Brugada’s Syndrome and Sudden Cardiac Death

Petra Lovrec

Brugada’s Syndrome and Sudden Cardiac Death

Petra LovrecMentor: A. Žmegač Horvat

Sudden Cardiac Death

Incidence

(cases/year)

Survival

Worldwide 3 000 000 ‹1%

U.S. 450 000 5%

W. Europe 400 000 ‹5%

Causes of Sudden Cardiac Death

• 80% - coronary artery disease

• 15% - cardiomyopathy

• 5% - other

Cardiomyopathy

• dilated cardiomyopathy

• hypertrophic cardiomyopathy

• arrythmogenic right ventricular cardiomyopathy

• left ventricular non-compaction

• restrictive cardiomyopathy

Cardiac Chanellopathies

• Brugada syndrome

• long QT syndrome

• short QT syndrome

• idiopathic VF

• short coupled Torsades

Brugada Syndrome

• first described in 1992 in 8 patients with aborted sudden cardiac death

• history since 1986 – Brugada brothers

Brugada Syndrome

• characterized by:– ECG findings of RBBB and persistent ST

elevation in V1 – V3– structurally normal hearts– propensity for life-threatening ventricular

arrhythmias– J point elevation

Brugada Syndrome: ECG

Brugada Syndrome: ECG

Typical electrocardiogram of Brugada syndrome. Note the pattern resembling a right bundle branch block,the P-R prolongation and the ST elevation in leads V1-V3.

Brugada Syndrome: ECG

Brugada Syndrome: ECG

Spontaneous polymorphic ventricular tachycardia recordedduring monitoring in a patient with Brugada syndrome.The arrhythmias are fast and need DC shock to terminate.

Brugada Syndrome: Clinical Features

• unexpectad sudden death

• syncope, seizures

• agonal nocturnal respirations

• affects male patients predominantly (8:1)

• cases reported worldwide

Brugada Syndrome: Incidence and Distribution

• responsible for up to 50% of sudden death victims with structurally normal hearts in Thailand

• recognized in Asia for decades:– Philippines: Bangungut = scream followed by

sudden death during sleep– Thailand: Lai tai = death during sleep– Japan: Pokuri = unexpected death during

sleep

Brugada Syndrome: ECG

Brugada Syndrome: ECG

12-lead ECG during administration of ajmaline (50 mg in 5 min). Note the progressive appearance of the ST elevation in V1-V3.

Brugada Syndrome: Factors / Drugs that Enhance ECG Pattern

• Na+ channel blockers

• alpha agonists, vagotonic agents, beta blockers

• fever

• alcohol, cocaine

• severe ischemia

• tricyclic antidepressants, antihistaminics

Brugada Syndrome: Genetics

• autosomal dominant• 60 different mutations in the SCN5A

(chromosome 3) gene have been linked to the syndrome

• failure of alpha subunit of sodium channel to express

• shift in voltage and time dependence on I(Na+) activation, inactivation or reactivation

Brugada Syndrome: Diagnosis

• symptoms: syncope, SCD (usually during sleep)• physical exam: normal• family history: strong history of SCD• ECG: best test to identify Brugada patients

– may require Flecainide or Procainamide to bring out typical findings

– ST elevation, RBBB

• imaging tests: usually no underlying structural disease

• stress tests: symptoms and ECG findings not usually reproducible with exercise

Brugada Syndrome: Diagnostic Criteria

• major criteria:– 1. presence of ECG marker in structurally normal

hearts– 2. appearance of ECG marker after administration of

Na+ channel blockers

• minor criteria:– 1. family history of sudden cardiac death– 2. syncope of unknown origin– 3. documented ventricular tachycardia/fibrillation– 4. genetic mutation of ion channels

Brugada Syndrome: Treatment

• IMPLANTABLE CARDIOVERTER-DEFIBRILLATOR (ICD)

• symptomatic with the disease: ICD• asymptomatic with family history of SCD: with normal

ECG – OBSERVE• asymptomatic with prolonged H-V interval and inducible

VT/VF: controversial ICD

Potential Antiarrhythmic Drugs in Brugada Syndrome

• Quinidine (non specific I blocker)

• Isoproterenol (open L type calcium channel)

• Cilostazol (augment I Ca)

Conclusion

• sudden cardiac death in Southeast Asia

• characteristic ECG pattern – ST elevation in V1 – V3

• ICD implantation in symptomatic patients

Thank you!