Current electrocardiographic criteria for diagnosis of Brugada pattern: a consensus report

Case Report: Comprehensive evaluation of ECG phenotypes and genotypes in a family with Brugada syndrome carrying SCN5A-R376H

Background

Brugada syndrome (BrS) is a channelopathy that can lead to sudden cardiac death in the absence of structural heart disease. Patients with BrS can be asymptomatic or present with symptoms secondary to polymorphic ventricular tachycardia or ventricular fibrillation. Even though BrS can exhibit autosomal dominant inheritance, it is not easy to identify the phenotype and genotype in a family thoroughly.

Case

We report the case of a 20-year-old man with variants in SCN5A and RyR2 genes who was resuscitated from sudden cardiac death during sleep due to a ventricular fibrillation. The patient did not have underlying diseases. The routine laboratory results, imaging study, coronary angiogram, and echocardiogram (ECG) were normal. A type 1 BrS pattern was identified in one resting ECG. Furthermore, prominent J wave accentuation with PR interval prolongation was identified during therapeutic hypothermia. Therefore, we were easily able to diagnose BrS. For secondary prevention, the patient underwent implantable cardioverter defibrillator implantation. Before discharge, a genetic study was performed using next-generation sequencing. Genotyping was performed in the first-degree relatives, and ECG evaluations of almost all maternal and paternal family members were conducted. The proband and his mother showed SCN5A-R376H and RyR2-D4038Y variants. However, his mother did not show the BrS phenotype on an ECG. One maternal aunt and uncle showed BrS phenotypes.

Conclusion

Genetics alone cannotdiagnose BrS. However, genetics could supply evidence or direction for evaluating ECG phenotypes in family groups. This case report shows how family evaluation using ECGs along with a genetic study can be used in BrS diagnosis.

More than 30 years of Brugada syndrome: a critical appraisal of achievements and open issues

Over the last three decades, what is referred to as Brugada syndrome (BrS) has developed from a clinical observation of initially a few cases of sudden cardiac death (SCD) in the absence of structural heart disease with ECG signs of "atypical right bundle brunch block" to a predominantly electrocardiographic, and to a lesser extent genetic, diagnosis. Today, BrS is diagnosed in patients without overt structural heart disease and a spontaneous Brugada type 1 ECG pattern regardless of symptoms. The diagnosis of BrS is less clear in those with an only transient or drug-induced type 1 Brugada pattern, but should be considered in the presence of an arrhythmic syncope, family history of BrS, or family history of sudden death. In addition to survived cardiac arrest, syncope is probably the single most decisive risk marker for future arrhythmias. For asymptomatic BrS, risk stratification remains challenging. General recommendations to lower the risk in BrS include avoidance of drugs/agents known to induce and/or increase right precordial ST-segment elevation, including treatment of fever with antipyretic drugs. Several ECG markers that have been associated with an increased risk of SCD have been incorporated into a recently published risk score for BrS. The aim of this article is to provide an overview of the status of risk stratification and to illustrate open issues und gaps in evidence in BrS.

Mannitol and hyponatremia regulate cardiac ventricular conduction in the context of sodium channel loss of function

Scn5a heterozygous null (Scn5a+/-) mice have historically been used to investigate arrhythmogenic mechanisms of diseases such as Brugada syndrome (BrS) and Lev's disease. Previously, we demonstrated that reducing ephaptic coupling (EpC) in ex vivo hearts exacerbates pharmacological voltage-gated sodium channel (Nav)1.5 loss of function (LOF). Whether this effect is consistent in a genetic Nav1.5 LOF model is yet to be determined. We hypothesized that loss of EpC would result in greater reduction in conduction velocity (CV) for the Scn5a+/- mouse relative to wild type (WT). In vivo ECGs and ex vivo optical maps were recorded from Langendorff-perfused Scn5a+/- and WT mouse hearts. EpC was reduced with perfusion of a hyponatremic solution, the clinically relevant osmotic agent mannitol, or a combination of the two. Neither in vivo QRS duration nor ex vivo CV during normonatremia was significantly different between the two genotypes. In agreement with our hypothesis, we found that hyponatremia severely slowed CV and disrupted conduction for 4/5 Scn5a+/- mice, but 0/6 WT mice. In addition, treatment with mannitol slowed CV to a greater extent in Scn5a+/- relative to WT hearts. Unexpectedly, treatment with mannitol during hyponatremia did not further slow CV in either genotype, but resolved the disrupted conduction observed in Scn5a+/- hearts. Similar results in guinea pig hearts suggest the effects of mannitol and hyponatremia are not species specific. In conclusion, loss of EpC through either hyponatremia or mannitol alone results in slowed or disrupted conduction in a genetic model of Nav1.5 LOF. However, the combination of these interventions attenuates conduction slowing.NEW & NOTEWORTHY Cardiac sodium channel loss of function (LOF) diseases such as Brugada syndrome (BrS) are often concealed. We optically mapped mouse hearts with reduced sodium channel expression (Scn5a+/-) to evaluate whether reduced ephaptic coupling (EpC) can unmask conduction deficits. Data suggest that conduction deficits in the Scn5a+/- mouse may be unmasked by treatment with hyponatremia and perinexal widening via mannitol. These data support further investigation of hyponatremia and mannitol as novel diagnostics for sodium channel loss of function diseases.

Severe hypothyroidism as a trigger for Brugada-type ECG abnormalities: a case report and literature review

Brugada syndrome (BrS) is an inherited disorder that can cause ventricular fibrillation and sudden cardiac death in individuals with otherwise structurally normal hearts. Several provoking factors are known to potentially unmask or exacerbate a typical Brugada ECG pattern in predisposed subjects. Hypothyroidism has been suggested as one of these triggers, but the exact mechanisms underlying this relationship remain poorly understood. Moreover, the severity of thyroid dysfunction beyond which a Brugada-type ECG alteration might be triggered is still unclear. We report the case of a 33-year-old male who displayed a Brugada type 1 ECG pattern and was diagnosed with severe hypothyroidism (TSH > 100 mU/L with undetectable levels of fT4 and fT3). Hormonal replacement therapy with levothyroxine was initiated at increasing doses; serial biochemical and ECG controls were performed, initially every 3 weeks up to 15 weeks and afterward every 3 months. The regression of typical Brugada ECG waveforms could be seen at an early stage, when the patient was still taking a low dose of levothyroxine (37.5 µg/day, i.e., one-fourth of his final requirements of 150 µg/day), and laboratory tests still showed a marked alteration of thyroid hormonal parameters. Hypothyroidism may act as a trigger for Brugada-type ECG abnormalities, but a very severe alteration of the hormonal parameters is necessary to prompt these alterations. In our case, the initiation of replacement therapy with levothyroxine rapidly reversed the ECG modifications, even at a low subtherapeutic dose.

