Research Progress of Exosomal microRNA in Cardiovascular Disease and Its Forensic Application Prospects / 法医学杂志

Exosomal microRNAs (miRNAs) are miRNAs that are mediated by exosomes to achieve cell-to-cell communication, and they are widespread in organisms. In recent years, the key role of the multiple biological functions of exosomal miRNAs in the occurrence and development of cardiovascular diseases has been confirmed by a large number of studies, which has become a hot spot in clinical and basic research. Sudden cardiac death caused by cardiovascular disease is one of the important contents in forensic medical identification. This article introduces the research progress of cardiovascular disease prediction, treatment and prognosis on exosomal miRNA. The prospects of the application in forensic medical identification are discussed.

Genetic study of cardiovascular disease subtypes defined by International Classification of Diseases / 北京大学学报(医学版)

OBJECTIVE@#To study the molecular connection among cardiovascular diseases (CVD) subtypes defined by the International Classification of Diseases (ICD) version 10 (ICD-10).@*METHODS@#Both phenotypic data and genotypic data used in this study were obtained from the UK Biobank. A total of 380 083 participants aged between 40 and 69 years were included. Those without any cardiovascular disease (either no ICD-10 code at all or no ICD-10 code containing letter I) were assigned to the control group. The five CVD subtypes were: ischaemic heart diseases (IHD), pulmonary heart disease and diseases of pulmonary circulation (PHD), cerebrovascular diseases (CRB), diseases of arteries, arterioles and capillaries (AAC), diseases of veins, lymphatic vessels and lymph nodes, and diseases not elsewhere classified (VLL). We first performed a genome-wide association study (GWAS) for each of the five subtypes. We summarized novel loci using genome-wide significance threshold P=5×10-8. Next, we used linkage disequilibrium score regression (LDSC) method to assess genetic correlation among the five subtypes. Lastly, we applied mendelian randomization (MR) approach to assess the causal relationship among the subtypes. The particular software that we used was generalised summary-data-based mendelian randomisation (GSMR).@*RESULTS@#Through GWAS, we identified hundreds of genome-wide significant SNPs: 672 for IHD, 241 for PHD, 31 for CRB, 48 for AAC, and 193 for VLL. By comparing with published literature, we found 28 novel loci, for PHD (n=14), CRB (n =7) and AAC (n =7). Eight of these 28 loci were rare, where the lead SNP had minor allele frequency (MAF) less than 1%. LDSC analyses indicated IHD had significant genetic correlation with VLL (P=2.52×10-7), PHD (P=3.77×10-3) and AAC (P=4.90×10-3), respectively. Bidrectional GSMR analyses showed that IHD had a positive causal relationship with VLL (P=7.40×10-5) and AAC (P=1.50×10-3), while reverse causality was not supported.@*CONCLUSION@#This study adopted an innovative approach to study the molecular connection among CVD subtypes that are defined by ICD. We identified potentially positive genetic correlation and causal effects among some of these subtypes. Research along this line will provide scientific insights and serve as a guidance for future ICD standards.

Associação de Fatores de Risco Cardiovascular e Polimorfismo de APOE com Mortalidade em Idosos Longevos: Uma Coorte de 21 Anos / Association of Cardiovascular Risk Factors and APOE Polymorphism with Mortality in the Oldest Old: A 21-Year Cohort Study

Resumo Fundamento: O conhecimento dos fatores ambientais e genéticos para um envelhecimento bem-sucedido em idosos longevos é controverso. Acrescenta-se a esta evidência, o fato de serem poucos os estudos delineados com essa população. Objetivo: Investigar a relação entre os genótipos mais frequentes da apolipoproteína E (APOE) e a mortalidade em idosos longevos que vivem em comunidade e sua sobrevida de acordo com os fatores de risco cardiovascular. Métodos: Uma amostra de 74 idosos com 80 anos ou mais da coorte do Projeto Veranópolis foi selecionada para genotipagem da APOE. Na linha de base, foram coletadas variáveis antropométricas, dosagens sanguíneas de glicose e lipídeos, pressão arterial e variáveis de estilo de vida (tabagismo, consumo de álcool e atividade física). A escala Bayer de Atividades da Vida Diária foi aplicada aos cuidadores dos idosos. O tempo de seguimento total do estudo foi 21 anos. Um p<0,05 bicaudal foi considerado estatisticamente significativo. Resultados: Não encontramos associação entre os genótipos da APOE e mortalidade. Entretanto, o risco de morte em idosos fumantes foi 2,30 vezes (hazard ratio [HR]; intervalo de confiança de 95% [IC 95%] 1,01 a 5,24); em diabéticos, 3,95 vezes (HR; IC 95% 1,27 a 12,30) do risco dos não diabéticos. Indivíduos que praticavam atividade física vigorosa tiveram uma redução no risco de óbito em 51% (HR = 0,49; IC 95% 0,27 a 0,88). Para o aumento de 1 mmHg na pressão arterial sistólica houve uma redução de 2% (HR = 0,98; IC 95% 0,97 a 0,99) no risco de morte. Conclusão: Nesta amostra de longevos, não houve associação entre os genótipos da APOE e mortalidade. Entretanto, os fatores de risco cardiovasculares clássicos podem ser importantes para a mortalidade geral em pessoas muito idosas.

