How to calculate Left Atrial Pressure by Color M Mode (CMM).
Obtain a PWD of the long axis view of the mitral valve. The PWD will yield a E and A wave. The maximum E wave velocity, Emax should be measured and entered above.
Obtain a Color M-Mode scan of the left ventricle. Obtain a color flow doppler of the left ventricle in the midesophageal view. While in color mode, add the M-Mode mode to the scan and place the scan line down the center of the left ventricle. On the Color M-Mode scan the propagation of flow shows an early passive filling (E wave) and late active filling (A wave) of the left ventricle. Using the caliper function measure the slope of the first aliasing velocity of the E wave. Enter the slope (Vp) or velocity of propagation.