--- title: Brugada syndrome description: What Brugada syndrome is, why it runs in families, how it is detected on the ECG, which treatment approaches clinical guidelines describe and when urgent help is needed. type: disease preset: brugada-syndrome aliases: - BrS sources: - tier: guideline org: minzdrav-rf title: Желудочковые нарушения ритма сердца. Внезапная сердечная смерть year: 2025 doi: 10.15829/1560-4071-2025-6670 url: https://cr.minzdrav.gov.ru/view-cr/569_2 - tier: reference org: msd-manuals title: Brugada Syndrome year: 2026 url: https://www.msdmanuals.com/professional/cardiovascular-disorders/arrhythmogenic-cardiac-disorders/brugada-syndrome - tier: guideline org: nice title: Transient loss of consciousness ('blackouts') in over 16s (CG109) year: 2023 url: https://www.nice.org.uk/guidance/cg109 - tier: guideline org: nice title: Implantable cardioverter defibrillators and cardiac resynchronisation therapy for arrhythmias and heart failure (TA314) year: 2014 url: https://www.nice.org.uk/guidance/ta314 sources_checked: 2026-10-12 review: null --- Brugada syndrome is an inherited channelopathy (a disorder of the ion channels of heart cells) with a typical pattern on the [ECG](../../diagnostic/ecg/) and a high risk of ventricular fibrillation and sudden cardiac death. Typically, there is no clinical evidence of structural heart disease. The danger of the syndrome is [ventricular tachycardia](../ventricular-tachycardia/) and ventricular fibrillation, which lead to fainting and sudden death. According to the MSD Manual, Brugada syndrome affects about 5 in 10,000 people, with wide variation between ethnic groups and regions.

V1 and V2 are the right precordial ECG leads; their electrodes are usually placed in the fourth intercostal space. For comparison, the diagram shows a complex without J-point or ST elevation: after the QRS complex the ST segment runs along the baseline.

In the type 1 pattern the J point and the ST segment in V1 and V2 are clearly raised, so the QRS complex resembles right bundle branch block; the ST segment is coved and descends to an inverted T wave. The Russian Ministry of Health guideline makes the diagnosis when ST elevation of this shape is 2 mm or more in at least one of leads V1–V2, either spontaneously or after a provocative drug test. The pattern may be more evident when the V1 and V2 electrodes are placed one or two intercostal spaces higher than usual. The dashed line shows the usual ST segment and T wave for comparison.

