Síndrome de Brugada: 30 Anos de Aventura Científica / Brugada Syndrome: 30 Years of Scientific Ventures

Resumo 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.

Abstract 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.

Validación de escalas multiparamétricas de predicción de riesgo de muerte súbita en pacientes con síndrome de Brugada y estudio electrofisiológico / Validation of multiparametric approaches for the prediction of sudden cardiac death in patients with Brugada syndrome and electrophysiological study

Introducción y objetivos: Se han desarrollado puntuaciones multiparamétricas para una mejor estratificación del riesgo en el síndrome de Brugada (SBr). Nuestro objetivo es validar 3 abordajes multiparamétricos (las escalas Delise, Sieira y Shanghai BrS) en una cohorte de pacientes con síndrome de Brugada y estudio electrofisiológico (EEF). Métodos: Pacientes diagnosticados de SBr y con un EEF previo entre 1998-2019 en 23 hospitales. Se utilizaron análisis mediante estadístico C y modelos de regresión de riesgos proporcionales de Cox. Resultados: Se incluyó en total a 831 pacientes con una media de edad de 42,8±13,1 años; 623 (75%) eran varones; 386 (46,5%) tenían patrón electrocardiográfico (ECG) tipo 1; 677 (81,5%) estaban asintomáticos y 319 (38,4%) tenían un desfibrilador automático implantable. Durante un seguimiento de 10,2±4,7 años, 47 (5,7%) sufrieron un evento cardiovascular. En la cohorte total, un ECG tipo 1 y síncope fueron predictivos de eventos arrítmicos. Todas las puntuaciones de riesgo se asociaron significativamente con los eventos. Las capacidades discriminatorias de las 3 escalas fueron discretas (particularmente al aplicarlas a pacientes asintomáticos). La evaluación de las puntuaciones de Delise y Sieira con diferente número de extraestímulos (1 o 2 frente a 3) no mejoró sustancialmente el índice c de predicción de eventos. Conclusiones: En el SBr, los factores de riesgo clásicos como el ECG y el síncope previo predicen eventos arrítmicos. El número de extraestímulos necesarios para inducir arritmias ventriculares influye en las capacidades predictivas del EEF. Las escalas que combinan factores de riesgo clínico con EEF ayudan a identificar las poblaciones con más riesgo, aunque sus capacidades predictivas siguen siendo discretas tanto en población general con SBr como en pacientes asintomáticos (AU)

Introduction and objectives: Multiparametric scores have been designed for better risk stratification in Brugada syndrome (BrS). We aimed to validate 3 multiparametric approaches (the Delise score, Sieira score and the Shanghai BrS Score) in a cohort with Brugada syndrome and electrophysiological study (EPS). Methods: We included patients diagnosed with BrS and previous EPS between 1998 and 2019 in 23 hospitals. C-statistic analysis and Cox proportional hazard regression models were used. Results: A total of 831 patients were included (mean age, 42.8±13.1; 623 [75%] men; 386 [46.5%] had a type 1 electrocardiogram (ECG) pattern, 677 [81.5%] were asymptomatic, and 319 [38.4%] had an implantable cardioverter-defibrillator). During a follow-up of 10.2±4.7 years, 47 (5.7%) experienced a cardiovascular event. In the global cohort, a type 1 ECG and syncope were predictive of arrhythmic events. All risk scores were significantly associated with events. The discriminatory abilities of the 3 scores were modest (particularly when these scores were evaluated in asymptomatic patients). Evaluation of the Delise and Sieira scores with different numbers of extra stimuli (1 or 2 vs 3) did not substantially improve the event prediction c-index. Conclusions: In BrS, classic risk factors such as ECG pattern and previous syncope predict arrhythmic events. The predictive capabilities of the EPS are affected by the number of extra stimuli required to induce ventricular arrhythmias. Scores combining clinical risk factors with EPS help to identify the populations at highest risk, although their predictive abilities remain modest in the general BrS population and in asymptomatic patients (AU)

Brugada syndrome unmasked by fever and paradoxical lower degree of dromotropic disturbance in the right ventricular outflow tract

Brugada syndrome (BrS) is an inherited clinical-electrocardiographic arrhythmic entity with an autosomal dominant genetic pattern of inheritance or de novo variant. The syndrome has low worldwide prevalence, but is endemic in Southeast Asian countries (Thailand, Philippines and Japan). The BrS is a subtle structural heart disease (SHD), and the diagnosis is only possible when the so-called type 1 Brugada ECG pattern is spontaneously present or induced for example with fever. Repolarization-depolarization disturbances in BrS patients can be caused by genetic mutations, abnormal neural crest cell migration, low expression of connexin-43 gap junction protein, or connexome disturbances. A recent autopsy study revealed increase in biventricular collagen with myocardial fibrosis when compared with control subjects although the main affected cardiac territory is the right ventricular outflow tract (RVOT). In this location, there is abnormally low expression of significant connexin-43 gap junction responsible for the electro-vectorcardiographic manifestations of terminal QRS conduction delay in the right standard precordial leads (V1-V2), high right precordial leads (V1H-V2H), as well as in the unipolar aVR lead ("the forgotten lead"). Based on their location, these leads reflect the electrical activity of the RVOT.

