Category: Cardiology
Keywords: Atrial Fibrillation, Incidental Finding, ECG Monitoring, Anticoagulation (PubMed Search)
Posted: 4/19/2026 by Lena Carleton, MD
(Updated: 4/20/2026)
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Bottom line: Routine screening for atrial fibrillation (AF) is not recommended in the emergency department (ED). However, AF is often detected incidentally on continuous ECG monitoring. When identified, clinicians should inform the patient and consider anticoagulation if indicated.
Ischemic stroke remains a major cause of morbidity and mortality, with AF implicated in at least 12% of cases. Early detection allows for stroke prevention through timely anticoagulation.
In this single-center retrospective cohort study of 65,244 adult ED patients on continuous ECG monitoring (2020–2024), AF was detected in 10.1%. Of these, 48.7% had known AF, 21.6% were diagnosed or treated during the visit, and 29.6% were discharged without diagnosis or anticoagulation (“undiagnosed AF”), representing 3% of the total cohort. This group was more likely to be women, Black or Latino, Medicaid-insured, and without a primary care physician; 58.3% of the “undiagnosed AF” group met criteria for anticoagulation.
Over a median follow-up of 238 days, stroke incidence was 2.6 per 100 person-years in the undiagnosed AF group, compared with 2.4 in known AF and 0.5 in those without AF.
These findings suggest that opportunistic detection of AF in the ED may identify high-risk patients who could benefit from earlier diagnosis and anticoagulation.
Bottom line: Routine screening for atrial fibrillation (AF) is not recommended in the emergency department (ED). However, AF is often detected incidentally on continuous ECG monitoring. When identified, clinicians should inform the patient and consider anticoagulation if indicated. Though not explicitly discussed in this article, it is worth noting that incidental findings may also carry medicolegal implications.
Bismuth E, Jin BT, Molins E, et al. Opportunistic screening for atrial fibrillation with continuous ECG monitoring in the emergency department. Ann Emerg Med. 2026;87(1):56-65. doi:10.1016/j.annemergmed.2025.06.008
