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2.
Eur Heart J ; 45(14): 1255-1265, 2024 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-38445836

RESUMO

BACKGROUND AND AIMS: Available data on continuous rhythm monitoring by implantable loop recorders (ILRs) in patients with Brugada syndrome (BrS) are scarce. The aim of this multi-centre study was to evaluate the diagnostic yield and clinical implication of a continuous rhythm monitoring strategy by ILRs in a large cohort of BrS patients and to assess the precise arrhythmic cause of syncopal episodes. METHODS: A total of 370 patients with BrS and ILRs (mean age 43.5 ± 15.9, 33.8% female, 74.1% symptomatic) from 18 international centers were included. Patients were followed with continuous rhythm monitoring for a median follow-up of 3 years. RESULTS: During follow-up, an arrhythmic event was recorded in 30.7% of symptomatic patients [18.6% atrial arrhythmias (AAs), 10.2% bradyarrhythmias (BAs), and 7.3% ventricular arrhythmias (VAs)]. In patients with recurrent syncope, the aetiology was arrhythmic in 22.4% (59.3% BAs, 25.0% VAs, and 15.6% AAs). The ILR led to drug therapy initiation in 11.4%, ablation procedure in 10.9%, implantation of a pacemaker in 2.5%, and a cardioverter-defibrillator in 8%. At multivariate analysis, the presence of symptoms [hazard ratio (HR) 2.5, P = .001] and age >50 years (HR 1.7, P = .016) were independent predictors of arrhythmic events, while inducibility of ventricular fibrillation at the electrophysiological study (HR 9.0, P < .001) was a predictor of VAs. CONCLUSIONS: ILR detects arrhythmic events in nearly 30% of symptomatic BrS patients, leading to appropriate therapy in 70% of them. The most commonly detected arrhythmias are AAs and BAs, while VAs are detected only in 7% of cases. Symptom status can be used to guide ILR implantation.


Assuntos
Síndrome de Brugada , Desfibriladores Implantáveis , Marca-Passo Artificial , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Arritmias Cardíacas/complicações , Arritmias Cardíacas/diagnóstico , Síndrome de Brugada/complicações , Síndrome de Brugada/diagnóstico , Síndrome de Brugada/terapia , Eletrocardiografia/métodos , Eletrocardiografia Ambulatorial/métodos , Adulto
3.
J Cardiovasc Electrophysiol ; 35(4): 701-707, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38329163

RESUMO

INTRODUCTION: Most patients with Brugada syndrome (BrS) are first diagnosed in their 40s, with sudden cardiac death (SCD) often occurring in their 50s. Ventricular fibrillation (VF) may occur in some patients with BrS despite having been asymptomatic for a long period. This study aimed to assess the incidence and risk factors for late life-threatening arrhythmias in patients with BrS. METHODS: Patients with BrS (n = 523; mean age, 51 ± 13 years; male, n = 497) were enrolled. The risk of late life-threatening arrhythmia was investigated in 225 patients who had experienced no cardiac events (CEs: SCD or ventricular tachyarrhythmia) for at least 10 years after study enrollment. The incidence of CEs during the follow-up period was examined. RESULTS: During the follow-up of the 523 patients, 59 (11%) experienced CEs. The annual incidences of CEs were 2.87%, 0.77%, and 0.09% from study enrollment to 3, 3-10, and after 10 years, respectively. Among 225 patients who had experienced no CEs for at least 10 years after enrollment, four patients (1.8%) subsequently experienced CEs. Kaplan-Meier analysis revealed significant differences in the incidence of late CEs between patients with and without a history of symptoms (p = .032). The positive and negative predictive values of late CEs for the programmed electrical stimulation (PES) test were 2.9% and 100%, respectively. CONCLUSION: Our results suggest that patients with BrS who are asymptomatic and have no ventricular tachycardia/VF inducibility by PES are at extremely low risk of experiencing late life-threatening arrhythmias.


