Atrial fibrillation

What is atrial fibrillation?

A normal resting heart rate is between 60 and 100 regular beats per minute. If you have atrial fibrillation (AF), the heart can beat extremely fast – sometimes between 140-180 beats per minute – and have an irregular rhythm.

This kind of abnormal heart rhythm is called an arrhythmia.

AF happens when there’s a fault in the heart’s electrical system, causing its upper chambers (the atria) to beat unusually fast. This makes them quiver – known as atrial fibrillation – and leads to an irregular, sometimes quick, heartbeat or pulse.

Atrial fibrillation symptoms

Some people with AF have no obvious symptoms – they may not be aware that they have an irregular heart rate if they don’t have a fast heartbeat. In these cases, it’s often not discovered until a doctor examines a patient or tests for other conditions.

Symptoms of AF may include:

• Heart palpitations –feeling like your heart is beating fast or getting a pounding or fluttering sensation

• Fast heart rate – a heart rate that’s significantly higher than 100 beats per minute

• Breathlessness

• Feeling dizzy or lightheaded

• Chest pain

• Tiredness

Types of atrial fibrillation

You may experience atrial fibrillation constantly, or it might come and go. The types of AF are defined by how much you’re affected.

• Paroxysmal atrial fibrillation – Episodes come and go, usually lasting less than 48 hours and don’t require treatment

• Persistent atrial fibrillation – Each episode lasts longer than seven days without treatment but can return to normal with treatment

• Permanent atrial fibrillation – AF is present at all times, and the heart rate doesn’t return to normal

What causes atrial fibrillation?

Often, AF is connected to another medical condition, but not always. When there’s no link to another illness, it’s known as lone atrial fibrillation.
Common heart conditions linked to AF include:

• High blood pressure

• Heart valve disease

• Congenital heart disease

• Atherosclerosis

• Cardiomyopathy

• Pericarditis

Other conditions that can be associated with AF are:

• Overactive thyroid gland

• Pneumonia

• Asthma

• Lung cancer

• Diabetes

• Pulmonary embolism(PE)

• Chronic obstructive pulmonary disease (COPD)

When to see a doctor

Talk to a doctor immediately if:

• There is a sudden change in your heart rate

• You have chest pain

• Your heart rate is lower than 60 beats per minute or higher than 100 beats per minute

Atrial fibrillation diagnosis

The doctor will take your pulse to see if your heart rate is irregular or unusually fast. If they think you have AF, they’ll refer you for more tests - these may include:

• Electrocardiogram (ECG) – To record your heart's rhythm and electrical activity

• Echocardiogram – A heart scan that can help to identify other heart-related problems

• Chest x-ray – To look for lung problems that may be linked to AF

• Blood tests

Atrial fibrillation treatment

There are many treatment options for AF and you should be able to live life normally once you find the right treatment.

AF treatment aims to control the rate and rhythm of the heart. If there’s an underlying medical cause of AF, you’ll be treated for this first to see if it also helps your AF symptoms.

When there’s no underlying cause, treatment may include:

• Anti-arrhythmic drugs – These treat atrial fibrillation in two ways, firstly to control the heart rate and secondly to restore a regular heart rhythm. Anti-arrhythmic drugs include beta blockers and calcium channel blockers and the medication you’re prescribed will depend on the type of atrial fibrillation and whether you have any other medical conditions.

• Medication to reduce the risk of a stroke – Certain factors, like age and your medical history, can put you at greater risk of stroke if you have atrial fibrillation. You may be recommended medication like anticoagulants to help reduce this risk.

• Cardioversion – This electric shock treatment gives controlled electric shocks to the heart to try and regulate the heart’s rhythm.

• Catheter ablation – A quick procedure that uses catheters (soft, hollow tubes) and heat or extreme cold to create scar tissue on the area of your heart that’s causing the abnormal heart rhythm. This interrupts abnormal circuits in the heart and destroys the problematic areas of the heart muscle.

• Having a pacemaker fitted – A small device implanted in your chest to help your heart beat regularly.

Atrial fibrillation complications

People with AF have four to five times increased risk of stroke to people without AF. This is because when the atria in the upper chambers of the heart aren’t pumping properly with AF, there’s a risk of blood clots forming. If these get into the body’s general circulation, it can block the brain's arteries and lead to a stroke.

Persistent AF can also weaken the heart. In severe cases it may even lead to heart failure as your heart can’t pump blood around your body properly.