Atrial Fibrillation (AFib): Symptoms, Causes, Tests and Treatment

Atrial fibrillation, often shortened to AFib or AF, is a common heart rhythm problem. It can come and go or be constant, and some people do not notice it at all. This article explains what the NHS and the US CDC say about it.

What is atrial fibrillation?

The NHS says AF is a heart rhythm problem in which the heartbeat is not steady, caused by a fault in the heart's electrical system. The CDC describes it as the most common type of treated arrhythmia, meaning the heart beats too slowly, too fast or in an irregular way. In AF, the upper chambers beat irregularly and blood does not flow into the lower chambers as well as it should. The NHS says there is currently no cure, but treatment can help manage symptoms and lower the risk of complications.

The NHS describes three patterns: paroxysmal AF, where symptoms start and stop; persistent AF, where symptoms stop after treatment; and permanent AF, where symptoms are always present.

Symptoms

Some people have no symptoms and find out during a routine check or other tests. The NHS lists these possible signs:

• An irregular pulse
• Palpitations, such as pounding, racing, fluttering or skipping, lasting seconds to minutes
• A heartbeat faster than 100 beats per minute
• Tiredness and difficulty exercising
• Chest pain or tightness
• Breathlessness, light-headedness, dizziness or feeling faint

Causes and risk factors

The NHS says AF is more likely if you are 55 or older, male, overweight, a smoker, or do endurance sports. Other conditions can be involved, including high blood pressure, heart failure, mitral valve problems, a previous heart attack, chronic kidney disease, an overactive thyroid, diabetes and sleep apnoea. Some medicines can also play a part, so ask your doctor and check medicine leaflets. Triggers can include caffeine, spicy food, stress, dehydration, lack of sleep and very hard exercise.

The CDC says high blood pressure accounts for about 1 in 5 cases, and also lists moderate to heavy alcohol use and enlargement of the left-side heart chambers.

AFib and stroke

The CDC says AFib raises stroke risk. After accounting for standard stroke risk factors, it was associated with about a fivefold increase in ischaemic stroke, and it causes about 1 in 7 strokes. The CDC says these strokes tend to be more severe. The NHS lists stroke as a possible complication and says medicines called anticoagulants are used to lower the risk of blood clots and stroke.

How is it diagnosed and treated?

If AF is suspected, the NHS says a GP refers you to a heart specialist, who asks about symptoms, checks your heart rate and may arrange an ECG, an echocardiogram, a chest X-ray and blood tests.

Treatment is chosen by your doctor and may include:

• Medicines to control heart rate or rhythm
• Anticoagulants to lower the risk of blood clots and stroke
• Procedures such as ablation, electrical cardioversion, or fitting a pacemaker or implantable cardioverter defibrillator
• Treating another condition or changing a medicine if that is causing AF

The CDC adds that medicine and lifestyle changes to manage risk factors are part of care.

When to see a doctor

See a doctor, not urgently, if you think you have AF symptoms, if palpitations keep happening or get worse, or if your treatment is not helping.

Call emergency services if you have a fast or irregular heartbeat along with chest pain, shortness of breath, sweating, feeling or being sick, fainting, dizziness or falling, a severe headache, weakness or numbness on one side of the face or body, blurred vision or loss of sight, or confusion or difficulty speaking. The NHS says not to drive yourself to hospital.

In an emergency, call your local emergency number (112 in India, 911 in the United States).