Taquicardia ventricular polimórfica tipo torsadess de pointes secundaria a estimulación por marcapasos / Polymorphic ventricular taquicardia "torsades de pointes" associated to abnormal pacemaker stimulation

La taquicardia ventricular polimórfica se origina en los ventrículos, cuyos complejos QRS son de morfología, amplitud y dirección variable, con frecuencias que oscilan entre 200 y 250 lpm, pudiendo ser autolimitadas o degenerar en una fibrilación ventricular. La TdP es un tipo de taquicardia ventricular polimórfica caracterizada por complejos con un eje eléctrico que gira alrededor de la línea isoeléctrica y que está asociada a QT largo. Se presenta el caso de una paciente portadora de marcapaso que presenta episodios de taquicardia ventricular polimórfica, con una morfología típica de TdP, sin documentación de QT prolongado previo ni actual, generada por la estimulación ventricular sobre onda T, de forma accidental por desplazamiento del electrodo auricular a Ventrículo Derecho (VD).

Polymorphic ventricular tachycardia is a tachycardia originating in the ventricles, where the QRS complexes have variable morphology, amplitude, and direction, with frequencies ranging between 200 and 250 bpm; it may be self-limited or degenerate into ventricular fibrillation. Torsades de Pointes (TdP) is a type of polymorphic ventricular tachycardia characterized by complexes with an electrical axis that rotates around the isoelectric line and that is associated with long QT interval. We present the case of a patient with a pacemaker who presents episodes of polymorphic ventricular tachycardia, with a typical morphology of TdP, without documentation of previous or current prolonged QT, generated by ventricular stimulation on the T wave, accidentally due to displacement of the atrial electrode to the Right Ventricle (RV).

Arritmias cardíacas em pacientes com COVID-19 / Cardiac arrhythmias in patients with COVID-19

Resumo Fundamento: A doença pelo novo coronavírus (COVID-19) está associada a manifestações clínicas cardiovasculares, incluindo a ocorrência de arritmias cardíacas. Objetivos: Avaliar a incidência de arritmias cardíacas (taquiarritmia atrial, bradiarritmia e taquicardia ventricular sustentada) e de parada cardiorrespiratória (PCR) em uma coorte de pacientes internados com COVID-19 em hospital universitário terciário. Métodos: Estudo de coorte retrospectivo realizado por meio de revisão dos registros de prontuário médico. Para comparação entre os grupos, foi considerado como estatisticamente significativo valor de P < 0,05. Resultados: Foram incluídos 241 pacientes consecutivos com diagnóstico de COVID-19 (idade média, 57,8 ± 15,0 anos; 51,5% homens; 80,5% de raça branca) e 35,3% com necessidade de ventilação mecânica invasiva (VM). A mortalidade geral foi de 26,6%, sendo de 58,8% entre aqueles em VM. Arritmias cardíacas ocorreram em 8,7% dos pacientes, sendo a mais comum taquiarritmia atrial (76,2%). Pacientes com arritmias apresentaram maior mortalidade, 52,4% versus 24,1% (p=0,005). Em análise multivariada, apenas a presença de insuficiência cardíaca foi associada a maior risco de arritmias ( hazard ratio , 11,9; IC 95%: 3,6-39,5; p<0,001). Durante a internação, 3,3% dos pacientes foram atendidos em PCR, com predomínio de ritmos não chocáveis. Todos os atendidos em PCR evoluíram com óbito durante a internação. Conclusão: A incidência de arritmias cardíacas em pacientes internados com COVID-19 em hospital terciário brasileiro foi de 8,7%, sendo a mais comum taquiarritmias atrial. A presença de insuficiência cardíaca foi associada a maior risco de arritmias. Pacientes com COVID-19 atendidos em PCR apresentam elevada mortalidade.

