Perspective:

Since the majority of AF triggers appear to arise in the pulmonary veins, PV isolation has become the cornerstone of AF ablation for paroxysmal AF. Unfortunately, the mechanisms implicated in persistent AF are much less well understood. Most contemporary data are consistent with a hierarchical model of AF with a high frequency rotor perpetuating the arrhythmia. The purported degree of rotor stability, however, varies across studies, perhaps due to technical and methodological differences. Whether the rotors are stable over prolonged time periods has significant implications on the possibility of targeting them with catheter ablation. The present study supports the existence of transient rotors in the majority of patients and majority of mapped regions, with a median of 3 rotations. The vast majority of rotors were centered on an area of short CL activity, but short CL activity was nonspecific for the identification of rotors. According to the present study, although short-term activation is unstable, patterns of atrial activation consistently repeat over a 10-minute period. The study does not answer the question of whether the rotors are active drivers of fibrillation or simply represent a passive phenomenon.