Interventional Cardiology

Pulmonary vein isolation

What is pulmonary vein isolation (PVI)?


Pulmonary vein isolation (PVI) or pulmonary vein ablation is a treatment for atrial fibrillation (AF). Atrial fibrillation is an abnormal heart rhythm that originates in the top chambers of the heart (atria). The goals of treatment for atrial fibrillation include regaining a normal heart rhythm (sinus rhythm), controlling the heart rate, reducing symptoms, and reducing the risk of blood clots and stroke. 

Other options are available to treat atrial fibrillation, including lifestyle changes, medications, catheter-based procedures and surgery.

  • Clinical studies have shown that in many cases, the extra electrical signals that cause AF are around the pulmonary veins on the left side of the heart.
  • Pulmonary vein isolation (PVI) is an option that electrically isolates "hot spots" in the pulmonary veins that trigger AF.
  • A catheter (a thin, flexible tube) is used to guide tiny electrodes into the heart where the pulmonary veins are and heat-energy is delivered through the tip of the catheter in wide encircling lesion sets around the pulmonary veins.
  • Bursts of radiofrequency energy is applied in a circle around the connection of the left upper and lower pulmonary veins to the left atrium.
  • Heat energy destroys the tissue and causes scar tissue to form. This scar tissue blocks the extra electrical signals from the pulmonary veins so the area can no longer generate or conduct fast, irregular impulses.
  • This process is carried out around the opening of each of the four pulmonary veins. As a result, the heart usually returns to a normal sinus rhythm.


Position of PVI catheters

Why do I need the procedure?

Pulmonary vein ablation may be most appropriate for:

  • Treatment of patients who have paroxysmal or short term persistent atrial fibrillation
  • Patients who are not responding well to antiarrhythmic drugs
  • Patients who have had complications from antiarrhythmic drugs
  • Patients in whom the left atrium has not been damaged or enlarged by other cardiac disease

Prior to the procedure, a series of test and evaluation procedures will be conducted to see if this procedure is appropriate for you. Pre-testing includes a history and physical examination, an electrocardiogram (ECG) and an echocardiogram. Heart monitoring may also be required.

A couple of weeks prior to your procedure you will need a CT scan (computed tomography) to determine whether a transoesophageal echocardiogram is required on the day of the procedure. You will also need blood tests and your Electrophysiologist will prescribe a course of anticoagulant drugs, for at least one to two months prior to your procedure. You will need to continue to take the prescribed anticoagulant drug for at least three months after your procedure or as advised by your Electrophysiologist.

What will I experience during the procedure?

The procedure is conducted in an angiography suite (“cath lab”) specifically set up for EP at Intra. Your Electrophysiologist will be assisted by highly trained staff including an Anaesthetist, Anaesthetic technician, specialist Nurses and highly trained Electrophysiology technicians.

  • Prior to the procedure, a small intravenous needle ("IV line") will be inserted into a vein in your arm. This allows drugs to be injected directly into the vein if necessary.
  • A nurse will shave and cleanse the area where the catheters will be inserted - usually the groin area but it could be arm, shoulder or neck also. Shaving and cleansing make it easier to insert the catheters and help avoid infection. A local anaesthetic is injected into the skin through a tiny needle to numb the area.
  • A small incision is made in the skin and a needle is used to puncture the blood vessel (usually a vein) into which the catheters will be inserted

In some countries this procedure is done under local anaesthetic, but we feel that it is safer and more comfortable to use a general anaesthetic.

This is primarily because the procedure may take between three to six hours, during which time you will need to lie very still. There is also a possibility of needing to carry out a transoesophageal echo during your procedure. 

It is therefore like any other operation performed under general anaesthesia – you will not be aware of anything during the procedure. Your progress will be monitored by an anaesthetic team (Anaesthetist and Anaesthetic technician) throughout your procedure.

How should I prepare for my procedure?

A couple of weeks prior to your procedure you will require a CT scan and blood tests. Intra staff will book the CT Scan for you and notify you of the details as well as give you a blood form for the necessary blood tests. You will also be prescribed a course of anticoagulant medication to take for one to two months before the procedure.

