Quantification of Pulsatility During Mechanical Circulatory Support

In order to meaningfully compare different perfusion modes (pulsatile vs. non-pulsatile flow) or different types of pulsatile flow (diminished or physiological pulsatility) during mechanical circulatory support (MCS), a precise quantification of pressure and flow waveforms is necessary. To date, pulse pressure is commonly used in the literature as a measurement of pressure waveforms. However, pulse pressure is inadequate as the generation of pulsatile flow highly depends on the energy gradient, rather than the pressure gradient alone. Therefore, hemodynamic energy terms, including energy equivalent pressure (EEP), surplus hemodynamic energy (SHE), and total hemodynamic energy (THE), should be included in order to accurately compare different perfusion modes or different types of pulsatility. This chapter covers several mathematical formulas to quantify pulsatile and non-pulsatile waveforms during acute and chronic MCS.