Integrated Numerical Model for Hemodynamic Simulation of Human Atria Under Atrial Fibrillation by Coupling 3D Electrophysiological Activity

Atrial Fibrillation (AF) is the most common cardiac arrhythmia, increasing the chance of ischemic events five-fold. AF is characterized by fast and abnormal electrical activity, leading to disturbance in atrial contraction, resulting in pro-thrombotic zones due to blood stagnation. Literature shows that hemodynamic modeling using Computational Fluid Dynamics (CFD) has been used to evaluate the hemodynamic outcomes of atria chambers under AF; however, with simplifications related to the electromechanical effects of AF. This study aims to present an integrated analysis by coupling electrophysiological information to a hemodynamic model. A patient undergoing an electrophysiology study was enrolled. Firstly, the patient underwent Magnetic Resonance Imaging (MRI) scan, followed by an electrophysiology study. From MRI images, atrial shell was segmented through a semiautomatic image processing pipeline. Then, multi-electrode catheters were used to acquire electrophysiology signals, allowing determination of local activation times in the 3D atria shell. The 3D mapping provided AF activation patterns used as boundary conditions in the hemodynamic model. The mechanical effects from AF activity were coupled into the blood flow using a momentum method, allowing the local oscillatory wall motion to be mimicked due to the AF activity and its propagation effects through the blood flow. Statistical analysis of fundamental hemodynamic field properties (pressure and wall shear stress, WSS) exhibited a higher dispersion when considering the momentum method. The hemodynamic field presented larger pro-thrombotic zones (WSS \(\le \) 0.1 Pa) when considering the wall effects of AF activity