Brugada syndrome

By Mayo Clinic Staff

Brugada (brew-GAH-dah) syndrome is a rare heart rhythm condition. It can cause the heart to beat very fast and in an uneven way. These irregular heartbeats are called arrhythmias. Brugada syndrome usually runs in families, which means it's inherited. It's often linked to changes in genes.

People with Brugada syndrome have a higher risk of a dangerously fast and uneven heartbeat called ventricular fibrillation (VFib). VFib is a medical emergency. It needs treatment right away. Without treatment, it can cause sudden cardiac death.

Treatment for Brugada syndrome depends on your risk of serious irregular heartbeats such as VFib. Some people without symptoms of Brugada syndrome may not need treatment. Others may need medicines, a heart procedure or a device called an implantable cardioverter-defibrillator (ICD).

If you have Brugada syndrome, you need to stay away from things that can trigger irregular heartbeats. For example, it's important to quickly lower a fever and not use some medicines.

Many people with Brugada syndrome have no symptoms. When symptoms occur, they may be related to a dangerously fast heartbeat.

Symptoms of Brugada syndrome may include:

• Fainting.
• Fast, fluttering or pounding heartbeats, called palpitations.
• Gasping or difficult breathing during sleep.
• Seizures.

If you have symptoms of Brugada syndrome, you may be referred to a heart rhythm specialist.

Make an appointment with a healthcare professional if you have fainting, palpitations or other symptoms that could be related to a heart rhythm condition. Testing can help find the cause.

Talk with your healthcare team if a parent, sibling or child has Brugada syndrome. You may need testing even if you don't have symptoms.

Call 911 or your local emergency number if you faint and may be having a dangerous heartbeat. Get emergency help for sudden cardiac arrest or symptoms of a life-threatening heartbeat.

The heart's electrical system controls the heartbeat. The heart's electrical signals tell the heart when to squeeze and relax so it can pump blood. The signals start in a group of cells at the top of the heart called the sinus node. They travel through a pathway between the upper and lower heart chambers called the atrioventricular (AV) node. The timing of the signals is what creates a steady heartbeat and lets the heart pump blood.

In a healthy heart, this signaling process usually goes smoothly. But in Brugada syndrome, changes in the heart's electrical signals can lead to dangerous heartbeats in the heart's lower chambers. An example is ventricular fibrillation (VFib). Without treatment right away, VFib can cause sudden cardiac arrest or sudden cardiac death.

Brugada syndrome is linked to changes in genes. The condition can be passed down in families, but the way it is inherited is complex. Changes in a gene called SCN5A are the best-known genetic cause of Brugada syndrome.

In many people with Brugada syndrome, genetic testing doesn't find a disease-causing change in the SCN5A gene. This type of gene change is found in about 20% to 25% of people with Brugada syndrome.

Some medicines can cause changes on a test called an electrocardiogram (ECG or EKG) that can look like Brugada syndrome. An ECG records the electrical signals that make the heart beat. The results appear as lines and waves called a tracing. The shape of the tracing gives your healthcare team information about the heart's electrical activity. Medicines called sodium channel blockers can cause a type 1 Brugada pattern to appear. In a type 1 pattern, part of the ECG tracing rises and then slopes down in a curved shape.

If medicine causes a type 1 pattern, your healthcare team looks at the pattern along with symptoms, family history and other information when diagnosing Brugada syndrome.

Some antidepressants also may cause Brugada pattern changes.

Risk factors for Brugada syndrome include:

Family history of Brugada syndrome. Brugada syndrome can be passed down in families. Having a close family member with Brugada syndrome may raise your risk of having the condition.

Being male. Brugada syndrome is more common in males than in females.

Asian background. Brugada syndrome is more common in people with an Asian background.

Fever. A fever doesn't cause Brugada syndrome. But it can affect the heart and trigger an irregular heartbeat that can cause fainting or sudden cardiac arrest in people with Brugada syndrome.

Some medicines. Some medicines can cause a type 1 Brugada pattern or trigger ventricular fibrillation. Ask your healthcare team which medicines to avoid. Always tell your healthcare team about all the medicines you take. Include those you buy without a prescription.