Abstract Background: Knowledge of environmental and genetic factors for healthy aging in elderly people is controversial. In addition to this evidence, few studies have been designed for this population. Objectives: To investigate the relationship between the most frequent apolipoprotein E (APOE) genotypes and mortality in very elderly individuals living in a community and to evaluate survival according to cardiovascular risk factors. Methods: A sample of 74 elderly individuals aged ≥ 80 years, from the Veranópolis Project cohort, was selected for APOE genotyping. At baseline, anthropometric variables, glucose and lipid levels, blood pressure, and lifestyle variables (smoking, alcohol consumption, and physical activity) were collected. The Bayer Activities of Daily Living Scale was applied to their caregivers. Total study follow-up was 21 years. Two-sided p < 0.05 was considered statistically significant. Results: There was no association between APOE genotypes and mortality. However, the risk of death in elderly smokers was 2.30 times higher (hazard ratio [HR], 95% CI 1.01 to 5.24); in individuals with diabetes, it was 3.95 times higher (HR, 95% CI 1.27 to 12.30) than in individuals without diabetes. Subjects who practiced vigorous physical activity had a 51% reduction in risk of death (HR = 0.49, 95% CI 0.27 to 0.88). For an increase of 1 mmHg in systolic blood pressure, there was a 2% reduction (HR = 0.98, 95% CI 0.97 to 0.99) in risk of death. Conclusion: In this sample population, APOE genotypes were not associated with mortality. However, classic cardiovascular risk factors may be important for overall mortality in the very elderly.

Farmacogenômica e Doença Cardiovascular: Onde Estamos e Para Onde Vamos / Pharmacogenomics and Cardiovascular Disease: Where are We and Where do We go from Here?

Resumo A farmacogenômica (FGx) investiga a interação entre genes e medicamentos. Através da análise de regiões específicas do DNA, informações sobre o perfil de metabolização do paciente para um determinado fármaco podem ser descritas, assim como o perfil esperado de resposta ao tratamento. Objetivamente, esse tipo de teste pode ter impacto no tratamento de pacientes que não estão respondendo adequadamente a um determinado medicamento, seja pela ausência dos efeitos esperados ou em virtude do aparecimento de efeitos adversos. Neste cenário, o objetivo desta revisão é o de informar o cardiologista clínico sobre esta importante área do conhecimento e atualizá-lo sobre o tema, procurando preencher as lacunas no que diz respeito à relação custo-benefício da aplicação da FGx nas doenças cardiovasculares, além de fornecer informações para a implementação da terapia guiada pela FGx na prática clínica.

Association of CYP2J2 polymorphism with susceptibility to psoriasis in Turkish population: a case-control study

Abstract Background: Cytochrome P450 2J2 is mostly expressed in extrahepatic tissues; it metabolizes arachidonic acid to epoxyeicosatrienoic acids, with various cardio protective and anti-inflammatory effects. CYP2J2 polymorphism has been identified as a risk factor for cardiovascular diseases, but its association with psoriasis remains unknown. Objective: To evaluate CYP2J2 polymorphism as a risk factor for psoriasis in the Turkish population. Methods: There were 94 patients with psoriasis and 100 age- and sex-matched healthy controls included in the study. Detailed demographic and clinical characteristics were recorded, and Psoriasis Area and Severity Index (PASI) scores were calculated for psoriasis patients. Venous blood samples were collected from all the participants and CYP2J2 50G>T (rs890293) polymorphism was analyzed using polymerase chain reaction (PCR). Results: Both T allele and TT + GT genotype frequencies were increased in psoriasis vulgaris patients compared to the control group (p = 0.024 and p = 0.029 respectively, OR = 2.82, 95% CI: 1.11-7.15) No association between CYP2J2 polymorphism and clinical features of psoriasis was identified. Study limitations: A limited number of patients were included in the study. Conclusion: CYP2J2 50G>T (rs890293) polymorphism was associated with an increased risk for PsV in the Turkish population.