Prevalence of Brugada electrocardiographic pattern in adult population - A community-based study from Kerala, South India

There is no data for Brugada electrocardiographic pattern (BrEP) from India. In a cross-sectional study of men and women between the ages 20-79 years, electrocardiograms were analyzed following the 2002 consensus. The overall prevalence of BrEP was 1.06 % (95 % CI 0.76, 1.35). There were two cases type I (0.04 %; 95 % CI 0.01, 0.06) and forty-seven type II/III (1.01 %; 95 % CI 1.02, 1.35); the pattern was markedly higher in men. In this study, BrEP was slightly less prevalent compared to South Asia but more than in the west.

Clinical Management of Brugada Syndrome: Commentary From the Experts

Although there is consensus on the management of patients with Brugada Syndrome with high risk for sudden cardiac arrest, asymptomatic or intermediate-risk patients present clinical management challenges. This document explores the management opinions of experts throughout the world for patients with Brugada Syndrome who do not fit guideline recommendations. Four real-world clinical scenarios were presented with commentary from small expert groups for each case. All authors voted on case-specific questions to evaluate the level of consensus among the entire group in nuanced diagnostic and management decisions relevant to each case. Points of agreement, points of controversy, and gaps in knowledge are highlighted.

The electrocardiographic manifestations of pectus excavatum before and after surgical correction

BACKGROUND

Pectus excavatum (PEx) can cause cardiopulmonary limitations due to cardiac compression and displacement. There is limited data on electrocardiogram (ECG) alterations before and after PEx surgical repair, and ECG findings suggesting cardiopulmonary limitations have not been reported. The aim of this study is to explore ECG manifestations of PEx before and after surgery including associations with exercise capacity.

METHODS

A retrospective review of PEx patients who underwent primary repair was performed. ECGs before and after surgical correction were evaluated and the associations between preoperative ECG abnormalities and cardiopulmonary function were investigated.

RESULTS

In total, 310 patients were included (mean age 35.1 ± 11.6 years). Preoperative ECG findings included a predominant negative P wave morphology in V1, and this abnormal pattern significantly decreased from 86.9% to 57.4% (p < 0.001) postoperatively. The presence of abnormal P wave amplitude in lead II (>2.5 mm) significantly decreased from 7.1% to 1.6% postoperatively (p < 0.001). Right bundle branch block (RBBB) (9.4% versus 3.9%, p < 0.001), rsr' patterns (40.6% versus 12.9%, p < 0.001), and T wave inversion in leads V1-V3 (62.3% vs 37.7%, p < 0.001) were observed less frequently after surgery. Preoperative presence of RBBB (OR = 4.8; 95%CI 1.1-21.6) and T wave inversion in leads V1-3 (OR = 2.3; 95%CI 1.3-4.2) were associated with abnormal results in cardiopulmonary exercise testings.

CONCLUSION

Electrocardiographic abnormalities in PEx are frequent and can revert to normal following surgery. Preoperative RBBB and T wave inversion in leads V1-3 suggested a reduction in exercise capacity, serving as a marker for the need for further cardiovascular evaluation of these patients.

The relevance of electrocardiogram filtering in the differential diagnosis of Brugada syndrome: An illustrative case report

We present a clinical case of a teenager in whom a Brugada syndrome electrical pattern was found which was finally diagnosed as a Brugada phenocopy due to a wrong setup of the high-pass filter on the electrocardiogram.

Explaining the Unexplained: A Practical Approach to Investigating the Cardiac Arrest Survivor

Sudden cardiac arrest (SCA) is a common cause of death. The majority of SCA is caused by ventricular arrhythmia due to underlying CHD. Aborted SCA with no apparent diagnosis after initial assessment with ECG, echocardiography and coronary assessment is referred to as unexplained cardiac arrest (UCA). Systematic evaluation of such patients may reveal a specific diagnosis in up to half of patients before a diagnosis of idiopathic VF is assigned. Specific diagnoses include inherited cardiac conditions, such as latent cardiomyopathies or inherited primary electrical disease. Identifying the cause of UCA is therefore not only critical for appropriate management of the SCA survivors to prevent recurrence, but also for their family members who may be at risk of the same condition. This review provides a tiered, systematic approach for the investigation of UCA.

Twelve-Lead ECG, Holter Monitoring Parameters, and Genetic Testing in Brugada Syndrome: Insights from Analysis of Multigenerational Family with a History of Sudden Cardiac Arrest during Physical Activity

Brugada syndrome (BrS) is an arrhythmogenic disorder increasing the risk of syncopal episodes and sudden cardiac death. BrS usually runs through families with reduced penetrance and variable expression. We analyzed the multigenerational family of a patient who died after sudden cardiac arrest with post-mortem diagnosis of BrS. We analyzed clinical history, comprehensive arrhythmic risk, genetic findings, and additional tests, including electrocardiogram (ECG), detailed 24-hour Holter ECG results, and standard echocardiography findings, and followed up the patients in the ambulatory clinic. We analyzed a pedigree of 33 members of four generations of the family (19 male and 14 female patients). In this family, we identified 7 patients with BrS (median Modified Shanghai Score and Sieira model: 4.5 (4-6) and 1 (0-4) points, respectively), including both parents of the deceased patient, and 8 relatives with negative sodium channel blocker drug challenge test. Genetic testing revealed a novel mutation in sodium voltage-gated channel alpha subunit 5 (SCN5A) c.941A>G, (p.Tyr314Cys) inherited from the father of the proband. Patients with BrS were characterized by longer P-wave duration (120 (102-155) vs. 92.5 (88-110) ms, p = 0.013) and longer PR intervals (211.3 ±26.3 vs. 161.6 ± 18.9 ms, p = 0.001), along with more frequent positive aVR sign, but did not differ in terms of QRS duration or T-wave characteristics in resting ECGs. BrS patients were characterized by lower mean, minimal, and maximal (for all p ≤ 0.01) heart rates obtained from Holter ECG monitoring, while there was no difference in arrhythmias among investigated patients. Moreover, visual diurnal variability of ST segment changes and fragmented QRS complexes were observed in patients with BrS in Holter ECG monitoring. There were no major arrhythmic events during median follow-up of 68.7 months of alive BrS patients. These results suggest ECG features which may be associated with a diagnosis of BrS and indicate a novel SCN5A variant in BrS patients. Twelve-lead Holter ECG monitoring, with modified precordial leads placement, may be useful in BrS diagnostics and risk stratification in personalized medicine.

