Radiofrequency catheter ablation of common atrial flutter--acute and follow-up results

Atrial flutter with a structurally well-defined macro-reentrant circuit in the right atrium has recently become amenable to radiofrequency ablation with the recognition of isthmus as a narrow zone of slow conduction. This study describes 20 consecutive and symptomatic patients with atrial flutter (15 males, 5 females; mean age 38.5 +/- 10.2 years) who underwent radiofrequency ablation in our institute in the last 18 months. Fourteen patients had structurally normal hearts, while the remaining six patients had specific disorders (prior surgery for closure of atrial septal defect-2, idiopathic restrictive cardiomyopathy-1, primary sinus node dysfunction-2, tachycardiomyopathy-1). The endpoints of a complete isthmus block and conversion to sinus rhythm were achieved in 19 of the 20 patients. Total number of pulses needed to attain the endpoints was a mean of 4.2 (range 1-5), each pulse being delivered for 90 seconds. At a mean follow up of 9.4 +/- 3.2 months (range 6-12 months), recurrence of atrial flutter was seen in one patient, atrial fibrillation in two and sinus node reentrant tachycardia in one. These results are comparable to those reported in the literature. Achievement of a complete isthmus block appears to be an important endpoint in obtaining optimal results. The issues of alternative sites of ablation, long-term results and advantages of an 8 mm tip catheter need to be examined further. In conclusion, radiofrequency ablation appears to be the preferred mode of treatment for patients with atrial flutter with excellent short-term and mid-term results.