定量组织多普勒Tei指数评价模拟失重对健康成人心室功能的影响

摘要

目的 应用超声心动图定量组织多普勒推导的Tei指数评价模拟失重对健康成人心室功能的影响.方法 健康青年男性志愿者12名,-6°头低位卧床模拟失重.以平卧10 min静息状态作为实验对照组,行多普勒超声心动图检查,以后分别于模拟失重第10天、第20天重复行多普勒超声心动图检查.在同步心电图R波触发下,存储组织速度成像(TVI)模式的心尖四腔心切面图像.将定量组织多普勒(QTVI)取样点置于二尖瓣环左侧位点,得到二尖瓣环左侧位点QTVI曲线,测量计算左心室Tei指数;将QTVI取样点置于三尖瓣环右侧位点,得到三尖瓣环右侧位点QTVI曲线,测量计算右心室Tei指数.结果 模拟失重第10天、第20天,左心室Tei指数与对照组间差异无统计学意义.模拟失重第10天、第20天与对照组比较,右心室Tei指数均增大(P<0.05),而模拟失重第10天、第20天之间左、右心室Tei指数比较差异无统计学意义.结论 持续模拟失重未能引起健康成人左心室功能改变,但可致右心室功能减退.%Objective To assess the influence of simulated weightlessness on the ventricular function with Tei indices in the healthy adults by quantitative tissue ve10city imaging( QTVI ) with echocardiography. Methods Twelve young volunteers were chosen to simulate weightlessness condition by continuous 6 degree head down tilt bed rest. Echocardiography examinations were arranged at 10 minutes after start of the experiment on the 10th day and 20th, respectively in prostration at rest condition. Tissue Doppler figures were obtained from the apical four-chamber view, and the technique of the QTVI was used to measure and calculate Tei indices of left and right ventricle. Tei indices of left ventricle were observed in the left lateral position of mitral ring. The Tei indices of right ventricle were found in the right lateral position of tricuspid annulus. The data were analyzed by SPSS 11.0, and the differences among these groups were analyzed by analysis of variance. Results There was no difference in Tei indices of left ventricle among the control group, the 10th day group and the 20th group. The Tei indices of right ventricle increased on the 10th day and the 20th day of simulated weightlessness compared with those in the control group, but no significant difference between those on the 10th day group and the 20th day group was observed.Conclusions Within this experiment' s time limit under the condition of simulated weightlessness , Tei indices of left ventricle had no significant changes , but Tei indices of right ventricle significantly increased. The results demonstrated continuous simulated weightlessness could not change left ventricular function, but could decrease right ventricular function in the healthy adults within time limit under the condition of simulated weightlessness.