Thromboembolism Is Linked to Intraventricular Flow Stasis in a Patient Supported with a Left Ventricle Assist Device

Abstract

A case report is presented of a left ventricular assist device (LVAD) recipient with a pre-existing thrombus that was removed on LVAD implant but quickly reformed and was removed, reformed again, and ultimately embolized, causing death. The thrombus formed proximal to the left ventricular outflow tract, because of the presence and subsequent repair of a calcified left ventricular infarct which had extruded from the septum. This region is vulnerable to flow stasis during LVAD support as predicted by experimental fluid mechanics studies, because of the lack of opening of the aortic valve. The presence of the repair and the altered flow field contributed to blood stasis and thrombus growth in a positive feedback loop. Although LVADs provide tremendous benefits for patients by reducing the symptoms of heart failure, the accompanying changes have some secondary consequences that remain problematic. One of these is an abnormal intraventricular flow field that decreases washout, especially in the region proximal to the left ventricular outflow tract, which is an area of flow stasis.