 Introduction Radiofrequency ablation RFA of typical atrial flutteru is the most successful method for treatment of atrial flutter. The acute peri-procedural efficacy is more than 95. 1 Typical atrial flutter circuit uses the area between inferior caval vein and tricuspid anulus, so a RFA of typical flutter is performed by providing a linear lesion from inferior caval vein to tricuspid valve this area is called as cavo-tricuspid isthmus. The recurrence of atrial flutter after ablation, which are caused by non-transmural RF lesion, are in less than 10 of cases. 2 During atrial flutter ablation, typically three electrophysiological catheters are used. Two catheters are diagnostic one 10-pole inserted into coronary sinus and the other 20-pole inserted in the right atrium with the distal tip laterally from the cavo-ticuspid isthmus. The third is ablation catheter, inserted in the CT isthmus. The location of all three catheters is monitored by fluoroscopy and by the EP signals on catheters. Also the ablation catheter during the ablation is monitored by fluoroscopy and by the signals on the catheter. 