Evaluation of patients with implantable cardioverter-defibrillator in a Latin American tertiary center.

INTRODUCTION: Despite advancements in implantable cardioverter-defibrillator (ICD) technology, sudden cardiac death (SCD) remains a persistent public health concern. Chagas disease (ChD), prevalent in Brazil, is associated with increased ventricular tachycardia (VT) and ventricular fibrillation (VF) events and SCD compared to other cardiomyopathies. METHODS: This retrospective observational study included patients who received ICDs between October 2007 and December 2018. The study aims to assess whether mortality and VT/VF events decreased in patients who received ICDs during different time periods (2007-2010, 2011-2014, and 2015-2018). Additionally, it seeks to compare the prognosis of ChD patients with non-ChD patients. Time periods were chosen based on the establishment of the Arrhythmia Service in 2011. The primary outcome was overall mortality, assessed across the entire sample and the three periods. Secondary outcomes included VT/VF events and the combined outcome of death or VT/VF. RESULTS: Of the 885 patients included, 31% had ChD. Among them, 28% died, 14% had VT/VF events, and 37% experienced death and/or VT/VF. Analysis revealed that period 3 (2015-2018) was associated with better death-free survival (p = .007). ChD was the only variable associated with a higher rate of VT/VF events (p < .001) and the combined outcome (p = .009). CONCLUSION: Mortality and combined outcome rates decreased gradually for ICD patients during the periods 2011-2014 and 2015-2018 compared to the initial period (2007-2010). ChD was associated with higher VT/VF events in ICD patients, only in the first two periods.

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.

Association between Microvolt T-Wave Alternans and Malignant Ventricular Arrhythmias in Chagas Disease.

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.

Ablação e mapeamento eletroanatômico na displasia arritmogênica ventricular / Ablation and electroanatomical mapping in arrhythmogenic right ventricular dysplasia

Alterações estruturais provenientes da displasia arritmogênica ventricular direita criam um importantesubstrato para focos de taquicardias ventriculares por reentrada. Pacientes com alto risco de desenvolverem essasarritmias são submetidos a tratamento farmacológico associado ao uso de cardiodesfibriladores implantáveis.Porém, em casos mais complexos e refratários, nos quais as terapias adequadas pelo cardiodesfibrilador implantávelsão frequentes, uma nova estratégia se fez necessária, visando à diminuição da morbidade desse subgrupo de pacientes.Estudos recentes demonstram que o mapeamento eletroanatômico associado a ablações por radiofrequênciaendocárdica e epicárdica foi eficaz nesse tratamento adjuvante, diminuindo o número de recorrências dastaquicardias ventriculares.

The structural abnormalities caused by arrhythmogenic right ventricular dysplasia create an importantsubstrate for ventricular tachycardia due to anatomic reentry. Patients at high risk of presenting arrhythmias aresubmitted to drug treatment in combination with the use of implantable cardioverter-defibrillators. However, incomplex and refractory cases, in which appropriate implantable cardioverter-defibrillator therapies are frequent,a new strategy is required to decrease the morbidity of this subgroup of patients. Recent studies demonstrate thatelectroanatomical mapping in combination with endocardial and epicardial radiofrequency catheter ablation is aneffective adjuvant therapy and decreases the rate of ventricular tachycardia recurrence.

Ventricular arrhythmias in Chagas disease.