High levels of chemerin associated with variants in the NOS3 and APOB genes in rural populations of Ouro Preto, Minas Gerais, Brazil

Chemerin is an adipokine that has been associated with components of metabolic syndrome. It has been described to affect adipocyte metabolism and inflammatory responses in adipose tissue, as well as the systemic metabolism of lipids and glucose. Few epidemiological studies have evaluated classical and genetics cardiovascular risk factors (CVRFs) in the mixed adult rural population in Brazil. Therefore, the present study explored possible associations between CVRFs and chemerin. This cross-sectional study included 508 adults from the rural localities of Lavras Novas, Chapada, and Santo Antônio do Salto in Ouro Preto, Minas Gerais, Southeast Brazil. Demographic, behavioral, clinical, biochemical, anthropometric variables, and 12 single nucleotide polymorphisms (SNPs) linked with metabolic syndrome phenotypes were evaluated for associations with chemerin level. There was a significant association of high triglyceride levels [odds ratio (OR)=1.91, 95%CI: 1.23−2.98], insulin resistance (OR=1.82, 95%CI: 1.03−3.22), age (OR=1.64, 95%CI: 1.08−2.49), and sex (OR=1.99, 95%CI: 1.35−2.95) with high levels of chemerin. High chemerin levels were significantly associated with the genetic polymorphisms rs693 in the APOB gene (OR=1.50, 95%CI: 1.03−2.19) and rs1799983 in the NOS3 gene (OR=1.46, 95%CI: 1.01−2.12) for the AA and GT+TT genotypes, respectively. In the concomitant presence of genotypes AA of rs693 and GT+TT of rs1799983, the chance of presenting high levels of chemerin showed a 2.21-fold increase (95%CI: 1.25−3.88) compared to the reference genotype. The development of classical CVRFs in this population may be influenced by chemerin and by two risk genotypes characteristic of variants in well-studied genes for hypertension and dyslipidemia.

Familial aggregation and heritability of markers of metabolic risk, physical activity, and physical fitness in nuclear families from Muzambinho (Minas Gerais, Brazil)

ABSTRACT Objective This study investigated the familial aggregation and heritability of markers of metabolic risk, physical activity, and physical fitness in nuclear families from Muzambinho (Minas Gerais, Brazil). Subjects and methods The study included members of 139 families, comprising 97 fathers (aged 40 ± 7 years), 129 mothers (35 ± 6 years), 136 sons (12 ± 4 years), and 121 daughters (12 ± 5 years). Evaluated markers included (A) body mass index, waist circumference, glycemia, and cholesterolemia, as metabolic risk markers; (B) total weekly volume of physical activity, as a physical activity marker; and (C) relative muscle strength, as a physical fitness marker. Correlations between family members and heritability (h2) were estimated using the software S.A.G.E. Results Significant familial correlations were obtained between parents-offspring for glycemia and cholesterolemia (both ρ = 0.21, p < 0.05) and relative muscle strength (ρ = 0.23, p < 0.05), and between siblings for waist circumference, glycemia, total weekly volume of physical activity, and relative muscle strength (ρ variation 0.25 to 0.36, p < 0.05). Heritability values were significant for almost all variables (h2 variations: 20% to 57% for metabolic risk markers, 22% for the total weekly volume of physical activity, and 50% for relative muscle strength), except for waist circumference (h2 = 15%, p = 0.059). Conclusion The presence of significant correlations between family members and/or significant heritability strengthens the possible genetic and/or common familial environment influence on metabolic risk markers, total weekly volume of physical activity, and relative muscle strength.

Ataxina-2, nuevo blanco en enfermedades genéticas complejas / Ataxin-2, a new target in complex genetic diseases

Resumen El gen de la ataxina-2 es un blanco en la patogénesis de enfermedades complejas, entre ellas los factores de riesgo cardiovascular y enfermedades neurodegenerativas. El gen ATXN2 tiene un VNTR en el exón 1, cuya expansión por encima de las 30 repeticiones provoca al desarrollo de ataxia espinocerebelosa tipo 2; las repeticiones en rango menor se asocian con diabetes tipo 2 o esclerosis lateral amiotrófica. También este locus está ligado con fenotipos metabólicos e inflamatorios. En conclusión, el gen puede ser utilizado como marcador clínico de fenotipos metabólicos y neurológicos, lo cual está relacionado con su efecto pleiotrópico.

