Smartwatches and fitness trackers can flag an irregular rhythm that may be atrial fibrillation (AF).
What to do after an alert
- If you feel unwell, with chest pain, breathlessness, fainting or signs of a stroke (face drooping, arm weakness, speech problems), call 999.
- If you feel well, record an ECG on the watch if it can, and save it as a PDF with the date and time.
- Bear in mind that watches which only measure heart rate, without an ECG, tend to be less reliable.
- Note what you were doing and how you felt.
- Arrange an assessment. A doctor needs to confirm the rhythm on a medical ECG or monitor.
Why confirmation matters
Watches can give false alerts, for example with extra beats or a poor signal, and they can miss AF. If AF is confirmed, the most important next step is to assess your stroke risk and decide whether you need a blood thinner (anticoagulant).
How we can help
Send us your recordings when you book. At your consultation we'll review them, arrange a medical-grade monitor if needed, and explain the results and treatment options.
Medically reviewed by Dr Aftab Gill, Consultant Interventional Cardiologist (GMC 4499826). Last reviewed October 2026. This page gives general information and is not a substitute for personal medical advice.