Assuntos
Síndrome de Brugada , Humanos , Masculino , Adulto , Pessoa de Meia-Idade , Síndrome de Brugada/diagnóstico , Síndrome de Brugada/terapia , Síndrome de Brugada/complicações , Seguimentos , Japão/epidemiologia , Eletrocardiografia/métodos , Arritmias Cardíacas/complicações , Fibrilação Ventricular/diagnóstico , Fibrilação Ventricular/epidemiologia , Fibrilação Ventricular/terapia , Morte Súbita Cardíaca/epidemiologia , Morte Súbita Cardíaca/etiologia
4.
Acta Medica (Hradec Kralove) ; 66(2): 68-71, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37930096

RESUMO

Brugada syndrome (BRS) is a channelopathy with three characteristic electrocardiogram patterns and an increased risk of sudden cardiac death (SCD), in the absence of gross structural heart disease. Fever is shown to precipitate ventricular arrhythmias in patients with BRS. Here, we report a rare case of Brugada pattern in a patient with Coronavirus Disease 2019 (COVID-19) without fever. A baseline ECG should be considered for patients with COVID-19, even in the absence of fever. COVID-19 by itself may be a factor that can induce Brugada pattern ECGs.


Assuntos
Síndrome de Brugada , COVID-19 , Humanos , COVID-19/complicações , Síndrome de Brugada/complicações , Síndrome de Brugada/diagnóstico , Eletrocardiografia
5.
Europace ; 26(1)2023 12 28.
Artigo em Inglês | MEDLINE | ID: mdl-37889958

RESUMO

AIMS: The aim of this study was to investigate the outcomes of catheter ablation (CA) in preventing arrhythmic events among patients with symptomatic Brugada syndrome (BrS) who declined implantable cardioverter defibrillator (ICD) implantation. METHODS AND RESULTS: A total of 40 patients with symptomatic BrS were included in the study, of which 18 refused ICD implantation and underwent CA, while 22 patients received ICD implantation. The study employed substrate modification (including endocardial and epicardial approaches) and ventricular fibrillation (VF)-triggering pre-mature ventricular contraction (PVC) ablation strategies. The primary outcomes were a composite endpoint consisting of episodes of VF and sudden cardiac death during the follow-up period. The study population had a mean age of 43.8 ± 9.6 years, with 36 (90.0%) of them being male. All patients exhibited the typical Type 1 BrS electrocardiogram pattern, and 16 (40.0%) were carriers of an SCN5A mutation. The Shanghai risk scores were comparable between the CA and the ICD groups (7.05 ± 0.80 vs. 6.71 ± 0.86, P = 0.351). Ventricular fibrillation-triggering PVCs were ablated in 3 patients (16.7%), while VF substrates were ablated in 15 patients (83.3%). Epicardial ablation was performed in 12 patients (66.7%). During a median follow-up of 46.2 (17.5-73.7) months, the primary outcomes occurred more frequently in the ICD group than in the CA group (5.6 vs. 54.5%, Log-rank P = 0.012). CONCLUSION: Catheter ablation is an effective alternative therapy for improving arrhythmic outcomes in patients with symptomatic BrS who decline ICD implantation. Our findings support the consideration of CA as an alternative treatment option in this population.


Assuntos
Síndrome de Brugada , Ablação por Cateter , Desfibriladores Implantáveis , Humanos , Masculino , Adulto , Pessoa de Meia-Idade , Feminino , Síndrome de Brugada/complicações , Síndrome de Brugada/diagnóstico , Síndrome de Brugada/cirurgia , Fibrilação Ventricular/diagnóstico , Fibrilação Ventricular/etiologia , Fibrilação Ventricular/cirurgia , China , Eletrocardiografia , Ablação por Cateter/efeitos adversos , Ablação por Cateter/métodos
7.
J Electrocardiol ; 81: 123-131, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37688842

RESUMO

BACKGROUND: In patients with a type 2 or 3 Brugada pattern, the pharmacological (IC drugs) induction of a type 1 pattern confirms the diagnosis of Brugada syndrome. OBJECTIVE: To evaluate the value of various ECG markers in predicting IC drug test results. METHODS: We retrospectively analysed 443 consecutive patients referred to our Center (from January 2010 to December 2019) to undergo Ajmaline/Flecainide testing; all had a type 2 or 3 Brugada pattern or were relatives with Brugada syndrome. Clinical parameters and ECG markers (r1V1 and SV6 duration and amplitude, QRSV1/QRSV6 duration, V1 and V2 ST amplitude) were independently evaluated for their association to pharmacological test positivity, and a logistic regression model was applied. RESULTS: The drug test was positive in 151 (34%) patients. On multivariate logistic regression analysis, age > 45 years, female gender, HR >60 bpm, QRSV1/QRSV6 duration >1 and non-isoelectric pattern in V2 were associated with a positive test. The percentage of patients who tested positive increased according to the presence of the above ECG markers (from 11.3% in the absence to 57.6% in the presence of both factors). During long-term follow-up, the clinical event rate was higher in patients with predictive ECG markers and very low in those without. CONCLUSIONS: In our population we confirmed the ability of QRSV1/QRSV6 duration >1 and of a non-isoelectric pattern in V2 to predict a pharmacologically induced type 1 Brugada pattern. Patients with neither of these ECG markers had a rather low event rate during follow-up.


