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7.4 Ongoing Management: Recommendations

I B-NR 6.  Acute antithrombotic therapy is recommended in patients with atrial flutter to align with recommended antithrombotic therapy for patients with AF.365

See Online Data Supplements 16 and 17. The risk of stroke associated with AF is well established, and several RCTs have demonstrated the efficacy of anticoagulation for stroke prevention in patients with additional risk factors.366 Anticoagulation has also been shown to prevent stroke when administered during the weeks immediately before and after cardioversion.367 Whether atrial flutter carries a risk of stroke similar to that in patients with AF has been debated in the past but is now supported by limited evidence from mechanistic, observational, and prospective studies that include patients primarily with atrial flutter.365–369 Several reports have suggested that the risk of stroke in patients with atrial flutter is mitigated by anticoagulation. Meta-analysis of 13 studies of patients undergoing cardioversion of atrial flutter reported short-term stroke risks ranging from 0% to 7%, and the thromboembolism rate in patients with sustained flutter in 4 studies averaged 3% annually.365 Other studies have reported similar risk and effectiveness of anticoagulation.369 Therefore, on the basis of the available data, recommendations for antithrombotic therapy for patients with atrial flutter are similar to those for patients with AF.10

IIa B-R 1.  Intravenous amiodarone can be useful for acute control of the ventricular rate (in the absence of pre-excitation) in patients with atrial flutter and systolic heart failure, when beta blockers are contraindicated or ineffective.350,370,371

See Online Data Supplements 16 and 17. Amiodarone may be useful for rate control in non–pre-excited atrial flutter because of its slowing of conduction through the AV node and prolongation of AV nodal refractoriness. Because it has less negative inotropic effect than beta blockers, diltiazem, and verapamil and may produce less hypotension, it may be preferred in critically ill patients or in those with tenuous hemodynamic stability. Because of potential toxicity, amiodarone should not be used for long-term rate control in most patients. Although unlikely, amiodarone may result in conversion of atrial flutter to sinus rhythm, so potential risks and benefits should be considered for patients with atrial flutter lasting ≥48 hours who are not adequately anticoagulated.10 However, amiodarone is typically used for rate control only when other options are greatly limited. For patients with atrial flutter, antithrombotic therapy is recommended according to the same risk profile used for AF.

Recommendations for Acute Treatment of Atrial Flutter (Continued) COR LOE Recommendations

Recommendations for Ongoing Management of Atrial Flutter COR LOE Recommendations

I B-R 1.  Catheter ablation of the CTI is useful in patients with atrial flutter that is either symptomatic or refractory to pharmacological rate control.243,372–375

See Online Data Supplements 16 and 17. Rate control can be difficult to achieve in atrial flutter, and a rhythm control strategy is often chosen. Catheter ablation of CTI-dependent atrial flutter is often preferred to long-term pharmacological therapy; in this rhythm, the CTI represents the optimal target for ablation because a line of ablation between the tricuspid valve annulus and inferior vena cava can effectively interrupt the circuit. A variety of techniques are applicable, including various catheter types, energy delivery systems, and mapping and visualization tools; generally, success depends on creation of a complete line of block and permanent interruption of conduction across the CTI (Table 8). Successful ablation is often heralded by intraprocedural interruption of the arrhythmia and subsequent EP demonstration of bidirectional block across the ablated tissue.

I C-LD 2.  Beta blockers, diltiazem, or verapamil are useful to control the ventricular rate in patients with hemodynamically tolerated atrial flutter.347–349

See Online Data Supplements 16 and 17. In some circumstances of persistent atrial flutter or in patients who have infrequent reasonably well-tolerated episodes of atrial flutter, a rate-control strategy may be chosen. In atrial flutter, the relatively slower atrial rate compared with AF often paradoxically results in more rapid AV nodal conduction because there is less concealed AV nodal conduction. Therefore, achieving adequate rate control can be difficult. Higher doses of beta blockers, diltiazem, or verapamil, and often a combination of agents, may be needed to achieve adequate rate control. Beta blockers are generally preferred in patients with heart failure. Avoidance of beta blockers, diltiazem, and verapamil in patients with pre-excited atrial flutter is recommended, given the potential for accelerated ventricular rates degenerating to ventricular fibrillation, as has been reported to occur rarely in similar patients with AF.274

I C-LD 3.  Catheter ablation is useful in patients with recurrent symptomatic non–CTI-dependent flutter after failure of at least 1 antiarrhythmic agent.134,327

See Online Data Supplements 16 and 17. No prospective RCTs have compared the efficacy or safety of antiarrhythmic drugs with that of catheter ablation for non–CTI-dependent atrial flutter. In general, catheter ablation of non–CTI-dependent atrial flutter is substantially more difficult than ablation of CTI-dependent flutter because the anatomic circuits are complex, are often not anatomically defined, and can be difficult to locate. Knowledge of the prior surgical or ablation approach and detailed activation and entrainment mapping of the tachycardia are useful during attempts at ablation (Table 8). The location of the circuit determines ablation approach and risks. Observational data support the relative effectiveness and safety of catheter ablation in experienced centers.134,327 Many of the atrial flutters that are observed during the first 3 months after catheter ablation or cardiac surgery will not persist beyond the periprocedural period, so attempts at ablation can be deferred unless pharmacological therapy and/or cardioversion are unsuccessful.327

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