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Atrial fibrillation (AF) 101

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According to the American Heart Association, about 2.2 million Americans have a heart condition or rhythm called atrial fibrillation (AF). That makes it the most common heart rhythm abnormality. Here's what you should know about AF.

What is atrial fibrillation?

Did you know?

The likelihood of developing atrial fibrillation increases with age. Three to five percent of people over 65 have the condition.¹

Treating atrial fibrillation is an important way to help prevent stroke. Your chances of having a stroke are five times higher if you have AF.¹

Atrial fibrillation (AF) is a common heart rhythm in which there is an abnormally fast and chaotic heart rate in the heart's upper chambers (atria). In a normal heart, the heart's electrical system sends out a signal that tells your heart to beat. Normally, this signal comes from the sinoatrial node, or SA node, in the right atrium.

During AF, signals start irregularly from several areas in the atria. These disorganized electrical signals occur so quickly that only some of them are transferred to the ventricles. The atria quiver rapidly and irregularly, instead of beating in a regular rhythm. AF prevents the atria and ventricles from working together properly. This can decrease your heart's pumping by as much as 20 to 30 percent.

What are the symptoms of AF?

People with AF may experience one or more of the following symptoms:

Heart palpitations—sudden pounding, fluttering, or racing feeling in the chest
Lack of energy, feeling tired
Dizziness—a feeling of faintness or light-headedness
Chest discomfort—pain, pressure or discomfort in the chest
Shortness of breath

How is AF diagnosed?

An easy and reliable way to diagnose AF is to record an electrocardiogram (ECG) during an episode of AF. Since AF episodes can be unpredictable, an ECG that you record at your doctor's office may appear to be normal if AF is not present at the time. If this is the case, your doctor may ask you to wear a portable monitor (such as an event monitor or a Holter monitor), to record your heart's electrical signals. Your doctor then analyzes the monitor recordings to determine if you have AF.

What health risks are associated with AF?

If you have untreated AF, you may be at greater risk for stroke than someone with normal heart rhythms. Since blood does not flow through the atria smoothly, blood clots may form in the heart. If a blood clot is dislodged from the heart, it can travel through the bloodstream to the brain and result in a stroke.

In addition, untreated AF may lead to a condition known as heart failure. Heart failure is a progressive condition in which the heart muscle has been damaged by disease process or injury. This means it cannot pump enough blood and oxygen to meet the body's needs.

How is AF treated?

There are a number of treatments available for AF. Your doctor will choose a treatment for you based on your heart's rhythm, symptoms, and any other medical conditions you may have.

No matter which AF treatment you receive, the goals may include:

Restoring normal heart rhythm
Controlling the heart rate
Preventing stroke

Medication:

Digitalis, beta-adrenergic blockers, or calcium channel blockers may be used to control your heart rate. These medicines may relieve some of the symptoms associated with AF, but they may not prevent an AF episode. This means you may still be at risk for stroke and heart failure.

To help prevent stroke, your doctor may prescribe anticoagulant drugs that can reduce the formation of blood clots and lower your risk of stroke.

External cardioversion:

Cardioversion is a high-energy electrical shock delivered to the heart to restore a normal heart rhythm. It can be done externally using paddles placed on the chest or on the chest and back.

Ablation:

Ablation alters (ablates) targeted portions of your heart's electrical system or muscle. Your doctor delivers small amounts of energy to carefully selected portions of the heart muscle. This redirects the heart signals through the heart in a more controlled rate.

Ablation can be done as a type of surgery or as a procedure using a catheter (a flexible tube that is inserted into a blood vessel). In some cases, when ablation is done in certain parts of the heart, you may need a pacemaker afterward.

Implantable Cardioverter Defibrillator (ICD):

If you also have a ventricular arrhythmia (an electrical disturbance of the ventricles), your doctor may recommend a device called an ICD. Like a pacemaker, an ICD is implanted under the skin of the chest and connected to the heart with small flexible wires called leads (pronounced “leeds”). ICDs continuously monitor the heart's electrical activity and treat dangerously high heart rhythms in the ventricles. The ICD is able to determine if the fast rhythm is in the atrium such as AF, or if the rhythm is in the ventricle. With a lead in the atrium, the ICD may be able to record a fast rhythm in the atrium such as AF.

Surgical maze procedure:

The surgical maze procedure is an operation that is performed to stop AF by preventing disorganized electrical signals from traveling around the atria. After the procedure, you may need a pacemaker to help your heart beat regularly.

Take action

People can live with atrial fibrillation, but it can lead to other rhythm problems, chronic fatigue, heart failure and—worst of all—stroke. If you or someone you know has atrial fibrillation, talk with a doctor about the treatment options available.

AF patient goes from bedside to courtside after receiving pacemaker

Pat Ryan from Mountain View, Calif., was just 32 years old in 1968 when he suddenly began experiencing atrial fibrillation. After simply “living with” the condition for many years, Pat finally went on medication in 1984. By the time he was 55, however, medications could no longer control his condition. Pat was bedridden, unable to work and confined to his home.

“It (the atrial fibrillation) was a runaway train. I was in a constant state of flutter and fibrillation at over 180 beats a minute. I was also developing congestive heart failure.”

Pat's cardiologist determined that he needed an AV node ablation procedure, which is used when the heart rate effects of atrial fibrillation cannot be stopped. Since the ablation alters the entire AV node (which relays the heart's electrical signals from the atria to the ventricles), a pacemaker is needed after the surgery to regulate the heart's rhythm.

After the ablation and surgery to implant the pacemaker, Pat said his doctor wanted him to walk down to the end of the hall. “I wanted to RUN down there because I had a new life. I am serious—I had a new life. You just do not lead a normal life with your heart beating 180 beats a minute.”

After the surgery, with his doctor's approval, Pat started playing tennis within weeks. “I ended up playing competitive tennis. I could play about 2-1/2 to 3 hours of singles full blast, but I also had deteriorated a lot because I hadn't exercised a lot, so I had to build my body up. My wife Sue and I also played club tennis. We played mixed doubles and it was terrific. For me the pacemaker has just made all the difference in the world.”

Note: Individual symptoms, situations, results, and circumstances may vary. Please consult your doctor or qualified health provider regarding your condition and appropriate medical treatment. Your doctor will help decide what activities and activity level are right for you. The information provided is not intended to be used for medical diagnosis or treatment or as a substitute for professional medical advice .

^{Footnote:

1. American Heart Association website, www.americanheart.org , accessed May 27, 2008.}

Talk to your doctor about important safety information.

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