Brugada Syndrome: Causes, Symptoms & Treatment

Brugada syndrome is a congenital, autosomal-dominant inherited cardiomyopathy. The condition is one of the ion channel diseases and results from a mutation. Treatment includes implantation of an automatic defibrillator.

What is Brugada syndrome?

The heart pumps blood to the individual tissues of the body. The blood supply corresponds to an oxygen, nutrient and messenger supply at the same time. Every type of body tissue needs oxygen and nutrients to stay alive. Thus, the functions of the heart are vital. They are controlled by the autonomic nervous system. Diseases of the heart can cause life-threatening conditions. Heart diseases 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. They often cause thickening (hypertrophy) or dilatation of the heart chambers. Cardiomyopathies can occur in acquired form, but can also be congenital. Brugada syndrome corresponds to a congenital cardiomyopathy, which is one of the ion channel diseases. These disorders are associated with disturbances in muscle excitation conduction and cause arrhythmias. Brugada syndrome was classified as a distinct disorder in the 1990s and was first described by cardiologists from Pagua. The incidence of the disease is reported to be 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

Brugada syndrome is now included among the genetic heart diseases, along with other, more rare heart diseases. Accordingly, the cause of the disease lies in the genes. A genetic mutation causes the disturbances of the ion channel and thus of the heart excitation. In all ion channel diseases, the genetic mutation affects protein molecules that control the transport of ions across the cell membrane of the heart muscle. Due to the changes in these control molecules, more (gain-of-function) or less (loss-of-function) sodium and potassium ions are transported through the membranes in ion channel diseases. These processes alter the electrical properties of the heart in Brugada syndrome. In the meantime, the responsible genetic defect has been identified in a small proportion of Brugada syndrome patients. In up to 25 percent of those affected, a mutation in the SCN5A gene localized on chromosome three in gene locus 3p21 appeared to be responsible for the excitation disorder. This gene takes over the coding for control proteins of the ion channel in the DNA. Due to the mutation-related protein alteration, the molecules can only fulfill their tasks to a limited extent.

Symptoms, complaints, and signs

Patients with Brugada syndrome suffer from a repolarization disorder of the heart muscle cells. However, this repolarization disorder does not necessarily cause symptoms. A certain proportion of patients show no symptoms at all, or at least are consciously unaware of the muscle disorder. In other cases, symptoms such as sudden attacks of unconsciousness (syncope) become noticeable. Cardiac arrest may also be imminent under certain circumstances. However, all symptoms of cardiomyopathy occur after the onset of cardiac arrhythmias. The most common cardiac arrhythmias in the context of Brugada syndrome are polymorphic ventricular tachycardia and ventricular fibrillation. These cardiac disorders are due to altered repolarization properties of the myocardium. Repolarization refers to the period of time required for the heart muscle to recover after an excitation and the associated contraction. Only through repolarization can contraction take place again. In individual cases, the first symptoms of Brugada syndrome already appear in newborns. In most cases, however, they do not become apparent until the third or fourth decade of life.

Diagnosis and course

The only diagnostic signs of Brugada syndrome present with typical ECG changes. These changes correspond to a right bundle branch block-like clinical picture with abnormalities of the ST segment in leads V1 to V3. The ECG changes are only intermittently apparent. The administration of ajmaline or procainamide can enhance the symptoms.Thus, the ECG under the administration of these drugs is often the only way to make a target-oriented diagnosis. For fine diagnosis, the ECG changes are divided into three different classes. These classes have different specificity for the syndrome. Differentially, Burgada syndrome must be distinguished from diseases such as arrhythmogenic right ventricular dysplasia. The prognosis of patients depends primarily on the time of diagnosis and the age of manifestation.

Complications

Because there is no causative cure for Brugada syndrome, surgical intervention must be performed to keep the patient alive. Usually, a defibrillator is also installed in the patient’s body for this purpose. In most cases, Brugada syndrome is not noticeable to the patient, which can make diagnosis difficult. It is only through the episodes of unconsciousness that complications arise. In the worst cases, cardiac arrest can also occur during unconsciousness, resulting in death. These disorders develop when malformations and disorders of the heart develop. The affected person is thus in a life-threatening condition and suffers from so-called ventricular fibrillation. Brugada syndrome can often be observed even in babies and small children, where rapid and, above all, early treatment is possible. In order to compensate for the heart problems, it is necessary to install an automatic defibrillator, which prevents cardiac arrest. In this case, there are usually no further complications, although the patient is dependent on taking medication. Due to the cardiac arrhythmia, the affected person is also unable to perform any particular heavy tasks or sports and is thus restricted in his or her everyday life. If treatment can completely resolve the cardiac symptoms of Brugada syndrome, a decreased life expectancy is not expected.

When should you see a doctor?

