Long-term prognosis of probands with Brugada-pattern ST-elevation in leads V1-V3

Brugada syndrome in Iran: Insights from a 12-year longitudinal study

BACKGROUND

Brugada syndrome (BrS) is characterized by ST-segment elevation in the right precordial leads, which is not explained by ischemia, electrolyte disturbances, or obvious structural heart disease.

AIM

In present study, we aim to evaluate presentation, long-term outcome, genetic findings, and therapeutic interventions in patients with BrS.

METHODS

Between September 2001 and June 2022, all consecutive patients with diagnosis of BrS were enrolled in the present study. All patients gave written informed consent for the procedure, and the local ethical committee approved the study.

RESULTS

Of the 76 cases, 79% were proband and 21% were detected during screening after diagnosis of BrS in a family member. Thirty-three (43%) patients had a typical spontaneous electrocardiogram (ECG) pattern. Thirty percent of the patients were symptomatic; symptomatic patients were more likely to have spontaneous type 1 Brugada ECG pattern in their ECGs (p = .01), longer PR interval (p = .03), and SCN5A mutation (p = .01) than asymptomatic patients. The mean PR interval was considerably longer in men than women (p = .034). SCN5A mutation was found in 9 out of 50 (18%) studied patients. Fifteen percent received appropriate implantable cardioverter-defibrillator (ICD) therapy and inappropriate ICD interventions were observed in 17%. Presentation with aborted SCD or arrhythmic syncope was the only predictor of adverse outcome in follow-up (odds ratio: 3.1, 95% confidence interval: 0.7-19.6, p = .001).

CONCLUSIONS

Symptomatic patients with BrS are more likely to present with spontaneous type 1 Brugada ECG pattern, longer PR interval, and pathogenic mutation in SCN5A gene. Appropriate ICD interventions are more likely in symptomatic patients and those with SCN5A mutation.

Predicting Risk of Cardiac Arrest in Young Asian Americans: Insights from an Artificial Neural Network Analysis of the Nationwide Cohort

We used the Artificial Neural Network (ANN) model to identify predictors of Sudden Cardiac Arrest (SCA) in a national cohort of young Asian patients in the United States. The National Inpatient Sample (2019) was used to identify young Asians (18-44-year-old) who were hospitalized with SCA. The neural network's predicted criteria for SCA were selected. After eliminating missing data, young Asians (n = 65,413) were randomly divided into training (n = 45,094) and testing (n = 19347) groups. Training data (70%) was used to calibrate ANN while testing data (30%) was utilized to assess the algorithm's accuracy. To determine ANN's performance in predicting SCA, we compared the frequency of incorrect prediction between training and testing data and measured the area under the Receiver Operating Curve (AUC). The 2019 young Asian cohort had 327,065 admissions (median age 32 years; 84.2% female), with SCA accounting for 0.21%. The exact rate of error in predictions vs. tests was shown by training data (0.2% vs 0.2%). In descending order, the normalized importance of predictors to accurately predict SCA in young adults included prior history of cardiac arrest, sex, age, diabetes, anxiety disorders, prior coronary artery bypass grafting, hypertension, congenital heart disease, income, peripheral vascular disease, and cancer. The AUC was 0.821, indicating an excellent ANN model for SCA prediction. Our ANN models performed excellently in revealing the order of important predictors of SCA in young Asian American patients. These findings could have a considerable impact on clinical practice to develop risk prediction models to improve the survival outcome in high-risk patients.

Brugada Syndrome: A Comprehensive Review of Fundamental and Electrophysiological New Findings

Brugada syndrome is characterized by pronounced J-ST segment elevation in the right precordial leads on surface electrocardiograms. The etiological underpinnings of these distinctive features have been the subject of extensive debate, encompassing various theories related to repolarization anomalies and conduction irregularities. Genetic investigations have unveiled SCN5A, the gene encoding NaV1.5, a critical sodium channel, as the most frequently implicated causative gene, with mutations typically manifesting as loss of function. Nonetheless, the detection rate of SCN5A mutations remains below 20%, underscoring the intricate genetic landscape of the syndrome. Histological analyses have divulged localized structural irregularities, primarily marked by fibrotic alterations, within the right ventricular outflow tract. Electrophysiological inquiries employing direct epicardial mapping techniques have uncovered localized conduction impediments concomitant with modifications in unipolar morphologies within the J-ST segment. Thus, the theory positing conduction abnormalities emerges as a compelling mechanism accounting for J-ST segment elevation. However, the precise mechanisms governing the onset of life-threatening tachyarrhythmias remain shrouded in uncertainty. Recent clinical case reports have proffered evidence supporting the notion that phase 2 reentry, arising from the marked heterogeneity in action potentials within the epicardial domain, may serve as the instigator of premature ventricular contractions, ultimately culminating in ventricular fibrillation. In light of these developments, it becomes increasingly evident that comprehending the mechanisms underlying the electrocardiographic manifestations and lethal arrhythmias in Brugada syndrome necessitates the consideration of a multifaceted perspective, transcending the binary discourse of repolarization versus depolarization anomalies.

Prediction of the Presence of Ventricular Fibrillation From a Brugada Electrocardiogram Using Artificial Intelligence

BACKGROUND

Brugada syndrome is a potential cause of sudden cardiac death (SCD) and is characterized by a distinct ECG, but not all patients with A Brugada ECG develop SCD. In this study we sought to examine if an artificial intelligence (AI) model can predict a previous or future ventricular fibrillation (VF) episode from a Brugada ECG.Methods and Results: We developed an AI-enabled algorithm using a convolutional neural network. From 157 patients with suspected Brugada syndrome, 2,053 ECGs were obtained, and the dataset was divided into 5 datasets for cross-validation. In the ECG-based evaluation, the precision, recall, and F1score were 0.79±0.09, 0.73±0.09, and 0.75±0.09, respectively. The average area under the receiver-operating characteristic curve (AUROC) was 0.81±0.09. On per-patient evaluation, the AUROC was 0.80±0.07. This model predicted the presence of VF with a precision of 0.93±0.02, recall of 0.77±0.14, and F1score of 0.81±0.11. The negative predictive value was 0.94±0.11 while its positive predictive value was 0.44±0.29.

CONCLUSIONS

This proof-of-concept study showed that an AI-enabled algorithm can predict the presence of VF with a substantial performance. It implies that the AI model may detect a subtle ECG change that is undetectable by humans.

Investigation of High-Risk Electrocardiographic Markers as Predictors of Major Arrhythmic Events in Brugada Syndrome: A Systematic Review and Meta-analysis

INTRODUCTION

Numerous studies have demonstrated that a type I Brugada electrocardiographic (ECG) pattern, history of syncope, prior sudden cardiac arrest, and previously documented ventricular tachyarrhythmias are still insufficient to stratify the risk of sudden cardiac death in Brugada syndrome (BrS). Several auxiliary risk stratification parameters are pursued to yield a better prognostic model. Our aim was to assess the association between several ECG markers (wide QRS, fragmented QRS, S-wave in lead I, aVR sign, early repolarization pattern in inferolateral leads, and repolarization dispersion pattern) with the risk of developing poor outcomes in BrS.

METHODS

A systematic literature search from several databases was conducted from database inception until August 17^th, 2022. Studies were eligible if it investigated the relationship between the ECG markers with the likelihood of acquiring major arrhythmic events (MAE).