Abstract Background: The coronavirus disease 2019 (COVID-19) is associated with cardiovascular clinical manifestations, including cardiac arrhythmias. Objective: To assess the incidence of cardiac arrhythmias (atrial tachyarrhythmia, bradyarrhythmia, and sustained ventricular tachycardia) and cardiac arrest (CA) in a cohort of patients hospitalized with COVID-19 in a tertiary university-affiliated hospital. Methods: Cohort study with retrospective analysis of electronic medical records. For comparison between groups, a value of p <0.05 was considered statistically significant Results: We included 241 consecutive patients diagnosed with COVID-19 (mean age, 57.8 ± 15.0 years; 51.5% men; 80.5% white), 35.3% of whom received invasive mechanical ventilation (MV). The overall mortality was 26.6%, being 58.8% among those on MV. Cardiac arrhythmias were identified in 8.7% of the patients, the most common being atrial tachyarrhythmia (76.2%). Patients with arrhythmias had higher mortality (52.4% versus 24.1%, p = 0.005). On multivariate analysis, only the presence of heart failure (HF) was associated with a higher risk of arrhythmias (hazard ratio, 11.9; 95% CI: 3.6-39.5; p <0.001). During hospitalization, 3.3% of the patients experienced CA, with a predominance of non-shockable rhythms. All patients experiencing CA died during hospitalization. Conclusions: The incidence of cardiac arrhythmias in patients admitted with COVID-19 to a Brazilian tertiary hospital was 8.7%, and atrial tachyarrhythmia was the most common. Presence of HF was associated with an increased risk of arrhythmias. Patients with COVID-19 experiencing CA have high mortality.

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.

Características clínicas y complicaciones del síndrome de Takotsubo en un centro de referencia de la seguridad social peruana / Clinical features and complications of Takotsubo syndrome in a peruvian social security referral center

RESUMEN Con el objetivo de describir las características clínicas y complicaciones del síndrome de Takotsubo, se realizó un estudio de serie de casos de pacientes que ingresaron con esta patología al Instituto Nacional Cardiovascular-INCOR en Lima-Perú, entre enero de 2013 a diciembre de 2018. Se incluyeron 26 pacientes, con una edad promedio de 69 años y predominio del sexo femenino (96,2%), además un desencadenante se identificó en 23 casos (88,5%). En el electrocardiograma, el 61,5% tuvo supradesnivel del segmento ST; y en la evolución el 92,3% mostró ondas T negativas y el 38,5% un intervalo QTc >500 ms. Las complicaciones intrahospitalarias fueron choque cardiogénico (11,5%), fibrilación auricular (7,7%) y taquicardia ventricular (7,7%). En esta serie, el síndrome de Takotsubo predominó en mujeres posmenopáusicas, generalmente desencadenado por un factor estresante, con una baja tasa de complicaciones y ausencia de mortalidad intrahospitalaria.

ABSTRACT In order to describe the clinical features and complications of Takotsubo syndrome, a case series study was conducted with patients admitted with this pathology to the National Cardiovascular Institute-INCOR in Lima-Peru between January 2013 and December 2018. Twenty-six patients (26) were included, with an average age of 69 years and female predominance (96.2%); additionally, a trigger was identified in 23 cases (88.5%). In the electrocardiogram, 61.5% had ST segment elevation; and, in the evolution, 92.3% showed negative T waves and 38.5% a QTc interval >500 ms. In-hospital complications were cardiogenic shock (11.5%), atrial fibrillation (7.7%) and ventricular tachycardia (7.7%). In this series, Takotsubo syndrome predominated in postmenopausal women, usually triggered by a stressor, with a low complication rate and no in-hospital mortality.

