# Reduced-order modeling of left ventricular flow subject to aortic valve regurgitation

## TL;DR

This paper develops and evaluates reduced-order models using POD and DMD to simulate healthy and diseased left ventricular blood flow, specifically focusing on aortic regurgitation, to improve understanding and modeling of cardiac fluid dynamics.

## Contribution

It introduces the first application of POD and DMD for modeling left ventricular flow in both healthy and aortic regurgitation conditions, providing accessible reduced-order models.

## Key findings

- POD and DMD effectively reconstruct intraventricular flow data.
- Reduced-order models capture key flow features in health and disease.
- Models are made publicly available for further research.

## Abstract

The present focus of heart flow studies is largely based on flow within the left ventricle and how this flow changes when subject to disease. However, despite recent advancements, a simple tractable model of even healthy left ventricular flow has not been produced and made available. Reduced-order modeling techniques, such as proper orthogonal decomposition (POD) and dynamic mode decomposition (DMD), offer an effective means of expressing the large datasets obtained from experiments or numerical simulations using low-dimensional models. While POD and DMD are often used to identify coherent structures in fluid dynamics, their use as a modeling tool has not found much merit in the cardiovascular flow community. In this work, we use POD and DMD to construct reduced-order models for a healthy left ventricular flow as well as for that under the influence of a particular disease shown to exhibit rich and unique intraventricular fluid dynamics, namely, aortic regurgitation (a leaking aortic valve). The performance of the two methods in reconstructing the intraventricular flows and derived quantities is evaluated, and the selected reduced-order models are made available.