Atrial Fibrillation and Heart Disease
What Causes Atrial Fibrillation?
Atrial fibrillation is associated with many conditions, including:
- High blood pressure
- Coronary artery disease (blockages in the heart's arteries)
- Heart valve disease
- Previous heart surgery
- Chronic lung disease
- Cardiomyopathy (disease of heart muscle that causes heart failure)
- Congenital heart disease (heart disease present at birth)
- Pulmonary embolism (blood clot in lungs)
Less Common Causes of Atrial Fibrillation
Less common causes of atrial fibrillation include:
Hyperthyroidism (overactive thyroid)
- Pericarditis (inflammation of the outside lining of the heart)
- Viral infection
In at least 10% of people with AF, no underlying heart disease is found. In many of 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 cause can be found.
The risk of AF increases with age, particularly after age 60. According to the CDC, AF affects roughly one in every 10 people ages 80 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 a blood 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 five to seven 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 -- such as the kidney, heart, or intestines -- also 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 period of days to months can result in heart failure. Control of AF can then improve heart failure.
How Is Atrial Fibrillation Diagnosed?
Four tests are used to diagnose atrial fibrillation, including:
- 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.