An Unusual First Presentation of Stroke and Seizure in a 32-Year-Old Patient With Brugada Syndrome Type 2 Electrocardiogram Pattern

We report a case of a 32-year-old lady who was admitted to the hospital with right-sided weakness that preceded an episode of seizure. On the day of admission, she woke up early in the morning with mild right-sided weakness and numbness. She had difficulty walking and later had a seizure, which was witnessed by her son. She had no signs of infection prior to this. She had no fever, chest or abdominal pain, or urinary symptoms. In the emergency department, she complained of left-sided chest tightness and heaviness, which lasted for a few minutes with associated tachycardia, electrocardiogram (ECG) was consistent with Brugada syndrome type 2. A magnetic resonant imaging (MRI) scan of her head shows a left hemispheric infarct involving the frontoparietal cortex. She was treated for an ischaemic stroke and seizure. She made a good recovery and was discharged home on secondary stroke prevention medication with community physiotherapy. She was followed up in the cardiology, genetics, and stroke outpatient clinics. The occurrence of ECG changes consistent with Brugada syndrome, stroke, and seizure in a young patient with no other risk factors for stroke is rare.

Brugada Phenocopy Induced by Hypovolemic Hyponatremia

Brugada syndrome (BrS) is a hereditary channelopathy caused by an autosomal dominant mutation in the cardiac sodium channel gene SCN5A alpha subunit. In individuals without structural heart disease, the risk of sudden cardiac death (SCD) increases in this channelopathy with ST-segment elevation in V1-3 precordials. Brugada phenocopy (BrP) is a condition in which transient ST-segment elevations are observed, mimicking BrS electrocardiographic changes, which can occur with electrolyte and metabolic disorder scenarios. In this study, we share a case of BrP that occurred due to hypovolemic hyponatremia and recovered spontaneously with the correction of electrolyte disturbance.

Propofol in ICU Settings: Understanding and Managing Anti-Arrhythmic, Pro-Arrhythmic Effects, and Propofol Infusion Syndrome

Propofol has revolutionized anesthesia and intensive care medicine owing to its favorable pharmacokinetic characteristics, fast onset, and short duration of action. This drug has been shown to be remarkably effective in numerous clinical scenarios. In addition, propofol has maintained an overwhelmingly favorable safety profile; however, it has been associated with both antiarrhythmic and proarrhythmic effects. This review concisely summarizes the dual arrhythmic cardiovascular effects of propofol and a rare but serious complication, propofol infusion syndrome (PRIS). We also discuss the need for careful patient evaluation, compliance with recommended infusion rates, and vigilant monitoring.

Association Between Postresuscitation 12-Lead ECG Features and Early Mortality After Out-of-Hospital Cardiac Arrest: A Post Hoc Subanalysis of the PEACE Study

Background Once the return of spontaneous circulation after out-of-hospital cardiac arrest is achieved, a 12-lead ECG is strongly recommended to identify candidates for urgent coronary angiography. ECG has no apparent role in mortality risk stratification. We aimed to assess whether ECG features could be associated with 30-day survival in patients with out-of-hospital cardiac arrest. Methods and Results All the post-return of spontaneous circulation ECGs from January 2015 to December 2018 in 3 European centers (Pavia, Lugano, and Vienna) were collected. Prehospital data were collected according to the Utstein style. A total of 370 ECGs were collected: 287 men (77.6%) with a median age of 62 years (interquartile range, 53-70 years). After correction for the return of spontaneous circulation-to-ECG time, age >62 years (hazard ratio [HR], 1.78 [95% CI, 1.21-2.61]; P=0.003), female sex (HR, 1.5 [95% CI, 1.05-2.13]; P=0.025), QRS wider than 120 ms (HR, 1.64 [95% CI, 1.43-1.87]; P<0.001), the presence of a Brugada pattern (HR, 1.49 [95% CI, 1.39-1.59]; P<0.001), and the presence of ST-segment elevation in >1 segment (HR, 1.75 [95% CI, 1.59-1.93]; P<0.001) were independently associated with 30-day mortality. A score ranging from 0 to 26 was created, and by dividing the population into 3 tertiles, 3 classes of risk were found with significantly different survival rate at 30 days (score 0-4, 73%; score 5-7, 66%; score 8-26, 45%). Conclusions The post-return of spontaneous circulation ECG can identify patients who are at high risk of mortality after out-of-hospital cardiac arrest earlier than other forms of prognostication. This provides important risk stratification possibilities in postcardiac arrest care that could help to direct treatments and improve outcomes in patients with out-of-hospital cardiac arrest.

Ventricular Fibrillation in an Afebrile COVID-19 Patient Presenting With Transient Type-I Brugada Pattern

COVID-19 has been associated with an increased risk of both atrial and ventricular arrhythmias. Brugada syndrome (BrS), an inherited sodium channelopathy presenting with a characteristic ECG morphology, confers a baseline risk of ventricular arrhythmias such as ventricular fibrillation (VF), especially during febrile illnesses. However, mimics of BrS, termed Brugada phenocopies (BrP), have been noted in association with fever, electrolyte abnormalities, and toxidromes outside of viral illness. Such presentations manifest the same ECG pattern, the type-I Brugada pattern (type-I BP). Thus, the acute stage of an illness such as COVID-19, when accompanied by a first-time presentation of type-I BP, may not result in a certain diagnosis of BrS versus BrP. Thus, expert recommendations are to anticipate arrhythmia regardless of the presumed diagnosis. Here we demonstrate the importance of these guidelines and a novel report of VF in the setting of a transient type-I BP in afebrile COVID-19. We discuss the potential factors which may have triggered VF, the presentation of isolated "coved" ST elevation in V1, and the difficulty of BrS versus BrP diagnosis in acute illness. In summary, a SARS-CoV-2 positive 65-year-old male without significant cardiac history for BrS presented with type-I BP after two days of shortness of breath. Hypoxemia, hyperkalemia, hyperglycemia, elevated inflammatory markers, and acute kidney injury were present. After treatment, his ECG normalized; however, aborted VF occurred days later while afebrile and normokalemic. Follow-up ECG again revealed a type-I BP, which also became more apparent during an episode of bradycardia, a classic finding in BrS. This case suggests that there is room for larger studies to determine the prevalence and outcomes when type-I BP presents in acute COVID-19. When possible, genetic data should be obtained to confirm BrS, a notable limitation in our case. Regardless, it corroborates guideline-directed clinical management, with heightened vigilance for arrhythmia in such patients until full recovery.

