An arrhythmia, or abnormal heart rhythm, usually means your heart is beating too fast, too slow or irregularly.
What is an arrhythmia?
An arrhythmia is an abnormal heart rhythm. Your heart is controlled by a conduction system which sends out electrical impulses. This causes a heartbeat.
Arrhythmias are caused by a problem in this conduction system, which can make your heart beat too slowly, too quickly, or in an irregular way.
There are different types of arrhythmia, the most common are:
- Atrial fibrillation is the most common irregular, often fast heart rhythm.
- Supraventricular tachycardia (SVT) is a very fast heart rhythm. There are different types of SVT. Most are due to electrical impulses not travelling normally from the top chambers of the heart to the bottom chambers of the heart
- Atrial flutter is usually a fast heart rhythm where the top chambers of the heart contract at a very fast rate compared to the lower chambers. This can cause the top chambers to beat extremely fast, sometimes up to 300 beats per minute (bpm)
- Tachybrady syndrome (sick sinus syndrome) causes periods of very fast or slow heart beats
- Heart blocks are caused by a delay or blockage in the conduction system between the top and bottom chambers of the heart which can cause a slow heart rate.
Is your heart rate fast or slow?
Sinus tachycardia is when your heart beats in a regular way and faster than 100 bpmSinus bradycardias is when your heart beats in a regular way and 60 bpm or belowIf you have sinus tachycardia or sinus bradycardia it doesn’t mean there's something wrong with your heart and you might not need treatment. Sometimes it can be due to an underlying condition which you may need treatment for, so your doctor might want to send you for further tests to
find out
more.
What are the symptoms of an arrhythmia?
The symptoms you have depend on what type of arrhythmia you have. The most common symptoms include:
- palpitations (a thumping or fluttering sensation in your chest)
- dizziness
- feeling as if you may ‘black out’
- breathlessness
- chest discomfort
- feeling tired.
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When should I see my GP?
You should speak to your GP about your symptoms if:
- your palpitations last a long time, don't improve or get worse
- you have a history of heart problems
- you're concerned about the palpitations.
You should dial 999 for an ambulance if:
- along with palpitations, you start to feel short of breath, have chest pain or feel faint or dizzy.
What causes an arrhythmia?
Some underlying conditions which could cause an arrhythmia are:
- a heart attack
- heart failure
- cardiomyopathy
- coronary heart disease.
Some abnormal heart rhythms can be caused by inherited conditions, such as Long QT syndrome, Brugada syndrome, CPVT and PCCD.
If this is the case for you, your doctor will talk to you about having family members tested. Although this can be scary, it can help them know if they need treatment now or in the future.
Other common triggers of an arrhythmia include:
- viral illnesses
- recreational drugs
- alcohol
- smoking
- caffeine
- medications (over-the-counter and prescribed).
How is an arrhythmia diagnosed?
Your GP might refer you for tests including:
- an ECG
- an echocardiogram
- an electrophysiological (EP) study.
An ECG may include different tests such as a 24hr ECG, exercise ECG, and an implantable loop recorder. Information on what these tests are and what to expect can be found above on our ECG page.
How is an arrhythmia treated?
Your treatment will depend on your type of arrhythmia. Common treatments include:
- medication
- cardioversion
- catheter ablation
- inserting an implantable cardioverter defibrillator (ICD) or pacemaker.
Living with an arrhythmia
Most arrhythmias are manageable. This means that with the right treatment you can carry on living as you were before you were diagnosed.
Living with an abnormal heart rhythm can be emotionally challenging for you and your family. It's important to manage anxiety and stress and get support from your GP or loved ones if needed.
You might have to think about practical matters like driving, going on holiday and returning to work after being diagnosed with an arrhythmia.
If your ability to drive is affected, you must let your insurance company and the DVLA know. Your GP can advise on whether you need to do this.
If your job has an occupational health department, talk to them if you think your job role might have to be altered to better suit you.
- Read about Jim, who has atrial fibrillation.
Page last reviewed: October 2019 Next review due: October 2022Heart Helpline & other support: