Less Common Causes

• Hyperthyroidism (overactive thyroid, uncommon).
• Pericarditis (inflammation of the outside lining of the heart, uncommon).
• Viral infection.

In at least 10% of people with AF, no underlying heart disease is found. In these people, AF may be related to alcohol or excessive caffeine use, stress, certain drugs, electrolyte or metabolic imbalances or severe infections. In some people, no identifiable cause can be found.

The risk of AF increases with age, particularly after age 60. According to the CDC, AF affects roughly 1 in every 10 persons aged 80 years or older.

Why Is Atrial Fibrillation Dangerous?

Many people live for years with atrial fibrillation without problems. However, because the atria are beating rapidly and irregularly, blood does not flow through them as quickly. This makes the blood more likely to clot. If the clot is pumped out of the heart, it can travel to the brain, resulting in a stroke. The likelihood of a stroke in people with AF is 5 to 7 times higher than in the general population. Although about half of all blood clots related to AF result in stroke, clots can travel to other parts of the body (kidney, heart, intestines), causing problems.

AF can also decrease the heart's pumping ability by as much as 20%-25%. AF combined with a fast heart rate over a long period of time can result in heart failure.

Chronic atrial fibrillation is associated with an increased risk of death.

How Is Atrial Fibrillation Diagnosed?

Four tests are used to diagnose atrial fibrillation, including:

• Electrocardiogram
• Holter monitor
• Portable event monitor (also called a loop recorder)
• Transtelephonic monitor

These monitoring devices help your doctor learn if you are having irregular heartbeats, what kind they are, how long they last, and what may be causing them.

How Is Atrial Fibrillation Treated?

Many options are available to treat AF, including medication, lifestyle changes, procedures and surgery. The choice of treatment for you is based on your rhythm and symptoms. The goals of AF treatment are to:

• Regain normal heart rhythm (sinus rhythm)
• Control the heart rate
• Prevent blood clots
• Reduce the risk of stroke