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| How
to get an PVA by Velocity Ratio. |
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| Step
1: Measure the RVOT diameter in centimeters.
The optimal view is a maximally zoomed view
of the upper esophageal ArchSAX/PVLAX or the
RVIO view. The gain and compress should be set
so the endomyocardial wall of the RVOT is clearly
discernable. Freeze the display and use the
trackball to cycle thru the cardiac cycle to
the mid-ejection period when the RVOT is at
it's maximal diameter. Using the calipers, measure
from intimal wall to intimal wall just proximal
to the aortic valve. Enter the RVOT diameter
above. |
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| Step 2:
Obtain a continuous wave doppler of the pulmonic
valve. The optimal view is the deep transgastric
PVLAX view or the upper esophageal ArchSAX/PVLAX
view. The latter view is preferable if obtainable.
Once the view is obtained turn on the CWD and
use the track ball to move the CWD line to the
pulmonic valve. A doppler profile of the aortic
valve should be displayed with high velocities
in pulmonic stenosis. If a poor or low velocity
doppler wave form is displayed reposition the
view and move the CWD line thru out the valve.
The CWD must be parallel to the stenotic jet
to pick up the maximal velocity and obtain a
good doppler wave form. After a good doppler
wave form is obtained look at the morphology
of the waveform and note it. Using the
tracing feature, use the trackball and trace
the doppler profile. The maximum velocity, Vmax,
for the AV should be enter above. |
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| Step
3: Obtain a pulse wave doppler of the RVOT.
The optimal view is the deep transgastric PVLAX
view or the upper esophageal ArchSAX/PVLAX view.
The latter view is preferable if obtainable.
Once the view is obtained turn on the PWD and
use the track ball to move the PWD line to the
RVOT and place the sample volume just proximal
to the pulmonic valve. The sample volume should
be at the same location where the RVOT diameter
was measured. A doppler profile of the RVOT
should be displayed with normal velocities in
the RVOT. If a poor or low velocity doppler
wave form is displayed reposition the view and
move the PWD line thru out the RVOT. The PWD
must be parallel to the RVOT jet to pick up
the maximal velocity and obtain a good doppler
wave form. After a good doppler wave form is
obtained look at the morphology and the maximal
velocity of the waveform and note it. Using
the tracing feature, use the trackball and trace
the doppler profile. The maximum velocity, Vmax,
for the LVOT should be entered above. |
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