Brugada syndrome is a heart rhythm disorder that was first described in 1192 by the Spanish cardiologists Pere, Josep and Ramón Brugada. Brugada syndrome associates the triad of a conduction block in the right branch of the bundles that conduct electricity to make the heart beat to a persistent elevation in the electrocardiogram (ECG) of a segment called ST and sudden death, recovered or not.
- It belongs to the so-called channelopathies, which are alterations of the channels that allow the production of electrical energy that favors the contraction of the heart.
- Most patients with Brugada syndrome can remain asymptomatic, making it difficult to truly assess its prevalence.
- The prognosis of patients once treated is good, but without treatment the risk of death is high.
Brugada syndrome occurs in patients who do not suffer a structural alteration at the basic cardiac level, that is, there is no congenital or acquired anatomical alteration that is the cause of this disease. In fact, this syndrome is included within what is known as channelopathies, which are alterations of the channels that allow the passage of ions (sodium, potassium, calcium, ...) through cell membranes, a passage with which produces the electrical energy that allows the heart to contract.
It is not a very common disease; its prevalence is estimated to be about 5 cases per 100,000 inhabitants. It is a disease that occurs much more frequently in Asia, although cases are also detected each year in both Europe and North America. It is between 8 and 10 times more frequent in men than in women and usually appears around the fourth decade of life, despite the fact that cases have also been detected during childhood and in younger patients.
In principle, it follows an autosomal dominant inheritance pattern, that is, it is enough that only one of the copies of the genes involved is altered for the disease to manifest itself, but it has been seen that this pattern does not always follow and there are quite a few cases of patients with Brugada syndrome without a family history.
Several genes involved in the appearance of this syndrome have been detected, several of them located on chromosome 3, but there are multiple mutations that have been detected and studied that have a bearing on the genesis of this disease.
Most patients with Brugada syndrome can remain asymptomatic, making it difficult to truly assess its prevalence. It has been reported that between 17% and 42% of patients have suffered a syncope or an episode of sudden death recovered as a consequence of a ventricular arrhythmia throughout their life. Typically the arrhythmias produced in patients with Brugada syndrome occur at rest or even during nighttime rest, that is, they are not dependent on greater or lesser physical activity. Likewise, 20% of affected people may also suffer supraventricular arrhythmias, and may experience palpitations or dizziness. In children, high fever can be a trigger for arrhythmias in children with Brugada syndrome.
For the diagnosis of Brugada syndrome, it is necessary to have the alterations inherent to this entity, with right bundle branch block and ST segment elevation. However, the ECG of these patients can be highly variable, sometimes even being normal. For these cases, provocation tests for ECG alterations are usually performed using certain drugs, always with the patient monitored and in a hospital setting.
The main treatment for Brugada syndrome consists of the implantation of an implantable cardioverter-defibrillator (ICD), which allows the device to trigger if a ventricular arrhythmia occurs and allows the heart to return to a normal rhythm. Its placement is recommended to all patients who have suffered symptoms (syncope, sudden recovery death) or to asymptomatic patients in whom arrhythmias have been pharmacologically induced in provocation tests. The main drawback of the DAI is that the rate of unnecessary shocks is high.
There are pharmacological alternatives to ICD, especially quinidine, which can be used as an alternative to ICD or as concomitant treatment, or in pediatric patients. Isoproterenol has also been used as an alternative treatment and the use of cilostazol is being evaluated, but there are few studies on this as yet.
The prognosis of these patients once treated is good, but without treatment the risk of death is high, especially in patients who have suffered syncope or had ventricular fibrillation induced with typical ECG changes in drug induction tests. 62% of patients with this syndrome who have presented an episode of recovered sudden death present a new episode in the following four and a half years if no therapeutic intervention is performed, with the consequent risk to life.
In case of having suffered syncope, an episode of sudden death or having close relatives diagnosed with Brugada syndrome, it is essential to be followed up by a cardiology team. He has a large cadre of specialists in heart disease. Find out about their coverage and most importantly
Take care of your heart!