Smartwatch alert uncovers PAC cardiomyopathy; LVEF 15% to 50%

AI system

System: Smartwatch arrhythmia detection (brand and model not stated)
Model: Not assessed
Release: Not assessed
Application developer: Not stated (the report does not name the device's maker)
Role: Not assessed
Configuration: Not assessed
Inputs and outputs: Not assessed
Autonomy: Not assessed
Workflow: An asymptomatic wearer whose smartwatch flagged arrhythmias and who took the flag to a physician. A primary care ECG followed by cardiology work-up including echocardiography, MRI and Holter monitoring. An electrophysiology service able to map and ablate a high-burden PAC focus.
Human oversight: Not assessed
Relation to AI: The watch's detection of “heart arrhythmias” is what sent an asymptomatic man to his doctor. Everything after (ECG, echo, MRI, mapping, ablation) was clinical. The report does not say what the watch flagged, whether a notification or an ECG reading, nor which algorithm. The device's contribution is therefore established only as the trigger.
AI contribution: The watch's detection of “heart arrhythmias” is what sent an asymptomatic man to his doctor. Everything after (ECG, echo, MRI, mapping, ablation) was clinical. The report does not say what the watch flagged, whether a notification or an ECG reading, nor which algorithm. The device's contribution is therefore established only as the trigger.

Studies: Not assessed
Study design: Not assessed
Measurement: Not assessed
Setting and sample: Not assessed
Measures: radiofrequency ablation restored LVEF to 50% at six months
Comparison: the same patient's LVEF before the radiofrequency ablation that the smartwatch alert led to (a treatment effect, not a with-versus-without-device comparison)
Results: Reference: 15%. Result: 50%.
Additional value from AI: Not assessed
Limitations: Not assessed
Denominators: Not assessed
Materials for replication: Not assessed

Participants: Developer: Not stated (the report does not name the device's maker).
Jurisdictions: Benefit: Göttingen, Germany.
Ownership and control: Not assessed
Dependencies: Not assessed
Cross-border connections: Not assessed
Geopolitical implications: Not assessed

Conditions for replication: The PAC burden is high enough to be caught by the watch and to cause the cardiomyopathy. The authors note case reports typically exceed 30%. The ventricular dysfunction is still reversible when the arrhythmia is eliminated.
Replication attempts: Not assessed
Later findings: Nothing after the six-month follow-up in the report was found.
Availability: Not assessed
Institutional decision: Not assessed
Grounds: Not assessed
Action and result: Not assessed
Success criterion: Not assessed

Assessed benefits: People.
Depth: People: 3.
Reasons: People: The alert started a chain that diagnosed a cardiomyopathy. The condition progressed to LVEF 15%. Ablation reversed it to LVEF 50% with resolution of symptoms. The authors present early detection as what allowed the heart failure to be treated before further progression.
Observed or intended: Not assessed
Rubric: Not assessed
Assessor and date: Not assessed
Alternative assessments: Not assessed
Fill: Independently studied

Kind: Not assessed
Related entries: Not assessed
Field: Healthcare (cardiology; heart failure). Consumer wearables.
Purpose: Smartwatch arrhythmia alerts are built to prompt medical review of irregular rhythms. The alert here served that purpose. The condition it uncovered, PAC-induced cardiomyopathy, is one the authors say wearables are not usually credited with finding.
Dates: Date basis unassessed: 2025 (precision unassessed). Updated: 21 October 2026.
Stage: Not assessed
Version: SHA-256: 7c943f9c0f73…

Case report Independent author

Soubh N, Rasenack E, Haarmann H, Zabel M, Bergau L (2025). Smartwatch-enabled early detection and treatment of cardiomyopathy induced by premature atrial contractions: a case report. European Heart Journal - Case Reports 9(4):ytaf151. doi:10.1093/ehjcr/ytaf151 (PMC12209856).