RESULTS

This meta-analysis comprised 27 studies with a total of 6552 participants. Our study revealed that wide QRS, fragmented QRS, S-wave in lead I, aVR sign, early repolarization pattern in inferolateral leads, and repolarization dispersion ECG pattern were associated with the incremental risk of syncope, ventricular tachyarrhythmias, implantable cardioverter-defibrillator shock, and sudden cardiac death in the future, with the risk ratios ranging from 1.41 to 2.00. Moreover, diagnostic test accuracy meta-analysis indicated that the repolarization dispersion ECG pattern had the highest overall area under curve (AUC) value amid other ECG markers regarding our outcomes of interest.

CONCLUSION

A multivariable risk assessment approach based on the prior mentioned ECG markers potentially improves the current risk stratification models in BrS patients.

Sudden Cardiac Death Risk Stratification of the Early Repolarization Syndrome: An Updated Review of the Literature

PURPOSE OF REVIEW

Early repolarization syndrome (ERS), once thought to be innocuous, has now been shown to be responsible for ventricular arrythmias and sudden cardiac death occurrence. This review will help the clinician to identify the patients who are most at risk for arrhythmias, so that they can adopt a preventive or secondary treatment approach, either of which is still poorly defined.

RECENT FINDINGS

Patients at high risk are found to be particularly young men, with a personal or family history of syncope or sudden death, who have an inferolateral ER on the electrocardiogram, more elevated J-point, longer J-wave duration and wider J angle, a horizontal or descending ST segment, lower T/R ratio, and small and/or inverted waves. The association with a structural heart disease or another channelopathy potentiates this arrhythmic risk. Taken together, these parameters allow prediction of the malignancy of ER pattern with a certain reliability. Further research is however needed to develop concrete risk stratification algorithms and the therapeutic strategies taken in function of it.

Brugada Syndrome: From Molecular Mechanisms and Genetics to Risk Stratification

Brugada syndrome (BrS) is a rare hereditary arrhythmia disorder, with a distinctive ECG pattern, correlated with an increased risk of ventricular arrhythmias and sudden cardiac death (SCD) in young adults. BrS is a complex entity in terms of mechanisms, genetics, diagnosis, arrhythmia risk stratification, and management. The main electrophysiological mechanism of BrS requires further research, with prevailing theories centered on aberrant repolarization, depolarization, and current-load match. Computational modelling, pre-clinical, and clinical research show that BrS molecular anomalies result in excitation wavelength (k) modifications, which eventually increase the risk of arrhythmia. Although a mutation in the SCN5A (Sodium Voltage-Gated Channel Alpha Subunit 5) gene was first reported almost two decades ago, BrS is still currently regarded as a Mendelian condition inherited in an autosomal dominant manner with incomplete penetrance, despite the recent developments in the field of genetics and the latest hypothesis of additional inheritance pathways proposing a more complex mode of inheritance. In spite of the extensive use of the next-generation sequencing (NGS) technique with high coverage, genetics remains unexplained in a number of clinically confirmed cases. Except for the SCN5A which encodes the cardiac sodium channel NaV1.5, susceptibility genes remain mostly unidentified. The predominance of cardiac transcription factor loci suggests that transcriptional regulation is essential to the Brugada syndrome's pathogenesis. It appears that BrS is a multifactorial disease, which is influenced by several loci, each of which is affected by the environment. The primary challenge in individuals with a BrS type 1 ECG is to identify those who are at risk for sudden death, researchers propose the use of a multiparametric clinical and instrumental strategy for risk stratification. The aim of this review is to summarize the latest findings addressing the genetic architecture of BrS and to provide novel perspectives into its molecular underpinnings and novel models of risk stratification.

Risk stratification of ventricular fibrillation in patients with symptomatic Brugada syndrome using pharmacological tests

BACKGROUND

Brugada syndrome (BrS), which is characterized by J-point elevation in right precordial leads of a 12-lead electrocardiogram, is associated with the occurrence of ventricular fibrillation (VF). However, risk stratification of VF in patients with BrS remains challenging.

OBJECTIVE

The aim of this study was to identify a risk predictor of VF in patients with BrS using pharmacological tests.

METHODS

Twenty-one consecutive patients with BrS and a history of documented spontaneous VF (n = 16) or syncope presumed to be caused by lethal ventricular arrhythmia (n = 5) were enrolled. J-wave changes in response to intravenous verapamil, propranolol, and pilsicainide were separately assessed.

RESULTS

During the median follow-up period of 86.0 months, 8 patients had VF recurrence (recurrence group) and 13 patients did not have VF recurrence (non-recurrence group). Intravenous propranolol injection induced significant J-wave augmentation (i.e., increase in amplitude >0.1 mV) in the inferior and/or lateral leads in the recurrence group compared to the non-recurrence group (p = .048 and p = .015, respectively). Kaplan-Meier analysis revealed that VF recurrence is significantly higher in patients with BrS and J-wave augmentation due to intravenous propranolol than in patients without J-wave augmentation (p = .014).

CONCLUSION

The study results show that propranolol-induced J-wave augmentation is involved in the risk of VF in patients with BrS. The results suggest that early repolarization patterns in response to pharmacological tests may be useful for risk stratification of VF in patients with symptomatic BrS.

Brugada Syndrome as a Major Cause of Sudden Cardiac Death in Asians

Brugada syndrome (BrS) is one of the main inherited arrhythmia syndromes causing ventricular fibrillation (VF) and sudden cardiac death in young to middle-aged men, especially in Asians. The diagnosis of BrS is based on spontaneous or drug-provoked type 1 Brugada electrocardiogram. The current reliable therapy for BrS patients with VF history is the implantation of an implantable cardioverter-defibrillator. As for BrS patients without VF history, how asymptomatic BrS patients should effectively be treated is still uncertain because risk stratification of the BrS is still inadequate. Various parameters and combinations of several parameters have been reported for risk stratification of BrS. The SCN5A gene is believed to be the only gene that is responsible for BrS, and it has been reported to be useful for risk stratification. This review focuses on risk stratification of BrS patients, and focuses specifically on BrS patients of Asian descent.

Association of atrial septal defect and Brugada syndrome in a young woman

We report a 25-year-old woman who was diagnosed with atrial septal defect (ASD). An ECG showed only first-degree atrioventricular block and incomplete right bundle branch block. One day after the percutaneous ASD closure, she had a slight fever and an ECG showed a type 1 Brugada pattern. ECG characteristics of ASD are similar to those of a Brugada ECG. This case is rare combination of Brugada syndrome with ASD.

Exercise in the Genetic Arrhythmia Syndromes - A Review

Provide a brief summary of your article (100-150 words; no references or figures/tables). The synopsis appears only in the table of contents and is often used by indexing services such as PubMed. Genetic arrhythmia syndromes are rare, yet harbor the potential for highly consequential, often unpredictable arrhythmias or sudden death events. There has been historical uncertainty regarding the correct advice to offer to affected patients who are reasonably wanting to participate in sporting and athletic endeavors. In some cases, this had led to abundantly cautious disqualifications, depriving individuals from participation unnecessarily. Societal guidance and expert opinion has evolved significantly over the last decade or 2, along with our understanding of the genetics and natural history of these conditions, and the emphasis has switched toward shared decision making with respect to the decision to participate or not, with patients and families becoming better informed, and willing participants in the decision making process. This review aims to give a brief update of the salient issues for the busy physician concerning these syndromes and to provide a framework for approaching their management in the otherwise aspirational or keen sports participant.

Risk stratification of sudden cardiac death in Brugada syndrome: an updated review of literature

Brugada syndrome is a rare but serious inherited heart disease that causes sudden cardiac death by polymorphic ventricular tachycardia or ventricular fibrillation. It is an autosomal dominant genetic disease that usually occurs in patients in their forties with a structurally normal heart. Electrically, it manifests by ST elevation segment ≥ 2 mm of at least one right precordial lead (V1 and/or V2). Stratification of sudden cardiac death in Brugada syndrome is not always easy and constitutes a real challenge for the practitioner. In this review, we will present the current state of knowledge for arrhythmic risk stratification and the prevention of sudden cardiac death that can result from this syndrome.

