QTc, Tp-e Interval and Tp-e/QTc Ratio in Patients with Hypocalcemia-case Control Study

Abstract Background: To the best of our knowledge, there are studies related to QT and QTc interval in patients with hypocalcemia, but there are no studies evaluating T wave peak and end interval (Tp-e interval), Tp-e/QT and Tp-e/QTc ratios used to evaluate cardiac arrhythmia risk and ventricular repolarization changes rates. Objectives: Therefore, we aimed to investigate whether there is a change in Tp-e interval, Tp-e/QT and Tp-e/QTc ratios in patients with hypocalcemia. Methods: Retrospectively, 29 patients with hypocalcemia in the emergency department were included in the study. Twenty-nine patients with similar age and sex distribution were included in the study as the control group. All patients underwent 12-lead electrocardiography (ECG). In addition to routine measurements, Tp-e interval, Tp-e/QT and Tp-e/QTc ratios were measured on ECG. The study data were grouped as patients with and without hypocalcemia. Results: The mean age of the patients was 66.24 ± 4.95 years. QTc interval, Tp-e interval and Tp-e/QTc values were found to be significantly higher in patients with hypocalcemia (p <0.001 for each). QTc interval, Tp-e interval and Tp-e/QTc ratio showed a significant negative correlation with calcium levels. Conclusion: Tp-e interval and Tp-e/QTc ratios are significantly increased in patients with hypocalcemia compared to those without hypocalcemia and this can be used more effectively in the follow-up of cardiac fatal arrhythmias.

Outcomes of the Conversion of the Fontan-Kreutzer Operation to a Total Cavopulmonary Connection for the Failing Univentricular Circulation / Resultados da Conversão da Cirurgia de Fontan-Kreutzer para Cavo-Pulmonar Total Devido Falência da Circulação Univentricular

Abstract Background: The Fontan-Kreutzer procedure (FK) was widely performed in the past, but in the long-term generated many complications resulting in univentricular circulation failure. The conversion to total cavopulmonary connection (TCPC) is one of the options for treatment. Objective: To evaluate the results of conversion from FK to TCPC. Methods: A retrospective review of medical records for patients who underwent the conversion of FK to TCPC in the period of 1985 to 2016. Significance p < 0,05. Results: Fontan-type operations were performed in 420 patients during this period: TCPC was performed in 320, lateral tunnel technique in 82, and FK in 18. Ten cases from the FK group were elected to conversion to TCPC. All patients submitted to Fontan Conversion were included in this study. In nine patients the indication was due to uncontrolled arrhythmia and in one, due to protein-losing enteropathy. Death was observed in the first two cases. The average intensive care unit (ICU) length of stay (LOS) was 13 days, and the average hospital LOS was 37 days. A functional class by New York Heart Association (NYHA) improvement was observed in 80% of the patients in NYHA I or II. Fifty-seven percent of conversions due to arrhythmias had improvement of arrhythmias; four cases are cured. Conclusions: The conversion is a complex procedure and requires an experienced tertiary hospital to be performed. The conversion has improved the NYHA functional class despite an unsatisfactory resolution of the arrhythmia.

Resumo Fundamento: O procedimento de Fontan-Kreutzer (FK) foi amplamente realizado no passado, mas a longo prazo gerou muitas complicações, resultando em falha na circulação univentricular. A conversão para conexão cavopulmonar total (CCPT) é uma das opções de tratamento. Objetivo: Avaliar os resultados da conversão de FK para CCPT. Métodos: Revisão retrospectiva de prontuários de pacientes submetidos à conversão de FK para CCPT no período de 1985 a 2016. Significância p < 0,05. Resultados: Operações do tipo Fontan foram realizadas em 420 pacientes durante este período: CCPT foi realizada em 320, técnica de túnel lateral em 82 e FK em 18. Dez casos do grupo FK foram eleitos para conversão em CCPT. Todos os pacientes submetidos à conversão de Fontan foram incluídos neste estudo. Em nove pacientes, a indicação deveu-se a arritmia não controlada e em um devido à enteropatia perdedora de proteínas. A morte foi observada nos dois primeiros casos. O tempo médio de internação na unidade de terapia intensiva (UTI) foi de 13 dias e o tempo médio de internação hospitalar foi de 37 dias. Uma classe funcional pela melhora da New York Heart Association (NYHA) foi observada em 80% dos pacientes em NYHA I ou II. Cinquenta e sete por cento das conversões devido a arritmias tiveram melhora das arritmias; quatro casos foram curados. Conclusões: A conversão é um procedimento complexo e requer que um hospital terciário experiente seja realizado. A conversão melhorou a classe funcional da NYHA, apesar de uma resolução insatisfatória da arritmia.

