From the Guidelines
Brugada syndrome patients with a history of cardiac arrest or spontaneous sustained ventricular tachycardia should undergo implantable cardioverter-defibrillator (ICD) implantation as the primary treatment to prevent sudden cardiac death. This recommendation is based on the most recent guidelines from the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines and the Heart Rhythm Society 1. The diagnosis of Brugada syndrome is made through characteristic ECG patterns showing ST-segment elevation in the right precordial leads (V1-V3), often with a "coved" or "saddleback" appearance, and can be confirmed with a pharmacological challenge using a sodium channel blocker in patients without a spontaneous type 1 Brugada electrocardiographic pattern 1.
Some key points to consider in the management of Brugada syndrome include:
- Avoidance of drugs that may induce ST-segment elevation in right precordial leads, which can be found on the Brugada Drugs website, and avoidance of excessive alcohol intake and large meals 1
- Prompt treatment of any fever with antipyretic drugs, as elevated temperatures can unmask or worsen the ECG pattern 1
- Quinidine or isoproterenol may be considered in patients with Brugada syndrome to treat electrical storms, and quinidine may also be used in patients who qualify for an ICD but present a contraindication or refuse it 1
- Genetic testing and family screening are recommended since the condition follows an autosomal dominant inheritance pattern 1
The prevalence of Brugada syndrome is higher in Southeast Asia than in western countries, and it is inherited as a dominant trait with age- and sex-related penetrance, affecting men more frequently than women 1. The incidence of arrhythmic events in patients with Brugada syndrome is significant, with a rate of 13.5% per year in patients with a history of sudden cardiac arrest, 3.2% per year in patients with syncope, and 1% per year in asymptomatic patients 1.
ICD implantation should be considered in patients with a spontaneous diagnostic type I ECG pattern and history of syncope, and may be considered in patients with a diagnosis of Brugada syndrome who develop VF during PVS with two or three extrastimuli at two sites. Additionally, catheter ablation may be considered in patients with a history of electrical storms or repeated appropriate ICD shocks 1.
From the Research
Definition and Diagnosis of Brugada Syndrome
- Brugada syndrome is an inherited channelopathy with an increased risk of sudden cardiac death (SCD) due to ventricular arrhythmias (VA) and an increased incidence of supraventricular arrhythmias 2.
- The diagnosis of Brugada syndrome is mainly based on the presence of a spontaneous or Na+-channel blocker induced "type 1" Brugada electrocardiographic (ECG) pattern typically seen in leads V1 and V2 recorded from the 4th to 2nd intercostal spaces 3.
- A single oral dose of flecainide can be used to unmask type 1 Brugada syndrome electrocardiographic pattern in patients with a suggestive but not diagnostic Brugada ECG or family history of sudden death 4.
Risk Stratification and Treatment
- The main unresolved clinical problem in Brugada syndrome is the identification of patients at high risk of SCD who need implantable cardioverter-defibrillator (ICD) 3.
- Current guidelines recommend ICD implantation only in patients with spontaneous type 1 ECG pattern and either history of aborted cardiac arrest or documented sustained ventricular tachycardia (class I) or syncope of arrhythmic origin (class IIa) 3.
- Quinidine therapy has been demonstrated to be effective in preventing VA in Brugada syndrome, especially in patients with ICD and recurrent shocks or in asymptomatic patients with inducible ventricular fibrillation (VF) at electrophysiological study 2.
- Subcutaneous implantable cardioverter-defibrillator (S-ICD) therapy can be a useful alternative to transvenous ICD (TV-ICD) in patients with Brugada syndrome, with no significant difference in the incidence of inappropriate shocks between the two groups 5.
Diagnostic Tools and Techniques
- Implantable loop recorders (ILR) can be used to study patients with unexplained recurrent syncopal events, and can contribute to the exclusion of a ventricular arrhythmia as a mechanism of an atypical syncope in patients with electrocardiographic Brugada syndrome 6.
- ILR can also help identify episodes of transient symptomatic bradycardia, suggesting a vagal mechanism of symptoms 6.
- Computerised quantitative ECG analysis of large digital ECG databases in patients with Brugada syndrome and their relatives can be a useful tool for novel risk assessment strategies 3.