Brugada Syndrome

Brugada syndrome (BrS) is an "inherited" condition characterized by predisposition to syncope and cardiac arrest, predominantly during sleep. The prevalence is ∼1:2,000, and is more commonly diagnosed in young to middle-aged males, although patient sex does not appear to impact prognosis. Despite the perception of BrS being an inherited arrhythmia syndrome, most cases are not associated with a single causative gene variant. Electrocardiogram (ECG) findings support variable extent of depolarization and repolarization changes, with coved ST-segment elevation ≥2 mm and a negative T-wave in the right precordial leads. These ECG changes are often intermittent, and may be provoked by fever or sodium channel blocker challenge. Growing evidence from cardiac imaging, epicardial ablation, and pathology studies suggests the presence of an epicardial arrhythmic substrate within the right ventricular outflow tract. Risk stratification aims to identify those who are at increased risk of sudden cardiac death, with well-established factors being the presence of spontaneous ECG changes and a history of cardiac arrest or cardiogenic syncope. Current management involves conservative measures in asymptomatic patients, including fever management and drug avoidance. Symptomatic patients typically undergo implantable cardioverter defibrillator insertion, with quinidine and epicardial ablation used for patients with recurrent arrhythmia. This review summarizes our current understanding of BrS and provides clinicians with a practical approach to diagnosis and management.

dST-Tiso Interval, a Novel Electrocardiographic Marker of Ventricular Arrhythmia Inducibility in Individuals With Ajmaline-Induced Brugada Type I Pattern

The aim of this study was to investigate the reliability of a novel electrocardiographic (ECG) marker in predicting ventricular arrhythmia (VA) inducibility in individuals with drug-induced Brugada syndrome (BrS) type I pattern. Consecutive patients with drug-induced type I BrS pattern underwent programmed ventricular stimulation (PVS) and, according to their response, were divided into 2 groups. Clinical characteristics and 12-lead ECG intervals before and after ajmaline infusion were compared between the 2 groups. A novel ECG marker named dST-Tiso interval consisting in the interval between the onset of the coved ST-segment elevation and its termination at the isoelectric line was also evaluated. Our cohort included 76 individuals (median age 44 years, 75% male). Twenty-five (32.9%) had VA inducibility requiring defibrillation. As compared with not inducible subjects, those with VA inducibility were more frequently male (92% vs 65%, p = 0.013), had longer PQ interval (basal: 172 vs 152 ms, p = 0.033; after ajmaline: 216 vs 200 ms, p = 0.040), higher J peak (0.6 vs 0.5 mV, p = 0.006) and longer dST-Tiso (360 vs 240 ms, p < 0.001). The dST-Tiso showed a C-statistics of 0.90 (95% confidence interval: 0.82 to 0.99) and an adjusted odds ratio for VA of 1.03 (1.01 to 1.04, p < 0.001). A dST-Tiso interval >300 ms yielded a sensitivity of 92.0%, a specificity of 90.2%, positive and negative predictive values of 82.1% and 95.8%. In conclusion, the dST-Tiso interval is a powerful predictor of VA inducibility in drug-induced BrS type I pattern. External validation is needed, but this marker might be useful in the clinical counseling process of these individuals before invasive PVS.

Prevalence and Related Characteristics of Patients with Brugada Pattern Electrocardiogram in Santa Catarina, Brazil

Fundamento:

A síndrome de Brugada é um distúrbio arritmogênico hereditário caracterizado pela presença de características eletrocardiográficas específicas com ou sem sintomas. Os pacientes apresentam risco aumentado de morte súbita por fibrilação ventricular. A prevalência desse padrão eletrocardiográfico difere de acordo com a região estudada. Porém, informações epidemiológicas, incluindo a população brasileira, são escassas.

Objetivo:

Avaliar a prevalência do padrão eletrocardiográfico da síndrome de Brugada e o perfil epidemiológico associado a ela.

Métodos:

Estudo transversal que incluiu 846.533 registros ECG de 716.973 pacientes do banco de dados de eletrocardiograma (ECG) da Rede de Telemedicina de Santa Catarina por um período de quatro anos. Todos os exames foram ECG de 12 derivações convencionais (sem V1 e V2 em posições altas). Os exames identificados com o diagnóstico de “Síndrome de Brugada” (tipos 1 e 2) foram revisados por um eletrofisiologista. Foram considerados significativos valores de p<0,05.

Resultados:

Apresentavam padrão potencialmente consistente com ECG do tipo Brugada 83 pacientes. Destes, 33 foram confirmados com padrão de Brugada tipo 1, e 22 com tipo 2, após reavaliação. A prevalência de ECG do tipo 1 de Brugada foi de 4,6 por 100.000 pacientes. O ECG do tipo Brugada 1 foi associado ao sexo masculino (81,8% vs. 41,5%, p<0,001) e menor prevalência de obesidade (9,1% vs. 26,4%, p=0,028).

Conclusões:

Este estudo mostrou baixa prevalência de ECG do tipo Brugada no sul do Brasil. A presença de ECG com padrão Brugada tipo 1 esteve associada ao sexo masculino e menor prevalência de obesidade que a população geral.

Validation of multiparametric approaches for the prediction of sudden cardiac death in patients with Brugada syndrome and electrophysiological study

INTRODUCTION AND OBJECTIVES

Multiparametric scores have been designed for better risk stratification in Brugada syndrome (BrS). We aimed to validate 3 multiparametric approaches (the Delise score, Sieira score and the Shanghai BrS Score) in a cohort with Brugada syndrome and electrophysiological study (EPS).

METHODS

We included patients diagnosed with BrS and previous EPS between 1998 and 2019 in 23 hospitals. C-statistic analysis and Cox proportional hazard regression models were used.

RESULTS

A total of 831 patients were included (mean age, 42.8±13.1; 623 [75%] men; 386 [46.5%] had a type 1 electrocardiogram (ECG) pattern, 677 [81.5%] were asymptomatic, and 319 [38.4%] had an implantable cardioverter-defibrillator). During a follow-up of 10.2±4.7 years, 47 (5.7%) experienced a cardiovascular event. In the global cohort, a type 1 ECG and syncope were predictive of arrhythmic events. All risk scores were significantly associated with events. The discriminatory abilities of the 3 scores were modest (particularly when these scores were evaluated in asymptomatic patients). Evaluation of the Delise and Sieira scores with different numbers of extra stimuli (1 or 2 vs 3) did not substantially improve the event prediction c-index.

CONCLUSIONS

In BrS, classic risk factors such as ECG pattern and previous syncope predict arrhythmic events. The predictive capabilities of the EPS are affected by the number of extra stimuli required to induce ventricular arrhythmias. Scores combining clinical risk factors with EPS help to identify the populations at highest risk, although their predictive abilities remain modest in the general BrS population and in asymptomatic patients.

Brugada syndrome and syncope: a practical approach for diagnosis and treatment

Syncope in patients with Brugada electrocardiogram pattern may represent a conundrum in the decision algorithm because incidental benign forms, especially neurally mediated syncope, are very frequent in this syndrome similarly to the general population. Arrhythmic syncope in Brugada syndrome typically results from a self-terminating sustained ventricular tachycardia or paroxysmal ventricular fibrillation, potentially leading to sudden cardiac death. Distinguishing syncope due to malignant arrhythmias from a benign form is often difficult unless an electrocardiogram is recorded during the episode. We performed a review of the existing literature and propose a practical approach for diagnosis and treatment of the patients with Brugada syndrome and syncope.

