Wide QRS complex tachycardia in patients with Chagas' disease: Sustained ventricular tachycardia until proven otherwise.

Algorithms used for the differential diagnosis of wide QRS complex tachycardia are extremely important in clinical practice, but they have limitations and should be applied with caution. We describe a case of a patient with positive serology for Chagas disease and normal echocardiogram who presented an episode of wide QRS complex tachycardia. It was initially diagnosed as sustained ventricular tachycardia using the Brugada and Vereckei algorithms and it was sent to the reference service for the implant of a cardioverter defibrillator. However, the clinical history, electrocardiogram in sinus rhythm and the electrophysiological study were fundamental to the correct diagnosis and treatment of a posterolateral atrioventricular accessory pathway.

Quando indicar ablação para as principaisarritmias atriais e ventriculares? / When is ablation indicated for the principal atrial and ventricular arrhythmias?

Arritmias supraventriculares são distúrbios do ritmo comuns na prática clínica diária. As duas principais opções de tratamento são o medicamentoso, considerado de segunda linha devido à baixa eficácia, necessidade de uso por longa data, efeitos colaterais, interaçãomedicamentosa e potencial efeito proarrítmico; e o invasivo com ablação, atualmente o padrão ouro devido a baixa complicação e alta eficácia. As arritmias ventriculares são menos comuns, podendo estar associadas a prognóstico e risco de morte súbita cardíacadiferentes, de acordo com a presença ou não de alteração estrutural cardíaca. A ablação por cateter possui papel diferente no tratamento das arritmias ventriculares nestes dois grupos de pacientes. O objetivo desta revisão é avaliar o papel da ablação por cateter,resumindo as principais indicações deste procedimento no manuseio das arritmias supraventriculares e ventriculares...

Supraventricular arrhythmias are common rhythm disturbances in daily clinical practice. The two main treatment options are pharmacological, and catheter ablation. Pharmacologicaltreatment is considered the second line option due to its low efficacy, the need for long-term adherence, the risk of side effects, drug interactions, and potential proarrhythmic effects. Catheter ablation is currently the gold standard therapy, due to its low complications and high efficacy. Ventricular arrhythmias are less common, and may be associated with different prognoses and levels of risk of sudden cardiac death, depending on the presence or absence of structural heart disease. Catheter ablation has a different role in the treatment of ventricular arrhythmias in these two groups of patients. The objective ofthis review is to evaluate the role of catheter ablation, summarizing the main indications of this procedure in the management of supraventricular and ventricular arrhythmia...

Clinical predictors of inducible sustained ventricular tachycardia during electrophysiologic study in patients with chronic Chagas' heart disease.

BACKGROUND: Clinical independent predictors of inducible sustained ventricular tachycardia (VT) during electrophysiologic study (EPS) are not known in patients with chronic Chagas' heart disease. The purpose of this investigation was to fill this gap. METHODS: The medical charts of 47 patients with a positive serology for Chagas' disease who had undergone EPS between September 2006 and July 2012 at our institution were reviewed. Reasons for the EPS were the presence of unexplained syncope, non-sustained ventricular tachycardia (NSVT) on either resting ECG or 24 h-Holter monitoring as well as a LVEF < 55% and > 35% at echocardiography. A stepwise logistic regression analysis was performed to identify noninvasive predictors of inducible sustained VT/ventricular fibrillation during EPS. RESULTS: On univariate analysis, syncopal episodes (p = 0.04), amiodarone therapy (p < 0.005), diastolic blood pressure (p = 0.03), creatinine serum levels (p < 0.001), potassium serum levels (p < 0.001), and lengthening of the QRS complex (p = 0.03) were associated with inducible sustained VT during EPS. In the multivariate model, amiodarone therapy (p = 0.03; hazard ratio = 10; Wald coefficient = 4.5; 95% confidence interval 1.2 to 85.2) was the only variable retained as independent predictor of inducible sustained VT during EPS. CONCLUSION: Amiodarone therapy was the only independent variable associated with sustained VT inducibility during EPS in patients with chronic Chagas' heart disease.

Acute kidney injury after on-pump coronary artery bypass graft surgery.

