Atrial Fibrillation/Flutter

What are atrial fibrillation and atrial flutter?

Atrial fibrillation (AF) and atrial flutter are both abnormal heart rhythms (arrhythmias) caused by a problem with the electrical signals in the atria, the upper chambers of your heart.

In AF, the atria beat too quickly in an irregular way. In atrial flutter, they beat too quickly but in a regular, steady pattern. Both can increase your risk of stroke, so getting the right diagnosis and treatment matters for either condition.

What are the symptoms of AF and atrial flutter?

The two conditions often cause similar symptoms, which can include:

• palpitations (a pounding, racing, fluttering or skipping sensation in your chest)
• tiredness or fatigue
• shortness of breath
• dizziness or feeling light-headed
• tightness in your chest
• feeling faint or fainting.

With AF, your pulse feels irregular and your resting heart rate may be faster than 100 beats per minute; you might also find exercise harder than usual.

With atrial flutter, your heartbeat is fast but stays steady, and can be constant or come and go. Many people with either condition have no symptoms at all, and are only diagnosed during a check-up or tests for something else.

AF symptoms may start and stop on their own (paroxysmal), stop once treated (persistent), or become ongoing over time (permanent).

It's also common to have both conditions: roughly 4 in 5 people with atrial flutter also have AF, and around 1 in 5 people with AF also have atrial flutter, though other estimates put the overlap with flutter closer to 4 in 10. If you have both, you may notice periods of flutter followed by periods of AF.

What causes AF and atrial flutter, and who's at risk?

Both conditions come from a problem with the heart's electrical system, though the underlying causes and risk factors overlap considerably.

Atrial fibrillation

You may be more likely to develop AF if you:

• are aged 55 or older, or are male
• are living with obesity or are overweight, or you smoke
• take certain medicines, such as levothyroxine, lithium, or some asthma medicines like salbutamol
• do endurance sports such as long-distance running, cycling or skiing.

AF can also be caused or triggered by another condition, including high blood pressure, heart failure, heart valve problems, Wolff-Parkinson-White syndrome, a previous heart attack, chronic kidney disease, an overactive thyroid, diabetes or sleep apnoea.

Atrial flutter

Atrial flutter is more common over the age of 50, and risk increases with age. It's often linked to an underlying heart or general health condition, such as:

• previous heart surgery, a heart attack or coronary heart disease
• heart valve disease or congenital heart disease
• high blood pressure or heart failure
• an overactive thyroid, chronic lung disease or diabetes.

More rarely, it's linked to cardiomyopathy (disease of the heart muscle) or inflammation of the heart. Alcohol and stimulants, including diet pills, cold medicines and caffeine, can also contribute to symptoms. Sometimes no cause is found for either condition.

AF is far more common than atrial flutter: AF affects around 1 in 45 people in the UK, while atrial flutter affects around 1 in 1,000.

Are there different types of AF and atrial flutter?

Beyond the core difference (irregular rhythm in AF, regular but fast rhythm in flutter), each condition has its own sub-types.

AF sub-types

• Paroxysmal AF: comes and goes on its own
• Persistent AF: needs treatment to stop it
• Permanent AF: ongoing.

Atrial flutter sub-types

• Typical atrial flutter: the more common form, arising from the right side of the heart, which tends to respond well to treatment
• Atypical atrial flutter: usually linked to scarring on the left side of the heart from previous surgery or disease, which can be more difficult to treat.

How are AF and atrial flutter diagnosed?

Both conditions are diagnosed using an electrocardiogram (ECG), which records the heart's electrical activity, alongside a physical examination and questions about your symptoms and family history.

Since AF or flutter can come and go, you may need more than one ECG, a 24-hour (Holter) monitor, or a small device called an implantable loop recorder fitted under the skin to catch the abnormal rhythm over a longer period.

You'll usually also have an echocardiogram (an ultrasound scan of the heart) to check its structure and function, and blood tests to look for underlying causes such as anaemia, kidney problems or an overactive thyroid. A chest X-ray may also be used to rule out a lung problem contributing to your symptoms.

How are AF and atrial flutter treated?

Treatment for both conditions can involve:

• medicines to control your heart rate or rhythm, such as beta blockers, calcium channel blockers or other anti-arrhythmic medicines
• blood-thinning medicines (anticoagulants), such as direct oral anticoagulants (DOACs) or warfarin, to lower your risk of stroke
• cardioversion, which uses medicine or a controlled electric shock to reset your heart's rhythm
• catheter ablation, a minimally invasive procedure using heat or extreme cold to destroy the small area of heart tissue causing the abnormal rhythm, usually done under local anaesthetic
• a pacemaker or implantable cardioverter defibrillator (ICD), if your heart rate remains difficult to control.

There's an important difference in how the two conditions are usually approached: medicine is often tried first for AF, whereas catheter ablation is generally considered the best treatment for atrial flutter.

For typical atrial flutter, ablation cures around 9 in 10 people; for atypical atrial flutter, it's successful in around 6 to 7 in 10 people, since further scarring can sometimes develop later.

Medication alone controls atrial flutter in only around 2 to 3 in 10 people, which is part of why ablation is often preferred where suitable.

If another condition, or a medicine you're taking, is found to be causing your AF, treating that condition or changing the medicine can sometimes improve your symptoms directly.

Things you can do yourself

• Try to avoid personal triggers such as caffeine, alcohol, spicy food, stress, dehydration and lack of sleep
• Aim for regular, moderate exercise (guidance varies, but roughly 150 minutes a week, or short sessions most days, is a reasonable general aim); avoid very intense exercise, which can itself trigger symptoms, and check with your doctor about what's right for you
• Keep to a healthy weight and eat a balanced diet
• Don't smoke and keep alcohol within recommended limits.

When should you see a doctor?

See a GP if you think you have symptoms of AF or atrial flutter, if palpitations keep happening or are getting worse, or if you've been diagnosed and your treatment isn't controlling your symptoms.

Call 999 if you currently have a fast or irregular heartbeat together with any of the following:

• chest pain, shortness of breath, sweating or feeling or being sick
• fainting, feeling dizzy or falling over
• a severe headache
• weakness or numbness down one side of your face or body
• blurred vision or loss of sight
• confusion or difficulty speaking.

The last four signs in particular can indicate a stroke, which both AF and atrial flutter increase the risk of. Don't drive yourself to A&E if you have any of these symptoms.