Cardiomyopathy induced by artificial cardiac pacing: myth or reality sustained by evidence?

Implantable cardiac pacing systems are a safe and effective treatment for symptomatic irreversible bradycardia. Under the proper indications, cardiac pacing might bring significant clinical benefit. Evidences from literature state that the action of the artificial pacing system, mainly when the ventricular lead is located at the apex of the right ventricle, produces negative effects to cardiac structure (remodeling, dilatation) and function (dissinchrony). Patients with previously compromised left ventricular function would benefit the least with conventional right ventricle apical pacing, and are exposed to the risk of developing higher incidence of morbidity and mortality for heart failure. However, after almost 6 decades of cardiac pacing, just a reduced portion of patients in general would develop these alterations. In this context, there are not completely clear some issues related to cardiac pacing and the development of this cardiomyopathy. Causality relationships among QRS widening with a left bundle branch block morphology, contractility alterations within the left ventricle, and certain substrates or clinical (previous systolic dysfunction, structural heart disease, time from implant) or electrical conditions (QRS duration, percentage of ventricular stimulation) are still subjects of debate. This review analyses contemporary data regarding this new entity, and discusses alternatives of how to use cardiac pacing in this context, emphasizing cardiac resynchronization therapy.

Predictors of stroke in patients undergoing cardiac surgery.

OBJECTIVE: To determine the risk factors related to the development of stroke in patients undergoing cardiac surgery. METHODS: A historical cohort study. We included 4626 patients aged > 18 years who underwent coronary artery bypass surgery, heart valve replacement surgery alone or heart valve surgery combined with coronary artery bypass grafting between January 1996 and December 2011. The relationship between risk predictors and stroke was assessed by logistic regression model with a significance level of 0.05. RESULTS: The incidence of stroke was 3% in the overall sample. After logistic regression, the following risk predictors for stroke were found: age 50-65 years (OR=2.11 - 95% CI 1.05-4.23 - P=0.036) and age >66 years (OR=3.22 - 95% CI 1.6-6.47 - P=0.001), urgent and emergency surgery (OR=2.03 - 95% CI 1.20-3.45 - P=0.008), aortic valve disease (OR=2.32 - 95% CI 1.18-4.56 - P=0.014), history of atrial fibrillation (OR=1.88 - 95% CI 1.05-3.34 - P=0.032), peripheral artery disease (OR=1.81 - 95% CI 1.13-2.92 - P=0.014), history of cerebrovascular disease (OR=3.42 - 95% CI 2.19-5.35 - P<0.001) and cardiopulmonary bypass time > 110 minutes (OR=1.71 - 95% CI 1.16-2.53 - P=0.007). Mortality was 31.9% in the stroke group and 8.5% in the control group (OR=5.06 - 95% CI 3.5-7.33 - P<0.001). CONCLUSION: The study identified the following risk predictors for stroke after cardiac surgery: age, urgent and emergency surgery, aortic valve disease, history of atrial fibrillation, peripheral artery disease, history of cerebrovascular disease and cardiopulmonary bypass time > 110 minutes.

Unstable angina does not increase mortality in coronary artery bypass graft surgery.

INTRODUCTION: Coronary artery bypass graft is often the treatment of choice for patients who suffer from unstable angina. We do not know whether this condition adds morbidity in this scenario. OBJECTIVE: To compare the outcomes of patients undergoing coronary artery bypass graft with unstable angina framework with patients who underwent coronary artery bypass graft showed no unstable angina. METHODS: Retrospective cohort study. Unstable angina was defined as acute coronary syndrome without ST elevation and without enzymatic alteration and/or class IV angina. RESULTS: Between February 1996 and July 2010, to 2,818 isolated coronary artery bypass graft performed, 1,016 (36.1%) patients had unstable angina. Multivariate analysis showed that patients with preoperative unstable angina used more medications such as acetylsalicylic acid, beta-blocker, heparin (anticoagulation), nitrate and less need for diuretics than patients without unstable angina. Patients with unstable angina used increased monitoring with Swan-Ganz and support with intra-aortic balloon than stable patients. On outcomes, required longer hospitalization (P=0.030) and had a lower death rate (P=0.018) in the post-coronary artery bypass graft alone. CONCLUSION: Submit patients to coronary artery bypass graft in the presence of acute coronary syndrome such as unstable angina did not increase the mortality rate.

The impact of blood transfusion on morbidity and mortality after cardiac surgery.