Alcohol use. Drinking a lot of alcohol can trigger ventricular fibrillation and sudden cardiac arrest in some people with Brugada syndrome.

Cannabis and cocaine use. Cannabis and cocaine may cause changes on an ECG that look like Brugada syndrome. Tetrahydrocannabinol (THC), the main mind-altering ingredient in cannabis, also may trigger dangerous heartbeats in people with Brugada syndrome.

Complications of Brugada syndrome include:

Ventricular fibrillation. This is a dangerously fast and uneven heartbeat that can cause sudden cardiac arrest. VFib needs emergency medical care. If you have Brugada syndrome and faint, get medical help right away. Fainting can be a symptom of VFib.

Sudden cardiac arrest. This is the sudden loss of heart function, breathing and consciousness. Emergency treatment is needed right away to prevent sudden cardiac death.

If you have Brugada syndrome, taking steps to avoid certain triggers can help lower your risk of dangerous heartbeats.

If someone in your family has Brugada syndrome, talk with your healthcare team about genetic testing. Genetic testing can help you learn if you have a gene change linked to Brugada syndrome.

To diagnose Brugada syndrome, your healthcare team examines you and listens to your heart with a tool called a stethoscope. Brugada syndrome may be found when a test called an electrocardiogram (ECG or EKG) is done for other reasons.

Your healthcare professional does tests to diagnose Brugada syndrome. Tests also help your healthcare professional look for other conditions that may seem like Brugada syndrome.

This test measures the electrical activity of the heart. It can show how the heart is beating. may be done with or without medicine. During an ECG, sticky patches with sensors on them go on the chest and sometimes the arms and legs. Wires connect the sensors to a machine, which shows or prints the results. The electrical signals in the heart show up as lines and waves, called a tracing. The shape of the tracing shows how the heart's electrical activity is working.

Your healthcare professional looks at the signal patterns in the ECG results to learn whether there is a change in your heartbeat. You may hear the term "Brugada pattern," which describes certain changes seen on an ECG. A main sign of Brugada syndrome is a type 1 Brugada pattern on an ECG. The pattern can come and go, so it may not appear on every ECG. Having a Brugada pattern does not always mean that you have Brugada syndrome. Your healthcare team considers your ECG results along with symptoms, family history and other information when making a diagnosis.

• A type 1 Brugada pattern has a rise in part of the ECG tracing called the ST segment. The line then slopes down in a curved shape. It ends with a T wave that points down.
• A type 2 Brugada pattern rises, dips and rises again. A type 2 pattern may be a sign of Brugada syndrome, but this pattern alone does not mean you have the condition.
• A type 3 Brugada pattern has a smaller change in the ST segment than the other Brugada patterns. This pattern alone does not mean you have Brugada syndrome. Today, type 2 and type 3 patterns are considered older terms. These patterns may be grouped together as patterns that need more testing.

Brugada syndrome can have some features in common with other heart conditions. An ECG can help look for these other conditions. For example, long QT syndrome also causes dangerous heartbeats, but it causes different changes on an ECG.

Wellens syndrome also causes different ECG changes. Unlike Brugada syndrome, Wellens syndrome is related to severely reduced blood flow through a coronary artery and can be a warning sign of a heart attack. Your healthcare team uses your ECG and other information to find out which condition you may have.

Sometimes a regular ECG doesn't show an irregular heartbeat. You may need other types of ECG tests.

• Sodium channel blocker test. This test may be done if a regular ECG doesn't show a type 1 Brugada pattern but your healthcare team still thinks you may have Brugada syndrome. You get medicine through a needle in a vein and then an ECG is done. The medicine may cause a Type 1 Brugada pattern on the ECG.

  A positive result does not always mean you have Brugada syndrome. Your healthcare team considers your symptoms, family history and other information when deciding what the result means.

• Holter monitor. This is a small heart monitor that you wear for a day or more during your regular activities. Because a Brugada pattern can come and go, longer heart monitoring may find a type 1 pattern that was not seen on a regular ECG.

Other tests may be done to look for changes in the heart that might explain your symptoms or test results.

