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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.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.

Resumo Fundamento A ablação da taquicardia atrial (TA) com local de ativação mais precoce próxima ao feixe de His é um desafio, devido ao risco de bloqueio de AV completo por sua proximidade ao sistema de His-Purkinje (SHP). Uma alternativa para minimizar esse risco é posicionar o cateter na cúspide não coronária (CNC), que é anatomicamente contígua à região para-Hissiana. Objetivos O objetivo deste estudo foi fazer uma revisão de literatura e avaliar as características eletrofisiológicas, a segurança e o índice de sucesso de aplicação de radiofrequência (RF) por cateter na CNC para o tratamento de TA para-Hissiana em uma série de casos. Métodos Avaliamos retrospectivamente dez pacientes (Idade: 36±10 anos) que foram encaminhados para ablação de taquicardia paroxística supraventricular (TPSV) e haviam sido diagnosticados com TA focal para-Hissiana confirmada por manobras eletrofisiológicas clássicas. Para a análise estatística, um P valor d

Breve Historia Eduardo Argentino Sosa nasceu em Corrientes, Argentina, em 25 de janeiro de 1942. Iniciou o curso de medicina na Faculdade de Ciencias Medicas da Universidade Nacional do Nordeste, na sua cidade natal; no entanto, devido a situacao politica que afetava o funcionamento universitario na Argentina de entao, transferiu-se para a Faculdade de Ciencias Medicas de Cordoba e, posteriormente, para a Faculdade de Ciencias Medicas da Universidade Nacional do Litoral, na cidade de Rosario, onde concluiu o curso em [...]

Introducao Em dezembro de 2019, foram relatados os primeiros casos da doenca causada pelo novo coronavirus (COVID-19), originarios de Wuhan, China. Desde a declaracao de pandemia em marco de 2020 por Organizacao Mundial da Saude (OMS), com disseminacao intercontinental, vivenciamos intensa busca por um tratamento seguro e eficaz. Estudos in vitro demonstraram algum efeito da cloroquina contra o novo coronavirus, intermediada pela glicosilacao dos receptores celulares de SARS-CoV e pelo aumento do pH endossomico, bloqueando a invasao celular pelo virus. [...]

Cardiovascular manifestations of COVID-19 include cardiac rhythm disturbances, whose mechanisms, incidence, and most common types are not well established in this population. Intense inflammatory response and metabolic activity contribute to recurrence of pre-existing arrhythmias, and other arrhythmias can occur due to myocardial injury, acute coronary insufficiency, and electrolyte disturbances. Brady- and tachyarrhythmias, as well as conduction disorders have been described. QT interval prolongation and fatal ventricular arrhythmias ( Torsades de Pointes ) may result from the pathological process or adverse effect of drugs (antiarrhythmics, chloroquine / hydroxychloroquine, azithromycin and antivirals). Patients with congenital heart disease and hemodynamic repercussions, patients with signs of heart failure, pulmonary hypertension, cyanosis, hypoxemia, and those who underwent heart transplantation and immunosuppression are at greater risk. In patients with implantable cardioverter-defibrillators (ICDs), the risk depends on the presence of structural heart disease. In the course of COVID-19, in-person assessment of these patients should be limited to high-risk situations, including syncope, worsening of heart failure and shock delivery by ICDs. Likewise, cardiac implantable electronic device implantation or replacement surgery should be limited to emergency and urgent cases, including symptomatic high-degree atrioventricular block, ICD for secondary prevention and pulse generator replacement due to battery drain.

The atrioventricular (AV) reentrant tachycardia (AVRT) is the most common cause of supraventricular tachycardia (SVT) in the young pediatric population. Some newborns might present with congestive heart failure and require interventional treatment. Catheter ablation in small infants (

