Fan Chun-Zhi, Sun Jing, Zheng Hai-Ning, Wen Chao-Yang
Department of Ultrasound, Peking University International Hospital, Beijing, China.
Department of Ultrasound, Beijing Chao-Yang Hospital, Capital Medical University, Beijing, China.
J Geriatr Cardiol. 2021 Apr 28;18(4):252-260. doi: 10.11909/j.issn.1671-5411.2021.04.007.
To investigate a new noninvasive method for calculating left ventricular diastolic time constant (Tau) through a continuous-wave aortic regurgitation Doppler spectrum.
According to ultrasound guidance, twenty-four animal models (beagles) of aortic regurgitation and acute ischemic left ventricular diastolic dysfunction were created. The left ventricular diastolic function was manipulated with dobutamine or esmolol and fifty-nine hemodynamic stages were achieved. Raw audio signals of the continuous-wave Doppler spectra were collected, and new aortic regurgitation Doppler spectra were built after reprocessing by a personal computer. The updating time of the spectral line was 0.3 ms. The new Doppler spectra contour line was automated using MATLAB (MATrix LABoratory, MathWorks, Natick, MA, USA), and two time intervals, (t2-t1) and (t3-t1) were measured on the ascending branch of the aortic regurgitation Doppler spectrum. Then, the two time intervals were substituted into Bai's equations, and Doppler-derived Tau (Tau-D) was resolved and compared with catheter-derived Tau (Tau-c).
There is no significant difference between Tau-D and Tau-c (45.95 ± 16.90 ms and 46.81 ± 17.31 ms, respectively; > 0.05). Correlation analysis between Tau-c and Tau-D suggested a strong positive relationship ( = 0.97, = 0.000). A Bland-Altman plot of Tau-c and Tau-D revealed fair agreement.
This new calculation method is simple, convenient, and shows a strong positive relationship and fair agreement with the catheter method.
研究一种通过连续波主动脉反流多普勒频谱计算左心室舒张时间常数（Tau）的新的非侵入性方法。
在超声引导下，建立24只主动脉反流和急性缺血性左心室舒张功能障碍的动物模型（比格犬）。用多巴酚丁胺或艾司洛尔控制左心室舒张功能，共获得59个血流动力学阶段。收集连续波多普勒频谱的原始音频信号，经个人计算机重新处理后构建新的主动脉反流多普勒频谱。频谱线的更新时间为0.3毫秒。使用MATLAB（矩阵实验室，美国马萨诸塞州纳蒂克市MathWorks公司）自动生成新的多普勒频谱轮廓线，并在主动脉反流多普勒频谱的上升支上测量两个时间间隔，即（t2 - t1）和（t3 - t1）。然后，将这两个时间间隔代入白氏方程，求解多普勒衍生的Tau（Tau - D），并与导管衍生的Tau（Tau - c）进行比较。
Tau - D与Tau - c之间无显著差异（分别为45.95±16.90毫秒和46.81±17.31毫秒；P>0.05）。Tau - c与Tau - D的相关性分析显示出强正相关关系（r = 0.97，P = 0.000）。Tau - c和Tau - D的布兰德-奥特曼图显示出良好的一致性。
这种新的计算方法简单、方便，与导管法显示出强正相关关系和良好的一致性。