Assuntos
Síndrome de Brugada , Humanos , Feminino , Pessoa de Meia-Idade , Síndrome de Brugada/complicações , Estudos Retrospectivos , Eletrocardiografia/métodos , Ajmalina/efeitos adversos , Flecainida
8.
Europace ; 25(9)2023 08 02.
Artigo em Inglês | MEDLINE | ID: mdl-37772950

RESUMO

AIMS: Brugada syndrome (BrS) is a hereditary arrhythmic disease, associated with sudden cardiac death. To date, little is known about the psychosocial correlates and impacts associated with this disease. The aim of this study was to assess a set of patient-reported psychosocial outcomes, to better profile these patients, and to propose a tailored psychosocial care. METHODS AND RESULTS: Patients were recruited at the European reference Centre for BrS at Universitair Ziekenhuis Brussel, Belgium. Recruitment was undertaken in two phases: phase 1 (retrospective), patients with confirmed BrS, and phase 2 (prospective), patients referred for ajmaline testing who had an either positive or negative diagnosis. BrS patients were compared to controls from the general population. Two hundred and nine questionnaires were analysed (144 retrospective and 65 prospective). Collected patient-reported outcomes were on mental health (12 item General Health Questionnaire; GHQ-12), social support (Oslo Social Support Scale), health-related quality of life, presence of Type-D personality (Type-D Scale; DS14), coping styles (Brief-COPE), and personality dimensions (Ten Item Personality Inventory). Results showed higher mental distress (GHQ-12) in BrS patients (2.53 ± 3.03) than in the general population (P < 0.001) and higher prevalence (32.7%) of Type D personality (P < 0.001) in patients with confirmed Brugada syndrome (BrS +). A strong correlation was found in the BrS + group (0.611, P < 0.001) between DS14 negative affectivity subscale and mental distress (GHQ-12). CONCLUSION: Mental distress and type D personality are significantly more common in BrS patients compared to the general population. This clearly illustrates the necessity to include mental health screening and care as standard for BrS.


Assuntos
Síndrome de Brugada , Humanos , Síndrome de Brugada/diagnóstico , Síndrome de Brugada/terapia , Síndrome de Brugada/complicações , Saúde Mental , Estudos Prospectivos , Estudos Retrospectivos , Qualidade de Vida , Medidas de Resultados Relatados pelo Paciente , Eletrocardiografia/métodos
9.
J Electrocardiol ; 81: 156-158, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37734316

RESUMO

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.


Assuntos
Síndrome de Brugada , Eletrocardiografia , Humanos , Fenótipo , Síndrome de Brugada/induzido quimicamente , Síndrome de Brugada/complicações , Síndrome de Brugada/diagnóstico
10.
J Investig Med High Impact Case Rep ; 11: 23247096231201005, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37737574

RESUMO

We present a case of Brugada syndrome in a 74-year-old patient who presented with urine retention and incidentally found to have non-sustained ventricular tachycardia (NSVT) on electrocardiogram (ECG) and telemetry. To reveal characteristic type 1 Brugada pattern, right-pericardial lead was placed in the third right intercostal space. No antiarrhythmics were started, a loop recorder was implanted, and on follow-up episodes of self-terminating sustained ventricular tachycardia (VT) were noted. The patient was started on quinidine with resolution of VT.