Risk stratification of patients with Brugada syndrome: the impact of myocardial strain analysis using cardiac magnetic resonance feature tracking

OBJECTIVE

This study evaluated the prognostic significance of cardiac magnetic resonance myocardial feature tracking (CMR-FT) in patients with Brugada syndrome (BrS) to detect subclinical alterations and predict major adverse events (MAE).

METHODS

CMR was performed in 106 patients with BrS and 25 healthy controls. Biventricular global strain analysis was assessed using CMR-FT. Patients were followed over a median of 11.6 [8.8 ± 13.8] years.

RESULTS

The study cohort was subdivided according to the presence of a spontaneous type 1 ECG (sECG) into sBrS (BrS with sECG, n = 34 (32.1%)) and diBrS (BrS with drug-induced type 1 ECG, n = 72 (67.9%)). CMR-FT revealed morphological differences between sBrS and diBrS patients with regard to right ventricular (RV) strain (circumferential (%) (sBrS -7.9 ± 2.9 vs diBrS - 9.5 ± 3.1, p = 0.02) and radial (%) (sBrS 12.0 ± 4.3 vs diBrS 15.4 ± 5.4, p = 0.004)). During follow-up, MAE occurred in 11 patients (10.4%). Multivariable analysis was performed to identify independent predictors for the occurrence of events during follow-up. The strongest predictive value was found for RV circumferential strain (OR 3.2 (95% CI 1.4 - 6.9), p = 0.02) and RVOT/BSA (OR 3.1 (95% CI 1.0 - 7.0), p = 0.03).

CONCLUSIONS

Myocardial strain analysis detected early subclinical alterations, prior to apparent changes in myocardial function, in patients with BrS. While usual functional parameters were within the normal range, CMR-FT revealed pathological results in patients with an sECG. Moreover, RV circumferential strain and RVOT size provided additional prognostic information on the occurrence of MAE during follow-up, which reflects electrical vulnerability.

Does the Age of Sudden Cardiac Death in Family Members Matter in Brugada Syndrome?

Background Brugada syndrome is an inherited cardiac channelopathy associated with major arrhythmic events (MAEs). The presence of a positive family history of sudden cardiac death (SCD) as a risk predictor of MAE remains controversial. We aimed to examine the association between family history of SCD and MAEs stratified by age of SCD with a systematic review and meta-analysis. Methods and Results We searched the databases of MEDLINE and EMBASE from January 1992 to January 2020. Data from each study were combined using the random-effects model. Fitted metaregression was performed to evaluate the association between the age of SCD in families and the risk of MAE. Twenty-two studies from 2004 to 2019 were included in this meta-analysis involving 3386 patients with Brugada syndrome. The overall family history of SCD was not associated with increased risk of MAE in Brugada syndrome (pooled odds ratio [OR], 1.11; 95% CI, 0.82-1.51; P=0.489, I²=45.0%). However, a history of SCD in family members of age younger than 40 years of age did increase the risk of MAE by ≈2-fold (pooled OR, 2.03; 95% CI, 1.11-3.73; P=0.022, I²=0.0%). When stratified by the age of cut point at 50, 45, 40, and 35 years old, a history of SCD in younger family member was significantly associated with a higher risk of MAE (pooled OR, 0.49, 1.30, 1.51, and 2.97, respectively; P=0.046). Conclusions A history of SCD among family members of age younger than 40 years was associated with a higher risk of MAE.

Precision Medicine Approaches to Cardiac Arrhythmias: JACC Focus Seminar 4/5

In the initial 3 papers in this Focus Seminar series, the fundamentals and key concepts of precision medicine were reviewed, followed by a focus on precision medicine in the context of vascular disease and cardiomyopathy. For the remaining 2 papers, we focus on precision medicine in the context of arrhythmias. Specifically, in this fourth paper we focus on long QT syndrome, Brugada syndrome, and atrial fibrillation. The final (fifth) paper will deal with catecholaminergic polymorphic ventricular tachycardia. These arrhythmias represent a spectrum of disease ranging from common to relatively rare, with very different genetic and environmental causative factors, and with differing clinical manifestations that range from almost no consequences to lethality in childhood or adolescence if untreated. Accordingly, the emerging precision medicine approaches to these arrhythmias vary significantly, but several common themes include increased use of genetic testing, avoidance of triggers, and personalized risk stratification to guide the use of arrhythmia-specific therapies.

Role of Catheter Ablation for Ventricular Arrhythmias in Brugada Syndrome

PURPOSE OF REVIEW

To discuss the role of catheter ablation in treating life-threatening ventricular arrhythmias associated with Brugada syndrome (BrS), by presenting recent findings of BrS arrhythmogenic substrate, mechanisms underlying ventricular arrhythmias, and how they can be treated with catheter ablation.

RECENT FINDINGS

Almost three decades ago when the clinical entity of Brugada syndrome (BrS) was described in patients who had abnormal coved-type ST elevation in the right precordial EKG leads in patients who had no apparent structural heart disease but died suddenly from ventricular fibrillation. Since its description, the syndrome has galvanized explosive research in this field over the past decades, driving major progress toward better understanding of BrS, gaining knowledge of the genetic pathophysiology and risk stratification of BrS, and creating significant advances in therapeutic modalities. One of such advances is the ability for electrophysiologists to map and identify the arrhythmogenic substrate sites of BrS, which serve as good target sites for catheter ablation. Subsequently, several studies have shown that catheter ablation of these substrates normalizes the Brugada ECG pattern and is very effective in eliminating these substrates and preventing recurrent VF episodes. Catheter ablation has become an important addition for treatment of symptomatic BrS patients with recurrent VT/VF episodes.

A 32-Year-Old Man Diagnosed with Type II Brugada Syndrome on Preoperative Electrocardiogram 1 Week Before Elective Tympanoplasty

Patient: Male, 32-year-old

Final Diagnosis: Brugada syndrome

Symptoms: No specific symptoms

Medication:—

Clinical Procedure: —

Specialty: Anesthesiology • Cardiology

Day-to-Day Variation of Early Repolarization Pattern Predicts Life-Threatening Arrhythmias in Patients With Brugada Syndrome

BACKGROUND

We assessed the relationship between day-to-day variation of the early repolarization (ER) pattern and ventricular tachyarrhythmia (VTA) events in Brugada syndrome (BrS) patients because the clinical implications are unclear.Methods and Results:This retrospective study consisted of 41 patients with BrS who underwent implantable cardioverter-defibrillator (ICD) implantation. BrS was diagnosed by a spontaneous or drug-induced type 1 ECG without structural heart disease. Day-to-day variation of the ER pattern was defined as temporal change in the J-point (≥0.1 mV) on ECG. VTA events were detected via ICD interrogation: 15 patients experienced VTA events during 124±62 months' observation. Day-to-day variation of the ER pattern was positive in 7 patients (17%). In the multivariate Cox proportional hazards model, day-to-day variation of a positive ER pattern (hazard ratio [HR]: 3.475, 95% confidence interval [CI]: 1.105-10.414, P=0.034) and documented history of VTA (HR: 4.802, 95% CI: 1.547-17.995, P=0.006) were independent predictors of VTA events. In patients with electrical storm (ES: n=9), day-to-day variation of the ER pattern was positive in 5 patients (56%). ES events were more frequently observed in patients with a positive day-to-day variation of ER pattern than in those without (P<0.05).