  • Fasting: You must not have anything to eat or drink six to eight hours before your procedure, unless the Anaesthetist tells you otherwise. You may continue to drink a small amount of clear fluids to take medications.
  • Medication: Be sure to check with your doctor several days before your procedure as you may be asked to stop taking certain medications for up to a week prior to the procedure. This can help get more accurate test results. Also bring a list of all the medications you are currently taking. It is important for the doctor to know the exact names and dosages of any medications that you take.
  • Allergies and previous reactions to contrast (x-ray dye): Please inform Intra staff at the time of booking your procedure if you have any known history of allergies, particularly allergies to x-ray contrast and seafood.
  • Diabetes: If you are a diabetic you should tell the Intra staff at the time of booking. You may need to discuss your insulin dose with your cardiologist.
  • Transport: Make arrangements with a family member or friend to drive you to the hospital.

On the day of your procedure, please make your way to the Mercy Hospital Reception where they will be expecting you. You will be admitted to a hospital ward and transferred to our facility for your procedure.

What happens after my procedure?

  • Following your procedure you will be transferred to a ward within the Mercy Hospital for recovery.
  • You will be monitored by a team of coronary care nurses. If you feel any palpitations of dizziness, please let the nursing staff know.
  • A nurse will check your groin for any bleeding. It is best if you try to lie still and avoid bending the affected leg to avoid bleeding from the puncture site.
  • You will stay in hospital overnight and can usually return home on the day following the procedure. It is important to ask a family member or friend to collect you as you cannot drive yourself.
  • The puncture site will have a small dressing that can be removed the next day. Be sure to keep the area clean and dry until it has healed. If you notice any swelling, redness or oozing please let your GP know.
  • You can resume normal daily activities (walking, bathing, showering etc.) on returning home. However, you should not lift heavy objects or strain in any way to allow the puncture site to heal.
  • You will be able to return to work within a week or two of having the procedure, unless your job involves heavy lifting.
  • The prescribed anticoagulant medication must be continued for a further three months following your procedure. On average it takes three months for your heart to recover from the procedure and you may experience palpitations (skipped heart beats) during that time.
  • It is advisable not to drive a motorcar for at least 48 hours after your procedure. If you usually drive a bus or truck, it is advisable not to drive for up to six weeks following your procedure. Your doctor will discuss this with you following your procedure.
  • It is also not advisable to travel within two months of your procedure as there is a risk of atrio-oesophageal fistula formation. This risk is increased by air travel.

What are the risks?

During the procedure
  • Occasionally catheter electrodes may accidentally cause damage to blood vessels when they are being moved into position inside the heart. The likelihood of this occurring is between 3-5%. Serious injury to the blood vessels that requires a surgical procedure to repair is extremely rare and occurs in less than 1% of patients.
  • During the procedure, the Electrophysiologist makes a small hole in the heart muscle (transeptal puncture) to gain access to the pulmonary veins on the left side of the heart. Usually this hole will seal up quickly after the procedure. On rare occasions the hole will remain open – if this happens, surgery may be required to close it.
  • Very rarely during this transeptal puncture process, the catheter electrodes may puncture a major blood vessel. In such cases, emergency cardiac surgery is required to repair the blood vessel.
  • When the catheters are being placed within the heart, they may puncture the heart muscle, causing blood to collect around the heart. This is called a cardiac tamponade and has approximately a 0.5 - 1% chance of occurring. If this happens, the doctor may insert a drain to remove the blood.
  • The catheter electrodes can puncture the lung wall. The likelihood of this occurring is less than 1%. On the rare occasions this does occur, air leaks out of the lungs and collects in the space between the lung and chest wall, which results in a partially or completely collapsed lung. This is called a pneumothorax and if it occurs, the doctor may need to insert a drain to reinflate the lung.
  • Similarly, if the catheter electrode does puncture the lung wall, blood can leak out of the lungs into the pleural cavity (space between the lungs and chest wall). This is called a haemothorax and needs a drain insertion to reinflate the lung.
  • The risk of developing a blood clot that travels to the lungs, brain (causing a stroke) or lower legs is extremely rare with a less than 1% chance of happening.
  • The pulmonary vein ablation procedure may last from three to six hours. Each patient is different. Please let your family know that the preparation and recovery time take several hours, so they could plan accordingly.
After the procedure
  • Bruising and bleeding at the groin, being the catheter entry point, is common following the procedure. This usually disappears within a week without causing a problem.

Your doctor will have explained to you, and it is important to remember, that the PVI ablation is not always successful. If the procedure is unsuccessful, it may be possible to repeat the procedure at a later date.

Please also remember that it is not uncommon to experience palpitations (extra heart beats) sporadically for a few weeks after your procedure until the small scars created in the heart have healed. It may feel as though your irregular heart rhythm has returned and then suddenly stops. These sensations are normal and should not cause alarm. However, if you do feel your abnormal heart rhythm has returned, please get in touch with your doctor.