Atrial fibrillation or flutter
Atrial fibrillation or flutter is a common type of abnormal heartbeat. The heart rhythm is fast and irregular in this condition.
Auricular fibrillation; A-fib
When working well, the four chambers of the heart contract (squeeze) in an organized way.
The electrical signal that tells your heart to contract begins in an area called the sinoatrial node (also called the sinus node or SA node). These signals help your heart pump the right amount of blood for your body's needs.
In atrial fibrillation, the electrical impulse of the heart is not regular.
- Parts of the heart cannot contract in an organized pattern.
- As a result, the heart cannot pump enough blood to meet the body's needs.
In atrial flutter, the ventricles (lower heart chambers) may beat very rapidly, but in a regular pattern.
These problems can affect both men and women. They become more common with increasing age.
Common causes of atrial fibrillation include:
- Alcohol use (especially binge drinking)
- Coronary artery disease
- Heart attack or heart bypass surgery
- Heart failure or an enlarged heart
- Heart valve disease (most often the mitral valve)
- Overactive thyroid gland (hyperthyroidism)
- Sick sinus syndrome
You may not be aware that your heart is not beating in a normal pattern.
Symptoms may start or stop suddenly. This is because atrial fibrillation may stop or start on its own.
Symptoms may include:
- Pulse that feels rapid, racing, pounding, fluttering, irregular, or too slow
- Sensation of feeling the heart beat (palpitations)
- Dizziness, light-headedness
- Loss of ability to exercise
- Shortness of breath
Exams and Tests
The health care provider may hear a fast heartbeat while listening to your heart with a stethoscope. Your pulse may feel fast, uneven, or both.
The normal heart rate is 60 - 100. In atrial fibrillation/flutter the heart rate may be 100 - 175. Blood pressure may be normal or low.
An ECG (a test that records the electrical activity of the heart) may show atrial fibrillation or atrial flutter.
If your abnormal heart rhythm comes and goes, you may need to wear a special monitor to diagnose the problem. The monitor records the heart's rhythms over a period of time.
- Event monitor
- Holter monitor (24-hour test)
- Implanted loop recorder
- Extended monitoring
Tests to find heart disease may include:
- Echocardiogram (ultrasound imaging of the heart)
- Tests to examine the blood supply of the heart muscle
- Tests to study the heart's electrical system
Cardioversion treatment is used to get the heart back into a normal rhythm right away. There are two options for treatment:
- Electric shocks to your heart
- Drugs given through a vein
These treatments may be done as an emergency, or planned ahead of time.
Daily medicines taken by mouth are used to:
- Slow the irregular heartbeat. These drugs may include beta-blockers, calcium channel blockers, and digoxin.
- Prevent atrial fibrillation from coming back. These drugs work well in many people, but they can have serious side effects. Atrial fibrillation returns in many people, even while they are taking these medicines.
Blood thinners are medicines that are used to reduce the risk of developing a blood clot that travels in the body (such as a stroke). They include heparin, warfarin (Coumadin), apixaban (Eliquis), rivaroxaban (Xarelto), and dabigatran (Pradaxa).
These drugs increase the chance of bleeding, so not everyone can use them. Antiplatelet drugs such as aspirin or clopidogrel may also be prescribed. Your doctor will consider your age and other medical problems when deciding which drugs are best.
A procedure called radiofrequency ablation can be used to scar areas in your heart where the heart rhythm problems are triggered. This can prevent the abnormal electrical signals that cause atrial fibrillation from moving through the heart. You may need a heart pacemaker after this procedure.
All people with atrial fibrillation will need to learn how to manage this condition at home.
Treatment can often control this disorder. Many people with atrial fibrillation do very well.
Atrial fibrillation tends to return and get worse. It may come back even with treatment.
Clots that break off and travel to the brain can cause a stroke.
When to Contact a Medical Professional
Call your health care provider if you have symptoms of atrial fibrillation or flutter.
Talk to your health care provider about steps to treat conditions that cause atrial fibrillation/flutter. Avoid binge drinking.
January CT, Wann LS, Alpert JS, et al. 2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation: A Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines and the Heart Rhythm Society. Circulation. 2014;129.
Morady F, Zipes DP. Atrial fibrillation: clinical features, mechanisms, and management. In: Bonow RO, Mann DL, Zipes DP, Libby P, eds. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 9th ed. Philadelphia, PA: Saunders Elsevier; 2011:chap 40.
Olgin J, Zipes DP. Specific arrhythmias: diagnosis and treatment. In: Bonow RO, Mann DL, Zipes DP, Libby P, eds. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 9th ed. Philadelphia, PA: Saunders Elsevier; 2011:chap 39.
Zimetbaum P. Cardiac arrhythmia with supraventricular origin. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine. 24th ed. Philadelphia, PA: Saunders Elsevier; 2011:chap 64.
Reviewed By: Michael A. Chen, MD, PhD, Associate Professor of Medicine, Division of Cardiology, Harborview Medical Center, University of Washington Medical School, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.