CONCLUSIONS

The incidence of day-to-day variation of the ER pattern was higher in patients with arrhythmic events of VTA and/or ES among BrS patients with ICD.

Long-term prognosis in patients with non-type 1 Brugada electrocardiogram: Results from a large Japanese cohort of idiopathic ventricular fibrillation

Background

Brugada syndrome (BrS) is diagnosed in patients with ST‐segment elevation with spontaneous, drug‐induced, or fever‐induced type 1 morphology. Prognosis in type 2 or 3 Brugada electrocardiogram (Br‐ECG) patients remains unknown. The purpose of this study is to evaluate long‐term prognosis in non‐type 1 Br‐ECG patients in a large Japanese cohort of idiopathic ventricular fibrillation (The Japan Idiopathic Ventricular Fibrillation Study [J‐IVFS]).

Methods

From 567 patients with Br‐ECG in J‐IVFS, a total of 28 consecutive non‐type 1 patients who underwent programmed electrical stimulation (PES) (median age: 58 years, all male, previous sustained ventricular tachyarrhythmias [VTs] 1, syncope 11, asymptomatic 16) were enrolled. Cardiac events (CEs: sudden cardiac death or sustained VT/ventricular fibrillation) during the follow‐up period were examined.

Results

During a median follow‐up of 136 months, four patients (14%) had CEs. None of patients with PES‐ have experienced CEs. There was no statistically significant clinical risk factor for the development of CEs. Using the Kaplan–Meier method, the event‐free rate significantly decreased in a group with all 3 risk factors (symptom, wide QRS complex in lead V₂, and positive PES) (p = .01).

Conclusions

Our study revealed long‐term prognosis in patients with non‐type 1 Br‐ECG. The combination analysis of these risk factors may be useful for the risk stratification of CEs in non‐type 1 Br‐ECG patients. The present study suggests that the patients with all these parameters showed high risk for CEs and need to be carefully followed.

Importance of thorough investigation in a patient presenting with recurrent collapse and ST elevation

There is increasing literature to suggest numerous subgroups of Brugada syndrome (BrS), including those with ST elevation in the lateral or inferior leads. We present a case of a patient presenting with recurrent collapse and inferior ST elevation degenerating to ventricular fibrillation and ultimately leading to a diagnosis of BrS.

Territory-wide cohort study of Brugada syndrome in Hong Kong: predictors of long-term outcomes using random survival forests and non-negative matrix factorisation

OBJECTIVES

Brugada syndrome (BrS) is an ion channelopathy that predisposes affected patients to spontaneous ventricular tachycardia/fibrillation (VT/VF) and sudden cardiac death. The aim of this study is to examine the predictive factors of spontaneous VT/VF.

METHODS

This was a territory-wide retrospective cohort study of patients diagnosed with BrS between 1997 and 2019. The primary outcome was spontaneous VT/VF. Cox regression was used to identify significant risk predictors. Non-linear interactions between variables (latent patterns) were extracted using non-negative matrix factorisation (NMF) and used as inputs into the random survival forest (RSF) model.

RESULTS

This study included 516 consecutive BrS patients (mean age of initial presentation=50±16 years, male=92%) with a median follow-up of 86 (IQR: 45-118) months. The cohort was divided into subgroups based on initial disease manifestation: asymptomatic (n=314), syncope (n=159) or VT/VF (n=41). Annualised event rates per person-year were 1.70%, 0.05% and 0.01% for the VT/VF, syncope and asymptomatic subgroups, respectively. Multivariate Cox regression analysis revealed initial presentation of VT/VF (HR=24.0, 95% CI=1.21 to 479, p=0.037) and SD of P-wave duration (HR=1.07, 95% CI=1.00 to 1.13, p=0.044) were significant predictors. The NMF-RSF showed the best predictive performance compared with RSF and Cox regression models (precision: 0.87 vs 0.83 vs. 0.76, recall: 0.89 vs. 0.85 vs 0.73, F1-score: 0.88 vs 0.84 vs 0.74).

CONCLUSIONS

Clinical history, electrocardiographic markers and investigation results provide important information for risk stratification. Machine learning techniques using NMF and RSF significantly improves overall risk stratification performance.

Clinical characteristics and long-term clinical course of patients with Brugada syndrome without previous cardiac arrest: a multiparametric risk stratification approach

AIMS

Risk stratification in Brugada syndrome (BrS) still represents an unsettled issue. In this multicentre study, we aimed to evaluate the clinical characteristics and the long-term clinical course of patients with BrS.

METHODS AND RESULTS

A total of 111 consecutive patients (86 males; aged 45.3 ± 13.3 years) diagnosed with BrS were included and followed-up in a prospective fashion. Thirty-seven patients (33.3%) were symptomatic at enrolment (arrhythmic syncope). An electrophysiological study (EPS) was performed in 59 patients (53.2%), and ventricular arrhythmias were induced in 32 (54.2%). A cardioverter defibrillator was implanted in 34 cases (30.6%). During a mean follow-up period of 4.6 ± 3.5 years, appropriate device therapies occurred in seven patients. Event-free survival analysis (log-rank test) showed that spontaneous type-1 electrocardiogram pattern (P = 0.008), symptoms at presentation (syncope) (P = 0.012), family history of sudden cardiac death (P < 0.001), positive EPS (P = 0.024), fragmented QRS (P = 0.004), and QRS duration in lead V2 > 113 ms (P < 0.001) are predictors of future arrhythmic events. Event rates were 0%, 4%, and 60% among patients with 0-1 risk factor, 2-3 risk factors, and 4-5 risk factors, respectively (P < 0.001). Current multiparametric score models exhibit an excellent negative predictive value and perform well in risk stratification of BrS patients.

CONCLUSIONS

Multiparametric models including common risk factors appear to provide better risk stratification of BrS patients than single factors alone.

Prevalence and Clinical Significance of Latent Brugada Syndrome in Atrial Fibrillation Patients Below 45 Years of Age

Aim: This study aims to describe prevalence and clinical significance of latent Brugada syndrome (BrS) in a young population with atrial fibrillation (AF).

Methods: Between September 2015 and November 2017, among 111 AF patients below 45 years of age, those without pre-existing pathologies and/or known risk factors were selected for the study. Based on baseline 12-lead−24-h Holter electrocardiogram (ECG), previous class 1C antiarrhythmic drug therapy, or ajmaline testing, patients were stratified as latent type 1 BrS or not.

Results: Within the 78 enrolled patients, 13 (16.7%; group 1) revealed a type 1 BrS ECG pattern, while 65 (83.3%; group 2) did not. Mean age was 37 ± 8 vs. 35 ± 7 (p = 0.42), and males were 7 (54%) vs. 54 (83%) (p = 0.02) in the two groups, respectively. Family history of BrS was significantly more common within group 1 patients (2, 15% vs. 0; p = 0.03), and 4 (31%) patients experienced syncope in group 1 vs. 5 (8%) in group 2 (p = 0.02). After a mean follow-up of 42 ± 18 months from the index AF event, more than 80% of the patients, in both study groups, were in sinus rhythm.

Conclusion: In young patients with AF without pre-existing pathologies and/or known risk factors, latent BrS should be suspected. Syncope and a family history of BrS emerge as easily identifiable factors related to BrS. Long-term sinus rhythm maintenance appears satisfactory, either in the presence or not of BrS.

A Primary Prevention Clinical Risk Score Model for Patients With Brugada Syndrome (BRUGADA-RISK)

OBJECTIVES

The goal of this study was to develop a risk score model for patients with Brugada syndrome (BrS).

BACKGROUND

Risk stratification in BrS is a significant challenge due to the low event rates and conflicting evidence.

