An Overview of Atrial Fibrillation

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Atrial fibrillation is a fast and very irregular heart rhythm. While atrial fibrillation (a-fib) is not itself life-threatening, it often causes significant symptoms, including palpitations, shortness of breath, and easily becoming fatigued. It can lead to more serious problems, especially stroke, and (in people with heart disease), worsening heart failure. Several treatment options are available for atrial fibrillation, but choosing the best treatment plan is not always straightforward. If you have atrial fibrillation, you should try to learn everything you can about this arrhythmia—its symptoms, its causes, and the available treatments—so you can work with your doctor to decide which therapeutic approach is right for you.


Atrial fibrillation is a fast and very irregular heart rhythm, caused by extremely rapid and chaotic electrical impulses originating in the heart's atria (the two upper cardiac chambers). This kind of rapid, chaotic electrical activity in the heart is called "fibrillation." When the atria begin fibrillating, three things can happen:

First, the heart rate tends to become rapid and irregular. The AV node is bombarded with frequent, irregular electrical impulses coming from the atria. Many of these impulses—as many as 200 per minute or more—are transmitted to the ventricles. This results in a fast and very irregular heartbeat. The rapid, irregular heartbeat often produces disturbing symptoms.

Second, when the atria are fibrillating, they are no longer beating effectively. So the normal coordination between the atria and the ventricles is lost. As a result, the heart works less efficiently, and eventually may begin to fail.

Third, because the atria are no longer contracting effectively, after a time (usually after about 24 hours or so) blood clots can begin to form in the atria. These blood clots can eventually break off and travel to various parts of the body, such as the brain.

While atrial fibrillation itself often produces significant symptoms, its real significance is that it puts you at risk for medical conditions that can be permanently disabling or fatal.


Most people with atrial fibrillation experience significant symptoms. The arrhythmia tends to be very noticeable and quite disturbing. The most common symptoms are palpitations, which are usually perceived as feeling a rapid, irregular heartbeat, or perhaps as “skipped” beats. People with atrial fibrillation also commonly experience easy fatiguability, shortness of breath, and (occasionally) light-headedness. These symptoms, directly related to the atrial fibrillation itself, can often be particularly disturbing in people who have diastolic dysfunction, or hypertrophic cardiomyopathy.

However, atrial fibrillation can occur without producing any symptoms at all. While not having symptoms is generally a good thing, having “silent” atrial fibrillation can be dangerous—since it can produce medical problems whether or not the arrhythmia itself is causing significant symptoms. It can lead to more frequent or intense angina in people who have CAD or a substantial deterioration in cardiac function in people with heart failure.

In fact, if a very rapid heart rate caused by atrial fibrillation persists long enough (for at least several months), the heart muscle can begin to weaken, and heart failure can occur—even in people whose hearts are otherwise normal.

The most dire consequence of atrial fibrillation, however, is the possibility of stroke. Untreated atrial fibrillation substantially increases the risk of stroke. As many as 15 percent of all strokes are thought to be caused by atrial fibrillation. Furthermore, many people who have suffered strokes for no apparent reason (so-called cryptogenic strokes) turn out to have episodes of “silent” atrial fibrillation.


Atrial fibrillation can be produced by several cardiac conditions, including coronary artery disease (CAD)mitral regurgitation, chronic hypertensionpericarditis, heart failure, or virtually any other kind of heart problem. This arrhythmia is also fairly common with hyperthyroidismpneumonia, or pulmonary embolus.

Ingestion of amphetamines or other stimulants (such as cold remedies containing pseudoephedrine) can cause atrial fibrillation in some people, as well as after drinking as few as one or two alcoholic beverages—a condition known as "holiday heart." While doctors have traditionally said caffeine also causes atrial fibrillation, recent evidence from clinical studies shows that, in most people, it does not.

A large proportion of people with atrial fibrillation have no particular identifiable reason for it. They are said to have "idiopathic" atrial fibrillation. Idiopathic atrial fibrillation is often a condition associated with aging. While atrial fibrillation is rare in patients under 50, it is quite common in people who are 80 or 90 years old.

Newer studies have shown atrial fibrillation is related to lifestyle in many cases. For instance, people who are overweight and sedentary have a much higher risk of atrial fibrillation. In people who have atrial fibrillation related to lifestyle choices, an intensive program of lifestyle modification has been shown to help eliminate the arrhythmia.