Abstract The ataxin 2 gene is a target in the pathogenesis of complex diseases, including cardiovascular risk factors and neurodegenerative diseases. ATXN2 gen has VNTR in exon 1, whose expansion exceeding 30 repetitions leads to the development of spinocerebellar ataxia type 2; lower-range repetitions are associated with type 2 diabetes or amyotrophic lateral sclerosis. This locus is also linked with metabolic and inflammatory phenotypes. In conclusion, this gene can be used as a clinical marker of metabolic and neurological phenotypes, which is related to its pleiotropic effect.

Role of miRNAs on the Pathophysiology of Cardiovascular Diseases / Papel dos miRNAs na Fisiopatologia das Doenças Cardiovasculares

Abstract MiRNA (or microRNA) is a subclass of non-coding RNAs that is responsible for post-transcriptional gene regulation. It has approximately 22 nucleotides and regulates gene expression in plants and animals at the post-transcriptional level, by the cleavage of a target mRNA or by suppression of its translation. Although many of the processes and mechanisms have not yet been fully elucidated, there is a strong association between miRNA expression and several diseases. It is known that miRNAs are expressed in the cardiovascular system, but their role in cardiovascular diseases (CVDs) has not been clearly established. In this non-systematic review of the literature, we first present the definition of miRNAs and their action at the cellular level. Afterward, we discuss the role of miRNAs as circulating biomarkers of CVDs, and then their role in cardiac remodeling and atherosclerosis. Despite the complexity and challenges, it is crucial to identify deregulated miRNAs in CVDs, as it allows a better understanding of underlying cellular and molecular mechanisms and helps in the development of more accurate diagnostic and prognostic circulating biomarkers, and new therapeutic strategies for different stages of CVDs.

Resumo O miRNA (ou microRNA) constitui uma subclasse de RNAs não codificantes responsáveis pela regulação gênica pós-transcricional. Ele possui aproximadamente 22 nucleotídeos e regula a expressão gênica em plantas e animais ao nível pós-transcricional, pela clivagem de um mRNA alvo ou da repressão de sua tradução. Embora muitos processos e mecanismos ainda não estejam completamente elucidados, existe uma forte associação entre a expressão de miRNAs e diversas doenças que acometem o organismo. Os miRNAs são expressos no sistema cardiovascular, contudo o seu papel no desenvolvimento das doenças cardiovasculares (DCVs) ainda não está totalmente elucidado. Diante disso, realizou-se uma revisão não sistemática da literatura a fim de se discutir a relação entre os miRNAs e as DCVs. Nesta revisão, primeiramente é discutido o que são os miRNAs e a sua ação a nível celular. Após, é discutido o papel dos miRNAs como biomarcadores circulantes de DCVs e então o seu papel no remodelamento cardíaco e na aterosclerose. Apesar da complexidade e dos desafios, a identificação dos miRNAs desregulados nas DCVs é crucial, uma vez que possibilita uma melhor compressão dos mecanismos celulares e moleculares envolvidos, assim como auxilia o desenvolvimento de marcadores circulantes de diagnóstico e prognóstico mais acurados e de novas estratégias terapêuticas para os diferentes estágios da DCV.

Polymorphism related to cardiovascular risk in hemodialysis subjects: a systematic review / Polimorfismos associados ao risco cardiovascular em indivíduos em hemodiálise: uma revisão sistemática

ABSTRACT Cardiovascular disease (CVD) is one of the leading causes of mortality in hemodialysis (HD) subjects. In addition to the traditional risk factors that are common in these individuals, genetic factors are also involved, with emphasis on single nucleotide polymorphs (SNPs). In this context, the present study aims to systematically review the studies that investigated the polymorphisms associated with cardiovascular risk in this population. In general, the SNPs present in HD individuals are those of genes related to inflammation, oxidative stress and vascular calcification, also able of interfering in the cardiovascular risk of this population. In addition, polymorphisms in genes related to recognized risk factors for CVD, such as dyslipidemia, arterial hypertension and left ventricular hypertrophy, also influence cardiovascular morbidity and mortality.