METHODS

A multicenter international cohort of patients with BrS and no previous cardiac arrest was used to evaluate the role of 16 proposed clinical or electrocardiogram (ECG) markers in predicting ventricular arrhythmias (VAs)/sudden cardiac death (SCD) during follow-up. Predictive markers were incorporated into a risk score model, and this model was validated by using out-of-sample cross-validation.

RESULTS

A total of 1,110 patients with BrS from 16 centers in 8 countries were included (mean age 51.8 ± 13.6 years; 71.8% male). Median follow-up was 5.33 years; 114 patients had VA/SCD (10.3%) with an annual event rate of 1.5%. Of the 16 proposed risk factors, probable arrhythmia-related syncope (hazard ratio [HR]: 3.71; p < 0.001), spontaneous type 1 ECG (HR: 3.80; p < 0.001), early repolarization (HR: 3.42; p < 0.001), and a type 1 Brugada ECG pattern in peripheral leads (HR: 2.33; p < 0.001) were associated with a higher risk of VA/SCD. A risk score model incorporating these factors revealed a sensitivity of 71.2% (95% confidence interval: 61.5% to 84.6%) and a specificity of 80.2% (95% confidence interval: 75.7% to 82.3%) in predicting VA/SCD at 5 years. Calibration plots showed a mean prediction error of 1.2%. The model was effectively validated by using out-of-sample cross-validation according to country.

CONCLUSIONS

This multicenter study identified 4 risk factors for VA/SCD in a primary prevention BrS population. A risk score model was generated to quantify risk of VA/SCD in BrS and inform implantable cardioverter-defibrillator prescription.

Electrocardiographic interpretation in athletes

Participation in regular exercise of moderate intensity is associated with a plethora of systemic benefits, including a reduction in risk factors for coronary atherosclerosis; however, intensive exercise may paradoxically culminate in sudden cardiac arrest among individuals harboring arrhythmogenic substrates. The precise mechanism for arrhythmogenesis is likely multifactorial, however, surges in catecholamines, electrolyte shifts, acid-base disturbances, increased core temperature and demand myocardial ischemia are potential contributors. Although most deaths occur in middle aged and older males with atherosclerotic coronary artery disease, a significant proportion also affect young athletes with inherited or congenital cardiac abnormalities. The impact of such catastrophes on society, particularly when a young high-profile athlete is affected could be considered a justified reason for identifying individuals who may be at risk. Given the rarity of deaths in young athletes, only the simplest screening test, such as the 12-lead electrocardiography (ECG) may be considered to be cost effective. The ECG is effective for detecting serious electrical diseases in young athletes such as congenital electrical accessory pathways and ion channel diseases but can also identify athletes with potential life-threatening structural diseases such as hypertrophic and arrhythmogenic cardiomyopathy. One of the concerns about ECG screening is that regular intensive exercise results in several physiological alterations in cardiac structure and function that are reflected on the athlete's ECG. Sinus bradycardia, first-degree atrioventricular block, incomplete right bundle branch block, minor J-point elevation and large QRS voltages are common. Conversely, some repolarization anomalies affecting the ST segment, T waves and QT interval may overlap with patterns observed in patients with serious cardiac diseases. The situation is complicated further because age, sex and ethnicity of the athletes also influence the ECG and there is a risk that erroneous interpretation could have serious consequences. This review will describe the normal electrical patterns of the "athlete's heart" and provide insights into differentiation physiological electrical patterns from those observed in serious cardiac disease.

Improved Risk Stratification of Patients With Brugada Syndrome by the New Japanese Circulation Society Guideline - A Multicenter Validation Study

BACKGROUND

The new guideline (NG) published by the Japanese Circulation Society (JCS) places emphasis on previous arrhythmic syncope and inducibility of ventricular fibrillation (VF) by ≤2 extrastimuli during programmed electrical stimulation (PES) for deciding the indication of an implantable cardioverter-defibrillator in patients with Brugada syndrome (BrS). This study evaluated the usefulness of the NG and compared it with the former guideline (FG) for risk stratification of patients with BrS.Methods and Results:This was a multicenter (7 Japanese hospitals) retrospective study involving 234 patients with BrS who underwent PES at baseline (226 males; mean age at diagnosis: 44.9±13.4 years). At diagnosis, 46 patients (20%) had previous VF, 100 patients (43%) had previous syncope, and 88 patients (37%) were asymptomatic. We evaluated the difference in the incidence of VF in each indication according to the new and FGs. During the follow-up period (mean: 6.9±5.2 years), the incidence of VF was higher in patients with Class IIa indication according to the NG (NG: 16/45 patients [35.6%] vs. FG: 16/104 patients [15.4%]), while the incidence of VF in patients with other than class I or IIa indication was similarly low in both guidelines (NG: 2/143 patients [1.4%] vs. FG: 2/84 patients [2.4%]).

CONCLUSIONS

This study validated the usefulness of the NG for risk stratification of BrS patients.

Heart Disease and Stroke Statistics-2020 Update: A Report From the American Heart Association

BACKGROUND

The American Heart Association, in conjunction with the National Institutes of Health, annually reports on the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, diet, and weight) and health factors (cholesterol, blood pressure, and glucose control) that contribute to cardiovascular health. The Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, congenital heart disease, rhythm disorders, subclinical atherosclerosis, coronary heart disease, heart failure, valvular disease, venous disease, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The American Heart Association, through its Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States to provide the most current information available in the annual Statistical Update. The 2020 Statistical Update is the product of a full year's worth of effort by dedicated volunteer clinicians and scientists, committed government professionals, and American Heart Association staff members. This year's edition includes data on the monitoring and benefits of cardiovascular health in the population, metrics to assess and monitor healthy diets, an enhanced focus on social determinants of health, a focus on the global burden of cardiovascular disease, and further evidence-based approaches to changing behaviors, implementation strategies, and implications of the American Heart Association's 2020 Impact Goals.

RESULTS

Each of the 26 chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policy makers, media professionals, clinicians, healthcare administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

Brugada Syndrome: Clinical Care Amidst Pathophysiological Uncertainty

Brugada syndrome (BrS) is a complex clinical entity with ongoing conjecture regarding its genetic basis, underlying pathophysiology, and clinical management. Within this paradigm of uncertainty, clinicians are faced with the challenge of caring for patients with this uncommon but potentially fatal condition. This article reviews the current understanding of BrS and highlights the "known unknowns" to reinforce the need for flexible clinical practice in parallel with ongoing scientific discovery.

Identification of malignant early repolarization pattern by late QRS activity in high-resolution magnetocardiography

Background

The early repolarization pattern (ERP) in electrocardiography (ECG) has been considered as a risk for ventricular fibrillation (VF), but effective methods for identification of malignant ERP are still required. We investigated whether high spatiotemporal resolution 64‐channel magnetocardiography (MCG) would enable distinction between benign and malignant ERPs.

Methods

Among all 2,636 subjects who received MCG in our facility, we identified 116 subjects (43 ± 18 years old, 54% male) with inferior and/or lateral ERP in ECG and without structural heart disease, including 13 survivors of VF (ERP‐VF(+)) and 103 with no history of VF (ERP‐VF(−)). We measured the following MCG parameters in a time‐domain waveform of relative current magnitude: (a) QRS duration (MCG‐QRSD), (b) root‐mean‐square of the last 40 ms (MCG‐RMS40), and (c) low amplitude (<10% of maximal) signal duration (MCG‐LAS).

