What is a heart attack?
Your heart is a powerful muscular pump that drives blood around
your body. To keep your heart healthy, the muscles of your
heart need to be supplied with blood by the coronary arteries.
If one of the coronary arteries becomes blocked - for example
by a blood clot - part of your heart may be starved of oxygen
and become permanently damaged. This is what happens if you
have a heart attack.
A heart attack usually causes severe pain in the centre of
the chest. The pain lasts for more than 15 minutes, and may
last for many hours. The pain usually feels like a heaviness
or tightness which may also spread to the arms, neck, jaw,
face, back or stomach. In some cases the pain may be mistaken
for indigestion. There may also be sweating, light-headedness,
nausea or shortness of breath. A heart attack may cause the
rhythm of the heart to become disturbed.
However, sometimes a heart attack is 'silent' and produces
little discomfort. It may even remain undiscovered until you
have a medical investigation for other symptoms or a routine
medical examination.
A heart attack is sometimes called a coronary thrombosis or
myocardial infarction.
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What causes a heart attack?
A heart attack is a sudden and often dramatic event, but it
is usually the result of a process that has been going on
for many years. The walls of your coronary arteries may have
become narrowed by a gradual build-up of fatty material. This
condition is called 'atherosclerosis'. The fatty material
is called 'atheroma' or atheromatous plaque and as time progresses
this becomes harder and more fibrous sometimes with calcium
deposits also.
The walls of these diseased arteries may crack and blood cells,
called 'platelets', become attracted to the damaged areas.
A clot (or thrombus), that includes fibrous material called
'fibrin', may form on top of this. This can suddenly and completely
block off your artery. If your artery is blocked for more
than a few minutes, the muscle cells in the area of your heart
supplied by that artery may become permanently damaged. This
is called a heart attack. Often, the amount of muscle damage
is small and, once the heart attack is over, there is enough
good muscle left for the heart to carry on its work satisfactorily.
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What brings on a heart attack?
Heart attacks often happen to people who seem to have been
perfectly well. In other cases, a heart attack may follow
weeks, months or years of angina.
Heart attacks can start at any time of the day or night, either
when you are resting or being active. A heart attack can occasionally
be brought on by doing energetic activity which you are not
used to, or by intense physical or emotional stress.
We do not know why heart attacks happen when they do, but
we know a lot about why people get coronary heart disease.
There are 4 major lifestyle 'risk factors' - things which
increase people's risk of having a heart attack. These are:
· Smoking
· High blood pressure
· High blood cholesterol, and
· Physical inactivity
Other lifestyle factors may also play a part. These include
drinking too much alcohol, excessive salt intake and overweight
and obesity.
Heart attacks can run in families. One hereditary condition,
which causes coronary heart disease, is called familial hyperlipidaemia
(or hypercholesterolaemia or FH).
People with diabetes are also more likely to get coronary
heart disease, although the reason for this is not clear.
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What's the difference between a
heart attack and angina?
Angina occurs when the coronary arteries have become narrowed
and the supply of blood and oxygen to the heart muscle is
decreased. The supply of blood and oxygen may be enough when
you are resting, but not enough if your are exercising or
under emotional stress.
The chest pain that comes with angina is usually brought on
by exercise or emotional stress. It is less severe than the
pain of a heart attack and does not last as long. With angina,
there is not usually any sweating or nausea, but these symptoms
often occur with a heart attack. A nitrate tablet or spray
is very effective in relieving angina, but will not completely
relieve the pain of a heart attack. Severe indigestion symptoms,
which are not relieved by medication, may be a heart attack.
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What is a cardiac arrest?
During a heart attack, there may be disturbances in the heart
rhythm. The most serious form of this is called 'ventricular
fibrillation". This is when the electrical activity of
the heart becomes so chaotic that the heart stops pumping
and quivers or 'fibrillates' instead. This is a cardiac arrest.
It can be corrected by giving a large electric shock through
the chest wall, using a device called a defibrillator. This
is often successful in restoring a normal heartbeat and afterwards
the person can do just as well as if they had not had the
cardiac arrest.