A síndrome de Brugada (SBr) é uma entidade arrítmica clínico-eletrocardiográfica hereditária com padrão genético autossômico dominante de herança ou variante de novo. A síndrome tem baixa prevalência mundial, porém sendo endêmica no Sudeste Asiático (Tailândia, Filipinas e Japão). A SBr é uma doença cardíaca minimamente estrutural, sendo o diagnóstico só possível na presença do chamado padrão ECG de Brugada tipo 1 espontâneo ou induzido, por exemplo, a febre. Os distúrbios de repolarização-despolarização em pacientes com SBr podem ser causados por mutações genéticas responsáveis pela migração anormal de células da crista neural, baixa expressão "gap junctions" conexina-43 ou distúrbios do conexoma. Um estudo recente de autópsia revelou aumento do colágeno biventricular com fibrose miocárdica quando comparado aos controles, embora o principal território cardíaco afetado seja a via de saída do ventrículo direito (VSVD). Nessa área, há menor expressão da conexina-43, o que se traduz no ECG-VCG por atraso final de condução do QRS nas derivações precordiais direitas (V1-V2), precordiais direitas altas (V1H-V2H), bem como na derivação unipolar aVR ("a derivação esquecida"). Com base em sua localização, esses eletrodos refletem a atividade elétrica da VSVD

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

INTRODUCTION AND OBJECTIVES: Multiparametric scores have been designed for better risk stratification in Brugada syndrome (BrS). We aimed to validate 3 multiparametric approaches (the Delise score, Sieira score and the Shanghai BrS Score) in a cohort with Brugada syndrome and electrophysiological study (EPS). METHODS: We included patients diagnosed with BrS and previous EPS between 1998 and 2019 in 23 hospitals. C-statistic analysis and Cox proportional hazard regression models were used. RESULTS: A total of 831 patients were included (mean age, 42.8±13.1; 623 [75%] men; 386 [46.5%] had a type 1 electrocardiogram (ECG) pattern, 677 [81.5%] were asymptomatic, and 319 [38.4%] had an implantable cardioverter-defibrillator). During a follow-up of 10.2±4.7 years, 47 (5.7%) experienced a cardiovascular event. In the global cohort, a type 1 ECG and syncope were predictive of arrhythmic events. All risk scores were significantly associated with events. The discriminatory abilities of the 3 scores were modest (particularly when these scores were evaluated in asymptomatic patients). Evaluation of the Delise and Sieira scores with different numbers of extra stimuli (1 or 2 vs 3) did not substantially improve the event prediction c-index. CONCLUSIONS: In BrS, classic risk factors such as ECG pattern and previous syncope predict arrhythmic events. The predictive capabilities of the EPS are affected by the number of extra stimuli required to induce ventricular arrhythmias. Scores combining clinical risk factors with EPS help to identify the populations at highest risk, although their predictive abilities remain modest in the general BrS population and in asymptomatic patients.

Bloqueo del plano transverso abdominal para control del dolor intra y posoperatorio en herniorrafia inguinal en paciente con síndrome de Brugada / Block of transverse abdominal pain for intra-and posoperative pain control in inguinal herniorrhaphy in patient with Brugada syndrome

Los pacientes con síndrome de Brugada suponen un reto desde el punto de vista anestésico ya que son muchas las circunstancias perioperatorias y los fármacos que pueden desencadenar una crisis arritmogénica, los cuales pueden llegar a tener un fatal desenlace. Las implicaciones anestésicas en estos pacientes son múltiples por lo que se debe ser muy cuidadoso y tener en cuenta muchos factores. Se exponen las consideraciones y el manejo anestésico que se realizó en un paciente con síndrome de Brugada sometido a una herniorrafía inguinal izquierda en la que se opta por la realización de una anestesia general junto con un bloqueo ecoguiado del plano transverso abdominal para control de dolor(AU)

Patients with Brugada syndrome are a challenge from the anesthetic point of view, since there are many perioperative circumstances and drugs that can trigger an arrhythmogenic crisis, which can have a fatal outcome. Anesthetic implications in these patients are multiple, a reason why one must be very careful and take into account many factors. The considerations and anesthetic management are described for the case of a patient with Brugada syndrome who underwent left inguinal herniorrhaphy, in which general anesthesia was chosen together with ultrasound-guided block of transverse abdominal plane for pain control(AU)

Prevalência e características relacionadas de pacientes com eletrocardiograma com padrão de brugada em Santa Catarina, Brasil / Prevalence and related characteristics of patients with brugada pattern electrocardiogram in Santa Catarina, Brazil

Resumo 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.

