Brugada Syndrome is a rare inherited cardiac arrhythmia syndrome that is characteristed by a ‘coved-shaped’ atypical right bundle branchpattern on a 12-lead ECG (Type-1 Brugada pattern ECG) and is associated with ventricular arrhythmias and sudden cardiac death. Brugada Syndrome is reported to be responsible for 4% of all sudden deaths and 20% of sudden deaths in those without structural heart disease.
It is the leading inherited cardiac cause of sudden death in subjects under 40 years. However, a family history is present in only about 20-30% of patients. The ECG changes of Brugada Syndrome are dynamic and can vary spontaneously making it difficult to assess its exact incidence in the general population but it’s prevalence is reported to be about 1 in 2000.
Many people who have Brugada Syndrome don’t have any symptoms, and so they’re unaware of their condition. For some, however, Brugada syndrome can cause dangerous irregular heart rhythms that can cause fainting or sudden cardiac arrest. The abnormal Brugada ECG pattern can be induced by a variety of cardiac and non-cardiac medications so avoidance of these medications is paramount to the treatment of this disease.
Treatment of Brugada Syndrome is involves a combination of preventive measures such as avoiding aggravating medications, reducing fever and sometimes when necessary, using a medical device called an implantable cardioverter-defibrillator (ICD).
Patients with Brugada Syndrome may present with syncope due to dangerous heart rhythms from the bottom chamber of the heart (Polymorphic Ventricular Tachycardia or and Ventricular Fibrillation) or resuscitated sudden death in the third or fourth decade of life. Symptoms typically occur at night, or at rest during the day, and are due to polymorphic VT or ventricular fibrillation (VF). Many people who have Brugada Syndrome are undiagnosed because the condition often hasn’t caused any noticeable signs or symptoms.
The diagnosis of Brugada Syndrome may also be made on family screening of patients with Brugada Syndrome or from a routine ECG. More than 80% of adult patients are males but in children there is an equal male to female ratio. Clinical presentation is predominantly after adolescence with a peak in the third and fourth decade of life. In cases of sudden cardiac deaths Brugada Syndrome may be under-diagnosed as ECG prior to death is generally not available and even if an ECG has been recorded ECG changes, being variable, may not be diagnostic.
The most important sign is the presence of the diagnostic Type-1 Brugada pattern on an electrocardiogram, or ECG. Pattern, only detected on an ECG. Only Type 1 ECG pattern is diagnostic of Brugada Syndrome. Type 2 and 3 patterns are not diagnostic of Brugada Syndrome and distinction from a normal variant can be difficult and pharmacological provocation test may be required if the diagnosis of Brugada Syndrome is suspected.
It’s possible to have a Brugada pattern ECG without having Brugada Syndrome. However, signs and symptoms that could mean you may have Brugada Syndrome include:
Brugada syndrome is a heart rhythm disorder. Each beat of the heart is triggered by an electrical impulse generated by special cells in the right upper chamber of your heart. Tiny pores, called channels, on each of these cells direct this electrical activity, which makes your heart beat. In Brugada syndrome, a defect in these channels can cause the heart to beat abnormally. The most common defect is an abnormality in a cardiac sodium channel.
Brugada Syndrome is usually inherited, but it may also result from a structural abnormality in the heart, imbalances in chemicals that help transmit electrical signals through the body (electrolytes), or the effects of certain prescription medications or cocaine use. Brugada syndrome is usually diagnosed in adolescents and adults. It may be diagnosed in young children where it is frequently precipitated by fever.
Associated risk factors for Brugada Syndrome include:
The most serious complication of Brugada syndrome is sudden cardiac arrest. Sudden cardiac arrest is the sudden, unexpected loss of heart function, breathing and consciousness. It’s a medical emergency. If not treated immediately, the condition is fatal, resulting in sudden cardiac death. With fast, appropriate medical care, survival is possible. Administering cardiopulmonary resuscitation (CPR) — or even just rapid compressions to the chest — can improve the chances of survival until emergency personnel arrive.
Sudden fainting (syncope) is another complication of Brugada syndrome. If you have Brugada syndrome and you faint, seek emergency medical attention.
Aside from a typical physical examination and listening to your heart with a stethoscope, tests to see if you have Brugada Syndrome may include:
The diagnosis of Brugada Syndrome can only be considered when a diagnostic Type-1 Brugada pattern ECG occurs spontaneously or following drug provocation. The diagnosis is further confirmed when the ECG pattern occurs in conjunction with one of the following:
Treatment of Brugada Syndrome depends on the risk of an abnormal heartbeat (arrhythmia) for that particular individual. Those considered at high risk have:
Implantable cardioverter-defibrillator (ICD).For high-risk individuals and symptomatic Brugada Syndrome patients, treatment may involve an Implantable Cardioverter-Defibrillator (ICD). An ICD is a small device continuously monitors your heart rhythm and delivers electrical shocks when needed to control abnormal heartbeats. The guidelines recommends ICD implantation in Brugada Syndrome patients who have survived cardiac arrest or have a history of syncope and documented ventricular arrhythmias.
There’s a small risk of complications from having an ICD implanted. People who have an ICD implanted as a treatment for Brugada syndrome have reported receiving shocks from their ICD even when their heartbeat was regular. These are called inappropriate shocks. This may be because many people who receive an ICD as a treatment for Brugada Syndrome are young, and may receive shocks when their heart rates increase during normal stresses, such as exercise.
Sometimes an inappropriate shock is delivered for another fast heart rhythm such as Atrial Fibrillation or an unrelated heart rhythm problem such as Supraventricular Tachycardia (SVT). Atrial Fibrillation occurs in about 20% of patients with Brugada Syndrome. Your doctor will program your ICD to reduce this risk. If you have an ICD implanted as part of your Brugada syndrome treatment, talk to your doctor about ways to avoid inappropriate shocks.
A drug called Quinidine is used in Brugada Syndrome patients who have repeated ICD shocks or an ‘arrhythmic storm’ . Intravenous Isoprenaline (a form of adrenaline) is also helpful in the emergency treatment of arrhythmic storms in Brugada Syndrome.
As the changes of Brugada Syndrome on ECG are unmasked by a febrile states, aggressive treatment of all febrile episodes is recommended with antipyretics like aspirin and paracetamol and cold sponges. Hypokalemia, large carbohydrate meals and alcohol and very hot baths have also been incriminated and should be avoided.
Drugs that can cause Brugada-like changes on the ECG are best avoided and include: Class 1antiarrhythmic drugs like flecainide, beta and alpha adrenergic blockers, channel blockers like verapamil, diltiazem, nifedipine, nitrates, potassium channel openers like nicorandil, tricyclic and tetracyclic antidepressants, phenothiazines and antidepressants like fluoxetine. Alcohol and cocaine can cause dangerous heart rhythms in patients with Brugada Syndrome. A website www.brugadadrugs.org gives a list of drugs to be avoided, preferably avoided and potential antiarrhythmic drugs in Brugada Syndrome.
Continued medical checkups. If you have Brugada syndrome, it’s a good idea to regularly check in with your doctor to make sure you’re properly managing your heart condition. Regular checkups can help your doctor decide if you need to change your treatment, and may help catch new problems early, if they occur.