Cohort of Patients Referred for Brugada Syndrome Investigation in an Electrophysiology Service - 19-Year Registry / Coorte de Pacientes Encaminhados para Investigação de Síndrome de Brugada em um Serviço Terciário de Eletrofisiologia - Registro de 19 Anos

Abstract Background: Brugada syndrome (SBr) is an arrhythmic condition characterized by ST-T segment abnormalities in the right precordial leads associated with a high risk of ventricular arrhythmias and sudden death. Local data regarding the clinical characteristics of patients with a typical electrocardiographic (ECG) pattern undergoing electrophysiological study are scarce. Objective: To evaluate patients with an ECG pattern suggestive of SBr referred for electrophysiological evaluation in a specialized center. Methods: Cohort study of patients referred for electrophysiological study because of an ECG pattern compatible with SBr between January 1998 and March 2017. Results: Of the 5506 procedures, 35 (0.64%) were for SBr investigation, 25 of which (71.42%) were performed in men. The mean age was 43.89 ± 13.1 years. The ECG patterns were as follows: type I, 22 (62.85%); type II, 12 (34.30%); and type III, 1 (2.85%). Twenty-three patients (65.7%) were asymptomatic, 6 (17.14%) had palpitations, 5 (14.3%) had syncope, and 3 (8.6%) had a family history of sudden death. Electrophysiological study induced ventricular tachyarrhythmias in 16 cases (45.7%), the mean ventricular refractory period being 228 ± 36 ms. Ajmaline / procainamide was used in 11 cases (31.4%), changing the ECG pattern to type I in 7 (63.6%). Sixteen cases (45.7%) received an implantable cardioverter defibrillator (ICD). In a mean 5-year follow-up, 1 of the 16 patients (6.25%) with ICD had appropriate therapy for ventricular fibrillation. There was no death. Other arrhythmias occurred in 4 (11.4%) cases. Conclusions: Most patients are men, and a type I ECG pattern is the main indication for electrophysiological study. Class IA drugs have a high ECG conversion rate. The ICD event rate was 6%. (Arq Bras Cardiol. 2018; [online].ahead print, PP.0-0)

Resumo Fundamento: Síndrome de Brugada (SBr) é uma condição arrítmica definida por anormalidades do segmento ST-T em derivações V1-V3 associada a risco elevado de arritmias ventriculares e morte súbita. Dados locais quanto às características clínicas dos pacientes com padrão eletrocardiográfico (ECG) típico avaliados por estudo eletrofisiológico (EEF) são escassos. Objetivo: Avaliar pacientes com padrão ECG sugestivo de SBr encaminhados para EEF em um centro especializado. Métodos: Estudo de coorte de casos encaminhados para EEF por padrão ECG compatível com SBr, entre janeiro de 1998 e março de 2017. Resultados: Dos 5506 procedimentos, 35 (0,64%) foram para investigação de SBr. Vinte e cinco (71,42%) eram homens. Idade média 43,89 ± 13,1 anos. Apresentação ECG foi tipo I em 22 casos (62,85%), tipo II em 12 (34,30%) e tipo III em 1 (2,85%). Vinte e três (65,7%) eram assintomáticos, 6 (17,14%) apresentavam palpitações, 5 (14,3%) síncope, 3 (8,6%) história familiar de morte súbita. Estudo eletrofisiológico induziu taquiarritmias ventriculares em 16 casos (45,7%), sendo o período refratário ventricular médio de 228 ± 36 ms. Utilizou-se ajmalina/procainamida em 11 casos (31,4%), sendo o padrão ECG transformado em tipo I em 7 (63,6%). Dezesseis casos (45,7%) receberam cardiodes fibrilador (CDI). Em seguimento médio de 5 anos, 1 dos 16 pacientes (6,25%) com CDI teve terapia apropriada para fibrilação ventricular. Nenhuma morte foi registrada. Outras arritmias ocorreram em 4 (11,4%) casos. Conclusões: Homens são maioria, sendo o padrão ECG tipo I a principal indicação de EEF. Droga classe IA possui alta taxa de conversão do padrão ECG. A taxa de eventos no CDI foi de 6%. (Arq Bras Cardiol. 2018; [online].ahead print, PP.0-0)

Association between Microvolt T-Wave Alternans and Malignant Ventricular Arrhythmias in Chagas Disease / Associação entre Microalternância de Onda T e Arritmias Ventriculares Malignas na Doença de Chagas

