Why do I need an AV Node Ablation?
Your doctor has advised you to have an AV node ablation as you have been diagnosed with an abnormal heart rhythm (atrial fibrillation), which has proved difficult to treat with medication. An AV node ablation and insertion of a permanent pacemaker will regulate your heart rate and provide relief from the symptoms you have been experiencing. This procedure stops the fast, irregular impulses from the atria, the upper chambers reaching the ventricles, the lower chambers.
What is an AV Node Ablation?
The AV node slows the electrical signals travelling from the upper chambers of the heart (atria) to the lower chambers (ventricles). During the procedure, the doctor will use a special ablation catheter to deliver radiofrequency energy (heat energy) to block the AV node. The use of radiofrequency energy creates a scar, which stops the fast, irregular impulses from the atria reaching the ventricles, this will stop your fast heart rate. After the AV node is ablated your underlying heart rate will be too slow you will, therefore, need a permanent pacemaker to keep your heart beating at a normal pace. A pacemaker is a small battery-operated device that sends out electrical signals to start a heartbeat when your heart is beating too slowly. It is important to remember that an AV node ablation will not convert atrial fibrillation to sinus rhythm; it will only control the number of impulses reaching the ventricles.
This procedure is performed under a local anaesthetic, with sedation, which will help you to relax.
The procedure is undertaken in a special room called the EP lab using X-ray screening; therefore, if you think you may be pregnant you should let us know before the procedure.
Is the AV Node Ablation safe?
Yes, AV Node ablation is safe however, with any procedure, there are potential risks. The risks will be fully explained by our doctors before you have your procedure.
Risks of the procedure
Although the majority of patients who undergo an AV node ablation do not experience complications, it is important that you are made aware that on rare occasions there are some risks associated with the procedure that may occur either during, or after the procedure. If you are known to have underlying coronary heart disease the procedural risks are slightly increased.
It is important for you to remember that the risks outlined below can be treated and are rarely life threatening.
In our experience complications associated with this procedure are very rare.
At the time of the procedure
- Occasionally, the catheter electrodes can accidentally damage the blood vessels when being moved into position within the heart. The risk of this happening to you is between 3%-5%. Serious injury to the blood vessels requiring a surgical procedure to repair the damage is extremely rare and occurs in less than 1% of patients.
- Very occasionally, the catheter electrodes can puncture the lung wall. Air leaks out of the lungs and collects in the space between the lung and chest wall, resulting in partial or complete collapse of the lung. This is called a pneumothorax. If this happens the doctor may need to insert a drain to reinflate your lungs. The risk of this happening to you is less than 1%
- Again, very occasionally the catheter electrodes can puncture the lung wall. Blood leaks out of the lungs into the pleural cavity, the space between the lungs and the walls of the chest. This is called a haemothorax. If this happens the doctor will need to insert a drain to reinflate your lungs. The risk of this happening to you is less than 1%
- The risk of developing blood clots that travel to the lungs (pulmonary embolism), brain (stroke) or lower leg (DVT) is extremely rare, less than 1%.
After the procedure
- Bruising and bleeding in the groin is common following the procedure. However, this usually disappears within a week and does not cause a problem.
- On rare occasions the ablation procedure is not successful. Your doctor will discuss the success rate with you on an individual basis before you sign your consent form. If the procedure is unsuccessful it may be possible to repeat it at a later date.
Please refer to the separate pacemaker booklet for associated risks related to pacemaker implantation.
If you are taking medication to control your heart rhythm you may continue to take your tablets before the procedure. Again, if you are taking warfarin (blood thinner) it is very important you check with the EP co-ordinator before your admission, as you may need to stop taking it before you have the procedure. If you have any questions please talk to the EP co-ordinator about the medicines that you are currently taking.
Sometimes, before undertaking the procedure your doctor will perform a transoesophageal echo (TOE) to check that you do not have any blood clots in the atrium.
Before the procedure
On your arrival to the ward you will be introduced to the nurse who will be looking after you. The nurse will talk to you and your family about your hospital admission and answer any questions you may have. Before the procedure, you will have blood tests taken and an electrocardiogram (ECG) recorded. A doctor will also see you and explain the procedure to you, he will then ask you to sign a consent form; this is to ensure you understand the procedure and the associated risks. If you have any worries or questions please do not be afraid to ask. It is important to tell your nurse or doctor if you have any allergies or have had a previous reaction to drugs or other tests. If you are having the procedure done under a general anaesthetic, you will also talk to an anaesthetist.
