In some settings, integration of operative ablation techniques with hemodynamic repair may be optimal. 9.2.2. Acute Treatment: Recommendations Recommendations for Acute Treatment of SVT in ACHD Patients COR LOE Recommendations I C-LD Acute antithrombotic therapy is recommended in ACHD patients who have AT or atrial flutter to align with recommended antithrombotic therapy for patients with AF.365 See Online Data 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.31,367 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 ACHD patients with nonfibrillatory atrial tachyarrhythmias appear to be at high risk, as well.367,459 Therefore, on the basis of available data, recommendations for antithrombotic therapy for ACHD patients who also have AT or atrial flutter are similar to those for patients with AF.10 I B-NR 2. Synchronized cardioversion is recommended for acute treatment in ACHD patients and SVT who are hemodynamically unstable.75,460 See Online Data Supplement 20. 