• Echocardiogram. This test uses sound waves to make pictures of the heart. It shows how blood flows through the heart and heart valves. An echocardiogram can't diagnose Brugada syndrome. But it can help find changes with the structure of the heart.
• Electrophysiological (EP) study. An EP study checks the heart's electrical activity. It may help your healthcare team understand your risk of dangerous heartbeats and guide treatment in some cases.
• During this test, a doctor places thin tubes called catheters into a blood vessel, usually in the groin. The catheters are guided into the heart. Special catheters record the heart's electrical signals.
• Cardiac MRI. This imaging test makes detailed pictures of the heart. Your healthcare team may use this test to look for another heart condition when your test results suggest one might be present.

Brugada syndrome may be passed down in families. If your healthcare team thinks you may have Brugada syndrome, genetic testing may be recommended. Genetic testing can help you learn if you have a gene change linked to Brugada syndrome.

If your test is positive, meaning you have a gene for Brugada, your first-degree relatives may need an electrocardiogram to check for signs of Brugada syndrome. First-degree relatives include parents, siblings and children. Your healthcare team gives you instructions about family screening.

Treatment for Brugada syndrome depends on your risk of dangerously fast heartbeats, including ventricular fibrillation.

If you have Brugada syndrome but no symptoms, you may not need treatment. Your risk of a dangerous heartbeat may be low.

Your healthcare team may tell you that you're at high risk of dangerously fast heartbeats and need treatment for Brugada syndrome if you:

• Have a history of a serious irregular heartbeat in the lower chambers of the heart, called the ventricles.
• Fainted because of an irregular heartbeat that started in the ventricles.
• Survived sudden cardiac arrest.
• Brugada treatment for those at high risk of dangerously fast heartbeats, including ventricular fibrillation, may include:

• Medicines.
• A heart procedure called cardiac ablation to treat irregular heartbeats.
• A medical device called an implantable cardioverter-defibrillator (ICD).

Preventing dangerous heartbeat changes also is an important part of treatment. People with Brugada syndrome should stay away from things that can trigger dangerous heartbeat changes, including some medicines.

Your healthcare team talks with you about your risk and which treatment may be right for you.

Some people with Brugada syndrome are prescribed medicines, such as quinidine, to prevent a potentially dangerous heartbeat. These medicines may be prescribed alone or with a medical device called an implantable cardioverter-defibrillator (ICD) that controls the heartbeat.

If you have Brugada syndrome and a fever, take medicine to lower the fever.

People with Brugada syndrome who've had sudden cardiac arrest or fainting caused by an irregular heartbeat may need a procedure or a medical device to treat dangerous heartbeats.

• Implantable cardioverter-defibrillator (ICD). An ICD may be used in people at high risk of sudden cardiac death. The ICD continually checks your heartbeat. If it finds a life-threatening irregular heartbeat, it can deliver a shock to reset the heart's rhythm.

  Cardiac ablation. If you continue to have dangerous heartbeats or repeated ICD shocks, you may have this treatment. For irregular heartbeats related to Brugada syndrome, radiofrequency cardiac ablation uses heat to treat small areas of heart tissue that are causing faulty electrical signals and dangerous heartbeats.

You may get medicine to help prevent pain or help you relax during these procedures. Tell your healthcare team that you have Brugada syndrome before any treatment that involves anesthesia or sedation. Your healthcare team considers your condition when planning your care.

If you have Brugada syndrome, you need regular follow-up with your healthcare team. Your healthcare team can monitor your condition and decide whether your treatment or follow-up plan needs to change.

There isn't one life expectancy estimate that applies to everyone with Brugada syndrome. Many people without symptoms or whose test results show a lower risk of dangerous heartbeats may have a long life expectancy. People who have survived sudden cardiac arrest or have fainted because of a dangerous heartbeat have a higher risk of serious heart rhythm changes.

Your healthcare team uses your symptoms, electrocardiogram findings and other test results to estimate your risk of dangerous heartbeats and sudden cardiac death. For people at higher risk of sudden cardiac death, a heart device called an ICD may lower that risk.

If you have Brugada syndrome, your healthcare team may tell you to take steps to lower your risk of dangerous irregular heartbeats.

