Electrophysiology Studies (EPS) and Radiofrequency Ablation (RFA) Procedures

Patient Experience

  • Reference Number: HEY-451-2020
  • Departments: Cardiology
  • Last Updated: 24 July 2020


This leaflet has been produced to give you general information. Most of your questions should be answered by this leaflet. It is not intended to replace the discussion between you and the healthcare team, but may act as a starting point for discussion. If after reading it you have any concerns or require further explanation, please discuss this with a member of the healthcare team.

What is an Electrophysiological Study (EPS)?

An electrophysiological study is a test that looks at the electrical activity of the heart, allowing the doctor to diagnose and analyse fast or abnormal heart rhythms. It is able to give more detailed information than an external electrocardiogram (ECG). It involves a fine tube called a catheter being inserted into the heart via a blood vessel (vein or artery) in the groin. The end of this catheter has a special electrode tip which stimulates the heart and records the electrical activity allowing the doctor to identify where any abnormalities may be coming from.

What is a Radio Frequency Ablation (RFA)?

Radiofrequency ablation is a treatment that aims to control or correct an abnormal heart rhythm. It is carried out in the same way as an electrophysiological study (EPS) by inserting catheters into heart via the groin.  Radiofrequency energy (heat) is then used to destroy the small area in the heart where the abnormal electrical activity is coming from. This can be done at the same time as the EPS or on a separate occasion.

Why do I need an EPS and RFA?

You will usually have been experiencing symptoms of palpitations or a racing heart beat which can be quite distressing at times for some people. This is because sometimes, the electrical conduction system in the heart travels in a different direction due to extra electrical connections known as ‘pathways’, or due to extra electrical cells within the heart. Often these pathways are present at birth, but may only start to cause symptoms in adulthood. When the heart has an extra beat (an ectopic beat), it can travel up the pathway and travel down the normal conduction system. If this continues, palpitations can start. This means that the heart suddenly starts to race, causing an awareness of a fast heartbeat.

If the abnormal heart rhythm is arising from the upper chambers of the heart, this is known as SVT, or supraventricular tachycardia. This type of heart rhythm disturbance is not life threatening, but can cause unpleasant symptoms and interfere with your quality of life. If the abnormal heart rhythm comes from the lower pumping chambers of the heart (the ventricles) it is called VT, ventricular tachycardia, which can be dangerous, particularly if it is associated with fainting.

Can there be any complications or risks?

These procedures do carry a small amount of risk. Your doctor will explain this to you before you give your consent to have the procedure done. Bruising in the groin area is the most common complication and is usually nothing to worry about.

With RFA there is a small risk of damage to the heart’s normal electrical pathways.  If this happens there is a small risk that you may require a pacemaker. You will have many opportunities to discuss any questions or concerns with the nurses and doctors caring for you before undergoing the test.

How do I prepare for the EPS and RFA?


You will be required to attend the pre-assessment clinic usually between one and four weeks before your EPS or RFA procedure date. At this appointment you will see a nurse practitioner who will take a full medical history, perform a physical examination and explain the EPS or RFA procedure and address any questions and concerns you may have.

You will be seen by a nurse who will perform a baseline nursing assessment. This consists of various questions, such as information about your next of kin, how you usually manage at home, any mobility problems or other issues that we may need to be aware of in order to make your admission as safe and comfortable as possible.

You will be seen by a clinical support worker who will take some blood samples and swabs for MRSA (a type of bacteria responsible for infection) screening. Before you leave the hospital an electrocardiograph (ECG) will be performed.


The catheter is usually inserted in the right groin but both groins can sometimes be used, so you will need to shave an area of approximately 6cm square in the crease of both groins. You may do this at home if you wish or otherwise it can be done on the ward after your arrival.

Eating and drinking 

If you are coming into hospital for a 7.30am admission, you can eat up to 5.00am and drink up until 7.00am the day of the procedure.  If you are coming into hospital for an 11.00am admission, you can eat up to 9.00am and drink up to 11.00am the day of the procedure.


At your pre-assessment appointment, the nurse practitioner will advise you of any medications that need to be stopped prior to the procedure. It is therefore important that you bring an up to date list of your medication with you to the pre assessment clinic or your boxes of tablets if you do not have a current list.

What to bring into hospital with you 

It is advisable to bring slippers or something similar to allow you to walk around the ward safely and a dressing gown. An overnight bag with nightwear and toiletries. Spectacles if worn. All medication in its original packaging. Something to pass the time while you wait before and after the procedure (books, knitting, music to listen to etc)

What will happen?

You should report to the second reception in Cardiology Outpatient Building at the time stated on your admission letter. Once the receptionist has checked you in will be shown to a bed on the day ward and asked to change into a theatre gown and disposable pants.

The nurse who is looking after you for the shift will then check that none of the information you were asked at pre-assessment has changed and your blood pressure, temperature and blood oxygen level will be recorded.

You will have a cannula (a small plastic tube) inserted into your hand or arm and a safety check list will be completed. The cannula allows the staff to administer drugs directly into your blood stream and the checklist is to ensure that you are safely transferred into the Cardiac Catheterisation Laboratory (Cath Lab).

Your doctor will come to see you to talk through what will happen during the procedure and explain the risks involved. If you are happy with this information you will be asked to sign a consent form before going into the Cath Lab for the procedure.

The nurses on the ward will not be able to give you an exact time for your procedure until the doctor has seen all of their patients and decided upon the order of the list. Sometimes this means that you may have to wait until the afternoon before your procedure will take place so it is advisable to bring something to pass the time whilst you wait.

