**Abstract**

Aortic insufficiency (AI) is a common complication that increases morbidity and mortality in patients with left ventricular assist devices (LVAD). Significant AI during LVAD support creates a substantial regurgitant flow loop, negatively affecting cardiac recovery and exposing blood to longer residence time and higher shear stress. The mechanism of AI development and progression is linked to a lack of aortic valve opening, which alters the valvular tissue mechanics. Pre-existing AI also worsens following LVAD implantation, interfering with the pump benefits. This chapter will evaluate AI development with LVAD support compared with naturally occurring AI and present the features, mechanisms, and links to clinical treatment options.

**Keywords:** aortic valve, insufficiency, LVAD, flow, aortic insufficiency (AI)
