Evaluation of Modelling Methods for Electrocardiographic Fibrillatory Waves in Atrial Fibrillation

The forward problem in electrocardiography maps epicardial activity to body surface potentials (BSPM), but the most detailed bidomain model with a finite element numerical solution is computationally expensive. We simulated sinus rhythm and atrial fibrillation activity in patient-specific 3D atria models (both volumetric and bilayer) and compared simplified infinite volume conductor method for forward BSMP calculation, against a ground truth pseudo-bidomain with finite element solution. Simplified models reproduced ECG morphology with high fidelity, while amplitudes were systematically underestimated due to absence of torso inhomogeneities. BSPM dynamics, including vector length and orientation, were well preserved, though gradients were exaggerated.