Association between premature ventricular complexes during exercise, long-term occurrence of life-threatening arrhythmia and mortality / Asociación entre ectopia ventricular en ejercicio, la ocurrencia de arritmias potencialmente mortales y mortalidad a largo plazo

Abstract Objective: Exercise-induced premature ventricular complexes (EiPVCs) are often considered as benign arrhythmias, although they are associated with a high risk of all-cause death in the general healthy population. However, an intermediate pathophysiological process remains unclear, particularly in patients with known cardiovascular disease. The aim of this study was to find an association between EiPVCs, the occurrence of life-threatening ventricular arrhythmias (LACO), and all-cause mortality in patients with cardiovascular disease. Methods: This was an observational study of a cohort of patients with coronary artery disease (CAD) or idiopathic cardiomyopathy (ICM). Stress testing was performed as a part of the routine cardiovascular evaluation. The occurrence of EiPVCs was evaluated during exercise testing (ET). At follow-up, long-term occurrence of LACO was evaluated. A bivariate and multivariate analysis was performed. Results: Out of the total of 1442 patients analysed, 700 (49%) had EiPVCs. During 14 years of following-up after ET, 106 LACO outcomes were observed. Long-term all-cause mortality was 4% (n = 61). A bivariate analysis showed that patients with EiPVCs had an increased risk for LACO (RR = 2.81, 95% CI; 1.9---4.3, P < .001), and for mortality (RR = 2.1, CI95% 1.2---3.4, P < .01). Occurrence of LACO was also associated with a higher mortality risk (RR = 5.7, 95% CI; 3.4---9.4, P < .001). After a post hoc analysis, LACO remained as a highly predictive variable for mortality. Conclusion: Patients with EiPVCs have a high risk of LACO and all-cause mortality. The presence of LACO could be an intermediate stage between EiPVCs and mortality in subjects with cardiovascular disease.

Resumen Objetivo: La extrasistolia ventricular inducida por ejercicio (EVIE) suele considerarse una arritmia benigna, sin embargo, ha sido asociada a mayor mortalidad en población general. Hasta hoy no se ha encontrado el proceso fisiopatológico involucrado, particularmente en pacientes con enfermedad cardiovascular. El objetivo del estudio fue establecer una asociación entre EVIE con la ocurrencia de arritmias ventriculares potencialmente malignas (APM) y letalidad a largo plazo, en sujetos con enfermedad cardiovascular. Método: Estudiamos una cohorte de pacientes con enfermedad coronaria o miocardiopatía dilatada, que realizaron una prueba de ejercicio al inicio del estudio. Inicialmente evaluamos la ocurrencia de EVIE, APM y letalidad a largo plazo y posteriormente se realizó un estudio bivariable y multivariable. Resultados: Se incluyeron 1,442 pacientes de los cuales 700 presentaron EVIE (49%). Durante 14 an˜os de seguimiento, 106 sujetos presentaron APM y la mortalidad total fue de 61 casos (4%). El estudio bivariable mostró que aquellos pacientes con EVIE tuvieron un riesgo de presentar APM de 2.81 (IC95% de 1.9 a 4.3, p < 0.001) y de mortalidad de 2.1 (IC95% de 1.2 a 3.4, p < 0.01). Los individuos con APM tuvieron mayor riesgo de mortalidad (RR= 5.7, IC95% de 3.4 a 9.4, p < 0.001). Después de un análisis multivariable, la APM continuó siendo una variable altamente predictiva de mortalidad. Conclusión: Los pacientes con EVIE tienen un riesgo elevado de presentar APM y de mortalidad a largo plazo. Los resultados sugieren que las APM podrían representar un estado intermedio entre la presencia de EVIE y la mortalidad en pacientes con enfermedad cardiovascular.

