Perform an electrocardiogram thanks to ECG watches

A hospital ECG uses ten electrodes to build twelve views of the heart's electrical activity, called leads. A watch produces one view, equivalent to lead I of a standard ECG. One lead is enough to see the rhythm: whether the beat is regular, and whether P waves are present. That is what atrial fibrillation detection relies on. It is not enough for the full cardiac assessment a 12-lead ECG allows, which is why a watch reading is a starting point for a conversation with a doctor, not a replacement for one.

It can tell you whether a 30-second recording looks like atrial fibrillation or like a normal sinus rhythm. It cannot detect a heart attack, and it does not look for other heart conditions. A normal result does not rule those out. If you feel unwell, or if you have chest pain or shortness of breath, contact emergency services rather than taking a reading.

No. The ECG app should not be used with a cardiac pacemaker, an implantable cardioverter-defibrillator, or any other implanted electronic device. The reason is not a safety risk from wearing the watch: an implanted device changes the shape of the ECG trace, so the reading cannot be interpreted reliably. If you have an implant and you have questions about your heart rhythm, your cardiologist and your device check-up are the right route.

Because the signal was not clean enough to classify with confidence, so the algorithm returned no answer rather than risk a wrong one. It usually comes down to contact and stillness: sit down, rest your arm on a table, keep your finger firmly on the metal ring, and stay still for the full thirty seconds. A loose fit or moisture on the wrist can all interrupt the signal.

The recording itself takes place on the watch and it appears in the Withings app either live during the recording if you choose to open your app, or as a final ECG and result in the app after your Bluetooth synchronization. So the short answer is no, you don't need your phone nearby, but you'll need it to open and read the final recording, even if a quick answer will be given on your watch screen.

Yes, you can export and share your ECG as a PDF directly in your Withings App, for free. You can't share an ECG directly through your watch though.

Taking and viewing an ECG does not require a Withings+ subscription. The Cardio Check-Up cardiologist review though is a separate, Withings+ subscription-only feature: you submit a recording you have already taken, a board-certified cardiologist reviews it, and you receive a report in under 24 hours. This feature needs a subscription, but the ECG feature and atrial fibrillation detection are included with your watch without any subscription.

Every recording is saved in the Withings app, where you can look back through them in the ECG results and share any of them with your doctor.

Thirty seconds. You keep a finger on the watch's face and wrap your hand around the metal ring, stay still, and the recording completes on its own. The result appears on the watch, then syncs to the Withings app where you can save it or share it.

The Withings ECG watches come with a variety of other features. You can track your sleep by wearing your watch at night and monitor your heart rate throughout the day and after sleep. Physical activity tracking is a standard feature on Withings connected watches, included in the entire ScanWatch range. Models with more advanced "medical" functionalities like the ScanWatch 2, Nova or Nova Brilliant also track temperature variations and blood oxygen levels. These features are crucial for monitoring high heart rates and potential heart failure symptoms and maintaining overall health. Wearable devices like these are designed to be used by people of all ages, including those who are 18 years old and above.