Ajmaline Challenge
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The heart has its own electrical conduction system. The conduction system sends signals through the heart to make it beat in a regular rhythm. Various problems with this system can cause an
abnormal heart rhythm (arrhythmia). The heart may beat too quickly (tachycardia), too slowly (bradycardia) or irregularly which may affect the hearts ability to pump blood around the body.
This in turn may cause cardiac symptoms including palpitations, collapse, blackouts (syncope), chest pain, shortness of breath and sudden death.
Why has my doctor recommended that I have an Ajmaline Challenge?
Your doctor is trying to test whether you have a condition known as Brugada syndrome. There are a number of ways to test for this syndrome (e.g. an ECG, a Flecainide drug challenge, genetic
screens). Ajmaline drug challenges are an effective test to investigate patients for Brugada Syndrome and this is why your doctor has ordered this test.
What is Brugada Syndrome?
Brugada Syndrome is a rare disease affecting around 1 in 2000 people in the UK. In Brugada Syndrome the heart is structurally normal, but patients may be at risk of developing a fast heart rhythm due to changes within the ion channels of the heart. Ion channels alter the calcium balance of cardiac cells, by adjusting the amount of electrical charge to them. Therefore if the electrical properties of a cell are faulty this can result in a disturbance of the heart rhythm (arrhythmia). Patients who develop a fast heart rhythm may suffer from a blackout or, rarely, sudden death. The ion channel involved in Brugada Syndrome is a sodium channel. Genetic testing can be useful but only around 20% of patients with Brugada Syndrome will have an identifiable gene change. This means that genetic testing alone cannot be used to exclude the diagnosis.
I have been advised to have an Ajmaline Challenge; what does this involve?
If your doctor suspects that you may have Brugada Syndrome he will advise you to have a simple test known as anAjmaline challenge to confirm your diagnosis. Ajmaline is a drug which blocks sodium channels. As it blocks the faulty sodium channels it unmasks ECG changes in patients with Brugada Syndrome. Ajmaline is an unlicensed drug which means that it has not been through the extensive regulatory mechanism of more commonly used drugs.
Why is an unlicensed drug being used?
Ajmaline is commonly used around the world to test patients for Brugada Syndrome. Flecainide is an alternative which is a licensed product; however, it is not as effective as Ajmaline, and is not as safe, as it is much slower to be cleared from the body.
What will happen next?
You will be invited to attend an appointment, with a nurse, the week before the Ajmaline challenge. This appointment will involve an assessment by a nurse who will weigh you and take some blood. You will be able to discuss all the information in this leaflet and ask any questions you may have. You will also be asked to sign a consent form by a doctor on this day.
What will the Ajmaline Challenge involve?
Your Doctor or Nurse will administer the drug through a vein in your arm (over 5-10 minutes); your ECG will be recorded at the same time. The ECG will record how your heart reacts to the Ajmaline and will show if the test is positive or negative. Your pulse and blood pressure will be monitored throughout the test.
What are the possible side effects from the Ajmaline challenge?
The drug challenge is safe, but as with any procedure there are potential risks. Complications associated with the procedure are rare and can be treated. If we see evidence of a complication developing we would immediately stop the drug infusion. It is very rare for any of the side-effects to be life threatening. It is important that for the duration of the procedure, if you feel any palpitations, dizziness, or uncomfortable symptoms you should inform your nurse or doctor.
Side Effects you may experience include:-
Metallic taste in the mouth
Visual disturbance such as double vision
Fast or Slow heart rate
Dizziness
Tingling in your hands or feet
These side effects resolve once the procedure is complete.
Very rarely ( less than 1%) the drug can cause your heart to go into a very fast and potentially dangerous rhythm (ventricular tachycardia or fibrillation). This would require treatment with a shock (defibrillation), which would be done under sedation where time permits. Your doctor will discuss the results of the test with you in detail and describe any future investigations or treatments which may be required. If you are diagnosed with Brugada Syndrome and assessed to be at high risk, then you would be offered an implantable defibrillator (ICD) to protect you. Genetic testing can be useful and may also be arranged.
On the day of your procedure
Please do not have anything to eat four hours prior to the test, you can drink clear fluids prior to the test On arrival in the cardiology department you will be taken to the day ward and introduced to the staff who will be caring for you. The procedure will be explained to you and if you have any worries or questions please do not be afraid to ask. Before the procedure you will have ECG’s and
observations recorded. It is important for you to tell your doctor or nurse if you have any allergies or have had previous reaction to drugs or other tests. Please also inform them if you are unwell
with flu or a cold on the day of the test.
A small cannula will be inserted into a vein in your arm to allow us to give you the drug during the procedure. You will also wear a hospital gown to make it easier to record the ECG. A nurse will stay with you throughout the test. There will be equipment by your bedside which is used to monitor your heart rhythm and record your blood pressure. During the procedure you will be awake and able to talk.
For the duration of the challenge you will be connected to the ECG machine. The nurse will connect you to the infusion which may sting a little. Once the infusion is running, your nurse will record the ECG at regular intervals. After the test you will be kept in the monitored bed for at least 1- hour.Your blood pressure and pulse will continue to be checked and the cannula will be removed before you go home. Following your discharge from hospital you will be able to resume your normal daily activities, as the drug passes out of your body in a few hours.
It is recommended that you do not drive, and that you have someone with you for the rest of the day after the test. We would suggest returning to work the following day.
Other Useful information can be found at:
www.bhf.co.uk/heart-health/conditions/brugada-syndrome
www.heartrhythmallilance.org/
If you have any concerns please contact us on the numbers given below or speak to your nurse on the day of procedure.
CONTACT DETAILS
Milton Keynes University Hospital NHS Foundation Trust
Cardiac Angiography Unit
Department of Cardiology
Milton Keynes Hospital
Standing Way
Milton Keynes
MK6 5AD
Cardiac Angiography & Day Bed Unit 01908 996539
(Mon – Fri 8am – 5pm)
References for the information available on request.