Mitral Valve Area by PISA

Mitral Valve Area:
Formula:MVA = (2 * Π r² * VA * α / 180) / Vmax
How to calculate PISA radius from the PISA Arc width and height:

Sometimes it is difficult to determine the radius from the flow convergence formation arc to the center of the valve or the arc. Fortunately, if you can draw a line from one side of the arc to the other (the Arc Width) and then from the center of the line to the edge of the arc perpendicular to the width, the radius can be calculated (and may be more accurate, although not studied) from the arc width and height. Enter the values above and the radius is automatically calculated.

How to get an Mitral Valve Area by PISA.

  1. Obtain a Zoomed CFD of the MV in the mid esophageal view.If there is a sufficiently stenosed mitral 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.
  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.
  3. Obtain a continuous wave doppler (CWD) of the mitral 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.
  4. Obtain an angle of the PISA formation: The angle at the mitral valve is typically 120 degrees, whereas the angle for the aortic valve (for aortic stenosis calculations) is typically 180 degrees.