Frontier and hotspot evolution in Brugada syndrome: A bibliometric analysis from 2002 to 2022

BACKGROUND

Brugada syndrome (BrS) is a genetic disorder characterized by a typical electrocardiogram pattern and predisposition to arrhythmias and sudden cardiac death. Despite our considerably evolved understanding of BrS, no bibliometrics have been performed in this research field. We aimed to analyze and visualize the characteristics of the scientific outputs, topical evolutions, and research trends of BrS over the past 2 decades using bibliometric analysis.

METHODS

The literature associated with BrS was retrieved from the Science Citation Index Expanded of the Web of Science Core Collection database. Acquired data were then visually analyzed using CiteSpace and VOSviewer.

RESULTS

3042 qualifying records were included in the final analysis. The publication outputs increased over time. The United States was the leading country in the BrS research. The University of Amsterdam (Netherlands) was the most prolific and influential institution. Pedro Brugada, Arthur Wilde, and Charles Antzelevitch exerted notable publication impact and made the most significant contributions in the field of BrS. Heart Rhythm had the highest outputs and Circulation was the most influential journal. Bundle branch block, ST-segment elevation, mechanism, management, right precordial lead, and guideline were the keywords with the strongest citation burst.

CONCLUSION

Research on BrS is prosperous. Keywords and co-citation analysis revealed that the mechanism, diagnosis, risk stratification, and management of BrS were the research hotspots. Besides, the underlying pathophysiology, novel therapies, and personalized risk assessment might be the emerging trends of future research.

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.

Delayed depolarization and histologic abnormalities underlie the Brugada syndrome

Brugada syndrome (BrS) is a controversial disease whose pathophysiology is still far from being fully understood. Unlike other cardiological disorders, a definite etiology has not yet been established so that it could be summarized under two main chapters: "functional" or "organic", "repolarization" or "depolarization" disorder. Despite initial descriptions leaned towards the organic substrate and delayed depolarization features, functional and repolarization theories have attracted most of the Cardiological attention for many years. Data from electrocardiography, endocavitary tracings, electroanatomic mapping and histopathology, however, demonstrated that BrS is mainly characterized by structural myocardial changes mostly at the right ventricular outflow tract (RVOT), but also at the right ventricle (RV) and by delayed conduction at the same sites. Conduction disorders at different levels may also be present and identify patients at high risk for major arrhythmic events. The aim of the present review is to provide the current state of art of the pathophysiology of BrS, focusing on electro-vectorcardiography and electrophysiological features, histopathology, echocardiography, and cardiac magnetic resonance imaging (CMRI).

Validation of an electrocardiographic marker of low voltage areas in the right ventricular outflow tract in patients with idiopathic ventricular arrhythmias

BACKGROUND

Previous studies have reported the presence of subtle abnormalities in the right ventricular outflow tract (RVOT) in patients with apparently normal hearts and ventricular arrhythmias (VAs) from the RVOT, including the presence of low voltage areas (LVAs). This LVAs seem to be associated with the presence of ST-segment elevation in V1 or V2 leads at the level of the 2nd intercostal space (ICS).

OBJECTIVE

Our aim was to validate an electrocardiographic marker of LVAs in the RVOT in patients with idiopathic outflow tract VAs.

METHODS

A total of 120 patients were studied, 84 patients referred for ablation of idiopathic VAs with an inferior axis by the same operator, and a control group of 36 patients without VAs. Structural heart disease including arrhythmogenic right ventricular cardiomyopathy was ruled out in all patients. An electrocardiogram was performed with V1-V2 at the 2nd ICS, and ST-segment elevation ≥1 mm and T-wave inversion beyond V1 were assessed. Bipolar voltage map of the RVOT was performed in sinus rhythm (0.5-1.5 mV color display). Areas with electrograms <1.5 mV were considered LVAs, and their presence was assessed. We compared three groups, VAs from the RVOT (n = 66), VAs from the LVOT (n = 18) and Control group (n = 36). ST-elevation, T-wave inversion and left versus right side of the VAs were tested as predictors of LVAs, respective odds ratio (ORs) (95% confidence interval [CI]) and p values, were calculated with univariate logist regression. Variables with a p < .005 were included in the multivariate analysis.

RESULTS

ST-segment elevation, T-wave inversion and LVAs were present in the RVOT group, LVOT group and Control group as follows: (62%, 17%, and 6%, p < .0001), (33%, 29%, and 0%, p = .001) and (62%, 25%, and 14%, p < .0001). The ST-segment elevation, T-wave inversion and right-sided VAs were all predictors of LVAs, respective unadjusted ORs (95% CI), p values were, 32.31 (11.33-92.13), p < .0001, 4.137 (1.615-10.60), p = .003 and 8.200 (3.309-20.32), p < .0001. After adjustment, the only independent predictor of LVAs was the ST-segment elevation, with an adjusted OR (95% CI) of 20.94 (6.787-64.61), p < .0001.

CONCLUSION

LVAs were frequently present in patients with idiopathic VAs. ST-segment elevation was the only independent predictor of their presence.

Defining electrocardiographic criteria to differentiate non-type 1 Brugada ECG variants from normal incomplete RBBB patterns in the young SCD-SOS cohort

INTRODUCTION

We assessed the prevalence of non-type 1 Brugada pattern (T1BrP) in children and young adults from the Sudden Cardiac Death-Screening Of risk factorS cohort and the diagnostic yield of nonexpert manual and automatic algorithm electrocardiogram (ECG) measurements.

METHODS

Cross-sectional study. We reviewed 14 662 ECGs and identified 2226 with a rSr'-pattern in V1-V2. Among these, 115 were classified by experts in hereditary arrhythmic-syndromes as having or not non-T1BrP, and were compared with measurements of 5 ECG-derived parameters based on a triangle formed by r' -wave (d(A), d(B), d(B)/h, β-angle) and ST-ascent, assessed both automatically and manually by nonexperts. We estimated intra- and interobserver concordance for each criterion, calculated diagnostic accuracy and defined the most appropriate cut-off values.

RESULTS

A rSr'-pattern in V1-V2 was associated with higher PQ interval and QRS duration, male gender, and lower body mass index (BMI). The manual measurements of non-T1BrP criteria were moderately reproducible with high intraobserver and moderate interobserver concordance coefficients (ICC: 0.72-0.98, and 0.63-0.76). Criteria with higher discriminatory capacity were: distance d(B) (0.72; 95% confidence interval [CI]: 0.65-0.80) and ST-ascent (0.87; 95% CI: 0.82-0.92), which was superior to the 4 r'-wave criteria together (area under curve [AUC: 0.74]). We suggest new cut-offs with improved combination of sensitivity and specificity: d(B) ≥ 1.4 mm and ST-ascent ≥ 0.7 mm (sensitivity: 1%-82%; specificity: 71%-84%), that can be automatically measured to allow classification in four morphologies with increasing non-T1BrP probability.

