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Resumo A artéria do cone (AC) irriga a via de saída do ventrículo direito (VSVD). A elevação do segmento ST nas derivações V1-3, que pode assemelhar-se aos padrões de eletrocardiograma (ECG) de Brugada, foi relatada devido à oclusão da AC. Um paciente do sexo masculino, 68 anos de idade, foi internado no hospital com diagnóstico de infarto do miocárdio sem supradesnivelamento do segmento ST. Uma angiografia coronária revelou uma dissecção na AC, provavelmente causada pelo cateter. Devido ao pequeno calibre da AC, a terapia medicamentosa foi escolhida como curso de ação. No entanto, após o procedimento, um ECG mostrou alterações consistentes com características dos padrões de Brugada tipo 1 e tipo 2, com elevações do segmento ST nas derivações V1-4. A imagem coronariana subsequente revelou que a AC havia progredido para oclusão total. Apesar das diversas tentativas de obter a reentrada no lúmen verdadeiro, não houve êxito. Com base na relação risco-benefício, foi tomada a decisão de continuar com a terapia medicamentosa. Este é o primeiro caso relatado de oclusão da AC induzida por dissecção por cateter, que se manifesta como elevação ântero-septal do segmento ST. O paciente não relatou sintomas anginosos ou eventos arrítmicos, o que contrasta com o conhecimento convencional. Nem todas as obstruções da AC ou infartos da VSVD causam padrões semelhantes aos de Brugada. Quando isso ocorre, as elevações de ST tendem a ser menores do que as da verdadeira síndrome de Brugada.

Abstract The conus artery (CA) supplies the right ventricular outflow tract (RVOT). ST-segment elevation in leads V1-3, which can resemble Brugada electrocardiogram (EKG) patterns, has been reported due to occlusion of the CA. A 68-year-old male was admitted to the hospital with a diagnosis of non-ST-elevation myocardial infarction. A coronary angiogram revealed a dissection in the conus artery, most likely caused by the catheter. Due to the small caliber of the CA, medical therapy was chosen as the course of action. However, after the procedure, an EKG showed changes consistent with features of both type-1 and type-2 Brugada patterns, with ST-segment elevations in leads V1-4. Subsequent coronary imaging revealed that the CA had progressed to total occlusion. Despite multiple attempts to gain reentry into the true lumen, they were unsuccessful. Based on the risk-benefit ratio, the decision was made to continue with medical therapy. This is the first reported case of CA occlusion induced by catheter dissection, which manifested as anteroseptal ST-segment elevation. The patient did not report any anginal symptoms or arrhythmic events, which contrasts with conventional knowledge. Not all CA obstructions or RVOT infarcts cause Brugada-like patterns. When they do, ST elevations tend to be less than those in true Brugada syndrome.

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AIMS: High precordial leads (HPL) on the resting electrocardiogram (ECG) are widely used to improve diagnostic detection of type 1 Brugada ECG pattern (Br1ECGp). A parasympathetic activation marks the initial recovery phase of treadmill stress testing (TET), and this can be useful for detecting the typical ECG pattern. Our study aimed to evaluate the role of a new HPL-treadmill exercise testing (TET) protocol in detecting Br1ECGp fluctuation compared to resting HPL-ECG. METHODS AND RESULTS: 74 out of 163 patients of a Brugada syndrome (BrS) Brazilian cohort (GenBra Registry) underwent exercise testing with HPL-TET protocol. Precordial leads were displayed in strategic positions in the right and left parasternal spaces. The step-by-step analysis included ECG classification (as presence or absence of Br1ECGp) in standard vs. HPL leads placement in the following sequences: resting phase, maximal exercise, and the passive recovery phase (including 'quick lay down'). For heart rate recovery (HRR) measurements and comparisons, a Student's t-test was applied. McNemar tests compared the detection of Br1ECGp. The significance level was defined as P < 0.05. Fifty-seven patients (57/74; 77%) were male, the mean age was 49.0 ± 14, 78.4% had spontaneous BrS, and the mean Shanghai score was 4.5. The HPL-TET protocol increased Br1ECGp detection by 32.4% against resting HPL-ECG (52.7% vs. 20.3%, P = 0.001) alone. CONCLUSION: Stress testing using HPL with the passive recovery phase in the supine position offers an opportunity to unmask the type 1 Br1ECGp, which could increase the diagnostic yield in this population.

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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.

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Abstract Brugada syndrome (BS) is a genetic channelopathy, clinically characterized by an increased risk of sudden cardiac death. The diagnosis requires a typical electrocardiographic pattern, and data on risk stratification are limited in the literature. The aim of this study was to conduct a review on the importance of exercise stress test (EST) in risk stratification in BS. Articles were searched in the PubMed, Scielo and Google Scholar databases. From the 200 articles retrieved, eight were included, with a total of 712 patients (95% men) aged between 35 and 60 years. Severe symptoms and ventricular arrhythmias were reported by 256 patients before the EST, with syncope being reported in 70% of cases. The reviewed articles suggest that the EST is a safe method that can help in the diagnosis and risk stratification for malignant arrhythmias in patients with BS. Potential predictors of poor prognosis were: augmentation in ST-segment elevation > 0.5 mV in V1, V2 or V3 in early recovery; J-point elevation in lead > 2mm in aVR in late recovery; heart rate reduction < 40% from maximum heart rate in late recovery and occurrence of ventricular extrasystoles in early recovery.

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BACKGROUND: Clinical and molecular diagnosis of inherited cardiac conditions is key to find at-risk subjects and avoid preventable deaths. This study aimed to identify genetic variants in a sample of Colombian patients diagnosed with inherited cardiac conditions. METHODS: Next-generation sequencing (Illumina platform) using a 231 gene panel was performed in blood samples of 25 unrelated patients with age disease onset between 9 and 55 years. RESULTS: Genetic testing yield was 52%. Two novel likely pathogenic/ pathogenic variants were found: a DSP nonsense variant in a patient with arrhythmogenic cardiomyopathy and a KCNE1 frameshift variant in two patients with long QT syndrome. Younger individuals (<18 years) had the highest genetic testing yield (66.6%) compared to 50% and 20% in young adults and patients over 40 years, respectively. All subjects affected with long QT syndrome with a severe event while exercising had a positive genetic test. They also had four times more loss of consciousness events and, resuscitated sudden cardiac arrest was more representative. CONCLUSION: This study is the first one undertaken in Colombia to evaluate inherited cardiac conditions. It highlights the need to perform mutational analysis to provide adequate genetic counseling and to be able to identify patients at risk of severe events.

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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

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The current pandemic caused by the coronavirus disease 2019 (COVID-19) continues affecting millions of people worldwide. Various cardiovascular manifestations have been associated with COVID-19 but only a few case reports of Brugada syndrome in acute respiratory syndrome by SARS-CoV-2 were published. The diagnosis, prognosis, and treatment remain a challenge and represent a concern in terms of management in this population. We describe a case of a 66-year-old patient with COVID-19 presenting a coved type-1 Brugada pattern in electrocardiogram. Drug challenge was performed for the diagnosis of Brugada syndrome and electrophysiological study for risk stratification. .