Heart Transplantation in Pediatric Patients: Twelve-Year Experience of the Asan Medical Center

Heart transplantation is a standard treatment for end-stage heart disease. Pediatric heart transplantation, however, is not frequently performed due to the shortage of pediatric heart donors. This is the first report of pediatric heart transplantation in Korea. Our retrospective study included 37 patients younger than 18 yr of age who underwent heart transplantation at Asan Medical Center between August 1997 and April 2009. Preoperative diagnosis was either cardiomyopathy (n = 29, 78.3%) or congenital heart disease (n = 8, 22.7%). Mean follow up period was 56.9 +/- 44.6 months. There were no early death, but 7 late deaths (7/37, 18.9%) due to rejection after 11, 15, 41 months (n = 3), infection after 5, 8, 10 months (n = 3), suspicious ventricular arrhythmia after 50 months (n = 1). There was no significant risk factor for survival. There were 25 rejections (25/37, 67.6%); less than grade II occurred in 17 patients (17/25, 68%) and more than grade II occurred in 8 patients (8/25, 32%). Actuarial 1, 5, and 10 yr survival was 88.6%, 76.8%, and 76.8%. Our midterm survival of pediatric heart transplantation showed excellent results. We hope this result could be an encouraging message to do more pediatric heart transplantation in Korean society.

Anticoagulação e antiagregação plaquetária em pacientes com fibrilação atrial: passado, presente e futuro / Anticoagulation and platelet antiagregation in patients with atrial fibrillation: past, present and future

A prevenção de acidente vascular cerebral e embolia sistêmica é um paradigma no tratamento da fibrilação atrial. Embora a varfarina seja o anticoagulante oral mais utilizado na prática clínica em pacientes com fibrilação atrial, esse medicamento apresenta significantes limitações que impedem seu uso apropriado na profilaxia do acidente vascular cerebral em pacientes elegíveis para tal. Consequentemente, muitos estudos estão em andamento para se encontrar uma alternativa à varfarina. Recentemente, o estudo RE-LY demonstrou que o dabigatran (um novo anticoagulante oral da classe dos inibidores diretos da trombina) é bem tolerado e é uma alternativa efetiva à varfarina para pacientes com fibrilação atrial crônica e pelo menos um fator de risco adicional para acidente vascular cerebral. Porém como o dabigatran apresenta alguns incovenientes, multiplas escolhas terapêuticas talvez sejam necessárias para suprir as necessidades de uma crescente e diversa população com fibrilação atrial. Os inibidores orais e diretos do fator Xa são potencialmente bem tolerados e substitutos efetivos para a varfarina. Esses agentes não necesitam de cofatores para sua ação e oferecem inibição seletiva em etapa crítica da amplificação na cascata de coagulação. Vários agentes dessa nova classe de anticoagulantes estão atualmente em desenvolvimento em estudos fase I, fase II e fase III. Resultados recentes demonstraram que esses anticoagulantes têm perfis farmacocinéticos e farmacodinâmicos...

