[Catheter ablation of atrial fibrillation: techniques and results].

Over the last years, major advances have been made in catheter ablation of atrial fibrillation (AF). Early attempts to reproduce the catheter maze procedure, although barely effective, led to the observation that ectopic foci often originating in the pulmonary veins triggered paroxysmal atrial fibrillation. This, in turn, has heralded the development of focal ablation and, later on, pulmonary vein isolation techniques. Limitations found in patients with persistent and permanent atrial fibrillation led to the development of more effective techniques to modify the substrate for AF maintenance. Thus, the strategy of reproducing catheter maze surgery was resumed, and now this procedure is performed using a computerized mapping system that provides three-dimensional reconstruction of atrial chambers and ablation with radiofrequency (RF) equipment capable of producing deeper and transmural lesions. Larger lesions at the pulmonary vein antra cause changes in the substrate for AF maintenance, as well as autonomic denervation of the left atrium, and seem to result in better control of atrial fibrillation. These findings have been stimulating the development of new techniques to identify more specific areas associated to the initiation and maintenance of atrial fibrillation. The use of different methods by different investigators has been confusing for physicians who are not familiar with the new techniques to treat atrial fibrillation. The purpose of this update, therefore, is to review the key techniques used today, as well as the expected results and involved risks.