Constructing Realistic Canine Bilayer Biatrial Mesh for the Modeling and Simulation of Atria Fibrillation

An improved appreciation of the mechanisms underlying atrial fibrillation (AF) is essential for better arrhythmia management. A deeper understanding requires a full consideration of atrial geometry. Here, we develop the first anatomically accurate high-resolution canine atrial computational bilayer model for AF studies. Canine CT-scan imaging data were segmented and used to reconstruct the Bachmann's bundle (BB), the left atrium (LA) and right atrium (RA). The LA is dilated to obtain the second layer. The RA endocardial layer consists of the sinus node (SAN), the pectinate muscles (PMs) and the crista terminalis (CT). The Ramirez-Nattel-Courtemanche canine cell model was used to simulate electrical activity. Activation time (AT) and action potential duration (APD) were computed. The obtained bilayer mesh has high resolution with average edge length 276±58μm. Action potential propagation from the SAN was realistic and its path along CS presumes an important role of the CS in the initiation and maintenance of rotors during AF. The propagation time from SAN to PVs was ~ 119 ms and APD90 was heterogeneous in the model. This new bilayer model with realistic geometry, combined with experimental data, will help to better understand AF and its underlying mechanisms, in order to develop better prognostic and therapeutic tools.