Results

Compared to ERP‐VF(−), ERP‐VF(+) subjects presented a significantly longer MCG‐QRS (108 ± 24 vs. 91 ± 23 ms, p = .02) and lower MCG‐RMS40 (0.10 ± 0.08 vs. 0.25 ± 0.20, p = .01) but no difference in MCG‐LAS (38 ± 22 vs. 29 ± 23 ms, p = .17). MCG‐QRSD and MCG‐RMS40 showed significantly larger area under the ROC curve compared to J‐peak amplitude in ECG (0.72 and 0.71 vs. 0.50; p = .04 and 0.03). The sensitivity, specificity, and odds ratio for identifying VF(+) based on MCG‐QRSD ≥ 100 ms and MCG‐RMS40 ≤ 0.24 were 69%, 74%, and 6.33 (95% CI, 1.80–22.3), and 92%, 48%, and 10.9 (95% CI, 1.37–86.8), respectively.

Conclusion

Magnetocardiography is an effective tool to distinguish malignant and benign ERPs.

Low-Voltage Type 1 ECG Is Associated With Fatal Ventricular Tachyarrhythmia in Brugada Syndrome

Background

Epicardial mapping can reveal low‐voltage areas on the right ventricular outflow tract in patients with Brugada syndrome with several ventricular fibrillation (VF) episodes. A type 1 ECG is associated with an abnormal electrogram on right ventricular outflow tract epicardium. This study investigated the clinical significance of the amplitude of type 1 ECGs in patients with Brugada syndrome.

Methods and Results

In 209 patients with Brugada syndrome with a spontaneous type 1 ECG (26 resuscitated from VF, 54 with syncope, and 129 asymptomatic), the amplitude of the ECG in leads exhibiting type 1 was measured among V1 to V3 leads positioned in the standard and upper 1 and 2 intercostal spaces. The number of ECG leads exhibiting type 1 did not differ among groups. The averaged amplitude of type 1 ECG was, however, significantly smaller in the group resuscitated from VF than in the asymptomatic group (P<0.05). Moreover, the minimum amplitude of type 1 ECG was significantly smaller in the group resuscitated from VF than in the group with syncope and the asymptomatic group (P<0.05 and P<0.01, respectively). During follow‐up (56±48 months), VF occurred in 29 patients. Kaplan‐Meier analysis revealed that patients with the minimum amplitude of type 1 ECG lower than or at the median value had a higher incidence of VF (log‐rank test, P<0.01). In multivariate analysis, syncope, past VF episode, and minimum amplitude of type 1 ECG ≤0.8 mV were independent predictors of VF events during follow‐up.

Conclusions

Low‐voltage type 1 ECG is highly and independently related to fatal ventricular tachyarrhythmia in patients with Brugada syndrome.

Prediction and Prevention of Sudden Death in the Brugada Syndrome

Sudden cardiac death (SCD) secondary to sudden cardiac arrest (SCA) is a leading cause of death in the United States, claiming over a quarter million lives annually, and is directly responsible for 50% of all cardiovascular mortality. Brugada Syndrome (BrS) is an arrhythmogenic cardiovascular channelopathy that predisposes asymptomatic patients who have no identified disease to a high-risk of SCD/SCA as their first cardiac event/disease manifestation. Limited progress has been made in risk prediction of SCA and SCD, with the greatest challenge being the ability to identify the small high-risk subgroups concealed within the larger general population. In conclusion, accurate identification of high-risk asymptomatic BrS patients (through multiparametric risk scores composed of reliable and validated unambiguous clinical variables and biomarkers) may hold utility in improving current SCD prediction algorithms, and the appropriate primary prevention therapy may prove valuable in reducing risk of sudden death for this patient population. This systematic review aims to comprehensively summarize qualitative evidence that explore proposed clinical, electrocardiographic, electrophysiological, and genetic markers for risk stratification of patients with BrS phenotype, and to discuss the best available contemporary evidence regarding therapeutic approach.

Update on Brugada Syndrome 2019

Brugada syndrome (BrS) was first described in 1992 as an aberrant pattern of ST segment elevation in right precordial leads with a high incidence of sudden cardiac death (SCD) in patients with structurally normal heart. It represents 4% ∼ 12% of all SCD and 20% of SCD in patients with structurally normal heart. The extremely wide genetic heterogeneity of BrS and other inherited cardiac disorders makes this new area of genetic arrhytmology a fascinating one. This review shows the state of art in diagnosis, management, and treatment of BrS focusing all the aspects regarding genetics and Preimplant Genetic Diagnosis (PGD) of embryos, overlapping syndromes, risk stratification, familial screening, and future perspectives. Moreover the review analyzes key points like electrocardiogram (ECG) criteria, the role of electrophysiological study (the role of ventricular programmed stimulation and the need of universal accepted protocol) and the importance of a correct risk stratification to clarify when implantable cardioverter defibrillator or a close follow-up is needed. In recent years, cardiovascular studies have been focused on personalized risk assessment and to determine the most optimal therapy for an individual. The BrS syndrome has also benefited of these advances although there remain several key points to be elucidated. We will review the present knowledge, progress made, and future research directions on BrS.

Long-term prognosis of patients withJ-wave syndrome

OBJECTIVE

Limited data are currently available regarding the long-term prognosis of patients with J-wave syndrome (JWS). The aim of this study was to investigate the long-term prognosis of patients with JWS and identify predictors of the recurrence of ventricular fibrillation (VF).

METHODS

This was a multicentre retrospective study (seven Japanese hospitals) involving 134 patients with JWS (Brugada syndrome (BrS): 85; early repolarisation syndrome (ERS): 49) treated with an implantable cardioverter defibrillator. All patients had a history of VF. All patients with ERS underwent drug provocation testing with standard and high intercostal ECG recordings to rule out BrS. The impact of global J waves (type 1 ECG or anterior J waves and inferolateral J waves in two or more leads) on the prognosis was evaluated.

RESULTS

During the 91±66 months of the follow-up period, 52 (39%) patients (BrS: 37; ERS: 15) experienced recurrence of VF. Patients with BrS and ERS with global J waves showed a significantly higher incidence of VF recurrence than those without (BrS: log-rank, p=0.014; ERS: log-rank, p=0.0009). The presence of global J waves was a predictor of VF recurrence in patients with JWS (HR: 2.16, 95% CI 1.21 to 3.91, p=0.0095), while previously reported high-risk electrocardiographic parameters (high-amplitude J waves ≥0.2 mV and J waves associated with a horizontal or descending ST segment) were not predictive of VF recurrence.

CONCLUSIONS

This multicentre long-term study showed that the presence of global J waves was associated with a higher incidence of VF recurrence in patients with JWS.

Ethnic differences in patients with Brugada syndrome and arrhythmic events: New insights from Survey on Arrhythmic Events in Brugada Syndrome

BACKGROUND

There is limited information on ethnic differences between patients with Brugada syndrome (BrS) and arrhythmic events (AEs).

OBJECTIVE

The purpose of this study was to compare clinical, electrocardiographic (ECG), electrophysiological, and genetic characteristics between white and Asian patients with BrS and AEs.

METHODS

The Survey on Arrhythmic Events in Brugada Syndrome is a multicenter survey from Western and Asian countries, gathering 678 patients with BrS and first documented AE. After excluding patients with other (n = 14 [2.1%]) or unknown (n = 30 [4.4%]) ethnicity, 364 (53.7%) whites and 270 (39.8%) Asians comprised the study group.

