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How
to get a Regurgitant Volume in Pulmonary
Regurgitation. |
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Step
1: Measure the Diameter of the RVOT.
The diameter can be of the RVOT should
be obtained from the midesophageal RVIO
view, in mid systole, and under the zoom
mode. The view of the RVOT should
not be an obtuse angle view. The
pulmonic valve leaflets should be clearly
seen. The zoom mode will decrease
the error present in the calculation.
Since the RVOT diameter changes throughout
systole, the mid systole measurement should
be obtained. |
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Step
2: Obtain a VTI of the RVOT.
The VIT of the RVOT is obtained from a
PWD of the RVOT. The PWD of the
RVOT should be obtained at the same locatio n
as the RVOT diameter measurement.
The PWD beam should not be off more than
15º from parallel to the RVOT flow.
After tracing the flow on the echocardiographic
machine, a VTI of the PWD tracing will
be calculated. A continuous wave
doppler (CWD) of the RVOT could be obtained,
but, since the CWD introduces ambiguity
into the equation and since flows in the
RVOT rarely exceed the aliasing velocity
of the pulse wave doppler, PWD is the
best measurement mode. However,
in aortic regurgitation, there is excessive
flow, so aliasing may occur. Therefore,
CWD may be required to be able to trace
the whole flow profile. |
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Step
3: Obtain a Tricuspid Valve Diameter.
The area of the tricuspid valve can be
calculated from this measurement.
This enter some inaccuracy into the equation
since the mitral valve is not a circle
(it is oval). Therefore, the aortic
valve could be used instead. This
measurement is to be used to generate
a value that represents normal forward
flow in the cardiac cycle. |
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Step
4: Obtain a Tricuspid Valve
VTI. Using the PWD mode,
trace the envelope of the entire (E wave
and A wave) flow profile of the tricuspid
valve. |
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