Objective:To evaluate the safety and efficacy of cooled radiofrequency(RF)ablation for arrhythmias by saline irrigation catheter.Methods:Twenty-six patients with arrhythmia underwent cooled RF ablation by saline irrigation catheter after failure of conventional catheter RF ablation.5cases were with a right-and 1 case with a left-sided resistant accessory pathway

5 cases were with atrial tachycardia

5cases with typeⅠatrial flutter

6 cases with paroxysmal atrial fibrillation

and 4 cases with idiopathic ventricular tachycardia.The ablation parameters were compared between saline irrigation catheter RF ablation and conventional catheter RF ablation.The safety and efficacy of cooled RF ablation by saline irrigation were recored and the average duration of follow-up was 15.8±7.5 months.Results:①There were higher peak electrode temperature

impedance

and lower RF power with conventional catheter electrode than with saline irrigation electrode

and there was no difference in the ablation duration.②Acute successful rate of cooled RF ablation by saline irrigation was 100%(26/26)

and long-time successful rate was 88.5%(23/26).③A stroke occurred in 1case

and eschar formed on the catheter electrode in 6 cases with conventional catheter electrode.No complications occurred with saline irrigation electrode.Conclusions:Cooled RF ablation by saline irrigation catheter had good efficacy and high safety in treating arrhythmias

especially for those located deep.