The Brugada syndrome is a congenital, autosomal dominant hereditary cardiomyopathy. The disease is one of the ion channel diseases and is due to a mutation. The treatment includes the implantation of an automatic defibrillator.
What is Brugada Syndrome?
The heart pumps blood to the individual tissues of the body. The blood supply also corresponds to a supply of oxygen, nutrients and messengers. All types of body tissue need oxygen and nutrients to stay alive. The functions of the heart are therefore vital. They are controlled by the autonomic nervous system.
Heart disease can cause life-threatening conditions. The heart disease can be divided into different groups. One of these groups is cardiomyopathy. This heterogeneous group of diseases includes various diseases of the heart muscle that cause mechanical or electrical dysfunction.
Often they cause a thickening (hypertrophy) or enlargement and dilatation of the heart chambers. Cardiomyopathies can occur in an acquired form, but they can also be congenital. Brugada syndrome is a congenital cardiomyopathy, which is one of the ion channel diseases. These diseases are associated with disorders of the muscle conduction and cause arrhythmias.
Brugada syndrome was classified as an independent disease in the 1990s and was first described by cardiologists from Pagua. The incidence of the disease is given as five to 66 per 10,000 people. The disease is more common in Southeast Asia than in Europe or North America. The syndrome affects men eight times more often than women.
Causes
In the meantime, Brugada syndrome, along with other, rather rare heart diseases, is classified under the genetic heart disease. The cause of the disease is therefore in the genes. A genetic mutation causes the disturbance of the ion channel and thus the cardiac excitation.
In all ion channel diseases, the genetic change affects protein molecules that control the transport of ions through the cell membrane of the heart muscle. Due to the changes in these control molecules, more (gain-of-function) or fewer (loss-of-function) sodium and potassium ions are transported through the membranes in ion channel diseases. These processes change the electrical properties of the heart in Brugada syndrome.
In the meantime, the responsible genetic defect has been identified in a small number of Brugada syndrome patients. In up to 25 percent of those affected, a mutation in the SCN5A gene located on chromosome three in the 3p21 gene locus appeared to be responsible for the arousal disorder. This gene encodes the control proteins of the ion channel in the DNA. Due to the mutation-related change in protein, the molecules can only fulfill their tasks to a limited extent.
Symptoms, ailments & signs
Patients with Brugada syndrome suffer from a repolarization disorder of the heart muscle cells. However, this repolarization disorder does not necessarily have to cause symptoms. A certain proportion of the patients show no symptoms at all, or at least consciously do not notice anything about the muscle disease.
In other cases, symptoms such as sudden attacks of unconsciousness (syncope) become noticeable. Even the cardiac arrest can threaten in certain circumstances. However, all symptoms of the heart muscle disease only appear after the onset of cardiac arrhythmias.
The most common cardiac arrhythmias in the context of Brugada syndrome are polymorphic ventricular tachycardias and ventricular fibrillation. These cardiac disorders are due to the changed repolarization properties of the heart muscle. Repolarization refers to the period of time that the heart muscle needs to recover after an excitation and the associated contraction.
Only through repolarization can a contraction take place again. In individual cases, the first symptoms of Brugada syndrome appear in newborns. In most cases, however, they do not show up until the third or fourth decade of life.
Diagnosis & course
The only diagnostic signs for Brugada syndrome are typical changes in the EKG. These changes correspond to a right bundle branch block-like clinical picture with anomalies of the ST segment in leads V1 to V3. The EKG changes can only be seen temporarily. The symptoms can be aggravated by the administration of ajmaline or procainamide.
This means that the ECG is often the only way to make a targeted diagnosis when these drugs are administered. For detailed diagnostics, the ECG changes are divided into three different classes. These classes have different specificities for the syndrome.
In terms of differential diagnosis, it is important to differentiate Burgada syndrome from diseases such as arrhythmogenic right ventricular dysplasia. The patient’s prognosis depends primarily on the time of diagnosis and the age of the manifestation.
Complications
Since there is no causal cure for Brugada syndrome, surgery must be performed to keep the patient alive. As a rule, a defibrillator is also built into the patient’s body for this purpose. In most cases, Brugada syndrome is unnoticeable to the patient, which can make diagnosis difficult.
Complications only arise as a result of the unconsciousness attacks. In the worst case, cardiac arrest can occur when unconscious, resulting in death. These disorders develop when malformations and disorders develop in the heart. The affected person is thus in a life-threatening condition and suffers from so-called ventricular fibrillation.
The Brugada syndrome can often be observed in babies and small children, whereby rapid and, above all, early treatment is possible. In order to compensate for the heart problems, the installation of an automatic defibrillator is necessary, which prevents cardiac arrest. As a rule, there are no further complications, although the patient is dependent on taking medication.
Due to the cardiac arrhythmia, the person concerned cannot perform any particularly difficult tasks or sports and is therefore restricted in his everyday life. If treatment can completely relieve the heart condition of Brugada syndrome, reduced life expectancy is not to be expected.
When should you go to the doctor?