If a cardiac arrest occurs, the person loses consciousness
almost at once, no pulse can be felt, and breathing may stop.
This is the most extreme emergency. Unless resuscitation is
started within 3-4 minutes, the person may suffer permanent
damage to the brain and other organs. Resuscitation means
inflating he lungs, pumping the heart by external cardiac
massage, and using mouth-to -mouth resuscitation to keep the
circulation and breathing going until the ambulance arrives.
Ambulance staff are now trained in advanced resuscitation
and all emergency ambulances carry a defibrillator.
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How do they treat a heart attack?
A heart attack is treated as an emergency because of the severe
pain and the risk to life if the person's heart stops beating
(cardiac arrest).
The first priority is treatment to relieve the pain. Ambulance
staff may use a mixture of nitrous oxide and oxygen (Entonox)
through a face mask to help relieve the chest pain. They may
also give you an aspirin to chew. This helps to improve the
anti-clotting effect of the treatment you will get when you
reach the hospital. If the pain is still severe, a doctor
or nurse will inject a powerful painkiller (usually a form
of morphine) into a vein.
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What happens in hospital?
Once the person gets to hospital, pain relief is a priority.
Oxygen will be given to those who are breathless or in shock.
It is important to get to hospital as soon as possible because
treatment is now available that will help to dissolve the
clot that is blocking the artery. This treatment is called
'thrombolysis'.
Thrombolysis involves injecting a thrombolytic drug such as
Streptokinase into the bloodstream. Ideally the injection
should be given within 90 minutes of the heart attack starting
and at the latest within 6 hours. Thrombolysis can be given
later, but it is less effective as time goes by.
If you have a Streptokinase injection, you should be given
a card to carry with you because you should not have a repeat
dose. If you have another heart attack, a different thrombolytic
drug can be used instead.
Some patients can have urgent balloon angioplasty/stenting
rather than clotbusting drugs to unblock the clot and underlying
narrowing which in general gives a better long term outcome.
This treatment can only carried out in specialist centres
though is likely to become more common in the next five to
ten years
If you have just had a heart attack, you will probably be
cared for in the cardiac care unit of the hospital - the CCU.
You will have an electrocardiogram (ECG) to assess your heart
rhythm and to help diagnose the heart attack. A heart monitor
will be attached to you so that the nurses can check for any
disturbances in your heart rhythm. You will also have blood
tests to assess the extent of the heart attack.
If necessary, you may be given more painkillers through a
vein in your arm. The amount given can be increased or decreased
until your chest pain has eased.
Other tests may be carried out to find out how severe the
heart attack was and to help decide on the best form of treatment.
The tests may include:
· A chest x-ray
· An echocardiogram
· Exercise ECG
· A radionuclide test
· An MRI scan, or
· Coronary angiography
When the doctor is confident that you are making good progress,
he or she will make arrangements for you to transfer to a
general ward and will suggest that you gradually start moving
around again.
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What treatment might I have in
hospital?
If you have had a heart attack you may be given drugs for
3 main reasons:
· To prevent a further heart attack (for example Aspirin,
anticoagulants, beta-blockers or anti-arrhythmic drugs.
· To relieve breathlessness and heart failure (for
example diuretics or ACE inhibitors).
· To treat angina (for example nitrates, calcium antagonists
or beta blockers).
If tests show that one or more coronary arteries are severely
narrowed and that drug treatment is not likely to be successful,
you may be advised to have:
· Coronary angioplasty, or
· Coronary bypass surgery
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What happens to my heart after
a heart attack?
After a heart attack, the area of the heart muscle that was
damaged will be replaced by scar tissue. This takes from a
few days to a few weeks.
Within 2-3 months, the hearts of many heart attack patients
are functioning just as well as they were before the attack.
However, sometimes a heart attack can cause more severe damage
to the heart, with the result that the pumping action of the
heart is not as good as before. This can lead to breathlessness,
tiredness and swelling of the ankles. Also, some people continue
to experience angina (heaviness or tightness in the chest
on exercise) because there is still narrowing of the coronary
arteries. If you have any of these symptoms, tell your doctor.
