What is Brugada syndrome?

From the Guidelines

Brugada syndrome is a rare genetic heart disorder that requires immediate attention to prevent sudden cardiac death, and the primary treatment for high-risk patients is an implantable cardioverter-defibrillator (ICD) to prevent sudden cardiac death, as recommended by the 2017 AHA/ACC/HRS guideline 1.

Diagnosis and Treatment

The diagnosis of Brugada syndrome is made through specific ECG patterns showing ST-segment elevation in the right precordial leads (V1-V3), often with a characteristic "coved" or "saddleback" appearance, and can be confirmed with a pharmacological challenge using a sodium channel blocker, such as ajmaline or flecainide, as stated in the 2015 ESC guidelines 1. The treatment for Brugada syndrome includes:

• ICD implantation for high-risk patients, such as those with a history of cardiac arrest, spontaneous type 1 ECG pattern, or family history of sudden death, as recommended by the 2017 AHA/ACC/HRS guideline 1
• Quinidine (300-600 mg three times daily) as adjunctive therapy to suppress arrhythmias, particularly in patients with frequent ICD shocks or those who cannot receive an ICD, as suggested by the 2018 AHA/ACC/HRS guideline 1
• Avoidance of triggers like certain medications, excessive alcohol, and high fever, as recommended by the 2015 ESC guidelines 1

Risk Stratification

Risk stratification is crucial in managing Brugada syndrome, and the following factors are associated with an increased risk of sudden cardiac death:

• Previous cardiac arrest
• Spontaneous type 1 ECG pattern
• Family history of sudden death
• Syncope presumed due to ventricular arrhythmias As stated in the 2017 AHA/ACC/HRS guideline, an electrophysiological study with programmed ventricular stimulation using single and double extrastimuli may be considered for further risk stratification in asymptomatic patients with a spontaneous type 1 Brugada electrocardiographic pattern 1.

Genetic Testing

Genetic testing can identify mutations in the SCN5A gene (present in about 20-30% of cases) and help with family screening, as mentioned in the 2018 AHA/ACC/HRS guideline 1. First-degree relatives of affected individuals should undergo screening with ECG and possibly drug challenge tests using sodium channel blockers like flecainide or ajmaline under careful monitoring.

Lifestyle Changes

The following lifestyle changes are recommended for patients with Brugada syndrome:

• Avoidance of drugs that may induce ST-segment elevation in right precordial leads (http://www.brugadadrugs.org)
• Avoidance of excessive alcohol intake and large meals
• Prompt treatment of any fever with antipyretic drugs, as recommended by the 2015 ESC guidelines 1

From the Research

Definition and Treatment of Brugada Syndrome

• Brugada syndrome (BrS) is an inherited disease characterized by an increased risk of sudden cardiac death (SCD) 2.
• Therapeutic options in symptomatic patients are limited to implantable cardioverter defibrillator (ICD) and quinidine, but catheter ablation of the right ventricular outflow tract (RVOT) offers a potential cure 2.

Implantable Cardioverter-Defibrillator (ICD) Therapy

• ICD therapy is effective for primary and secondary prevention of SCD in BrS 3, 4.
• Appropriate shocks occur more frequently in BrS patients presenting with VT/VF, but also occur in asymptomatic patients 3.
• Type 1 Brugada pattern is an independent predictor of appropriate shock delivery 3.
• ICD therapy is associated with a significant risk of device-related complications 4.

Catheter Ablation Therapy

• Catheter ablation has emerged as a promising treatment to prevent ventricular fibrillation (VF) in BrS 2, 5.
• Epicardial substrate ablation significantly reduces VF recurrence in symptomatic BrS patients with ICDs and appears safe 5.
• Ablation targeted arrhythmogenic areas identified through electroanatomical mapping, predominantly at the right ventricular epicardium 5.

Subcutaneous Implantable Cardioverter-Defibrillators (S-ICDs)

• S-ICDs are an alternative to transvenous systems, with reduced risk of infection and complications associated with system extraction or explantation 6.
• Electrocardiographic eligibility for S-ICD placement can be assessed using automated screening tools, and exercise stress testing (EST) can influence eligibility 6.
• A significant proportion of patients with BrS may no longer be eligible for an S-ICD after EST 6.