Prevention of stroke and systemic embolism is a paradigm in the management of atrial fibrillation. Although warfarin is the most used anticoagulant in patients with atrial fibrillation, it has significant limitations which have not enabled its appropriate use in the prophylaxis of stroke in eligible patients. Consequently, there are many ongoing studies to find an alternative to warfarin. Recently, the RE-LY trial demonstrated that dabigatran (a new oral direct thrombin inhibitor) is a well tolerated and effective alternative to warfarin for patients with chronic atrial fibrillation and at least one additional risk factor for stroke. However, dabigratran has some drawbacks and therefore, multiple therapeutic options may be required to meet the needs of a rapidly growing and diverse atrial fibrillation patient population. Oral direct Xa factor inhibitors are potentially well tolerated and effective replacements for warfarin. These agents do not require cofactors and offer selective inhibition at a critical step of amplification in the coagulation cascade. Several agents of this new class of anticoagulants are currently undergoing phase I, II, and III trials. Early results suggest that these novel anticoagulants have favorable pharmacokinetic and pharmacodynamic profiles and do not require therapeutic monitoring. Two oral direct Xa factor inhibitors are emerging from phase II trials (betrixaban and YM150) and three are being evaluated in phase III trials (apixaban, edoxaban, and rivaroxaban) for the prevention of stroke and systemic embolism in patients with atrial fibrillation. Phase III trials of apixaban and rivaroxaban have concluded enrollment and are in the follow-up phase. Given the growing population of patients with atrial fibrillation, there is a great interest in finding new therapies for oral anticoagulation. Oral direct Xa factor inhibitors along with oral direct thrombin inhibitors may offer several promising alternatives to warfarin therapy.

Portadores de CDI com limiar de desfibrilação elevado: evolução clínica e alternativas terapêuticas / ICD patients with elevated defibrillation threshold: clinical behavior and therapeutic alternatives

FUNDAMENTO: A programação ideal da energia de choque do CDI deve ser pelo menos 10 J acima do limiar de desfibrilação (LDF), necessitando de técnicas alternativas quando o LDF é elevado. OBJETIVO: Avaliar o comportamento clínico dos portadores de CDI com LDF>25 J e a eficácia da terapêutica escolhida. MÉTODOS: Foram selecionados portadores de CDI, entre janeiro de 2000 e agosto de 2004 (banco de dados prospectivo), com LDF>25 J intra-operatório, e analisaram-se: características clínicas, FEVE, resgate de eventos arrítmicos pelo CDI e óbitos. RESULTADOS: dentre 476 pacientes, 16 (3,36 por cento) apresentaram LDF>25J. Idade média de 56,5 anos, sendo 13 pacientes (81 por cento) do sexo masculino. Quanto à cardiopatia de base 09 eram chagásicos, 04 isquêmicos e 03 com etiologia idiopática. A FEVE média dos pacientes foi 37 por cento e 94 por cento utilizavam amiodarona. O seguimento médio foi de 25,3 meses. Em 02 pacientes com LDF > Choque Máximo (CM), foi necessário implante de eletrodo de choque adicional (array), sendo mantido programação com CM em zona de FV (>182bpm) nos demais. Durante o seguimento 03 pacientes apresentaram 67 terapias de choque apropriadas (TCA) com sucesso. Ocorreram 07 óbitos sendo 5 por causas não cardíacas e 2 por insuficiência cardíaca avançada. Os pacientes que foram a óbito apresentaram níveis de LDF maiores (p=0,0446), entretanto sem relação com a causa dos mesmos tendo em vista que não ocorreram TCA sem sucesso. CONCLUSÃO: Nessa coorte de pacientes com CDI, a ocorrência de LDF elevado foi baixa, implicando terapêuticas alternativas. Houve associação com disfunção ventricular grave, entretanto sem correlação com as causas de óbito.

