)、6个月(T6)、12个月(T12)行常规和LS2D-STI超声心动图检查。采用EchoPAC分析软件测量左心室各层心肌(包括心内膜下、中层、心外膜下心肌)的纵向应变(LS)。结果:在各个随访时间节点,患者的左心室射血分数较基线均轻度稳定下降(P均<0.05),但仍在正常范围内(>50%)。与T0相比,T3时心内膜下、中层心肌LS及T12时心内膜下、中层、心外膜下心肌LS均明显下降(P均<0.05);其中心内膜下心肌LS较基线的下降幅度(ΔLS)最大,但与其他两层心肌ΔLS比较差异均无统计学意义(P均>0.05)。左心室各节段各层心肌应变分析显示,心尖段心内膜下心肌损伤最显著。结论:LS2D-STI可定量分析左心室整体和节段收缩功能,比常规超声心动图更灵敏。化疗药物对左心室心尖段心内膜下心肌功能的影响最大。

Objectives:This study aimed to analyze the changes and segmental characteristics of left ventricular systolic function in patients with breast cancer after chemotherapy by layer-specific two-dimensional speckle tracking imaging(LS2D-STI),and to explore the value of this technique for assessing cardiotoxicity of chemotherapy.Methods:66 breast cancer patients undergoing chemotherapy were enrolled.Conventional echocardiography and LS2DSTI were performed before chemotherapy(T0)and at 3 months(T3),6 months(T6),and 12 months(T12)post chemotherapy.The strains of different layers of left ventricle including peak systolic longitudinal strain(endo LS,mid LS,epi LS)were measured using EchoPAC analysis software.Results:Left ventricular ejection fraction showed a mild and stable reduction at every follow-up time point compared to the baseline(all P<0.05),while remaining within the normal range(>50%).Compared with T0,endo LS,mid LS decreased significantly at T3,while endo LS,mid LS,epi LS decreased significantly at T12(all P<0.05).The most decrease(ΔLS)was evidenced at endo LS,but there were no significant differences between endo LS,mid LS and epi LS(both P>0.05).Moreover,the strain analysis showed that the most significant myocardial injury occurred under the endocardium of the apical.Conclusions:LS2D-STI can quantitatively analyze global and regional systolic functions of left ventricular post chemotherapy,and is more sensitive than conventional echocardiography on the assessment of chemotherapy.Chemotherapeutic agents may have the greatest negative effect on left ventricular apical subendocardial myocardium.