Read about the drugs to avoid with Brugada here.
This condition was first identified in the early 1990s. It is an uncommon condition in the western world but seems to be much more common among young men in South East Asia.
In the western world it affects mainly young and middle-aged adult men. It has been associated with mutations in the same sodium channel that is affected in long QT syndrome, but this appears to account for only 1 in every 5 people with the condition. The sodium channel behaves abnormally in that movement of sodium ions into the cells is restricted. This results in particular changes on the ECG but no abnormalities in the structure of the heart. Other genes have been described as being involved in Brugada syndrome that produce calcium ion channels and a protein in the cell surface (membrane) that interacts with the sodium channel. They have, however, only been detected in a small number of carriers.
CRY Consultant Cardiologist Professor Sanjay Sharma talks about Brugada syndrome below. This video was published in 2011 – please note that the incidence of Brugada is now (July 2017) considered to be 1 in 2,000.
What are the symptoms?
Most people with Brugada syndrome may have no symptoms at all. In others, the most common symptoms are blackouts. Some people may notice palpitations due to ectopic (extra) beats.
Are there any physical signs?
There are no associated physical signs.
How is it diagnosed?
Diagnosis involves having an ECG. The changes characteristic of Brugada syndrome may appear on the ECG continuously or come and go, or they may not show at all. Sometimes the presence of a fever or certain medicines can bring out the ECG changes and this may be a period when there is higher risk of blackouts or cardiac arrest If they do not show up on the ECG, there are tests that can make the ECG changes visible. These are called provocation tests and involve having a short injection of an antiarrhythmic drug while you are having an ECG. The drugs most commonly used for this are ajmaline and flecainide. There is some controversy, however, about how much reassurance a negative result should give. Researchers have found that, in some carriers who have already been identified by genetic testing, changes on the ECG are not seen even with a provocation test. However, in these people the level of risk does appear to be low.
Genetic testing is not very useful for diagnosing Brugada syndrome because mutations have been found in only a small proportion of people known to have the syndrome.
Treatment and advice
If you are a carrier of Brugada syndrome you should avoid certain medications that might worsen your condition. You should also treat all fevers with medications that will reduce your body temperature such as paracetamol or ibuprofen. If your fever remains high you should attend hospital for an ECG or monitoring as required. It is standard practice for high risk carriers to have an implantable cardioverter defibrillator (ICD) fitted as this is a very successful form of protection. Unfortunately it can be very difficult for doctors to decide how to treat those people who do not get symptoms but who have an abnormal ECG. An electrophysiological study (EPS) may help to identify those people who do or do not need an ICD although there is great controversy about its true role. Research has suggested, however, that people with normal ECGs and no symptoms should be safe without any treatment. It is unusual for children to be at high risk.
Special advice about living with Brugada syndrome
There are certain things which have been shown to increase the risk of a dangerous heart rhythm in this condition, but that are readily avoidable. Two of these are having a high fever, and sleeping with a full stomach.
Fevers have been shown to increase the risk of developing the Brugada pattern on your ECG, which can in turn lead to a potentially fatal heart rhythm. Therefore if you have a fever, for whatever reason, you should treat this quickly and aggressively e.g. with paracetamol. If you are unsure what to do, or the fever does not subside, then seek medical advice.
Sleeping on a full stomach may seem like a very odd thing to mention! However there is science behind this. In all people, having a full stomach stimulates a nerve called the vagus nerve, which can in turn affect the heart. In people with Brugada syndrome, this can trigger an abnormal heart rhythm at night. To avoid this, you should leave at least 2-3 hours before your last meal of the day and going to bed at night.
Watch CRY’s myheart cardiologist, Dr Michael Papadakis, talk about things to avoid if you have an ion-channel disease below.