AJMALINE PROVOCATION TEST
What is Brugada syndrome?
In Brugada syndrome, the underlying fault may be due to changes within the cells of the heart (ion channels). Ion channels alter the chemical balance of the cardiac cells, by adjusting the amount of electrical charge to them, therefore if the electrical properties of the cell are faulty this can result in a disturbance of the heart rhythm (arrhythmia). In Brugada syndrome the ion affected is the sodium channel. Brugada syndrome is referred to as a channelopathy, this is the term given to conditions where there are changes in genes that determine the ion channels. Your heart is otherwise structurally normal.
In some cases, genes have been identified for Brugada syndrome however, the list identified is not complete. It is therefore not possible to be absolutely sure that a patient has not got Brugada even if genetic screening is negative. Please remember that if you are advised to have genetic screening it may take some time to perform.
In Brugada Syndrome some patients may be at risk of developing fast heart rhythms, which may result in blackout or very rarely sudden death. If the ventricles start beating at an abnormally fast rate this results in the heart not working as efficiently, which can cause symptoms of weakness, dizziness, chest pain, shortness of breath or even collapse. However, it is important that you remember that the majority of patients who have Brugada do not experience arrhythmias and feel perfectly well.
It is very important that if you have a close family member diagnosed with the condition or who dies young that all remaining relatives are screened for Brugada.
Your doctor suspects that you may have Brugada syndrome and he has advised you to have a simple test known as a ajmaline challenge to confirm the diagnosis.
Why do I need a ajmaline challenge?
Your doctor has advised you to undergo a ajmaline challenge to exclude Brugada syndrome. Ajmaline challenge is a well-established clinical test. It is undertaken to see if you have a hidden form of Brugada syndrome. The purpose of the test is to use a drug called ajmaline to uncover the characteristic ECG changes.
What is a ajmaline challenge?
Ajmaline is a drug known as a sodium channel blocker. It is routinely used by doctors to prevent abnormal heart rhythms these drug are called antiarrhythmics. Ajmaline is used by doctors in this test as it blocks the faulty sodium channels and unmasks ECG changes in those patients who have Brugada. In patients with normal cardiac cells ajmaline has little or no effect on the ECG.
Your doctor will administer the drug through a vein in your arm and record your ECG every three minutes; ECG’s record the electrical signals (activity) from inside your heart. The ECG will record how your heart reacts to ajmaline, this allows your doctor to collect detailed information about the cause of your potential arrhythmia. The ajmaline challenge is undertaken in a ward setting with cardiac monitoring. Children are taken to the intensive care area for monitoring during the test.
Is the ajmaline challenge safe?
Yes, the ajmaline challenge is safe. However, as with any procedure, there are potential risks. The risks are outlined below and will be fully explained by our doctors before you have your procedure. The ajmaline challenge is performed safely in both children and adults.
Risks of the procedure
In our experience complications associated with this procedure are very rare. It is important that you are aware that on rare occasions there are some risks associated with this procedure that may occur either during, or after the procedure. These risks as outlined below can be treated and are rarely life threatening.
At the time of the procedure
It is common to experience a metallic taste in your mouth during the administration of the ajmaline. Again, you may experience visual disturbance such as double vision. Such side effects usually resolve quickly once the infusion is completed. Very rarely, in less than 1% of patients the ajmaline may cause your heart to go into a very fast ventricular rhythm, if this happens the doctor will need to correct your arrhythmia quickly by cardioversion. Cardioversion is a treatment for heart rhythms that are irregular. Before you are cardioverted you will be given a short-acting sedative to make you sleepy. Once you are asleep a special machine called a defibrillator is used to send electrical energy to the heart muscle to restore the normal rhythm and rate.
After the procedure
There is a very low risk that you may experience an arrhythmia after the ajmaline has finished. We therefore keep you in hospital overnight and monitor your heart rhythm. You will be able to go home the following day.
If you are taking medication you do not need to stop taking it.
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 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 ablation procedure and its 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.
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 the ajmaline during the procedure. You will then be given a hospital gown to wear, this allows us to record the ECG easily.
You do not need to worry and we encourage your family can stay with you during the test.
During the Ajmaline challenge
It is unlikely that you will experience any adverse sensations at all during the test. Although you may feel very anxious during the procedure, the staff involved in your care are very aware of your possible anxieties. Your doctor and nurse will stay with you and be there to reassure you throughout the test. There will be equipment by your bedside, this is used to monitor your heart rhythm and record your blood pressure. You will be awake during the test and able to talk to us.
The nurse or doctor will connect you to the ajmaline infusion, this may sting a little and you may feel some mild discomfort. You will then be connected to the ECG machine. Once the infusion is running your doctor will record the ECG at three-minute intervals for the duration of the test. You should not feel anything. However, sometimes patients do complain of a metallic taste in mouth, numbness around the lips or blurred vision these side effects usually resolve quickly once the test is completed. If you do have any uncomfortable symptoms during the test for example, chest pain, dizziness, shortness of breath, please tell your nurse or doctor. In very rare cases, a ventricular arrhythmia may be induced by ajmaline, if this happens your doctor will correct your rhythm quickly. Do not be alarmed that the doctor is looking closely at the ECG during the test, it does not mean there is anything wrong. The doctor must look closely at your ECG to note changes.
After the doctor has performed the test, you will be kept in the monitored bed and continue to be monitored for approximately one hour after the procedure. After this time you will then be moved to the ward area.
After the procedure
After the procedure you will be moved to the ward area where your heart rhythm will be monitored for the next 2-3 hours. The IV line will then be removed after this time. On return to the ward you will be able to eat and drink. The nurse will check your blood pressure, pulse. 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.
The doctor will show your ECG’s to your consultant. Your doctor will then discuss the findings of the test with you and your family.
When will I know the result of my procedure?
After your test your doctor will discuss the ECG recordings with your consultant. The doctor will then discuss results and ongoing treatment plan with you and your family.
What treatment options are available for me?
If the test is negative, you may not require any treatment at all, or you may be advised to undergo further tests. If the test is positive, you may be advised to undergo further tests. The main successful treatment for Brugada syndrome is the implantable cardioverter defibrillator (ICD). An ICD will not prevent the arrhythmia but can treat it. Your consultant will discuss the risks and benefits with you on an individual basis.
You will normally be able to go home on the same day. It is important to ask a family member or friend to collect you and drive you home.
When can I resume my normal activities?
You can resume your normal daily activities (walking, bathing, showering, etc.) and return to work upon discharge from hospital.
Will I come back here for follow-up?
Upon discharge from the hospital, you will receive specific follow-up instructions by your consultant. Our doctors will write a detailed letter to your GP describing your hospital stay and treatment.