Atrial Fibrillation Ablation (Pulmonary Vein Isolation) Procedure

Patient Experience

  • Reference Number: HEY1223/2021
  • Departments: Cardiology
  • Last Updated: 14 May 2021


This advice sheet has been produced to give you information about an atrial fibrillation ablation also known as a pulmonary vein isolation procedure. It is not meant to replace discussion between you and the healthcare team, but may act as a starting point for discussion.  If after reading it, you require further explanation, please discuss this with a member of the healthcare team.

What is a Pulmonary Vein Isolation?

A pulmonary vein isolation ablation is a procedure which is offered if you have been diagnosed with atrial fibrillation (a specific type of irregular heart beat), which is causing some unpleasant symptoms or which cannot be managed effectively by medication.

Why do I need a Pulmonary Vein Isolation?

 You will have been diagnosed with an abnormal heart rhythm called atrial fibrillation which has been causing you symptoms, most commonly breathlessness, palpitations, tiredness and possibly light headedness.

Atrial fibrillation (AF) is an abnormal heart rhythm in which the upper chambers of the heart (the atria) are not beating normally. This can make the heart muscle less efficient and increases the risk of developing a blood clot in the heart chambers which could cause a stroke. In anticipation for the procedure your doctor will usually have prescribed an anticoagulant, which stops the blood from clotting normally and reduces the risk of stroke.

By returning the heart to a normal rhythm, we aim to make your heart work more efficiently and hopefully eliminate some of the symptoms we believe to be associated with the atrial fibrillation. In some cases, it may even be possible for the anticoagulant and some other medication to be discontinued at a later date.

What are the complications and risks?

Like all invasive procedures pulmonary vein isolation does carry a small amount of risk. Death and serious complications related to the procedure are very rare but can still, unfortunately sometimes occur.

The doctor recommending the procedure will have explained these risks to you in clinic and will talk you through them again on the day of your procedure, but in summary they are as indicated below:

  • 1 – 2% (1 – 2 in 100) risk of serious complications such as stroke, heart attack or cardiac tamponade (a collection of blood in the sac which surrounds the heart which compresses the heart)
  • Less than 1% (less than 1 in 100) risk of damage to the oesophagus (gullet), permanent paralysis of the diaphragm, bleeding, bruising or damage to the blood vessels in the groin, pulmonary vein narrowing. Permanent paralysis of the diaphragm is more likely to occur with cryoenergy. The function of the phrenic nerve that supplies the diaphragm will be monitored by pacing the nerve and inducing hiccoughs during the procedure. Fortunately, even if the paralysis occurs it recovers within 24 hours in 95% of cases and can take up to 3 months in the remaining 5% of cases 

How do I prepare for the procedure?

Take time to read this leaflet and share the information with your family and friends so they can help and support you, especially if they are taking care of you afterwards.

Before your procedure you may need to have an additional test to check that you do not have any blood clots in the atria or any other structural heart problems. This may be either a transoesophageal echocardiogram (TOE) or a CT scan but you will be given further information about this if it is required.

You may also be required to take blood thinning medication (if you do not already take it) before your procedure.


You will be required to attend the pre-assessment clinic before your planned procedure date. At this appointment, the Nurse Practitioner will confirm your personal details and medical history, perform a physical assessment, take some blood samples and perform swab tests for MRSA (a bacteria responsible for infection) screening. You will also be required to have an electrocardiogram (ECG) performed. The Nurse Practitioner will talk to you about the procedure, and address any questions or concerns you may have. Any changes to medication that are required will also be explained at this appointment. 

It is very important that you bring all of your current medications or a current prescription and your International Normalised Ratio (INR / Warfarin) log (a record of blood clotting test results) with you to this appointment.


In most cases you may eat up to 5.00am and drink up to 7.00am on the day of the procedure.

However, if you are having a general anaesthetic you need to be nil by mouth from 12 midnight the day before admission, i.e. nothing at all to eat or drink, including chewing gum and boiled sweets from midnight.

