What is atrial fibrillation?

Your heart normally beats in a steady, coordinated rhythm controlled by electrical signals. An arrhythmia occurs when these signals become disorganized.

Atrial fibrillation (AFib) is the most common type of arrhythmia. It happens when the upper chambers of the heart (the atria) beat rapidly and irregularly instead of contracting in a coordinated way.

AFib is one of the leading causes of stroke, heart failure, and cardiovascular complications worldwide. It can cause symptoms such as palpitations, shortness of breath, fatigue, or dizziness — but it can also be completely silent, which is why early identification matters.

How common is AFib?

AFib affects an estimated 10.5 million people in the United States and over 4% of the adult population in Europe. Its prevalence increases significantly with age.

• Under 50 years old: affects approximately 0.1–0.2% of the population.

• 60–70 years old: affects approximately 3.7–4.2% of the population.

• Over 80 years old: affects 10–17% of the population.

About 1 in 4 middle-aged adults in Europe and the United States may develop AFib in their lifetime.

How is AFib diagnosed?

The gold standard for diagnosing AFib is an electrocardiogram (ECG). Current medical guidelines recommend early screening, especially for people over 65.

Traditionally, diagnosing AFib required an ECG recorded in a doctor's office, limiting the window for identifying this condition. Wrist-based ECG devices like those made by Withings allow you to record a single-lead ECG at home and share the results with your doctor.

How is AFib identified on an ECG?

A healthcare professional looks at three key features on an ECG to identify AFib:

1. The P wave (the small wave before the main heartbeat signal) is absent or replaced by irregular fluctuations.

2. The QRS complexes (the main heartbeat signals) occur at irregular intervals, often with a rapid heart rate.

3. The baseline of the ECG tracing shows a tremor-like pattern caused by uncoordinated electrical activity in the atria.

Withings ECG devices use a machine learning algorithm that analyzes both the rhythm of the heartbeat and the shape of the electrical waves to classify the recording.

What are the main risk factors?

• Advanced age (risk increases significantly after 60)

• High blood pressure

• Obesity

• Diabetes

• Existing heart conditions or history of heart surgery

• Excessive alcohol consumption

What you can do

• Track regularly: Record ECGs periodically with your Withings device to build a history of your heart rhythm over time.

• Share with your doctor: Use the Withings PDF Health Report to share your ECG recordings with a healthcare professional for interpretation.

• Manage risk factors: Maintaining a healthy weight, staying physically active, limiting alcohol, and managing blood pressure can all help reduce AFib risk.

• Talk to your doctor: If your Withings ECG identifies signs of AFib, schedule an appointment with your doctor. Early management of AFib can help prevent complications such as stroke.

• In an emergency: If you experience severe chest pain, sudden difficulty breathing, or fainting, call emergency services immediately.

How is AFib managed?

If your doctor confirms AFib, treatment options may include:

• Blood-thinning medication to reduce the risk of blood clots and stroke.

• Medications to help control heart rate and rhythm.

• Catheter ablation, a minimally invasive procedure that targets the source of irregular signals.

Your doctor will determine the best approach based on your individual health profile.