This review is focused on electrical adaptational processes in patients with chronic AF. Cellular electrical remodeling includes shortening of action potential duration and effective refractory period that can be explained by concomitant alterations in ion channel activity. While most currents studied are reduced or unaffected, the inward rectifier I(K1) is increased in amplitude. The time courses of these changes and the putative molecular mechanisms suggest that electrical remodeling in chronically fibrillating human atria are adaptive processes. New therapeutic options could consist of supporting rather than reversing the adaptive mechanisms.