Complex and fractionated electrograms ablation after circumferential pulmonary veins isolation has a controversial usefulness. If this is wide, it could eliminate a high proportion of them, so ablation of the rest might not be necessary. Our objectives are to determine the distribution of complex fractionated atrial electrograms in left atrium in persistent atrial fibrillation and to quantify how many of them are eliminated after a wide circumferential ablation of the left atrium.
We performed an electroanatomical map, with software for detecting complex fractionated electrograms, in 20 consecutive patients with persistent atrial fibrillation. Supported by the same map, but blind to electrical data, we performed a wide circumferential ablation (voltage drop to less than 0.05 mV or 90 % of baseline value) to isolate all the pulmonary veins guided by a circular catheter. We quantified complex and atrial electrograms eliminated with encircling lines. The distribution was homogeneous, but slightly more dense in the anterior, left lateral wall, in the septum and the roof (75 % , 63 % , 59 % and 56 % of all electrograms of each wall, respectively). The 35,7 % of them were eliminated after the circumferential ablation.
Complex fractionated electrograms are homogeneously dispersed in the left atrium, so a wide circumferential ablation is not enough to ablate them as it only eliminates a low proportion of them.