# Material transport in the left ventricle with aortic valve regurgitation

## TL;DR

This study investigates how aortic regurgitation affects blood flow and particle retention in the left ventricle, revealing longer residence times and complex flow structures that may increase clotting risks.

## Contribution

It provides new insights into flow dynamics and particle retention in the left ventricle under aortic regurgitation, highlighting potential risks for thrombus formation.

## Key findings

- Longer particle residence times with moderate regurgitation
- Increased flow frequency components with severity
- Retention of regurgitant inflow for at least one cardiac cycle

## Abstract

This experimental in vitro work investigates material transport properties in a model left ventricle in the case of aortic regurgitation, a valvular disease characterized by a leaking aortic valve and consequently double-jet filling within the elastic left ventricular geometry. This study suggests that material transport phenomena are strongly determined by the motion of the counterrotating vortices driven by the regurgitant aortic and mitral jets. The overall particle residence time appears to be significantly longer with moderate aortic regurgitation, attributed to the dynamics resulting from the timing between the onset of the two jets. Increasing regurgitation severity is shown to be associated with higher frequencies in the time-frequency spectra of the velocity signals at various points in the flow, suggesting nonlaminar mixing past moderate regurgitation. Additionally, a large part of the regurgitant inflow is retained for at least one cardiac cycle. Such an increase in particle residence time accompanied by the occurrence and persistence of a number of attracting Lagrangian coherent structures presents favorable conditions and locations for activated platelets to agglomerate within the left ventricle, potentially posing an additional risk factor for patients with aortic regurgitation.