Abstract Background: Sudden cardiac death is the most frequent death mechanism in Chagas disease, responsible for 55% to 65% of the deaths of patients with chronic Chagas cardiomyopathy (CCC). The most often involved electrophysiological mechanisms are ventricular tachycardia and ventricular fibrillation. The implantable cardioverter defibrillator (ICD) has a beneficial role in preventing sudden death due to malignant ventricular arrhythmias, and, thus the correct identification of patients at risk is required. The association of microvolt T-wave alternans (MTWA) with the appearance of ventricular arrhythmias has been assessed in different heart diseases. The role of MTWA is mostly unknown in patients with CCC. Objectives: To evaluate the association between MTWA and the occurrence of malignant ventricular arrhythmias in patients with CCC. Method: This is a case-control study including patients with CCC and ICD, with history of malignant ventricular arrhythmias (case group), and patients with CCC and no history of those arrhythmias (control group). The MTWA test results were classified as negative and non-negative (positive and indeterminate). The significance level adopted was a = 0.05. Results: We recruited 96 patients, 45 cases (46.8%) and 51 controls (53.1%). The MTWA test was non-negative in 36/45 cases (80%) and 15/51 controls (29.4%) [OR = 9.60 (95%CI: 3.41 - 27.93)]. After adjustment for known confounding factors in a logistic regression model, the non-negative result continued to be associated with malignant ventricular arrhythmias [OR = 5.17 (95%CI: 1.05 - 25.51)]. Conclusion: Patients with CCC and history of malignant ventricular arrhythmias more often have a non-negative MTWA test as compared to patients with no history of arrhythmia.

Resumo Fundamento: A morte súbita cardíaca é o mecanismo de morte mais comum na doença de Chagas, responsável pelo óbito de 55% a 65% dos pacientes com cardiomiopatia chagásica crônica (CCC). Os mecanismos mais frequentemente envolvidos são as taquiarritmias ventriculares. O cardioversor-desfibrilador implantável (CDI) apresenta impacto na redução da mortalidade por arritmias ventriculares e faz-se necessária a correta identificação de pacientes sob risco. A associação de microalternância de onda T (MTWA) com o aparecimento de arritmias ventriculares foi avaliada em diferentes cardiopatias através de um teste. O papel da MTWA na identificação de pacientes sob risco na CCC permanece incerto. Objetivo: Avaliar a associação entre MTWA e a ocorrência de arritmias ventriculares malignas na CCC. Método: Trata-se de um estudo caso-controle, que incluiu pacientes com CCC em uso de CDI, com história prévia de arritmias ventriculares malignas (casos) ou sem história prévia (controles). Os resultados do teste foram classificados em negativo e não negativo (positivo e indeterminado). O nível de significância foi a = 0,05. Resultado: Foram recrutados 96 pacientes, 45 no grupo caso (46,8%) e 51 no grupo controle (53,1%). O teste de MTWA apresentou resultado não negativo em 36/45 pacientes no grupo caso (80%) e 15/51 no grupo controle (29,4%), OR = 9,60 (IC95%: 3,41 - 27,93). Após ajuste para fatores de confusão num modelo de regressão logística, o resultado não negativo continuou associado à presença de arritmias ventriculares malignas, com OR = 5,17 (IC95%: 1,05 - 25,51). Conclusão: Na CCC, pacientes com história de arritmia ventricular maligna apresentam maior frequência de teste de MTWA não negativo quando comparados a pacientes sem ocorrência prévia de arritmias.

Taquicardia ventricular como expresión de distrofia miotónica tipo 1 / Type I myotonic dystrophy presenting with ventricular tachycardia

Abstracts: A 48-year-old woman was brought to the emergency room with ventricular tachycardia that was eventually terminated by cardioversion. Clinical and neurologic evaluation, including electromyography were highly suggestive of type I Myotonic Dystrophy and genetical studies confirmed the diagnosis. A discussion about the diagnostic procedures and management of the disease, especially the associated ventricular tachycardia, is included.