When it is time for your procedure a nurse from the Cath Lab will come to the ward to collect you. They will go through the safety checklist again before accompanying you into the Lab.

Once inside you will be helped onto the X-ray table and asked to lie flat on your back with one pillow for your head. The skin in your groin area will be cleaned with a cold antiseptic solution then your body will be covered with a sterile theatre towel. .

A sheath (similar to the cannula) is then inserted into the blood vessel in your groin and thin flexible tubes (called catheters) are inserted through it and using an X-ray machine are gently guided  into the correct position inside of your heart. You may feel an unusual sensation or discomfort in your chest as the catheters are inserted but this should not be painful.

Once the wires are positioned within the heart, extra beats are delivered using an external pacemaker, which may bring on your palpitations. This is necessary to see the area of the heart where the abnormal rhythm is coming from. It is possible to put the heart back into normal rhythm within a few seconds, by delivering some extra beats, so whilst you may feel a little strange the procedure is completely under the control of the doctor and their team.

Once the abnormality has been found and if it is felt to be necessary, the doctor performing the procedure will then begin to ablate the pathway or area of extra electrical cells. This is done by delivering a form of energy (radio frequency) down the catheter wire to the target area within the heart. The procedure can take up to 4 hours depending on the nature of the problem.

Cardiac radiology

As mentioned earlier your doctor needs to use X-rays to help with your procedure.

There are many benefits associated with the use of x-rays, such as your doctor being able to see what their eyes cannot. X-rays involved with cardiac and interventional procedures lets your doctor see moving pictures of your heart, veins and lots of other organs, so that they can safely insert dyes, stents and other medicines. This is much safer than using invasive techniques such as surgery.

X-rays are exceedingly safe but there is a degree of risk involved – you will receive a small dose of radiation which carries a low (less than one in one thousand) chance of side effects.  Your doctor will never take an X-ray unless the benefit to you exceeds the risk.  This dose of radiation will be equivalent to what you receive in about four years from natural background radiation that is present in the surrounding environment.

What will happen afterwards?

When the procedure is over, the catheters and the sheath are removed from the groin area. A doctor or nurse will press firmly on the area for several minutes to stop any bleeding. When you are back on the ward you will be attached to a cardiac monitor and need to lay flat in bed for 1 hour (after the sheaths are removed) and then complete a further 1 hour of bedrest. Your nurse will also take your blood pressure every so often and keep checking your wound to make sure it is not bleeding and there is no unusual swelling. You will be able to get out of bed and mobilise after the period of bedrest if the nurse is happy with your wound and your blood pressure. If you are well you will be allowed home approximately 4 hours after your return to the ward.

You will be provided with an advice leaflet to take home informing you about what you should and should not do during the short recovery period. Most people recover quickly from the procedure and feel well enough to carry on with simple normal activities of daily life the following day.

You should avoid heavy lifting and more strenuous exercise such as long walks or going to the gym for about 2 weeks afterwards. The DVLA currently state that you may not drive for two days following a successful ablation (six weeks if you carry a HGV licence) but your consultant will probably recommend that you avoid driving for up to one week to allow the catheter insertion site(s) to heal fully (see DVLA website or check in the hospital for current guidance). Time off work will depend upon your profession but often people will take one to two weeks from work.

If you have any holidays booked after the procedure your consultant will usually advise you whether you are able to travel.

Following the ablation, it is quite common to be aware of your own heartbeat, even in normal rhythm. Some people are aware of extra or ‘missed’ beats. Try not to worry too much about these symptoms, which usually settle down with the passage of time.

If you experience your palpitations or a racing heartbeat after the procedure you should seek urgent help if you feel unwell. If it is just a short episode and you do not feel unwell you should report this to your doctor or nurse, as this may indicate that the procedure has not been completely successful.

You will be followed up in the outpatient clinic a few months after the procedure, to see how you are progressing.

Should you require further advice on the issues contained in this leaflet, please do not hesitate to contact the Cardiology Pre-assessment Nurses (01482) 461647.

The British Heart Foundation and the Arrhythmia Alliance websites also have lots of useful information about various cardiac problems which you may find helpful.

General Advice and Consent

Most of your questions should have been answered by this leaflet, but remember that this is only a starting point for discussion with the healthcare team.

Consent to treatment

Before any doctor, nurse or therapist examines or treats you, they must seek your consent or permission. In order to make a decision, you need to have information from health professionals about the treatment or investigation which is being offered to you. You should always ask them more questions if you do not understand or if you want more information.

The information you receive should be about your condition, the alternatives available to you, and whether it carries risks as well as the benefits. What is important is that your consent is genuine or valid. That means:

  • you must be able to give your consent
  • you must be given enough information to enable you to make a decision
  • you must be acting under your own free will and not under the strong influence of another person

Information about you

We collect and use your information to provide you with care and treatment. As part of your care, information about you will be shared between members of a healthcare team, some of whom you may not meet. Your information may also be used to help train staff, to check the quality of our care, to manage and plan the health service, and to help with research. Wherever possible we use anonymous data.

We may pass on relevant information to other health organisations that provide you with care. All information is treated as strictly confidential and is not given to anyone who does not need it. If you have any concerns please ask your doctor, or the person caring for you.

Under the General Data Protection Regulation and the Data Protection Act 2018 we are responsible for maintaining the confidentiality of any information we hold about you. For further information visit the following page: Confidential Information about You.

If you or your carer needs information about your health and wellbeing and about your care and treatment in a different format, such as large print, braille or audio, due to disability, impairment or sensory loss, please advise a member of staff and this can be arranged.

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