Device Detection of AF and Atrial Flutter (New) Recommendations for Device Detection of AF and Atrial Flutter Referenced studies that support new recommendations are summarized in Online Data Supplement 9. COR LOE Recommendations I B-NR In patients with cardiac implantable electronic devices (pacemakers or implanted cardioverter-defibrillators), the presence of recorded atrial high-rate episodes (AHREs) should prompt further evaluation to document clinically relevant AF to guide IIa B-R In patients with cryptogenic stroke (ie, stroke of unknown cause) in whom external ambulatory monitoring is inconclusive, implantation of a cardiac monitor (loop recorder) is reasonable to optimize detection of silent AF.S7.12-6 Recommendation-Specific Supportive Text (New) 1. Patients with AHREs detected by implanted devices are at increased risk of stroke and abun- dant data now link device-detected atrial tachy- cardia or AF (or AHREs) with the development of thromboembolic events.S7.12-1 S7.12-5 Remote monitoring with AHRE alerts increases the likeli- hood of detecting silent AF. However, it is unclear whether patients with AHREs benefit from oral anticoagulation. Careful review of stored electro- grams may confirm the presence of AF and rule out false positive events. Occasionally, the addi- tion of extended external electrocardiographic monitoring may be needed if data from the implanted device are uncertain. Prospective clini- cal trials of prophylactic anticoagulation based on device-detected AF are under way but have not been completed. Although increased duration of AHREs is associated with increased stroke risk, the threshold duration of AHREs that warrants anticoagulation is unclear. Current approaches factor in the duration of device-detected AF and the patient s stroke risk profile, bleeding risk, and preferences to determine whether to initiate long-term anticoagulation. 2. The cause of ischemic stroke remains unknown in 20% to 40% of patients, leading to a diag- nosis of cryptogenic stroke. 