Assuntos
Síndrome de Brugada , Taquicardia Ventricular , Humanos , Masculino , Idoso , Síndrome de Brugada/complicações , Síndrome de Brugada/diagnóstico , Taquicardia Ventricular/diagnóstico , Taquicardia Ventricular/etiologia , Antiarrítmicos/uso terapêutico , Eletrocardiografia
11.
Mol Genet Genomic Med ; 11(12): e2263, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37547970

RESUMO

BACKGROUND: Brugada syndrome (BrS) is a rare genetic disease that causes sudden cardiac death (SCD) and arrhythmia. SCN5A pathogenic variants (about 30% of diagnosed patients) are responsible for BrS. AIMS: Lack of knowledge regarding molecular characteristics and the correlation between genotype and phenotype interfere with the risk stratification and finding the optimal treatment in Vietnam. Therefore, we identified SCN5A variants and evaluated the genotype-phenotype correlation of BrS on 117 Vietnamese probands. MATERIALS AND METHODS: The clinical characteristics and blood samples of BrS patients were collected. To determine SCN5A variants, Sanger sequencing was conducted, and subsequently, these variants were analyzed by bioinformatic tools. RESULTS: In this cohort, the overall rate of detected variants in SCN5A was 25.6%, which could include both pathogenic and benign variants. In genetic testing, 21 SCN5A variants were identified, including eight novels and 15 published variants. Multiple bioinformatic tools were used to predict variant effect with c.551A>G, c.1890+14G>A, c.3338C>T, c.3578G>A, and c.5484C>T as benign, while other variants were predicted as disease-causing. The family history of SCD (risk ratio [RR] = 4.324, 95% CI: 2.290-8.269, p < 0.001), syncope (RR = 3.147, 95% CI: 1.668-5.982, p = 0.0004), and ventricular tachycardia/ventricular fibrillation (RR = 3.406, 95% CI: 1.722-5.400, p = 0.0035) presented a significantly higher risk in the SCN5A (+) group, consisting of individuals carrying any variant in the SCN5A gene, compared to SCN5A (-) individuals. CONCLUSION: The results contribute to clarifying the impact of SCN5A variants on these phenotypes. Further follow-up studies need to be carried out to understand the functional effects of these SCN5A variants on the severity of BrS.


Assuntos
Síndrome de Brugada , Humanos , Síndrome de Brugada/genética , Síndrome de Brugada/complicações , Mutação , Genótipo , Testes Genéticos , Estudos de Associação Genética , Fibrilação Ventricular , Morte Súbita Cardíaca/etiologia , Canal de Sódio Disparado por Voltagem NAV1.5/genética
12.
BMJ Case Rep ; 16(6)2023 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-37399349

RESUMO

Brugada syndrome is a rare sodium channelopathy that predisposes to an increased risk of malignant arrythmias and sudden cardiac death. Previous studies have reported that metabolic disturbances can uncover a Brugada ECG pattern. Given the risk of malignant arrhythmias, it is important to correctly diagnose and treat Brugada syndrome. We report a case of Brugada syndrome uncovered by hyperkalaemia precipitated in a patient with pseudohypoaldosteronism.


Assuntos
Síndrome de Brugada , Hiperpotassemia , Pseudo-Hipoaldosteronismo , Humanos , Síndrome de Brugada/complicações , Síndrome de Brugada/diagnóstico , Hiperpotassemia/complicações , Hiperpotassemia/diagnóstico , Pseudo-Hipoaldosteronismo/complicações , Pseudo-Hipoaldosteronismo/diagnóstico , Eletrocardiografia , Arritmias Cardíacas
13.
J Emerg Med ; 65(3): e229-e233, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37495422

RESUMO

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.


Assuntos
Fibrilação Atrial , Síndrome de Brugada , Masculino , Humanos , Procainamida/efeitos adversos , Fibrilação Atrial/complicações , China , Síndrome de Brugada/diagnóstico , Síndrome de Brugada/complicações , Morte Súbita Cardíaca/etiologia , Eletrocardiografia
14.
Heart Rhythm ; 20(10): 1358-1367, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37355026

RESUMO

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.


Assuntos
Síndrome de Brugada , Humanos , Síndrome de Brugada/complicações , Síndrome de Brugada/diagnóstico , Eletrocardiografia , China , Fatores de Risco , Medição de Risco , Morte Súbita Cardíaca/etiologia
15.
Europace ; 25(5)2023 05 19.
Artigo em Inglês | MEDLINE | ID: mdl-37129985