Abstract Background: Brugada Syndrome is an inherited arrhythmogenic disorder characterized by the presence of specific electrocardiographic features with or without clinical symptoms. The patients present increased risk of sudden death due to ventricular fibrillation. The prevalence of this electrocardiographic pattern differs according to the studied region. However, epidemiological information including the Brazilian population is scarce. Objectives: To assess the prevalence of the electrocardiographic pattern of Brugada syndrome and the epidemiological profile associated with it. Methods: Cross-sectional study that included 846,533 ECG records of 716,973 patients from the electrocardiogram (ECG) database from the Santa Catarina Telemedicine Network over a 4-year period. All tests were 12-lead conventional ECG (without V1 and V2 in high positions). The tests revealing "Brugada Syndrome" diagnosis (Types 1 and 2) were reviewed by a cardiac electrophysiologist. The level of significance was set at p<0.05. Results: In total, 83 patients had a pattern potentially consistent with Brugada-type pattern ECG. Of these, 33 were confirmed having Brugada-type 1, and 22 with type 2 ECG after reevaluation. The prevalence of Brugada-type 1 ECG was 4.6 per 100,000 patients. Brugada-type 1 ECG was associated with the male gender (81.8% vs. 41.5%, p<0.001) and a lower prevalence of obesity diagnosis (9.1% vs. 26.4%, p=0.028). Conclusions: This study showed low prevalence of Brugada-type ECG in Southern Brazil. The presence of Brugada-type 1 ECG was associated with the male gender and lower prevalence of obesity diagnosis comparing to the general population.

Peculiaridade dos pacientes com arritmias hereditárias na pandemia pela COVID-19 / Peculiar aspects of patients with Inherited arrhythmias during the COVID-19 pandemic

Resumo Desde dezembro de 2019, observamos o rápido avanço da síndrome respiratória aguda grave causada pelo coronavírus 2019 (SARS-CoV-2). O impacto da evolução clínica de uma infecção respiratória é pouco conhecido em pacientes portadores de arritmias hereditárias, devido à baixa prevalência dessas doenças. Os pacientes que apresentam quadros infecciosos podem exacerbar arritmias primárias ocultas ou bem controladas, por diversos fatores, tais como febre, distúrbios eletrolíticos, interações medicamentosas, estresse adrenérgico e, eventualmente, o próprio dano miocárdico do paciente séptico. O objetivo desta revisão é destacar os principais desafios que podemos encontrar durante a pandemia pela Covid 19, especificamente nos pacientes com arritmias hereditárias, com destaque para a síndrome do QT longo congênito (SQTL), a síndrome de Brugada (SBr), a taquicardia ventricular polimórfica catecolaminérgica (TVPC) e a cardiomiopatia arritmogênica do ventrículo direito.

Abstract Since December 2019 we have observed the rapid advance of the severe acute respiratory syndrome caused by the new coronavirus (SARS-CoV-2). The impact of the clinical course of a respiratory infection is little known in patients with hereditary arrhythmias, due to the low prevalence of these diseases. Patients who present with infectious conditions may exacerbate hidden or well-controlled primary arrhythmias, due to several factors, such as fever, electrolyte disturbances, drug interactions, adrenergic stress and, eventually, the septic patient's own myocardial damage. The aim of this review is to highlight the main challenges we may encounter during the Covid 19 pandemic, specifically in patients with hereditary arrhythmias, with emphasis on the congenital long QT syndrome (LQTS), Brugada syndrome (SBr), ventricular tachycardia polymorphic catecholaminergic (CPVT) and arrhythmogenic right ventricular cardiomyopathy.

Brugada syndrome: current concepts and genetic background / Síndrome de Brugada: conceitos atuais e antecedentes genéticos

BACKGROUNG: Brugada syndrome (BrS) is a hereditary clinical-electrocardiographic arrhythmic entity with low worldwide prevalence. The syndrome is caused by changes in the structure and function of certain cardiac ion channels and reduced expression of Connexin 43 (Cx43) in the Right Ventricle (RV), predominantly in the Right Ventricular Outflow Tract (VSVD), causing electromechanical abnormalities. The diagnosis is based on the presence of spontaneous or medicated ST elevation, characterized by boost of the J point and the ST segment ≥2 mm, of superior convexity "hollow type" (subtype 1A) or descending rectilinear model (subtype 1B). BrS is associated with an increased risk of syncope, palpitations, chest pain, convulsions, difficulty in breathing (nocturnal agonal breathing) and/or Sudden Cardiac Death (SCD) secondary to PVT/VF, unexplained cardiac arrest or documented PVT/VF or Paroxysmal atrial fibrillation (AF) in the absence of apparent macroscopic or structural heart disease, electrolyte disturbance, use of certain medications or coronary heart disease and fever. In less than three decades since the discovery of Brugada syndrome, the concept of Mendelian heredity has come undone. The enormous variants and mutations found mean that we are still far from being able to concretely clarify a genotype-phenotype relationship. There is no doubt that the entity is oligogenetic, associated with environmental factors, and that there are variants of uncertain significance, especially the rare variants of the SCN5A mutation, with European or Japanese ancestors, as well as a spontaneous type 1 or induced pattern, thanks to gnomAD (coalition) researchers who seek to aggregate and harmonize exome and genome sequencing data from a variety of large-scale sequencing projects and make summary data available to the scientific community at large). Thus, we believe that this in-depth analytical study of the countless mutations attributed to BrS may constitute a real cornerstone that will help to better understand this intriguing syndrome.

