Merck Manual

Please confirm that you are a health care professional

honeypot link

Brugada Syndrome

By

L. Brent Mitchell

, MD, Libin Cardiovascular Institute of Alberta, University of Calgary

Last full review/revision Jan 2021
Click here for Patient Education
Topic Resources

Brugada syndrome is an inherited disorder of cardiac electrophysiology causing an increased risk of syncope and sudden death.

Several different mutations are involved, most affecting the SCN5A gene that encodes the alpha-subunit of the voltage-dependent cardiac sodium channel. Typically, patients have no structural heart disease. Nevertheless, relationships with other genetic and acquired structural heart diseases are increasingly being recognized, as are overlap syndromes with long QT syndrome type 3 Congenital long QT syndrome Torsades de pointes is a specific form of polymorphic ventricular tachycardia in patients with a long QT interval. It is characterized by rapid, irregular QRS complexes, which appear to be twisting... read more and with arrhythmogenic right ventricular dysplasia (ARVD).

In some patients, Brugada syndrome has no clinical expression. However, in many patients it leads to syncope or sudden cardiac death due to polymorphic ventricular tachycardia Ventricular Tachycardia (VT) Ventricular tachycardia is ≥ 3 consecutive ventricular beats at a rate ≥ 120 beats/minute. Symptoms depend on duration and vary from none to palpitations to hemodynamic collapse and death. Diagnosis... read more and ventricular fibrillation Ventricular Fibrillation (VF) Ventricular fibrillation causes uncoordinated quivering of the ventricle with no useful contractions. It causes immediate syncope and death within minutes. Treatment is with cardiopulmonary... read more Ventricular Fibrillation (VF) . Events occur more often at night and are not usually related to exercise. Events may also be brought on by fever and by certain drugs, including sodium channel blockers, beta-blockers, tricyclic antidepressants, lithium, and cocaine.

Diagnosis of Brugada Syndrome

  • Electrocardiography (ECG)

  • Family history

Diagnosis should be considered in patients with unexplained cardiac arrest or syncope or a family history of such. Role of electrophysiologic testing is currently unclear.

Initial diagnosis of Brugada syndrome is based on a characteristic ECG pattern, the type 1 Brugada ECG pattern (see figure Type 1 Brugada ECG pattern Type 1 Brugada ECG pattern Brugada syndrome is an inherited disorder of cardiac electrophysiology causing an increased risk of syncope and sudden death. (See also Overview of Arrhythmias.) Several different mutations... read more ). The type 1 Brugada ECG pattern has prominent ST elevation in V1 and V2 (sometimes involving V3) that causes the QRS complex in these leads to resemble right bundle branch block Bundle Branch Block and Fascicular Block Bundle branch block is partial or complete interruption of impulse conduction in a bundle branch; fascicular block is similar interruption in a hemifascicle of the bundle. The 2 disorders often... read more . The ST segment is coved and descends to an inverted T-wave. Lesser degrees of these patterns (type 2 and type 3 Brugada ECG patterns) are not considered diagnostic. The type 2 and type 3 patterns may change to a type 1 pattern spontaneously, with fever, or in response to drugs. The latter is the basis of a challenge diagnostic test usually using ajmaline or procainamide.

Type 1 Brugada ECG pattern

Prominent J-point elevation to a coved ST segment, leading to an inverted T-wave in leads V1 and V2.

Type 1 Brugada ECG pattern

Treatment of Brugada Syndrome

  • Implantable cardioverter-defibrillator

Best treatment of Brugada syndrome in patients diagnosed based on ECG changes and family history is unclear, although they do have increased risk of sudden death.

Click here for Patient Education
NOTE: This is the Professional Version. CONSUMERS: Click here for the Consumer Version
Professionals also read
Test your knowledge
Angina Pectoris
Angina pectoris is usually described as chest discomfort rather than as chest “pain.” The symptoms of angina pectoris may be a vague, barely troublesome ache or may rapidly become a severe, intense precordial crushing sensation. Although the location of the discomfort varies, it is most commonly felt at which of the following locations?
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID

Also of Interest

Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
TOP