Brugada Syndrome

KEY FEATURES

ESSENTIALS OF DIAGNOSIS

• Life-threatening cardiac arrhythmia (ventricular fibrillation and ventricular tachycardia [VT]) with no demonstrable structural cardiac disease

• Brugada syndrome is defined by those who have experienced sudden cardiac death or sustained VT in patients with a Brugada pattern on 12-lead ECG

• Brugada pattern is pseudo-right bundle branch block with persistent ST elevation in V1–V2

• The disease is secondary to a sodium channel (SCN5A) mutation

• Flecainide or procainamide (sodium channel blockers) may be used to unmask the ECG changes (ST elevation in V2)

GENERAL CONSIDERATIONS

• Spontaneous or inducible polymorphic VT

• Some patients remain asymptomatic and are termed Brugada pattern. If VT or sudden death, then Brugada syndrome

• QT interval is normal

• Young males and adolescents are most often affected

• Suggested to be a cause of "sleep death" among young Asian males

• The syndrome is familial, and a mutation in chromosome 3 has been identified

CLINICAL PRESENTATION

SYMPTOMS AND SIGNS

• Cardiac arrest

• Asymptomatic

PHYSICAL EXAM FINDINGS

• Normal physical exam

DIFFERENTIAL DIAGNOSIS

• Long QT syndrome

• Idiopathic ventricular arrhythmia

• ECG changes may mimic acute myocardial infarction (cardiac enzymes and regional wall motion are usually normal but may be transiently abnormal after a cardiac arrest)

DIAGNOSTIC EVALUATION

LABORATORY TESTS

• Genetic testing in specialized labs

ELECTROCARDIOGRAPHY

• ECG with pseudo-right bundle branch block with ST elevation in V1–V2

• If the syndrome is suspected but the baseline ECG is normal, challenge with the administration of flecainide or procainamide is recommended

IMAGING STUDIES

• Echocardiogram to exclude structural heart disease

DIAGNOSTIC PROCEDURES

• Symptomatic or asymptomatic patients with abnormal ECG at baseline require electrophysiologic studies to determine whether sustained ventricular arrhythmia can be induced

TREATMENT

CARDIOLOGY REFERRAL

• All patients should be evaluated by a cardiac electrophysiologist and a medical geneticist for genetic testing

HOSPITALIZATION CRITERIA

• After a cardiac arrest, all patients are hospitalized to the cardiac intensive care unit

• Asymptomatic patients with abnormal ECG do not require hospitalization

THERAPEUTIC PROCEDURES

• Implantable cardioverter-defibrillator (ICD) is needed for patients with life-threatening arrhythmia or inducible sustained ventricular arrhythmias on electrophysiologic testing

SURGERY

• If there is no venous access, then epicardial placement of an ICD may be required

MONITORING

• ECG monitoring in hospital

DIET AND ACTIVITY

• General healthy lifestyle