Brugada Syndrome as an Underlying Diagnosis for a Prehospital Seizure Dispatch

Brugada syndrome is an inherited genetic disorder known to cause a variety of patient complaints but may ultimately cause ventricular fibrillation and sudden cardiac death. We present a patient with witnessed seizure who was ultimately diagnosed with Brugada syndrome. Multiple ventricular arrhythmias complicated the case, which was managed in- and out-of-hospital.

Brugada syndrome and job fitness: report of three cases

Brugada syndrome (BrS) is an inherited arrhythmogenic disorder predisposing patients to a high risk of sudden cardiac death. Specific guidelines on the health surveillance of BrS workers are lacking. We report here three cases requiring assessment of specific job capacity, investigated with an interdisciplinary protocol including 24-h Holter electrocardiography with modified precordial leads, pharmacological test with ajmaline, molecular genetic analysis, electrophysiological study with ventricular stimulation, risk stratification, and occupational medicine evaluation: (1) a female 42-yr-old company manager with positive ajmaline test and CACNA1C gene mutation (judged fit for the job with limitations regarding work-related stress); (2) a male 44-yr-old welder with positive ajmaline test, SCN5A gene mutation, and associated OSAS (obstructive sleep apnea syndrome), who was advised to refrain from night shifts and driving company vehicles; (3) a male 45-yr-old electrical technician with inducible ventricular tachyarrhythmia, who was implanted with a biventricular cardioverter defibrillator, and therefore recommended to avoid exposure to electromagnetic fields and working at heights. We conclude that the collaboration between the cardiologist and the occupational physician allows defining the functional capabilities and the arrhythmogenic risk of BrS workers, to optimize job fitness assessment.

SCN5A mutation is associated with a higher Shanghai Score in patients with type 1 Brugada ECG pattern

AIMS

Brugada syndrome (BrS) is an inherited arrhythmic disease characterized by a coved ST-segment elevation in the right precordial electrocardiogram leads (type 1 ECG pattern) and is associated with a risk of malignant ventricular arrhythmias and sudden cardiac death. In order to assess the predictive value of the Shanghai Score System for the presence of a SCN5A mutation in clinical practice, we studied a cohort of 125 patients with spontaneous or fever/drug-induced BrS type 1 ECG pattern, variably associated with symptoms and a positive family history.

METHODS

The Shanghai Score System items were collected for each patient and PR and QRS complex intervals were measured. Patients were genotyped through a next-generation sequencing (NGS) custom panel for the presence of SCN5A mutations and the common SCN5A polymorphism (H558R).

RESULTS

The total Shanghai Score was higher in SCN5A+ patients than in SCN5A- patients. The 81% of SCN5A+ patients and the 100% of patients with a SCN5A truncating variant exhibit a spontaneous type 1 ECG pattern. A significant increase in PR (P = 0.006) and QRS (P = 0.02) was detected in the SCN5A+ group. The presence of the common H558R polymorphism did not significantly correlate with any of the items of the Shanghai Score, nor with the total score of the system.

CONCLUSION

Data from our study suggest the usefulness of Shanghai Score collection in clinical practice in order to maximize genetic test appropriateness. Our data further highlight SCN5A mutations as a cause of conduction impairment in BrS patients.

Efficacy and safety of catheter ablation for Brugada syndrome: an updated systematic review

BACKGROUND

Patients with Brugada syndrome (BrS) may experience recurrent ventricular arrhythmias (VAs). Catheter ablation is becoming an emerging paradigm for treatment of BrS.

OBJECTIVE

To assess the efficacy and safety of catheter ablation in BrS in an updated systematic review.

METHODS

We comprehensively searched the databases of Pubmed/Medline, EMBASE, and Cochrane Central Register of Controlled Trials from inception to 11th of August 2021.

