超声二维斑点追踪显像评价肥厚型心肌病左心室扭转和径向位移的初步研究

目的 采用超声二维斑点追踪显像技术(STI)探讨肥厚型心肌病(HCM)患者左室扭转运动的特征.方法 随机选取心功能测值正常的HCM患者及正常对照各35例,取胸骨旁左室心尖和心底短轴观二维图像对左室旋转及径向位移进行测量分析,记录并计算心底部旋转角度峰值(Prot-MV)、心尖部旋转角度峰值(Prot-AP)、扭转角度峰值(Ptw)、收缩期末扭转角度(AVCtw))、等容舒张期末扭转角度(MVOtw)、解旋率(Untw R)、解旋减半时间(HTU)、收缩期末径向位移(AVCdisp)、等容舒张期径向位移(IVRTdisp),比较两组间上述各参数的差别;同时构建左室扭转一径向位移环,并分析其各形态参数.结果 ①与对照组比较.HCM组Prot-MV、Prot-AP、Ptw、AVCtw、MVOtw、HTU测值均增加,Untw R测值减低,两组间差异均有统计学意义(P均＜0.05),而AVCdisp、IVRTdisp测值差异无统计学意义.②HCM组内左室旋转心尖部达峰时间较心底部测值增加,差异有统计学意义(P＜0.05).③与对照组比较,HCM组收缩期及等容舒张期左室扭转-径向位移环的变化斜率均增加,差异均有统计学意义(P均＜0.05).结论 STI显示HCM患者左室旋转运动力学参数较正常人有明显异常改变.

Initial exploration of evaluation of left ventricular twist and radial displacement in patients with hypertrophic cardiomyopathy by speckle-tracking imaging

Objective To evaluate the left ventricular twist and radial displacement in patients with hypertrophic cardiomyopathy(HCM)by 2-dimensional(2D)ultrasound speckle-tracking imaging(STI).Methods 2D images of left ventricle at basal and apical short-axis views were acquired in 35 patients with HCM and 35 healthy subjects,and then were analysed off line to assess left ventricular(LV)rotation and radial displacement.Peak rotation(Prot)and the time to peak rotation in basal and apical short axis views were measured separately.Peak twist(Ptw),twist at aortic valve closure(AVCtw),twist at mitral valve opening(MVOtw),untwisting rate(Untw R),half time of untwisting(HTU),radial displacement were also calculated and compared and compared between HCM group and the control group.Based on the value of radial displacement,the LV twist-displacement loop was established and the features of the loop were analyzed.Results ①Compared with the control group,the value of Prot-MV,Prot-AP,Ptw,AVCtw,MVOtw and HTU increased significantly(all P＜0.05)and the Untw R decreased(P＜0.05)in the HCM group.②In HCM group,time to Prot in apical view was higher than that in basal.③ Twist-displacement loops could be constructed noninvasively.The liner slope changed significantly in HCM group compared with that of the control group.Conclusions The characteristics of LV rotation in patients with HCM were significantly different from the normals,and the STI measurement could be used noninvasively to evaluate the characteristics of LV twist and radial displacement.