|
|
|
How
to get an TVA by PISA. |
|
Step
1: Obtain a Zoomed CFD of the TV in the GE or ME
Bicaval view. If there is a sufficiently stenosed
tricuspid 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. |
|
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. |
|
Step
3: Obtain a continuous wave doppler (CWD) of the
tricuspid valve. The CWD of the mitral valve
will yield a flow profile where, utilizing the calipers
(or you can trace it) to show the peak velocity. |
|
Step
4: Obtain an angle of the PISA formation: The
angle at the tricuspid valve is typically 120 degrees,
whereas the angle for the aortic valve (for aortic
stenosis calculations) is typically 180 degrees. |
|
|