连续波多普勒超声心动图评价左心舒张功能的实验研究——无创测定等容舒张期时间常数(τ)的准确性  

An experimental study of assessment of left ventricular diastolic function by continuous wave Doppler echocardiography: accuracy of non invasive measurement of time constant Tau

作　　者：周晓东[1] 钱蕴秋[1] 盐田隆弘 戴卫.桑 

机构地区：[1]第四军医大学西京医院超声科,西安710032 [2]美国俄勒冈州卫生科技大学先心病中心

出　　处：《中华超声影像学杂志》1999年第6期364-367,共4页Chinese Journal of Ultrasonography

摘　　要：目的　对比研究由主动脉返流频谱得到的时间常数Ｔａｕ（Ｔａｕ－ＡＲ）和心导管根据左室压力曲线得到的时间常数（τ）的相关性， 评估血流动力学参数和返流容积对Ｔａｕ－ＡＲ的影响。方法　实验动物选用绵羊６只， 体重２２～４３ ｋｇ（平均３３ ｋｇ）， 手术直视下造成（在４个月前）慢性主动脉瓣返流（ＡＲ）。采用药理学方法获得２２种不同的血流动力学状态。连续波多普勒（ＣＷ）测定ＡＲ并根据ＡＲ频谱计算τ（Ｔａｕ－ＡＲ或Ｔａｕ－ＣＷ）， 即从ＡＲ开始到最大ＡＲ速度的（１－ １／ｅ）１／２点的间期为ＣＷ－Ｔａｕ。结果　２２种不同血流动力学状态下， 心导管测定的τ为３２～７５ ｍ ｓ， 平均（４９．１±９．１） ｍ ｓ， 连续波多普勒测定的Ｔａｕ－ＣＷ 为２５～７３ｍ ｓ， 平均（４４．８±８．９）ｍ ｓ， 两者相关性良好（ｒ＝ ０．９５， Ｐ＜ ０．００１）。Ｔａｕ－ＣＷ 与主动脉返流容积呈中度相关， 与返流分数、最大返流量无明显关系。结论　Ｔａｕ－ＣＷ 与心导管所测得的τ相关良好， 它不受心率、返流量和返流分数等血流动力学指标影响， 是一种简便。Objective To compare the relationship between measurement of the time constantly derived from aortic regurgitant velocity spectra (Tau AR) and catheter derived time constant, and to evaluate the effects of hemodynamic flow states and regurgitant volumes on the Tau AR. Methods Six sheep weighing from 22 to 43 kg (mean 33 kg) were studied. A chronic aortic regurgitation (AR) was created surgically while the aortic valve was directly visualized. Twenty two hemodynamically different states were obtained pharmacologically and AR and the time constant derived from continuous wave (CW) Doppler AR velocity spectra (Tau AR or Tau CW) was examined . The time interval from the onset of AR to the point at (1-1/e) 1/2 of the maximal aortic regurgitant CW Doppler velocity was obtained as an estimate of the Tau AR. Results\ Results\ For the 22 different stages hemodynamically analyzed, the catheter derived Tau ranged from 32 to 75 ms [mean (41.9±9.1)ms], and Tau CW from 25 to 73 ms [mean(44.8±8.9)ms]. A good correlation was found between Tau CW and the catheter derived time constant ( r =0.95, P <0.001). There was mild correlation between the CW derived Tau and regurgitant stroke volume( r = 0.60 ). No relationship was found between Tau CW and regurgitant fraction or regurgitant peak flow rate ( r =0.33, 0.36, respectively). Conclusions The time constant Tau can be measured by CW Dopper from aortic regurgitant velocity spectra. This measurement is simple, noninvasive, and it is a conveniently available index for assessment of LV relaxation.

关 键 词：左心室功能 超声心动图 实验 

分 类 号：R540.45[医药卫生—心血管疾病]