CONCLUSION

rSr'-pattern in precordial leads V1-V2 is a frequent finding and the detection of non-T1BrP by using the aforementioned five measurements is reproducible and accurate. In this study, we describe new cut-off values that may help untrained clinicians to identify young individuals who may require further work-up for a potential Brugada Syndrome diagnosis.

Diagnostic yield and variant reassessment in the genes encoding Nav1.5 channel in Russian patients with Brugada syndrome

Brugada syndrome (BrS) is an inherited cardiac arrhythmia characterized by ST-elevation, negative T-wave, and a high risk of sudden cardiac death (SCD) due to ventricular tachycardia. It is associated with mutations in over 20 genes but only SCN5A is recommended for routine genetic screening. This study was performed to estimate diagnostic yield and pathogenicity assessment of rare genetic variants in the genes encoding Nav1.5 channel in Russian patients with Brugada syndrome (BrS). Targeted genes panel sequencing of the five genes were screened using IonTorrent PGM with following Sanger confirmation. Detailed clinical evaluation of 75 unrelated BrS probands with a deep phenotyping of SCN5A (+) probands was performed. Twelve rare genetic variants (six missense, six truncating) were initially identified and classified as disease-causing. Reassessment of the clinical significance in the light of the current guidelines revealed: 2 Pathogenic (P) variants; 8 Likely Pathogenic (LP); two missense variants (p.G274S and p. S1778H) were re-classified later as a variant of uncertain significance (VUS). Unique VUS (p.Arg100Ser) was detected in the SCN4B gene. Lone Brugada-pattern was observed in 46% probands; 54% patients had concomitant arrhythmias. PR interval, the only electrocardiography parameter correlating with SCN5A-mutation, was longer (207 ± 24 ms) than normal in SCN5A (+) probands. SCD cases were registered in 31 families. Depression was the only recurring extra-cardiac complaint in SCN5A (+) probands; it was self-reported in five SCN5A (+) probands, and co-segregated with Brugada pattern in 2 families. After variants reassessment, the ratio of SCN5A (+) probands with Brugada syndrome accounts for 13% in Russian cohort.

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.

The "rSr' ECG pattern" is not always a Brugada ECG pattern

The differential diagnosis of an rSr' pattern in leads V1-V2 on the surface ECG is a common issue in daily practice. This article is protected by copyright. All rights reserved.

The Unmasking Effect: Propofol-Induced Brugada Pattern in a Critically Ill Patient

Brugada syndrome is a known cause of dysrhythmias and sudden cardiac death. It is linked to mutations in myocardial sodium channel leading to hyperexcitable cardiac myocytes. The use of this sedative has been linked to the development of inducible Brugada via blockade of sodium currents in cardiac myocytes. Although propofol is usually avoided in patients with known Brugada syndrome, some patients might have undiagnosed Brugada syndrome and thus are at risk for complications. We present a case of propofol induced Brugada in a critically ill patient.

Gene therapy targeting protein trafficking regulator MOG1 in mouse models of Brugada syndrome, arrhythmias, and mild cardiomyopathy

Brugada syndrome (BrS) is a fatal arrhythmia that causes an estimated 4% of all sudden death in high-incidence areas. SCN5A encodes cardiac sodium channel Na_V1.5 and causes 25 to 30% of BrS cases. Here, we report generation of a knock-in (KI) mouse model of BrS (Scn5a^G1746R/+). Heterozygous KI mice recapitulated some of the clinical features of BrS, including an ST segment abnormality (a prominent J wave) on electrocardiograms and development of spontaneous ventricular tachyarrhythmias (VTs), seizures, and sudden death. VTs were caused by shortened cardiac action potential duration and late phase 3 early afterdepolarizations associated with reduced sodium current density (I_Na) and increased Kcnd3 and Cacna1c expression. We developed a gene therapy using adeno-associated virus serotype 9 (AAV9) vector-mediated MOG1 delivery for up-regulation of MOG1, a chaperone that binds to Na_V1.5 and traffics it to the cell surface. MOG1 was chosen for gene therapy because the large size of the SCN5A coding sequence (6048 base pairs) exceeds the packaging capacity of AAV vectors. AAV9-MOG1 gene therapy increased cell surface expression of Na_V1.5 and ventricular I_Na, reversed up-regulation of Kcnd3 and Cacna1c expression, normalized cardiac action potential abnormalities, abolished J waves, and blocked VT in Scn5a^G1746R/+ mice. Gene therapy also rescued the phenotypes of cardiac arrhythmias and contractile dysfunction in heterozygous humanized KI mice with SCN5A mutation p.D1275N. Using a small chaperone protein may have broad implications for targeting disease-causing genes exceeding the size capacity of AAV vectors.

How Should We Approach Syncope in the Emergency Department? Current Perspectives

Syncope is a clinical picture that can affect all age groups and has an important place in admissions to the emergency department. There is an important diagnostic challenge in cases where there are different clinical presentations and patients cannot express the situation clearly. Although the emergency department facilities for the diagnosis of syncope are limited, the diagnosis of many patients can be differentiated from life-threatening conditions with a detailed history and physical examination. High-risk patients should be identified and directed for definitive treatment by emergency medicine physicians. This review contains information about the management of the syncope patient in the emergency department.

Diffuse fibrosis and repolarization disorders explain ventricular arrhythmias in Brugada syndrome: a computational study

In this work, we reported a computational study to quantitatively determine the individual contributions of three candidate arrhythmic factors associated with Brugada Syndrome. In particular, we focused our analysis on the role of structural abnormalities, dispersion of repolarization, and size of the diseased region. We developed a human phenomenological model capable of replicating the action potential characteristics both in Brugada Syndrome and in healthy conditions. Inspired by physiological observations, we employed the phenomenological model in a 2D geometry resembling the pathological RVOT coupled with healthy epicardial tissue. We assessed the insurgence of sustained reentry as a function of electrophysiological and structural abnormalities. Our computational study indicates that both structural and repolarization abnormalities are essential to induce sustained reentry. Furthermore, our results suggest that neither dispersion of repolarization nor structural abnormalities are sufficient on their own to induce sustained reentry. It should be noted how our study seems to explain an arrhythmic mechanism that unifies the classic repolarization and depolarization hypotheses of the pathophysiology of the Brugada Syndrome. Finally, we believe that this work may offer a new perspective on the computational and clinical investigation of Brugada Syndrome and its arrhythmic behaviour.