Background Type 1 diabetes mellitus can cause autonomic changes, which can be assessed by heart rate variability. Among the heart rate variability assessment methods, the symbolic analysis and Shannon entropy, based on the Chaotic dynamics, have gained prominence. Objective To compare heart rate variability indexes, obtained through symbolic analysis and Shannon entropy, in young adults with type 1 diabetes mellitus and healthy young individuals, associated with the analysis of linear indexes; and to verify if there are associations between the indexes obtained by the symbolic analysis and by Shannon entropy and linear indexes in diabetic individuals. Methods Heart rate variability data from 39 young adults with type 1 diabetes mellitus and 43 healthy young individuals were analyzed, using a cardio-frequency meter. Linear indexes (standard deviation of all normal RR intervals recorded in a time interval expressed in milliseconds; square root of the mean of the squared differences between adjacent normal RR intervals in a time interval expressed in milliseconds; low and high frequency components in millisecond squared; and normalized units and ratio between low and high frequency components) and nonlinear ones (Shannon entropy and symbolic analysis - standard without variation; with one or two variations; and with two different variations) of the heart rate variability were calculated. The statistical significance was set at 5%, and the confidence interval was 95%. Results Significantly lower values were observed in the DM1 group compared to healthy young adults for the standard deviation indexes of all normal RR intervals recorded in a time interval [37.30 (29.90) vs. 64.50 (36.20); p = 0.0001], square root of the mean of the squared differences between adjacent normal RR intervals in a time interval [32.73 (17.43) vs. 55.59 (21.60); p = 0.0001], low frequency component [402.00 (531.00) vs. 1,203.00 (1,148.00); p = 0.0001], high frequency component [386.00 (583.00) vs. 963.00 (866.00); p = 0.0001] and the pattern with two different variations [15,33 (9,22) vs. 20.24 (12.73); p = 0.0114], with the effect of this difference being considered large (standard deviation of all normal RR intervals recorded in a time interval, square root of the mean of the squared differences between adjacent normal RR intervals in a time interval and low frequency component), medium (high frequency component) and small (standard with two different variations). The agreement of the associations between the linear and non-linear indexes was considered elevated for the high frequency component index - normalized units (r = -0.776), with the standard index without variation, and moderate for the indexes square root of the mean of the squared differences between adjacent normal RR intervals in a time interval (r = 0.550), standard deviation of all normal RR intervals recorded in a time interval (r = 0.522), high frequency component - normalized units (r = 0.638) with the index standard with two similar variations, as well as for the indexes square root of the mean of the squared differences between adjacent normal RR intervals in a time interval (r = 0.627) and high frequency component - normalized units (r = 0.601) with the index standard with two different variations. Conclusion Type 1 diabetes mellitus influenced linear indexes and symbolic analysis, but not yet in the complexity of heart rate variability. Additionally, heart rate variability indexes correlated with the symbolic dynamics.

Nos ultimos anos, a fibrilacao atrial (FA) e a insuficiencia cardiaca (IC) tem sido as duas principais sindromes epidemicas em cardiologia, e frequentemente coexistem. A IC aumenta valores medios da pressao atrial direita e esquerda, promovendo sua dilatacao progressiva. Esse remodelamento eletroanatomico predispoe a fibrose atrial e a heterogeneidade eletrica, e aumenta o desenvolvimento de ritmo ectopico, induzindo FA. Um novo episodio de FA, por sua vez, induz a perda de contracao atrial, provoca um aumento na frequencia cardiaca e [...]

Introducao A fibrilacao atrial (FA) e a arritmia cardiaca sustentada mais comum na pratica clinica. Sua prevalencia aumenta com a idade e frequentemente esta associada a doencas estruturais cardiacas, levando a danos hemodinâmicos e complicacoes tromboembolicas com grandes implicacoes economicas e na morbimortalidade da populacao., As tecnicas de ablacao de FA, quando realizadas por operadores experientes, tem se mostrado seguras e com resultados bastante satisfatorios, porem em alguns pacientes e necessaria a abordagem de focos extra-venosos, como apendice atrial esquerdo, [...]

