What is atrial fibrillation (A-Fib)?
Atrial fibrillation is a disorder found in about 2.2 million Americans. During atrial fibrillation, the heart's two small upper chambers (the atria) quiver instead of beating effectively. 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. About 15 percent of strokes occur in people with atrial fibrillation.
The likelihood of developing atrial fibrillation increases with age. Three to five percent of people over 65 have atrial fibrillation.
Signs & Symptoms of A-Fib
Atrial fibrillation (A-Fib) usually causes the ventricles to contract faster than normal. When this happens, the ventricles don't have enough time to fill completely with blood to pump to the lungs and body.
This inefficient pumping can cause signs and symptoms, such as:
- Palpitations (feelings that your heart is skipping a beat, fluttering, or beating too hard or fast)
- Shortness of breath
- Weakness or difficulty exercising
- Chest pain
- Dizziness or fainting
- Fatigue (tiredness)
A-Fib has two major complications: stroke and heart failure. During A-Fib, the atria don't pump all of their blood to the ventricles. Some blood pools in the atria. When this happens, a blood clot (also called a thrombus) can form. If the clot breaks off and travels to the brain, it can cause a stroke. (A clot that forms in one part of the body and travels in the bloodstream to another part of the body is called an embolus.) Blood-thinning medicines to reduce the risk of stroke are a very important part of treatment for people who have A-Fib.
*Information from National Heart, Lung and Blood Institute
How is atrial fibrillation treated?
Several approaches are used to treat and prevent abnormal beating:
- Medications are used to slow down rapid heart rate associated with A-Fib. These treatments may include drugs such as digoxin, beta blockers, amiodarone, disopyramide, calcium antagonists, sotalol, flecainide, procainamide, quinidine, propafenone, etc.
- Electrical cardioversion may be used to restore normal heart rhythm with an electric shock, when medication doesn't improve symptoms.
- Drugs (such as ibutilide) can sometimes restore the heart's normal rhythm. These drugs are given under medical supervision, and are delivered through an IV tube into a vein, usually in the patient's arm.
- 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 A-Fib.
- Atrial pacemakers can be implanted under the skin to regulate the heart rhythm.
Treating Atrial Fibrillation & Stroke Prevention:
Treating atrial fibrillation is an important way to help prevent stroke. That's why the American Heart Association recommends aggressive treatment of this heart arrhythmia.
Drugs are also used to help reduce stroke risk in people with A-Fib. Anticoagulant and antiplatelet medications thin the blood and make it less prone to clotting. Warfarin is the anticoagulant now used for this purpose, and aspirin is the antiplatelet drug most often used. Long-term use of warfarin in patients with AF and other stroke risk factors can reduce stroke by 68 percent.
- Physicians differ on the choice of drugs to prevent embolic stroke - stroke caused by a blood clot. It's clear that warfarin is more effective against this type of stroke than aspirin.
- However, warfarin has more side effects than aspirin. Examples include potential bleeding problems or ulcer.
- Patients at high risk for stroke should probably be treated with warfarin rather than aspirin unless there are clear reasons not to do so.
- Aspirin is the standard treatment for patients at low risk for stroke and under 75 years of age.
*Information from the American Heart Association
Risk Factors for A-Fib
As with many health conditions, the prevalence of A-Fib increases with age. According to the Mayo Clinic, fewer than one in every 100 people in their 50's has A-Fib, but about 10 out of every 100 in their 80's experience it. The most common cause of atrial fibrillation is longstanding, uncontrolled high blood pressure and heart disease. Additionally, atrial fibrillation is the most common complication after heart surgery.
An entire spectrum of seemingly unrelated conditions can send the atria into "overdrive." Other contributing factors include:
- Heart valve disease
- Coronary artery disease
- Cardiomyopathy with weakened heart muscle
- Chronic obstructive pulmonary disease (COPD)
- Chronic lung disease
- Excessive alcohol consumption
- Cigarette or stimulant use (such as caffeine)
- Periods of extreme stress or fatigue can trigger episodes of A-Fib
Living with A-Fib
People who have atrial fibrillation (A-Fib) -even permanent AF- can live normal, active lives. If you have A-Fib, ongoing medical care is important.
Keep all your medical appointments. Bring all the medicines you're taking to every doctor and emergency room visit. This will help your doctor know exactly what medicines you're taking.
Follow your doctor's instructions for taking medicines. Be careful about taking over-the-counter medicines, nutritional supplements, and cold and allergy medicines. Some of these products contain stimulants that can trigger rapid heart rhythms. Some over-the-counter medicines can have harmful interactions with heart rhythm medicines.
Tell your doctor if your medicines are causing side effects, if your symptoms are getting worse, or if you have new symptoms.
If you're taking blood-thinning medicines, you'll need to be carefully monitored. For example, you may need regular blood tests to check how the medicines are working.
Talk with your doctor about diet, physical activity, weight control, and alcohol use. Find out what steps you can take to manage your condition.
*Information from National Heart, Lung and Blood Institute