Electrophysiological studies
What is an
electrophysiological (EP) study?
Electrophysiological (EP) studies allow the
heart's electrical activity to be analysed in
great detail. This test has revolutionised the way we understand
and treat fast or abnormal heart
rhythms. However, at the moment it is only available
at some hospitals in the UK.
How is an EP study done?
The test usually takes about 2-3 hours, but can sometimes take
longer. The hospital will ask you not to eat or drink anything for
a few hours beforehand. Thin flexible tubes, called
catheters are placed into a vein, usually in the
groin. You will have a local anaesthetic injection which numbs the
area where the catheters are put in. You may also be given
sedation to help relax you during the procedure.
As the tubes are inserted, you may feel a sensation or
discomfort in your chest, but this should not be painful. The
catheters are gently moved into the position in the heart, where
the special electrode tip stimulates the heart and
records the electrical activity. This may make you feel as if you
are having palpitations and can make some people feel dizzy. You
should tell the staff if you experience any symptoms. Abnormal
heart rhythms often happen during the test. These can help with the
results of the test but occasionally may need to be treated during
the EP study.
What happens after the test?
When the test is over, the catheters are removed. Sometimes
there may be a small amount of bleeding when they are taken out. A
nurse or doctor will press on the area for a short while to stop
any bleeding. You will be asked to stay in bed for a while
afterwards.
The test is sometimes done as a day case. However, most people
will need to stay in hospital overnight. You may feel tired
afterwards, but you should feel back to normal within a few
days.
What can the test show?
During the test, you are continuously monitored with an
ECG. This can help to
diagnose abnormal heart rhythms and to identify which areas of
your heart are affected. If you have an abnormal heart rhythm, the
test can also show if it is being controlled effectively with
certain medicines.
If the cause of your abnormal heart rhythm is found, the doctor may
be able to treat the problem during the test by using
radio frequency electrical energy to destroy the
areas inside the heart which are causing the abnormal rhythm. This
is called catheter ablation.
Are there any risks?
An EP study does involve a very small amount of risk. Your
doctor will explain this to you before you give your consent
to have the test.
If there is bleeding from the area where the catheter is
inserted, it can sometimes leave a haematoma (which is when blood
collects under the skin). This can feel uncomfortable and cause
bruising.
There is a small risk of damage to the heart's normal electrical
pathways. If this happens, you may need to be fitted with an
artificial pacemaker.
Your doctor will not recommend that you have this procedure
unless he or she thinks the benefits outweigh the risks.
Further information
Tests for heart conditions booklet
Heart rhythms booklet
Rhythm not blues video
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