What is palpitation?
Palpitation is a word used to describe the feeling
you get when you are aware of your heartbeat. The
heart may be beating at a normal rate, quickly,
slowly or irregularly, or it may be missing beats.
Most palpitations are quite harmless, although they
can be unpleasant and distressing. Everyone has
them at some time, including people without heart
disease. There are many causes of palpitation,
including fear, anger, physical activity, fever, stomach
upsets or drinking alcohol.
However, some palpitations are caused by disease.
These palpitations may feel particularly unpleasant
as the heartbeat may be very fast, very slow or very
irregular. Bouts of palpitation may last for seconds,
minutes or hours. Some people have very rare
episodes,while others have palpitation every day.
Attacks may happen suddenly and unexpectedly,
but a few may be triggered by things such as
anxiety or exercise. Palpitations that cause
symptoms such as sweating, breathlessness,
faintness, chest pain or dizziness,will usually need
further investigation.
Normal heart rhythms
The heart is a muscular pump which circulates
blood through the body and lungs. It has four
chambers – two upper ones called the right and
left atria, and two lower ones called the right and
left ventricles.
The heart’s pumping action is controlled by tiny
electrical impulses produced by a part of the right
atrium called the ‘sinus node’. This is sometimes
called the heart’s ’natural pacemaker’. The
rhythmical impulses produced by the sinus node
make the atria contract and push blood into the
ventricles. The electrical impulses travel to the
ventricles through the atrio-ventricular node (or
‘AV node’). This acts like a junction box and is
sometimes called the ‘AV junction’. The impulse is
delayed a little before it enters the ventricles
through fibres which act like ‘wires’ (the Purkinje
system). When the impulse reaches the ventricles
they both contract, pushing the blood out of the
heart to the lungs and the rest of the body. In a
normal heart rhythm, each impulse from the heart’s
pacemaker makes the atria and the ventricles
contract regularly and in the correct order.
Normal electrical signals in the heart
pacemaker
(sinus node)
The pacemaker
produces between
50 and 100 electrical
impulses a minute
electrical
impulses
right atrium
AV node (AV junction)
chemical
impulses
nervous
impulses
hormonal
impulses
right
ventricle
(pumping chamber)
left
ventricle
(pumping
chamber)
left
atrium
aorta
Purkinje system
hormonal
impulses
chemical
impulses
nervous
impulses
pacemaker
(sinus node)
The pacemaker
produces between 60
and 100 electrical
impulses a minute
while you are resting.
right atrium
AV node (AV junction)
The electrical impulses
travel from the atria to
the ventricles through
the AV node.
Purkinje system
electrical
impulses
left
atrium
left ventricle
(pumping
chamber)
right
ventricle
(pumping
chamber)
While you are resting, your heart’s pacemaker
produces between 60 and 100 impulses a minute.
It is the pumping of blood that produces your
pulse,which you can feel, for example, at the artery
in your wrist. Doctors can measure the rate and
rhythm of your heart by taking your pulse.
Sometimes, the heart will beat faster or more
slowly, depending on your state of health and
whether you have been active or resting. When the
heart is beating fast, this is called ‘sinus tachycardia’.
When it is beating slowly, it is called ‘sinus
bradycardia’. These are normal heart rhythms and
do not mean that there is anything wrong with
your heart.
A normal but fast rhythm (sinus tachycardia)
Being physically active creates certain reactions in
the nervous system and in the body’s chemicals
which make the pacemaker speed up. When the
heart rate produced by the sinus node goes above
100 beats a minute, the rhythm is called ‘sinus
tachycardia’. Tachy means fast and cardia means
heart. The chemicals involved are called
‘catecholamines’, one of which is adrenaline.
Adrenaline is also released when we are frightened
– it prepares our body for action. The heart beats
quickly and powerfully to pump out more blood, to
make you ready for ‘fight or flight’.
Your heart rate may also be increased if you have
an overactive thyroid gland, a fever or anaemia, or if
you are pregnant.
A normal but slow rhythm (sinus bradycardia)
When the sinus node slows the heart rate to below
60 beats a minute, the rhythm is called ‘sinus
bradycardia’. Brady means slow and cardia means
heart. Many athletes have sinus bradycardia. Also,
when you are feeling sick it is normal for your heart
to slow down. If the heart slows down too much, it
may make you faint.
“My heart sometimes seems to have an extra beat.”
Extra heartbeats – called ‘ectopic beats’ – are very
common. They may be extra beats from upper
chambers of the heart (the atria) or they may be
from the lower chambers of the heart (the
ventricles). Most people have at least one ectopic
beat every 24 hours but they are more common in
people who a have a heart condition.
Most ectopic beats go unnoticed. If you do notice
an ectopic beat, it may feel like a thud in the chest,
a brief irregular heart rhythm, or a missed
heartbeat. Sometimes, you may notice an ectopic
beat when you are in bed lying in a position where
you can ‘hear’ your heart rhythm. Tiredness or
alcohol can make you more aware of these extra
beats. It is possible that coffee and tea may
occasionally trigger ectopic beats.
Ectopic beats are not dangerous and do not
damage your heart.
Fast, regular heartbeats
If you feel that your heart is beating too fast, but
still regularly, this can be:
• normal sinus tachycardia (see page 11)
• supraventricular tachycardia (see below), or
• ventricular tachycardia (see page 13).
Supraventricular tachycardia (also known as SVT,
paroxysmal SVT or PSVT)
Supraventricular tachycardia is a disturbance of the
heart rhythm caused by rapid electrical activity in
the upper parts of the heart (the atria). In these
attacks, the heart beats very fast, usually at a rate of
between 140 and 240 beats a minute.
Symptoms may be uncomfortable but they are not
usually harmful. The most common symptom is
palpitation, but there may also be breathlessness,
dizziness or, very occasionally, fainting. Sometimes
the SVT rhythm comes and goes. This is called
paroxysmal SVT. Attacks usually start at a young
age, may happen over many years, and tend to
reduce as you get older. Some people find that
certain things can trigger an attack, such as an
emotional upset, or anxiety. Drinking large
amounts of coffee or alcohol, or heavy
Palpitation l 11
12 l British Heart Foundation
cigarette-smoking, can also trigger an episode
of SVT.
An attack may last from a few seconds or minutes
to several hours. Attacks can often be stopped
by a technique called the ‘Valsalva manoeuvre’.
This involves taking a breath in and then ‘straining
out’,with the airway closed at the back of the
throat. Or, you could try swallowing something
cold – for example, some ice cream or a small
ice cube.
You may be able to prevent the palpitations by
avoiding the situations or the things that seem to
trigger them. Or, your doctor may be able to
prescribe medicines to help (see page 23). If the
attacks are troublesome, you may need to have
some tests done. These will include an ECG
(electrocardiogram) and perhaps a 24-hour ECG
recording or a patient-activated recording. If these
do not identify the problem, you may need to have
a small recording device implanted or an
electrophysiological study.
