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Atrial Fibrillation

Woman with hands on chest

What is atrial fibrillation (AF)?

Atrial fibrillation (AF) is a common heart condition that causes an irregular and often rapid heart rate. Having AF increases a person’s risk of having a stroke or developing heart failure.

AF is a type of arrhythmia. Arrhythmias are disturbances in the way the heart beats and are commonly caused by changes to the electrical impulse within the heart. When your heart is healthy, a steady, electrical signal that originates in the Sino Atrial node in the right upper part of your heart keeps your heart at a regular beat, usually between 60 and 100 beats per minute. This is called sinus rhythm.

The electric signal in people with AF is random and chaotic which causes the two top chambers of your heart (the left and right atrium) to quiver and twitch. It becomes difficult for your heart to fill or empty itself of blood when it is quivering so much and out of sync with the two lower chambers (the ventricles), and blood may pool in the heart chambers and start clotting. Clots can dislodge from the heart and travel to vessels leading to the brain, kidneys, eyes, or peripherally in the arms or legs. The clot can block blood and oxygen flow to the brain or other organs.

There are three types of AF:

  • Paroxysmal AF: Episodes of AF come and go, sometimes in relation to exercise or stress. Episodes may last for minutes or hours but no longer than one week
  • Persistent AF: Episodes last for longer than one week
  • Long-standing persistent or permanent AF: AF episode has lasted longer than one year

What causes atrial fibrillation (AF)?

Experts aren’t exactly sure what causes atrial fibrillation (AF); however, they have identified several risk factors that make some people more likely to develop the condition. These include:

  • Older age (particularly over 65 years)
  • Congenital heart disease
  • Coronary artery disease
  • Diabetes
  • Excessive alcohol intake
  • Exercise: Healthy middle-aged males who have been engaged in strenuous endurance training for more than 10 years have the highest risk of developing AF caused by exercise
  • Genetics: AF can sometimes run in families
  • Heart attack
  • Heart disease or damage
  • High blood pressure
  • High thyroid hormone levels or other metabolic imbalance
  • Kidney disease
  • Lung infections (eg, pneumonia)
  • Medications such as adenosine, dobutamine, ondansetron, paclitaxel, and anthracyclines
  • Obesity
  • Sleep apnea
  • Stress.

What are the symptoms of atrial fibrillation (AF)?

Some people with atrial fibrillation (AF) have no symptoms and only get a diagnosis after a routine physical examination or an examination for an unrelated reason. Some people are not diagnosed until they have a stroke or mini-stroke.

Other people experience symptoms daily or only mild symptoms once in a while.

Symptoms may include:

  • Heart flutters or palpitations
  • Chest pain, discomfort, or tightness
  • Fatigue
  • Feeling dizzy, weak or faint
  • Having difficulty exercising
  • Nausea
  • Shortness of breath.

How is atrial fibrillation (AF) diagnosed?

See your doctor if you are experiencing symptoms of atrial fibrillation (AF).

Your doctor will ask about your family history of heart disease and check your heart rhythm, heart rate, and pulse. The diagnosis of atrial fibrillation is usually confirmed with an electrocardiogram (ECG), a test that records the heart's electrical activity.

Sometimes a portable ECG called a Holter monitor, may need to be worn at home for 24 hours, if a person's AF is not consistent. Monitors are also available that can be used for longer than 24 hours if needed.

How is atrial fibrillation treated?

Treatment varies depends on the type of atrial fibrillation (AF) but may include:

  • Anticoagulants (blood thinners)
  • Antiarrhythmics
  • Beta-blockers
  • Calcium channel blockers
  • Digoxin
  • Pacemakers
  • Radiofrequency ablation.