RESULTS

There was no difference in AE age onset (41.3 ± 16.1 years in whites vs 43.3 ± 12.3 years in Asians; P = .285). Higher proportions of whites were observed in pediatric and elderly populations. Asians were predominantly men (98.1% vs 85.7% in whites; P < .001) and frequently presented with aborted cardiac arrest (71.1% vs 56%; P < .001). Asians tended to display more spontaneous type 1 BrS-ECG pattern (71.5% vs 64.3%; P = .068). A family history of sudden cardiac death was noted more in whites (29.1% vs 11.5%; P < .001), with a higher rate of SCN5A mutation carriers (40.1% vs 13.2% in Asians; P < .001), as well as more fever-related AEs (8.5% vs 2.9%; P = .011). No difference was observed between the 2 groups regarding history of syncope and ventricular arrhythmia inducibility.

CONCLUSION

There are important differences between Asian and white patients with BrS. Asian patients present almost exclusively as male adults, more often with aborted cardiac arrest and spontaneous type 1 BrS-ECG. However, they have less family history of sudden cardiac death and markedly lower SCN5A mutation rates. The striking difference in SCN5A mutation rates should be tested in future studies.

Markers of ventricular repolarization as an additional non-invasive electrocardiography parameters for predicting ventricular tachycardia/fibrillation in patients with Brugada Syndrome - A systematic review and meta-analysis

BACKGROUND

Controversies surrounded the management of asymptomatic Brugada syndrome. Prognostication using electrophysiology study (EPS) is disputable. Non-invasive parameters may be a valuable additional tool for risk stratification. We aim to evaluate the use markers of ventricular repolarization including Tpeak-to-Tend (TpTe), Tpe Dispersion, TpTe/QT ratio, and QTc interval as additional non-invasive electrocardiography parameters for predicting ventricular tachycardia/fibrillation in patients with Brugada syndrome.

METHODS

We performed a comprehensive search on TpTe, Tpe Dispersion, TpTe/QT ratio, and QTc interval as a predictor for ventricular tachycardia(VT)/fibrillation(VF)/aborted sudden cardiac death/appropriate ICD shock in patients with Brugada syndromes up until October 2018.

RESULTS

We included ten studies in the qualitative synthesis and eight studies in meta-analysis. There were a total of 2126 subjects from ten studies. We found that TpTe interval (mean difference 11.97 m s [5.02-18.91]; p < 0.001; I² 80% possibly on ≥80-100 m s and maximum QTc interval (mean difference 11.42 m s [5.90-16.93], p < 0.001; I² 28%) were the most potential ECG parameters to predict VT/VF/AT/SCD. Tpe dispersion and TpTe/QT ratio have a high heterogeneity. Upon sensitivity analysis, there is no single study found to markedly affect heterogeneity of Tpe dispersion and TpTe/QT ratio. Removal of a study reduced maximum QTc interval heterogeneity to 0%.

CONCLUSIONS

Measurement of TpTe interval, Tp-e dispersion, TpTe/QT ratio, and QTc interval on ECG emerge as a promising prognostication tool which needs further investigations with a more standardized method, outcome, and cut-off points. As for now, only maximum QTc interval has a reliable result with low heterogeneity sufficiently reliable for prognostication.

Clinical outcome of patients with the Brugada type 1 electrocardiogram without prophylactic implantable cardioverter defibrillator in primary prevention: a cumulative analysis of seven large prospective studies

Aims

Patients with the Brugada type 1 ECG (Br type 1) without previous aborted sudden death (aSD) who do not have a prophylactic ICD constitute a very large population whose outcome is little known. The objective of this study was to evaluate the risk of SD or aborted SD (aSD) in these patients.

Methods and results

We conducted a meta-analysis and cumulative analysis of seven large prospective studies involving 1568 patients who had not received a prophylactic ICD in primary prevention. Patients proved to be heterogeneous. Many were theoretically at low risk, in that they had a drug-induced Br type 1 (48%) and/or were asymptomatic (87%), Others, in contrast, had one or more risk factors. During a mean/median follow-up ranging from 30 to 48 months, 23 patients suffered SD and 1 had aSD. The annual incidence of SD/aSD was 0.5% in the total population, 0.9% in patients with spontaneous Br type 1 and 0.08% in those with drug-induced Br type 1 (P = 0.0001). The paper by Brugada et al. reported an incidence of SD more than six times higher than the other studies, probably as a result of selection bias. On excluding this paper, the annual incidence of SD/aSD in the remaining 1198 patients fell to 0.22% in the total population and to 0.38 and 0.06% in spontaneous and drug-induced Br type 1, respectively. Of the 24 patients with SD/aSD, 96% were males, the mean age was 39 ± 15 years, 92% had spontaneous Br type 1, 61% had familial SD (f-SD), and only 18.2% had a previous syncope; 43% had a positive electrophysiological study. Multiple meta-analysis of individual trials showed that spontaneous Br type 1, f-SD, and previous syncope increased the risk of SD/aSD (RR 2.83, 2.49, and 3.03, respectively). However, each of these three risk factors had a very low positive predictive value (PPV) (1.9-3.3%), while negative predictive values (NPV) were high (98.5-99.7%). The incidence of SD/aSD was only slightly higher in patients with syncope than in asymptomatic patients (2% vs. 1.5%, P = 0.6124). Patients with SD/aSD when compared with the others had a mean of 1.74 vs. 0.95 risk factors (P = 0.026).

Conclusion

(i) In patients with Br type 1 ECG without an ICD in primary prevention, the risk of SD/aSD is low, particularly in those with drug-induced Br type 1; (ii) spontaneous Br type 1, f-SD, and syncope increase the risk. However, each of these risk factors individually has limited clinical usefulness, owing to their very low PPV; (iii) patients at highest risk are those with more than one risk factor.

Pooled Analysis of Risk Stratification of Spontaneous Type 1 Brugada ECG: Focus on the Influence of Gender and EPS

Aims: Risk stratification of patients with Brugada syndrome (BrS) is vital for accurate prognosis and therapeutic decisions. Spontaneous Type 1 ST segment elevation is generally considered to be an independent risk factor for arrhythmic events. Other risk factors include gender, syncope, sudden cardiac arrest (SCA), and positive electrophysiological study (EPS). However, the further risk stratification of spontaneous type 1 combined with the other risk factors remains unclear. The present study pooled data from 4 large trials aiming to systematically evaluate the risk of spontaneous Type-1 ECG when combined with one or more of these other recognized risk factors.

Methods: We searched for related studies published from November 2, 2002 to February 10, 2018 in PubMed, EMBASE, Cochrane Library, MEDLINE, Chinese National Knowledge Infrastructure (CNKI), and Wanfang Databases. The pooled data were evaluated combining each risk factor with the presence of a spontaneous Type-1 ECG. All analyses were performed using Review Manager, version 5.0.12.

Results: Four eligible studies involving 1,338 patients (85% males, mean age: 48.1 ± 18.1 years) were enrolled. Spontaneous Type-1 ECG was associated with higher risk for ventricular tachycardia/fibrillation (VT/VF) than cases with non-Type 1 ECG in males (odds ratio: 95% CI: 1.84–5.17; P < 0.0001), but not in females (P = 0.29). Among spontaneous Type-1 cases with syncope or with positive EPS, the difference was not statistically significant (P = 0.06 and 0.07, respectively). Patients with Type-1 ECGs and positive EPS were at higher risk than those with negative EPS (95% CI: 1.10–5.04; P = 0.03). Pooled analysis showed an association of Spontaneous Type-1 ECG, Type-1 ECGs combined with male, and Type-1 ECGs combined with positive EPS between increased risk of arrhythmic events.

Conclusion: Our results indicate that in BrS patients, a spontaneous Type-1 ECG is an independent risk factor for SCD in males, but not in females. A spontaneous Type-1 BrS is associated with a worse prognosis when combined with positive EPS