The Genetics of Brugada Syndrome

Brugada syndrome is a heritable channelopathy characterized by a peculiar electrocardiogram (ECG) pattern and increased risk of cardiac arrhythmias and sudden death. The arrhythmias originate because of an imbalance between the repolarizing and depolarizing currents that modulate the cardiac action potential. Even if an overt structural cardiomyopathy is not typical of Brugada syndrome, fibrosis and structural changes in the right ventricle contribute to a conduction slowing, which ultimately facilitates ventricular arrhythmias. Currently, Mendelian autosomal dominant transmission is detected in less than 25% of all clinical confirmed cases. Although 23 genes have been associated with the condition, only SCN5A, encoding the cardiac sodium channel, is considered clinically actionable and disease causing. The limited monogenic inheritance has pointed toward new perspectives on the possible complex genetic architecture of the disease, involving polygenic inheritance and a polygenic risk score that can influence penetrance and risk stratification. Expected final online publication date for the Annual Review of Genomics and Human Genetics, Volume 23 is October 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

A community-based study on electrocardiographic abnormalities of adult population from South India - findings from a cross sectional survey

Background

There are no data on electrocardiographic (ECG) findings from general population of Indian subcontinent. We analyzed ECG abnormalities of in adults as part of a community survey of prevalence of coronary artery disease and risk factors from South India.

Methods and results

In this cross-sectional study of men and women between the ages 20 to 79 years, ECGs recorded digitally were analyzed using the Minnesota code. Electrocardiograms were analyzed for abnormalities in 4630 participants (women 59.6%). The overall prevalence of ECG abnormalities (39.9%) was higher in men (47.24% vs. 34.9% p <0.0001). QRS axis deviation, first degree AV block, fascicular blocks, incomplete right bundle branch block, sinus bradycardia and ST elevation in the anterior chest leads were markedly higher in men. Sinus tachycardia and low voltage QRS occurred more often in women. The overall prevalence of atrial fibrillation was 0.32% which was markedly lower than the western data. Brugada and early repolarisation patterns occurred in 1.06% and 1.56% respectively, equal in both age groups, but markedly higher in men. Brugada pattern occurred more often than in the west, but much less than the Far East population. Early repolarisation pattern was similar to rest of Asian population, but significantly less than the Caucasian population

Conclusion

In this community-based study, prevalence of major electrocardiographic abnormalities was high. Overall, men had significantly higher ECG abnormalities.

Brugada-like ECG Changes After Conducted Electrical Weapon Exposure: A Case Report

Introduction

A 38-year-old with suicidal ideation and alcohol intoxication received conducted energy from a conducted energy weapon (CEW) and subsequently was found to have a transient electrocardiogram (ECG) abnormality consistent with Brugada waveform that resolved over a period of three hours.

Case Report

A 38-year-old male with no pertinent medical history presented with suicidal ideation and alcohol intoxication after an altercation with the police. The patient received two CEW exposures during an encounter with law enforcement prior to transport to the emergency department. He was asymptomatic, but an ECG was performed as part of the triage process given his reported CEW exposure. His initial ECG showed ST-segment and T-wave changes in the precordial leads similar to those found in Brugada syndrome. After a three-hour period of observation and resolution of the patient’s alcohol intoxication, a repeat ECG was performed that showed resolving Brugada morphology.

Conclusion

Review of the literature surrounding the safety profile associated with CEW exposure shows few if any documented concerning cardiac electrophysiology changes and suggests that routine electrocardiographic studies or monitoring is not required. This case presents an isolated but interesting instance of a transient ECG abnormality associated with a CEW exposure.

Pathogenesis and Management of Brugada Syndrome: Recent Advances and Protocol for Umbrella Reviews of Meta-Analyses in Major Arrhythmic Events Risk Stratification

Brugada syndrome (BrS) is a primary electrical disease associated with life-threatening arrhythmias. It is estimated to cause at least 20% of sudden cardiac deaths (SCDs) in patients with normal cardiac anatomy. In this review paper, we discuss recent advances in complex BrS pathogenesis, diagnostics, and current standard approaches to major arrhythmic events (MAEs) risk stratification. Additionally, we describe a protocol for umbrella reviews to systematically investigate clinical, electrocardiographic, electrophysiological study, programmed ventricular stimulation, and genetic factors associated with BrS, and the risk of MAEs. Our evaluation will include MAEs such as sustained ventricular tachycardia, ventricular fibrillation, appropriate implantable cardioverter–defibrillator therapy, sudden cardiac arrest, and SCDs from previous meta-analytical studies. The protocol was written following the Preferred Reporting Items for Systematic review and Meta-Analysis Protocols (PRISMA-P) guidelines. We plan to extensively search PubMed, Embase, and Scopus databases for meta-analyses concerning risk-stratification in BrS. Data will be synthesized integratively with transparency and accuracy. Heterogeneity patterns across studies will be reported. The Joanna Briggs Institute (JBI) methodology, A MeaSurement Tool to Assess systematic Reviews 2 (AMSTAR 2), and the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) are planned to be applied for design and execution of our evidence-based research. To the best of our knowledge, these will be the first umbrella reviews to critically evaluate the current state of knowledge in BrS risk stratification for life-threatening ventricular arrhythmias, and will potentially contribute towards evidence-based guidance to enhance clinical decisions.

Brugada Syndrome: Different Experimental Models and the Role of Human Cardiomyocytes From Induced Pluripotent Stem Cells

Brugada syndrome (BrS) is an inherited and rare cardiac arrhythmogenic disease associated with an increased risk of ventricular fibrillation and sudden cardiac death. Different genes have been linked to BrS. The majority of mutations are located in the SCN5A gene, and the typical abnormal ECG is an elevation of the ST segment in the right precordial leads V1 to V3. The pathophysiological mechanisms of BrS were studied in different models, including animal models, heterologous expression systems, and human-induced pluripotent stem cell-derived cardiomyocyte models. Currently, only a few BrS studies have used human-induced pluripotent stem cell-derived cardiomyocytes, most of which have focused on genotype-phenotype correlations and drug screening. The combination of new technologies, such as clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 (CRISPR associated protein 9)-mediated genome editing and 3-dimensional engineered heart tissues, has provided novel insights into the pathophysiological mechanisms of the disease and could offer opportunities to improve the diagnosis and treatment of patients with BrS. This review aimed to compare different models of BrS for a better understanding of the roles of human-induced pluripotent stem cell-derived cardiomyocytes in current BrS research and personalized medicine at a later stage.

