Evidence map›Paper›PMID 40717865›Full record

ArticleHeart rhythm O22025

Diagnostic performance of single-lead electrocardiograms from a smartwatch and a smartring for cardiac arrhythmia detection.

Andre Briosa E Gala, Alexander James Sharp, David Schramm, Michael Timothy Brian Pope, Milena Leo, Richard Varini, Abhirup Banerjee, Kyaw Zaw Win, Manish Kalla, John Paisey and 2 more

Abstract read
In one paragraph

Article in Heart rhythm O2, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 3 papers.

0numbers the graph read from it
0cells of the map it votes in
3citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

3 citing papers in PubMed.

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4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

12 authors.

Andre Briosa E GalaDepartment of Cardiology, Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom.
Alexander James SharpDepartment of Cardiology, Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom.
David SchrammDepartment of Cardiology, Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom.
Michael Timothy Brian PopeWessex Cardiac Unit, University Hospital Southampton NHS Foundation Trust, Southampton, United Kingdom.
Milena LeoQueen Alexandra Hospital, Portsmouth, United Kingdom.
Richard VariniDepartment of Cardiology, Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom.
Abhirup BanerjeeInstitute of Biomedical Engineering, Department of Engineering Science, University of Oxford, Oxford, United Kingdom.
Kyaw Zaw WinQueen Elizabeth Hospital, Birmingham, United Kingdom.
Manish KallaQueen Elizabeth Hospital, Birmingham, United Kingdom.
John PaiseyWessex Cardiac Unit, University Hospital Southampton NHS Foundation Trust, Southampton, United Kingdom.
Nick CurzenFaculty of Medicine, University of Southampton, Southampton, United Kingdom.
Timothy Rider BettsDepartment of Cardiology, Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Background: Wearable devices are widely used for atrial fibrillation (AF) detection, yet most validation studies include only sinus rhythm or AF, likely overestimating diagnostic performance. Objective: This multicenter study assessed the performance of automated AF detection and physician interpretation of single-lead electrocardiograms (SL-ECGs) from the Apple Watch and CART Ring. Methodology: Participants underwent simultaneous 12-lead ECG and SL-ECGs from Apple Watch and CART Ring. Two cardiologists independently adjudicated all ECGs. Apple Watch and CART Ring classified recordings as "AF," "Not AF," or "Unclassified." Diagnostic performance for automated AF detection was evaluated in "worst-case" (all SL-ECGs) and lenient (excluding unclassified SL-ECGs) scenarios. Physician interpretation of SL-ECGs was also compared to 12-lead ECG. Results: Among 483 patients (median age, 66 years; 29% female), 196 (39%) had AF across 3 United Kingdom centers. A total of 2398 ECGs were analyzed. Interobserver variability was excellent (Cohen's kappa: Apple Watch, 0.85; CART Ring, 0.84). In the "worst-case" analysis, CART Ring outperformed Apple Watch (sensitivity, 84.6% vs 69.1%; specificity, 89.9% vs 72.6%). Apple Watch had more unclassified SL-ECGs (20.1%) than CART Ring (1.9%). The lenient analysis showed an improvement in sensitivity (CART Ring, 84.8 %; Apple Watch, 86.4%) and specificity (CART Ring, 91.2%; Apple Watch, 91.7%). Physician interpretation improved diagnostic performance for AF and sinus rhythm but remained limited for other arrhythmias. Conclusion: Apple Watch missed approximately 1 in 3 episodes of AF and a high number of unclassified SL-ECG. CART Ring demonstrated superior performance. Physician interpretation significantly improved AF diagnosis but remained unreliable for other arrhythmias, emphasizing the need for cautious integration of wearable ECGs into clinical practice.

Indexed as

Ambulatory monitoringApple watchAtrial fibrillationCART ringDigital healthElectrocardiogrammHealthWearable devices

Identifiers

PMID40717865
PMCPMC12287963

What OpenQuestion holds

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LicenceCC BY-NC-ND
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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.