BACKGROUND: The ideal programming of the implantable cardioverter defibrillator (ICD) shock energy should be at least 10J above the defibrillation threshold (DFT), requiring alternative techniques when the DFT is elevated. OBJECTIVE: To assess the clinical behavior of ICD patients with DFT>25J and the efficacy of the chosen therapy. METHODS: Patients who had undergone ICD implantation between Jan/00 and Aug/04 (prospective database) and presented intraoperative DFT>25J were selected. The analyzed variables were: clinical characteristics, LVEF, rescue of arrhythmic events from ICD and causes of deaths. RESULTS: among 476 patients, 16 (3.36 percent) presented DFT>25J. The mean age was 56.5 years, and 13 patients (81 percent) were men. According to the baseline cardiomyopathy, 09 patients had Chagas' disease, 04 had ischemic cardiomyopathy and 03 had idiopathic cardiomyopathy. Mean LVEF was 0.37 and amiodarone was used by 94 percent of the patients. Mean follow-up (FU) period was 25.3 months. DFT was higher than maximum energy shock (MES) in 2 patients and it was necessary to implant an additional shock electrode (array). It was programmed MES in ventricular fibrillation zone of ICD therapy in the other patients. In the FU, 03 patients had 67 successful appropriate shock therapies (AST). There were 05 noncardiac and 02 heart failure deaths. The patients who died showed higher DFT levels (p=0.044) without correlation with death because there wasn't unsuccessful AST. CONCLUSION: In this cohort of ICD patients, the occurrence of elevated DFT (>25J) was low, leading to alternative therapies. There was an association with severe ventricular dysfunction, although without correlation to the causes of death.

Preventing tomorrow's sudden cardiac death in epilepsy today: what should physicians know about this?: [review]

Approximately 1 percent of the population has epilepsy, the most common neurological disorder. Moreover, people with epilepsy are more likely to die prematurely than those without epilepsy, and the most common epilepsy-related category of death is sudden unexpected death in epilepsy (SUDEP). Information concerning risk factors for SUDEP is conflicting, but potential risk factors include: age, early onset of epilepsy, duration of epilepsy, uncontrolled seizures, seizure frequency, number of antiepileptic drugs and winter temperatures. Additionally, the cause of SUDEP is still unknown; however, the most commonly suggested mechanisms are cardiac abnormalities during and between seizures. This review discusses the epidemiology, risk factors, etiology, and preventative measures in the management of SUDEP.

Incidencia y comportamiento clínico de las arritmias en pacientes con corrección quirúrgica de cardiopatías congénitas / Incidence and clinical features of arrhythmias after surgical treatment of congenital heart disease

Congenital heart disease is associated with arrhythmias. Not only the congenital anatomic component but also the greater arrhythmogenic substrate related to surgical procedures is associated with the increased incidence of arrhythmias in these patients. In pediatric cardiology the study of these phenomena is becoming important and one factor associated with it is the longer follow up, which varies depending on the type of heart disease and arrhythmia. With the same impact, there are daily breakthroughs in diagnostic and treatment through pharmacological and interventional means. The incidence of arrhythmias in post-surgical patients with congenital heart disease is in constant increment, and this is related to the constant increment in the procedures, variety and frequency, as well as the long-term survival.

Utilidad del desfibrilador automático implantable en la prevención de muerte súbita: resultados de la medicina basada en evidencia / Usefulness of the implantable cardiodefibrillator (ICD) in the prevention of sudden death: results of evidence based medicine

A great percentage of patients who have suffered a myocardial infarction have ventricular left dysfunction. In agreement with the different prospective studies, many of these patients will have an event of ventricular arrhythmias that does them candidates for receiving a strategy of primary or secondary prevention with an ICD. The same studies have showed a significant reduction in mortality with the therapy of the ICD compared with the conventional therapy what demonstrates the balance cost - benefit in favor of the use of these devices in long periods of follow-up. The benefits of mortality with the use of the therapy with ICD at the primary prevention are at least so good as those of the secondary prevention of agreement to the results of different prospective studies.

Gender differences in in-hospital mortality and mechanisms of death after the first acute myocardial infarction

