EchocardiographyExercise StressMiscEchocardiography
Aortic Valve Velocity RatioLV EF (Modified Quinones Equation)Myocardial Performance Index (RV)
AVA (Continuity Equation VTI)LV EF (Simplified Quinones Equation)PCWP by E/Ea (Nagueh Formula)
AVA (Continuity Equation VMax)LV Fractional ShorteningPISA (Mitral regurgitation)
dP/dt (LV contractility)LV Mass and LV Mass IndexPISA (Mitral stenosis)
dP/dt (RV contractility)Mitral valve area (PHT)Qp/Qs
Left atrial pressure (MR)Mitral Valvuloplasty Score (MGH)RVSP (TR)
LA Volume (Biplane Method)Modified Bernoulli EquationStroke Volume, Cardiac Output
LV EF (Dumesnil Method)Myocardial Performance Index (LV)
Next

Modified Bernoulli Equation

Calculation


V1 m/s
V2 m/s


∆P mmHg
Calculate

Clear
Top

Information

Simplified formula for converting velocity difference obtained by spectral Doppler to instantaneous pressure gradient.

This clinical equation has been derived from the more complex Bernoulli equation by assuming that viscous losses and acceleration effects are negligible and by using an approximation for the constant that relates to the mass density of blood, a conversion factor for measurement units.

In addition, the simplified Bernoulli equation assumes that the proximal velocity can be ignored, a reasonable assumption when velocity is <1 m/s because squaring a number <1 makes it even smaller. When the proximal velocity (V1) is over >1.5 m/s or the aortic velocity (V2) is <3.0 m/s, the proximal velocity should be included in the Bernoulli equation.

∆P = P2-P1 = 4(V22 – V12)

Variable Definition
V1 Proximal velocity (m/s)
V2 Distal velocity (m/s)
ΔP Instantaneous pressure gradient (mmHg)

References

Baumgartner H, et al. Echocardiographic assessment of valve stenosis: EAE/ASE recommendations for clinical practice. J Am Soc Echocardiogr. 2009 Jan;22(1):5.
Requarth JA, et al. In vitro verification of Doppler prediction of transvalve pressure gradient and orifice area in stenosis. Am J Cardiol 1984;53(9):1369-73.
Information
Illustrations

Top

This calculator has been viewed 92686 times.

Powered by USquareSoft

Author: Dr. Chi-Ming Chow Developer: Edward Brawer Illustrator: Ellen Ho
Copyright © 2005-2011 CardioMath, All Rights Reserved.


Disclaimer: The calculators provided are not meant to be a substitute for professional advise and are not to be used for medical diagnosis. All calculations must be confirmed before clinical use or diagnostic purposes by qualified medical professionals. The authors make no claims of the accuracy of the information contained herein. The authors make no claims whatsoever, expressed or implied, about the authenticity, accuracy, reliability, completeness or timeliness of the material, software, text, graphics and links given. In no event shall the authors, its suppliers, affiliates or any third parties be liable in any manner whatsoever for any damage arising upon use of any information provided.