Atrial fibrillation

The most common indications of atrial fibrillation are palpitations and a pounding heartbeat that is often too fast. The condition is not immediately life-threatening but does increase the risk of stroke and can permanently weaken the heart. Atrial fibrillation can be treated in various ways.

At a glance

  • With atrial fibrillation, the signals that regulate the heartbeat are disrupted.
  • The heart is no longer able to pump as much blood around the body.
  • Atrial fibrillation is generally the result of another chronic condition, such as high blood pressure or coronary heart disease.
  • In some cases, the cause of atrial fibrillation is unclear.
  • There are various ways to treat atrial fibrillation.

Note: The information in this article cannot and should not replace a medical consultation and must not be used for self-diagnosis or treatment.

Atrial fibrillation: older man having his heart examined by a doctor with a stethoscope.

What is atrial fibrillation?

With atrial fibrillation, the signals that regulate the heartbeat are disrupted. As a result, the heart frequently beats too quickly and inconsistently. This means that it is no longer able to pump as much blood around the body. Patients can feel faint or have symptoms such as clearly noticeable palpitations.

Atrial fibrillation is generally the result of another chronic condition, such as high blood pressure or coronary heart disease. In some cases, no clear cause can be found.

Atrial fibrillation is the most common form of cardiac arrhythmia. It is not immediately life-threatening but increases the likelihood of a stroke and can also weaken the heart in the long term.

What are the symptoms of atrial fibrillation?

The most common indication of atrial fibrillation is a clearly noticeable pounding heart (“palpitations” to use the medical term). This generally means that the heart beats faster and more irregularly than usual. The heart rate with atrial fibrillation can be far higher than the healthy resting rate of between about 60 and 100 beats per minute.

People with atrial fibrillation can also feel weak, dizzy or light-headed. However, up to 30 in every 100 people have no symptoms or only inconclusive symptoms that do not directly indicate atrial fibrillation. In some cases, people do not notice atrial fibrillation at all.

People who have atrial fibrillation alongside other heart conditions can also have additional symptoms. In the case of heart failure, for example, atrial fibrillation can noticeably reduce the heart’s performance. This can result in symptoms such as a shortness of breath and exhaustion, especially during physical exertion.

What are the causes of atrial fibrillation?

There are a number of causes of atrial fibrillation: high blood pressure, coronary heart disease, heart failure, heart attack and a heart valve defect

When the heart beats, the heart muscles rhythmically contract. The heartbeat is regulated by an electrical conduction system. The sinus node generates the signal for a new heartbeat. This is sometimes also referred to as the heart’s “natural pacemaker” and is a cluster of special cells in the wall of the right atrium. The electrical signals from the sinus node are transmitted along the conduction pathways to the atrioventricular node (AV node) and then on to the heart’s chambers. A normal heartbeat is also known as the sinus rhythm.

In people with atrial fibrillation, irregular electrical signals quickly spread through the upper chambers (atria). The sinus node is inactive during atrial fibrillation. As a result, the atria no longer contract and relax in a steady rhythm. Instead, they quiver rapidly and uncontrollably: they “fibrillate”.

The upper chambers of the heart normally help the lower chambers (ventricles) to quickly fill up with blood. They provide about 20% of the heart’s total pumping power. Atrial fibrillation reduces the heart’s performance. The lower chambers still pump blood through the body, but irregularly.

Atrial fibrillation can have several causes, the most common of which include:

An overactive thyroid gland and certain medication can also cause atrial fibrillation.

In about a third of people with atrial fibrillation, no clear cause can be determined.

What are the risk factors of atrial fibrillation?

The likelihood of atrial fibrillation increases with age. According to estimates, about 2% of the total population and about 7% of over-65-year-olds are affected.

The risk factors for atrial fibrillation include high or frequent alcohol consumption, smoking, diabetes mellitus, high blood pressure, being heavily overweight and sleep apnea. Some of these risk factors are things that people can influence themselves.

How does atrial fibrillation progress?

Atrial fibrillation usually starts with rare, short episodes. Over time, longer episodes may occur or the fibrillation may persist permanently. There are four different types, depending on the length of the episodes:

  • With “intermittent” (paroxysmal) atrial fibrillation, the heart rhythm usually returns to normal of its own accord and without treatment within about 48 hours. However, this type can also last for up to 7 days. Intermittent atrial fibrillation can occur as a one-off or repeatedly.
  • Persistent atrial fibrillation lasts more than seven days.
  • Long-standing persistent atrial fibrillation lasts for over a year.
  • Permanent atrial fibrillation does not usually go away again.

