Brugada Syndrome within Asian Populations: State-of-the-Art Review

Abstract

Brugada syndrome (BrS) is an inherited cardiac channelopathy with variable expressivity that can lead to sudden cardiac arrest (SCA). Studies worldwide suggest that BrS and Brugada pattern (BrP) have low prevalences in general. However, studies also note that BrS is most prevalent among certain Asian populations. Among the different global regions, the highest prevalence is believed to be in Southeast Asia, followed by the Middle East, South Asia, East Asia, Europe, and North America. It is not only important to recognize such varying degrees of BrS prevalence within Asia but also to understand that there may be significant differences in terms of presenting symptoms, occult risk factors, and the impact on clinical outcomes. The importance of identifying such differences lies in the necessity to develop improved risk assessment strategies to guide secondary prevention and treatment for these patients. Specifically, the decision to pursue placement of an implantable cardiac defibrillator (ICD) can be lifesaving for high-risk BrS patients. However, there remains a significant lack of consensus on how to best risk stratify BrS patients. While the current guidelines recommend ICD implantation in patients with spontaneous Type 1 ECG pattern BrS who present with syncope, there may still exist additional clinical factors that may serve as better predictors or facilitate more refined risk stratification before malignant arrhythmias occur. This carries huge relevance given that BrS patients often do not have any preceding symptoms prior to SCA. This review seeks to delineate the differences in BrS presentation and prevalence within the Asian continent in the hope of identifying potential risk factors to guide better prognostication and management of BrS patients in the future.

Identifying genomic variant associated with long QT syndrome type 2 in an ecuadorian mestizo individual: a case report

“…Also, each ethnic group with LQTS is associated with a specific more prevalent genetic variant. For example, genetic variants in the SCN5A gene of individuals with LQTS are more prevalent in African American people, increasing the risk of sudden death ( Killen et al, 2010 ), while Brugada syndrome (BrS) associated with SCN5A variants have been reported more frequently in Caucasians and Asians individuals ( Milman et al, 2019 ; Chen et al, 2020 ; Nakano and Shimizu, 2022 ), although BrS phenotype is more prevalent in East and Southeast Asia ( Nakano and Shimizu, 2022 ; Khawaja et al, 2023 ). Instead, genetic variants in the KCNQ1 and KCNH2 genes have been described to be more prevalent in people with European and Japanese ancestry ( Lahrouchi et al, 2020 ; Winbo et al, 2020 ).…”

Brugada syndrome precipitated by an antimalarial agent: a case report

“…Arrhythmic manifestations and cardiac arrest in BrS tend to occur in men and populations in Southeast Asian countries. (1,2) Clinical manifestations of BrS can vary from mild discomfort in the form of syncope to sudden death, mostly caused by malignant arrhythmias. It is an autosomal dominant arrhythmia characterized by ST elevation and negative T waves in right heart electrocardiography (ECG) leads without structural cardiac abnormalities, which occur because of mutations in the cardiac sodium gene SCN5A resulting in loss of cardiac sodium channel function, decreased sodium in ux, and depolarization phase shortening of the action potential, which is also associated with sudden cardiac death (3).…”

“…It is an autosomal dominant arrhythmia characterized by ST elevation and negative T waves in right heart electrocardiography (ECG) leads without structural cardiac abnormalities, which occur because of mutations in the cardiac sodium gene SCN5A resulting in loss of cardiac sodium channel function, decreased sodium in ux, and depolarization phase shortening of the action potential, which is also associated with sudden cardiac death (3). BrS is endemic in Southeast Asian and East Asian countries (2). This may be due to poor reporting or diagnosis resulting from facility limitations.…”

Image1.JPEG

“…Also, each ethnic group with LQTS is associated with a specific more prevalent genetic variant. For example, genetic variants in the SCN5A gene of individuals with LQTS are more prevalent in African American people, increasing the risk of sudden death (Killen et al, 2010), while Brugada syndrome (BrS) associated with SCN5A variants have been reported more frequently in Caucasians and Asians individuals (Milman et al, 2019;Chen et al, 2020;Nakano and Shimizu, 2022), although BrS phenotype is more prevalent in East and Southeast Asia (Nakano and Shimizu, 2022;Khawaja et al, 2023). Instead, genetic variants in the KCNQ1 and KCNH2 genes have been described to be more prevalent in people with European and Japanese ancestry (Lahrouchi et al, 2020;Winbo et al, 2020).…”