5.NOV.2018 5 MIN READ | 5 MIN READ

An arrhythmia (irregular heartbeat) can occur in a healthy heart, but it can also be a warning sign for heart disease.

Last updated on 30 April 2021

Arrhythmia can be scary, and it’s important to know exactly what they mean. If you feel like there is something wrong with your heartbeat, or if you experience an arrhythmia that seems serious, unexpected, or accompanied by giddiness or chest pains, call emergency services or visit the A&E department.

Otherwise, read on for everything you need to know about irregular heartbeats.

What is an arrhythmia?

All about Arrhythmias - Arrhythmia
Usually, your heart beats at a regular rhythm, controlled by electrical activity in your body. The sinus node in your heart monitors how much blood your body needs, and sends electrical impulses that cause the chambers of your heart to contract at the correct pace for your body’s needs. Most people have a resting heart rate of 60 to 100 beats per minute, which speeds up during exercise or stressful situations. That’s completely normal. An arrhythmia is a change in this rhythm, when your heart beats too fast, too slow or at an irregular pace.

What are the different types of arrhythmia?

Arrhythmia are either ventricular (starting in the lower ventricles of the heart) or supraventricular (starting outside or above the ventricles, usually in the atria, the upper chambers of the heart). Common types of arrhythmia include:

Premature atrial contractions

Also known as PACs or APCs, these are extra beats in the heart’s upper chambers.

Premature ventricular contractions

Also known as PVCs, these are very common, and are ‘skipped’ heartbeats caused by the ventricles contracting too soon.

Supraventricular tachycardia (SVT)

Also known as paroxysmal supraventricular tachycardia (PSVT), where paroxysmal means occasional, this is a rapid heartbeat of 150 – 250 beats per minute, caused by electrical impulses in the atria.

Ventricular tachycardia

Known also as V-tach, this is a rapid heart rate starting from the lower heart, where the heart is unable to fill up with enough blood.

Atrial fibrillation

This is a fast, irregular heart rhythm where the muscles or fibres in your heart twitch and contract.

Ventricular fibrillation

This is a medical emergency where the heart’s lower chambers can’t contract to pump blood.

Atrial flutter

This is similar to atrial fibrillation, but more regular. The misfired electrical signals causing an irregular heartbeat and atrial flutter often lead to atrial fibrillation.

Accessory pathway tachycardia

This is a rapid heart rate due to an extra pathway between your heart’s chambers.


This is a slow heart rhythm usually caused by issues with your body’s electrical system.

Heart block

This is a problem with the speed of the impulses being sent through your heart, and in some cases a block of the impulses altogether, causing irregular heartbeats.

Symptoms of an arrhythmia

All about Arrhythmias - Symptoms
Depending on the type of arrhythmia, you might experience the following symptoms:

  • Heart palpitations, which feel like fluttering, skipped or extra beats
  • A pounding sensation in the chest or rapid heartbeat
  • Chest pain
  • Tightness in your chest
  • Shortness of breath
  • Fainting
  • Fatigue or a feeling of weakness
  • Dizziness or light-headedness
  • In severe cases, collapse and sudden heart attack

Causes of arrhythmia

Arrhythmia can be caused by structural issues with your heart, or congenital heart defects. These include an ongoing heart attack, the scarring of heart tissue from a prior heart attack or blocked arteries in your heart.

Arrhythmia may also signal heart disease. You might be suffering from some of the previously mentioned electrical disorders, such as atrial fibrillation or heart block, alone or alongside other serious heart conditions.

Some patients suffer from something known as long QT syndrome, an electrical disorder that is often inherited, and can trigger sudden and severe arrhythmia.

In other cases, it may be due to sick sinus syndrome, a group of symptoms that demonstrate the sinus node in your heart is not functioning correctly.

In some instances, arrhythmias can also be caused by problems outside of the heart, such as:

Other causes of an arrhythmia are stress or anxiety, smoking, high alcohol or caffeine intake, and certain medications, supplements and other stimulants like illegal drugs.

Most people will experience the sensation of a missed heartbeat or a random extra heartbeat at some point without explanation, and without any real risk to their health. However, if this happens to you often, for an extended period of time, or in conjunction with other symptoms, there may be an underlying issue.

