Overview
ECMO and Impella add continuous flow, while native ventricular ejection supplies the pulsatile part. Strong support with little native ejection can therefore produce a nearly flat arterial trace around a supported mean pressure.
Impella drains the LV toward the aorta; peripheral V-A ECMO bypasses the lungs and can increase LV loading. The modeled chamber pressures and PV loops respond differently to those configurations.
During ECMO-supported VF or a zero-rate state, vasoactive drugs and sedative vascular effects still change SVR and supported mean pressure. Native ejection remains absent: a pressure rise is not rhythm conversion or restoration of a pulse.
The model is not meant to force every supported tracing to a completely flat line. Residual native ejection, rhythm, loading and support level determine how much pulse remains.