A study of hemodynamic residence time in the left ventricle in surgically-implanted and catheter-based Left Ventricular Assist Devices.

Left ventricle assist devices (LVADs) are pumps implanted in patients with advanced heart failure to support the failing left ventricle. Stagnation inside the Left Ventricle (LV) is associated with thrombosis, which can lead to stroke, the most common cause of mortality and morbidity in this therapy. We study the hemodynamics in the LV implanted with two different types of LVADs (Impella and HeartMate 3) to compare the residence time and areas of stagnation with the two types of pumps. Using a clear silicone LV model and a refraction-index-matched blood surrogate fluid, we study fluorescent dye washout from the LV under physiological conditions. The Impella and HM3 provide the same level of support, and quantitative imaging characterizes the residence time of fluid in the left ventricle under LVAD suction and remnant LV contractility, revealing their respective paradigmatic flow fields. Areas of high residence time are indicative of increased thrombosis risk. This in vitro study aims to shed light into the intraventricular hemodynamics of these differing therapy options, helping clinicians in their choice of treatment. There is need to better characterize the effects of catheter-based LVADs, compared to the longer experience with surgically-implanted LVADs.