Over the last decade, catheter ablation of atrial fibrillation (AF) has evolved from an attempt to replicate the surgical maze procedure to a more easily achieved goal of pulmonary vein isolation. Once the importance of the pulmonary veins in the initiation of AF episodes was discovered, catheter ablation approaches evolved from focal ablation within the pulmonary veins, through segmental ostial ablation (paroxysmal AF), to the current approach of left atrial extraostial encirclements of the pulmonary veins (paroxysmal or persistent AF). This approach not only isolates the source of premature beats and triggers of AF, but is also thought to affect the substrate of AF maintenance. Current efforts are directed at the development of coil- and balloon-based catheter ablation systems using alternative energy sources. It is hoped that these new technologies will provide an alternative to antiarrhythmic drug therapy as first line of therapy for recurrent AF...