Left ventricular hemodynamics with an implanted assisting device: an in-vitro PIV study

A left ventricular assist device (LVAD) is a mechanical pump implanted in heart failure patients to help the impaired left ventricle (LV) pump blood throughout the body. The LVAD continuously takes blood from the LV and delivers it to the aorta, thus decreasing the LV load. Getting a LVAD, however, involves several risks such as blood clot formation due to the presence of the pump and the modified fluid dynamics. In this work, the modified ventricular hemodynamics due to LVAD implantation is studied in-vitro using an elastic ventricle produced by transparent silicone. The ventricle is incorporated (with artificial mitral and aortic valves) into a pulse duplicator setup, which prescribes realistic pulsatile inflow/outflow to mimic a weak ejection fraction (EF) of about 20%. Thereafter, a continuous axial pump is connected at the LV’s apex to mimic a LVAD and its effect on the ventricular hemodynamics is investigated as a function of the pump flow suction. Using particle image velocimetry (PIV), we observe that the continuous pump flow effectively provides unloading on the LV and yields the EF to increase.  However, proper recirculation at the apex and blood sweeping of the myocardium walls does not show much improvement under varying velocities of the continuous flow pump.