Diagnosis of arrhythmia

All about Arrhythmias - Diagnosis
It is vital to see a doctor if you are suffering from arrhythmia regularly. Your doctor will perform tests to find out why your heart is not performing as it should. You might undergo:


This is a type of ultrasound to look at the structure of your heart.


Also known as an EKG or ECG, this test records any electrical activity occurring in your heart.

Stress test

Sometimes doctors will ask you to walk or run on a treadmill or exert yourself in some way while monitoring your heart rate.

At-home monitoring

Doctors may have you wear a heart monitor for a period of time to record how your heart performs day-to-day.

Cardiac catheterisation

This is the insertion of a catheter to inject dye into your heart, which is then viewed on an ultrasound.

It is important to remember that if you are suffering from an arrhythmia that seems severe or unexpected, or accompanied by dizziness or chest pains, you should not wait to visit a doctor. Instead, call emergency services or visit the A&E department.

Treatment for arrhythmia

The treatment your doctor prescribes for your arrhythmia will be specific to you and your condition. You may only require medication to control your symptoms, but in some cases more intervention may be necessary.

Electrical cardioversion

Doctors might perform electrical cardioversion, which is an electrical shock to the chest wall to rest your heart rhythm.


If a more long-term solution is required, you might have a pacemaker fitted, which is a small device that sends electrical impulses to the heart to keep it regular.

implantable cardioverter defibrillator

In extreme cases, you may require an implantable cardioverter defibrillator, which tracks your heart rate and delivers an electric shock to restore the heart’s rhythm when it beats too fast, too slow, or unevenly.

Heart surgery

Finally, doctors might decide that heart surgery is the best option to resolve your symptoms, but this is usually a last resort.

Keeping a healthy heart

All about Arrhythmias - Healthy heart
It is important for everyone to keep their heart as healthy as possible, even if they are not experiencing heart problems. Getting plenty of moderate exercise, cutting out cigarettes, maintaining a healthy weight and eating a fresh balanced diet are all easy ways to keep your heart in top condition. Try to eat plenty of heart-healthy foods like whole grains, fruit and vegetables, legumes like black beans or chickpeas, and lean proteins. Avoid processed food or food high in trans fats. Looking after yourself will give you and your heart the best chance of preventing arrhythmia and heart disease.


Article reviewed by Dr Hsu Li Fern, cardiologist at Mount Elizabeth Novena Hospital


About Arrhythmias. (2016, September 30). Retrieved October 13, 2018 from https://www.heart.org/en/health-topics/arrhythmia/about-arrhythmia

Categories of Arrhythmias. (n.d.). Retrieved October 13, 2018, from https://www.texasheart.org/heart-health/heart-information-center/topics/categories-of-arrhythmias/

Delicious Foods That Are Heart Healthy. (n.d.). Retrieved October 13, 2018 from https://www.webmd.com/cholesterol-management/guide/heart-healthy-diet#1

Heart Diseases and Disorders. (n.d.). Retrieved October 13, 2018 from https://www.hrsonline.org/Patient-Resources/Heart-Diseases-Disorders

Other Heart Rhythm Disorders. (2016, December 21). Retrieved October 13, 2018 from http://www.heart.org/HEARTORG/Conditions/Arrhythmia/AboutArrhythmia/Other-Rhythm-Disorders_UCM_302045_Article.jsp#.W8EwLRMzYWo

Steinbaum, S. (2017, August 24) What Are Heart Rhythm Disorders (Arrhythmias)? Retrieved October 13, 2018, from https://www.webmd.com/heart-disease/atrial-fibrillation/arrhythmia#3

Steinbaum, S. (2017, July 27) When Your Heart Rhythm Isn’t Normal. Retrieved October 13, 2018, from https://www.webmd.com/heart-disease/atrial-fibrillation/heart-disease-abnormal-heart-rhythm#4

Heart Arrhythmia. (2020, August 09) Retrieved March 17, 2021, from https://www.mayoclinic.org/diseases-conditions/heart-arrhythmia/symptoms-causes/syc-20350668

Hsu Li Fern
Mount Elizabeth Hospital

Dr Hsu Li Fern is a cardiologist and electrophysiologist at Mount Elizabeth Novena Hospital, Singapore.