Atrial fibrillation

The most common symptom is a pounding or racing heart (palpitations) that can be felt in the chest or neck. The person's pulse is then usually higher and less regular than normal. A healthy resting heart rate usually ranges between 60 and 90 beats per minute (bpm). Atrial fibrillation causes the heart rate to increase to between 120 and 160 bpm, and even up to 200 bpm in some people.

Other possible symptoms include feeling weak, becoming exhausted faster, chest tightness, light-headedness and dizziness. More than half of all people with atrial fibrillation don’t notice that they have it – at least at the start.

People with other heart problems may have additional symptoms. For instance, heart failure can lead to shortness of breath and exhaustion, particularly during physical activity.

Every time the heart beats, it contracts (squeezes) and pumps blood into the body. The heartbeat is regulated by electrical signals. The signal that starts a heartbeat is generated in the sinus node, which is found in the wall of the right atrium (the upper right chamber of the heart). This signal spreads like a wave across both atria (upper heart chambers), causing them to squeeze. The sinus node is sometimes described as the heart’s “natural pacemaker.” A normal heartbeat is known as the sinus rhythm.

In atrial fibrillation, the electrical signals spread across the upper chambers in a chaotic way. This makes them quiver (“fibrillate”) uncontrollably.

The upper chambers of the heart usually help the lower chambers (ventricles) to fill up with blood. In atrial fibrillation, the heart doesn’t have this extra pumping power. The lower chambers still pump blood into the body, but not as much and in a less regular rhythm.

Atrial fibrillation is usually caused by one of these cardiovascular diseases:

• High blood pressure
• Coronary artery disease
• Heart attack
• Heart failure (this is sometimes caused by atrial fibrillation instead)

Sometimes atrial fibrillation is caused by a treatable condition such as a leaky heart valve or an overactive thyroid gland. If that is the case, the atrial fibrillation might go away following heart valve surgery or thyroid treatment.

The biggest risk factor is older age.

If you have close relatives (parents, brothers or sisters) who have atrial fibrillation, you are more likely to develop it yourself. Men have a higher risk than women do. Atrial fibrillation is also more common in people with lighter skin than it is in people with darker skin.

The risk factors that you can influence include the following:

• Alcohol (drinking too much or too regularly)
• Smoking
• Diabetes
• High blood pressure
• Being very overweight
• Sleep apnea (pauses in breathing during sleep)

Atrial fibrillation is the most common type of abnormal heartbeat (arrhythmia). It is estimated that about 2% of the total population is affected. The risk increases with age, to 8% in people over the age of 65.

Atrial fibrillation typically occurs in rare, short episodes at first. Over time, it can then gradually progress to longer episodes or permanent atrial fibrillation. There are four different types, depending on how long the episodes last:

• In paroxysmal (“intermittent”) atrial fibrillation the heart rhythm usually returns to normal on its own within about 48 hours. It can sometimes last up to seven days, though. Paroxysmal atrial fibrillation may occur only once or keep coming back in episodes.
• Persistent atrial fibrillation lasts longer than seven days.
• Long-standing persistent atrial fibrillation lasts longer than a year.
• Permanent atrial fibrillation is always present.

But this classification can only serve as a rough guideline: It often isn’t clear whether someone has already had episodes of atrial fibrillation in the past, or how long they have already had it for.

Although atrial fibrillation can cause various noticeable symptoms, it is usually not an acutely life-threatening condition. But it can lead to various health problems in the long term. The main ones are:

• Heart failure (a weak heart, also known as cardiac insufficiency): If the atria (upper heart chambers) no longer squeeze properly, the rest of the heart has to work harder to provide the body with blood. This can become too much for the heart to handle, making it weaker over time. If someone already has heart failure, atrial fibrillation can make it worse.
• Stroke: In atrial fibrillation, the upper heart chambers no longer pump enough blood. As a result, it takes longer for blood to pass through these chambers and it builds up there. This increases the likelihood of blood clots forming. If a blood clot is carried to the brain in the bloodstream, it may block a blood vessel there and cause a stroke.

A person’s individual risk of stroke will depend on whether they have risk factors other than atrial fibrillation. People who have atrial fibrillation often have other medical conditions too, such as high blood pressure or coronary artery disease.