Before the procedure a nurse will help to get you ready. The doctor or nurse will need to insert a small needle into a vein in your hand (cannula) this is to allow the doctor to give you drugs during the test. You will also be asked to shave your groin and upper chest and be given a hospital gown to wear.
You will be asked not to eat or drink anything for 4 hours before your procedure. If you are diabetic, your nurse will discuss your tablets/insulin dose with you, because not eating may affect your blood sugar levels.
Please tell your family that the procedure may take a couple of hours so that they do not worry.
During the procedure
You may feel very anxious during the procedure, however the staff involved in your care are aware of your possible anxieties. Whilst you are in the catheter lab a nurse will stay with you and be there to reassure you throughout the procedure. There is a lot of equipment in the room, which is used to monitor your heart rhythm. You will be awake during the procedure however; to help you relax your doctor will give you a short acting sedative.
The doctor will inject a local anaesthetic into your groin to numb your leg, this may sting a little and you may feel some mild discomfort. When the local anaesthetic has taken effect, the doctor will insert a small tube (sheath) into your groin, you should not feel any pain, if you do, please let your doctor know. Through the sheath the doctor will gently thread several flexible wires (catheter electrodes) into your heart, these special wires will find and ablate (destroy) the AV node. The catheters are about the size of a small drinking straw. The catheters are carefully moved into position within your heart under x-ray screening. You should not feel any pain during this part of the procedure.
Once the ablation catheter is in place, the doctor will locate the AV node. He will then deliver a small amount of radiofrequency energy (heat energy) directly onto the node and ablate (destroy) it to create a scar. You may feel a slight burning sensation or heaviness in your chest during this part of the procedure. It is important to remember that in the case of an AV node ablation the creation of scar tissue will block the hearts normal conduction system and this is why you will need to have a pacemaker fitted, this is because scar tissue cannot transmit electrical impulses.
Once the AV node is ablated the doctor will then insert the permanent pacemaker and cover it with a sterile dressing.
If you do have any uncomfortable symptoms during the procedure, for example, chest pain, dizziness, shortness of breath, please tell your nurse or doctor.
After the procedure is completed the catheter and IV line will be removed. Firm pressure will be applied to your groin where the catheter was inserted to stop you from bleeding.
After the procedure
After the procedure you will be moved to the recovery area where you will be monitored for a short time before returning to the ward. On return to the ward you will need to rest for a few hours. You may feel a little sleepy until your sedation has worn off. The nurse will record an ECG, check your blood pressure, pulse and feel your foot pulses. The nurse will also check your groin and pacemaker site for any bleeding. It is important that you remain in bed for approximately two hours after the catheters have been removed. You should also try to lie still and avoid bending your affected leg; this is to prevent any bleeding from the puncture site. After this time of rest, you will be able to get up. You can however rotate your ankle and flex your foot, this will help your circulation and reduce your risk of developing a blood clot (DVT) in your lower leg (calf). On return to the ward you will be able to eat and drink normally. The nurse will remove the small needle in your hand. If you feel any palpitations or dizziness after the test, please let the nurse know. You will also have a chest x-ray to make sure that you do not have a pneumothorax (pocket of air) in your lung and to check the position of the pacemaker.
When will I know the result of my procedure?
After your procedure your doctor will usually discuss the results and treatment plan with you and your family.
You will normally be able to go home after your pacemaker check the following day. It is important to ask a family member or friend to collect you and drive you home. If you are being discharged home the same day as your procedure we would advise you to have someone stay with you for the night. Prior to your discharge, your doctor or EP nurse will advise you regarding the medicines you will need to take, or stop and your follow-up care.
Caring for your wound
You will have a small dressing covering your pacemaker site. It is important to keep the area clean and dry until it has healed. If you notice any swelling, redness or oozing from the site please contact the office as soon as possible.
When can I resume my normal activities?
You can resume your normal daily activities (walking, bathing, showering, etc.) upon discharge from hospital. The only restriction is straining or lifting heavy objects for a few weeks so that the pacemaker wires can become embedded and the incision site can heal.
When can I go back to work?
Unless your job requires you to lift heavy objects, you can return to work in a day or two.
Will I still need to take warfarin?
Yes, AV node ablation does not change atrial fibrillation to sinus rhythm, therefore blood clots can still form and potentially you are still considered at risk of stroke.
The DVLA's guidance is that after an AV node ablation and pacemaker insertion you should not drive a car for 1 week. If you hold a Group 2 PSV licence (lorries/buses), you are not able to drive for 6 weeks.
Will I come back here for follow-up?
Upon discharge from the hospital, you will receive specific follow-up instructions. Our doctors will write a detailed letter to your GP detailing your hospital stay and treatment.