BACKGROUND: The acute kidney injury (AKI) is a complex disease for which there is no accepted standard definition nowadays. The Acute Kidney Injury Network (AKIN) represents an attempt to standardize the criteria for diagnosis and staging of acute renal dysfunction based on recently published RIFLE criteria, that means, (Risk, Injury, Failure, Loss, and End-stage kidney disease). OBJECTIVES: To evaluate the incidence and associated mortality of AKI in patients submitted to on-pump coronary artery bypass graft surgery (on-pump CABG). METHODS: A total of 817 patients were divided into two groups: negative AKI (-), with 421 patients (51.5%), and positive AKI (+), with 396 patients (48.5%). Increase of 0.3 mg/dL in creatinine or of 50% in creatinine's basal value was considered as AKI. RESULTS: The rate of patient's mortality with or without AKI within 30 days after cardiac surgery was 12.6% and 1.4%, respectively (p<0.0001). In a multivariate logistic regression model, AKI after on-pump CABG was an independent predictor of death within 30 days (OR=6.7; p=0.0002). This group of patients presented a longer period of permanency in intensive care unit (ICU) [median 2 days (2 to 3) versus 3 days (2 to 5); p=0.0001] and a bigger proportion of patients with prolonged permanence in intensive care (>14 days) (14 versus 2%; p=0.0001). CONCLUSION: In the studied population, even a discrete alteration in renal function, based on AKIN criteria, was an independent predictor of death in 30 days after on-pump CABG.

Central venous pressure in femoral catheter: correlation with superior approach after heart surgery.

OBJECTIVE: It is common to obtain femoral venous approach in patients undergoing combined heart surgery or as an alternative to superior approach (internal jugular vein or subclavian vein). The aim of this study was to compare the measures of central venous pressure (CVP) at two different sites (superior versus femoral). METHODS: We prospectively and openly allocated 60 patients who underwent heart surgery between July from November 2006. Three measures were obtained from each patient at each site (admission, 6 and 12 hours after surgery) in two different inclinations of the headboard (zero and 30 degrees) totaling 720 measures. RESULTS: Fifty five percent of patients who underwent coronary artery bypass grafting, 38% heart valve surgery and 7% other surgeries. The mean of CVP +/- standard deviation (SD) measured in superior approach was 13.0 +/- 5.5 mmHg (zero degree) and 13.3 +/- 6.1 mmHg (30 degrees) while the measures in inferior approach were 11.1 +/- 4.9 mmHg (zero degree) and 13.7 +/- 4.6 mmHg (30 degrees). The linear correlation (r) between the measures in both sites was 0.66 (zero degree) and 0.53 (30 degrees), both with p value<0.0001. CONCLUSION: The CVP can be measured with accuracy in the femoral venous approach in the immediate postoperative period of heart surgery with better linear correlation obtained with the measures made with the headboard positioned at zero degree.

Síndrome do QT longo congênito associado a bloqueio atrioventricular 2: 1 em lactente com síncope de repetição tratado como epilepsia / Congenital long QT syndrome associated with 2: 1 atrioventricular block in infant with repeated syncope treated as epilepsy

A Síndrome do QT longo (SQTL) congênito é uma doença dos canais iônicos cardíacos que está associada com síncope, taquiarritmias ventriculares e morte súbita cardíaca em pacientes com coração normal. Raramente, apresenta-se com Bloqueio Atrioventricular 2:1, apresentando mortalidade maior que 50% nos primeiros seis meses de vida, mesmo com tratamento adequado. O caso aqui descrito relata a evolução clínico de lactente com 6 meses de idade com SQTL congênito, síncope de repetição e BAV 2:1 inicialmente tratado como epilepsia, que após tratamento clínico adequado com mudança de estilo de vida, betabloqueadores e implante de marcapasso, não apresentou mais eventos cardíacos. No seguimento tardio (com 6 anos de vida), foi implantado Cardiodesfibrilador Implantável, sem terapias até a presente data.