If Brugada syndrome is suspected, a physician should be consulted immediately. For example, if there is a sudden loss of consciousness that cannot be attributed to any external cause, this indicates a serious condition that must be diagnosed quickly. If there are multiple cases of heart disease or heart attacks in the family, early evaluation of heart health is advisable. This is especially true if there is a history of heart arrhythmias or heart attacks. Other warning signs that should prompt immediate medical attention include sudden seizures, dizziness and other circulatory problems. In case of unconsciousness, the emergency physician must be alerted immediately. Immediate onset of respiratory arrest indicates sudden cardiac death, which can be survived only with immediate resuscitation and defibrillation. First responders should take first aid measures and perform cardiac pressure massage if the typical symptoms (dilated pupils, skin discoloration on fingernails and mucous membranes, among others) are present. If the course is positive, a prolonged stay in the hospital is subsequently required.

Treatment and therapy

Causative therapy is not available for patients with Brugada syndrome. The goal of symptomatic treatment is to prevent cardiac death. In this regard, the most important step is implantation of an automatic defibrillator. This treatment step is indicated for all patients with documented severe cardiac arrhythmias. Conservative drug therapies with beta-blockers are usually contraindicated in patients with Brugada syndrome. There is a risk of ventricular fibrillation, especially at low heart rates, which is increased by the administration of these drugs. Patients with recurrent ventricular fibrillation sometimes receive sympatomimetic medication, which temporarily suppresses symptoms. Because agents such as quinidine prolong the action potential of excitation conduction, administration of these agents may, in isolated cases, show a decrease in ECG changes. Presumably, the risk of ventricular fibrillation is also reduced by this medication. Individual trigger areas can also be electrophysiologically obliterated (ablation). This procedure has been shown in the past to eliminate arrhythmias in some patients with Brugada syndrome.

Outlook and prognosis

Brugada syndrome usually cannot be treated causally.Sufferers are therefore dependent on purely symptomatic treatment, in which the main goal is to prevent cardiac death. If no treatment is given in Brugada syndrome, the patient will die of cardiac death. For this reason, treatment involves the use of a defibrillator, which works automatically and can correct the heart’s malfunctions. However, despite treatment, the patient’s life expectancy may be significantly reduced. 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 must refrain from strenuous and physical activities in order not to strain the heart unnecessarily. In rare cases, despite the use of the defibrillator, a circulatory collapse or ventricular fibrillation may occur, requiring emergency medical treatment. Thus, the further course of Brugada syndrome is also highly dependent on the patient’s lifestyle and cannot be predicted in general.

Prevention

To date, Brugada syndrome can only be prevented by genetic counseling during the family planning phase. The genetic disorder is inherited in an autosomal dominant manner. Couples at increased risk of inheriting the condition may decide against having children of their own and consider adoption instead.

Follow-up

Follow-up care is not usually possible or necessary for Brugada syndrome. The disease cannot be treated causally because of the inherited mutation, so the affected person must rely on an automatic defibrillator. Usually, this defibrillator is surgically inserted when the syndrome is diagnosed, so the focus is on early diagnosis to avoid sudden cardiac death. Similarly, the patient is dependent on taking beta blockers to minimize the heart symptoms. The affected person should also avoid stress and unnecessary tension in order not to strain the heart unnecessarily. Regular examinations by a cardiologist are also very useful in order 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 affected person. Since Brucellosis Brugada Syndrome is a hereditary disease, the patient should undergo genetic counseling to prevent the recurrence of the syndrome. In the event of ventricular fibrillation, first aid measures must be taken, and the emergency physician should also be notified immediately. Further treatment is then provided by the emergency physician or in the hospital.

What you can do yourself

Brugada syndrome is a hereditary disease. Those affected cannot take self-help measures to treat the disease causally. However, they and their families can help prevent the worst consequence of the disorder, sudden cardiac death. Individuals whose families have already been diagnosed with Brugada syndrome should familiarize themselves with the symptoms and progression of the disease in order to consult a physician in a timely manner. Despite the need for caution, however, there is no reason to be overly concerned. Most people who suffer from Brugada syndrome do not experience any symptoms throughout their lives. Nevertheless, people should take certain symptoms seriously and have them examined promptly, especially if the syndrome has already run in the family. In many patients, cardiac arrest does not occur immediately; in most cases, other signs can be observed beforehand. These include, in particular, dizziness, seizures and loss of consciousness with no apparent cause. In these cases, a cardiac specialist should be consulted immediately so that the condition can be detected and treated before life-threatening cardiac arrhythmias occur. In the event of an acute circulatory collapse due to ventricular fibrillation, the survival of the affected person depends to a large extent on adequate first aid measures being taken immediately. If Brugada syndrome has been diagnosed and the patient shows initial symptoms, it is advisable for the social environment to undergo relevant first aid training. The employer should then also be informed so that, in the event of a collapse, the correct reaction is also taken at the workplace.