"Smartwatch Detection of Cardiac Arrhythmias: A Systematic Review of Accuracy, Clinical Utility, and Limitations"

Cardiac-enabled smartwatches have emerged as a novel class of wearable devices capable of detecting atrial fibrillation (AF) and other arrhythmias in real-world settings. Leveraging photoplethysmography (PPG) and single-lead electrocardiography (ECG) sensors, these devices offer ambulatory rhythm assessment that may facilitate earlier diagnosis, especially in asymptomatic individuals. This systematic review critically evaluates the diagnostic performance, clinical utility, and operational limitations of smartwatch-based arrhythmia detection. A comprehensive literature search was conducted across PubMed, Scopus, Embase, and IEEE Xplore for studies published between 2010 and 2025 that compared smartwatch readings with clinical standards. Twenty-two studies were included, encompassing over 450,000 participants across diverse settings. Most devices showed high sensitivity and specificity for AF detection, with Apple Watch outperforming other models in large-scale trials. However, detection of non-AF arrhythmias such as supraventricular tachycardias and premature ventricular complexes was less reliable. Performance varied by device type, user engagement, skin tone, and study design. Special populations—including pregnant women and elderly individuals—remained underrepresented, revealing key gaps in device validation. Integration into clinical workflows was limited by interoperability issues, data accuracy, and interpretation burden. Despite these challenges, smartwatches represent a promising avenue for population-level screening, particularly in resource-limited settings aligned with digital health goals like Saudi Arabia’s Vision 2030. To fully realise their potential, strategic investment is needed in cross-population validation, clinician training, and regulatory guidance. This review concludes that while smartwatch-based rhythm monitoring is promising, its adoption must be guided by rigorous evidence, equitable access, and meaningful integration into clinical practice.