Opportunistic Screening for Atrial Fibrillation With Continuous ECG Monitoring in the Emergency Department - 12/07/25

Doi : 10.1016/j.annemergmed.2025.06.008

Elsa Bismuth, BS ^a, Boyang Tom Jin, MS ^b, Emily Molins, BS ^b, Antra Nakhasi, BS ^b, Angelica Pritchard, BS ^b, Yi Wang, BS ^b, Christian Rose, MD ^b, Carl Preiksaitis, MD ^b, David Kim, MD, PhD ^b,^⁎
^a Department of Computer Science, Stanford University, Palo Alto, CA
^b Department of Emergency Medicine, Stanford University, Palo Alto, CA

^∗Corresponding Author.

Sous presse. Épreuves corrigées par l'auteur. Disponible en ligne depuis le Saturday 12 July 2025

Abstract

Study objectives

To determine the prevalence of undiagnosed atrial fibrillation detectable through continuous ECG monitoring in adult emergency department (ED) patients, and to estimate the stroke risk of ED patients discharged with undiagnosed atrial fibrillation.

Methods

Retrospective cohort study of 65,244 unique consecutive adult patients who received continuous ECG monitoring in an academic ED from August 23, 2020, to January 16, 2024. Primary outcome was the proportion of patients with at least 30 seconds of atrial fibrillation on continuous monitoring who were discharged without documented atrial fibrillation diagnosis or anticoagulation. Secondary outcomes included atrial fibrillation burden, proportion of cases suitable for anticoagulation based on CHA₂DS₂-VASc score, and incidence of ischemic stroke through August 31, 2024, by atrial fibrillation status on discharge (no atrial fibrillation, known atrial fibrillation, and undiagnosed atrial fibrillation). We compared demographic and insurance characteristics of patients with undiagnosed versus known atrial fibrillation. We estimated Cox proportional hazard models for ischemic stroke after ED visit, stratified by atrial fibrillation status and adjusting for CHA₂DS₂-VASc score.

Results

Of 65,244 monitored patients, 1,945 (3.0%) were discharged with undiagnosed atrial fibrillation, with 1,385 (71.2%) meeting criteria for anticoagulation. Compared to patients with known atrial fibrillation, patients with undiagnosed atrial fibrillation were younger (median age 72 [interquartile range, 50 to 84] versus 79 [interquartile range, 69 to 87] years), more likely to be women (49.6% versus 43.7%), on Medicaid (16.9% versus 7.0%), lack a primary care provider (22.5% versus 12.4%), and identify as Black (7.0% versus 3.7%) or Hispanic/Latino (17.1% versus 9.5%). Patients with undiagnosed atrial fibrillation had 2.6 ischemic strokes per 100 person-years of follow-up, with an adjusted hazard ratio for stroke of 3.00 (95% confidence interval, 2.39 to 3.76) compared to patients without atrial fibrillation on monitor, and 1.32 (95% confidence interval, 1.02 to 1.71) compared to patients with known atrial fibrillation.

Conclusion

Analysis of continuous ECG monitoring in the ED identified undiagnosed atrial fibrillation in 3% of patients, predominantly from underserved populations, and at high risk of stroke. Opportunistic screening in the ED could facilitate earlier diagnosis and anticoagulation to prevent stroke.

Le texte complet de cet article est disponible en PDF.

Keywords : Atrial fibrillation, Continuous monitoring, Opportunistic screening

Plan

Introduction

Background

Importance

Goals of This Investigation

Methods

Study Design and Population

Data Collection and Atrial Fibrillation Detection

Identification of Undiagnosed Atrial Fibrillation

Stroke Risk Assessment

Outcome Measures

Statistical Analysis

Validation of Continuous ECG Algorithm

Ethical Considerations

Results

Limitations

Discussion

	Please see page XX for the Editor’s Capsule Summary of this article.
	Supervising editor: Tyler W. Barrett, MD, MSCI. Specific detailed information about possible conflict of interest for individual editors is available at editors.
	Author contributions: DK conceived the study and supervised the research. DK, BTJ, EB, EM, AN, AP, and YW analyzed the data and reviewed patient records. EB, DK, and BTJ performed statistical analysis. EB, DK, CR, and CP drafted the manuscript, and all authors contributed substantially to its revision. DK takes responsibility for the manuscript as a whole.
	Data sharing statement: Deidentified patient data including continuous ECG waveforms, data dictionary, and no analytic code are available as of March 2025 at 1.0.0/ (for offline use) and mcmed-stanford-multi/ (for online use) to researchers who register for PhysioNet or Nightingale Open Science platform and sign the relevant data use agreement.
	All authors attest to meeting the four ICMJE.org authorship criteria: (1) Substantial contributions to the conception or design of the work; or the acquisition, analysis, or interpretation of data for the work; AND (2) Drafting the work or revising it critically for important intellectual content; AND (3) Final approval of the version to be published; AND (4) Agreement to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.
	Funding and support: By Annals’ policy, all authors are required to disclose any and all commercial, financial, and other relationships in any way related to the subject of this article as per ICMJE conflict of interest guidelines (see www.icmje.org/). The authors have declared that no competing interests exist.