Heart arrhythmias and palpitations

Normally, the pumping action of your heart (your heartbeat) is controlled by your heart’s electrical system. In a healthy heart, regular electrical signals make the heart contract and relax in a steady rhythm of 60 to 100 beats per minute.

Sometimes the heart’s electrical system does not work properly, because of heart disease, certain medicines, or sometimes for no known reason. Changes in this electrical system can cause abnormal heart rhythms, also called arrhythmias.

Heart palpitations#

A palpitation is an awareness of your heart beating. It may feel like your heart is racing, thumping, fluttering, pounding or skipping beats. Almost everyone has palpitations at some time in their life.

Palpitations may have no obvious cause, but can be triggered by things such as:

• Physical activity
• Emotional stress
• Caffeine
• Nicotine
• Alcohol
• Stopping certain medicines
• Recreational drugs

An occasional palpitation that does not affect your general health is not usually something to worry about. See your doctor if you have more frequent or persistent palpitations, as these can sometimes be linked to a serious abnormal heart rhythm.

Types of abnormal heart rhythm#

There are many kinds of abnormal heart rhythm. Some cause your heart to skip or add a beat now and again, but usually have no effect on your health or your ability to lead a normal life. Others are more serious and can be life-threatening if left untreated.

Abnormal rhythms are usually grouped by their rate and pattern: a fast heartbeat (tachycardia), a slow heartbeat (bradycardia) or an irregular heartbeat.

Tachycardia#

Tachycardia is when your heart beats too fast, generally more than 100 beats per minute. Some forms are easily treated and not serious, while others can be life-threatening. The two main types are:

• Supraventricular tachycardia - a problem with the upper chambers of the heart. This is not usually life-threatening. A common type is atrial flutter.
• Ventricular tachycardia - this happens when the ventricles (the lower chambers) beat too fast, and it can be very dangerous.

If ventricular tachycardia becomes so severe that the ventricles can no longer pump effectively, it can lead to ventricular fibrillation. This life-threatening condition occurs when the electrical signals that should trigger your heartbeat behave erratically. It must be corrected immediately, otherwise it may cause low blood pressure, loss of consciousness and even death.

Bradycardia#

Bradycardia is when your heart beats too slowly, generally less than 60 beats per minute. It becomes serious when the heart beats so slowly that it cannot pump enough blood to meet your body’s needs. A slower heart rate may be normal for you, and some people who do a lot of exercise and are very fit have a slower rate. However, bradycardia can also be caused by heart disorders, such as sick sinus syndrome and heart block.

• Sick sinus syndrome occurs when the heart’s natural pacemaker (the sinus node) malfunctions and fires too slowly, telling the heart to beat slowly. It can also cause heartbeats that are too fast, or beats that alternate between slow and fast.
• Heart block is when there is a block or delay in the electrical signal travelling from the heart’s upper chambers (atria) to its lower chambers (ventricles). It often results from damage to the heart’s electrical pathways. Types include atrioventricular heart block and bundle branch block.

Other types of abnormal heart rhythm#

• Ectopic heartbeats occur when your heart misses a beat or adds an extra beat. They can arise from the atria or the ventricles.
• Long QT syndrome, Brugada syndrome and Wolff-Parkinson-White (WPW) syndrome are related to specific abnormalities in the heart’s electrical system. They can cause fast and irregular heartbeats and may lead to fainting.
• Paroxysmal arrhythmias start and stop suddenly. An episode can last for seconds, minutes, hours or up to a week.

Symptoms of an abnormal heart rhythm#

Occasional palpitations during periods of emotional or physical stress are normal and nothing to worry about. However, an irregular heartbeat can be a sign of an abnormal heart rhythm or another heart condition. Talk to your doctor if you feel your heart beating too fast, too slowly or irregularly.

