Brugada syndrome

Abstract

Brugada syndrome (BrS) is an inherited cardiac arrhythmia syndrome that causes a heightened risk for ventricular tachyarrhythmias and sudden cardiac death. BrS is characterised by a coved ST-segment elevation in right precordial leads. The prevalence is estimated to range between 1 in 5,000 to 1 in 2,000 in different populations, with the highest being in Southeast Asia and in males. More than 18 genes associated with BrS have been discovered and recent evidence has suggested a complex polygenic mode of inheritance with multiple common and rare genetic variants acting in concert to produce the BrS phenotype. Diagnosis of BrS in patients currently relies on presentation with a type-1 Brugada pattern on ECG either spontaneously or following a drug provocation test using a sodium channel blocker. Risk assessment in patients diagnosed with BrS is controversial, especially with regard to the predictive value of programmed electrical stimulation and novel ECG parameters, such as QRS fragmentation. The first line of BrS therapy remains an implantable cardioverter defibrillator (ICD), although radiofrequency catheter ablation has been shown to be an effective option in patients with contraindications for an ICD. True BrS can be unmasked on ECG in susceptible individuals by monitoring factors such as fever, and this has been recently evident in several patients infected with the 2019 novel coronavirus (COVID-19). Aggressive antipyretic therapy and regular ECG monitoring until fever resolves are current recommendations to help reduce the arrhythmic risk in these COVID-19 patients. In this review, we summarise the current knowledge on the epidemiology, pathophysiology, genetics, clinical diagnosis, risk stratification and treatment of patients with BrS, with special emphasis on COVID-19 comorbidity.

Cascade screening can be life-saving: a family with multiple cases of brugada syndrome and sudden cardiac death

“…Furthermore, men experience arrhythmic events at earlier ages and have more severe phenotypes [9]. The effect of sex hormones and differences in the expression of cardiac transmembrane channels are supposed to be responsible for gender differences in BrS [1,10]. Similarly, in this family, more men were affected (7 men versus 3 women).…”

“…Brugada Syndrome (BrS) is an inheritable cardiac channelopathy, mainly characterized by a particular electrocardiogram (ECG) pattern consisting of coved-typed J point elevations > 0.2 mV in ≥ 1 right precordial leads with T wave inversions in the absence of cardiac structural abnormalities [1]. Patients with BrS are more amenable to ventricular arrhythmia/fibrillation (VA/VF) and sudden cardiac death (SCD).…”

“…As far as 20% of SCD cases with structurally normal hearts happen in BrS patients [2]. Family history of SCD in close relatives has been reported in about 26% of cases, and numerous genes are involved in the pathogenesis of BrS [1,3] Although an autosomal dominant mode of inheritance has been reported, incomplete penetrance and variable expressivity may be the results of a complex of multiple genetic and environmental factors that control the BrS pattern of inheritance [4]. Nevertheless, after the diagnosis of the disease in a patient, all first-degree relatives should undergo screening as 67% of cases may be asymptomatic [5].…”

The “Heart” of COVID-19

“…According to this theory, epicardial dispersion of repolarization results in certain epicardial sites undergoing all-or-nothing repolarization at the end of Phase 1 of the cardiac action potential (Sieira et al, 2016). Heterogeneous repolarization is known to lead to Phase II reentry, which involves the occurrence of premature extrasystolic beats that are capable of initiating VT or VF (Korlipara, Korlipara, & Pentyala, 2020; Tse, 2016).…”

Brugada Syndrome and Anesthesia: A Systematic Review

“…Even in people with a similar ECG pattern of brugada the symptoms can vary from dizziness, fainting, shortness of breath, palpitations, and seizures to even some people being completely asymptomatic with the diagnosis of brugada being only an incidental ECG finding (7). Furthermore, it has come to light recently that brugada pattern can sometimes be unmasked in individuals who have inherited the disorder because of other conditions such a fever, injuries, COVID and other viral illnesses, stress and even certain medications and anesthetic agents (8).…”