Atrial Fibrillation



AFib happens when faulty electrical signals make the heart contract irregularly and much faster than usual. This may happen due to:

  • A problem with how the heart developed
  • Damage to the heart
  • Metabolic disorders—how the body processes food
  • Endocrine disorders—abnormal amounts of hormone in the body
  • Certain medicines or medical treatments

Sometimes the exact cause is not known.

Risk Factors

AFib is more common in males and people over 55 years of age. It may also be more likely in people with:

  • Family history of AFib
  • High blood pressure
  • Obesity
  • Injury or disease of the heart, such as:
    • Coronary artery disease
    • Heart failure
    • Heart attack
    • Endocarditis
    • Cardiomyopathy
    • Congenital heart disease or heart valve disease
  • Lung diseases, such as emphysema, asthma, blood clots in the lungs
  • Chronic endocrine disorders, such as overactive thyroid or diabetes

The use of certain prescription medicines, opioids, and general anesthesia can also raise the risk.

Some habits can raise the risk of AFib, such as:

  • Smoking
  • Excessive alcohol use
  • Excessive use of stimulants like caffeine
  • Physical and emotional stress



AFib may not cause any symptoms. Symptoms that do occur may range from mild to severe. Some people may feel:

  • An uneven or fast pulse or heartbeat
  • Racing feeling in the chest
  • A pounding feeling in the chest

AFib decreases the amount of blood pumped out to the body and may cause:

  • Lightheadedness, which can lead to fainting
  • Sweating
  • Pain or pressure in the chest
  • Shortness of breath
  • Tiredness or weakness
  • Problems exercising


The doctor will ask about symptoms and past health. A physical exam will be done. The doctor may suspect a problem based on symptoms.

An ECG test will be needed to diagnose AFib. Electrode stickers are placed on the chest, ankles, and wrist. It will show the electrical patterns of the heart. The test may be given at rest or during activity with one of the following:

  • Holter monitor —An ECG that is worn over a 24 to 48 hour period to help show problems that do not happen all the time
  • Stress testing—An ECG that is done to see changes during physical activity



For some people, AFib will go away on its own. Afib may also stop once the cause is managed.

AFib that continues will need regular treatment. The goals of treatment may include:

  • Stopping AFib (when possible).
  • Slowing the heart rate to manage symptoms.
  • Decreasing the risk of other problems such as blood clots and stroke.

The exact plan will depend on the cause of the AFib.

Heart Rhythm Control

AFib that is causing symptoms will need to be managed. The choice of treatment is based on specific cause and overall health. Options include:

  • Medicine to slow the heart rate or keep the heart in a regular rhythm.
  • Cardioversion a controlled electric shock that can reset rhythm of the heart.
  • Surgery that damages and scars small areas of heart muscle. The scars will help to redirect or block slow flow of electrical signals through the heart muscle. Options include:
    • Ablation—use of heat, cold, or electricity to damage or scars an area of the heart muscle. It will block extra signals.
    • Maze procedure and mini-maze procedure —create a pattern of scar tissue to control extra electrical signals

Clot and Stroke Prevention

AFib can increase the risk of clots and stroke. People with ongoing AFib may need medicine to lower the risk. A procedure called left atrial appendage closure (LAAC) can also decrease the risk of clots forming in the heart.

Reducing Triggers

Certain habits can trigger an episode of AFib or make it worse. To decrease the risk of making the AFib worse:

  • Stop smoking
  • Reduce or eliminate caffeine
  • Reduce stress
  • Eliminate or reduce alcohol intake


It is not always possible to prevent AFib. Taking steps to have a healthy heart may reduce the risk of some AFib.

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.

Edits to original content made by Denver Health.