Why does atrial fibrillation occur

However, A-fib may cause a fast, pounding heartbeat palpitations , shortness of breath or weakness. Episodes of atrial fibrillation may come and go, or they may be persistent. Although A-fib itself usually isn't life-threatening, it's a serious medical condition that requires proper treatment to prevent stroke.

Treatment for atrial fibrillation may include medications, therapy to reset the heart rhythm and catheter procedures to block faulty heart signals. A person with atrial fibrillation may also have a related heart rhythm problem called atrial flutter. Although atrial flutter is a different arrhythmia, the treatment is quite similar to atrial fibrillation. Some people with atrial fibrillation A-fib don't notice any symptoms. Those who do have atrial fibrillation symptoms may have signs and symptoms such as:.

If you have chest pain, seek immediate medical help. Chest pain could mean that you're having a heart attack. To understand the causes of A-fib , it may be helpful to know how the heart typically beats. The typical heart has four chambers — two upper chambers atria and two lower chambers ventricles.

Within the upper right chamber of the heart right atrium is a group of cells called the sinus node. The sinus node is the heart's natural pacemaker. It produces the signal that starts each heartbeat. In atrial fibrillation, the signals in the upper chambers of the heart are chaotic. As a result, the upper chambers shake quiver. The AV node is then bombarded with signals trying to get through to the lower heart chambers ventricles.

This causes a fast and irregular heart rhythm. The heart rate in atrial fibrillation may range from to beats a minute. The normal range for a heart rate is 60 to beats a minute. Problems with the heart's structure are the most common cause of atrial fibrillation.

Possible causes of atrial fibrillation include:. In atrial fibrillation, the chaotic heart rhythm can cause blood to collect in the heart's upper chambers atria and form clots.

If a blood clot in the left upper chamber left atrium breaks free from the heart area, it can travel to the brain and cause a stroke. The risk of stroke from atrial fibrillation increases as you grow older. Other health conditions also may increase your risk of a stroke due to A-fib , including:. Blood thinners are commonly prescribed to prevent blood clots and strokes in people with atrial fibrillation.

Healthy lifestyle choices can reduce the risk of heart disease and may prevent atrial fibrillation. Here are some basic heart-healthy tips:. Atrial fibrillation care at Mayo Clinic.

Atrial fibrillation is generally not life threatening, many people live normal healthy lives with this condition, but it can be uncomfortable and often needs treatment. This condition increases your risk by about four to five times of having a transient ischaemic attack TIA or stroke.

This is because when the atria in the heart do not contract properly there is a risk of blood clot formation. Clots from the atria may break off and go to other parts of the body. A blood clot passing up to the arteries supplying the brain may cause a stroke.

For this reason, treatment may involve medication to control the heart rate or rhythm, and medication to prevent clots from forming in the blood. Find out how to treat atrial fibrillation and possible complications of having AF. The most obvious symptom of atrial fibrillation AF is palpitations caused by a fast and irregular heartbeat.

Some people with atrial fibrillation have no symptoms and it is only discovered during routine tests or investigations for another condition. The exact cause of atrial fibrillation AF is unknown, but it becomes more common with age and affects certain groups of people more than others.

Not everyone with atrial fibrillation falls into one of the above groups. Sometimes the cause can be idiopathic no known cause and can affect extremely athletic people. Feeling your pulse to check if you have an irregular heartbeat can give a strong indication of whether you have atrial fibrillation AF. However, a complete diagnosis requires a full medical investigation. If your GP thinks you have atrial fibrillation after assessing your symptoms, you will be asked to have an electrocardiogram ECG and referred to a heart specialist, known as a cardiologist.

Small stickers called electrodes are attached to your arms, legs and chest and connected by wires to an ECG machine. Every time your heart beats, it produces tiny electrical signals.

An ECG machine traces these signals on paper. It takes about five minutes and is painless. If you have the test during an episode of atrial fibrillation, the ECG will record your abnormal heart rate. This will confirm the diagnosis of atrial fibrillation and rule out other conditions. However, it may be difficult to capture an episode, as the irregular rhythm may 'come and go', therefore, to capture this your GP or cardiologist, may ask you to wear a small, portable ECG recorder for a longer period of time away from the hospital or GP surgery.

Find out more about having an ECG. It can help identify any other heart problems and assess the structure and function of your heart and valves. Find out more about having an echocardiogram.

A chest X-ray may be performed and will identify any lung problems that may have caused the atrial fibrillation. Blood tests can also be useful in the diagnosis of atrial fibrillation. They may show anaemia, which could be complicating the situation, problems with kidney function or hyperthyroidism overactive thyroid gland.

The first step is to try to find out the cause of the atrial fibrillation. If a cause is found, treatment for this may be enough. For example, medication to correct hyperthyroidism an overactive thyroid gland may cure atrial fibrillation.

Some people with atrial fibrillation may need more than one anti-arrhythmic medicine to control it. There are a number of drugs that can be used to try to restore a normal heart. It is important you know what side effects to look out for if taking such medication and seek medical advice if you experience any of them.

To find out about side effects, read the patient information leaflet that comes with your medicine for more details. The way the heart beats in atrial fibrillation means that there is a risk of blood clots forming in the heart chambers. If these get into the bloodstream, they can cause a stroke our complications of atrial fibrillation section has more information on this. Your doctor will assess your risk to minimise your chance of a stroke. They will consider your age and whether you have a history of any of the following:.

You will be classed as having a high, moderate or low risk of a stroke and will be given medication according to your risk. Depending on your level of risk, you may be prescribed warfarin. New anticoagulants such as dabigatran, rivoroxaban and apixaban have been developed which do not require dose changes and continuous blood test monitoring.

The use of these new drugs to reduce the risk of stroke in atrial fibrillation patients is likely to increase with time. Currently they tend to be reserved for patients who are intolerant of warfarin or are unable to obtain steady levels of blood thinning with warfarin.

Watch an animation of atrial fibrillation. If you or someone you love has atrial fibrillation, learn more about what AFib is, why treatment can save lives, and what you can do to reach your goals, lower your risks and live a healthy life. Written by American Heart Association editorial staff and reviewed by science and medicine advisers.

See our editorial policies and staff. Atrial Fibrillation. What is Atrial Fibrillation? Why Atrial Fibrillation Matters. Who is at Risk for Atrial Fibrillation?