## Why it happens Brugada syndrome is inherited in a dominant way, but not everyone who carries it shows signs of it: this depends on age and sex. It shows itself more often in adults, and 8 times more often in men than in women. Changes (mutations) in genes disturb the ion channels through which charged particles move into and out of heart cells. This affects the electrical activity of the cells in the outflow tract of the right ventricle most, and the heart becomes prone to dangerous arrhythmias. An attack can be brought on by fever, certain medicines, cocaine and large amounts of alcohol. Brugada syndrome is a channelopathy with dominant inheritance and variable penetrance that depends on age and sex. The mutations decrease inward sodium or calcium currents or increase early outward potassium currents; this leads to early loss of the action potential plateau, particularly in the epicardial cells of the right ventricular outflow tract, which produces the characteristic right precordial ECG changes and a propensity to ventricular tachyarrhythmias. SCN5A is the only gene with proven causality, but mutations in it account for only about 20% of cases. Typically there is no clinical evidence of structural heart disease, although most patients have microscopic structural abnormalities in the epicardium of the right ventricular outflow tract. The Russian Ministry of Health guideline lists psychotropic drugs, some antiarrhythmic drugs, anaesthetics, cocaine, excessive alcohol and fever as potential triggers of the type 1 pattern and of ventricular fibrillation. Class IA and IC antiarrhythmic drugs and some other sodium channel blockers increase the risk of ventricular arrhythmias. The MSD Manual also names beta-blockers, certain antidepressants and antipsychotics among the medicines that can bring on events. ## Symptoms Most people with Brugada syndrome have no symptoms. In some of them a ventricular arrhythmia causes fainting or sudden cardiac arrest. Such events happen more often at night, at rest or during sleep, and are not usually related to exercise. A dangerous arrhythmia most often first appears at around 40, but it can happen at any age. It can be brought on by a high temperature. Most patients diagnosed with Brugada syndrome are asymptomatic; some develop syncope or sudden cardiac death due to polymorphic ventricular tachycardia and ventricular fibrillation, including during sleep. About 10–20% of patients develop atrial tachyarrhythmias, predominantly [atrial fibrillation](../atrial-fibrillation/), and in some it is the first clinical manifestation of the disease. ## How it is diagnosed Doctors consider Brugada syndrome when a person without structural heart disease has had an unexplained cardiac arrest or fainting, or when there have been such events in the family. The main test is an ECG: the doctor looks for the typical pattern in the right precordial leads V1 and V2, sometimes recording them one or two intercostal spaces higher than usual. The typical pattern is not always visible: it may appear with fever or in response to medicines. This is the basis of the provocative test: a drug that blocks sodium channels is given into a vein, and doctors watch whether the type 1 pattern appears on the ECG. Similar ECG changes occur with myocardial ischaemia, electrolyte disturbances, [pulmonary embolism](../pulmonary-embolism/) and drug toxicity, so the doctor rules these causes out. Genetic testing is recommended when the ECG shows the type 1 pattern and there has also been fainting, cardiac arrest or similar events in the family; a causative mutation is found in only about 20% of cases. Because the syndrome is inherited, family members are checked too. If a significant mutation is found in a person, relatives are tested for it. If a relative died suddenly and the post-mortem found no cause, close relatives are advised to see a cardiologist; the check-up includes an ECG with the V1–V2 electrodes placed higher than usual. Under the Russian guideline, Brugada syndrome is diagnosed with type 1 ST-segment elevation ≥ 2 mm in one or more right precordial leads V1 and/or V2 positioned in the second, third or fourth intercostal space, occurring either spontaneously or after a provocative test with an intravenous antiarrhythmic drug. Type 2 and type 3 patterns are not considered diagnostic; they may change to a type 1 pattern spontaneously, with fever or in response to medications. The MSD Manual describes a different approach: under the Shanghai Brugada syndrome score only a spontaneous type 1 pattern is considered diagnostic, and clinical, family history and genetic criteria are applied to establish the diagnosis. A pharmacological test with sodium channel blockers (class IA and IC antiarrhythmic drugs) is recommended for survivors of sudden cardiac arrest without an obvious cause (ESC IB) and for relatives of people who died of sudden arrhythmic death, aged 16 years and older, if their initial evaluation or the proband's findings raise suspicion of Brugada syndrome (ESC IIaB). Testing for SCN5A mutations is recommended for a type 1 pattern, spontaneous or with sodium channel blockers, combined with clinical manifestations and/or a positive family history; variant-specific cascade family screening is recommended for family members of a proband with a rare class IV–V pathogenic variant. An electrophysiological study is recommended for risk stratification in adults, but its results should be interpreted with caution: absence of inducible VT or VF points to a favourable prognosis, while the prognostic value of induction has not been established. ## How it is treated The Russian Ministry of Health guideline advises everyone with Brugada syndrome to avoid medicines that can bring on ST elevation, not to use cocaine or cannabis, not to drink large amounts of alcohol, and to take steps straight away to bring down a fever of any cause. A list of such medicines is available at brugadadrugs.org, which the Russian guideline refers to. If a medicine may increase the risk, the doctor stops it where possible and prescribes an alternative. An implantable cardioverter-defibrillator (ICD) is used to protect against sudden death. It is recommended for people who have survived cardiac arrest or had sustained ventricular tachycardia, and for people with a spontaneous (appearing without a drug test) type 1 ECG pattern and fainting that is probably caused by an arrhythmia. For people without symptoms the best approach is unclear, although their risk of sudden death is increased; scoring systems have been developed to help decide whether an ICD is needed. If ICD shocks keep recurring, specialists may add medicines and, if these do not help, perform catheter ablation: treatment of the area of the heart that triggers the arrhythmia. Lifestyle measures are recommended for all patients with Brugada syndrome: avoid drugs that may induce ST-segment elevation in the right precordial leads (list at www.brugadadrugs.org), avoid cocaine, cannabis and excessive alcohol, and treat fever of any cause with antipyretic measures immediately (ESC IC). ICD implantation is recommended for patients who survived cardiac arrest and/or have documented spontaneous sustained VT (ESC IC), and for patients with a spontaneous type 1 pattern and a history of syncope probably of arrhythmic origin (ESC IIaC); it may be considered if VF is induced by programmed ventricular stimulation with up to two extrastimuli (ESC IIbC). NICE lists Brugada syndrome among familial cardiac conditions with a high risk of sudden death for which ICDs are recommended as a treatment option. Catheter ablation of the ventricular ectopic beats that trigger VF/VT and/or of the epicardial substrate of the right ventricular outflow tract is recommended for recurrent ICD shocks refractory to drug therapy (ESC IIaC). The MSD Manual also suggests drug therapy when frequent ICD discharges need to be suppressed or when the patient declines an ICD. ## When to call an ambulance In Brugada syndrome, polymorphic ventricular tachycardia and ventricular fibrillation can cause fainting and sudden death, including during sleep. The Russian Ministry of Health guideline advises calling an ambulance if an episode of arrhythmia comes with dizziness, weakness, feeling faint, loss of consciousness or a racing heartbeat, and also for any episode of feeling faint or losing consciousness. An ambulance is also called when an implanted cardioverter-defibrillator has gone off. Call your local emergency number (112 in the EU, 911 in the US and Canada, 999 in the UK). Even if the person has come round, NICE (for people over 16) treats the following as red flags after a blackout: an ECG abnormality (including any ST segment or T wave abnormality and signs of Brugada syndrome), a blackout during exertion, and a family history of sudden cardiac death in people younger than 40 or of an inherited heart condition. Such a person is referred urgently for cardiovascular assessment, and a specialist reviews the referral within 24 hours.