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. 2008:2:9-11.
doi: 10.2174/1874192400802010009. Epub 2008 Apr 25.

Calculation of left ventricular relaxation time constant-Tau in humans by continuous-wave Doppler

Xufang Bai  1
Affiliations

Calculation of left ventricular relaxation time constant-Tau in humans by continuous-wave Doppler

Xufang Bai. Open Cardiovasc Med J. 2008.

Abstract

Left ventricular relaxation time constant, Tau, is the best index to evaluate left ventricular diastolic function, but the measurement is only available traditionally in catheter lab. In Echo lab, several methods of non-invasive measurement of Tau have been tried since 1992, however almost all the methods are still utilizing the same formula to calculate Tau as in catheter lab, which makes them inconvenient, time-consuming and sometimes not very accurate. Based on Weiss' formula and simplified Bernoulli's equation, a simple method is developed by pure mathematical derivative to calculate Tau by continuous-wave Doppler in patients with mitral regurgitation.

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Figures

Fig. (1)
Fig. (1)
Schematic description of measurement of time intervals (t1-t3) and (t1-t2) on the descending limb of mitral regurgitation continuous-Doppler spectrum.
Fig. (2)
Fig. (2)
The curve derived from Eq. (9) shows the relation of (t1-t3)/(t1-t2) and LAP.
Fig. (3)
Fig. (3)
The curve derived from Eq. (10) shows the relation of Tau/(t1-t3) and LAP.
See this image and copyright information in PMC

References

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