Palpitations 

We have selected the following expert medical opinion based on its clarity, reliability and accuracy. Credit: Source: website Patient UK, authored by Dr Colin Tidy (see below). Please refer to your own medical practitioner for a final perspective, assessment or evaluation.

Overview

Palpitations are the sensation of your heart beating and are common. Most cases are harmless. They usually only last for a short time and can be accompanied by other symptoms such as breathlessness, dizziness, chest tightness and a feeling of anxiety. Palpitations that are severe or don't settle quickly may need urgent medical attention. The most common causes are mentioned below.

Palpitations are rapid, thumping or fluttering feelings that people experience in their chest. They may be on the left-hand side or the middle of the chest. Normally we are not aware of our heart beating. The term 'palpitations' is used when we are aware of our heart beating. Some people say their heart feels like it's racing; others say their chest hurts, thumps or flutters. Usually this sensation is caused by a heart rate that is faster than usual for your age, gender and level of fitness. Occasionally, the feeling is due to an irregular heart rate.
 

What is the normal heartbeat and conducting system?

The heart is a muscle that pumps blood around the body. It has two upper chambers - the right atrium (RA) and the left atrium (LA) - and two lower chambers - the right ventricle (RV) and the left ventricle (LV).

The pumping movements of the upper and lower chambers of the heart are coordinated to ensure constant circulation of the blood through our bodies. When we need more oxygen to reach our cells - for example, when exercising - the heart beats faster to pump more blood to the lungs and cells.

The heart needs a small electrical current to pass through the heart in a very set pattern. This is called the heart's conduction system.

The sequence of each heartbeat is as follows:

The sinoatrial node (SA node) in the right atrium is a tiny in-built 'timer'. It fires off an electrical impulse at regular intervals (about 60-80 per minute when you rest and faster when you exercise). This controls your heart rate. Each impulse spreads across both atria. This causes them to contract and pump blood through one-way valves into the ventricles.

The electrical impulse gets to the atrioventricular node (AV node) at the lower right atrium. This acts like a 'junction box' and the impulse is delayed slightly. Most of the tissue between the atria and ventricles does not conduct the impulse. However, a thin band of conducting fibres called the atrioventricular bundle (AV bundle) acts like 'wires' and carries the impulse from the AV node to the ventricles.

The AV bundle splits into two - a right and a left branch. These then split into many tiny fibres (the Purkinje system) which conduct the electrical impulse throughout the ventricles.

This makes the ventricles contract and pump blood through one-way valves into large arteries:

• The artery going from the right ventricle (pulmonary artery) takes blood to the lungs.
• The artery going from the left ventricle (aorta) takes blood to the rest of the body.
• The heart then rests for a short time (diastole). Blood coming back to the heart from the large veins fills the atria during diastole:
• The veins coming into the left atria bring blood from the lungs (full of oxygen).
• The veins coming into the right atria bring blood from the body (needing oxygen).

What types of palpitations are there?

Palpitations can be caused by:

• An unusually rapid but regular heart rate; or
• An unusually slow heart rate; or
• Extra beats of the heart; or
• An abnormal heart rhythm; or
• A combination of the above.

The heart usually beats at around 70 beats per minute (bpm). The normal range for an adult can be anything from 40-100 bpm. Your normal resting rate depends on your age and level of fitness. Generally speaking, the fitter you are, the slower your pulse. Also, generally heart rate increases a little with age. Your normal heart rate may increase for several reasons.

An abnormal heart rhythm can cause palpitations. Your pulse will feel irregular because the heart will be beating in an uncoordinated way. An abnormal heart rhythm can result from abnormal electrical activity in the atria or ventricles. Those originating from the ventricle are less common and can be more dangerous than atrial ones.

Complications

What problems can cause palpitations?

