AFib

Medical Abbreviation
AFib

AFib stands for Atrial Fibrillation.

What does AFib mean?

an irregular, often rapid heart rhythm from the atria

AFib stands for atrial fibrillation, the most common sustained heart rhythm disturbance. Instead of contracting in a coordinated way, the upper chambers of the heart (the atria) quiver rapidly and irregularly, which makes the pulse irregular and often fast. It can cause palpitations, breathlessness, and fatigue, though some people have no symptoms. A major concern is stroke risk, because blood can pool and form clots in the fibrillating atria, so many patients are treated with anticoagulants. AFib is also written AF.

When is AFib used?

AFib is documented across cardiology, emergency, and general medical notes, and is diagnosed on an ECG.

Frequently asked questions

What does AFib stand for?

AFib stands for atrial fibrillation, an irregular and often rapid heart rhythm from the atria. It is also written AF.

Why is AFib dangerous?

Blood can pool and clot in the fibrillating atria, raising the risk of stroke, which is why anticoagulants are often used.

What are common symptoms of AFib?

Palpitations, breathlessness, and fatigue, although some people have no symptoms at all.

How is AFib diagnosed?

It is diagnosed on an electrocardiogram, which shows the irregular rhythm without clear P waves.

Related abbreviations

ECG · NSR · INR

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Study reference only — not medical advice. Always consult qualified sources and supervisors for clinical decisions.