Invasive pressure-volume (PV) loop measurements have the potential to confirm or refute earlier computer simulations and animal studies regarding changes in cardiovascular physiology induced by (veno-arterial) ECMO. PV loop analysis could create a framework for the (ICU-) clinician for VA-ECMO weaning guidance, based on a patient's individual hemodynamic profile. PV loop measurements may, in future, serve as a guide for which patient would benefit most from (prolonged) VA-ECMO support or which patient would require additional LV unloading. Within the context of PLUTO-I, patients on VA-ECMO support who are eligible for weaning from VA-ECMO will undergo biventricular PV loop measurements on different intensities of extracorporeal support.