Arrhythmogenic Right Ventricular Cardiomyopathy and Differential Diagnosis with Diseases Mimicking Its Phenotypes

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited heart muscle disease, which is characterized by fibro-fatty replacement of predominantly the right ventricle (RV). The disease can result in ventricular tachyarrhythmias and sudden cardiac death. Our understanding of the pathophysiology and clinical expressivity of ARVC has been continuously evolving. The diagnosis can be challenging due to its variable expressivity, incomplete penetrance and the lack of specific diagnostic criteria. Idiopathic RV outflow tract tachycardia, Brugada Syndrome, athlete’s heart, dilated cardiomyopathy, myocarditis, cardiac sarcoidosis, congenital aneurysms and diverticula may mimic clinical phenotypes of ARVC. This review aims to provide an update on the differential diagnosis of ARVC.

Personalized medicine in cardiovascular disease: review of literature

Purpose

Personalized medicine (PM) is the concept of managing patients based on their characteristics, including genotypes. In the field of cardiology, advantages of PM could be found in the diagnosis and treatment of several conditions such as arrhythmias and cardiomyopathies; moreover, it may be beneficial to prevent adverse drug reactions (ADR) and select the best medication. Genetic background can help us in selecting effective treatments, appropriate dose requirements, and preventive strategies in individuals with particular genotypes.

Method

In this review, we provide examples of personalized medicine based on human genetics for the most used pharmaceutics in cardiology, including warfarin, clopidogrel, and statins. We also review cardiovascular diseases, including coronary artery disease, arrhythmia, and cardiomyopathies.

Conclusion

Genetic factors are as important as environmental factors and they should be tested and evaluated more in the future by improving in genetic testing tools.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40200-021-00840-0.

Brugada ECG pattern in hypertrophic cardiomyopathy: Brugada phenocopy or overlapping syndrome?

The term phenocopy indicates a condition that imitates one produced by a gene and is also used for acquired Brugada-like ECG manifestations. Cases of Brugada phenocopies are increasingly reported in literature and an international registry is ongoing. We describe two patients with Hypertrophic Cardiomyopathy (HCM) and Brugada ECG pattern. Both patients carried the same pathogenic splicing mutation in MYBPC3 gene (responsible for HCM) while no genetic mutation associated with Brugada Syndrome was identified. To the best of our knowledge, Brugada ECG pattern has been rarely reported in patients with HCM.

The BrAID study protocol: integration of machine learning and transcriptomics for brugada syndrome recognition

BACKGROUND

Type 1 Brugada syndrome (BrS) is a hereditary arrhythmogenic disease showing peculiar electrocardiographic (ECG) patterns, characterized by ST-segment elevation in the right precordial leads, and risk of Sudden Cardiac Death (SCD). Furthermore, although various ECG patterns are described in the literature, different individual ECG may show high-grade variability, making the diagnosis problematic. The study aims to develop an innovative system for an accurate diagnosis of Type 1 BrS based on ECG pattern recognition by Machine Learning (ML) models and blood markers analysis trough transcriptomic techniques.

METHODS

The study is structured in 3 parts: (a) a retrospective study, with the first cohort of 300 anonymized ECG obtained in already diagnosed Type 1 BrS (75 spontaneous, 150 suspected) and 75 from control patients, which will be processed by ML analysis for pattern recognition; (b) a prospective study, with a cohort of 11 patients with spontaneous Type 1 BrS, 11 with drug-induced Type 1 BrS, 11 suspected BrS but negative to Na + channel blockers administration, and 11 controls, enrolled for ECG ML analysis and blood collection for transcriptomics and microvesicles analysis; (c) a validation study, with the third cohort of 100 patients (35 spontaneous and 35 drug-induced BrS, 30 controls) for ML algorithm and biomarkers testing.

DISCUSSION

The BrAID system will help clinicians improve the diagnosis of Type 1 BrS by using multiple information, reducing the time between ECG recording and final diagnosis, integrating clinical, biochemical and ECG information thus favoring a more effective use of available resources. Trial registration Clinical Trial.gov, NCT04641585. Registered 17 November 2020, https://clinicaltrials.gov/ct2/show/NCT04641585.

Prevalence and characteristics of the Brugada electrocardiogram pattern in patients with arrhythmogenic right ventricular cardiomyopathy

BACKGROUND

Despite distinct pathophysiology, arrhythmogenic right ventricular cardiomyopathy (ARVC) and Brugada syndrome (BrS) exhibit overlapping phenotypes. We investigated the prevalence and characteristics of the Brugada electrocardiogram (ECG) pattern in ARVC patients.

METHODS

A total of 114 ARVC patients fulfilling the revised Task Force Criteria were enrolled. The Brugada ECG pattern was evaluated according to the consensus report on right precordial leads, and 1141 ECGs (median, 1; interquartile range, 1-16 ECGs/patient) were analyzed.

RESULTS

Five patients (4%) showed a Brugada ECG pattern, which disappeared in four patients with ECGs recorded more than 2 years afterward. ARVC patients with the Brugada ECG pattern had a longer PQ interval (220 ± 62 ms vs 180 ± 35 ms, P = .02) and longer QRS duration (138 ± 25 ms vs 102 ± 23 ms, P < .001) than patients without the pattern. During follow-up (median, 11.4; interquartile range, 5.5-17.1 years), 19 ARVC patients experienced cardiac death and 29 experienced heart failure (HF) hospitalization. Kaplan-Meier analysis determined that the Brugada ECG pattern increased the risk of cardiac death and HF hospitalization (log-rank; P < .001, P < .001 respectively). The mean J-point and S-wave amplitudes of the Brugada ECG pattern were 0.29 ± 0.05 mV and 0.34 ± 0.21 mV, respectively, which were significantly lower than those of 26 age-matched BrS patients with a previous ventricular fibrillation episode (0.66 ± 0.33 mV, P < .001 and 0.67 ± 0.39 mV, P = .02 respectively).

CONCLUSION

The Brugada ECG pattern was infrequently encountered, was transient in ARVC patients, and was associated with a longer PQ interval, longer QRS duration, and cardiac events.

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.

Recommendations for participation in leisure-time physical activity and competitive sports of patients with arrhythmias and potentially arrhythmogenic conditions. Part 2: ventricular arrhythmias, channelopathies, and implantable defibrillators

This paper belongs to a series of recommendation documents for participation in leisure-time physical activity and competitive sports by the European Association of Preventive Cardiology (EAPC). Together with an accompanying paper on supraventricular arrhythmias, this second text deals specifically with those participants in whom some form of ventricular rhythm disorder is documented, who are diagnosed with an inherited arrhythmogenic condition, and/or who have an implanted pacemaker or cardioverter defibrillator. A companion text on recommendations in athletes with supraventricular arrhythmias is published in the European Journal of Preventive Cardiology. Since both texts focus on arrhythmias, they are the result of a collaboration between EAPC and the European Heart Rhythm Association (EHRA). The documents provide a framework for evaluating eligibility to perform sports, based on three elements, i.e. the prognostic risk of the arrhythmias when performing sports, the symptomatic impact of arrhythmias while performing sports, and the potential progression of underlying structural problems as the result of sports.