Distúrbios de condução cardíaca e taquicardia ventricular como complicação da granulomatose com poliangiíte em uma paciente. Relato de caso e revisão da literatura / Heart conduction system defects and sustained ventricular tachycardia complications in a patient with granulomatosis with polyangiitis. A case report and literature review

RESUMO A granulomatose com poliangiíte é um raro distúrbio inflamatório sistêmico que se caracteriza por vasculite de pequenas artérias, arteríolas e capilares, associada a lesões granulomatosas necrotizantes. Este artigo relata o caso de uma paciente com diagnóstico prévio de granulomatose com poliangiíte, admitida à unidade de terapia intensiva com quadro de crises convulsivas e instabilidade hemodinâmica em razão de bloqueio atrioventricular completo. Estas manifestações se associaram a múltiplos episódios de taquicardia ventricular sustentada; não havia alterações estruturais cardíacas, nem se detectaram distúrbios hidroeletrolíticos. Na unidade de terapia intensiva, a paciente foi submetida à implantação de marca-passo provisório, imunossupressão com uso de corticosteroides e terapia imunobiológica, resultando em melhora hemodinâmica completa. Distúrbios graves da condução cardíaca em pacientes com granulomatose com poliangiíte são raros, mas associam-se à grande morbidade. O reconhecimento precoce e o uso de intervenções específicas são capazes de prevenir a ocorrência de desfechos desfavoráveis, especialmente na unidade de terapia intensiva.

ABSTRACT Granulomatosis with polyangiitis is a rare systemic inflammatory disorder characterized by vasculitis of the small arteries, the arterioles and the capillaries together with necrotizing granulomatous lesions. This case reports on a young female patient, previously diagnosed with granulomatosis with polyangiitis, who was admitted to the intensive care unit with seizures and hemodynamic instability due to a complete atrioventricular heart block. The event was associated with multiple episodes of sustained ventricular tachycardia without any structural heart changes or electrolyte disturbances. In the intensive care unit, the patient was fitted with a provisory pacemaker, followed by immunosuppression with corticosteroids and immunobiological therapy, resulting in a total hemodynamic improvement. Severe conduction disorders in patients presenting granulomatosis with polyangiitis are rare but can contribute to increased morbidity. Early detection and specific intervention can prevent unfavorable outcomes, specifically in the intensive care unit.

Síndrome de QT largo y taquicardia ventricular en torsade de pointes secundarios a hipopituitarismo: una asociación a tener en cuenta: caso clínico / Long QT syndrome and polymorphic ventricular tachycardia due to hypopituitarism: report of one case

Symptoms of hypopituitarism are usually chronic and nonspecific, but rarely the disease can have acute and life threatening manifestations. We report a 53 years old female with a pituitary adenoma that was admitted to our hospital because of syncope. The electrocardiogram showed sinus bradycardia with a prolonged QT interval. Frequent runs of non-sustained polymorphic ventricular tachycardia were noted on telemetry. The patient had a history of severe acute headaches in the previous days and laboratory tests revealed severe secondary hypothyroidism, adrenal insufficiency and a decrease in pituitary hormones. A magnetic resonance imaging of the head showed changes in the size and contrast enhancement of the adenoma. A diagnosis of hypopituitarism secondary to pituitary apoplexy was made and treatment with hydrocortisone and, subsequently, levothyroxine was started. Hormonal disorders such as hypothyroidism, adrenal insufficiency or hypopituitarism should be considered as unusual causes for reversible cardiomyopathy, long QT syndrome and ventricular arrhythmias.

Dobutamine Stress Echocardiography Safety in Chagas Disease Patients / Segurança do Ecocardiograma sob Estresse com Dobutamina-Atropina em Pacientes com Doença de Chagas