INTRODUÇÃO: A Síndrome de Brugada (SBr) é uma entidade arrítmica clínico-eletrocardiográfica hereditária com baixa prevalência mundial. A síndrome é causada por alterações na estrutura e função de certos canais iônicos cardíacos e redução da expressão da Connexina 43 (Cx43) no Ventrículo Direito (VD), predominantemente no Trato de Saída do Ventricular Direito (VSVD), causando anormalidades eletromecânicas. O diagnóstico é baseado na presença de supradesnivelamento de ST espontâneo ou medicamentoso caracterizado por supradesnivelamento do ponto J e do segmento ST ≥2 mm, de convexidade superior "tipo covado" (subtipo 1A) ou modelo retilíneo descendente (subtipo 1B). A SBr está associado a um risco aumentado de síncope, palpitações, dor precordial, convulsões, dificuldade em respirar (respiração agonal noturna) e/ou Morte Cardíaca Súbita (MSC) secundária a PVT/VF, parada cardíaca inexplicada ou PVT/VF documentado ou Fibrilação atrial paroxística (FA) na ausência de doença cardíaca macroscópica ou estrutural aparente, distúrbio eletrolítico, uso de certos medicamentos ou coração coronário e febre. Em menos de três décadas desde a descoberta da síndrome de Brugada, o conceito de hereditariedade mendeliana se desfez. As enormes variantes e mutações encontradas significam que ainda estamos longe de sermos capazes de esclarecer concretamente uma relação genótipo-fenótipo. Não há dúvida de que a entidade é oligogenética associada a fatores ambientais, e que há variantes de significado incerto, principalmente as raras variantes da mutação SCN5A, com ancestrais europeus ou japoneses, bem como padrão espontâneo tipo 1 ou induzido, graças ao gnomAD (coalizão de pesquisadores que buscam agregar e harmonizar dados de sequenciamento de exoma e genoma de uma variedade de projetos de sequenciamento em grande escala e disponibilizar dados resumidos para a comunidade científica em geral). As enormes variantes e mutações encontradas significam que ainda estamos longe de sermos capazes de esclarecer concretamente uma relação genótipo-fenótipo. Assim, acreditamos que este estudo analítico em profundidade das inúmeras mutações atribuídas à BrS pode constituir uma verdadeira pedra angular que ajudará a compreender melhor esta síndrome intrigante.

Brugada syndrome: Eligibility for subcutaneous implantable cardioverter-defibrillator after exercise stress test.

INTRODUCTION: Brugada syndrome (BrS) is a channelopathy associated with ventricular arrhythmias and sudden cardiac death. In patients at high risk of sudden death, an implantable cardioverter-defibrillator is indicated. Subcutaneous implantable cardioverter-defibrillators (S-ICDs) are an alternative to transvenous systems, with reduced risk of infection and complications associated with system extraction or explantation. OBJECTIVE: To test electrocardiographic eligibility for S-ICD placement after exercise stress testing (EST) in patients with BrS. METHODS: The sample included 35 consecutive patients with BrS. Electrocardiographic eligibility was assessed using the Boston Scientific model 2889 EMBLEM™ S-ICD automated screening tool, in four phases: decubitus and orthostatism, and before and after EST. Those who had at least one acceptable vector in the four measurements were considered eligible. RESULTS: In this study, 71.4% of patients were male and mean age was 53.86±12 years. In screening prior to EST, 14.3% of patients (n=5) were not eligible for an S-ICD. There was a statistically significant association between ineligibility and presence of complete right bundle branch block and history of syncope. After EST, 16.7% of initially eligible patients no longer had eligible vectors (n=5). CONCLUSION: In this study, 16.7% of patients previously eligible for an S-ICD were no longer eligible after EST. This result demonstrates the importance of screening after EST in all patients with BrS and with indication for an S-ICD, and may influence decisions concerning which ICD to implant or whether to institute pharmacological measures that avoid inappropriate therapies.