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Will it happen again?
Many people wonder if they will have another heart attack.
Once the first few days are over, the chance of having a second
attack is not great and, as time goes by, it becomes less
and less. The risk still remains, but it can be greatly reduced
by adopting healthy habits and taking suitable medicines.
This is called 'secondary prevention'. A rehabilitation programme
will help you and your family choose a healthier lifestyle.
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What happens on a cardiac rehabilitation
programme?
Rehabilitation programmes vary throughout the country, but
most programmes cover 3 areas:
· Exercise
· Relaxation
· Information on lifestyles and treatments
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Exercise
Before you start the rehabilitation programme you will have
an initial assessment to find out how much exercise you can
safely do. A physiotherapist or an exercise physiologist can
then carefully work out a programme of exercises for you,
tailoring the programme to your individual needs.
At the beginning of each session you will do warm-up exercises
which involve stretching your muscles. All the exercises will
be carefully explained to you. The exercises will be 'aerobic'
(exercises that help to improve your heart and circulation).
You will be encouraged to increase your exercise gradually
over the weeks of the rehabilitation programme. It is very
important that you work within your limits and follow the
advice given to you. At the end of each exercise session you
will do 'cool-down' exercises to stretch out your muscles
and prevent them from aching the next day.
It is normal to feel anxious about exercise after a heart
attack. However, attending rehabilitation classes can help
give you the confidence to become active again.
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Relaxation
You will be able to practice different relaxation techniques
and find one that suits you. You will also find out how important
relaxation is for people who have had a heart problem.
If possible, encourage your partner or a family member or
friend to go along with you. This will help lessen their fears
as well and give them the chance to ask any questions.
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Information on lifestyles and treatment
This may involve structured but informal sessions within your
group. You may cover one or more topics in each session and
will have the opportunity to ask any questions. Topics include:
· How the heart works, what can go wrong, and why and
how people develop coronary heart disease.
· How to identify your own risk factors relating to
coronary heart disease.
· Diet and healthy eating. You may also have the opportunity
to discuss your own diet with a dietician.
· How to recognize your own stress and how to manage
it.
· If you are a smoker you will be encouraged to give
up and will be offered advice on how to go about it.
· Medication. You may be able to discuss your medications
with a doctor, nurse or pharmacist.
· Practical issues such as driving and holidays.
· Going back to work. People who have had an uncomplicated
heart attack will usually be able to return to work. You can
talk to a member of the cardiac rehabilitation team about
the type of work you do. They will help to assess how easily
you might take up your job again and when you should return
to work.
Attending cardiac rehabilitation classes gives you the opportunity
to ask questions and talk about any worries you may still
have.
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How can I reduce my risk of further
coronary heart disease?
The major risk factors for coronary heart disease that you
can do something about are:
· Smoking
· High blood pressure
· High blood cholesterol, and
· Physical inactivity
Obesity, drinking too much alcohol, and excess salt intake
can also increase the risk of coronary heart disease. Your
risk of further coronary heart disease will depend on how
many of the above risk factors you have, as well as the strength
of the individual risk factors. Knowing about your risk factors
may encourage you to deal with them and help you feel some
power to control your heart disease.
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If you smoke, stop smoking
Continued smoking after a heart attack doubles the risk of
having another attack. If you do smoke, now is the time to
stop. This is the single most important step you can take
to help your recovery. From the moment you stop, the risk
of heart attack starts to decline and is halved within 2 years
of giving up smoking.
However, giving up is much easier said than done. Talking
to friends and relatives who have stopped, joining a give
up smoking group and discussing other measures with your GP
or practice nurse will help you. Ask your GP or pharmacist
about products such as nicotine patches as these can really
help.
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Control high blood pressure
Successful treatment of high blood pressure can produce a
20% reduction in death rates from coronary heart disease.
High blood pressure increases the risk of a heart attack and
of strokes, and over time can cause the heart muscle to become
less efficient.