RESUMO

AIMS: Reduced psychological health is associated with adverse patient outcomes and higher mortality. We aimed to examine if a Brugada syndrome (BrS) diagnosis and symptomatic disease presentation were associated with an increased risk of new-onset depression or anxiety and all-cause mortality. METHODS AND RESULTS: All Danish patients diagnosed with BrS (2006-2018) with no history of psychiatric disease and available for ≥6 months follow-up were identified using nationwide registries and followed for up to 5 years after diagnosis. The development of clinical depression or anxiety was evaluated using the prescription of medication and diagnosis codes. Factors associated with developing new-onset depression or anxiety were determined using a multivariate Cox proportional hazards regression model. Disease manifestation was categorized as symptomatic (aborted cardiac arrest, ventricular tachycardia, or syncope) or asymptomatic/unspecified at diagnosis. A total of 223 patients with BrS and no history of psychiatric disease were identified (72.6% male, median age at diagnosis 46 years, 45.3% symptomatic). Of these, 15.7% (35/223) developed new-onset depression or anxiety after BrS diagnosis (median follow-up 5.0 years). A greater proportion of symptomatic patients developed new-onset depression or anxiety compared with asymptomatic patients [21/101 (20.8%) and 14/122 (11.5%), respectively, P = 0.08]. Symptomatic disease presentation (HR 3.43, 1.46-8.05) and older age (lower vs. upper tertile: HR 4.41, 1.42-13.63) were significantly associated with new-onset depression or anxiety. All-cause mortality in this group of patients treated according to guidelines was low (n = 4, 1.8%); however, 3/4 developed depression or anxiety before death. CONCLUSION: Approximately, one-sixth of patients with BrS developed new-onset depression or anxiety following a diagnosis of BrS. Symptomatic BrS disease manifestation was significantly associated with new-onset depression or anxiety.


Assuntos
Síndrome de Brugada , Humanos , Masculino , Pessoa de Meia-Idade , Feminino , Síndrome de Brugada/diagnóstico , Síndrome de Brugada/epidemiologia , Síndrome de Brugada/complicações , Depressão/diagnóstico , Depressão/epidemiologia , Morte Súbita Cardíaca/etiologia , Eletrocardiografia/métodos , Medição de Risco/métodos , Ansiedade/diagnóstico , Ansiedade/epidemiologia , Dinamarca/epidemiologia
16.
J Electrocardiol ; 80: 45-50, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37187131

RESUMO

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.


Assuntos
Síndrome de Brugada , Miocardite , Masculino , Humanos , Adulto Jovem , Adulto , Síndrome de Brugada/complicações , Síndrome de Brugada/diagnóstico , Miocardite/complicações , Miocardite/diagnóstico , Miocardite/tratamento farmacológico , Meios de Contraste , Eletrocardiografia , Gadolínio , Síncope/diagnóstico , Síncope/etiologia
17.
Circulation ; 147(21): 1622-1633, 2023 05 23.
Artigo em Inglês | MEDLINE | ID: mdl-37216437

RESUMO

Brugada syndrome (BrS), early repolarization syndrome (ERS), and idiopathic ventricular fibrillation (iVF) have long been considered primary electrical disorders associated with malignant ventricular arrhythmia and sudden cardiac death. However, recent studies have revealed the presence of subtle microstructural abnormalities of the extracellular matrix in some cases of BrS, ERS, and iVF, particularly within right ventricular subepicardial myocardium. Substrate-based ablation within this region has been shown to ameliorate the electrocardiographic phenotype and to reduce arrhythmia frequency in BrS. Patients with ERS and iVF may also exhibit low-voltage and fractionated electrograms in the ventricular subepicardial myocardium, which can be treated with ablation. A significant proportion of patients with BrS and ERS, as well as some iVF survivors, harbor pathogenic variants in the voltage-gated sodium channel gene, SCN5A, but the majority of genetic susceptibility of these disorders is likely to be polygenic. Here, we postulate that BrS, ERS, and iVF may form part of a spectrum of subtle subepicardial cardiomyopathy. We propose that impaired sodium current, along with genetic and environmental susceptibility, precipitates a reduction in epicardial conduction reserve, facilitating current-to-load mismatch at sites of structural discontinuity, giving rise to electrocardiographic changes and the arrhythmogenic substrate.


