Observational data, however, support the relative effectiveness and safety of catheter ablation in experienced centers.135,327 Many of the atrial flutters that are observed during the first 3 months after ablation or cardiac surgery will not persist beyond the periprocedural period, so attempts at ablation can be deferred unless attempts at pharmacological therapy or cardioversion are IIb B-R Flecainide or propafenone may be considered to maintain sinus rhythm in patients without structural heart disease or ischemic heart disease who have symptomatic recurrent atrial flutter.383 385 See Online Data and 17. Data to support the recommendation for flecainide and propafenone for maintenance of sinus rhythm in patients with atrial flutter is derived from trials that pooled patients with AF and atrial flutter, with the vast majority of the patients having AF. It is therefore possible that these agents are not as effective for treating isolated atrial flutter as they are for AF.386 Flecainide and propafenone may result in slowing of the atrial flutter cycle length, which may lead to a rapid 1:1 ventricular response.387 Because of this, caution is advised with flecainide and propafenone in patients with atrial flutter at risk of 1:1 conduction. The risk may be reduced by coadministration of medications that slow AV nodal conduction, such as beta blockers, verapamil, or diltiazem. IIb C-LD 2. Catheter ablation may be reasonable for asymptomatic patients with recurrent atrial flutter.102,121,372 See Online Data and 17. Catheter ablation of atrial flutter is highly effective, with single-procedure success rates >90%102 and an excellent safety profile.102,121 In patients with recurrent atrial flutter, long-term maintenance of sinus rhythm is more likely with ablation than with pharmacological therapy.372 Also, ablation may avoid potential development of tachycardia-mediated cardiomyopathy. Recommendations for Ongoing Management of Atrial Flutter (Continued) COR LOE Recommendations 8. 