There are conflicting data about gender differences in short-term mortality after acute myocardial infarction [AMI] after adjusting for age and other prognostic factors. Therefore, we investigated the risk profile, clinical presentation, in-hospital mortality and mechanisms of death in women and men after the first AMI. The data were obtained from a chart review of 3382 consecutive patients, 1184 [35%] women [69.7 +/- 10.9 years] and 2198 [65%] men [63.5 +/- 11.8 years] with a first AMI. The effect of gender and its interaction with age, risk factors and thrombolytic therapy on overall mortality and mechanisms of death were examined using logistic regression. Unadjusted in-hospital mortality was higher in women [OR 1.77, 95% Cl 1.47-2.15]. Adjustment that included both age only and age and other base-line differences [hypertension, diabetes mellitus, hypercholesterolemia, smoking, AMI type, AMI site, mean peak CK value, thrombolytic therapy] decreased the magnitude of the relative risk of women to men but did not eliminate it [OR 1.26, 95% Cl 1.03-1.54 and OR 1.31 95% Cl 1.03-1.66, respectively]. Multivariate analysis revealed that female gender was an independent predictor of in-hospital mortality after the first AMI. Women were dying more often because of mechanical complications-refractory pulmonary edema and cardiogenic shock [P=0.02] or electromechanical dissociation [P=0.03], and men were dying mostly by arrhythmic death, primary ventricular tachycardia/fibrillation [P=0.002]. Female gender was independently associated with mechanical death [OR 1.56, 95% Cl 1.35-2.58; P=0.01] and anterior AMI was independently associated with arrhythmic death [OR 0.54,95% Cl 0.34-0.86; P=0.01]. Our results demonstrate significant differences in mechanisms of in-hospital death after the first AMI in women and men, suggesting the possibility that higher in-hospital mortality in women exists primarily because of the postponing AMI death due to the gender-re-lated differences in susceptibility to cardiac arrhythmias following acute coronary events

Revascularizaçäo do miocárdio com endarterectomia da artéria coronária: estratificaçäo dos fatores de risco de mortalidade imediata / Myocardial revascularization with coronary endarterectomy: stratification of risk factors for early mortality

OBJECTIVE: To determine the risk factors for mortality related to myocardial revascularization when performed in association with coronary endarterectomy. METHODS: We assessed retrospectively 353 patients who underwent 373 coronary endarterectomies between January '89 and November '98, representing 3.73 percent of the myocardial revascularizations in this period of time. The arteries involved were as follows: right coronary artery in 218 patients (58.45 percent); left anterior descending in 102 patients (27.35 percent); circumflex artery in 39 patients (10.46 percent); and diagonal artery in 14 patients (3.74 percent). We used 320 (85.79 percent) venous grafts and 53 (14.21 percent) arterial grafts. RESULTS: In-hospital mortality among our patients was 9.3 percent as compared with 5.7 percent in patients with myocardial revascularizations without endarterectomy (p=0.003). Cause of death was related to acute myocardial infarction in 18 (54.55 percent) patients. The most significant risk factors for mortality identified were as follows: diabetes mellitus (p=0.001; odds ratio =7.168), left main disease (<0.001; 9.283), female sex (0.01; 3.111), acute myocardial infarction (0.02; 3.546), ejection fraction <35 percent (<0.001; 5.89), and previous myocardial revascularization (<0.001; 4.295). CONCLUSION: Coronary endarterectomy is related to higher mortality, and the risk factors involved are important elements of a poor outcome

Novas idéias sobre os mecanismos eletrofisiológicos da fibrilaçäo atrial e suas implicaçöes terapêuticas / Electrophysiologic mechanisms of atrial fibrillation: new concepts and therapeutic implications

A fibrilaçäo atrial (FA) é a arritmia cardíaca sustentada mais frequente na prática clínica e está associada a morbidade e mortalidade significativas. Nos últimos anos, houve grandes progressos no entendimento dos vários mecanismos eletrofisiológicos envolvidos nas gênese e perpetuaçäo dessa arritmia. Observou-se que a FA pode ser desencadeada por mecanismos focais, localizados principalmente nas veias pulmonares. Evidências experimentais e clínicas sugerem que a FA promove alteraçöes anatômicas e elétricas nos átrios que favorecem a sua perpetuaçäo. Esses novos conceitos têm redirecionado a abordagem terapêutica dos pacientes com FA. Vários métodos näo farmacológicos para o tratamento da FA estäo em desenvolvimento, incluindo ablaçäo por cateter com radiofrequência, marcapassos com dupla estimulaçäo atrial e desfibriladores atriais implantáveis. Apesar de promissores, o valor e a aplicabilidade clínica desses métodos ainda näo foram definidos. A associaçäo de modalidades terapêuticas com o objetivo de obter um efeito cinérgico pode contribuir favoravelmente para o tratamento da FA. Este artigo revisa os novos conceitos fisiopatológicos da FA e analisa o impacto desses avanços na abordagem terapêutica de pacientes com essa arritmia

