How to calculate a IMP.

Step 1: A CWD of the LVOT, RVOT, MV or TV. The index of myocardial performance compares mechanical systole (A) to the ejection time period (B). Alternatively, the ejection period for a mitral/tricuspid regurgitant jet can be used for the ejection period (B) since, for mitral/tricuspid regurgitation, the ejection period and the mechanical systolic period are the same. As the ejection time period converges on the mechanical systolic period, the ejection force is decreasing.