Abstract Background: A few decades ago, patients with Chagas disease were predominantly rural workers, with a low risk profile for obstructive coronary artery disease (CAD). As urbanization has increased, they became exposed to the same risk factors for CAD of uninfected individuals. Dobutamine stress echocardiography (DSE) has proven to be an important tool in CAD diagnosis. Despite being a potentially arrhythmogenic method, it is safe for coronary patients without Chagas disease. For Chagas disease patients, however, the indication of DSE in clinical practice is uncertain, because of the arrhythmogenic potential of that heart disease. Objectives: To assess DSE safety in Chagas disease patients with clinical suspicion of CAD, as well as the incidence of arrhythmias and adverse events during the exam. Methods: Retrospective analysis of a database of patients referred for DSE from May/2012 to February/2015. This study assessed 205 consecutive patients with Chagas disease suspected of having CAD. All of them had their serology for Chagas disease confirmed. Results: Their mean age was 64±10 years and most patients were females (65.4%). No patient had significant adverse events, such as acute myocardial infarction, ventricular fibrillation, asystole, stroke, cardiac rupture and death. Regarding arrhythmias, ventricular extrasystoles occurred in 48% of patients, and non-sustained ventricular tachycardia in 7.3%. Conclusion: DSE proved to be safe in this population of Chagas disease patients, in which no potentially life-threatening outcome was found.

Resumo Fundamento: Até poucas décadas atrás, os pacientes chagásicos eram predominantemente trabalhadores rurais, com baixo perfil de risco para doença obstrutiva coronária. Com a crescente urbanização, passaram a ter os mesmos fatores de risco para doença aterosclerótica que indivíduos não infectados. O ecocardiograma sob estresse com dobutamina (EED) é uma importante ferramenta no diagnóstico de coronariopatia. É referido, porém, como um método potencialmente arritmogênico, mas seguro, em pacientes coronarianos não chagásicos. Entretanto, há insegurança na prática clínica de indicá-lo no paciente chagásico, devido ao potencial arritmogênico já intrínseco nesta cardiopatia. Objetivos: Analisar a segurança do EED em uma população de chagásicos com suspeita clínica de coronariopatia. Métodos: Análise retrospectiva de um banco de dados de pacientes encaminhados para a realização do EED entre maio/2012 e fevereiro/2015. Avaliou-se pacientes consecutivos portadores de doença de Chagas e com suspeita de coronariopatia. Confirmou-se a sorologia para doença de Chagas em todos os pacientes. Resultados: A média etária dos 205 pacientes analisados foi de 64 ± 10 anos, sendo a maioria do sexo feminino (65,4%). Nenhum paciente apresentou eventos adversos significativos, como infarto agudo do miocárdio, fibrilação ventricular, assistolia, acidente vascular encefálico, ruptura cardíaca ou morte. Quanto às arritmias, extrassístoles ventriculares frequentes ocorreram em 48% dos pacientes, taquicardia ventricular não sustentada em 7,3%, bigeminismo em 4,4%, taquicardia supraventricular e taquicardia ventricular sustentada em 1% e fibrilação atrial em 0,5%. Conclusão: O EED mostrou ser um exame seguro nessa população de pacientes chagásicos, onde nenhum desfecho grave foi encontrado.

A Case of Mushroom Poisoning with Russula subnigricans: Development of Rhabdomyolysis, Acute Kidney Injury, Cardiogenic Shock, and Death

Mushroom exposures are increasing worldwide. The incidence and fatality of mushroom poisoning are reported to be increasing. Several new syndromes in mushroom poisoning have been described. Rhabdomyolytic mushroom poisoning is one of new syndromes. Russula subnigricans mushroom can cause delayed-onset rhabdomyolysis with acute kidney injury in the severely poisoned patient. There are few reports on the toxicity of R. subnigricans. This report represents the first record of R. subnigricans poisoning with rhabdomyolysis in Korea, describing a 51-year-old man who suffered from rhabdomyolysis, acute kidney injury, severe hypocalcemia, respiratory failure, ventricular tachycardia, cardiogenic shock, and death. Mushroom poisoning should be considered in the evaluation of rhabdomyolysis of unknown cause. Furthermore, R. subnigricans should be considered in the mushroom poisoning with rhabdomyolysis.

Quais as medicações antiarrítmicas indicadas para o tratamento da taquicardia ventricular no paciente com cardiopatia estrutural? / Which antiarrhythmic drugs are indicated for the management of ventricular tachycardia in patients with structural heart disease?