RESUMO A doença cardiovascular (DCV) é uma das principais causas de mortalidade de indivíduos em hemodiálise (HD). Além dos fatores de risco tradicionais, que são frequentes nesses indivíduos, também estão envolvidos fatores genéticos, com destaque para os polimorfismos de nucleotídeo único (do inglês, single nucleotide polymorphism, SNP). O presente trabalho tem como objetivo revisar sistematicamente os estudos que investigaram os polimorfismos associados ao risco cardiovascular nessa população. De modo geral, os SNPs presentes em indivíduos em HD são aqueles de genes relacionados à inflamação, estresse oxidativo e calcificação vascular, também capazes de interferir no risco cardiovascular dos pacientes. Polimorfismos em genes relacionados a fatores de risco reconhecidos para DCV, como dislipidemia, hipertensão arterial e hipertrofia ventricular esquerda, também influenciam a morbidade e mortalidade cardiovascular.

III SBC Guidelines on the Analysis and Issuance of Electrocardiographic Reports - Executive Summary / III Diretrizes SBC para Análise e Emissão de Laudos Eletrocardiográficos - Resumo Executivo

Abstract The third version of the guidelines covers recently described topics, such as ion channel diseases, acute ischemic changes, the electrocardiogram in athletes, and analysis of ventricular repolarization. It sought to revise the criteria for overloads, conduction disorders, and analysis of data for internet transmission.

Resumo A terceira versão das diretrizes aborda tópicos recentemente descritos, como as doenças dos canais iônicos, alterações isquêmicas agudas, o eletrocardiograma dos atletas e análise da repolarização ventricular. Ela buscou rever critérios de sobrecargas, distúrbios de condução e análise de dados transmitidos via internet.

Family history of cardiovascular disease and non-HDL cholesterol in prepubescent non-obese children / Importância clínica da história familiar de doença cardiovascular e da dosagem do colesterol não HDL em crianças eutróficas

Summary Objective: To describe the values of non-HDL cholesterol (NHDL-c) and the frequency of a family history of early cardiovascular disease (family HCVD) in healthy prepubescent children. Analyze the association between NHDL-c and family HCVD, and possible associations with other risk factors for cardiovascular disease (CVD). Method: Cross-sectional study including 269 prepubescent (aged 6-10 years) schoolchildren with a normal body mass index (+1SD<BMI>-2SD). Data collected: Family HCVD; weight and height, waist circumference and systemic blood pressure; lipid profile (total cholesterol TC, HDL-c, triglycerides and LDL-c), NHDL-c calculation (CT-HDL-c, cut-off = 145 mg/dL) and insulin resistance (HOMA-IR). Results: High levels were found for NHDL-c in 10 (3.7%) of these schoolchildren, and family early HCVD was found in 46 (17.1%) of them. There was a weak association between family HCVD and NHDL-c (Cramer’s-V-test = 0.120; p=0.050). Among the children with NHDL-c≥145 mg/dL, 4 (40%) have family HCVD. The presence of family HCVD was not associated with the variables being studied. The variables independently associated with NHDL-c ≥ 145 mg/dL were: HOMA-IR (OR=1.7; 95CI 1.1-2.6) and diastolic blood pressure (OR=1.1; 95CI 1.02-1.2). Conclusion: NHDL-c values were associated with blood pressure and insulin resistance. Family HCVD was not associated with other classic risk factors for CVD, even though the frequency found was five times higher than that of high NHDL-c.

Resumo Objetivos: descrever os valores do colesterol não HDL (NHDL-c) e a frequência de história cardiovascular familiar precoce (HDCV familiar) em crianças eutróficas e pré-púberes. Analisar a associação entre o NHDL-c e o HDCV familiar e possíveis associações com outros fatores de risco para doenças cardiovasculares (DCV). Método: estudo transversal com 269 escolares (6-10 anos) pré-púberes e com índice de massa corporal normal (+1DP<IMC>-2DP). Dados coletados: HDCV familiar; peso e estatura, circunferência abdominal e pressão arterial sistêmica; perfil lipídico (colesterol total – CT, HDL-c, triglicérides e LDL-c), cálculo do NHDL-c (CT-HDL-c, ponto de corte 145 mg/dL) e resistência à insulina (HOMA-IR). Resultados: observaram-se valores elevados de NHDL-c em 10 (3,7%) e presença de HDCV familiar precoce em 46 (17,1%) crianças. Houve fraca associação entre HDCV familiar e NHDL-c (Cramer’s-V-test = 0,120; p=0,050). Entre as crianças com NHDL-c ≥145 mg/dL, quatro (40%) tinham HDCV familiar. A presença de HDCV familiar não se associou com as variáveis estudadas. As variáveis que se associaram de forma independente com o NHDL-c ≥145 mg/dL foram HOMA-IR (OR=1,7; IC95% 1,1-2,6) e pressão arterial diastólica (OR=1,1; IC95% 1,02-1,2). Conclusão: os valores de NHDL-c se associaram com pressão arterial e resistência insulínica. HDCV familiar não se associou com outros fatores de risco clássicos para DCV, embora a frequência encontrada tenha sido quase cinco vezes superior à de NHDL-c elevado.

