565 Evaluation of ablation patterns using a biophysical model of atrial fibrillation

Atrial fibrillation (AF) is the most common form of cardiac arrhythmia.Surgical/Radiofrequency (RF) ablation is a therapeutic procedure that consists of creating lines of conduction block to interrupt AF.The present study evaluated 13 different ablation patterns by means of a biophysical model of the human atria.In this model, ablation lines were abruptly applied transmurally during simulated sustained AF, and success rate, time to AF termination and average beat-to-beat interval were documented.The gold standard Cox's Maze III procedure was taken as reference.The effectiveness of twelve less invasive patterns was compared to it.In some of these incomplete lines (entailing a gap) were simulated.Finally, the computer simulations were compared to clinical data.The results show that the model reproduces observations made in vivo: (1) the Maze III is the most efficient ablation procedure; (2) less invasive patterns should include lines in both right and left atrium; (3) incomplete ablation lines between the pulmonary veins and the mitral valve annulus lead to uncommon flutter; (4) computer simulations of incomplete lines are consistent with clinical results of non-transumural RF ablation.Biophysical modeling may therefore be considered as a useful tool for understanding the mechanisms underlying AF therapies.