Atrial fibrillation (patient information)
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor-in-Chief: Prashant Sharma
Overview
Atrial fibrillation/flutter is a heart rhythm disorder (arrhythmia). It usually involves a rapid heart rate, in which the upper heart chambers (atria) contract in a very disorganized and abnormal manner. Instead of contracting regularly, the small chamber has chaotic electrical impulses that cause the heart to beat in an irregularly irregular fashion.
What are the symptoms of Atrial fibrillation?
You may not be aware that your heart is not beating in a normal pattern, especially if it has been occurring for some time.
Symptoms may include:
- Pulse that feels rapid, racing, pounding, fluttering, or too slow.
- Pulse that feels irregularly irregular.
- Sensation of feeling the heart beat. (palpitations)
- Shortness of breath while lying down. (orthopnea)
- Confusion.
- Dizziness, light-headedness.
- Fainting (syncope).
- Fatigue.
Note: Symptoms may begin or stop suddenly.
What causes Atrial fibrillation?
Arrhythmias are caused by a disruption of the normal electrical conduction system of the heart.
Normally, the four chambers of the heart (two atria and two ventricles) contract in a very specific, coordinated way. The electrial impulse that signals your heart to contract in a synchronized way begins in the sinoatrial node (SA node). This node is your heart's natural pacemaker.
The signal leaves the SA node and travels through the two upper chambers (atria). Then the signal passes through another node (the AV node), and finally, through the lower chambers (ventricles). This path enables the chambers to contract in a coordinated fashion.
In atrial fibrillation, the atria are stimulated to contract very quickly and differently from the normal pattern. The impulses are sent to the ventricles in an irregular pattern. This makes the ventricles beat abnormally, leading to an irregular (and usually fast) pulse. In atrial flutter, the ventricles may beat very fast, but in a regular pattern. If the atrial fibrillation/flutter is part of a condition called sick sinus syndrome, the sinus node may not work properly. The heart rate may alternate between slow and fast. As a result, there may not be enough blood to meet the needs of the body.
Atrial fibrillation can affect both men and women. It becomes more common with increasing age.
Causes of atrial fibrillation include:
- Alcohol use (especially binge drinking).
- Congestive heart failure.
- Coronary artery disease (especially after a heart attack or coronary artery bypass surgery).
- Heart surgery.
- High blood pressure (hypertension).
- Hypertrophic cardiomyopathy.
- Medications.
- Overactive thyroid gland (hyperthyroidism).
- Pericarditis.
- Valvular heart disease (especially mitral stenosis and mitral regurgitation).
When to seek urgent medical care?
Call your health care provider if you have symptoms of atrial fibrillation or flutter.
Diagnosis
The health care provider may may perform the following tests for this condition: An ECG shows atrial fibrillation or atrial flutter. Continuous ambulatory cardiac monitoring - Holter monitor (24 hour test) - may be necessary because the condition often occurs at some times but not others (sporadic).
Tests to find underlying heart diseases may include:
- Coronary angiography
- Echocardiogram
- Electrophysiologic study (EPS)
- Exercise treadmill ECG or Stress test
- Nuclear imaging tests
Treatment options
Treatment Strategies
Basic treatment strategies involve the following: In certain cases, atrial fibrillation may need emergency treatment to to get the heart back into normal rhythm. This treatment may involve electrical cardioversion or intravenous (IV) drugs such as dofetilide, amiodarone, or ibutilide. Drugs are typically needed to keep the pulse from being too fast.
Long-term treatment varies depending on the cause of the atrial fibrillation or flutter. Medications to slow the heartbeat may include:
- Beta-blockers
- Calcium channel blockers
- Digitalis
- Anti-arrhythmic drugs may be used to get the heart back into a normal rhythm. These medications may work well in many people, but they can have serious side effects. Many patients may go back to atrial fibrillation even while taking these medications.
Blood thinners, such as heparin and warfarin (coumadin) reduce the risk of a blood clot traveling in the body (such as a stroke). Because these drugs increase the chance of bleeding, not everyone will use them. Antiplatelet drugs such as aspirin or clopidogrel may also be prescribed. Your doctor will consider your age and other medical problems to decide which drug is best. In general, patients who have had a prior stroke should not use aspirin and clopidogrel together.
Some patients with atrial fibrillation, rapid heart rates, and intolerance to medication may need a catheter procedure on the atria called radiofrequency ablation.
For some patients with atrial flutter, radiofrequency ablation can cure the arrhythmia and is the treatment of choice. Some patients with atrial fibrillation and a rapid heart rate may need the radiofrequency ablation done directly on the AV junction (the area that normally filters the impulses coming from the atria before they move on to the ventricles).
Ablation, a procedure that disconnects or breaks the electrical pathway between the upper chambers (atria) and the lower chambers ventricles of the heart, in the AV junction can complicate into a complete heart block. This condition needs to be treated with a permanent pacemaker.
Where to find medical care for Atrial fibrillation?
Directions to Hospitals Treating Atrial fibrillation
What to expect (Outlook/Prognosis)?
The disorder is usually controllable with treatment. Many people with atrial fibrillation do very well.
Atrial fibrillation tends to become a chronic condition, however. It may come back even wtih treatment.
Possible complications
- Fainting (syncope), if atrial fibrillation and atrial flutter cause the pulse to be too quick or slow.
- Heart failure may occur.
- Stroke, if clots break off and travel to the brain (drugs that thin the blood such as heparin and warfarin can reduce the risk).
Sources
http://www.nlm.nih.gov/medlineplus/ency/article/000184.htm Template:WH Template:WS