Boundary-Condition Analysis of an Idealized Left Atrium Model

Area of Science:

• Cardiovascular Science
• Biomedical Engineering
• Fluid Dynamics

Background:

• Atrial fibrillation (AF) is a common arrhythmia leading to thrombus formation in the left atrial appendage (LAA), increasing thromboembolic risk.
• Understanding the fluid dynamics of thrombus formation is crucial for developing effective therapies for AF patients.
• Current Computational Fluid Dynamics (CFD) models require validation with accurate in vivo flow measurements, which are challenging to obtain.

Purpose of the Study:

• To propose and validate an in vitro flow model for studying thrombus formation in the left atrial appendage (LAA).
• To provide detailed velocity field data for validating CFD simulations of blood flow in the human left atrium (LA).
• To establish a benchmark for future development and validation of LA CFD models.

Main Methods:

• Development of an idealized in vitro flow model simulating human left atrial (LA) flow features.
• Utilizing Particle Image Velocimetry (PIV) to obtain detailed velocity field measurements.
• Validation of laminar and Large Eddy Simulation (LES) CFD models against PIV data.
• Parametric study of various boundary conditions used in prior LA CFD literature.

Main Results:

• The in vitro model successfully captured key flow features of the human LA.
• PIV measurements provided detailed, reproducible velocity fields for model validation.
• Validated laminar and LES CFD simulations offer accurate representations of LA blood flow.
• The study generated a valuable dataset for benchmarking LA CFD models.

Conclusions:

• The proposed in vitro flow validation method, combined with PIV, offers a reliable alternative for validating CFD models of LA blood flow.
• Accurate CFD models are essential for understanding thrombosis in AF and guiding therapeutic strategies.
• The validated models and benchmark data will accelerate the development of more sophisticated LA CFD simulations.