Comparative efficiency of externally-irrigated cooled-tip catheter vs. 8-mm-tip catheters in radiofrequency (RF) ablation of common atrial flutter

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 retrospective comparison between cooled-tip and and 8-mm-tip catheters in terms of efficacy and safety of RF ablation in atrial flutter.

Methods: Among 148 consecutive patients (pts) referred for common atrial flutter, cavotricuspid ablation was performed with an externally-irrigated cool tip catheter in 100 pts, and with an 8-mm-tip ablation catheter in 48 patients. RF current was applied for 60 seconds at powers of 50 W with the cooled-tip catheter, and in a temperature-controlled mode (65 degrees C/70 W) with the 8-mm-tip catheter, until bidirectional isthmus block was reached, or a total of 35 unsuccessful RF applications were performed.

Results: A higher initial failure rate with 8-mm-tip catheters was significant, compared to the externally-irrigated catheter (18% vs 4% ; p < 0.01). Significant differences were also found in some procedure parameters, such as the number of RF applications (26 +/- 8 vs 35 +/- 10; p < 0.04), fluoroscopy time (11 +/- 15 min vs 27 +/- 10 min; p < 0.01) and total procedure duration (95 +/- 23 min vs 145 +/- 35 min; p < 0.09). No major complications occurred. In a mean follow-up of 30 +/- 11 months atrial flutter recurred only in group treated with 8 mm catheter (10 patients among 48).

Conclusions: In achieving cavotricuspid isthmus block, RF ablation performed through cooled-tip catheters is more efficient than application through 8-mm-tip catheters.