Image-Based Whole-Heart Cardiac Flow Simulations in Health and Congenital Heart Disease

TL;DR

This paper introduces a patient-specific, image-based CFD framework for simulating whole-heart intracardiac flow, balancing physiological accuracy with computational efficiency, applicable to both healthy and congenital heart disease cases.

Contribution

It presents a novel machine learning-driven segmentation and mesh propagation method combined with resistive immersed surfaces for realistic valve modeling in cardiac flow simulations.

Findings

Simulations accurately reproduced pressure-volume behavior and valve dynamics.

Flow fields matched 4D-Flow MRI qualitatively and revealed detailed structures.

CHD case showed altered flow patterns and increased viscous dissipation.

Abstract

Intracardiac flow patterns are shaped by the coupled motion of the cardiac chambers and heart valves and provide important information about cardiac function. However, clinical flow imaging remains limited by exam times, noise, resolution, and incomplete details of the three-dimensional flow. Computational fluid dynamics (CFD) can potentially provide detailed flow quantification and predictive insight into treatment outcomes, but clinical translation requires frameworks that reproduce patient-specific measurements while balancing physiological realism, computational cost, and modeling effort. Herein, we present an image-based, patient-specific computational framework for simulating whole-heart intracardiac hemodynamics that balances physiological fidelity with computational efficiency. The framework first employs machine learning-based segmentation and mesh propagation to reconstruct moving cardiac anatomies from time-resolved images. CFD simulations are then performed to resolve blood flow in deforming domains, while resistive immersed surfaces (RIS) are used to model all four cardiac valves with physiologically realistic opening and closing dynamics. The framework was applied to model hemodynamics in a healthy adult and a pediatric patient with complex congenital heart disease (CHD). In the healthy case, the simulations reproduced physiologic pressure-volume behavior, valve timing, and ventricular vortex formation. In the CHD case, simulated chamber and vessel pressures showed agreement with cardiac catheterization measurements. Simulated flow fields were qualitatively consistent with 4D-Flow MRI, while providing higher-resolution visualization of flow structures that were partially obscured by imaging artifacts. Comparison between the healthy and CHD cases further revealed altered diastolic flow organization and elevated normalized viscous dissipation in the CHD heart.