定量组织速度成像及应变率成像对高血压病患者左室舒张功能的研究

目的:探讨二尖瓣环舒张早期峰值速度及应变率与舒张晚期峰值速度及应变率评价左室舒张功能的价值。方法:取心尖四腔心切面,获取44例高血压病患者及20例正常人的二尖瓣前后叶瓣环的组织速度曲线和应变率曲线,分别测量舒张期峰值速度(Ve、Va)及舒张期峰值应变率(e、a);计算前后瓣环的平均峰值速度(EVe、EVa)及比率(EVe?蛐EVa);平均峰值应变率(Ee、Ea)及比率(Ee/Ea)。用血流多普勒法测定二尖瓣口血流峰值速度(E、A)及比率(E/A),并进行比较。结果:与对照组相比,高血压病患者EVe,EVe/EVa和Ee,Ee/Ea明显降低,且高血压肥厚组(LVH组)比非肥厚组(non-LVH组)降低更甚,EVa则明显升高,Ee/Ea比率与EVe/EVa比率呈高度显著相关(rs’=0.890,P<0.001),二者对左室舒张功能异常的检出率明显高于E/A比率(P<0.001)。结论:QTVI及SRI能便捷准确地定量高血压病患者二尖瓣环舒张期运动速度及应变率,揭示左心室舒张功能的改变,有助于舒张功能受损程度的判断,优于传统的血流多普勒法,为又一无创检测左室舒张功能的新方法。

Study of left ventricular diastolic function in hypertensive patients by quantitative tissue velocity imaging and strain rate imaging

Objective: To probe the value of peak velocity and strain rate of mitral annulus in assessing left ventricular diastolic function during early and late diastolic period. Methods: Tissue velocity curve and strain rate curve of mitral annulus were obtained in apical four-chamber view from 44 hypertensive patients and 20 normal subjects, peak velocity(Ve, Va) and strain rate(e, a) in diastolic period were measured respectively. The mean peak velocity(EVe, EVa) and ratio(EVe/EVa), the mean peak strain rate(Ee, Ea) and ratio(Ee/Ea) were calculated. Peak flow velocity(E, A) and ratio(E/A) of mitral valve orifice were measured by Doppler and compared. Results: Compared with control group, EVe, EVe/EVa and Ee, Ee/Ea decreased significantly in hypertensive patients, and the values in hypertrophy group(LVH group) were even lower than those of non-hypertrophy group(non-LVH group) in hypertensive patients, while EVa raised significantly, there was high significant correlation between Ee/Ea and EVe/EVa(rs'=0.890, P<0.001), and both of them were much more sensitive to left ventricular diastolic dysfunction than E/A(P<0.001). Conclusions: Quantitative tissue velocity imaging and strain rate imaging can quantify mitral annulus velocity and strain rate in hypertensive patients quickly and properly. It can also show the change of left ventricular diastolic function and help to evaluate the degree of left ventricular dysfunction. It is a new method in assessment of left ventricular diastolic function, which is better than Doppler flow velocity.