三维斑点追踪技术评价-30°头低位心肌功能适应性改变的研究

Assessment of cardiac function in-30°head-down state by three-dimensional speckle tracking technology

目的利用三维斑点追踪技术(3D-STE)优势,探究模拟短期失重状态下心脏功能的调节变化特点。方法15名男性青年志愿者进行-30°头低位卧床45min实验,分别在实验前后及头低位状态第15、30、45min进行常规心脏超声和三维斑点追踪检查。结果左心室整体纵向应变(GLS)在30min后与安静时刻对比应变率显著降低(P<0.05),且第30min时GLS与心输出量(CO)、左心室射血分数(LVEF)存在负相关(r=-0.49、-0.62,P<0.05),整体圆周应变(GCS)、整体面积应变(GAS)及扭力在实验过程中均未发生明显改变。结论头低位过程中,心肌收缩减低,尤其以纵向运动减少为著。GLS比GCS和GAS更为敏感反映心脏收缩功能的改变,该指标可作为3D-STE评价-30°HDT的敏感指标。

Objective To explore the regulatory characteristics of cardiac function under simulated short-term weightless by using the advantages of three-dimensional speckle tracking technology.Methods Fifteen young male volunteers performed echocardiography in-30°head-low for 45min.Images were stored at the 15th,30th and 45th min.Results After 30min GLS decreased significantly compared with the rest(P<0.05)and GLS correlated negatively with CO、LVEF respectively(r=-0.49、-0.62,P<0.05).GCS,GAS and torsion did not change significantly during the experiment.Conclusion Myocardial contraction decreases during the head-down level,especially in longitudinal motion.GLS is more sensitive than GCS and GAS reflecting altered cardiac systolic function.The index can be used as a sensitive indicator for 3D-STE evaluation-30°HDT.