"Torsades de pointes" (TdP) ventricular tachycardias carry a high risk of sudden death, even when they occur in individuals with a structurally normal heart, in the absence of myocardial ischemia or prolonged QT interval. Leenhardt et al1 described a new syndrome with these characteristics in 1994 that showed a difference in which the TdP were triggered by ventricular extrasystoles (VE) with ultra-short coupling interval (< 300 ms). Although this condition is easily diagnosed by the described characteristics, there is a lack of data on the clinical management of patients during the phase of electrical storm and during long-term clinical outcome. Over the past 20 years, three patients were identified in our institution with this clinical condition, as well as a family member with VE and short coupling interval, asymptomatic and without documented polymorphic ventricular tachycardia (VT). The aim of this case report is to describe the clinical management used in these patients and review the literature on the implication of the finding of VE with short coupling interval in asymptomatic family members.

The Chagas Heart Disease, described for the first time in 1909 by Carlos Chagas, is caused by Trypanosoma cruzi, a flagellated protozoa transmitted to humans, mostly by the feces of Triatoma infestans in endemic areas. Estimates are that fifteen million people are infected in Latin America, leading to 45,000 deaths per year, 90% owing to heart disease. The cardiac involvement is the most prevalent and severe manifestation of Chagas Heart Disease. After the infection, most individuals remain without manifestation of the disease along their lives, but at least 30% develop heart rhythm disorders, severe symptoms of heart failure and thromboembolic events, typically after 10-30 years after infection. Chronic myocarditis predisposes to cardiac dilation and to the formation of ventricular aneurysms. Thrombi are more prevalent in apical ventricular aneurysm, which is typical of the disease, and the cause for thromboembolic events in the systemic and pulmonary circulation. Segmental myocardial fibrosis is the anatomical substrate for ventricular arrhythmias and atrio-ventricular and intraventricular conduction abnormalities. Sudden death occurs in 55-65% of the patients, at times in the absence of prior cardiac symptoms. Death as a result of heart failure happens in 25-30%, and cerebral or pulmonary embolism, in 10-15%1-3. Ventricular extrasystoles are rather common in patients with Chagas Heart Disease, and its prevalence and complexity are associated with the extent of myocardial injury, particularly with left ventricular dysfunction and dilation4. Non-sustained ventricular tachycardia (NSVT) has been recognized as an independent risk factor for death and included in score for risk stratification5. Sustained ventricular tachycardia (SVT) is considered the main cause of sudden death, and may happen in different stages of the disease and even in patients without important ventricular dysfunction6. Amiodarona is the most commonly used antiarrhythmic drug in Brazil to treat ventricular arrhythmias in patients with Chagas Heart Disease. Cohort studies involving patients with sustained Chagas Heart Disease and VT revealed 5-11.9% of annual mortality, with sudden death representing 61-78% of the cases, mostly with important ventricular systolic dysfunction7-10. On account of this, the implantable cardioverter defibrillator (ICD) has been recommended to patients with sustained VT and ventricular dysfunction11-14. However, patients with Chagas Heart Disease seem to receive more ICD shocks compared to patients with coronary heart disease. A relevant finding was the annual mortality of 16.6% in a cohort of 90 patients with Chagas Heart Disease subject to ICD implantation due to sustained VT. Although the patients presented low rate of sudden death, they had a significant rate of total mortality. Patients with more than four shocks over a period of 30 days presented higher mortality compared to patients with no shock or a smaller number11. Since these patients mostly died from heart failure, one can speculate that excessive shocks applied by ICD may depress the ventricular function and increase non-sudden mortality. This data corroborate the indication of catheter ablation as the logical strategy to reduce the recurrence of sustained VT and prevent ICD shocks15.