Lifetime Prevalence of Transient Loss of Consciousness in an Urban Russian Population / Prevalência de Perda de Consciência Temporária em População Russa Urbana

Abstract Background: Most international studies on epidemiology of transient loss of consciousness (TLC) were performed many years ago. There are no data about the lifetime prevalence of TLC in Russia. Objective: To identify the lifetime prevalence and presumed mechanisms of TLC in an urban Russian population. Methods: 1796 individuals (540 males [30.1%] and 1256 females [69.9%]) aged 20 to 69 years (mean age 45.8 ± 11.9 years) were randomly selected and interviewed within the framework of multicentre randomised observational trial. Results: The overall prevalence of TLC in the studied population was 23.3% (418/1796), with the highest proportion (28%) seen in 40-49 year age group. TLC was significantly more common in women than in men (27.5% vs 13.5%). The mean age of patients at the time of the first event was 16 (11; 23) years, with 333 (85%) individuals experiencing the first episode of TLC under 30 years. The average time after the first episode of TLC was 27 (12; 47) years. The following mechanisms of TLC were determined using the questionnaire: neurally-mediated syncope (56.5%), arrhythmogenic onset of syncope (6.0%), nonsyncopal origin of TLC (1.4%), single episode during lifetime (2.1%). Reasons for TLC remained unidentified in 34% cases. 27 persons (6.5%) reported a family history of sudden death, mainly patients with presumably arrhythmogenic origin (24%). Conclusion: Our findings suggest that the overall prevalence of TLC in individuals aged 20-69 years is high. The most common cause of TLC is neurally-mediated syncope. These data about the epidemiology can help to develop cost-effective management approaches to TLC.

Resumo Fundamento: A maioria dos estudos internacionais sobre epidemiologia da perda de consciência temporária (PCT) foi realizada há muitos anos. Não há dados sobre sua prevalência ao longo da vida na Rússia. Objetivo: Identificar a prevalência ao longo da vida e os supostos mecanismos da PCT em uma população russa urbana. Métodos: 1.796 indivíduos (540 homens 30,1% e 1.256 mulheres 69,9%) com idade entre 20 e 69 anos (idade média, 45,8 ± 11,9 anos) foram selecionados aleatoriamente e entrevistados no contexto de um estudo multicêntrico randomizado observacional. Resultados: A prevalência global de PCT na população estudada foi 23,3% (418/1.796), sendo a mais alta proporção (28%) observada na faixa etária de 40-49 anos. PCT foi significativamente mais comum nas mulheres (27,5% vs 13,5%). A idade média dos pacientes por ocasião do primeiro evento foi 16 (11; 23) anos, com 333 (85%) indivíduos experienciando o primeiro episódio de PCT antes dos 30 anos. O tempo médio após o primeiro episódio de PCT foi 27 (12; 47) anos. Os seguintes mecanismos de PCT foram determinados usando-se um questionário: síncope neuromediada (56,5%), síncope de origem arritmogênica (6,0%), PCT de origem não sincopal (1,4%), episódio único durante a vida (2,1%). A causa de PCT não foi identificada em 34% dos casos, sendo que 27 pacientes (6,5%) relataram história familiar de morte súbita, principalmente aqueles com PCT de suposta origem arritmogênica (24%). Conclusão: Nossos achados sugerem uma alta prevalência global de PCT em indivíduos com idade entre 20 e 69 anos. A causa mais comum de PCT é a síncope neuromediada. Esse dado sobre a epidemiologia pode contribuir para o desenvolvimento de abordagem custo-efetiva para PCT.