Fitness Trackers and Other Wearable Devices in Cardiology for Prevention, Screening and Diagnosis of Arrhythmias: Focus on Atrial Fibrillation

Background: Atrial fibrillation (AF) is the most common sustained arrhythmia worldwide and a major cause of ischaemic stroke, heart failure, and cardiovascular mortality. Due to its frequently asymptomatic and paroxysmal nature, many cases remain undiagnosed until serious complications occur. This diagnostic challenge is particularly relevant in physically active individuals, as arrhythmias may be triggered or exacerbated during sports and exercise. Traditional monitoring methods have important limitations in sensitivity, duration, and long-term patient acceptability. Aim: This narrative review evaluates the current evidence on fitness trackers and other wearable devices in the prevention, screening, and diagnosis of atrial fibrillation, focusing on clinical performance, patient-centred aspects, limitations, and applications in sports and exercise. Material and Methods A comprehensive narrative review was performed, incorporating the 2024 ESC Guidelines, major clinical trials, meta-analyses, and recent studies on photoplethysmography (PPG) and single-lead ECG technologies across various wearable form factors. Results: Wearable devices, including smartwatches, adhesive patches, and smart textiles, achieve high diagnostic accuracy for AF detection (sensitivity and specificity frequently 90–97%). They improve identification of subclinical and silent AF in high-risk and physically active populations and provide markedly better comfort and adherence during sports and exercise. Key challenges include motion artefacts, false-positive alerts, and the scarcity of large randomised trials with hard clinical outcomes. Conclusions: Wearable technologies have the potential to transform AF care from reactive treatment of complications to proactive, personalised prevention. While already clinically valuable, widespread adoption requires overcoming technical barriers and confirming long-term benefit in robust outcome trials.