Calculation of left ventricular diastolic time constant (Tau) in dogs with aortic regurgitation using continuous-wave Doppler spectra.

Autor:	Fan CZ; Department of Ultrasound, Peking University International Hospital, Beijing, China.; Department of Ultrasound, Beijing Chao-Yang Hospital, Capital Medical University, Beijing, China., Sun J; Department of Ultrasound, Peking University International Hospital, Beijing, China.; Cardiovascular Department, Shannxi Province Crops Hospital of Chinese People's Armed Police Forces, Xi'an, China., Zheng HN; Department of Ultrasound, Peking University International Hospital, Beijing, China., Wen CY; Department of Ultrasound, Peking University International Hospital, Beijing, China.
Jazyk:	angličtina
Zdroj:	Journal of geriatric cardiology : JGC [J Geriatr Cardiol] 2021 Apr 28; Vol. 18 (4), pp. 252-260.
DOI:	10.11909/j.issn.1671-5411.2021.04.007
Abstrakt:	Objective: To investigate a new noninvasive method for calculating left ventricular diastolic time constant (Tau) through a continuous-wave aortic regurgitation Doppler spectrum. Methods: 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). Results: There is no significant difference between Tau-D and Tau-c (45.95 ± 16.90 ms and 46.81 ± 17.31 ms, respectively; P > 0.05). Correlation analysis between Tau-c and Tau-D suggested a strong positive relationship ( r = 0.97, P = 0.000). A Bland-Altman plot of Tau-c and Tau-D revealed fair agreement. Conclusions: This new calculation method is simple, convenient, and shows a strong positive relationship and fair agreement with the catheter method. (Copyright and License information: Journal of Geriatric Cardiology 2021.)
Databáze:	MEDLINE
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