What does this notification mean?

Your watch has detected an irregular pattern in your heart rhythm. This means the timing between heartbeats was not consistent during a recent check. An irregular rhythm can have many causes — some are harmless, while others may benefit from medical attention.

How is this detected?

Your watch uses a PPG (photoplethysmography) sensor on the back of the case. This sensor emits green light and measures how it reflects off blood flowing through the vessels in your wrist. Changes in blood flow create a pulse signal that reveals your heart rhythm pattern.

Every 10 minutes, an algorithm analyzes your pulse signal in the background. If an irregular rhythm is detected, you receive a notification on your watch and in the Withings App.

What should you do?

• Record an ECG — Your watch can record a single-lead electrocardiogram for more detailed insight into your heart rhythm. An ECG measures the electrical activity of your heart directly.
• Talk to your doctor — Share your notification and any ECG recordings with your healthcare professional. You can export a PDF from the Withings App to bring to your appointment.
• Keep tracking — Continue wearing your watch as usual. Tracking over time helps you and your doctor understand whether irregular rhythms are occasional or recurring.

When to seek urgent care

If you experience chest pain, pressure, tightness, sudden shortness of breath, fainting, or what you think may be a heart attack, call emergency services immediately. Do not wait for a notification from your watch — this feature cannot detect heart attacks.

Important limitations

• Not a diagnosis — This notification is not a medical diagnosis. It is intended as informational data to share with your doctor.
• Not continuous monitoring — Your watch checks periodically, not constantly. It may not detect all instances of irregular heart rhythm.
• Cannot detect heart attacks — This feature monitors rhythm patterns only. It is not designed to detect heart attacks or other acute cardiac events.
• Pacemaker or implanted device — Do not use this feature if you have a cardiac pacemaker, implantable defibrillator, or other implanted electronic device.