Sudden death is one of the most characteristic phenomena of Chagas disease, and approximately one-third of infected patients develop life-threatening heart disease, including malignant ventricular arrhythmias. Fibrotic lesions secondary to chronic cardiomyopathy produce arrhythmogenic substrates that lead to the appearance and maintenance of ventricular arrhythmias. The objective of this study is to discuss the main clinical and epidemiological aspects of ventricular arrhythmias in Chagas disease, the specific workups and treatments for these abnormalities, and the breakthroughs needed to determine a more effective approach to these arrhythmias. A literature review was performed via a search of the PubMed database from 1965 to May 31, 2014 for studies of patients with Chagas disease. Clinical management of patients with chronic Chagas disease begins with proper clinical stratification and the identification of individuals at a higher risk of sudden cardiac death. Once a patient develops malignant ventricular arrhythmia, the therapeutic approach aims to prevent the recurrence of arrhythmias and sudden cardiac death by the use of implantable cardioverter defibrillators, antiarrhythmic drugs, or both. In select cases, invasive ablation of the reentrant circuit causing tachycardia may be useful. Ventricular arrhythmias are important manifestations of Chagas cardiomyopathy. This review highlights the absence of high-quality evidence regarding the treatment of ventricular arrhythmias in Chagas disease. Recognizing high-risk patients who require specific therapies, especially invasive procedures such as the implantation of cardioverter defibrillators and ablative approaches, is a major challenge in clinical practice.

Ventricular arrhythmias in Chagas disease

Sudden death is one of the most characteristic phenomena of Chagas disease, and approximately one-third of infected patients develop life-threatening heart disease, including malignant ventricular arrhythmias. Fibrotic lesions secondary to chronic cardiomyopathy produce arrhythmogenic substrates that lead to the appearance and maintenance of ventricular arrhythmias. The objective of this study is to discuss the main clinical and epidemiological aspects of ventricular arrhythmias in Chagas disease, the specific workups and treatments for these abnormalities, and the breakthroughs needed to determine a more effective approach to these arrhythmias. A literature review was performed via a search of the PubMed database from 1965 to May 31, 2014 for studies of patients with Chagas disease. Clinical management of patients with chronic Chagas disease begins with proper clinical stratification and the identification of individuals at a higher risk of sudden cardiac death. Once a patient develops malignant ventricular arrhythmia, the therapeutic approach aims to prevent the recurrence of arrhythmias and sudden cardiac death by the use of implantable cardioverter defibrillators, antiarrhythmic drugs, or both. In select cases, invasive ablation of the reentrant circuit causing tachycardia may be useful. Ventricular arrhythmias are important manifestations of Chagas cardiomyopathy. This review highlights the absence of high-quality evidence regarding the treatment of ventricular arrhythmias in Chagas disease. Recognizing high-risk patients who require specific therapies, especially invasive procedures such as the implantation of cardioverter defibrillators and ablative approaches, is a major challenge in clinical practice.

Preditores para desenvolvimento de arritmia ventricular maligna na cardiopatia chagásica: protocolo de estudo caso-controle / Predictors for development of malignant ventricular arrhythmia in Chagas heart disease: case-control study protocol

Introdução: A doença de Chagas acomete três a quatro milhões de brasileiros. O curso clínico da doença é extremamente variável e aproximadamente um terço dos pacientes infectados desenvolve doença cardíaca potencialmente letal, incluindo arritmias ventriculares malignas e insuficiência cardíaca. Os mecanismos eletrofisiológicos mais frequentemente envolvidos na morte súbita nos chagásicos são representados pela taquicardia ventricular e fibrilação ventricular. Objetivo: Descrever protocolo de estudo que busca preditores da evolução para a morte por arritmia na doença de Chagas. Metodologia: Está sendo estudada a associação de arritmias malignas com marcadores relacionados à repolarização ventricular (microalternância de onda T e intervalo Tpeak a Tend - TpTe) e aqueles relacionados ao parasitismoe à inflamação, além dos marcadores clássicos de risco na cardiopatia chagásica. Trata-se de estudo do tipo caso-controle e a amostra estimada foi de 240 pacientes chagásicos, sendo 120 casos (arritmia ventricular) e 120 controles (sem arritmia ventricular). Esses pacientes são submetidos a: entrevista médica e exame físico; eletrocardiograma, com medida do intervalo TpTe na derivação V5; ecocardiograma, holter de 24h e teste ergométrico; dosagem de TNF, sTNFR1, sTNFR2, IL-6, MCP-1 e RANTES, BDNF, NT-proBNP e de PCR para Trypanosoma cruzi. Resultados e conclusões: O presente estudo pretende fornecer informações acerca da fisiopatologia e mecanismos patogenéticos das arritmias malignas nadoença de Chagas. A identificação de marcadores não invasivos de risco para morte súbita tornará possível a identificação de subgrupos que se beneficiam do implante de CDI.

