Definition Atrial (ay-tree-all) fibrillation (fib-rill-ay-shun) is an abnormal rhythm in the heart that can lead to fast and uneven heart rates.
What is going on in the body? The top chambers of the heart are called the atria(ay-tree-ah). They feed blood into the larger chambers, called ventricles(ven-trick-uls). Rhythm refers to the speed of the heart rate and its regularity. In some people, the atria begin to fibrillate(fib-rill-ate) or twitch. This causes the normal, regular beating of the heart to change to a random, chaotic rhythm. This is called atrial fibrillation. The pulse becomes fast and irregular. Blood clots can form.
What are the signs and symptoms of the disease? Signs and symptoms of atrial fibrillation can include:
palpitations or a rapid, irregular heartbeat
falling blood pressure
shortness of breath
lightheadedness
occasionaly chest pain
What are the causes and risks of the disease? Most people with atrial fibrillation have a history of high blood pressure or a type of heart disease. If the thyroid gland is overactive, which is called hyperthyroidism (high-per-thigh-royd-ism), atrial fibrillation can occur. The risk for atrial fibrillation increases with age. Many elderly people have atrial fibrillation.
What can be done to prevent the disease? Certain drugs can be used to try to prevent atrial fibrillation. There is no sure way to prevent it.
How is the disease diagnosed? Atrial fibrillation is diagnosed by examining the person, checking the pulse, and listening to the heart with a stethoscope (steth-ah-scope). Since other types of heart rhythm problems called arrhythmias (ah-rith-me-ahs) can lead to an irregular pulse, the diagnosis is confirmed with a test called an electrocardiogram (ECG).
What are the long-term effects of the disease? Atrial fibrillation can lead to a weakening of the heart's ability to pump blood through the body, called congestive heart failure. Atrial fibrillation can also cause blockages in blood vessels or stroke.
What are the risks to others? Atrial fibrillation is not contagious and does not put other people at risk.
What are the treatments for the disease? The two main goals of treatment are to control the heart rate and to prevent blood clot problems. If atrial fibrillation is diagnosed within 48 hours, a doctor can give an electrical shock to the chest. This procedure can restore the normal heart rhythm.
If the normal heart rhythm cannot be restored, medications can be used. These medications include:
beta blockers, such as metoprolol or atenolol
calcium channel blockers, such as verapamil or diltiazem
digitalis
amiodarone
sotolol
flecainide
Anticoagulants (an-tea-coh-ag-you-lants), such as warfarin, commonly called "blood thinners", are used to prevent blood clots. Blood tests need to be done regularly to make sure a person is taking the right amount of the drug.
What are the side effects of the treatments? Side effects of some of the medications can be a slow heart rate or low blood pressure. People with asthma or breathing problems such as emphysema (em-fah-seem-ah) may not be able to take beta blockers. Anticoagulants can cause bleeding if not taken correctly or not monitored.
How is the disease monitored? Atrial fibrillation is monitored by regular examinations by a doctor. Repeat electrocardiograms may be done. Blood tests are taken to make sure that medications are properly dosed.
Author: Bill Harrison, MD Reviewer: HealthAnswers Australia Medical Review Panel Editor: Dr David Taylor, Chief Medical Officer HealthAnswers Australia Last Updated: 1/10/2001 Contributors Potential conflict of interest information for reviewers available on request