Congenital long QT syndrome is a disease of cardiac ion channels that is associated withs yncope, cardiac sudden death and ventricular tachyarrhythmias in patients with normal hearts. Rarely,it presents associated with 2:1 atrioventricular block; in this case the mortality rate is higher than 50% in the first six months of life even with adequate treatment. The case described here reports on the clinical evolution of a six-month-old infant with congenital long QT syndrome, syncope of repetition and 2:1 atrioventricular block initially treated as epilepsy, that after the correct clinical treatment with changes in lifestyle, beta-blockers and pacemaker implantation, did not have further cardiac events. In the long term follow-up (six years of life), a defibrillator was implanted without the need of further therapies todate.

Lesão renal aguda após revascularização do miocárdio com circulação extracorpórea / Lesión renal aguda post-revascularización del miocardio con circulación extracorpórea / Acute kidney injury after on-pump coronary artery bypass graft surgery

FUNDAMENTO: A lesão renal aguda (LRA) é uma doença complexa para a qual, atualmente, não há uma definição padrão aceita. A AKIN (Acute Kidney Injury Network) representa uma tentativa de padronização dos critérios para diagnóstico e estadiamento da LRA, baseando-se nos critérios RIFLE (risk, injury, failure, loss, e end-stage kidney disease), publicados recentemente. OBJETIVOS: Avaliar a incidência e mortalidade associada à LRA em pacientes submetidos à revascularização do miocárdio (RM) com circulação extracorpórea (CEC). MÉTODOS: O total de 817 pacientes foi dividido em dois grupos: LRA negativa (-), com 421 pacientes (51,5 por cento), e LRA positiva (+), com 396 pacientes (48,5 por cento). Foi considerado LRA a elevação da creatinina em 0,3 mg/dl ou aumento em 50 por cento da creatinina em relação a seu valor basal. RESULTADOS: A mortalidade em 30 dias dos pacientes com e sem LRA foi de 12,6 por cento e 1,4 por cento, respectivamente (p < 0,0001). Em um modelo de regressão logística multivariada, LRA após RM com CEC foi preditora independente de óbito em 30 dias (OR 6,7 - p = 0,0002). Esse grupo de pacientes teve maior tempo de permanência em UTI [mediana 2 dias (2 a 3) vs. 3 dias (2 a 5) - p < 0,0001)] e uma maior proporção de pacientes com permanência prolongada na terapia intensiva (> 14 dias) - 14 por cento vs. 2 por cento; p < 0,0001. CONCLUSÃO: Na população estudada, mesmo uma discreta alteração da função renal baseada nos critérios do "Acute Kidney Injury Network - AKIN" foi preditora independente de óbito em 30 dias após RM com CEC.

BACKGROUND: The acute kidney injury (AKI) is a complex disease for which there is no accepted standard definition nowadays. The Acute Kidney Injury Network (AKIN) represents an attempt to standardize the criteria for diagnosis and staging of acute renal dysfunction based on recently published RIFLE criteria, that means, (Risk, Injury, Failure, Loss, and End-stage kidney disease). OBJECTIVES: To evaluate the incidence and associated mortality of AKI in patients submitted to on-pump coronary artery bypass graft surgery (on-pump CABG). METHODS: A total of 817 patients were divided into two groups: negative AKI (-), with 421 patients (51.5 percent), and positive AKI (+), with 396 patients (48.5 percent). Increase of 0.3 mg/dL in creatinine or of 50 percent in creatinine's basal value was considered as AKI. RESULTS: The rate of patient's mortality with or without AKI within 30 days after cardiac surgery was 12.6 percent and 1.4 percent, respectively (p<0.0001). In a multivariate logistic regression model, AKI after on-pump CABG was an independent predictor of death within 30 days (OR=6.7; p=0.0002). This group of patients presented a longer period of permanency in intensive care unit (ICU) [median 2 days (2 to 3) versus 3 days (2 to 5); p=0.0001] and a bigger proportion of patients with prolonged permanence in intensive care (>14 days) (14 versus 2 percent; p=0.0001). CONCLUSION: In the studied population, even a discrete alteration in renal function, based on AKIN criteria, was an independent predictor of death in 30 days after on-pump CABG.

