Atrial fibrillation 


Atrial flutter

Atrial flutter is a less common condition which shares the same symptoms, causes and risk of complications as atrial fibrillation. Around a third of people with atrial flutter also have atrial fibrillation.

The main difference between the two conditions is the abnormal heart rhythms, which have a more predictable pattern and rhythm than in atrial flutter.

Treatment for atrial flutter is also slightly different, as catheter ablation is considered the best treatment, whereas for atrial fibrillation medication is often tried first. You can read more detailed information on catheter ablation on the Arrhythmia Alliance website.

Atrial fibrillation is a heart condition that causes an irregular and often abnormally fast heart rate.

A normal heart rate should be between 60 and 100 beats a minute when you're resting, and is regular. You can measure your heart rate by feeling the pulse in your wrist or neck. In atrial fibrillation, the heart rate may be over 140 beats a minute, although it can be any speed. 

The main difference between a normal rhythm and atrial fibrillation is that you are unable to predict when the next heart beat will come along, as heart rate is irregular.

This may lead to a number of problems, including dizziness and shortness of breath. You may also be aware of a fast and irregular heartbeat (palpitations) and feel very tired.

Read more about the symptoms of atrial fibrillation.

Some people with atrial fibrillation have no symptoms and are completely unaware that their heart rate is not regular.

When to see your GP

Make an appointment to see your GP if:

  • you notice a sudden change in your heartbeat
  • your heart rate is consistently lower than 60 or above 100 - especially if you are experiencing other symptoms of atrial fibrillation

See your GP as soon as possible if you have chest pain.

What happens in atrial fibrillation?

When the heart beats normally, its muscular walls contract (tighten and squeeze) to force blood out and around the body. They then relax, so the heart can fill with blood again. This process is repeated every time the heart beats.

In atrial fibrillation, the upper chambers of the heart, called the atria, contract randomly and sometimes so fast that the heart muscle cannot relax properly between contractions. This reduces the heart's efficiency and performance.

Why it happens

Atrial fibrillation occurs when abnormal electrical impulses suddenly start firing in the atria. These impulses override the heart's natural pacemaker, which can no longer control the rhythm of the heart. This causes you to have a highly irregular pulse rate.

The cause is not fully understood, but it tends to occur in certain groups of people (see below) and may be triggered by certain situations, such as drinking excessive amounts of alcohol or smoking.

Read more about the causes of atrial fibrillation.

Atrial fibrillation may be defined in various ways, depending on the degree to which it affects you:

  • Paroxysmal atrial fibrillation - this comes and goes and usually stops within 48 hours without any treatment.
  • Persistent atrial fibrillation - this lasts for longer than seven days (or less when it is treated).
  • Longstanding persistent atrial fibrillation - this means you have had continuous atrial fibrillation for a year or longer.
  • Permanent atrial fibrillation - atrial fibrillation is present all the time and no more attempts to restore normal heart rhythm will be made.

Who is affected?

Atrial fibrillation is the most common heart rhythm disturbance and affects up to 800,000 people in the UK.

Atrial fibrillation can affect adults of any age. However, it affects more men than women and becomes more common the older you get. It affects about 10% of people over 75.

Atrial fibrillation is more likely to occur in people with other conditions, such as high blood pressure or atherosclerosis.

It's uncommon in younger people, but may be slightly more common in people with another heart condition, such as a heart valve problem.

Treating atrial fibrillation

Atrial fibrillation is generally not life threatening, but it can be uncomfortable and often needs treatment.

Treatment may involve: 

  • medication to prevent a stroke
  • medication to control the heart rate or rhythm
  • cardioversion, where the heart is given a controlled electric shock to restore normal rhythm
  • cather ablation, to prevent atrial fibrillation from occurring
  • having a pacemaker fitted to help your heart beat regularly

Read more detailed information about treatment for atrial fibrillation.

The main complication of atrial fibrillation is an increased risk of stroke.

Page last reviewed: 09/07/2013

Next review due: 09/07/2015


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The 5 comments posted are personal views. Any information they give has not been checked and may not be accurate.

LKLPKL said on 28 September 2014

In the past I have had the occasional palpitation, feels as though my heart has missed a beat. Just over a year ago I experienced a fluttery feeling in my chest on several occasions, felt like my heart was racing, but only lasted for about a minute or so. then one episode lasted for nearly half and hour, however I didn't experience any other symptoms, it just felt really weird. I sat down for a while and had a drink of water and waited for it to stop. I was frightened by this so went to see my GP . He sent me to the practice nurse who did a quick ECG. I was told everything looked fine and not to worry about it unless I became dizzy or breathless. Earlier this year my Mum found out during a routine examination that she has an Atrial Fibrillation and is now taking Warfarin. She has never had any symptoms. I mentioned to the cardiologist about my episodes of palpitations and she said I should go back to my GP and ask them to pursue it. I never did because they appeared to have subsided. However this past couple of weeks it has started happening again. Sometimes when I am at rest, sometimes when I am at work, and this past Saturday while at work it happened again and I also felt slightly dizzy, it lasted for about 5 minutes, and afterwards I had a slight headache for about half an hour then I felt fine. I really don't know what to do because I am sure if I go back to my GP they will just do another ECG which won't show anything unless I am having the palpitations at that time. Just wondered if anyone else has experienced same thing ?

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Burkhill1987 said on 27 February 2014

Hi Anneka8 I have had this procedure done before! Not for atrial fibrillation but atrial flutter. The radio ablation is the same it's just for af it takes a bit longer than for atrial flutter. What will happen is that you'll be taken to a catheter lab and placed on a bed with all different machines and wires blood pressure,heart rate monitor and all that. Then the anesthetist will give you a local or general anesthetic (you're choice) personally i would have general but it all depends on how you are with anesthetic.

Then he will make an incision in your leg where your groin is and open up a little hole (the incision CAN be uncomfortable) then he will but the catheter into your heart through the vein in your leg and he will make incisions inside your atrial to stop the extra impulses going through it. Then once he's happy with the ablation he will remove the catheter and you'll be place in recovery for half hour and then moved to a ward where you will have to lay down for maybe an hour just so the incision heals. Then you'll be ok to move around. You'll probably be let home the next day and will have to use anticoagulants to stop blood from clotting hope this helps

Ps I only used he in the explanation because my cardiologist was a man. You have nothing to worry bout it's a very simple procedure if your worried about anything you should always ask your cardiologist

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anneka8 said on 11 January 2014

A few weeks ago my heart went into AF and I had to go to hospital and have intravenous treatment to stabelise it, which worked, I have seen a specialist who has given me 3 options as apparently I am at high risk of Stroke with this I am 52 don't smoke or drink and never thought I would have this issue, one suggestion is beta blockers for now but a procedure called radio frequency Abollation which I don't know much about has anyone had this done and if so what was the outcome please, as I am really frightened at the moment and need to understand this.

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Hurren said on 12 January 2011

I have been told that I have atrial flutter and that this quite different from atrial fibrillation yet there is no mention of flutter on the page.

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Chritsino said on 10 January 2011

Artial Fibrillation is due to the irregularity of sinus node many impulses rise in atria causing missing of pulses. Cardiac rhythm disturbance characterized by uncoordinated, rapid atrial contractions of up to 350 or more impulses per minute Causes are hypertension, Coronary artery disease, heart Failure, Congenital heart disease.

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