Maximal Elastance (Emax) is often referred to as End-Systolic Elastance (Ees) and is equal to the slope of the end-systolic pressure volume relationship (ESPVR). Emax can be determined by first altering the preload through IVC occlusion. Then, select your occlusion data and analyze your selection with the PV Loop Module. Simply use the Loop View and make sure ESPVR is checked. The equation will be something like this:
ESPVR: Pes = 14.386*Ves - 198
Maximum Elastance for this case = 14.386
Note: A linear regression best fit line for occlusion data in this case is in the form of a straight line: y = mx + b, where m = slope and y = y-int.