The nurse practitioner will confirm arrangements at your pre-assessment appointment. 


You will need to shave an area of both groins. You may do this at home if you wish or otherwise it can be done on the ward after your arrival if you are unable to do this yourself. 


Some medications may need to be stopped prior to the procedure, this will be discussed at your pre-assessment appointment.

Cardiac radiology

As mentioned above 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 like everything in life, there is a degree of risk involved – you will receive a small dose of radiation which carries a low (less than 1 in 1,000) chance of side effects. Furthermore, your doctor will never take an X-ray unless the benefit to you exceeds the risk. To put this into context, 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 happens during the procedure?

There are four pulmonary veins which carry blood back to the heart from the lungs. The area where the tissue from the left atrium and these veins meet is where the majority of the extra signals which cause AF originate.

During the procedure we aim to block these signals by destroying small areas of tissue and forming scar tissue. This is done by using either radio frequency energy (heat) or cryo energy (cold). The success and complication rates are similar for both methods.

The procedure is performed by gaining access to the heart via veins in the groin. In most cases this is done under local anaesthetic so you will be awake but conscious sedation will be given during the ablation to make it more comfortable.

You will lie flat on your back on an X-ray table in the Cardiac Catheter Laboratory.  Your body is covered with a sterile theatre towel and the skin in your groin area is cleaned with a cold antiseptic solution.  A small injection of local anaesthetic is used to numb the groin area.  This will sting a little but will make the rest of the procedure more comfortable.

Once the anaesthetic has been injected and taken effect, several long fine wires (catheters) are passed from the veins in the groin into the heart under X-ray guidance. You may feel a strange sensation or discomfort in your chest as the tubes are inserted but this should not be painful. If it does feel painful tell the doctor and you will be given pain relief medication. Tubes will be passed into the left side of the heart by means of a needle puncture through the centre of the heart. This is called a trans-septal puncture and this is a critical part of the procedure.  This hole will usually close off by itself once the tubes are withdrawn in the right side of the heart.

Once in the heart the catheters are moved around to identify the areas of abnormal heart tissue. Once the abnormal tissue has been identified scar tissue is created in one of 2 ways. Either small burns are made using radio frequency or a balloon is inflated with cold gas, around the entrance of the veins. This should not be too uncomfortable as you will have been given the conscious sedation. During the procedure a blood thinner called heparin will be administered through a drip to reduce the risk of clots forming around the tubes in the left side of the heart. The procedure can take between 2 – 4 hours.

In some circumstances the procedure is performed under a general anaesthetic. Your consultant will discuss this with you if it is felt to be appropriate for you.

What happens after the procedure?

When the ablation is complete the catheters may be withdrawn from the heart and removed from the groin. If this is the case someone will press firmly on the puncture sites for a few minutes to stop the bleeding and a small dressing will be applied once bleeding has stopped.

In some cases, the catheters may be left in place and will be removed when you are back on the ward once it is safe to do so.

Once back on the ward you will need to lay flat in bed for at least an hour, then remain in bed for a few more hours to minimise the risk of problems from the puncture site. You will be able to walk around the ward for the remainder of your stay provided you have no problems with your leg.

You may need to stay in hospital overnight in order for us to monitor your heart rhythm but should be able to go home early the next morning providing all is well.

Sometimes you may be in atrial fibrillation after the procedure and this does not necessarily mean it has not been successful, we just need to manage it with a cardioversion a month or so after discharge.

You will be given an advice sheet following the procedure to guide your recovery, but please be aware that you will usually be advised not to drive for 7 days following the procedure.

You must have a responsible adult to collect and escort you home after your procedure.  If you are unable to arrange for a friend or relative to bring you in and take you home please the patient transport department of your local ambulance service may be able to help.

Should you require further advice on the issues contained in this advice sheet, please do not hesitate to contact the Clinic (01482) 461647 or

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

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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.

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