This list does not include all the possible causes of palpitations but lists some of the more common causes, including:

• A fast but regular heartbeat (sinus tachycardia)
• There are many reasons why the heart rate can be faster than normal. Some of these are:
• Exercise: Your heart beats faster when you exercise; it then gradually slows to normal afterwards.
• Anxiety: This can be either normal worry, or excessive worry, such as in panic attacks or anxiety disorder.
• Caffeine: Drinking too much caffeine in coffee, tea, cola or drinks such as Red Bull® may cause your heart to beat faster, giving you palpitations.
• Alcohol.
• Certain medication: Some medication such as salbutamol, terbutaline, hyoscine and hydralazine, amongst others, can cause your heart to beat faster. Some over-the-counter cough and cold medicines can also do this.
• Other stimulant drugs: Some recreational drugs such as ecstasy, cannabis, cocaine and amphetamines can cause a fast heart rate.
• An overactive thyroid gland.
• Preganancy.
• Smoking: The nicotine in cigarettes can cause a faster heart rate.
• Having a high temperature (fever).
• A serious underlying abnormality of the heart is a rare cause of sinus tachycardia. Serious heart problems are more likely to cause prolonged runs of palpitations and often other problems such as breathlessness.

Treatment will depend on the underlying reason for the fast heart rate.

Abnormal heart rhythms (arrhythmias)

These include:

• Atrial fibrillation (AF). 
• Supraventricular tachycardia (SVT).
• Ventricular arrhythmias.

Ventricular arrhythmias

These are much less common and potentially more dangerous than atrial arrhythmias such as AF and SVT. Diagnosis is made by a heart tracing (electrocardiogram, or ECG) and referral to a heart specialist (cardiologist) for expert advice will be necessary.

Diagnosis

What investigations might be advised?

You are likely to be asked about your intake of the substances mentioned above and the circumstances in which the palpitations occur. Your doctor will take your pulse and blood pressure, listen to your heart and order further tests as appropriate.

Initial investigations will include:

• Blood tests to check for anaemia and an overactive thyroid gland.
• Electrocardiogram (ECG) to record the electrical activity of your heart to check whether the heart rate is regular, and of normal rate. It also looks for underlying or previous heart disease.
• Ambulatory ECG: this is an ECG that monitors your heart as you carry on your normal life over 24 or 48 hours. You will be asked to make a note of when you get the palpitations. The reading will then show what your heart was doing when you felt the palpitations.

Further investigations of the heart may also be necessary:

• In some cases, you may need an ultrasound scan of the heart (an echocardiogram, or 'echo').
• In other cases, you may need a test of your heart while you exercise.
• Electrophysiology tests may also be used. Small wires (electrodes) are inserted into your heart via one of your veins. These wires measure the electrical signals in your heart and can determine where any abnormal electrical signals are coming from.

All these tests are to make sure there is no abnormality in your heart causing the palpitations. However, in many cases, palpitations are NOT caused by any problem with your heart.

Treatment 

What is the treatment for palpitations?

Treatment will depend on the likely cause of your palpitations. If, for example, your palpitations are caused by drinking too much caffeine, you will be advised to cut down how much caffeine you drink. If your palpitations are caused by anxiety, your GP will discuss ways of managing this.

Some cases of palpitations are managed by a GP; other cases may be referred to a heart specialist (cardiologist). In either case, the treatment you will be given depends on the cause that has been found.

What should I do if I have palpitations?

Occasionally, palpitations can be serious.

In the following situations, you should call an ambulance:

• If you have palpitations that do not go away quickly (within a few minutes).
• If you have any chest pain with palpitations.
• If you have severe breathlessness with palpitations.
• If you pass out or feel as if you are going to pass out or feel dizzy.
• If you have palpitations and have had heart problems in the past.
• If you have palpitations which began as you were exercising.

If the palpitations do not make you feel unwell, and settle on their own, you should see your GP. Keep a diary of when they happen and how long they last, as this information will help your GP.

If you have an episode of palpitations it can be useful to check your pulse. In particular it may be useful for your doctor to know how fast your pulse was during the episode. That is, how many beats per minute; also, if your pulse felt regular or irregular. This information can help identify the cause of the palpitations.

About the author

Dr Colin Tidy

MBBS, MRCGP, MRCP, DCH

Dr Colin Tidy qualified as a doctor in 1983 and he has been writing for Patient since 2004. Dr Tidy has 25 years’ experience as a General Practitioner. He now works as a GP in Oxfordshire, with a special interest in teaching doctors and nurses, as well as medical students.  In addition to writing many leaflets and articles for Patient, Dr Tidy has also contributed to medical journals and written a number of educational articles for General Practitioner magazines.

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