Síndrome de brugada en el paciente quirúrgico de urgencia. Reporte de caso / Brugada syndrome in the emergency surgical patient. Case report.

Introducción: El síndrome de Brugada es una condición genética rara, el diagnóstico se establece por un patrón electrocardiográfico en particular que se asocia a un riesgo de fibrilación ventricular y muerte súbita; Objetivo: Presentar un caso interesante de un paciente joven quién ingreso a quirófano con la impresión clínica de apendicitis aguda para realizar apendicetomía video laparoscópica. Durante el procedimiento presento múltiples episodios de taquiarritmias; desencadenando Fibrilación Ventricular de difícil manejo trans y post operatorio, debido a los medicamentos peri-operatorios, agresión quirúrgica y fiebre. Material y Métodos: Se documento y presentó un caso interesante; Presentación de Caso: Paciente masculino de 26ª, sin antecedentes médicos, con impresión clínica de apendicitis aguda ingresa a quirófano, durante el acto quirúrgico presenta arritmias, documentándose Fibrilación Ventricular con inestabilidad hemodinámica que amerito desfibrilación externa, revirtió a ritmo sinusal. Al concluir el acto quirúrgico, se realiza EKG, evidenciando supradesnivel del segmento ST en V1 y V2 e inversión de la onda T por lo que pasa a unidad de cuidados intensivos, sin reversión anestésica y con tubo orotraqueal. Paciente se monitoriza en UTI, se realiza EKG evidencia ritmo nodal. Se extuba a las 12h post operatorias y se traslada a cardiología en 48h donde establecen que paciente cursa con patrón de Brugada. Conclusiones: Con el creciente número de pacientes con trastornos de conducción heredadas que se presentan para cirugía no cardiaca que están en riesgo de muerte súbita; el éxito en el manejo peri, trans y post operatorio depende de un conocimiento detallado de estas condiciones. (AU)

Introduction: Brugada syndrome is a rare genetic condition, the diagnosis is established by a particular electrocardiographic pattern and is associated with a risk of ventricular fibrillation and sudden death; Objective: To present an interesting case of a young patient who enters the operating room with the clinical impression of acute appendicitis to perform laparoscopic appendectomy and that during the procedure present multiple episodes of tachyarrhythmias; triggering Ventricular Fibrillation, what causes him difficult trans and postoperative management, due to peri-operative medications, surgical aggression and fever. Material and Methods: An interesting case was documented and presented; Case Presentation: Male patient of 26 years old, without medical history, with clinical impression of acute appendicitis was admitted to the operating room, during the surgical act it presents arrhythmias, showing Ventricular Fibrillation with hemodynamic instability that warrants external defibrillation, reversed at sinus pace, EKG is performed showing elevation gain of the ST segment in V1 and V2 and inversion of the T wave at the end of the surgical act, so it goes to intensive care unit, without anesthetic reversal and with orotracheal tube. Patient is monitored in ICU, EKG shows nodal rhythm, extubates at 12h post op and at 48h was transferred to cardiology where they establish that patient studies suggest Brugada pattern; Conclusions: With the increasing number of patients with inherited driving disorders who present the thee for non-cardiac surgery who are at risk of sudden death; success in peri, trans and postoperative management depends on a detailed knowledge of these conditions. (AU)

Síndrome de Brugada asociado a pericarditis aguda / Brugada syndrome associated to acute pericarditis

Resumen Comunicamos el caso de un hombre de 56 años que ingresó por pericarditis aguda febril, probablemente de causa viral, que durante su evolución presentó una fibrilación auricular paroxística y taquicardia ventricular polimorfa recurrente. El análisis de la historia clínica y serie electrocardiográfica permitió el diagnóstico retrospectivo asociado de un síndrome de Brugada. Hubo buena respuesta inicial al tratamiento antiinflamatorio asociado a colchicina y se implantó un desfibrilador automático intracavitario para prevención de muerte súbita. Se discuten aspectos clínicos del síndrome de Brugada, la importancia de la fiebre y de la pericarditis como cuadro clínico asociado.

Abstract A 56-year-old patient was admitted for acute febrile pericarditis, probably viral, who presented with paroxysmal atrial fibrillation and recurrent polymorphic ventricular tachycardia during his clinical course. Analysis of the clinical and electrocardiographic findings allowed the retrospective diagnosis of Brugada syndrome in the context of pericarditis. An initial response to anti-inflammatory treatment associated with colchicine was good. An internal cardioverter defibrillator was implanted to prevent sudden death. Clinical aspects of the Brugada syndrome, the importance of fever and pericarditis as an associated clinical condition are discussed.

QT interval greater than 460 ms in multiple electrocardiograms during follow-up in patients with Brugada syndrome: What does it contribute?

