Atrial Fibrillation = Upper chambers of the heart quiver
The heart's two small upper chambers (the atria) quiver (like shaking a bowl of gelatin), instead of beating rhythmically and effectively.
How it happens
Many parts of the atria (the heart's two upper chambers) start emitting uncoordinated electrical signals. The atria pump too fast , unevenly (irregularly) and won't fully contract (squeeze blood out of the heart completely). Some electrical signals go to the ventricles, which still pump out blood. But blood isn't pumped completely out of them, so it may pool and clot. If a piece of a blood clot in the atria leaves the heart and becomes lodged in an artery in the brain, a stroke results.
Watch an animation of atrial fibrillation
Who is more likely to have atrial fibrillation?
An estimated 2.2 million Americans are living with AF. It’s the most common "serious" heart rhythm abnormality in people over the age of 65 years.
- Likelihood increases with age.
- Men are slightly more likely than women to develop AF, but women diagnosed with it carry a longer-term risk of premature death.
- Smokers.
- People who use stimulant drugs (including caffeine).
- People with:
- hyperthyroidism (too much thyroid hormone)
- diabetes
- high blood pressure
- excessive alcohol consumption
- coronary heart disease/heart attack
- heart failure
- heart valve disease
- inflamed heart muscle or lining (endocarditis)
- recent heart surgery
- atherosclerosis (arteries lined with fatty deposits)
- angina (chest pain due to reduced blood flow to the heart muscle)
- congenital heart defects
- chronic lung disease
- pulmonary blood clots
- emphysema
- asthma
Symptoms of atrial fibrillation
Some people with AF don't feel a thing. Others notice an irregularity immediately. Symptoms may include:
- Racing, uncomfortable, irregular heartbeat
- "Flopping," fluttering or thumping feeling in your chest
- Heart palpitations
- Dizziness
- Sweating
- Chest pain or pressure
- Difficulty getting your breath
- Overall weakness
- Fainting
- Fatigue during exercise.
Consequences of atrial fibrillation
AF isn't life-threatening in and of itself, but it can lead to other serious medical problems, including:
- Stroke: Your chances of having a stroke are five times higher if you have AF.
- Additional heart rhythm problems
- Heart failure
- Chronic fatigue
Treatments for atrial fibrillation
The goals of atrial fibrillation treatment plans are to:
- Control heart rate and restore normal rhythm
- Prevent blood clots
- Reduce stroke risk
- Control heart rate and restore normal rhythm with:
- Medications may prescribed or administered by healthcare professionals to slow down rapid heart rate.
- Electrical cardioversion is a procedure used to attempt to get the heart beat back to normal rhythm) through electric shock. It may be used when medication doesn't improve symptoms.
- Radiofrequency ablation may be effective in some patients when medications don't work. In this procedure, thin and flexible tubes are introduced through a blood vessel and directed to the heart muscle. Then a burst of radiofrequency energy is delivered to destroy tissue that triggers abnormal electrical signals or to block abnormal electrical pathways.
- Surgery can be used to disrupt electrical pathways that generate AF.
- Atrial pacemakers can be implanted under the skin to regulate the heart rhythm.
- Prevent blood clots with anticoagulant and antiplatelet medications (such as warfarin and aspirin)
- Warfarin is more effective than aspirin in preventing strokes caused by blood clots, but warfarin has more side effects than aspirin (potential bleeding problems or ulcer).
- Aspirin may be recommended in persons under the age of 65 years with no risk factors and just atrial fibrillation alone.
- Manage other risk factors for stroke
This content is reviewed regularly. Last update 02/11/09.
