Calculation of left ventricular relaxation time constant (Tau) in dogs with mitral regurgitation by continuous-wave Doppler
10.3877/cma.j.issn.1672-6448.2017.01.016
- VernacularTitle:二尖瓣反流连续多普勒频谱评价犬左心室松弛时间常数Tau
- Author:
Jing SUN
1
;
Chunzhi FAN
;
Jianping DOU
;
Chaoyang WEN
Author Information
1. 武警陕西总队医院心内科
- Keywords:
Continuous Doppler ultrasound;
Mitral regurgitation spectrum;
Ventricular relaxation time constant
- From:
Chinese Journal of Medical Ultrasound (Electronic Edition)
2017;14(1):67-71
- CountryChina
- Language:Chinese
-
Abstract:
Objective To explore the new method for noninvasively measuring the time constant of left ventricular relaxation (Tau) in animals with mitral regurgitation by continuous-wave Doppler.Methods The acute ischaemic left diastolic heart failure with mitral regurgitation was produced in 9 dogs.Dobutamine hydrochloride or esmolol hydrochloride had been applied to change the hemodynamic states.In different hemodynamic states,left ventricular pressures,left atrial pressures,curves of dP/dt and continuous-wave mitral regurgitant spectra were synchronously recorded.Doppler spectra were laterly processed through Matlab workstation.Paired t-test was used to compare the difference between Tau-catheter (Tau-c) and Tau-doppler ultrasound (Tau-d),and the correlation between Tau-c and Tau-d was analyzed by Pearson correlation analysis.Results Thirty-nine hemodynamic status had been obtained in 9 dogs.Tau-c was 21.03-78.45 ms and the average was (48.76± 17.60) ms.Tau-d was 21.24-94.60 ms and the average was (49.33 ± 18.79) ms.There was no significant difference (t=0.353,P=0.726) between Tau-d and Tau-c.The correlation analysis between Tau-d and Tau-c suggested a strong positive relationship with the correlation coefficient (r=0.85,P ＜ 0.001).Conclusions The dog aortic regurgitation model under ultrasound guidance is less traumatic.The method of inducing left ventricular diastolic dysfunction by repeatedly injecting microspheres into the left coronary sinus is safe and reliable.Choosing three points (t1,1 m/s;t2,2 m/s;t3,3 m/s) in aortic regurgitant velocity spectrum and putting them into the corresponding formula,we can obtain Tau,which had a good correlation with the catheter-derived Tau.
