Effect of Catheter Ablation on Left Atrial Function in Persistent Atrial Fibrillation

Cryoablation is performed using a single cryoballoon.In general, the cryoablation of each pulmonary vein is carried out twice. According to the objective condition, the operator determine whether or not to carry out an additional cryoablation. Then we will applicate electrophysiological substrate mapping for guiding ablation of atrial fibrillation,If mapping system detect a poor substrate,we should continue to ablate for left atrial roof and posterior line.

Each patient randomly allocated into the radiofrequency ablation group receives circumferential pulmonary vein isolation(CPVI),The default strategy is to create a circle surrounding the two ipsilateral pulmonary veins.We will mapping the left atrial subtrate. If mapping system detect a poor substrate,we should continue to ablate for left atrial roof and posterior line.