Symptoms can include:

• Palpitations (a feeling of your heart racing, thumping, fluttering, pounding or skipping beats)
• Light-headedness or dizziness
• Shortness of breath
• Sweating
• Fainting
• Anxiety
• Chest pain
• Fatigue

Immediately call your local emergency number (for example 911 in the US and Canada, 112 across the EU and many countries, 999 in the UK, or 000 in Australia) and ask for an ambulance if, along with palpitations, you start to feel any of the following:

• Pain or discomfort (pressure, heaviness or tightness) in your chest, neck, arms, back or shoulders
• Nausea
• A cold sweat
• Dizziness or shortness of breath
• These feelings lasting for more than 10 minutes

Causes and triggers#

Some conditions can lead to an abnormal heart rhythm, including:

• Structural heart abnormalities, such as cardiomyopathy, heart valve disease or scarring from a previous heart attack
• A heart attack
• Congenital heart disease
• Coronary heart disease
• Diabetes
• Heart failure
• High blood pressure
• Obstructive sleep apnoea
• Thyroid problems

Common triggers of an abnormal heart rhythm include:

• Alcohol
• Caffeine
• Nicotine (in cigarettes or e-cigarettes)
• Another unrelated illness, such as a cold or flu
• Recreational drugs
• Some medicines (over-the-counter or prescription)
• Physical or emotional stress
• Tiredness

Talk to your doctor if you think a medicine is triggering an abnormal rhythm. Never stop taking a prescription medicine without talking to your doctor or pharmacist first.

In some people, certain types of exercise may trigger an abnormal heart rhythm. If you think this is happening to you, talk to your doctor. Physical activity is very important for your heart health and overall wellbeing, and should not be avoided without medical advice first.

Diagnosing an abnormal heart rhythm#

If you have any symptoms of an abnormal heart rhythm, including palpitations, see your doctor. Ways of diagnosing an abnormal rhythm include:

• A physical examination, including listening to the heart with a stethoscope
• Blood tests
• An electrocardiogram (ECG), which records a detailed snapshot of your heart rate and rhythm. You may have this while resting or exercising (for example, on a treadmill), or you may wear a portable ECG recorder for a longer period (for example, 24 hours)
• An echocardiogram (an ultrasound scan of the heart), which helps your doctor check the heart’s valves and see how strongly it pumps
• Electrophysiology studies, in which a catheter is guided to your heart while you are sedated to record its electrical activity and response to certain triggers
• A tilt test, to find out whether different body positions trigger the abnormal rhythm

Treatment#

Treatment for an abnormal rhythm depends on its cause and how much it is affecting your health and lifestyle. Not all abnormal rhythms are dangerous or life-threatening. Treatments include:

• Medicines, to stabilise the heart rhythm or to treat conditions causing the abnormal rhythm
• Electrical cardioversion, a mild electrical current that restores a normal heart rhythm. This is usually a planned procedure given under sedation
• Catheter ablation, in which a catheter with an electrode on the end is guided to your heart, where it gently disrupts or deactivates the area producing the abnormal electrical signals
• A pacemaker, a small electronic device that electrically stimulates the heart to maintain a regular rhythm
• An implantable cardioverter defibrillator, a device that monitors your heart rhythm and corrects it if it becomes dangerous
• Defibrillation, the use of a mild electrical current to reset your heart rhythm. This is usually given in an emergency
• Surgery, to remove or inactivate the malfunctioning area or areas of the heart

Living with an abnormal heart rhythm#

If you have been diagnosed with an abnormal heart rhythm, you may wonder how serious your condition is and what it means for the future. It is also normal to feel a range of emotions, such as fear, uncertainty, anxiety and low mood. If you are worried about how you are feeling, talk to your doctor and seek support from your loved ones.

To help manage your condition, you can:

• Identify your triggers
• Take your medicines as prescribed
• Make healthy lifestyle changes, including managing stress, quitting smoking, drinking less alcohol, following a heart-healthy eating pattern and staying active
• Manage your blood pressure and cholesterol levels
• Maintain a healthy body weight

Key points#

• The heart’s pumping action is controlled by its electrical system; changes in that system can cause abnormal heart rhythms, also called arrhythmias
• Palpitations may have no obvious cause but can be triggered by things such as stress, caffeine, nicotine, alcohol and some medicines
• Some abnormal rhythms are harmless, while others, such as ventricular fibrillation, must be corrected immediately or they can lead to loss of consciousness and death
• Bradycardia can be normal in very fit people, but it can also be caused by heart disorders such as sick sinus syndrome and heart block
• See your doctor if your heart beats too fast, too slowly or irregularly

Where to get help#