Randomized study comparing radiofrequency ablation with cryoablation for the treatment of atrial flutter with emphasis on pain perception.

BACKGROUND Radiofrequency ablation (RF) of atrial flutter (AFL) has a high procedural efficacy, a low recurrence rate, and reports of procedure-related pain. The aim of the present study was to compare RF with cryoablation (cryo) for the treatment of AFL, with emphasis on pain perception during application of energy. METHODS AND RESULTS Fourteen patients (55+/-11 years, 11 males) with AFL were randomized to receive ablation of the cavotricuspid isthmus (CTI) by either RF or cryo. Cryothermia was delivered with the CryoCor Cryoablation System (10F, 6-mm tip), and radiofrequency energy was delivered with the use of an 8-mm-tip catheter. Pain was evaluated according to a visual analogue scale (VAS; 0 to 100). All patients in the cryo group were successfully ablated with a mean of 18 applications (9 sites), and RF was successful in 6 of 7 patients (not significant) with 13 applications (not significant). The mean temperature was -82 degrees C and 55 degrees C for cryo and RF, respectively. One patient in the cryo group perceived pain, versus all 7 patients in the RF group (P<0.05). The proportion of painful applications averaged 75.3% in the RF group and 2.0% in the cryo group (P<0.05), whereas the corresponding VAS for pain was 38.3+/-25.3 and 0.32+/-0.86, respectively (P<0.05). At 6-month follow-up, there were no recurrences of atrial flutter. CONCLUSION Cryo, as compared with RF, produces significantly less pain during application. Although in the present study there was no significant difference in efficacy, larger studies will be needed to definitively compare efficacy.