DESCRIPTION 
- Right bundle branch block (RBBB) pattern and ST elevation in leads V1 and V2; three types are described:
- Type 1:
2 mm J-point elevation, coved ST elevation, negative T wave - Type 2: 2 mm J-point elevation, 1 mm saddle-type ST elevation, positive T wave
- Type 3: 2 mm J-point elevation, <1 mm saddle-type ST elevation, positive T wave
- Risk of sudden death due to polymorphic ventricular tachycardia
- 1/2 have inducible ventricular arrhythmia
- Synonym(s): None
- Sudden unexpected death in Asian immigrants (also called pokkuri in Japan, bangungot in the Philippines, and lai tai in Thailand) are related.
Pregnancy Considerations
- No contraindication to pregnancy; however, genetic counseling is recommended in view of the genetic cause and transmission of this disease.
EPIDEMIOLOGY
The incidence and prevalence are unknown. It can be recognized in patients of any age, however primarily affects young adult (80% male)
RISK FACTORS
None
ETIOLOGY
- Genetic abnormality of SCN5A and other genes in 15–20%
- Missense mutation: Channel recovers from inactivation more rapidly than normal.
- Frameshift mutation renders channel nonfunctional, which increases dispersion of refractoriness and repolarization.
Outline
Signs and symptoms:
- Asymptomatic
- Cardiac arrest
- Syncope
DIAGNOSTIC TESTS & INTERPRETATION
- EKG shows RBBB pattern and ST elevation in leads V1 and V2.
- EKG abnormalities may be unmasked by PO flecainide or IV procainamide.
- Signal-averaged EKG often shows late potentials, even in absence of r' waves in right precordial leads.
- Ventricular arrhythmias provocable by programmed stimulation at electrophysiologic study
- Endomyocardial biopsies have been done in selected cases to exclude arrhythmogenic RV dysplasia.
Lab
No test available
Imaging
- Echo to exclude cardiomyopathy
- Coronary angiography to exclude ischemia
- Ventriculography to exclude cardiomyopathy
- Cardiac MRI to exclude arrhythmogenic RV dysplasia
Diagnostic Procedures/Surgery
Electrophysiologic study: Role in diagnosis and risk stratification remains controversial
DIFFERENTIAL DIAGNOSIS
- Simple RBBB: Typically does not have ST elevation (present in Brugada syndrome), and has wide slurred S wave in V6 and lead I (not present in Brugada syndrome)
- Acute MI (because of ST elevation)
- LV aneurysm
- Myocarditis
- RV infarction
- Duchenne muscular dystrophy
- Long QT syndrome (because of polymorphic ventricular tachycardia)
- Hypercalcemia
- Hyperkalemia
Outline
ADDITIONAL TREATMENT
General Measures
- Because drug therapy is thought to be ineffective, implantation of an implantable cardioverter–defibrillator (ICD) is usually recommended in symptomatic (syncope, sudden death) patients.
- The management of asymptomatic patients remains controversial.
SURGERY
None, except implantation of an ICD
IN-PATIENT CONSIDERATIONS
Admission Criteria
- If the presentation of the Brugada syndrome is syncope or cardiac arrest, ICD implantation is usually recommended.
- If the syndrome is diagnosed incidentally, risk of disease (cardiac arrest) must be discussed.
Outline
FOLLOW-UP RECOMMENDATIONS
Patient Monitoring
- Once diagnosis is established, the patient should be seen by an electrophysiologist knowledgeable about Brugada syndrome.
- Syncope and sudden death would be indication to initiate treatment (ie, ICD).
- Avoid class I antiarrhythmic drugs that block I-Na > Ito (ie, procainamide and flecainide). Quinidine may have a protective role in selected patients.
PATIENT EDUCATION
- No intervention is known to prevent cardiac arrest. New drugs that selectively block Ito may be effective.
- Sudden death is a major risk of disease.
- Unknown if mental stress and alcohol are provocative factors
PROGNOSIS
Guarded
Outline
CODES
ICD9
- 426.4 Right bundle branch block
- 746.89 Other specified congenital anomalies of heart
SNOMED
418818005 brugada syndrome (disorder)
-blockers.