RESUMO
BACKGROUND: Catheter ablation of typical atrial flutter (AFL) occurring in patients who take antiarrhythmic drugs for atrial fibrillation (AF) has been proposed as a curative approach for AF. The aim of this study was to evaluate the efficacy of this technique. METHODS: Forty-six consecutive patients (30 males, 16 females, mean age 67 +/- 9 years) with paroxysmal or persistent AF were submitted to right atrial isthmus ablation: 1) 33 patients (group 1) in whom typical AFL spontaneously occurred during oral treatment with propafenone (n = 19), flecainide (n = 9) or amiodarone (n = 6); 2) 13 patients (group 2) submitted to electrophysiological study while taking oral propafenone (n = 3), flecainide (n = 8) or amiodarone (n = 1), in whom sustained AFL was induced (n = 9) or AF was induced and AFL was obtained by intravenous administration of class IC drugs (n = 4). The same antiarrhythmic drug which induced the conversion of AF into AFL was administered after ablation. RESULTS: During a follow-up of 20 +/- 18 months (range 1-78 months), 23 patients (50%) remained asymptomatic and free from AF recurrences. Fifteen patients (33%) with AF recurrences reported a reduction in arrhythmia-related symptoms. Eight patients (17%) did not show symptomatic improvement. These results did not significantly differ between group 1 and group 2. The duration of follow-up was significantly longer in patients with AF recurrence. Among several clinical, echocardiographic and electrophysiological parameters, only atrial enlargement and the absence of structural heart disease were independently associated with AF recurrence. CONCLUSIONS: In selected patients with AF and drug-induced AFL, right atrial isthmus ablation and prosecution of the drug treatment is a safe and feasible approach, which totally eliminates or reduces symptomatic AF recurrences in one half and one third of patients, respectively. However, the number of AF-free patients tends to decrease over time.