About Atrial Fibrillation

Atrial fibrillation (AF) occurs when your heart beat becomes irregular and rapid. Atrial fibrillation is the most common type of chronic cardiac rhythm disturbance, and becomes more likely as you get older. AF is experienced by 4.5 million people in Europe.1

Every person’s atrial fibrillation is different. Some people show no symptoms, often for years, while some people’s symptoms change from day to day. So treatment of both symptoms and AF is difficult. A continuous monitoring device from Medtronic may offer your doctor a fuller picture of your condition. Your doctor can treat your AF best if your pattern of AF is measured and understood.


Atrial fibrillation is a fast heartbeat (tachyarrhythmia) of the upper chambers of the heart, called atria. This stops your atria from working properly (become disorganized). The atria cannot pump all the blood out and some stays in the chambers where it may start to clot.


There are many possible causes of atrial fibrillation, including:

  • Cardiac valve defects
  • Congenital heart defects
  • Emphysema or other lung diseases
  • Exposure to stimulants, such as medications, caffeine or tobacco, or to alcohol
  • Heart failure
  • Heart attacks
  • Hypertension
  • Hyperthyroidism or other metabolic imbalance
  • Previous heart surgery
  • Sick sinus syndrome — this occurs when the heart's natural pacemaker stops functioning properly
  • Sleep apnoea
  • Stress due to pneumonia, surgery or other illnesses
  • Viral infections

Most commonly, atrial fibrillation occurs as a result of cardiovascular diseases. However, atrial fibrillation may also occur in people who do not have heart disease. In this case we call it lone atrial fibrillation.


Some people with atrial fibrillation have no symptoms and are unaware of their condition until their doctor discovers it during a physical examination. Those who do have symptoms may experience:

  • Palpitations, which are sensations of a racing, uncomfortable, irregular heartbeat or a flopping in your chest
  • Weakness
  • Light-headedness
  • Confusion
  • Shortness of breath
  • Chest pain.

Atrial fibrillation may be:

  • Sporadic: if a normal heartbeat returns on its own it's called paroxysmal atrial fibrillation. You may have symptoms that come and go, lasting for a few minutes to hours and then stopping on their own
  • Permanent: with permanent atrial fibrillation, symptoms may last until they are treated.

Risk Factors

While some types of atrial fibrillation are harmless, others may be serious. Anyone with cardiovascular diseases, including heart surgery, faces an increased risk of atrial fibrillation. The older you are, the greater your chances of developing atrial fibrillation. People with chronic medical problems and those with a family history of atrial fibrillation are also at higher risk. Binge drinking can also trigger an episode of atrial fibrillation.


It’s important that atrial fibrillation be diagnosed because it can increase the risk of a stroke. But, diagnosis may be difficult because atrial fibrillation is not predictable and symptoms are not always obvious. A correct diagnosis of atrial fibrillation starts with you. Your doctor or team of doctors will want to hear details about your symptoms. Besides this information, your doctor or team of doctors will need data about your heart’s electrical activity. If your doctor suspects a heart condition is causing atrial fibrillation, diagnostic tests may be needed to gather information about your heart.


  1. Fuster V, Rydén LE, Cannom DS, et al. ACC/AHA/ESC 2006 guidelines for the management of patients with atrial fibrillation—executive summary: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines and the European Society of Cardiology Committee for Practice Guidelines (Writing Committee to Revise the 2001 Guidelines for the Management of Patients With Atrial Fibrillation). Circulation. 2006; 114: 700-752.

Information on this site should not be used as a substitute for talking with your doctor. Always talk with your doctor about diagnosis and treatment information.

Last updated: 2 Dec 2010

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