Aortic valve opening in mock-loop with continuous-flow left ventricular assist device

Abstract

The appropriate opening of aortic valves is crucial for heart failure (HF) patients with left ventricular assist devices (LVADs). Nevertheless, up to the present time, aortic valve monitoring has not been performed in discharged patients. In this study, a mock-loop platform was developed to investigate the aortic valve performance in LVAD patients. An additional sluice valve was placed next to the aortic valve that when the sluice valve is manually closed, the aortic valve will remain closed; when the sluice valve is open, the aortic valve is opened or closed upon the pressures. The results showed that when the LVAD speed was below 2600 rpm, the aortic valve can be intermittently opened, while when the LVAD speed was over 2600 rpm, the aortic valve was persistently closed. The left ventricular end-systolic pressure (LVESP) was found to be an indicator of aortic valve closure that, upon the aortic valve closure LVESP suddenly decreased. The LVESP is suggested for future monitoring the status of the aortic valve for patients with implanted LVADs. The effects of heart failure (HF) degrees, circulation resistance, and aortic compliance on aortic valve closure were further studied. The results revealed that LVAD implantation in patients with early HF degrees will help to avoid persistent aortic valve closure.