As taquicardias ventriculares são as arritmias cardíacas com maior potencial de instabilidade clínica e mortalidade cardíaca. Embora possam ocorrer no contexto de pacientes sem cardiopatia estrutural demonstrável, quase sempre ocorrem em coração estruturalmente alterado, com substrato anatômico para reentradas. As alterações cardíacas podem ser isquêmicas e não isquêmica. A distinção entre as etiologias é importante por terem diferentes mecanismos e origens de taquicardia ventricular, que irá determinar a escolha do tratamento adequado das arritmias ventriculares e prevenção de morte súbita. Os principais objetivos no manejo destes pacientes são: a reversão imediata da taquicardia, a prevençãode recorrências e a redução da mortalidade cardiovascular. Atualmente os fármacos com eficácia e perfil de segurança mais utilizados para tratamento de taquicardia ventricular em pacientes com cardiopatia estrutural são os betabloqueadores, amiodarona e sotalol. Com exceção dos betabloqueadores, os antiarrítmicos não possuem a eficácia em manejo primário ou na prevenção de morte súbita demonstrada em estudos clínicos randomizados atuais de forma consistente. Em portadores de cardiodesfibrilador implantável, os antiarrítmicos podem atuar na supressão das taquicardias ventriculares não sustentadas e sustentadas, na lentificação das taquicardias ventriculares com intuito de facilitar a reversão por antitachycardia pacing e prevenir sincopes, além de controlas as taquicardias supraventriculares. Devido aos efeitos colaterais e potencial efeito pró-arrítmico, devem ser utilizados com precaução e com controle adequado...

Ventricular tachycardia is the cardiac arrhythmia with the most potential to result in clinical instability and cardiac mortality. Although it can occur in patients without structural heart disease, it tends to occur where there is underlying heart disease, with anatomical substrate for reentry. It can be subdivided into ischemic and non-ischemic. This is an important distinction, because the mechanisms and origins of ventricular tachycardia may differ between the two, which will determine the choice of treatment for the ventricular arrhythmia and help prevent sudden death. The objective in clinical management of these patients includes: immediate reversal of tachycardia, prevention of relapses, and reducing cardiovascular mortality. The beta-blockers amiodarone and sotalol are currently the most commonly used antiarrhythmic agents, with the best efficacy and safety profile for treating ventricular tachycardia in patients with structural heart disease. With the exception of beta-blockers, currently available antiarrhythmic drugs have not been shown, in randomized clinical trials, to be effective in the primary management of patients with life-threatening ventricular arrhythmias or in the prevention of sudden cardiac death. Inpatients with implantable cardioverter-defibrillators, the potential beneficial effects of antiarrhythmic drugs may be the suppression of non-sustained and sustained ventricular tachycardias, slowing of ventricular tachycardia rate to facilitate pace termination or prevent syncope, and control of atrial tachyarrhythmias. Due to potential adverse effects of antiarrhythmic drugs and the risk of proarrhythmia, close monitoring of the patient is recommended...

Exercise-induced ventricular arrhythmias and vagal dysfunction in Chagas disease patients with no apparent cardiac involvement

INTRODUCTION : Exercise-induced ventricular arrhythmia (EIVA) and autonomic imbalance are considered as early markers of heart disease in Chagas disease (ChD) patients. The objective of the present study was to verify the differences in the occurrence of EIVA and autonomic maneuver indexes between healthy individuals and ChD patients with no apparent cardiac involvement. METHODS : A total of 75 ChD patients with no apparent cardiac involvement, aged 44.7 (8.5) years, and 38 healthy individuals, aged 44.0 (9.2) years, were evaluated using echocardiography, symptom-limited treadmill exercise testing and autonomic function tests. RESULTS : The occurrence of EIVA was higher in the chagasic group (48%) than in the control group (23.7%) during both the effort and the recovery phases. Frequent ventricular contractions occurred only in the patient group. Additionally, the respiratory sinus arrhythmia index was significantly lower in the chagasic individuals compared with the control group. CONCLUSIONS : ChD patients with no apparent cardiac involvement had a higher frequency of EIVA as well as more vagal dysfunction by respiratory sinus arrhythmia. These results suggest that even when asymptomatic, ChD patients possess important arrhythmogenic substrates and subclinical disease. .

