 Randomization: 1 to 1 for ICE vs. non ICE RF ablation will be done routinely, as it is done in the center. In the Ice group, ICE probe will be inserted through the left femoral vein in the right atrium TH ICE will be used for the visualization of the anatomy of CTI area and the visualization of the catheter during RF delivery. In case of the non-ICE group, RFA will be done without ICE catheter, as it is done routinely now. In both groups, the diagnostic catheters 10-pole CS and 20-po in the RA and ablation catheter will be the same. In the non-ICE group, the location of the catheters will be assessed by fluoroscopy and by signals on catheters. At the end of ablation, total fluoroscopy time, the number and length of ablation and the duration of procedure will be calculated. On the day and two weeks after the procedure, the bleeding complication will be assessed. 