Background: Cardiac resynchronization therapy (CRT) is the recommended treatment by leading global guidelines. However, 30%-40% of selected patients are non-responders. Objective: To develop an echocardiographic model to predict cardiac death or transplantation (Tx) 1 year after CRT. Method: Observational, prospective study, with the inclusion of 116 patients, aged 64.89 ± 11.18 years, 69.8% male, 68,1% in NYHA FC III and 31,9% in FC IV, 71.55% with left bundle-branch block, and median ejection fraction (EF) of 29%. Evaluations were made in the pre‑implantation period and 6-12 months after that, and correlated with cardiac mortality/Tx at the end of follow-up. Cox and logistic regression analyses were performed with ROC and Kaplan-Meier curves. The model was internally validated by bootstrapping. Results: There were 29 (25%) deaths/Tx during follow-up of 34.09 ± 17.9 months. Cardiac mortality/Tx was 16.3%. In the multivariate Cox model, EF < 30%, grade III/IV diastolic dysfunction and grade III mitral regurgitation at 6‑12 months were independently related to increased cardiac mortality or Tx, with hazard ratios of 3.1, 4.63 and 7.11, respectively. The area under the ROC curve was 0.78. Conclusion: EF lower than 30%, severe diastolic dysfunction and severe mitral regurgitation indicate poor prognosis 1 year after CRT. The combination of two of those variables indicate the need for other treatment options. Resumo Fundamento: A terapia de ressincronização cardíaca (TRC) é um tratamento recomendado pelas principais diretrizes mundiais. Entretanto, 30%-40% dos pacientes selecionados não respondem ao tratamento. Objetivo: Elaborar um modelo ecocardiográfico preditor de risco de óbito cardíaco ou transplante (Tx) após 1 ano da TRC. Método: Estudo observacional, prospectivo, com inclusão de 116 pacientes, sendo 69,8% do sexo masculino, com idade de 64,89 ± 11,18 anos, CF III (68,1%) e IV ambulatorial (31,9%), bloqueio de ramo esquerdo em 71,55%, e mediana da fração de ejeção (FE) de 29%. Avaliações foram feitas no período pré-implante e 6-12 meses após, e correlacionadas com mortalidade cardíaca/Tx no final do seguimento. Foram realizadas análises de regressão de Cox e logística, com a curva ROC e de sobrevida de Kaplan-Meier. O modelo foi validado internamente pelo “bootstrapping”. Resultados: Ocorreram 29 (25%) óbitos/Tx durante o seguimento de 34,09 ± 17,9 meses. A mortalidade cardíaca/Tx foi de 16,3 %. No modelo multivariado de Cox, as variáveis FE < 30%, disfunção diastólica grau III/IV e regurgitação mitral grau III, aferidas com 6-12 meses, relacionaram-se independentemente a aumento de mortalidade cardíaca ou Tx, com razões de risco de 3,1, 4,63 e 7,11, respectivamente. A área sob a curva ROC foi de 0,78. Conclusão: FE menor que 30%, disfunção diastólica grave e regurgitação mitral severa indicam pior prognóstico após 1 ano da TRC, devendo ser consideradas outras opções terapêuticas na presença da combinação de duas dessas variáveis.

Hypertension is the cause of thousands of deaths annually1, and half of the patients treated present controlled blood pressure (BP)2. Resistant hypertension (RH)is defined when the BP remains above the recommended targets with the use of three antihypertensive drugs with synergistic actions at maximum doses recommended and tolerated, preferably one being a diuretic, or when in use of four or more anti-hypertensive drugs, even with controlled BP3. It is estimated that 12%-15% of persons with hypertension are considered resistant, with high risk of cardiovascular morbidity and mortality4. The pathogenesis of hypertension is multifactorial, but the sympathetic activity plays an important role, especially in patients with resistant hypertension2. Efferent renal sympathetic activity stimulates renin release, increases sodium reabsorption and reduces renal blood flow and may be a mechanism for the development and maintenance of hypertension2. Genetic, behavioral and environmental factors influence increased sympathetic activity in persons with hypertension5. New therapies aiming to reduce sympathetic activity have been developed. Renal Sympathetic Denervation (RSD) by radiofrequency catheter ablation of renal arteries has been shown to control BP in resistant hypertension6,7 and in associated clinical conditions such as sleep destructive apnea8 and insulin resistance9. The main RSD clinical studies used a specific catheter not yet available in Brazil, but the radiofrequency ablation of arrhythmias is a procedure that has been performed by electrophysiologists through appropriate catheters for years in our country. Experimental studies of RSD with catheters used for ablation of arrhythmias indicated the possibility of using these to replace those used in international studies, considering the unavailability of those in our reality. Based on this, for the procedure to be reported, the model used for ablation in children (4 mm tip and 5F), which was proven to be more appropriate, was chosen. The objective of the report is to show the result of the first RSD in our community, with the aid of technology used in cardiac arrhythmias.