Effects of Stepwise Ablation of Chronic Atrial Fibrillation on Atrial Electrical and Mechanical Properties Yoshihide Takahashi, Mark D. O’Neill, Mélĕze Hocini, Patricia Reant, Anders Jonsson, Pierre Jaïs, Prashanthan Sanders, Thomas Rostock, Martin Rotter, Frédéric Sacher, Stephane Laffite, Raymond Roudaut, Jacques Clémenty, Michel Haïssaguerre Electroanatomical mapping after stepwise catheter ablation of chronic atrial fibrillation showed the presence of scar, low-voltage atrial tissue, and prolongation of intra-atrial conduction. At 9 ± 5 months of follow-up, 98% of patients were in sinus rhythm, and the presence of left atrial contraction was shown in all patients. These results indicate that the electrical effects of widespread left atrial ablation are compensated for by recovery of left atrial contraction and are associated with an excellent clinical outcome.