Clinical significance of inferolateral early repolarisation and late potentials in children with Brugada Syndrome

INTRODUCTION

The clinical utility of inferolateral early repolarisation (ER) and late potentials (LP) in children with Brugada Syndrome (BrS) has not been previously evaluated. The aim of this study was to determine the prevalence of electrocardiographic (ECG) abnormalities in children with BrS, and to investigate their relationship with clinical outcomes.

METHODS

43 patients with BrS and 47 controls aged ≤18 undergoing systematic clinical and ECG evaluation, including signal-averaged ECG (SAECG) and pharmacological provocation testing, between 2003 and 2019 were included.

RESULTS

Four patients with BrS (9%) presented with a spontaneous type 1 Brugada pattern; the remaining 39 (91%) were diagnosed following ajmaline provocation testing. Twelve BrS patients (28%) had late potentials (LP) on SAECG compared to 1 (2%) in controls (p = 0.001). LP were more common in 5 patients with a high-risk phenotype (60% vs 24%) but this was not statistically significant. Twelve patients with BrS (28%) had inferolateral early repolarisation (ER) and 2 (5%) had fractionated QRS (f-QRS), but there were no statistically-significant differences with controls in these parameters. A significant arrhythmia (non-sustained ventricular tachycardia or atrial fibrillation) was seen in 4 patients (9%).

CONCLUSIONS

This study shows a high prevalence of SAECG abnormalities in children with BrS compared with controls, but this was not significantly associated with a high-risk phenotype.

Pharmacological Therapy in Brugada Syndrome

Brugada syndrome (BrS) is a cardiac disease caused by an inherited ion channelopathy associated with a propensity to develop ventricular fibrillation. Implantable cardioverter defibrillator implantation is recommended in BrS, based on the clinical presentation in the presence of diagnostic ECG criteria. Implantable cardioverter defibrillator implantation is not always indicated or sufficient in BrS, and is associated with a high device complication rate. Pharmacological therapy aimed at rebalancing the membrane action potential can prevent arrhythmogenesis in BrS. Quinidine, a class 1A antiarrhythmic drug with significant Ito blocking properties, is the most extensively used drug for the prevention of arrhythmias in BrS. The present review provides contemporary data gathered on all drugs effective in the therapy of BrS, and on ineffective or contraindicated antiarrhythmic drugs.

Brugada syndrome in children - Stepping into unchartered territory

Brugada syndrome (BrS) is an autosomal dominant inherited channelopathy. It is associated with a typical pattern of ST-segment elevation in the precordial leads V1-V3 and potentially lethal ventricular arrhythmias in otherwise healthy patients. It is frequently seen in young Asian males, in whom it has previously been described as sudden unexplained nocturnal death syndrome. Although it typically presents in young adults, it is also known to present in children and infants, especially in the presence of fever. Our understanding of the genetic pathogenesis and management of BrS has grown substantially considering that it has only been 24 years since its first description as a unique clinical entity. However, there remains much to be learned, especially in the pediatric population. This review aims to discuss the epidemiology, genetics, and pathogenesis of BrS. We will also discuss established standards and new innovations in the diagnosis, prognostication, risk stratification, and management of BrS. Literature search was run on the National Center for Biotechnology Information's website, using the Medical Subject Headings (MeSH) database with the search term "Brugada Syndrome" (MeSH), and was run on the PubMed database using the age filter (birth-18 years), yielding 334 results. The abstracts of all these articles were studied, and the articles were categorized and organized. Articles of relevance were read in full. As and where applicable, relevant references and citations from the primary articles were further explored and read in full.