Cirurgia do labirinto: técnica e resultados / The maze operation: technique and results

A fibrilaçäo atrial é a arritmia sustentada mais frequentemente encontrada na prática clínica e está associada a significativa morbi-mortalidade. A irregularidade do ritmio cardíaco causa desconforto, a perda do sincronismo atrioventricular leva a alteraçöes hemodinâmicas e a extase sanguínia atrial aumenta o risco de tromboembolismo. Com o objetivo de controlar e, preferentemente promover a cura de pacientes com fibrilaçäo atrial paroxística ou crônica, três técnicas cirúrgicas (o isolamento do átrio esquerdo, a operaçäo do corredor e a cirurgia do labirinto) foram propostas nas últimas duas décadas. A técnica do isolamento do átrio esquerdo e a cirurgia do corredor, apesar de restabelecerem o ritmo sinusal, näo reduzem o risco de tromboembolismo, pois o átrio esquerdo ou ambos átrios continuam fibrilando. No momento, a técnica cirúrgica mais utilizada para o tratamento da fibrilaçäo atrial refratária é a cirurgia do labirinto, desenvolvida por Cox esta técnica, inicialmente realizada apenas em pacientes com fibrilaçäo atrial isolada, apesar de controlar a arritmia na maioria dos pacientes, acompanhou-se incidência inaceitável de imcopetência cronotrópica. Com o objetivo de superar este problema, a técnica original (Cox I) foi modificada duas vezes, culminando na técnica conhecida como Cox III, associada a uma maior obtençäo de ritmo regular no pós-operatório, melhor funçäo de transporte atrial, menor recorrência da arritmia e menor necessidade de implante de marcapasso definitivo. Neste artigo, säo descritas a evoluçäo e os resultados do tratamento cirúrgico da fibrilaçäo atrial

Procedimentos ablativos por cateter no tratamento da fibrilaçäo atrial / Catheter ablation for the treatment of atrial fibrillation

A alta prevalência da fibrilaçäo atrial, assim como sua morbidade e mortalidade, a ausência de terapêutica farmacológica segura e efetiva, e o entendimento cada vez maior de suas bases fisiopatológicas, tem estimulado o desenvolvimento de terapêuticas näo farmacológicas para a abordagem desta arritmia. Nos pacientes que apresentam fibrilaçäo atrial com alta resposta ventricular e refratária a drogas, a ablaçäo da junçäo AV, com implante de marcapasso, tem se mostrado uma alternativa efetiva, no entanto, restrita ao controle da freqüência cardíaca. A modificaçäo do nó AV pode ser utilizada como primeira tentativa para o controle da freqüência, antes da opçäo definitva, representada pela ablaçäo da junçäo AV. As técnicas propostas de ablaçäo por cateter, baseadas na cirurgia de Cox, carecem de maior esclarecimentos da fisiopatologia da fibrilaçäo atrial, assim como de avanços tecnológicos relacionados aos cateteres e as novas fontes de energia, para que se desenvolvam técnicas mais eficazes, seguras, e de maior aplicabilidade prática. A ablaçäo de focos deflagradores da fibrilaçäo atrial, embora em fase de investigaçäo em relaçäo a sua real eficácia e margem de complicaçöes, traz a expectativa de cura da chamada fibrilaçäo atrial focal

Aspectos epidemiológicos, etiologia e classificaçäo da fibrilaçäo atrial / Epidemiology, etiology and classification of atrial fibrilation

