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How
to get an PVA by PISA. |
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Step
1: Obtain a Zoomed CFD of the PV in the Aortic
Arch SAX or Deep Transgastric view. If there is
a sufficiently stenosed pulmonary valve, a PISA formation
will occur. The distance from the center of
the PISA formation to it's first aliasing velocity
edge (where the color shifts from blue to red) is
the radius of the PISA formation. |
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Step
2: Note the aliasing velocity. The aliasing
velocity is the velocity where if the flow exceeds
this velocity the flow will be displayed with colors
from the opposite scale. |
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Step
3: Obtain a continuous wave doppler (CWD) of the
aortic valve. The CWD of the pulmonary valve
will yield a flow profile where, utilizing the calipers
(or you can trace it) to show the peak velocity.
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Step
4: Obtain an angle of the PISA formation:
The angle at the pulmonary valve is typically 180
degrees, whereas the angle at the mitral valve (for
mitral stenosis calculations) is typically 120 degrees. |
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