Various things can help to get an accurate diagnosis, find out the cause, and plan the treatment:

• A talk about your medical history (anamnesis): The doctor asks questions about your symptoms, other medical conditions, age and family history, as well as risk factors for heart disease.
• Physical examination: This includes measuring your pulse rate and blood pressure.
• Electrocardiogram (ECG): An ECG measures the electrical activity that regulates the heartbeat. This is a reliable way to diagnose atrial fibrillation. ECGs can be done when you are at rest, exercising or over a period of 24 hours (Holter monitor).
• Blood test: Blood tests can be used to check various things, including thyroid function. Atrial fibrillation is sometimes caused by an overactive thyroid gland, or taking too high a dose of thyroid medication. The electrolytes (salts and minerals) in your blood can be measured too. Atrial fibrillation is sometimes associated with an electrolyte imbalance.
• Ultrasound scan of the heart (echocardiography): This is commonly known as an “echo.” It can be used to, for example, see how big the heart chambers are and check for heart valve problems.

Some tests are particularly helpful when planning treatment: For example, kidney and liver function tests are important because some medications aren’t suitable for people with kidney or liver problems.

Because atrial fibrillation doesn’t always cause symptoms, it is sometimes discovered by chance, for instance if an ECG is done for a different reason.

There’s a lot you can do yourself to keep your heart healthy – which helps to prevent atrial fibrillation too:

• Quit smoking
• Get more exercise
• Lose weight (if you’re overweight)
• Eat less salt (if you have high blood pressure)
• Drink less alcohol

Research has shown, for instance, that people who have atrial fibrillation have fewer episodes if they generally avoid alcohol. One study also found that losing weight reduced the symptoms and frequency of atrial fibrillation episodes.

The treatments for atrial fibrillation have two main aims: One aim is to get rid of – or at least reduce – the symptoms caused by the irregular heartbeat. The other is to prevent strokes.

There are various options for achieving both of these aims:

It is sometimes enough to reduce the too-high heart rate with medication (rate control) – usually a beta blocker. This treatment takes the strain off the heart and helps to reduce the symptoms.

If that doesn’t make a big enough difference, doctors can try to restore the heart’s normal rhythm (rhythm control). This is usually done by delivering controlled electric shocks to the heart. But the rhythm of the heart may become irregular again afterwards. The risk of this happening can be reduced by treatment with medication or a procedure known as catheter ablation. This is a good idea if the atrial fibrillation has weakened the heart, for instance.

Most people who have atrial fibrillation are advised to take medication to prevent strokes. Medications called oral anticoagulants reduce blood clotting and can greatly lower the risk of a stroke.

It is best to talk with your doctor about whether or not to use anticoagulants, and decide together. Here it is a good idea to carefully weigh the pros (stroke prevention) and cons (risk of bleeding). Your personal risk of a stroke and bleeding will depend on your personal risk factors Special calculators can help to determine your risk.

Besides treating the symptoms and preventing a stroke, it is also important to treat any other medical conditions, such as high blood pressure or coronary artery disease.

Most people aren’t aware of their heart if it beats normally. That’s different in people who have atrial fibrillation: They notice that their heart is not beating as it should. Many find this so worrying that they see a doctor about it. Being diagnosed with atrial fibrillation might come as a shock at first, but the symptoms can usually be effectively managed using various treatments. Patient education courses can be helpful too: Here people can learn how to cope with the condition in everyday life, and how to use their anticoagulant medication properly. The doctor will help you to apply for patient education.

But many people still feel worried. Some wonder whether they should try to avoid strenuous activities, and whether they can continue living as usual and do things like sports. There’s no medical reason not to. Research has even shown that moderate exercise can improve your physical fitness. It’s best to talk to your doctor about which type of exercise would be suitable.

There are various sources of support for people who have cardiovascular (heart and blood vessel) disease. These include support groups and information centers. Support services in Germany are often organized quite differently from region to region, though. Our list may help you to find useful places to turn to.

When people are ill or need medical advice, they usually go to see their family doctor first. In our "Health care in Germany" topic you can read about how to find the right doctor – and our list of questions can help you to prepare for your appointment.