多普勒超声法测定心输出量存在的误差和校正方法

Influence of cardiac motion on the value of the stroke volume obtained with Doppler method and correction method

目的探讨心脏运动对多普勒速度时间积分(VTI)和每搏量(SV)的影响及其校正的方法。方法于心尖五腔观观察38例正常健康成人心脏运动多普勒VTI(VTIc)及其与主动脉瓣口血流速度曲线VTI(VTIb)的关系;分别计算受心脏运动影响校正前、后的每搏量(SVb、SVb+c),并与临床上公认的Simpson法测量的每搏量(SVs)比较。结果人体心脏运动的VTI占相应瓣口血流VTI的(16.8±3.4)%。SVb、SVb+c分别与SVs作相关分析,r分别为0.74和0.80;两个相关系数t检验的t值为6.601(P<0.001)。结论超声心动图仪所测流速曲线VTI与实际主动脉瓣口血流的VTI存在着误差,而据此VTI计算的SV误差更明显;由心脏运动校正后的VTIb+c计算SVb+c值较校正前更精确。

Objective To investigate the influence of the Doppler frequency shift signals produced by cardiac motion on the velocity time integral（VTI） and the value of stroke volume（SV） and the correction method. Methods The velocity time integral（VTIc） of Doppler frequency shift by cardiac motion and the Doppler blood flow spectrum velocity-time integral（VTIb） at aortic valve in apical five-chamber view were measured in 38 health adults and the SV of before and after rectified by cardiac-motion（SVb, SVb ＋ c） was calculated and compared with the SVs by Simpson＇s formula. Results VTIc accounted for VTIb （16.8 ± 3.4） %. Correlation analysis of SVb,SVb ＋ c and SVs respectively, r was 0.74 and 0.80; P〈0. 001 by two correlation coefficient t test. Conclusions The VTI of Doppler blood flow spectrum recording in screen has an error compared with the real VTI through the aortic valve annulus. The SV calculated by VTIb 4- c （after cardiac-motion rectified） is more accurate than that before rectified by Doppler＇s methods.