Radiofrequency catheter ablation of type 1 atrial flutter using large-tip 8- or 10-mm electrode catheters and a high-output radiofrequency energy generator: results of a multicenter safety and efficacy study.

OBJECTIVES

We studied the safety and efficacy of atrial flutter (AFL) ablation using 8- or 10-mm electrode catheters and a 100-W radiofrequency (RF) generator.

BACKGROUND

Large-tip electrode catheters may be more effective for ablation of AFL.

METHODS

There were 169 patients (age 61 +/- 12 years). Short-term end points were bidirectional isthmus block and no inducible AFL. After ablation, patients were seen at one, three, and six months, with event monitoring performed weekly and for any symptoms. Three quality-of-life (QOL) surveys were completed during follow-up.

RESULTS

Short-term success was achieved in 158 patients (93%), with 12 +/- 11 RF applications. The efficacy of 8- and 10-mm electrodes was similar (p = NS). The number of RF applications (10 +/- 8 vs. 14 +/- 8) and ablation time (0.5 +/- 0.4 h vs. 0.8 +/- 0.6 h) were less with the 10- versus 8-mm electrode, respectively (p < 0.01). Of 158 patients with short-term success, 42 patients were not evaluated for success at six months because of study exclusions. Of 116 patients with short-term success evaluated at six months, 112 (97%) patients had no AFL recurrence. Of those without AFL recurrence at six months, 95% and 93% remained free of symptoms at 12 and 24 months, respectively. Ablation of AFL improved QOL scores (p < 0.05) and reduced anti-arrhythmic and rate-control drug use (p < 0.05). Complications occurred in 6 (3.6%) of 169 patients, but there were no deaths.

CONCLUSIONS

Ablation of AFL with 8- or 10-mm electrode catheters and a high-power RF generator was safe and effective and improved QOL. The number and duration of RF applications were lower with 10- versus 8-mm electrode catheters.