Atrial Fibrillation

What is atrial fibrillation?

Atrial fibrillation (a-fib) is a change in your heart rhythm. It causes an irregular heartbeat. Sometimes the heartbeat may be very fast.

What is the cause?

There are 4 chambers of the heart: 2 upper chambers (atria), and 2 lower chambers (ventricles). An electrical impulse in your heart starts each heartbeat, and normally all 4 chambers beat in a regular pattern. When you have atrial fibrillation, the upper chambers beat very quickly and not in a normal pattern.

Common causes of atrial fibrillation are:

• heart disease, including coronary artery disease, heart enlargement due to many years of high blood pressure, and heart failure from other causes, including congenital heart disease
• problems with a heart valve, such as damage to the mitral valve (located between the upper and lower left heart chambers), usually by rheumatic fever or mitral valve prolapse

Other causes of atrial fibrillation include:

• an overactive thyroid gland
• pneumonia
• chronic lung disease
• heavy drinking of alcohol

Sometimes no cause for atrial fibrillation can be found.

What are the symptoms?

Some people don’t have any symptoms. When atrial fibrillation does cause symptoms, the most common ones are:

• fast or irregular heartbeat that may feel like a sudden pounding, fluttering, or racing in the chest
• shortness of breath
• chest pain or a sense of pressure in the chest
• extreme weakness or tiredness and an irregular pulse
• lightheadedness or dizziness
• confusion
• passing out without warning

If you have any of these symptoms you should seek immediate medical attention because atrial fibrillation can be dangerous. For example, it can be a problem if you pass out or become weak and confused while you are driving. Sometimes atrial fibrillation can cause heart attack or stroke.

How is it diagnosed?

Your healthcare provider will ask about your symptoms and examine you. You may have blood tests. The diagnosis can be confirmed with an electrocardiogram (ECG). An ECG measures the electrical activity of your heart. It shows a special pattern when you are having atrial fibrillation. Sometimes atrial fibrillation comes and goes before it can be seen on an ECG. In this case, you may have to wear a Holter monitor or event recorder to record your heart rate. The Holter monitor is a portable ECG used to detect heart rhythm problems.

You may also have an echocardiogram. This test uses sound waves to make images of your heart. It is a way to check for problems with the structure of the heart, such as an abnormal mitral valve.

How is it treated?

Atrial fibrillation may also cause a stroke, heart attack, or heart failure. Treatment depends on:

• the cause of the fibrillation
• your medical history
• the severity of your symptoms

If your healthcare provider finds a medical problem that is causing the atrial fibrillation, you will be treated for the underlying problem.

Your provider may prescribe a medicine to slow or restore normal heart rate and rhythm, such as:

• beta blockers
• digoxin
• calcium channel blockers, such as diltiazem and verapamil

When the heart beats irregularly, the blood is not completely pumped out of the atria and it may pool or clot. This increases your risk of having a stroke or heart attack from a blood clot. Your healthcare provider may prescribe an anticoagulant (blood thinner), such as warfarin (Coumadin) or dabigatran (Pradaxa), to lower your risk of blood clots.

When symptoms are severe, you may need to have your heart put back to a normal rhythm. This may be done with:

• anti-arrhythmic medicines, such as Sotalol (Betapace) and amiodarone (Cordarone)
• a procedure called electrical cardioversion

If you have electrical cardioversion, first an anesthetic will be given to you to keep you from feeling pain during the procedure. Then an electrical shock will be applied to your chest. The electrical shock will make your heart start beating normally again.

If you keep having atrial fibrillation, your healthcare provider might suggest a procedure called ablation. Ablation delivers radio waves to the inside of the heart to destroy small areas in the heart and block abnormal electrical pathways. For a type of ablation called AV nodal ablation, a pacemaker will be implanted in your chest so your heart can have a normal rhythm.

How long will the effects last?

For some people atrial fibrillation lasts just a short time and the heart goes back to a normal rhythm on its own. If you keep having spells of atrial fibrillation, medicines to control heart rate may help keep you from having more spells, or you may have them less often. In some cases you may stay in atrial fibrillation permanently but if your heart rate is controlled with medicine, the atrial fibrillation may not bother you much and you should be able to do your usual activities.

If you have a medical problem that is causing atrial fibrillation, usually your heart rhythm will go back to normal with treatment of the underlying problem.

How can I take care of myself?

• Take your medicines as prescribed.
• If you take an anticoagulant, keep your appointments for follow-up blood tests. Make sure your healthcare provider knows about changes in your diet or medical condition. Your provider also needs to know about any other medicines you are taking, including nonprescription medicines and supplements.
• If you are not taking warfarin, ask your provider if he or she recommends that you take an aspirin every day. Aspirin can help lower the risk of blood clots in the heart.
• Although an occasional alcoholic or caffeinated drink is usually OK, you may find that too much alcohol or caffeine can trigger symptoms. If so, you may need to avoid alcohol or caffeine.
• Make sure your healthcare provider knows about all prescription and nonprescription medicines, herbs, or supplements that you are taking. Some medicines may interact with your anticoagulant medicine or increase your risk for atrial fibrillation.
• Contact your healthcare provider right away if you have any new symptoms, such as falling or fainting, or any symptoms that come back.

How can I help prevent atrial fibrillation?

The best prevention is to have a heart-healthy lifestyle.

• Keep a healthy weight.
• Eat a healthy diet that is low in sodium and saturated and trans fat.
• Stay fit with the right kind of exercise for you.
• Decrease stress.
• Don’t smoke.
• Limit your use of alcohol.

If you have heart disease or high blood pressure, follow your healthcare provider's advice closely.