Malignant ventricular tachycardia in acromegaly: a case report / Taquicardia ventricular maligna na acromegalia: relato de caso

CONTEXT: In patients with acromegaly, cardiovascular complications are the main cause of death; sudden death has been associated with ventricular tachyarrhythmias. In other patients with life-threatening malignant ventricular tachyarrhythmias, surgical placement of an implantable cardioverter-defibrillator (ICD) has proved highly effective in reducing sudden death rates. CASE REPORT: The present article reports the case of a 50-year-old male acromegalic patient who presented symptoms of syncope induced by ventricular tachycardia. An ICD was surgically implanted and a pituitary adenoma, which was responsible for the acromegaly, was completely removed in the same procedure. The surgery was successful and the ventricular arrhythmias were effectively terminated. During six months of follow-up, no documented arrhythmic episodes occurred. CONCLUSION: In patients with acromegaly, malignant ventricular tachyarrhythmia might be effectively controlled by implantation of an ICD and surgical removal of the pituitary adenoma. .

CONTEXTO: As complicações cardiovasculares são a principal causa de morte em pacientes com acromegalia, e a morte súbita tem sido associada a taquiarritmias ventriculares. Em outros pacientes com risco de vida por taquiarritmias ventriculares malignas, a aplicação cirúrgica de um cardioversor-desfibrilador implantável (CDI) provou ser altamente eficaz na redução das taxas de morte súbita. RELATO DE CASO: O presente artigo relata o caso de um paciente acromegálico de 50 anos de idade e do sexo masculino, que apresentava sintomas de síncope induzida por taquicardia ventricular. Foi implantado cirurgicamente nesse paciente um CDI e na mesma intervenção cirúrgica foi completamente removido um adenoma hipofisário responsável pela acromegalia. A cirurgia foi bem-sucedida e o paciente deixou de sofrer de arritmias ventriculares. Durante seis meses de acompanhamento, não se documentaram, nesse paciente, episódios arrítmicos. CONCLUSÃO: A taquiarritmia ventricular maligna pode ser efetivamente controlada em pacientes com acromegalia pela implantação de um CDI combinado com a remoção cirúrgica do adenoma hipofisário. .

Brugada Syndrome: A Major Cause of Sudden Cardiac Death.

In 1992 a new syndrome was described consisting of syncopal episodes or sudden death in patients with a structurally normal heart and an electrocardiogram characteristic of right bundle branch block with ST segment elevation in leads V1 to V3. Brugada syndrome is an autosomal dominant disorder. It has been shown to be associated with mutations in the gene (SCN5A) that encodes for the sodium ion channel in cardiac myocyte. Over 160 mutations of gene SCN5A have been identifi ed. Th e incidence of the disease is diffi cult to estimate, but it causes sudden deaths of 5 per 10,000 inhabitants per year and involved much more frequently in people of Asian ancestry. Diagnosis can be easily made by means of genetic analysis and ECG. Recent data suggest that loss of the action potential dome in the right ventricular epicardium underlies ST segment elevation seen in this syndrome. Right ventricular epicardium is preferentially aff ected because of the predominance of transient outward current in this tissue. Antiarrhythmic drugs like amiodarone and beta-blockers do not prevent death in symptomatic or asymptomatic individuals. Th ough Implantation of an automatic cardioverter–defi brillator is the only recently proven eff ective therapy; Quinidine has been found to decrease Ventricular fi brillation and could prove to be a secured option of implantable cardioverter–defi brillator. However, researcher set focus on gene therapy that may off er an enduring cure in future years. Th e purpose of this brief review is to record the past highlights that have brought us to our present understanding of Brugada syndrome.

Extreme septal hypertrophy in an adolescent with congenital familial hypertrophic cardiomyopathy

No abstract available.