【摘要】 目的使用斑点追踪显像(speckle tracking imaging,STI)技术评价正常成人左室扭转和解旋运动,并探讨年龄对其运动的影响。方法记录76例健康成人的左室基底部和心尖部短轴高帧频二次谐波图像,应用二维应变分析软件分别获得2个平面的旋转角度-时间和旋转速度-时间曲线,根据其平均值绘制左室整体的扭转角度-时间和扭转速度-时间曲线,测量扭转峰值、等容舒张末期扭转角度、扭转速度峰值及达峰时间,计算解旋率。结果收缩期左室产生扭转运动,包括基底部顺时针旋转和心尖部逆时针旋转,收缩末后立即发生快速解旋运动。老年组的扭转峰值、等容舒张末期扭转角度明显大于中年组(P<0.001)和青年组(P<0.001),老年组(P<0.05)及中年组(P<0.05)的解旋率明显低于青年组,扭转速度负向达峰时间也延迟(P<0.05)。结论二维斑点追踪技术可以无创评价左室扭转和解旋运动,年龄是其影响因素。更多还原

【Abstract】 Objective To assess left ventricular(LV)twist and untwist and to study the changes with normal aging on speckle tracking imaging(STI).Methods Basal and apical LV short-axis of second harmonic images with high frame rate were acquired in 76 healthy volunteers.Using two-dimensional strain software,LV rotation and rotational velocity versus time profiles were obtained at each level.LV twist was defined as apical rotation relative to the base.So the LV twist and twist velocity versus time profiles could be drawn.The peak twist,time to peak twist,twist at the end of isovolumic relaxation period,peak twist velocity and time to peak twist velocity were respectively measured,and the rate of LV untwisting was calculated.Results During systole,the LV performed a wringing motion with a counterclockwise rotation at the apex and a clockwise rotation at the base.After end systole,rapid untwisting developed.Peak LV twist was significantly higher(P<0.001),and the rate of LV untwisting,time to negative peak twist velocity were significantly reduced and delayed along with advancing ages(P<0.05).Conclusions LV twist and untwist can be measured noninvasively on speckle tracking imaging.Age is an influencing factor.更多还原