The diagnosis of atrial fibrillation is usually straightforward. It simply requires recording an electrocardiogram (ECG) during an episode of atrial fibrillation. This requirement does not present a problem in people with chronic or persistent atrial fibrillation, in whom the arrhythmia is likely to be seen any time an ECG is taken.

However, in people whose atrial fibrillation occurs intermittently, long-term ambulatory ECG monitoring may be required to make the diagnosis. Long-term ECG monitoring may be especially useful in people who have had cryptogenic strokes, since treating atrial fibrillation (if it is present) may help to prevent a recurrent stroke.

Doctors classify atrial fibrillation into different types. In fact, several confusing classification systems for atrial fibrillation have been used. To help you decide which treatment approach is right for you, it is useful to lump the types of atrial fibrillation into only two types:

  • New onset or intermittent atrial fibrillation. Here, atrial fibrillation is either a brand-new problem, or a problem that occurs only intermittently. Intermittent atrial fibrillation is often called "paroxysmal atrial fibrillation." People in this category have a normal heart rhythm the vast majority of the time, and their episodes of atrial fibrillation tend to be relatively brief and usually infrequent.
  • Chronic or persistent atrial fibrillation. Here, atrial fibrillation is either present all the time, or it occurs very often—such that periods of normal heart rhythm are relatively infrequent or short-lived.


If it were very easy and very safe to do so, it seems obvious that the best treatment for atrial fibrillation would be to restore and maintain the normal heart rhythm. Unfortunately, in many cases, it is neither particularly safe nor particularly easy.

Especially if atrial fibrillation has been present for weeks or months, it is exceedingly difficult to maintain a normal rhythm for more than a few hours or days. This unfortunate fact has required two different general treatment approaches for atrial fibrillation. The first is the “rhythm-control” approach, and the second is the “rate-control” approach.

The ”rhythm control" approach attempts to restore and maintain a normal heart rhythm. It is more likely to work in people with recent-onset or intermittent atrial fibrillation, and much less likely to be effective in people whose arrhythmia is chronic or persistent. The rhythm control method usually requires either the use of antiarrhythmic drugsablation therapy, or both.

The “rate control” approach to atrial fibrillation abandons the attempt to restore and maintain a normal heart rhythm. Atrial fibrillation is accepted as the new "normal" heart rhythm, and therapy is aimed at controlling the heart rate in order to minimize any symptoms being caused by the atrial fibrillation. Treatments include heart rate control medications such as digitalis, beta-blockers, and calcium channel blockers. Long-term studies have shown that clinical outcomes with the rate-control approach tend to be at least as favorable as the rhythm-control approach.

Whichever therapeutic approach is chosen, an important additional feature of treating atrial fibrillation is to take the necessary steps to minimize the risk of stroke. This usually requires taking anticoagulant drugs, but there are other treatment alternatives as well, including surgery or a catheter procedure to isolate the left atrial appendage (a “pouch” of the left atrium that is left over from fetal development).

Lifestyle changes are an important component of treatment, aimed at reducing both symptoms and risks of stroke or heart disease.

Deciding on the right treatment is the most important issue with atrial fibrillation. It can be a relatively complex choice, and it is one that ought to be tailored to each individual. The more you understand about it, the more you will be able to help your doctor make the treatment decisions that are right for you.


For the large majority of people with atrial fibrillation, the hard part comes in the weeks or months after the diagnosis, while you are in the midst of making the tough decisions on the right treatment approach, and then while your treatment is being instituted. It is natural and normal to feel fear, anxiety, anger, or sadness.

Reducing stress, losing excess weight, eating a heart-healthy diet, and other lifestyle changes will not only help you cope with your diagnosis, they also are often part of the recommended treatment and can reduce your symptoms. Whether it is you or a loved one who has a-fib, making these healthy changes together can give the best chance of success.

A Word From Verywell

Keep in mind that millions of people are living completely normal lives despite having atrial fibrillation. That should be your goal, too. While arriving at the right treatment decision can be a challenge, and while administering your treatment might take some time and effort, once your treatment is settled upon you should get back to living your regular life (perhaps with some favorable lifestyle changes). This should be your expectation. And as you discuss your treatment options with your doctor, make sure he or she has the same expectation for you as well.

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