Assuntos
Síndrome de Brugada , Cardiomiopatias , Humanos , Arritmias Cardíacas , Fibrilação Ventricular/etiologia , Fibrilação Ventricular/genética , Síndrome de Brugada/complicações , Síndrome de Brugada/diagnóstico , Síndrome de Brugada/genética , Eletrocardiografia , Cardiomiopatias/diagnóstico , Cardiomiopatias/genética
18.
J Am Heart Assoc ; 12(8): e028661, 2023 04 18.
Artigo em Inglês | MEDLINE | ID: mdl-37042261

RESUMO

Background Idiopathic ventricular fibrillation (VF) is a diagnosis of exclusion following normal cardiac investigations. We sought to determine if exercise-induced changes in electrical substrate could distinguish patient groups with various ventricular arrhythmic pathophysiological conditions and identify patients susceptible to VF. Methods and Results Computed tomography and exercise testing in patients wearing a 252-electrode vest were combined to determine ventricular conduction stability between rest and peak exercise, as previously described. Using ventricular conduction stability, conduction heterogeneity in idiopathic VF survivors (n=14) was compared with those surviving VF during acute ischemia with preserved ventricular function following full revascularization (n=10), patients with benign ventricular ectopy (n=11), and patients with normal hearts, no arrhythmic history, and negative Ajmaline challenge during Brugada family screening (Brugada syndrome relatives; n=11). Activation patterns in normal subjects (Brugada syndrome relatives) are preserved following exercise, with mean ventricular conduction stability of 99.2±0.9%. Increased heterogeneity of activation occurred in the idiopathic VF survivors (ventricular conduction stability: 96.9±2.3%) compared with the other groups combined (versus 98.8±1.6%; P=0.001). All groups demonstrated periodic variation in activation heterogeneity (frequency, 0.3-1 Hz), but magnitude was greater in idiopathic VF survivors than Brugada syndrome relatives or patients with ventricular ectopy (7.6±4.1%, 2.9±2.9%, and 2.8±1.2%, respectively). The cause of this periodicity is unknown and was not replicable by introducing exercise-induced noise at comparable frequencies. Conclusions In normal subjects, ventricular activation patterns change little with exercise. In contrast, patients with susceptibility to VF experience activation heterogeneity following exercise that requires further investigation as a testable manifestation of underlying myocardial abnormalities otherwise silent during routine testing.


Assuntos
Síndrome de Brugada , Complexos Ventriculares Prematuros , Humanos , Síndrome de Brugada/complicações , Síndrome de Brugada/diagnóstico , Sistema de Condução Cardíaco , Complexos Ventriculares Prematuros/etiologia , Complexos Ventriculares Prematuros/complicações , Eletrocardiografia , Fibrilação Ventricular/diagnóstico , Fibrilação Ventricular/etiologia , Sobreviventes
20.
Arq Bras Cardiol ; 120(3): e20220289, 2023 03.
Artigo em Inglês, Português | MEDLINE | ID: mdl-36946855

RESUMO

Thirty years ago, a distinctly new clinical-electrocardiographic syndrome was described, today known as Brugada Syndrome (BrS). Typical treatment for this type of syndrome is electrocardiography with ST-segment elevation in the direct precordial derivations. The clinical presentation of the disease is highly variable: the patients can remain completely asymptomatic, but they can also develop episodes of syncope, atrial fibrillation (AF), sinus node dysfunction (SNF), conduction disorders, asystole, and ventricular fibrillation (VF). This disease is caused by mutations in the genes responsible for the potential action of cardiac cells. The most commonly involved gene is SCN5A, which controls the structure and function of the heart's sodium channel. The description of this new syndrome has shown highly positive implications in all fields of medicine.


Trinta anos atrás, uma nova síndrome clínico-eletrocardiográfica distinta foi descrita, agora conhecida como síndrome de Brugada (SBr). Típico para essa síndrome é o eletrocardiograma com supradesnivelamento do segmento ST nas derivações precordiais direitas. A apresentação clínica da doença é altamente variável: os pacientes podem permanecer completamente assintomáticos, mas também podem desenvolver episódios de síncope, fibrilação atrial (FA), síndrome do nódulo sinusal (SNS), distúrbios de condução, assistolia e fibrilação ventricular (FV). A doença é causada por mutações nos genes responsáveis pelo potencial de ação das células do coração. O gene mais frequentemente envolvido é o SCN5A, que controla a estrutura e função do canal de sódio cardíaco. A descrição dessa nova síndrome teve implicações muito positivas em todos os campos da medicina.


Assuntos
Fibrilação Atrial , Síndrome de Brugada , Humanos , Síndrome de Brugada/diagnóstico , Síndrome de Brugada/genética , Síndrome de Brugada/complicações , Doença do Sistema de Condução Cardíaco/complicações , Fibrilação Atrial/diagnóstico , Fibrilação Atrial/genética , Fibrilação Atrial/complicações , Eletrocardiografia , Fibrilação Ventricular , Canal de Sódio Disparado por Voltagem NAV1.5/genética
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