Electrophysiological (EP) studies
Electrophysiological (EP) studies allow the heart's
electrical activity to be analysed in great
This test has revolutionised the way we
understand and treat fast or abnormal heart
However, at the moment it is only available at some hospitals in
How is an EP study done?
- The test usually takes about 2-3 hours, but can sometimes take
- 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
- 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
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
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 that the
catheter was placed in, you might develop a collection of
blood under the skin, which is called a
haematoma. It can be uncomfortable and cause
bruising, but this should go down after a few days.
However, contact your doctor if you have any concerns.
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
Your doctor will not recommend that you have an EP
study unless he or she thinks the benefits outweigh the