Why are values for the same hemodynamic parameters different in the Blood Pressure Module and PV-Loop Module analyses?

These discrepancies are related to differences in the methods the two modules use to calculate the derivative of a signal, and will affect all of the calculations for these modules to some degree. The PV Loop Module uses a 2 point derivative calculation method, which is the same method used by Millar Instruments' PVAN software. This is to ensure that the PV Loop Module's results will match results previously obtained with the PVAN software. The Blood Pressure Module uses a 3 point derivative calculation method.

Neither method is incorrect. However, we recommend using only one module's calculated results. Doing so ensures that any variation is the result of experimental changes and not differences in calculation methods.