Definition

Atrial fibrillation (AFib) is an erratic and often fast beating of the upper part of the heart. This part of the heart pushes blood into the lower section of the heart so it can pump blood out to the body. AFib can decrease the amount of blood that is pumped out to the body. AFib may be:

• Occasional (paroxysmal)—AFib starts and stops over short periods usually less than 48 hours
• Persistent—constant and lasts more than 7 days
• Longstanding persistent—continues for more than a year
• Permanent

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Causes

The beating of the heart is started and controlled by electrical signals. These signals start from an area of the heart called the SA node. The signals then move through the heart in an organized way. Problems with the SA node or other areas of the heart can disrupt how the heart contracts. Irregular signals may also start in other areas of the heart.

Afib may be caused by one or more of the following:

• Problem with how the heart developed or damage to the heart
• Metabolic disorders—how your body processes food
• Endocrine disorders—abnormal amounts of hormone in your body
• Certain medicine or other medical treatment

Sometimes the exact cause is not known.

Risk Factors

AFib is more common in men and people over 55 years old.

AFib may also be more likely in those 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
• Long term prescription medications such as opioids for pain relief
• Procedure that uses general anesthesia

Certain habits and food or drinks can increase the risk of AFib:

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

Symptoms

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

Fast beating in the upper part of the heart may cause:

• Irregular or rapid pulse or heart beat
• Racing feeling in the chest
• A pounding feeling in the chest

AFib that is decreasing the amount of blood pumped out to the body may cause:

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

Diagnosis

The doctor will ask about your symptoms and past health. A physical exam will be done. The doctor may suspect a problem after listening to the heart or hearing about symptoms. Tests to confirm may include:

• ECG —shows the electrical patterns of the heart.
• Holter monitor —ECG that is worn over a 24 to 48 hours period while you have a normal day. It can help show problems that do not occur all the time.
• Stress testing—ECG during exercise to see changes that only happen with physical activity.

Treatment

For some people, AFib will go away without treatment. For others, goals of treatment may include:

• Stopping AFib (when possible).
• Slowing the fibrillation down; especially if you are having symptoms.
• Decreasing the risk of other problems such as blood clots and stroke. Very important in AFib that keeps coming back or is permanent.

The exact plan will depend on the cause of your AFib. If a cause is found, that may need to be managed first. For example, stopping or changing medicine may stop the AFib.

Prevention

It is not always possible to prevent AFib. Talk to your doctor about your overall heart health. A healthy heart may reduce the risk of some AFib.