二维斑点追踪技术评价慢性心力衰竭患者左心室收缩同步性

目的利用二维斑点追踪显像（2D-STI）技术评价慢性心力衰竭患者左室机械运动同步性。方法37例慢性心力衰竭患者，依据左室射血分数（LVEF）分为两组：A组，LVEF≤35％；B组，35％〈LVEF〈50％。35例正常人为对照组（C组）。采集受试者心尖两腔观、三腔观、四腔观及胸骨旁左室短轴观二尖瓣水平、乳头肌水平的清晰图像，用Qlab软件测量各切面二尖瓣水平和乳头肌水平各节段白QRS起点至收缩期峰值应变、应变率的时间，推算左室12节段纵向、径向及圆周应变、应变率不同步参数：达收缩期峰值时间标准差（Tsl-12SD、Tslr-12SD、Tst-12SD、Tsrr-12SD、TSC-12SD、Tscr-12SD）和最大时间差（Tsl-12Dif、Tslr-12Dif、Tsr-12Dif、Tsrr-12Dif、Tsc-12Dif、Tscr-12Dif），比较三组参数。分析LVEF与各参数的相关关系。根据统计学原理，推算C组各参数的不同步界限，计算A、B组各参数的不同步检出率，组内比较各个率值。结果与C组比较，A组各项不同步参数均显著增大（P〈0．05），B组Tsl一12SD、Tsl一12Dif、Tslr-12SD、Tslr-12Dif及Tsr-12SD显著增大（P〈O．05）。病例组各项不同步参数均与LVEF呈显著线性负相关（P〈0．05）。A、B两组内各项参数检出率差异均有统计学意义（均P〈0．05），均以Tsl-12SD的检出率最高。结论2D-STI技术能定量评价慢性心力衰竭患者左室收缩同步性，纵向参数较径向、圆周参数检出不同步的能力更强。

Objective To evaluate the left ventricular mechanical dyssynchrony in patients with chronic heart failure(CHF)by two dimensional speckle tracking imaging(2D-STI).Methods 37 CHF patients were enrolled in this study.According to left ventricular ejection fraction(LVEF),the patienst were classified into two subgroups:group A,LVEF≤ 35 ％;group B,35 ％＜LVEF＜50 ％.35 healthy volunteers constituted the control group(group C).Standard 2D images were acquired in the 2-,3-and 4-apical views as well as the parasternal short-axis views at the level of the mitral valve and papillary muscles.The time to peak-systolic strain and strain rate were measured for each segment in the level of the mitral valve and papillary muscles in Qlab software.Dyssychrony parameters were defined as the standard deviation and the maximal time delay of the time to peak-systolic strain and strain rate for 12 segments.Parameters were compared among the three groups respectively.The correlation between dyssynchrony parameters and LVEF were analysed in CHF patients.The cut-off value of each parameter were derived from group C based on statistical principles.Dyssychrony rate of each parameter were calculated in group A and B,and compared within each group respectively.Results Compared with group C,all the dyssychrony parameters in group A were significant higher(P＜0.05),and part of the parameters(Tsl-12SD,Tsl-12Dif,Tslr-12SD,Tslr-12Dif and Tsr-12SD)in group B were remarkable higher(P＜0.05).Dyssychrony parameters in CHF patients correlated closely with LVEF(P＜0.05).Significant differences among dyssychrony rates were noted in both group A and B(P＜0.05),and Ts1-12SD showed the highest value in both subgroups.Conclusions 2D-STI is useful in quantifying left ventricular systolic dyssychrony in CHF patients,and the longitudinal parameters are more efficient to detect mechanical dyssychrony than the radial parameters and circumferential parameters.