Background: The use of irrigated-tip catheters enables elimination of almost all accessory pathways (APs) resistant to standard radiofrequency ablation (RFA). However, efficacy of irrigation catheter technology in the initial AP ablation has not been studied systematically yet.
Objectives: We tested whether the externally irrigated-tip catheters are more effective than the conventional-tip catheters for initial RFA of the posteroseptal and right free-wall APs, i.e., where application of the conventional RFA is expected to have a lower success rate.
Methods: Fifty consecutive patients (39 +/- 12 years, 32 males), who were subjected to primary catheter-ablation of the posteroseptal or right free-wall AP were randomly assigned to RFA with an externally irrigated-tip catheter (group I, n = 25; 45 degrees C/40 W outside the coronary sinus (CS) and 45 degrees C/30 W inside the CS) or a conventional-tip catheter (group C, n = 25; 60 degrees C/60 W outside and 55 degrees C/35 W inside the CS).
Results: No significant difference was identified between groups I and C with respect to acute success rate (88% vs. 96%), number of radiofrequency applications (6.8 +/- 4.7 vs. 6.1 +/- 4.3), RFA time (373 +/- 242 sec vs 365 +/- 241 sec), energy (11,022 +/- 7833 J vs. 12,870 +/- 11,414 J), fluoroscopy time (669 +/- 443 sec vs. 789 +/- 578 sec) and recurrence rate (18.2% vs. 16.7%). The only complication was encountered in group I, manifested as AV-block I-II degree after elimination of the right posteroseptal AP.
Conclusions: Irrigated-tip catheters are not more efficient than conventional catheters in initial RFA of the posteroseptal and right free-wall APs. Therefore, the use of irrigated-tip catheters is justifiable only for ablation of the APs resistant to previously attempted conventional RFA.