Radiofrequency ablation of atrial flutter due to administration of class IC antiarrhythmic drugs for atrial fibrillation

In selected patients, atrial fibrillation (AF) converts to atrial flutter (AFl) due to treatment with class IC antiarrhythmic drugs. In this study, we prospectively investigated the effects of AFl ablation and continuation of drug therapy in patients with AF who developed AFl due to long-term administration of class IC antiarrhythmic drugs. The study population consisted of 187 patients from an AF registry with paroxysmal AF who were orally treated with flecainide (n = 96) or propafenone (n = 91). Twenty-four patients (12.8%) developed AFl during the course of treatment. In 20 of these patients (10.7%), electrophysiologic study revealed typical AFl. These patients underwent radiofrequency ablation of AFl. Ablation failed in 1 patient. All patients continued preexisting drug treatment. Recurrence of AF was assessed by ambulatory Holter monitoring and serial questionnaires. During a mean follow-up of 11 ± 4 months, the incidence of AF episodes was significantly lower in patients with a combined therapy (2.7 ± 3.6 per year) than in control subjects with a sole drug treatment (7.8 ± 9.2 per year, p <0.05) and than before therapy (10.2 ± 5.4 per year, p <0.001). Subgroup analysis revealed that 7 patients (36.8%) remained symptom free with no evidence of atrial tachyarrhythmia. Eight additional patients (42.1%) had ongoing paroxysmal AF, however, with a significantly lower incidence of AF episodes than before therapy (2.3 ± 1.6 per year vs 11.5 ± 5.0 per year, p <0.001). In the remaining 4 patients (14.7%), no beneficial effect of AFl ablation was found. It is concluded that in patients with AF who develop typical AFl due to administration of class IC antiarrhythmic agents, a combined therapy with catheter ablation of AFl and continuation of drug treatment is highly effective in reducing occurrence and duration of atrial tachyarrhythmias.