FUNDAMENTO: Lesión renal aguda (LRA) es una compleja enfermedad, la que, actualmente, no tiene definición patrón acepta. AKIN (Acute Kidney Injury Network) representa una tentativa de estandardización de criterios para el diagnostico y estadiamiento de LRA basado en los criterios RIFLE (risk, injury, failure, loss, y end-stage kidney disease) publicados recientemente. OBJETIVO: Evaluar la incidencia y mortalidad asociada a LRA en pacientes sometidos a revascularización del miocardio (RM) con circulación extracorpórea (CEC). MÉTODOS: El total de 817 pacientes fueron divididos en dos grupos: LRA negativa (-), con 421 pacientes (51,5 por ciento), y LRA positiva (+), con 396 pacientes (48,5 por ciento). LRA fue considerada la elevación de creatinina en 0,3 mg/dl el aumento en 50 por ciento de creatinina en relación a su valor basal. RESULTADOS: La mortalidad dentro de 30 días de los pacientes con y sin LRA ha sido de 12,3 y 1,4 por ciento, respectivamente (p<0,0001). En un modelo de regresión logística multivariado, LRA tras RM con CEC fue predictora independiente de óbito en 30 días (OR=6,7; p=0,0002). Ese grupo de pacientes tuvo el mayor tiempo de permanencia en unidad de cuidados intensivos (UCI) (6,0±9,5 días versus 3,4±4,0 días; p<0,0001) y una proporción de pacientes con permanencia prolongada en la terapia intensiva (>14 días), 14 versus 2 por ciento; p<0,0001. CONCLUSIÓN: En la población estudiada, mismo una discreta alteración de la función renal basada en los criterios AKIN ha sido predictora independiente de óbito, en 30 días tras RM con CEC.

Drogas anticoagulantes em pacientes com arritmia / Anticoagulants drugs in patients with arrhythmia

O uso de anticoagulantes para profilaxia de tromboembolismo restringe-se à Fibrilaçãom Atrial (FA) e Flutter Atrial (FLA). FA é a arritmia sustentada mais prevalente nos dias de hoje, com aumento da prevalência de acordo com o aumento da idade. Está associada com maior risco de Insuficiência Cardíaca, mortalidade e Acidente Vascular Encefalico (um em cada cinco), sendo este último associado à maior gravidade, incapacidade e mortalidade do que isquemias cerebrais de outra etiologia. Deste fato, vem a importância de um adequado tratamento antitrombótico a fim de se evitar a cardioembolia. Neste artigo, temos por objetivo indicar os principais fatores de risco para tromboembolismo na FA, as drogas indicadas para profilaxia antitrombótica, incluindo os novos anticoagulantes orais, sua principais indicações, benefícios e riscos, inclusive em situações especiais como cardioversão e ablação de FA.

The use of anticoagulants for thromboembolism prophylaxis is restricted to Atrial Fibrillation (AF) and Atrial Flutter (FLA). Atrial fibrillation is the most prevalent sustained arrhythmia nowadays, with an increasing prevalence during the aging process. It is associated with an increased risk of heart failure, mortality and stroke (one in five), which is associated with greater severity, disability and mortality than with any other etiology of cerebral ischemia. This fact justifies of an adequate antithrombotic treatment in order to avoid thromboembolism. In this article, we aim to outline the main risk factors of thromboembolism in AF, drugs indicated for antithrombotic prophylaxis, including new oral anticoagulant, the main indications, risks and benefits, including special situations such as electrical cardioversion and ablation of AF.

Pressão venosa central em cateter femoral: correlação com acesso superior após cirurgia cardíaca / Central venous pressure in femoral catheter: correlation with superior approach after heart surgery