RESULTS

Fifty-six studies involving 388 patients were included. A substrate-based strategy was used in 338 cases (87%), and a strategy of targeting premature ventricular complex (PVCs)/ventricular tachycardias (VTs) that triggered ventricular fibrillation (VF) in 47 cases (12%), with combined abnormal electrogram and PVC/VT ablation in 3 cases (1%). Sodium channel blocker was frequently used to augment the arrhythmogenic substrate in 309/388 cases (80%), which included a variety of agents, of which ajmaline was most commonly used. After ablation procedure, the pooled incidence of non-inducibility of VA was 87.1% (95% confidence interval [CI], 73.4-94.3; I2 = 51%), and acute resolution of type I ECG was seen in 74.5% (95% CI [52.3-88.6]; I2 = 75%). Over a weighted mean follow up of 28 months, 7.6% (95% CI [2.1-24]; I2 = 67%) had recurrence of type I ECG either spontaneously or with drug challenge and 17.6% (95% CI [10.2-28.6]; I2 = 60%) had recurrence of VA.

CONCLUSION

Catheter ablation appears to be an efficacious strategy for elimination of arrhythmias or substrate associated with BrS. Further study is needed to identify which patients stand to benefit, and optimal provocation protocol for identifying ablation targets.

Challenges in Brugada Syndrome Stratification: Investigating SCN5A Mutation Localization and Clinical Phenotypes

Brugada Syndrome (BrS) is a genetic heart condition linked to sudden cardiac death. Though the SCN5A gene is primarily associated with BrS, there is a lack of comprehensive studies exploring the connection between SCN5A mutation locations and the clinical presentations of the syndrome. This study aimed to address this gap and gain further understanding of the syndrome. The investigation classified 36 high-risk BrS patients based on SCN5A mutations within the transmembrane/structured (TD) and intra-domain loops (IDLs) lacking a 3D structure. We characterized the intrinsically disordered regions (IDRs) abundant in IDLs, using bioinformatics tools to predict IDRs and post-translational modifications (PTMs) in NaV1.5. Interestingly, it was found that current predictive tools often underestimate the impacts of mutations in IDLs and disordered regions. Moreover, patients with SCN5A mutations confined to IDL regions-previously deemed 'benign'-displayed clinical symptoms similar to those carrying 'damaging' variants. Our research illuminates the difficulty in stratifying patients based on SCN5A mutation locations, emphasizing the vital role of IDLs in the NaV1.5 channel's functioning and protein interactions. We advocate for caution when using predictive tools for mutation evaluation in these regions and call for the development of improved strategies in accurately assessing BrS risk.

Brugada phenocopy associated with multiple psychotic drugs

Brugada phenocopy (BrP) is a clinical condition characterized by transient ECG changes of Brugada syndrome (BrS), which can be due to various clinical conditions. We describe a case report of BrP due to psychotic drugs.

Characterisation and long-term follow-up of children with Brugada syndrome: experience from a tertiary paediatric referral centre

AIMS

Brugada syndrome is an inherited condition, which typically presents in young adults. It can also be diagnosed in children, but data in this group remain scarce. This study aims to describe the clinical features, management, and follow-up of children with personal or family history of Brugada syndrome.

METHODS

Retrospective study of consecutive patients with Brugada history followed up in a tertiary paediatric referral centre between 2009 and 2021. Patients were assessed according to the phenotype: positive (with variable genotype) or negative (with positive genotype).

RESULTS

Thirty patients were included (mean age at diagnosis 7 ± 6 years, 53% male). Within the positive phenotype (n = 16), 81% were male, and 88% had spontaneous type 1 ECG pattern. A genetic test was performed in 88% and was positive in 57%. Fourteen patients had a negative phenotype-positive genotype, 79% female, all diagnosed during family screening; 43% mentioned family history of sudden cardiac death. Although most of the patients were asymptomatic, the prevalence of rhythm/conduction disturbances was not negligible, particularly if a positive phenotype. No clinically significant events were reported in the negative phenotype patients. Three patients were hospitalised due to an arrhythmic cause, all in patients with a positive phenotype.