A fibrilaçäo atrial (FA) é a arritmia sustentada mais frequente. Sua prevalencia é rara antes dos 40 anos, mas, aumenta progressivamente a partir desta idade. Como a proporçäo de idosos está crescendo, a sua ocorrência será cada vez mais frequente. O seu aparecimento está relacionado a aumento de duas vezes na mortalidade e de 5 vezes nos acidentes vasculares cerebrais. As causas mais frequentes säo a cardiopatia hipertensiva, a insuficiência cardíaca, as valvopatias mitrais e a insuficiência coronariana. Outras causas säo a tiretoxicose, doenças pulmonares obstrutivas, disturbios eletrolíticos, strees, álcool cardiomiopatia hipertrófica, Wolf-Parkinson-White, valvopatia aórtica, cardiopatia chagásica, doença do nó sinusal, etc. Cerca de 15 a 30 'por cento' näo apresentam causas definidas (FA isolada). Näo existe uma classificaçäo consensual para a FA. De acordo com o tempo de evoluçäo a FA pode ser "de início recente", "única", "paroxística". De acordo com a etiologia ela pode ser "reumática ou näo reumática", "vagal ou adrenérgica", "com cardiopatia estrutural ou isolada".

Trombolisis tardía y estabilidad eléctrica en el infarto agudo del miocardio: importancia del flujo colateral / Late thrombolysis and electrical stability in acute myocardial infarction. Role of the collateral flow

En 249 pacientes con primer infarto del micardio. Grupo 1. Sin trombolítico, n=119; 2. Trombolisis antes de 6 horas, n=80 y grupo 3. Trombolisis entre las 6 y 12 horas, n=50. Se evaluó la presencia de arritmias malignas en el primer año de sobrevida, la variabilidad de la frecuencia cardiaca, el flujo coronario anterógrado (TIMI) y el flujo coronario colateral (1. Pobre: Rentrop, grados 0-2 y 2. Adecuada: Rentrop grado 3). Los grupos 2 y 3 tuvieron mejor flujo TIMI y colateral que el grupo 1 (p<0.001). La banda espectral de alta frecuencia y la relación entre las bandas de baja y alta frecuencia estuvieron más alteradas en el grupo 1 (p<0.05). El análisis de consolidación conjuntiva mostró que los pacientes con TIMI 0-2 y pobre flujo colateral tuvieron mayores epidosios de arritmias malignas que los pacientes con TIMI 0-2 con adecuado flujo colateral (17/138-12.3 por ciento-vs 0/14-0 por ciento-). Los pacientes con TIMI 0-2 y pobre flujo colateral presentaron mayor mortalidad por eventos arrítmicos que los tenían TIMI 3 o TIMI 0-2 con adecuado flujo colateral (x²=7.22, p=0.028), independientemente del tratamiento trombolítico

Morte súbita por arritmia / Sudden cardiac death to an arrhythmic event

A morte súbita ocorre como consequência de várias doenças e, dada sua prevalência, constitui importante problema de saúde pública. A discussäo desse tópico envolve necessariamente diversas especialidades médicas. Neste artigo, enfatizaremos a maneira pela qual o Grupo de Arritmia do InCor - HC-FMUSP analisa e interage com pacientes sob risco de morrer subitamente, e mais aqueles recuperados de episódio de morte súbita.

Morte súbita na atividade físico-esportiva / Sudden death related to physical activity

Para que seja relacionada com a atividade física, a morte súbita deve ocorrer durante ou até 24 horas depois do exercício, sendo o intervalo mais aceito o de seis horas e mais frequente o de duas horas, independentemente de sua causa etiológica. A frequência das principais causas é apresentada e separada por faixa etária antes e depois dos 35 anos (onde a principal etiologia é a aterosclerose coronária). O possível mecanismo desencadeante é uma arritmia terminal. Na essência, as causas säo as mesmas dos näo-atlelas e a prevençäo deve ser feita por meio de exame pré-participaçäo que inclua história e exame físico, perfil lipídico, radiografia de tórax, eletrocardiograma, teste ergométrico, Doppler-ecocardiograma.