OBJETIVO: É comum a obtenção de acesso venoso femoral em pacientes submetidos a cirurgia cardíaca em associação ou como alternativa ao acesso superior (veia jugular interna ou veia subclávia). O objetivo deste estudo foi comparar as medidas de pressão venosa central (PVC) em dois sítios diferentes (superior vs. femoral). MÉTODOS: Estudo prospectivo e aberto com 60 pacientes submetidos a cirurgia cardíaca no período de julho a novembro de 2006. Foram obtidas três medidas de cada paciente em cada sítio (admissão, 6 e 12 horas após a cirurgia) em duas inclinações diferentes da cabeceira do leito (zero e 30 graus), totalizando 720 medidas. RESULTADOS: Cinqüenta e cinco por cento dos pacientes foram submetidos a revascularização do miocárdio, 38 por cento a cirurgia valvar e 7 por cento a outras cirurgias. A média de PVC ± desvio padrão (DP) medida no acesso superior foi de 13,0 ± 5,5 mmHg (zero grau) e 13,3 ± 6,1 mmHg (30 graus), enquanto que as medidas no acesso inferior foram 11,1 ± 4,9 mmHg (zero grau) e 13,7 ± 4,6 mmHg (30 graus). A correlação linear (r) entre as medidas nos dois sítios foi de 0,66 (zero grau) e 0,53 (30 graus), ambas com p < 0,0001. CONCLUSÃO: A PVC pode ser medida com acurácia no acesso venoso femoral no pós-operatório imediato de cirurgia cardíaca, com melhor correlação linear obtida com as medidas feitas com a cabeceira do leito posicionada em zero grau.

OBJECTIVE: It is common to obtain femoral venous approach in patients undergoing combined heart surgery or as an alternative to superior approach (internal jugular vein or subclavian vein). The aim of this study was to compare the measures of central venous pressure (CVP) at two different sites (superior versus femoral). METHODS: We prospectively and openly allocated 60 patients who underwent heart surgery between July from November 2006. Three measures were obtained from each patient at each site (admission, 6 and 12 hours after surgery) in two different inclinations of the headboard (zero and 30 degrees) totaling 720 measures. RESULTS: Fifty five percent of patients who underwent coronary artery bypass grafting, 38 percent heart valve surgery and 7 percent other surgeries. The mean of CVP ± standard deviation (SD) measured in superior approach was 13.0 ± 5.5 mmHg (zero degree) and 13.3 ± 6.1 mmHg (30 degrees) while the measures in inferior approach were 11.1 ± 4.9 mmHg (zero degree) and 13.7 ± 4.6 mmHg (30 degrees). The linear correlation (r) between the measures in both sites was 0.66 (zero degree) and 0.53 (30 degrees), both with p value<0.0001. CONCLUSION: The CVP can be measured with accuracy in the femoral venous approach in the immediate postoperative period of heart surgery with better linear correlation obtained with the measures made with the headboard positioned at zero degree.

Síndrome do QT longo congênito associado a bloqueio atrioventricular 2: 1 em lactente com síncopes de repetição tratado como epilepsia / Congenital long QT syndrome associated with 2: 1 atrioventricular block in infant with repeated syncope treated

A síndrome do QT longo (SQTL) congênito é uma doença dos canais iônicos cardíacos que está associada com síncope, taquiarritmias ventriculares e morte súbita cardíaca em pacientes com coração normal. Raramente, apresenta-se com boqueio atrioventricular 2:1, apresentando mortalidade maior que 50% nos primeiros 6 meses de vida, mesmo com tratamento adequado. O caso aqui descrito relata a evolução clínico de lactente com 6 meses de idade com SQTL congênito, síncope de repetição e BAV 2:1 inicialmente tratado como eplepsia, que após tratamento clínico adequado com mudança de estilo de vida, betabloqueadores e implante de marca-passo, não apresentou mais eventos cardíacos. No seguimento tardio (com 6 anos de vida), foi implantado cardiodesfibrilador implantável, sem terapias até a presente data.

Narcolepsia: diagnóstico diferencial nas síncopes não explicadas / Narcolepsy: differential diagnostics in the unexplained syncopes

A narcolepsia é uma doença com alta prevalência, frequentemente subdiagnosticada. Suas manifestações mais comuns, a hipersonolência e a cataplexia, muitas vezes podem simular episódios de síncope. Esta revisão tem o objetivo de esclarecer os mecanismos fisiopatológicos dessa patologia, assim como suas manifestações clínicas e seu manejo. Dessa forma, espera-se contribuir para que o médico a reconheça e a diferencie das causas mais frequentes de síncope.