CONCLUSION

In our study, the documentation of rhythm and conduction disturbances was not infrequent, especially in patients with a positive phenotype. Despite the significant family history, phenotype negative patients had no relevant events during follow-up. Nevertheless, the management of these patients is not clear cut, and a personalised therapeutic strategy with close follow-up is essential.

Left Ventricular Abnormal Substrate in Brugada Syndrome

BACKGROUND

Slow-conductive structural abnormalities located in the epicardium of the right ventricle (RV) underlie Brugada syndrome (BrS). The extent of such substrate in the left ventricle (LV) has not been investigated.

OBJECTIVES

This study sought to characterize the extent of epicardial substrate abnormalities in BrS.

METHODS

We evaluated 22 consecutive patients (mean age 46 ± 11 years, 21 male) referred for recurrent ventricular arrhythmias (mean 10 ± 13 episodes) in the setting of BrS. The patients underwent clinical investigations and wide genetic screening to identify SCN5A mutations and common risk variants. High-density biventricular epicardial mapping was performed to detect prolonged (>70 ms) fragmented electrograms, indicating abnormal substrate area.

RESULTS

All patients presented with abnormal substrate in the epicardial anterior RV (27 ± 11 cm2). Abnormal substrate was also identified on the LV epicardium in 10 patients (45%), 9 at baseline and 1 after ajmaline infusion, covering 15 ± 11 cm2. Of these, 4 had severe LV fascicular blocks. Patients with LV substrate had a longer history of arrhythmia (11.4 ± 6.7 years vs 4.3 ± 4.3 years; P = 0.003), longer PR (217 ± 24 ms vs 171 ± 14 ms; P < 0.001) and HV (60 ± 12 ms vs 46 ± 5 ms; P = 0.005) intervals, and abnormal substrate also extending into the inferior RV (100% vs 33%; P = 0.001). SCN5A mutation was present in 70% of patients with LV substrate (vs 25%; P = 0.035). SCN5A BrS patients with recurrent ventricular arrhythmias present a higher polygenic risk score compared with a nonselected BrS population (median of differences: -0.86; 95% CI: -1.48 to -0.27; P = 0.02).

CONCLUSIONS

A subset of patients with BrS present an abnormal substrate extending onto the LV epicardium and inferior RV that is associated with SCN5A mutations and multigenic variants.

Predicting arrhythmic event score in Brugada syndrome: Worldwide pooled analysis with internal and external validation

BACKGROUND

Brugada syndrome is an inherited arrhythmic disease associated with major arrhythmic events (MAE). Risk predictive scores were previously developed with various performances.

OBJECTIVE

The purpose of this study was to create a novel score-Predicting Arrhythmic evenT (PAT)-with internal and external validation.

METHODS

A systematic review was performed to identify risk factors for MAE. The odds ratios (ORs) of each factor were pooled across studies. The PAT scoring scheme was developed based on pooled ORs. The PAT score was internally validated with published 105 Asian patients (follow-up 8.0 ± 4.1 [SD] years) and externally validated with unpublished 164 multiracial patients (82.3% White, 14.6% Asian, 3.2% Black; mean follow-up 8.0 ± 6.9 years) with Brugada syndrome. Performances were assessed and compared with previous scores using receiver operating characteristic curve (ROC) analysis.

RESULTS

Sixty-seven studies published between 2002 and 2022 from 26 countries (7358 patients) were included. Pooled ORs were estimated, indicating that 15 of 23 risk factors were significant. The PAT score was then developed accordingly. The PAT score had significantly better discrimination (ROC 0.9671) than the BRUGADA-RISK score (ROC 0.7210; P = .006), Shanghai Score System (ROC 0.7079; P = .003), and Sieira et al score (ROC 0.8174; P = .026) in an external validation cohort. PAT score ≥ 10 predicted the first MAE with 95.5% sensitivity and 89.1% specificity (ROC 0.9460) and the recurrent MAE (ROC 0.7061) with 15.4% sensitivity and 93.3% specificity.

