速度向量成像与组织多普勒成像评价慢性心力衰竭患者左心室应变的对比研究

Velocity vector imaging and tissue doppler imaging in evaluating left ventricular strain in patients with chronic heart failure:a comparative study

目的探索速度向量成像(VVI)用于评价慢性心力衰竭(CHF)患者左心室收缩期应变的可行性,比较VVI与组织多普勒成像(TDI)的差别。方法入选CHF患者30例(CHF组),左心室射血分数(LVEF)为0.35±0.10。健康者14名(正常组),LVEF为0.69±0.11。同时应用VVI和TDI两种技术采集患者心尖四腔、二腔和长轴的二维超声图像,测量左心室壁12节段射血期内应变(ε_(et))及其达峰时间(TTS)、收缩期峰值应变(ε_(peak))及其达峰时间(TTP),并计算收缩后收缩(ε_(ps)=ε_(peak)-ε_(et))、收缩后收缩指数(PSI=ε_(ps)/ε_(peak))以及TTS和TTP的标准差(TTS-sd和TTP-sd)。结果VVI与TDI测得的ε_(et)(r=0.480)、ε_(peak)(r=0.510)、TTS(r=0.428)、TTP(r=0.234)均呈正相关(P值均<0.001)。TDI及VVI测得的各项指标中,CHF组的ε_(et)、ε_(peak)均显著低于正常组(P值分别<0.05、0.01);CHF组的TTS-sd均显著长于正常组(P值分别<0.05、0.01),且VVI较TDI测量离散度更小(P<0.05)。结论VVI技术可以准确评价CHF患者左心室收缩期应变,其测量结果与TDI高度相关。因VVI技术较TDI离散度小,非角度依赖,操作简便,具有一定的临床应用潜力。

Objective To discuss the feasibility of using velocity vector imaging （VVI） for evaluation of left ventricular systolic strain （LVSS） in patients with chronic heart failure （CHF）, and to compare the results with those of tissue Doppler imaging （TDI）. Methods Thirty CHF patients （LVEF being 0.35±0.10） and 14 normal controls （LVEF being 0.69 ±0.11） were included in the present study. Both VVI and TDI techniques were applied to obtain the 2-D images of apical 4-, 2-chamber and long axis views. Ejection time strain （εet）, peak systolic strain（εpeak）, time to peak εet （TTS）, and time to peak εpeak （TTP） were measured at 6-basal and 6-mid segments of LV. Post systolic strain（εps = εpeak -εet） , post systolic index（PSI = εps/εpeak） , standard deviation of TTS （TTS-sd） and TTP （TTP-sd） were calculated. Results The measurements of εet （r = 0. 480）, εpeak（r = 0. 510）, TTS（ r = 0. 428）, and TTP（ r = 0. 234） by VVI were positively Correlated with those by TDI （all P〈0. 001）. Compared with normal controls, the εet and εpeak were significantly reduced in CHF patients by both VVI and TDI （P 〈0. 05 or 0. 01）. TTS-sd was significantly longer in CHF group than that in the normal control group （P〈0.05 or 0.01）. Conclusions VVI can accurately evaluate the LVSS in CHF patients, and the result is highly correlated with those of the TDI. VVI has smaller dispersion degree than TDI; it is independent of the angle and is easy-to-perform, making it clinically valuable.