Background: Combination therapy with catheter ablation of the cavo-tricuspid isthmus and continued drug therapy, that is, "hybrid therapy," in patients with atrial fibrillation (AF) and drug-induced atrial flutter (AFL) is reported to be an alternative means of achieving and maintaining sinus rhythm. With respect to choosing this method among the rhythm control therapies, its long-term efficacy and the prevalence of AFL in patients with AF are very important and have not been fully elucidated.
Hypothesis: The purpose of this study was to investigate the long-term effectiveness of this hybrid therapy and the dose prevalence in Ic drug-induced AFL.
Methods: The subjects were 89 patients (aged 62.4 years, 72 men) with episodes of AF (paroxysmal type: 65, persistent type: 11, permanent type: 13). After 4 weeks of oral pilsicainide administration, the dose was increased in those with no documented AFL. The patients who experienced AFL with pilsicainide (Ic-AFL) underwent ablation.
Results: Pilsicainide administration resulted in the common type AFL in 17 patients (19.1%). The pilsicainide plasma concentration in the patients with Ic-AFL was significantly higher than in those without AFL (0.79 +/- 0.41 vs. 0.51 +/- 0.24 microg/ml, respectively, p < 0.01). During a 10-54 (mean 37 +/- 14) month follow-up period, sinus rhythm was maintained in 10 of 12 patients after successful ablation followed by continued antiarrhythmic drug administration.
Conclusions: Hybrid therapy with ablation and high doses of pilsicainide was useful in maintaining sinus rhythm in some selected patients with AF and drug-induced AFL.