正常人左室收缩功能的超声三维斑点追踪研究

目的运用三维斑点追踪成像技术(3D-STI)评价正常人左室短轴及长轴心肌应变特征,探讨其对正常人左室收缩功能的评判价值。方法健康志愿者45名,采集标准左室长轴心尖四腔、三腔切面左室全容积图像进行在线分析,自动计算左室舒张末期容积(LVEDV)、左室收缩末期容积(LVESV)、左室射血分数(LVEF)、左室短轴径向各水平收缩期峰值及平均应变、左室短轴环向各水平收缩期峰值及平均应变、左室长轴纵向各水平收缩期峰值及平均应变,分析各应变指标变化情况。结果正常人左室短轴径向各节段收缩期峰值及平均应变,基底水平较中间段水平增大(P<0.05),中间段水平较心尖水平增大(P<0.05),基底水平较心尖水平增大(P<0.01)。正常人左室短轴环向各节段收缩期峰值及平均应变,心尖水平较中间段水平增大(P<0.05),中间段水平较基底水平增大(P<0.05),心尖水平较基底水平增大(P<0.01)。正常人左室长轴纵向收缩期峰值及平均应变,心尖水平较中间段水平增大(P<0.05),中间段水平较基底水平增大(P<0.05),心尖水平较基底水平增大(P<0.01)。结论 3D-STI可无创、客观评价正常人在不同水平和不同节段径向、环向、纵向心肌应变,为定量评价正常人左室收缩功能提供了一种新的思路。

Assessment of left ventricular strain in healthy human by three-dimensional speckle tracking imaging

Objective To assess the left ventricular systolic function in healthy human by evaluation the left ventricular strain in short-axis and long-axis using three-dimensional speckle tracking imaging （3D-STI）. Method A total of 45 healthy volunteers were chosen to evaluate left ventricular end-systolic and end-diastolic volume （LVESV and LVEDV）, and left ventricular ejection fraction （LVEF）. The strain of left ventricular long-axis and short-axis of each case was investigated by 3D- STI which employed full volume 3D acquisition and subsequent quantitative analysis. Results To those healthy human, left ventricular short-axial radial systolic peak and average strain values in each segment at based level were higher than those at middle level （P〈0.05）, those at middle level were also higher than those at apical level （P〈0.05）, and those at basic level were significantly higher than those at apical level （P〈0.01）. Left ventricular short-axial circumferential systolic peak and average strain values in each segmenl at apical level were higher than those at middle level （P〈0.05）, those at middle level were higher than those at basic level （P〈0.05）, those at apical level were significantly higher than those at basic level （P〈Z0.01）. Left ventricular long-axis systolic peak and average strain values in each segment at apical level were higher than those at based level （P〈0.05）, and those at middle level were higher than those at basal level （P〈0.05）, and those at apical level were significantly higher than those at basal level （P〈0.01）. Conclusion 3D-STI is a no-invasive and objective method to evaluate left ventricular radial, circumferential and longitudinal strain of all segments in healthy human.