CONCLUSION

The PAT score was shown to be useful in predicting MAE for primary prevention in patients with Brugada syndrome.

Histopathological characteristics of the arrhythmogenic right ventricular cardiomyopathy presenting the electrocardiographic characteristics with Brugada syndrome

INTRODUCTION

The histopathological characteristics of the overlapping disease states of Brugada syndrome (BrS) and arrhythmogenic right ventricular cardiomyopathy (ARVC) have not been fully elucidated.

METHODS

A 71-year-old man showed coved-type ST-segment elevation with the right precordial leads, and the echocardiography demonstrated right ventricular (RV) dilatation. After 11 months, he died of a polymorphic VT storm.

RESULTS

The pathological tissue demonstrated fibrofatty degeneration in the free wall of the RV outflow tract based on the heart autopsy.

CONCLUSION

The overlapping disease states of BrS and ARVC showed histopathological characteristics consistent with ARVC.

Diagnostic and therapeutic dilemmas in a patient with myocarditis, Brugada syndrome and arrhythmic syncope

We present a case of a previously healthy 23-year-old male who presented with chest pain, palpitations and spontaneous type 1 Brugada electrocardiographic (ECG) pattern. Positive family history for sudden cardiac death (SCD) was remarkable. Initially, clinical symptoms in combination with myocardial enzymes elevation, regional myocardial oedema with late gadolinium enhancement (LGE) on cardiac magnetic resonance (CMR) and inflammatory lymphocytoid-cell infiltrates in the endomyocardial biopsy (EMB) suggested the diagnosis of a myocarditis-induced Brugada phenocopy (BrP). Under immunosuppressive therapy with methylprednisolone and azathioprine, a complete remission of both symptoms and biomarkers was accomplished. However, the Brugada pattern did not resolve. The eventually spontaneous Brugada pattern type 1 established the diagnosis of Brugada syndrome (BrS). Due to his previous history of syncope, the patient was offered an ICD that he declined. After his discharge he experienced a new episode of arrhythmic syncope. He was readmitted and received an ICD.

Procainamide-Provoked Brugada Pattern in a Patient Presenting with New-Onset Atrial Fibrillation or Flutter: When Does it Matter?

BACKGROUND

Brugada syndrome (BrS) is an inherited disease that can lead to sudden cardiac death. Medications, such as antidysrhythmics, and fevers can unmask or induce the Brugada pattern on an electrocardiogram (ECG). This case report highlights a patient who developed drug-induced Brugada type I pattern after a procainamide infusion for the treatment of new-onset atrial fibrillation (AF) or flutter and discusses the implications for this incidental but potentially lethal finding.

CASE REPORT

We report a case of a young man who presented to the emergency department (ED) with new-onset AF with rapid ventricular response that began within 12 h of presentation. ED treatments included a crystalloid IV fluid bolus, diltiazem pushes, synchronized electrical cardioversion, and a procainamide infusion. After the procainamide infusion, the patient developed ECG findings consistent with Brugada pattern. Both the AF and Brugada pattern resolved spontaneously within 24 h. The patient was discharged without implantable cardioverter defibrillator placement due to presumed isolated procainamide-induced Brugada pattern and lack of concerning features, such as inducible dysrhythmia during electrophysiology study, family history of sudden death, and history of syncope. The patient was counseled to follow-up with genetics and avoid BrS-inducing medications. WHY SHOULD AN EMERGENCY PHYSICIANS BE AWARE OF THIS?: Procainamide, an option for the treatment of AF in the ED, can provoke Brugada pattern. If encountered, it is important to recall that some patients may not be diagnosed with BrS if determined to be low risk according to the Shanghai criteria. All patients should be referred to cardiology for further evaluation.