Simulated atrial fibrillation in a computer model of human atria

Atrial arrhythmias are the most frequent rhythm disorder in humans and often lead to severe complications such as heart failure and stroke. While different mapping techniques have provided significant information on the electro-physiological processes associated with atrial fibrillation (AF), the mechanisms underlying its initiation and maintenance remain unclear. To assist the study of the complex, spatio-temporal dynamics of AF, we developed a simplified homogeneous, isotropic, but realistic-size computer model of human atria that uses an ionic-based membrane model and whose geometry is derived from segmented MRI dataset. By representing the domain as a three-dimensional monolayer, the computational load is sufficiently reduced to enable the simulation of long duration arrhythmia. With this model, simulated atrial fibrillation (SAF), i.e. multiple reentrant wavelets, can be induced using a single-site burst pacing protocol. The model outputs both transmembrane potential maps and electrograms at any location in the atria, facilitating comparisons between simulation results and experimental or clinical data. It is shown here that our SAF model presents the same characteristics of spatio-temporal organization as real AF in terms of the correlation coefficient proposed by Botteron et al. (1995).