Atrial fibrillation (AF) is the most common human arrhythmia and leads to increased morbidity and mortality. Because of demographic changes, the prevalence of AF will increase in the next decades, requiring better primary prevention strategies and better treatment options.  In 1998, Haissaguerre et al. described triggering foci in the pulmonary veins (PV) as the prevailing pathophysiological initiator of paroxysmal AF. Since then, multiple studies have been conducted using the technique of pulmonary vein isolation (PVI) to eliminate AF. In short term follow-up, success rates of 60-75% in patients with paroxysmal AF are reached, with significantly worse results in persistent AF of approximately 50%. Due to arrhythmia recurrence, multiple procedures are necessary, especially in patients with persistent AF, to achieve these results. It is supposed that the cause of arrhythmia recurrence is relapse of pulmonary vein connection in patients with paroxysmal AF, and the insufficient substrate modification or new substrate development in patients with persistent AF. Future techniques like contact force control could improve lesion formation leading to improved PVI and substrate modification.