Brugada’s Syndrome and Sudden Cardiac Death Brugada’s Syndrome and Sudden Cardiac Death Petra Lovrec Petra Lovrec Mentor: A. Žmegač Horvat
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 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 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 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