What Is Atrial Fibrillation (AFib)?

Atrial fibrillation — commonly called AFib or AF — is the most prevalent heart rhythm disorder (arrhythmia) in adults worldwide. In a healthy heart, electrical signals trigger a coordinated, rhythmic squeeze of the heart's four chambers to pump blood efficiently. In AFib, the electrical signals in the heart's upper chambers (the atria) become chaotic and disorganized, causing them to quiver rather than contract effectively.

The result is an irregular, often rapid heart rate. While AFib itself isn't immediately life-threatening, it significantly increases the risk of stroke, heart failure, and other serious complications if left unmanaged.

Types of Atrial Fibrillation

  • Paroxysmal AFib: Episodes come and go, typically lasting minutes to hours and stopping on their own.
  • Persistent AFib: An episode lasting longer than 7 days that requires treatment to restore normal rhythm.
  • Long-standing Persistent AFib: Continuous AFib lasting more than 12 months.
  • Permanent AFib: The irregular rhythm is accepted as the ongoing state and rhythm-restoration is no longer pursued.

Common Symptoms of AFib

Some people with AFib experience no symptoms at all — it's discovered incidentally during a routine check-up or ECG. Others experience:

  • Heart palpitations — a fluttering, racing, or pounding sensation in the chest
  • Shortness of breath, especially during activity
  • Fatigue and general weakness
  • Dizziness or lightheadedness
  • Chest discomfort or pressure
  • Reduced ability to exercise

If you experience sudden chest pain, severe shortness of breath, or signs of stroke (facial drooping, arm weakness, speech difficulties), seek emergency care immediately.

What Causes AFib?

AFib has multiple contributing causes and risk factors. In some cases, there is no identifiable underlying cause (called "lone AFib"). Common contributors include:

  • High blood pressure (hypertension) — the most common risk factor
  • Coronary artery disease or previous heart attack
  • Heart valve disease
  • Heart failure or enlarged heart
  • Sleep apnea
  • Thyroid disorders (particularly overactive thyroid)
  • Excessive alcohol consumption ("holiday heart")
  • Obesity
  • Family history of AFib
  • Advancing age — risk increases significantly after age 60

How Is AFib Diagnosed?

Because AFib may be intermittent, it can be tricky to catch. Diagnostic tools include:

  • Electrocardiogram (ECG/EKG): The primary test; records electrical activity of the heart. Can confirm AFib when an episode is occurring.
  • Holter monitor: A portable ECG worn for 24–48 hours to catch intermittent episodes.
  • Event monitor or implantable loop recorder: For episodes that occur infrequently.
  • Echocardiogram: Ultrasound of the heart to assess structure and function.
  • Blood tests: To check thyroid function and rule out other causes.

Treatment Options for AFib

Treatment depends on the type of AFib, underlying causes, and the individual's overall health. The main goals are: controlling heart rate, restoring normal rhythm, and preventing stroke.

Rate and Rhythm Control Medications

Beta-blockers and calcium channel blockers slow the heart rate. Antiarrhythmic drugs work to restore and maintain normal rhythm. A cardiologist will determine the most appropriate medication based on your specific situation.

Blood Thinners (Anticoagulants)

Because AFib allows blood to pool in the atria (potentially forming clots), most AFib patients are prescribed anticoagulants to reduce stroke risk. Modern direct oral anticoagulants (DOACs) have largely replaced warfarin for many patients due to easier dosing and fewer dietary interactions.

Cardioversion

Electrical cardioversion delivers a controlled shock to "reset" the heart's rhythm. It's performed in a hospital setting and is often highly effective for restoring normal rhythm, though AFib can recur.

Catheter Ablation

A minimally invasive procedure where thin tubes (catheters) are guided to the heart to destroy the tissue causing the faulty electrical signals. Success rates vary, and some patients require more than one procedure.

Living Well With AFib

Many people with AFib live full, active lives with proper management. Lifestyle measures — reducing alcohol, managing blood pressure, treating sleep apnea, maintaining a healthy weight, and staying active — can reduce the frequency and severity of episodes. Regular follow-up with a cardiologist is essential.

This article is for educational purposes only. If you suspect you have AFib or have been recently diagnosed, work closely with a cardiologist to develop an individualized treatment plan.