The LINEAR study is designed to compare the procedural efficacy, efficiency and safety of linear radiofrequency ablation of the cavotricuspid istmus using either a standar irrigated-tip ablation catheter or lattice-tip ablation catheter .The primary focus of the acute procedural data analysis will be: Procedural efficacy: This will be evaluated based on the rate of bidirectional CTI block persistence after 60 min waiting period documented by high resolution activation mapping. Furthermore, provocative test with intravenous adenosine infusion will be conducted to exclude dormant CTI conduction. Procedural efficiency: This will be evaluated based on the number of RF lesions delivered, time to achieve bidirectional CTI block, and fluoroscopy exposure time. Procedural safety: The incidence of procedural complications will be recorded.