If you have high blood pressure, it is essential to control
it. The goal for people who have had a heart attack is to
have a blood pressure under 140/85mmHg. If you have diabetes
the goal is below 130/80mmHg. Sometimes this can be achieved
by reducing weight, increasing physical activity and cutting
down on alcohol and salt. However, many people also need to
take medication to lower their blood pressure.
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Watch your cholesterol
If you have had a heart attack or if your doctor has diagnosed
coronary heart disease, the level of cholesterol in your blood
will be measured. The aim is to have a total cholesterol of
under 5mmol/l. If your blood cholesterol is even slightly
above desirable levels, you can greatly benefit from reducing
it.
A healthy diet will help. This means cutting down on fats
in general, especially saturated fats, which are found mostly
in meat and dairy products. It has been estimated that reducing
the intake of saturated fat by 10% is linked with a reduction
of about 20-30% of deaths from coronary heart disease.
In practice, many people with coronary heart disease also
need drugs to achieve the low levels of blood cholesterol,
which are known to bring the greatest benefit.
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Eat plenty of fruit and vegetables … and antioxidants
People who eat more than 5 portions of fruit and vegetables
a day are less likely to have heart disease. Exactly why is
unknown, but it thought to be due to the antioxidant vitamins
they contain. However, there is as yet insufficient evidence
that taking vitamin tablets has the same effect. Even if you
already have coronary heart disease, it is still helpful to
eat plenty of fruit and vegetables.
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Fish and fish oils
Eating oily fish two to three times a week may help to reduce
your level of triglycerides (fatty substances found in the
blood), and prevent blood clots from forming in your coronary
arteries. The particular oil in fish that has these beneficial
effects is known as 'omega-3'. It is found mainly in oily
fish such as herring, kippers, mackerel, pilchards, sardines,
salmon, fresh tuna, trout and anchovies.
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Keep active
Physically inactive people in the UK have about double the
risk of heart attack. Even if you have already had a heart
attack, a programme of exercise reduces the risk of another
attack. The activity needs to be aerobic - that is when the
muscles of the arms, legs and back are used rhythmically and
steadily so that breathing and heart rate are increased. Examples
of aerobic activity include brisk walking, swimming, cycling
and some gardening.
Physical activity has other benefits too, including a reduced
heart rate and lower blood pressure while you are resting,
improved cholesterol levels, better control of diabetes, less
angina, earlier return to work, and fewer visits to hospital.
These benefits also apply to people who have had a heart attack
or heart surgery and to those with heart failure.
If you have recently had a heart attack, going on a rehabilitation
programme is a very good way of making sure that you exercise
at a level that is safe for your. If you have had a heart
attack at some time in the past, ask your doctor how much
and what sort of activity you can safely do.
If you suffer from angina, you can still exercise, but the
activity should be within the limits of your angina or breathlessness.
Also, avoid very cold and windy weather and do not try to
'walk through' chest pain.
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Control your weight
It is important to control your weight, not just to help your
heart but also for your general fitness. By keeping close
to the recommended weight for your height, you will keep your
blood pressure down and reduce the workload of your heart.
If your doctors feel that you are significantly overweight,
they will ask the hospital dietician to give you advice on
how to reduce your weight. If you have any questions once
you get home about what or how much you should be eating,
ask your GP or district nurse. You can also ask questions
at your cardiac rehabilitation programme.
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If you need to lose weight
If you fall in the overweight, fat or very fat category, you
need to lose some weight. Don’t try to lose the extra
weight too quickly. Losing weight slowly and steadily (about
1lb a week) is healthier, and you're more likely to keep the
weight off for good. If you are very overweight, losing even
10% of your weight will benefit your health.
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Control diabetes
Men with diabetes have about 3 times the risk of a heart attack
compared to those without diabetes. Women with diabetes have
about 5 times the risk of heart attack. Exactly how diabetes
causes heart disease is not clear. It is however, very important
to make sure your blood sugar is well controlled. Increasing
physical activity, controlling your weight and taking regular
medication will all help.
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