What is atrial fibrillation, what causes an irregular heartbeat and is it different to atrial flutter?

ATRIAL fibrillation is the most common heart rhythm condition in the UK, affecting around 1.6 million people.

People with the condition have irregular heartbeats that are often very fast.

Recent research claims that sufferers are too readily being taken off medication, with around 130,000 high-risk patients not receiving the drugs they need.

The study warned that the number of people whose condition has been officially designated as “resolved” has increased substantially in the last 18 years.

What is atrial fibrillation and what are the symptoms?

A normal heart rate should be regular and between 60 and 100 beats a minute when you're resting.

But when you have atrial fibrillation, it becomes irregular and can reach considerably higher than 100 beats per minute.

Atrial fibrillation can sometimes not cause any noticeable symptoms, and someone with an irregular or quickened heart rate may not realise.

But more obvious symptoms can include dizziness, shortness of breath and tiredness.

Sufferers may also notice heart palpitations for a few seconds or minutes, where your heart feels like it's fluttering, bounding or beating irregularly.

Different types of atrial fibrillation include:

• Paroxysmal atrial fibrillation – episodes come and go, and usually stop within 48 hours without any treatment
• Persistent atrial fibrillation – each episode lasts for longer than 7 days (or less when it's treated)
• Long-standing persistent atrial fibrillation – where you have had continuous atrial fibrillation for a year or longer
• Permanent atrial fibrillation – where atrial fibrillation is present all the time

What causes an irregular heartbeat and who is most at risk?

For your heart to beat normally, its muscular walls must contract to 'squeeze' blood out and around the body.

The walls then relax, allowing the heart to fill back up with blood.

This is what happens every time your heart beats.

But when a patient has atrial fibrillation, the heart's atria (upper chambers) contract sporadically, sometimes too fast for the heart muscle to relax properly between contractions.

This happens because of abnormal electrical impulses in the atria.

These impulses throw off the heart's natural pacemaker, which leads to a higher pulse.

The exact cause of these abnormal electrical impulses is not known, but older people are more commonly affected (about 7 in 100 people over 65) and is more common in men than women.

Drinking too much alcohol or smoking could increase your risk of developing atrial fibrillation.

Is an atrial flutter different to atrial fibrillation?

While both conditions involve the heart's electrical activity, an atrial flutter is different to and less common than atrial fibrillation.

But the two are often linked: around a third of people who have atrial flutter also have atrial fibrillation.

With atrial flutter, the atria beat regularly but faster than normal, whereas the atria beat irregularly in atrial fibrillation.

The symptoms and possible causes of the two conditions are very similar.

How is an irregular heartbeat treated?

Both atrial flutter and atrial fibrillation carry increased risk of stroke in patients.

Medication to prevent a stroke, such as an anticoagulant, or to control the heart's rhythm can be prescribed.

Cardioversion, where the heart is given a controlled electric shock to restore normal rhythm, is another treatment option.

For atrial flutter, the best treatment option is usually considered to be a catheter ablation.

This is a procedure, conducted under local anaesthetic, where radiofrequency energy is used to destroy the area in your heart that's causing the abnormal rhythm.

A pacemaker may need to be fitted to help the heart keep a regular beat.