INTRODUCTION: Corrected QT interval (QTc) >460 ms in the right precordial leads has been described as a predictor of malignant ventricular arrhythmias (MVA) in patients with Brugada syndrome (BrS). OBJECTIVE: To assess the presence of QTc>460 ms in multiple electrocardiograms (ECGs) during follow-up as a predictor of recurrence of MVA in patients with BrS. METHODS: The study group included 43 patients with BrS and an implantable cardioverter-defibrillator. ECGs were performed serially between June 2000 and January 2017. QT interval was measured and QTc was obtained by Bazett's formula. The sample was divided into three groups: Group 1 (patients with no ECGs with QTc>460 ms); Group 2 (patients with only one ECG with QTc>460 ms); and Group 3 (patients with two or more ECGs with QTc>460 ms). RESULTS: The following variables were more frequently observed in Group 3: family history of sudden death (p=0.023), previous history of cardiorespiratory arrest (p=0.032), syncope (p=0.039), documented MVA (p=0.002), and proportion of ECGs with coved-type ST interval during follow-up (p=0.002). In Group 3, 67% of BrS patients had events during follow-up, as opposed to only 22% of Group 1 and 14% of Group 2 (Group 1 vs. Group 2, p=0.33015; Group 1 vs. Group 3, p=0.04295; and Group 2 vs. Group 3, p=0.04155). CONCLUSIONS: QTc>460 ms in more than one ECG during follow-up increases the risk of MVA events in patients with BrS.

Paro cardiorrespiratorio intraoperatorio en un paciente con síndrome de Brugada / Intraoperative cardiac arrest in a patient with Brugada síndrome

A 61-year-old female patient with history of hipertension is scheduled to undergo a minor ginecological procedure (endoscopic endometrial polipus resection) with general anesthesia. She received standard monitorization, induction with midazolam, propofol and fentanyl. Ventilated with laringeal mask. Anesthesia was maintained with sevoflurane, nitrous oxide and oxygen. During surgical procedure, the patient received atropine and ephedrine associated with two episodes of bradycardia without hemodinamic disturbances. The surgery ended without problems. During the weaking up process she presented characteristical waves of ventricular fibrillation, recuperating sinusal rhythm secondary to defibrillation with 360 J. There was no clear cause for cardiac arrest at that moment so patient was translated to the ICU for observation, monitoring and study. Postoperative EKG presented an ascending ST segment in V to V derivations without hemodynamic alterations associated. The possible diagnosis of Brugada's Syndrome was proposed. The patient received an implantable defibrillator. The mechanisms and anesthetic implications are discussed and reviewed.

Paciente de 61 años, hipertensa, fue sometida a un procedimiento endoscópico menor (histeroscopía) bajo anestesia general balanceada. Recibió monitorización estándar, inducción con midazolam, propofol y fentanilo. Se ventiló con máscara laríngea y la mantención anestésica fue con sevoflurano asociado a NO en O. En dos oportunidades recibió atropina y efedrina para el manejo de bradicardias sin compromiso hemodinámico. Se completó el procedimiento ginecológico sin complicaciones. Durante el despertar anestésico, presentó una fibrilación ventricular que cedió con desfibrilación. Se estabilizó y trasladó a UCI donde se estudió las posibles etiologías. Se obtiene ECG postoperatorio con elevación del segmento ST en derivaciones Va V sin alteraciones hemodinámicas asociadas, postulándose un síndrome de Brugada. Se le instaló desfibrilador implantable. Se revisa y discuten los diversos mecanismos e implicancias anestésicas asociadas.

Tpeak-Tend, Tpeak-Tend dispersion and Tpeak-Tend/QT in children and its relationship with clinical variables

Abstract Aim: To characterize the Tpeak-Tend, the Tpeak-Tend dispersion and Tpeak-Tend/QT in children and its relationship with clinical variables. Methods: Cross-sectional study in 126 children between 9 and 12 years of the Camilo Cienfuegos School in Santa Clara, Cuba. Clinical and anthropometric variables were obtained to determine their relationship with electrocardiographic parameters: Tpeak-Tend V5, Tpeak-Tend dispersion and Tpeak-Tend/QT ratio V5. In addition, laboratory tests were conducted. Results: Age and systolic blood pressure are associated with an increased probability of having values of Tpeak-Tend/QT V5 ≥75 percentile for both sexes (OR: 1.72, CI 95%: 1.02-2.91; p= 0.043), (OR: 1.08, CI 95%: 1.01-1.16; p= 0.017) respectively. The body mass index and systolic blood pressure are linearly and significantly correlated with the Tpeak-Tend/QT V5 (r= 0.224; p= 0.012) and (r= 0.220; p= 0.014) respectively. Conclusions: The age of the patients and the systolic blood pressure figures are factors that increase the probability of having values of the Tpeak-Tend/QT V5 ≥75 percentile. There was a significant linear correlation between the Tpeak-Tend/QT V5 with the body mass index and the systolic blood pressure.

