In-vitro investigation of the hemodynamics of the Left Ventricle supported by a Left Ventricular Assist Device

Use of Left Ventricular Assist Devices (LVAD) therapy has grown over the last decade with increased prevalence of advanced heart failure coupled with stagnant heart donor availability. Despite recent advances in LVAD design, thromboembolic and hemorrhaging events remain the primary cause of mortality and morbidity. We investigate unfavorable intraventricular hemodynamics around the LVAD inflow canula and apical region. Particle Image Velocimetry was used to analyze the flow inside a patient-specific LV phantom implanted with an LVAD. A pulsatile pump programmed to simulate the reduced native output of the failing LV was used to circulate an index of refraction matched blood-mimicking fluid through the LV. Clinically relevant parameters such as pulsatility and preload and afterload pressures were changed to understand their role in LV hemodynamics. Flow patterns conducive to intraluminal thrombus formation were identified. Specifically, stagnation and recirculation zones were observed in the apical region. These patterns are strongly influenced by the pulsatility and by the preload and afterload pressures. Such unfavorable hemodynamics may explain the incidence of thrombosis even in third generation optimized pumps, via platelet activation, aggregation and thrombus formation.