Hemodynamics in Aortic Regurgitation Simulated Using a Computational Cardiovascular System Model

The influence of left ventricular and aortic tissue properties on hemodynamics in patients with aortic regurgitation (AR) is unclear. In this study we aim: (1) to assess the capability of the CircAdapt model of the heart and circulation to simulate hemodynamics in AR; (2) to determine the interaction between aortic compliance and AR using CircAdapt. We simulated three degrees of AR by changing the aortic regurgitant orifice area (ROA) with normal and low aortic compliance. The higher the ROA is, the higher the systolic left ventricular and aortic pressures, the lower the diastolic aortic pressures and the higher the diastolic left ventricular pressures are. For low aortic compliance, those effects are exacerbated, but the regurgitant blood volume is decreased. These simulation data show the capability of CircAdapt to simulate hemodynamics in AR, and suggest that patient-to-patient variability in aortic compliance should be taken into account when assessing AR severity using imaging-based hemodynamic metrics.