Resumen Objetivo: Caracterizar el Tpico-Tfinal, la dispersión del Tpico-Tfinal y el Tpico-Tfinal/QT en niños y su relación con variables clínicas. Métodos: Estudio transversal en 126 niños entre 9 y 12 años de la escuela Camilo Cienfuegos en Santa Clara, Cuba. Se obtuvieron variables clínicas y antropométricas para determinar su relación con los parámetros electrocardiográficos: el Tpico-Tfinal V5, la dispersión del Tpico-Tfinal y el Tpico-Tfinal/QT V5. Además, se realizaron pruebas de laboratorio. Resultados: La edad y la presión arterial sistólica se asocian con una mayor probabilidad de tener valores del Tpico-Tfinal/QT V5 ≥75 percentil para ambos sexos (OR: 1.72, IC 95%: 1.02-2.91; p= 0.043), (OR: 1.08, IC 95%: 1.01-1.16; p= 0.017) respectivamente. El índice de masa corporal y la presión arterial sistólica están correlacionados de manera lineal y significativa con el Tpico-Tfinal/QT V5 (r= 0.224; p= 0.012) y (r= 0.220; p= 0.014) respectivamente. Conclusiones: La edad de los pacientes y las cifras de presión arterial sistólica son factores que aumentan la probabilidad de tener valores del percentil Tpico-Tfinal/QT V5 ≥75. Existe correlación lineal significativa entre el Tpico-Tfinal/QT V5 con el índice de masa corporal y la presión arterial sistólica.

Terapia ablativa en un caso de síndrome de Brugada con tormenta eléctrica / Ablative therapy in a case of Brugada syndrome with an electrical storm / Terapia ablativa em um caso de síndrome de Brugada com tempestade elétrica

Resumen: Los pacientes con síndrome de Brugada pueden presentar arritmias ventriculares malignas y muerte súbita, por lo que frecuentemente tienen indicación de implante de cardiodesfibrilador. Ocasionalmente, estos pacientes pueden tener choques recurrentes difíciles de manejar en la práctica clínica. Estudios recientes han mostrado que la ablación por radiofrecuencia en los pacientes con síndrome de Brugada es posible y efectiva.A una mujer de 55 años con síndrome de Brugada afectada por una tormenta eléctrica, se le efectuó mapeo cardíaco electroanatómico tridimensional y ablación por radiofrecuencia. Durante el estudio electrofisiológico no se observaron arritmias espontáneas o inducidas. Un mapeo de voltaje cardíaco en ritmo sinusal, precedió al uso de ablación por radiofrecuencia para modificación del sustrato arritmogénico en endocardio y epicardio del tracto de salida del ventrículo derecho. El patrón de Brugada desapareció de su electrocardiograma en el período posablativo inmediato. En cuatro meses de seguimiento la paciente no ha tenido arritmias ventriculares ni evidencia electrocardiográfica de patrón de Brugada.La modificación del sustrato arritmogénico por medio de ablación por radiofrecuencia en pacientes con síndrome de Brugada y tormenta eléctrica, puede ser de utilidad en el manejo crítico.

Summary: Patients with Brugada syndrome may have malignant ventricular arrhythmias and sudden cardiac death. Thus, these patients frequently have indication of implantable cardioverter defibrillator. Occasionally, these patients may experience recurrent appropriate cardioverter defibrillator shocks refractory to medical treatment. Recent reports indicate that radiofrequency ablation in Brugada syndrome is feasible, and effective.A 55-year-old woman with Brugada syndrome and an electrical storm, underwent three-dimensional electroanatomic mapping and radiofrequency ablation. During electrophysiological study there were no spontaneous or inducible arrhythmias. Voltage mapping of the right ventricle was created in sinus rhythm and both, endocardial and epicardial substrate modification of right ventricular outflow tract was performed. Brugada ECG pattern resolved post procedure. Follow up at 4 months revealed no recurrence of ventricular arrhythmias or Brugada electrocardiographic pattern.Radiofrequency mediated therapy for substrate modification in patients with Brugada syndrome and an electrical storm, may be useful in their critical care management.

Resumo: Os pacientes com síndrome de Brugada podem apresentar arritmias ventriculares malignas e morte súbita, de modo que frequentemente têm indicação de implante de cardiodefibrilador. Ocasionalmente, esses pacientes podem ter choques recorrentes difíceis de lidar na prática clínica. Estudos recentes mostraram que a ablação por radiofrequência em pacientes com síndrome de Brugada é possível e eficaz.Uma mulher de 55 anos com síndrome de Brugada afetada por uma tempestade elétrica apresentava mapeamento cardíaco eletroanatômico tridimensional e ablação por radiofrequência. Durante o estudo eletrofisiológico não foram observadas arritmias espontâneas ou induzidas. O mapeamento da tensão cardíaca em ritmo sinusal antecedeu o uso da ablação por radiofrequência para modificação do substrato arritmogênico no endocárdio e no epicárdio da via de saída do ventrículo direito. O padrão de Brugada desapareceu de seu eletrocardiograma no período pós-ablativo imediato. Em 4 meses de acompanhamento, o paciente não apresentou arritmias ventriculares ou evidências eletrocardiográficas do padrão de Brugada.A modificação do substrato arritmogênico por meio da ablação por radiofrequência em pacientes com síndrome de Brugada e tempestade elétrica pode ser muito útil no manejo crítico.