Introduction: Chagas disease affects three to four million Brazilians. The clinical course of the disease is extremely variable, and about one third of infected patients develop life-threatening heart disease, including malignant ventricular arrhythmias and heart failure. The electrophysiological mechanisms most frequently associated with sudden death in Chagasdisease are represented by ventricular tachycardia and ventricular fibrillation. Objective: To study predictors of progression to death from arrhythmia in Chagas disease. Methodology : It is being studied the association of markers of malignant arrhythmias related to ventricularrepolarization ( micro - alternation of the T wave interval and Tpeak to Tend - TpTe ) and those related to parasitism and inflammation, in addition to the classical risk markers in Chagas heart disease. This is a case-control study and the sample was estimated at 240 chagasic patients, 120 cases (ventricular arrhythmias ) and 120 controls (without ventricular arrhythmias) These patients are being subjected to: medical interview and physical examination; Electrocardiogram, with measurement TpTe interval in lead V5; echocardiogram, Holter 24-hour stress test; determination of TNF sTNFR1, sTNFR2, IL-6, MCP -1 and RANTES, BDNF, NT -proBNP and PCR for Trypanosoma cruzi. Results and Conclusions: The present study aims to provide information about the pathophysiology and pathogenetic mechanisms of malignant arrhythmias in Chagas disease. The identification of non-invasive markers of risk for arrhythmic death will make possible toidentify patients who benefit from ICD implantation.

Mortality prediction in Chagas heart disease.

Chagas disease continues to be an important cause of cardiac disease in many countries of Latin America. Dilated cardiomyopathy constitutes the more severe manifestation and main cause of death in the disease. Typical clinical presentations include three basic syndromes: heart failure, cardiac arrhythmia and thromboembolism. The identification of markers related to the progression of Chagas heart disease is relevant for appropriate patient management. The most important predictors of death are New York Heart Association functional class, left ventricular systolic dysfunction and nonsustained ventricular tachycardia, which reflect the severity of myocardial damage. Several other potential prognostic factors have recently been reported. Scores for mortality prediction using a combination of prognostic variables have contributed to overall improvement in risk stratification in the setting of Chagas disease.

Efeito histológico causado na parede posterior da cavidade abdominal pela lavagem com solução salina 0.9 por cento aquecida a diferentes temperaturas: estudo experimental em ratos / Histological effects caused in the posterior abdominal cavity wall by washing with 0.9 percent saline solutions heated at different temperatures: experimental study in rats

A lavagem da cavidade abdominal com solução salina 0,9 por cento aquecida é uma prática comum em cirurgia geral, mas, geralmente, não há um controle adequado da sua temperatura, sendo por vezes introduzida na cavidade abdominal a temperaturas elevadas, possivelmente causando lesões no nível celular. O objetivo do trabalho é estudar a célula da parede posterior da cavidade abdominal de ratos após o tratamento desta com solução salina 0,9 por cento aquecida a graus diversos. Foram utilizados 28 ratos divididos em três grupos com 9 animais cada e um rato controle. O grupo A foi tratado com solução salina 0,9 por cento a 37ºC, o grupo B a 45ºC e o grupo C a 60ºC. O rato controle não recebeu tratamento com solução salina 0,9 por cento. Em todos os grupos a solução salina 0,9 por cento permaneceu na cavidade durante 1 minuto. Exame histopatológico revelou que no rato controle e nos grupos A e B as fibras musculares e as estriações celulares estavam intactas. No grupo C, no entanto, observaram-se princípios de degeneração celular. Como conclusão ressalta-se a importância de um controle efetivo da temperatura da solução salina 0,9 por cento a ser introduzida na cavidade abdominal de ratos para prevenir um trauma térmico no nível celular.