Classification into these four types is limited in its meaning though as it is often not clear whether atrial fibrillation has occurred before or how long it has been present. It is also sometimes possible for permanent atrial fibrillation to recede and then return intermittently.

Important: All four types of atrial fibrillation increase the risk of a stroke. The classification into different types therefore only plays a minor role in the decision as to whether or not treatment with anticoagulant drugs is required.

How is atrial fibrillation diagnosed?

As atrial fibrillation does not always have symptoms, it can sometimes be detected by chance. For example, if the electrical signals to the heart are investigated due to another condition. Several investigative methods can be used to obtain a precise diagnosis, determine the causes and plan the treatment:

  • Recording the medical history (anamnesis): the doctor asks about symptoms, pre-existing medical conditions, age and family history, as well as risk factors for heart conditions.
  • Physical examination: for example, heart rate and blood pressure measurements.
  • Electrocardiogram (ECG): ECGs can diagnose atrial fibrillation with a high degree of certainty. During this process, several electrodes are attached to the body to measure the electrical signals to the heart.
  • Blood test: blood tests can be used to assess thyroid function among other things. An overactive thyroid gland or an overdose of thyroid medication can cause atrial fibrillation.
  • Echocardiography: this procedure examines the heart using ultrasound. This makes it possible to check its pumping power, for example. However, echocardiography can also be used to detect more rare causes of atrial fibrillation, such as certain heart valve problems.

Other tests are mainly used to help plan treatment. For example, kidney and liver function can be determined because some medication is not suitable for people with kidney or liver weaknesses.

How is atrial fibrillation treated?

People with atrial fibrillation face several treatment decisions. First is the question of how the irregular heartbeat should be treated. The primary goal is to control the heart rate to an extent that alleviates the symptoms and takes the strain off the heart. Attempts can also be made to restore the heart’s normal rhythm (sinus rhythm).

There are two treatment strategies in this regard:

  • Heart rate control: the excessively high heart rate is permanently reduced with medication, usually a beta blocker. No attempts are made to eliminate the atrial fibrillation.
  • Heart rhythm stabilization: this strategy attempts to restore and stabilize the heart’s normal rhythm. This is usually done in a hospital by delivering controlled electric shocks. Treatment with medication usually follows to prevent relapses.

Heart rate control is usually the preferred treatment as it is less complicated and has a lower risk of side effects. Treatment to stabilize the heart’s rhythm is particularly useful in cases where heart rate control treatment is unable to sufficiently alleviate the symptoms.

People with atrial fibrillation also have to decide whether they want to take medication to reduce the risk of stroke and if so, which. Oral anticoagulants inhibit blood clotting and can reduce the risk of stroke very effectively.

More detailed information, for example on the prevention of strokes, can be found at

Important: In some cases there are significant reasons why anticoagulants should not be used for treatment despite a high risk of stroke, for example if there is a very high risk of bleeding. Here, the risk of stroke can be reduced through heart surgery. During this procedure, an “atrial appendage closure” is inserted into the left atrial appendage. However, these treatment procedures have not yet been sufficiently tested and can lead to serious complications.

In rare cases, atrial fibrillation itself can be life-threatening and cause the blood pressure to drop sharply, for example. The heart’s rhythm can usually be quickly restored using controlled electric shocks.

What other useful information is there about atrial fibrillation?

If the heart beats normally, you do not generally notice it. Atrial fibrillation can change this: in many cases, patients feel that their heart is no longer beating properly. This is often so concerning that they consult their doctor. If atrial fibrillation is found, many people are initially very worried. However, this condition and its symptoms can usually be treated easily. Training courses can also be helpful for people with atrial fibrillation: they show how people can deal with the condition during everyday life and adjust their own medication.

However, many people with atrial fibrillation still have concerns. Some wonder if they need to be more cautious now or can still lead as active a life as usual, for example by doing sport. Studies suggest that those affected should not worry and indicate that moderate physical activity does not harm people with atrial fibrillation but can improve their fitness.

In cooperation with the Institute for Quality and Efficiency in Health Care (Institut für Qualität und Wirtschaftlichkeit im Gesundheitswesen) (IQWiG).

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