• Treat a fever with medicine right away. Fever can cause Brugada electrocardiogram (ECG) pattern and trigger dangerous irregular heartbeats. Use fever-lowering medicine right away.
• Do not take medicines that may trigger an irregular heartbeat. Many medicines can raise this risk, including certain medicines used to treat depression and some medicines used to treat irregular heartbeats. Ask your healthcare team which medicines to avoid. Tell your healthcare team about all the medicines, vitamins and supplements you take, including those you buy without a prescription.
• Tell your healthcare team before surgery or anesthesia. Some medicines used during anesthesia and other factors related to surgery, such as fever or a very slow heartbeat, may affect the heartbeat in people with Brugada syndrome. Your anesthesia team can consider these risks when planning your care.
• Talk with your healthcare team about alcohol use. Alcohol can raise the risk of irregular heartbeats. Ask your healthcare team what amount of alcohol, if any, is safe for you.
• Avoid cocaine and cannabis. Cocaine and cannabis may cause Brugada ECG pattern in some people. Tetrahydrocannabinol (THC), the main mind-altering ingredient in cannabis, also may trigger dangerous heartbeats in people with Brugada syndrome.
• Ask about competitive sports. If you have Brugada syndrome or if you have an implantable cardioverter-defibrillator (ICD), ask your healthcare team which sports activities are safe for you. Some people with Brugada syndrome may be able to play competitive sports after being evaluated by an expert. Some contact or impact sports may pose a risk of damage to the ICD system. Talk with your healthcare team about the risks and benefits of the sports you want to play.

Finding out you have Brugada syndrome can bring questions or concerns. You may worry about whether your treatment will work or whether other family members could be at risk.

Getting support from friends and family may be helpful. If you need more help, ask your healthcare team if there are any support groups in your area. Connecting with others in a support group may help lower stress related to Brugada syndrome.

You may need more than one visit or test to find out whether you have Brugada syndrome. The pattern on the electrocardiogram can come and go.

If you do have Brugada syndrome, you may need more tests to learn about your risk of dangerous heartbeats. Your healthcare team usually gives you instructions to help you get ready for each visit.

Here's some information to help you get ready for your first appointment.

• Ask if there's anything you need to do before your appointment. For example, you may be asked not to eat or drink for a while before some tests. This is called fasting.
• Write down your symptoms. Include any symptoms that don't seem related to Brugada syndrome. Also note when the symptoms started.
• Write down important personal information, especially any family history of sudden death, cardiac arrest or heart conditions. Also include any personal history of fainting or irregular heartbeats.
• Make a list of all medicines, vitamins and supplements you take. Include those bought without a prescription. Also include the doses.
• Take someone with you to your appointment if you can. Someone who joins you may remember something that you missed or forgot.
• Write down questions for your healthcare team.

For Brugada syndrome, some basic questions to ask your healthcare team are:

• What's the most likely cause of my symptoms?
• What tests do I need?
• What types of treatments are available for Brugada syndrome? Which do you recommend for me?
• What level of physical activity is right for me?
• Do I need to change my diet?
• How often do I need health checkups?
• I have other health conditions. How can I best manage these conditions together?
• What should I tell an anesthesiologist before surgery or another procedure?
• Do members of my family need testing for Brugada syndrome?
• Is there any printed information that I can take home with me? What websites do you recommend?

Don't hesitate to ask any other questions you have.

Your healthcare team is likely to ask you questions such as:

• Do you always have symptoms or do they come and go?
• How often do you have symptoms such as fainting?
• What, if anything, makes your symptoms better?
• What, if anything, makes your symptoms worse?
• Do you have a family history of irregular heartbeats, sudden cardiac death or other heart disease?

Your answers help your healthcare team learn more about your symptoms and plan your care.

Mayo Clinic researchers are working to better understand the genetic, electrical and structural causes of Brugada syndrome. Through the Sudden Death Genomics Laboratory and Cardiovascular Research Center, investigators are studying disease-causing genes, identifying new risk factors, improving diagnostic testing and exploring evidence that Brugada syndrome may involve both electrical irregularities and structural changes in the heart. This work aims to improve early detection, more accurately predict who is at risk of life-threatening arrhythmias, and develop more personalized approaches to treatment and prevention.

See a list of publications about Brugada syndrome by Mayo Clinic doctors on PubMed, a service of the National Library of Medicine.