Prospective Randomized Comparison of Closed Cooled‐Tip versus 8‐mm‐Tip Catheters for Radiofrequency Ablation of Typical Atrial Flutter

Cooled‐Tip vs 8‐mm‐Tip Ablation of Atrial Flutter.Introduction : Cooled‐tip and 8‐mm‐tip catheters have been found to be more effective than conventional 4‐mm‐tip catheters for radiofrequency (RF) ablation of common atrial flutter. The aim of this study was to compare the efficacy and safety of cooled‐tip and 8‐mm‐tip catheters for flutter ablation in a randomized, prospective study. Methods and Results : In 100 consecutive patients referred for ablation of common atrial flutter, cavotricuspid ablation was performed with a closed cooled‐tip catheter ( n = 50 ) or an 8‐mm‐tip ablation catheter ( n = 50 ). RF current was applied for 60 to 120 seconds at powers of 40 to 50 W with the closed cooled‐tip catheter and in a temperature‐controlled mode (65°C/70 W) with the 8‐mm‐tip catheter. The endpoint was achievement of a bidirectional isthmus conduction block. Cross‐over was performed after 15 unsuccessful RF applications for each of the catheters. Complete bidirectional isthmus block was achieved in 99% of patients. Cross‐over was performed in 11 patients after primary use of the cooled‐tip catheter and in 9 patients after primary ablation with the 8‐mm‐tip catheter. No significant differences were found in the procedure parameters, such as overall RF applications ( 12.4 ± 11.3 vs 12.9 ± 8.6 ), ablation duration ( 42 ± 43 min vs 39 ± 27 min ), and fluoroscopy time ( 17.0 ± 18.7 min vs 15.7 ± 10.7 min ). In a mean follow‐up of 8.3 months, 1 patient in the cooled‐tip group and 3 patients in the 8‐mm‐tip group had recurrence of common atrial flutter. Conclusion : Use of the closed cooled‐tip ablation catheter and the 8‐mm‐tip catheter have equal and high efficacy for RF ablation of common atrial flutter.