Post mortem genetic test, the clinical diagnosis is not fade with the death of the patient. / Teste genético post mortem, o diagnóstico clínico não se esgota com a morte do doente.

In up to one-third of cases of sudden death, the medico-legal autopsy finding is inconclusive, and the option to perform a molecular autopsy is covered in international guidelines. The importance of postmortem genetic testing lies in its ability to identify hereditary diseases, often those with an autosomal dominant transmission pattern, and, through consultations and screening of relatives, to identify family members with a pathogenic mutation, who are often asymptomatic, providing an opportunity to change the course of their lives. The authors present three clinical cases that highlight the importance of postmortem genetic studies and family studies, as well as the integration of the data obtained in a cardiology consultation, which may be for arrhythmology, coronary disease or cardiomyopathy, depending on the specific condition. This could modify the course of the disease in many relatives.

Síndrome de Brugada. Aspectos fisiopatológicos, clínicos y su asociación con enfermedades infecciosas / Brugada syndrome. Physiopathological, clinical aspects and association with infectious diseases

RESUMEN El síndrome de Brugada (SBr) es una enfermedad cardiaca no estructural que afecta los canales iónicos cardiacos, caracterizado por manifestaciones clínicas como arritmias, taquicardia, síncope y muerte súbita, entre otras. Su diagnóstico es netamente electrocardiográfico, con un patrón altamente sugestivo pero no patognomónico, por lo que existen diagnósticos diferenciales desde el punto de vista electrocardiográfico. Existen tres patrones electrocardiográficos en los pacientes con SBr, de los cuales el tipo I es el patrón más característico. Actualmente, múltiples genes se han relacionado con la presentación de este síndrome, entre los cuales se destaca el gen SCN5A, el más descrito en la literatura. Se conoce que este síndrome es más frecuente en el género masculino; sin embargo, no existen estudios epidemiológicos en Latinoamérica que lo confirmen. Pese a que la investigación alrededor de los mecanismos causales del síndrome ha avanzado, existen varias cuestiones sin resolver, como su desenmascaramiento por los signos que producen algunas enfermedades infecciosas causadas principalmente por virus. Por lo tanto, dada la relevancia clínica del tema para el médico general y para el especialista, el objetivo de esta revisión es describir no solo aspectos fisiopatológicos y clínicos de la enfermedad, sino también resaltar casos de pacientes con enfermedades infecciosas quienes posteriormente han sido diagnosticados con el síndrome de Brugada.

SUMMARY Brugada syndrome (BrS) is a non-structural cardiac disease that affects cardiac ion channels; it is characterized by clinical manifestations such as arrhythmias, tachycardia, syncope and sudden death, among others. Its diagnosis is mainly electrocardiographic, with a highly suggestive but not pathognomonic pattern, thus, there could be differential diagnoses from the electrocardiographic point of view. There are three electrocardiographic patterns in patients with BrS, of which type I is the most characteristic pattern. Currently, multiple genes have be linked to the presentation of this syndrome, among which the SCN5A gene is the most described in the literature. It is know that this syndrome is more frequent in males; however, there are not epidemiological studies in Latin America that confirm it. Although research around the causal mechanisms of the syndrome has advanced, there are several unresolved issues, for example, its unmasking by the signs produced for some infectious diseases caused mainly by viruses. Therefore, given the clinical relevance of the topic, for the medical general practitioner and the specialist, the objective of this review is to describe not only the physiopathological and clinical aspects of the disease, but also highlight cases of patients with infectious diseases, who subsequently have been diagnosed with Brugada syndrome.

Anaesthetic management of C-section in Brugada syndrome: When less is more. / Manejo anestésico del síndrome de Brugada para cesárea: cuando menos es más.

Brugada Syndrome (BrS) is a rare and high risk condition, seldom encountered in the delivery room. Pregnant patients with BrS benefit from the lowest possible doses of arrhythmogenic drugs such as local anesthetics. Based on this premise, the following case report exposes how a subarachnoid approach might be a desirable technique in C-section procedures for BrS patients. Pain and anxiety management are priorities in this specific population. Peri-partum planning, with a previous anesthesiology appointment and mutidisciplinary care in tertiary hospital facilities are crucial to avoid complications.