Opportunistic Screening for Atrial Fibrillation With Continuous ECG Monitoring in the Emergency Department

Summary

In a retrospective cohort of 65,244 consecutive adults receiving continuous ECG monitoring in one academic ED, 1,945 (3.0%) were discharged with at least 30 seconds of previously undocumented AF and no documented anticoagulation. Of these, 1,385 (71.2%) met the study's CHA2DS2-VASc criteria for anticoagulation. Undiagnosed AF was associated with 2.6 ischemic strokes per 100 person-years and an adjusted stroke HR of 3.00 (95% CI 2.39-3.76) versus patients without AF.

Why it matters

ED monitor data may contain clinically relevant AF that is never converted into a diagnosis or follow-up plan. Systems that capture and review sustained AF episodes before discharge could improve recognition, but this observational study does not show that automatic screening or anticoagulation from brief monitor episodes improves outcomes.

Main findings

• 1,945/65,244 (3.0%) were discharged with undiagnosed monitor-detected AF.
• 1,385/1,945 (71.2%) met the study's CHA2DS2-VASc anticoagulation criteria.
• Ischemic stroke incidence was 2.6 per 100 person-years in the undiagnosed-AF group.
• Adjusted stroke HR was 3.00 (95% CI 2.39-3.76) versus no AF and 1.32 (95% CI 1.02-1.71) versus known AF.

Limitations

Retrospective, single-center, selected population limited to patients placed on continuous monitoring; AF detection and downstream treatment were not randomized. A 30-second episode may not carry uniform treatment implications, and residual confounding affects the stroke association.