If Brugada syndrome is suspected, a doctor should be consulted immediately. For example, if there is a sudden loss of consciousness that cannot be traced back to any external cause, this indicates a serious illness that needs to be diagnosed quickly. If there are several cases of heart disease or heart attacks in the family, it is advisable to clarify the health of the heart at an early stage. This is especially true if cardiac arrhythmias or heart attacks have already been identified in the past.
Other warning signs that should lead you to a doctor immediately are sudden seizures, dizziness and other circulatory problems. In the event of unconsciousness, the emergency doctor must be alerted immediately. Immediate respiratory arrest indicates sudden cardiac death, which can only be survived with immediate resuscitation and defibrillation. First aiders should take first aid measures and, in the case of typical symptoms (dilated pupils, skin discoloration on the fingernails and mucous membranes, etc.), perform a heart pressure massage. If the outcome is positive, a longer stay in the hospital is necessary.
Treatment & Therapy
Causal therapy is not available for patients with Brugada syndrome. The aim of symptomatic treatment is to prevent cardiac death. The most important step in this regard is the implantation of an automatic defibrillator. An indication for this treatment step arises for all patients with documented serious cardiac arrhythmias.
Conservative drug therapies with beta blockers are usually contraindicated in patients with Brugada syndrome. There is a risk of ventricular fibrillation, especially when the heart rate is low, which is increased by the administration of these drugs. Patients with recurrent ventricular fibrillation are sometimes given sympathetic medication that temporarily suppresses symptoms.
Since active ingredients such as quinidine prolong the action potential of the conduction of excitation, the administration of these active ingredients can in individual cases reduce the number of ECG changes. Presumably, this medication also reduces the risk of ventricular fibrillation.
Individual trigger areas can also be electrophysiologically obliterated (ablation). In the past, this approach has eliminated the arrhythmias of some patients with Brugada syndrome.
Outlook & forecast
As a rule, Brugada syndrome cannot be treated causally. Those affected are therefore dependent on purely symptomatic treatment, the main aim of which is to prevent cardiac death. If no treatment is given for Brugada syndrome, the patient will die of cardiac death.
For this reason, a defibrillator is used during treatment, which works automatically and can correct the disturbances of the heart. However, the life expectancy of the patient may be significantly limited despite treatment. The administration of medication can also have a positive effect on the course of the disease. In most cases, the defibrillator can alleviate the symptoms to such an extent that there are no particular restrictions in everyday life. The patient has to forego strenuous physical activity in order not to strain the heart unnecessarily.
In rare cases, a circulatory collapse or ventricular fibrillation can occur despite the use of the defibrillator, which requires emergency medical treatment. The further course of Brugada syndrome is therefore also heavily dependent on the patient’s lifestyle and cannot generally be predicted.
Prevention
So far, Brugada syndrome can only be prevented through genetic counseling in the family planning phase. The genetic disorder is inherited as an autosomal dominant trait. Couples with an increased inheritance risk may decide against having their own children and consider adopting them instead.
Aftercare
Follow-up care is usually neither possible nor necessary for Brugada syndrome. Due to the hereditary mutation, the disease cannot be treated causally, so that the person affected is dependent on an automatic defibrillator. Usually this defibrillator is surgically inserted when the syndrome has been diagnosed, so early diagnosis is paramount to avoid sudden cardiac death.
The patient is also dependent on taking beta blockers to minimize heart problems. The person affected should also avoid stress and unnecessary tension in order not to strain the heart unnecessarily. Regular examinations by a cardiologist are also very useful to prevent complications.
Furthermore, a healthy lifestyle with a healthy diet can have a positive effect on the disease and increase the life expectancy of the person affected. Because Brucellosis Brugada Syndrome is an inherited condition, the patient should undergo genetic counseling to avoid recurrence of the syndrome.
In the event of ventricular fibrillation, first aid measures must be provided, and the emergency doctor should also be notified immediately. Further treatment is then carried out by the emergency doctor or in the hospital.
You can do that yourself
Brugada syndrome is a hereditary disease. Those affected cannot take self-help measures to treat the disease causally. However, you and your loved ones can help prevent sudden cardiac death, the worst consequence of the disorder.
People with a family history of Brugada syndrome should familiarize themselves with the symptoms and the course of the disease so that they can consult a doctor in good time. Despite all due caution, there is no need for undue concern. Most people with Brugada syndrome will not experience any symptoms throughout their lives.
Nevertheless, especially if the syndrome has already occurred in the family, people should take certain symptoms seriously and have them examined as soon as possible. Cardiac arrest does not occur immediately in many patients, and other signs can usually be observed beforehand. These include, in particular, dizziness, seizures and loss of consciousness for no apparent cause. In these cases, a heart specialist should be consulted immediately so that the disease can be discovered and treated before life-threatening cardiac arrhythmias occur.
In the event of an acute circulatory collapse due to ventricular fibrillation, the survival of the person concerned depends to a large extent on immediate adequate first aid measures. If Brugada syndrome has been diagnosed and the patient shows the first symptoms, it is indicated that the social near-field undergoes relevant first aid training. The employer should then also be informed so that in the event of a breakdown, the right reaction can also be taken at the workplace.
