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

Bai X - Open Cardiovasc Med J (2008)

Bottom Line: 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.

View Article: PubMed Central - PubMed

Affiliation: Henderson Research Center, McMaster University, Hamilton, Ontario, Canada. xufangbai@yahoo.com

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.

No MeSH data available.


Related in: MedlinePlus

Schematic description of measurement of time intervals (t1-t3) and (t1-t2) on the descending limb of mitral regurgitation continuous-Doppler spectrum.
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Figure 1: Schematic description of measurement of time intervals (t1-t3) and (t1-t2) on the descending limb of mitral regurgitation continuous-Doppler spectrum.

Mentions: Three points, (t1, 1m/s), (t2, 2m/s) and (t3, 3m/s), are chosen on the descending limb of the mitral regurgitation continuous-wave Doppler velocity curve (Fig. 1), and substituted into Eq. (6) respectively, which can come across the following three equations:


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

Bai X - Open Cardiovasc Med J (2008)

Schematic description of measurement of time intervals (t1-t3) and (t1-t2) on the descending limb of mitral regurgitation continuous-Doppler spectrum.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2570574&req=5

Figure 1: Schematic description of measurement of time intervals (t1-t3) and (t1-t2) on the descending limb of mitral regurgitation continuous-Doppler spectrum.
Mentions: Three points, (t1, 1m/s), (t2, 2m/s) and (t3, 3m/s), are chosen on the descending limb of the mitral regurgitation continuous-wave Doppler velocity curve (Fig. 1), and substituted into Eq. (6) respectively, which can come across the following three equations:

Bottom Line: 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.

View Article: PubMed Central - PubMed

Affiliation: Henderson Research Center, McMaster University, Hamilton, Ontario, Canada. xufangbai@yahoo.com

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.

No MeSH data available.


Related in: MedlinePlus