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

Pulmonary-Systemic Flow Ratio (Qp/Qs)

Calculation


LVOT mm
LVOT VTI cm
RVOT mm
RVOT VTI cm


Qp/Qs
Calculate

Clear
Top

Information

Qp/Qs can be estimated by using 2-D echo and spectral Doppler measurements in patients who have intra- or extra-cardiac shunts e.g. atrial or ventricular septal defects.

Qp =
RVOT VTI * π *
RVOT
2
2
Qs =
LVOT VTI * π *
LVOT
2
2
Qp/Qs Ratio = Qp/Qs

Variable Definition
Input
LVOT Left ventricular outflow tract diameter (mm)
LVOT VTI RVOT subvalvular velocity time integral (cm)
RVOT Left ventricular outflow tract diameter (mm)
RVOT VTI RVOT subvalvular velocity time integral (cm)
Output
Qp/Qs Pulmonary-Systemic Shunt Ratio

References

Sanders SP, et al. Measurement of systemic and pulmonary blood flow and Qp/Qs ratio using Doppler and two-dimensional echocardiography. Am J. Cardiol, 51:952, 1983.
Information
Illustrations


Top

This calculator has been viewed 242299 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.