Electrophysiological (EP) studies
Electrophysiological (EP) studies allow
your doctor to look at your heart's electrical activity in great
This test has revolutionised the way we understand and treat
fast or abnormal heart rhythms.
Sometimes your doctor will also carry out a catheter ablation - a treatment that can
help control or correct an abnormal heart rhythm - during this
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 you relax
during the procedure.
- 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. You may also feel a
sensation or discomfort in your chest, but this should not be
- During the test you are continuously monitored by the nurses,
doctors and technicians carrying out the procedure.
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, some 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?
An EP study can diagnose abnormal heart rhythms and identify
which areas are affected.
Abnormal heart rhythms often happen during the test. These can
help with the results of the test but sometimes may need to be
treated during the EP study.
If the cause of your abnormal heart
rhythm is found, the doctor will sometimes want to treat
the problem during the test by using catheter ablation. This treatment uses
radio frequency electrical energy to destroy the areas inside the
heart which are causing the abnormal rhythm.
If you have an abnormal heart rhythm, an EP study can also show
how well your medication is controlling your condition.
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 was placed, 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 only recommend that you have an EP
study if he or she thinks the benefits outweigh the
Our scientists are fighting for every heartbeat
Your donations help us fund more pioneering research into
improving our understanding of heart rhythms, such as
Professor David Eisner’s work at the University of