What causes sudden
death in young adults and children?
A sudden death in a young
person can be caused by:
cardiomyopathy, congenital heart disease, myocarditis, genetic
connective tissue disorders, mitral valve prolapse or conduction
We explain these below.
Heart disease is the most
common cause of an unexpected sudden death in all age
groups. In people aged 30 or over, the heart disease is usually due to
'furring' or 'blockages' of the blood vessels that
supply the heart, i.e. coronary artery disease. But
in younger people and in children the cause is much more often something
other than coronary artery disease. The main causes are listed below.
Some of these are inherited conditions. Some are detected
easily while the person is alive, while others may
go unnoticed until a tragic sudden death occurs.
These are abnormalities of the heart muscle and are usually inheritable.
cardiomyopathy (HCM) The walls of the heart
become abnormally thick without any other cause being identifiable.
Even if there is not any thickening, the arrangement of the heart's
muscle cells (myocytes) are disorganised and disrupted.
right ventricular cardiomyopathy (ARVC) This
condition causes the heart's muscle to become thin, because of an
abnormal amount of fat and scar tissue in its wall. It affects mainly
the right side of the heart.
cardiomyopathy (DCM) The left and right
sides of the heart become enlarged and pump less efficiently,
sometimes progressing to heart failure when the heart cannot meet the
This group includes abnormalities of the structure of the heart which have
been present since birth. Some of them may be
inherited conditions. They include:
more complex disease Abnormality of the
heart's valves that can be associated with other
abnormalities of the heart's structures such as
'a hole in the heart' (for example, Fallot's Tetralogy).
coronary arteries When there is an abnormal
arrangement of the arteries that supply blood to
the heart muscle.
Myocarditis is inflammation of the heart's muscle. It is usually due to a
viral infection although it can be a complication of
other medical conditions or exposure to drugs. It is
Genetic connective tissue
These are inheritable conditions affecting the
structures that give support, strength and
elasticity to the walls of the major blood vessels and, to a lesser
extent, the heart muscle - for example Marfan's
Syndrome and Ehler-Danlos. These can cause sudden
death by arrhythmias or due to the sudden rupture of a major blood vessel
such as the aorta (the major blood vessel that leaves the left side of the
heart and supplies blood to the body).
The mitral valve can sometimes be 'floppy' in appearance. This will show
up on an
echocardiogram (see cardiac
tests). This is very common and affects around
1 or 2
in every 20 people. It is usually an asymptomatic and benign condition. In
some rare cases mitral valve
prolapse can be inherited in a family and can then be associated with
arrhythmias and sudden death.
This includes abnormalities in the way that the
electrical impulses are conducted through the AV
node due to disease (for example as in myotonic dystrophy), or because
there are additional or 'accessory' pathways as in Wolff-Parkinson-White
over-the-counter and illegal drugs can have potentially dangerous but
usually rare side effects, particularly if too much is taken (an
overdose). These effects include arrhythmias
(disturbance in the heart's rhythm) and sometimes a sudden
Research suggests that
sudden death may be caused infrequently by conditions such
as fits (epilepsy) and severe asthma attacks. Pulmonary embolus (a clot to
the lungs), has become better known recently due to its
association with staying immobile for long periods
during air travel. It can cause a sudden collapse and a rapid
death (for more on this go to technical
Arrhythmic Death Syndrome (SADS)
In around 1 in every 20
cases of sudden cardiac death - up to 500 every year in
the UK - no cause can be found, despite examination of the heart by an
expert cardiac pathologist. The cause of death is therefore
described as 'unascertainable'. This is called
Sudden Arrhythmic Death Syndrome, or SADS.
In the causes
of sads some of the conditions responsible for SADS are described.
Risk in the Young - CRY is a charity started in 1995 to minimise
the incidence and impact of sudden cardiac death in the young. CRY
aims to do this by raising awareness of the conditions that can
lead to sudden death and by providing support and information to
families who have suffered a loss. If you would like more
information please go to the CRY
Web site. If
you would like to talk to someone who can help you please go the