速度向量成像技术定量评价正常人左心室扭转运动

Quantitative assessment of left ventricular torsion in normal subjects using vector velocity imaging

目的采用速度向量成像技术研究正常人的左心室心内膜和心外膜扭转运动特点。方法对10例正常成年人行常规超声心动图和二维斑点显像检查。斑点追踪切面包括基底切面（二尖瓣水平左心室短轴）和心尖切面（心尖水平左心室短轴），应用Siemens SyngoWorkPlace V2．0工作站进行后处理分析。结果无论是心内膜或心外膜，左心室基底部收缩期旋转均为负值，舒张期旋转均为正值，心尖部则相反，收缩期心尖部旋转速度的绝对值显著高于基底部[心内膜：（150±62）°／s对（114±65）°／s；心外膜：（81±40）°／s和（55±28）°／s，均P〈0.01）]。无论是基底部或心尖部，收缩期心内膜旋转速度和旋转角度均显著高于心外膜[基底部：（-114±65）°／s对（-55±28）°／s，（-12±6）°对（-4±1）°；心尖部：（150±62）°／s对（81±40）°／s，（10±4）°对（6±2）°，均P〈0．05）]。收缩期基底部和心尖部心内膜和心外膜平均旋转速度达峰时间[基底部（188±72）ms对（187±55）ms；心尖部（195±85）ms对（141±79）ms]、舒张期基底部和心尖部心内膜和心外膜平均旋转速度达峰时间[基底部（446±58）ms对（491±53）ms；心尖部（453±57）ms对（466±85）ms]及收缩期心内膜和心外膜平均旋转的达峰时间[基底部（296±69）ms对（292±63）ms；心尖部（251±67）ms对（295±66）ms]差异均无统计学意义（P〉0．05）。结论速度向量成像技术可无创伤性评价左心室环向旋转和扭转运动，正常人左心室具有特征性旋转运动。

Objective To evaluate the left ventricular（LV） torsion and rotation in normal subjects using vector velocity imaging. Methods LV basal and apical short-axis images were captured in 10 healthy individuals to estimate LV torsion and rotation using routine 2-dimensional echocardiography and vector velocity imaging. Results As viewed from LV apex, the systolic basal rotation was clockwise （negative value） ,and apical rotation was counterclockwise （positive value）. The apical peak systolic rotational velocity was significantly higher than the basal [-endo ： （ 150 ± 62）°/s vs （ 114 ± 65 ）°/s ; epi ： （81 ± 40）°/s vs （55± 28）°/s, respectively, P 〈 0.01]. The peak systolic endocardial rotational velocity and rotation was significantly higher than epicardial rotational velocity and rotation[basal： （ - 114 ± 65）°/s vs （ - 55 ± 28）°/s,（-12±6）° vs （-4±1）°;apical： （150±62）°/s vs （81±40）°/s,（10±4）° vs （6±2）°,respectively, P 〈 0.05]. There were no significant differences in the time to peak systolic rotational velocity/rotation between basal endocardium/epicardium and apical endocardium/epicardium. Conclusions Vector velocity imaging can assess LV torsion and rotation non-invasively, and normal LV has a kind of characteristic motion of torsion.