J Point and ST Elevation Resembling Brugada: A Marker of Mortality in Methanol Toxicity

Objective

J point and coved ST elevation in right precordial leads (not produced by coronary artery disease) are still a matter of challenge, especially when resembling Brugada patients. This clinical entity, among asymptomatic individuals with no family history of sudden cardiac death, would be reported in some severely ill patients before ventricular fibrillation. This study investigated the relationship between the electrocardiograms with demographic and laboratory data and also analyzed their association with mortality rate among patients with methanol poisoning.

Methods

The sample consisted of 356 patients who were hospitalized with a diagnosis of methanol poisoning in Faghihi and Namazi Hospitals in Shiraz, Southern Iran, in March and April 2020. In this period, a major outbreak of methanol poisoning had occurred in this area. Furthermore, the study used the data on any recorded complications or mortality during hospital course.

Results

The ECG (BrP) was observed in a total of 20 (5.6%) patients. Its presence was associated with increased mortality, Glasgow coma scale score <3, and blood sugar levels and was inversely associated with PH, O₂ saturation, and calcium levels (P < 0.05).

Conclusions

This study found that certain ECG patterns and laboratory data can be used as prognostic factors of morbidity and mortality in patients with methanol intoxication. Electrocardiography machines are widely available tools, which can be easily used for risk stratification based on the presence of Brugada approximating electrocardiograms among patients with methanol intoxication.

Brugada pattern in an afebrile patient with acute COVID-19

COVID-19 has been associated with significant risk for cardiac arrhythmias, particularly in patients with underlying cardiac conditions or prior histories of arrhythmia. It has been shown that a Brugada pattern can be unmasked in febrile patients with COVID-19. Herein we report a unique case of an afebrile patient without known prior history of Brugada presenting with Brugada pattern on ECG.

Transmembrane protein 168 mutation reduces cardiomyocyte cell surface expression of Nav1.5 through αB-crystallin intracellular dynamics

Transmembrane protein 168 (TMEM168) was found to be localized on the nuclear membrane. A heterozygous mutation (c.1616G>A, p. R539Q) in TMEM168 was identified in patients with Brugada syndrome. This mutation reduced expression of cardiomyocyte sodium channel Nav1.5 via Nedd4-2 E3 ubiquitin ligase-induced ubiquitination and degradation. However, the detailed molecular mechanism provoked by the TMEM168 mutant remains unclear. Here, we demonstrated that small heat shock protein αB-crystallin, which can bind to Nav1.5 and Nedd4-2 and interfere with the association of both proteins, was strongly recruited from the cell surface to the perinuclear region because of the much higher interaction of αB-crystallin with the TMEM168 mutant than with wild-type TMEM168. Following knockdown of αB-crystallin in HL-1 cardiomyocytes, the interaction of Nav1.5 with Nedd4-2 was increased, despite a reduction of the expression level of Nav1.5. Moreover, αB-crystallin-mediated reduction of Nav1.5 expression was rescued in the presence of a proteasome inhibitor MG-132, suggesting the importance of the αB-crystallin-modulated ubiquitin-proteasome system for the stability of Nav1.5 expression. Collectively, the balance of molecular interactions among Nav1.5, Nedd4-2, and αB-crystallin plays a role in the regulation of cardiomyocyte cell surface expression of Nav1.5, and the TMEM168 mutant disturbs this balance, resulting in a decrease in Nav1.5 expression.

Brugada Pattern: Unraveling Possible Cardiac Manifestation of SARS-CoV-2 Infection

We report the case of a 41-year-old patient with no family history of sudden cardiac death. The patient presented with high fever and vomiting and was diagnosed with acute pyelonephritis. Screening for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection was positive. An electrocardiogram (ECG) performed during a fever episode revealed a Brugada pattern. Fever can be a trigger for induction of the electrocardiographic Brugada pattern but it is still unknown if the cardiac involvement by coronavirus disease 2019 (COVID-19) can interfere with myocardial ion channels.

Type 2 Brugada Electrocardiogram Pattern Due to Supra-Therapeutic Phenytoin Level

Brugada syndrome (BS) is a hereditary cardiac disease leading to sudden cardiac death. It does not display any structural cardiac abnormalities. It was first described in 1992, as the syndrome of ‘right bundle branch block, persistent ST segment elevation, and sudden death.’ Brugada phenocopy (BP) is a relatively new term used to describe electrocardiogram (ECG) patterns that resemble BS but are due to other reversible causes such as electrolyte abnormalities, fever, cocaine or alcohol intoxication, and side effect of certain medications such as sodium channel blockers, beta blockers, antidepressants, alpha adrenergic blockers, etc. Earlier studies have shown that patients taking sodium channel blocking antiepileptic drugs (AEDs) especially phenytoin can have Brugada type 1 like ECG pattern. Previously, type 2 ECG pattern secondary to supra-therapeutic phenytoin level has not been described. We describe a case with type 2 Brugada ECG pattern due to supra-therapeutic phenytoin level; the ECG pattern completely resolved following lowering the phenytoin to a therapeutic level. These patients need special considerations in ED management, disposition, and follow-up.

Hyperkalemia mimicking brugada pattern in electrocardiogram: A rare case report from Nepal

Hyperkalemia is one of the dangerous complications of renal impairment (acute kidney injury or chronic kidney disease). Hyperkalemia may present with the electrocardiogram (ECG) changes as nonspecific repolarization abnormalities. Here, we report a case of AKI with hyperkalemia and the Brugada pattern of ECG, which reverted to normal after effective management of hyperkalemia. A 55-year-old male reported to the Emergency Department of National Academy of Medical Sciences (Bir Hospital) with injuries in his lower limbs and spine after he had met an accident two days back. He also had decreased urine output for the last one day. On physical examination, he had injuries in the spine and lower limbs. His laboratory investigations showed impaired renal function parameters with serum sodium 130 mEq/L and serum potassium of 7.3 mEq/L. His ECG was consistent with Brugada pattern. Patient was treated with 10% calcium gluconate, insulin and dextrose, salbutamol nebulization, and sodium polystyrene sulfonate till hemodialysis was initiated. Hyperkalemia and acidosis can manifest with the Brugada pattern in ECG. Thus, a careful evaluation of hyperkalemia and its treatment must be instituted in such an ECG pattern.