Low-voltage Areas Defragmentation in Sinus Rhythm for Radiofrequency Ablation of Persistent Atrial Fibrillation

Radiofrequency ablation has become standard practice in the approach strategy for the symptomatic treatment of atrial fibrillation. The interest of substrate ablation, completing the isolation of the pulmonary veins is controversial. The usual technique for the ablation of recurrent atrial fibrillation is primarily a disconnection of the pulmonary veins, which can be accomplished by isolating the veins one by one or two by two. The isolation of the pulmonary veins is followed most often by a defragmentation of the atrium (ablation of the substrate). The defragmentation is guided by a map of fragmented potentials, made through a topography catheter, to locate the most abnormal areas that are the target of ablation. This strategy requires extensive ablation of the left atrium, with a long procedure time and repeated many radiofrequency shots. On the one hand there is a risk of complication related to the duration of intervention, but also in the longer term of occurrence of flutter scar. In addition to pulmonary vein isolation, the goal is to identify patients with sinus rhythm atrial arrhythmogenic substrate. Once the sinus rhythm has been restored by electrical cardioversion or spontaneously, a voltage map is carried out to identify the most abnormal (low voltage) areas, and intra-atrial fragmented potentials are identified, either spontaneously or spontaneously by the extra-stimulus method. Ablation of these abnormal areas may lead to better long-term results, limiting prolonged radiofrequency shots and complications associated with longer procedure times.