OBJECTIVES: To analyze the impact of blood transfusion on the incidence of clinical outcomes postoperatively (PO) from cardiac surgery. METHODS: Retrospective cohort study. We analyzed 4028 patients undergoing coronary artery bypass grafting (CABG), valve (TV), or both, in Brazilian tertiary university hospital between 1996 and 2009. We compared the postoperative complications between patients with blood transfusion (n = 916) and non-blood transfusion (n = 3112). Univariate analysis was performed using the Student t test, and multivariate logistic regression bivariate (stepwise forward). Were considered significant variables with P <0.05. RESULTS: Patients who received blood transfusions had more infectious episodes as mediastinitis (4.9% vs. 2.2%, P <0.001), respiratory infection (27.8% vs 17.1%, P <0.001) and sepsis (6.2% vs. 2.5%, P <0.001). There were more episodes of atrial fibrillation (AF) (27% vs. 20.4%, P <0.001), acute renal failure (ARF) (14.5% vs 7.3%, P <0.001) and stroke (4.8% vs. 2.6%, P = 0.001). The length of PO hospital stay was higher in transfused (13 ± 12.07 days vs. 9.72 ± 7.66 days, P <0.001). However, mortality didn't differ between groups (10.9% vs. 9.1%, P = 0.112). The transfusion was shown to be a risk factor for: respiratory infection (OR: 1.91, 95% CI 1.59-2.29, P <0.001), AF (OR: 1.35, 95% CI 1.13-1.61, P = 0.01), sepsis (OR: 2.08, 95% CI 1.4-3.07, P <0.001), mediastinitis (OR: 2.14, 95% CI: 1.43-3.21, P <0.001), stroke (OR: 1.63, 95% CI 1.1-2.41, P = 0.014) and ARF (OR 1.8, 95% CI: 1.39-2.33, P <0.001). CONCLUSION: The blood transfusion is associated with increased risk of infectious events, episodes of AF, ARF and stroke, as well as the increased length of hospital stay but not mortality.

The use of inhibitors of angiotensin-converting enzyme and its relation to events in the postoperative period of CABG.

BACKGROUND: Angiotensin-converting enzyme (ACE) inhibitors reduce the chance of death, myocardial infarction (MI) and cerebrovascular accident (CVA) in patients with coronary disease. However there is no consensus as to its indication in patients undergoing coronary artery bypass grafting (CABG). OBJECTIVE: To assess the relationship between preoperative use of ACE inhibitors and clinical outcomes after CABG. METHODS: Retrospective cohort study. We included data from 3,139 consecutive patients undergoing isolated CABG in Brazilian tertiary care hospital between January 1996 and December 2009. Follow-up was until discharge or death. Clinical outcomes after surgery were analyzed between users and nonusers of ACE inhibitors preoperatively. RESULTS: Fifty-two percent (n=1,635) of patients received ACE inhibitors preoperatively. The use of ACE inhibitors was an independent predictor of need for inotropic support (OR 1.24, 95% CI 1.01 to 1.47, P = 0.01), acute renal failure (OR 1.23, 95% CI 1.01 to 1.73, P = 0.04) and progression to atrial fibrillation (OR 1.32, 95% CI 1.02 to 1.7, P = 0.03) postoperatively. The mortality rate among patients receiving or not preoperative ACE inhibitors was similar (10.3% vs. 9.4%, P = 0.436), as well as the incidence of myocardial infarction and stroke (15.6% vs. 15.0%, P = 0.694 and 3.4% vs. 3.5%, P = 0.963, respectively). CONCLUSION: The use of preoperative ACE inhibitors was associated with increased need for inotropic support and higher incidence of acute renal failure and postoperative atrial fibrillation, not associated with increased rates of myocardial infarction, stroke or death.

Atrioventricular block in the postoperative period of heart valve surgery: incidence, risk factors and hospital evolution.

INTRODUCTION: Disturbances of the cardiac conduction system are potential complications after cardiac valve surgery. OBJECTIVES: This study was designed to investigate the association between perioperative factors and atrio-ventricular block, the need for temporary cardiac artificial pacing and, if necessary, permanent pacemaker implantation after cardiac valve surgery. METHODS: Retrospective analysis of the Cardiac Surgery Database - Hospital São Lucas/PUCRS. The data are collected prospectively and analyzed retrospectively. RESULTS: Between January 1996 and December 2008 were included 1102 valve surgical procedures: 718 aortic valves (65.2%), 407 (36.9%) mitral valve and 190 (17.2%) coronar artery bypass grafting combined with valve repair and 23 (2.1%) aortic and mitral combined surgery. 187 patients (17%) showed clinical and electrocardiographic pattern of atrio-ventricular block requiring artificial temporary pacing. Of these, 14 patients (7.5%) required permanent pacemaker implantation (1.27% of the total valve surgery patients). Multivariate analysis showed association of the incidence of atrio-ventricular block and temporary pacing with mitral valve surgery (OR 1,76; CI 95% 1.08-2.37; P = 0.002), implantation of bioprosthetic devices (OR 1.59; CI 95% 1.02-3.91; P = 0,039), age over 60 years (OR 1.99; CI 95% 1.352.85; P < 0.001), prior use of anti-arrhythmic drugs (OR 1.86; CI 95% 1.04-3.14; P = 0.026) and previous use of b-blocker (OR 1.76; CI 95% 1.25-2.54; P = 0.002). Remarkably the presence of atrio-ventricular block did not significantly show association with increased mortality, but significantly prolonged (P < 0.0001) hospital length-of-stay and, therefore, hospital costs. CONCLUSIONS: Our study presents a group of predictive factors referring to a specific patient profile by which high risk of atrio-ventricular block and the need of temporary cardiac pacing after cardiac valve surgery it is determined.

Dissecção de aorta: diagnóstico diferencial e manejo / Aortic dissection: differential diagnosis and management

A dissecção de aorta é a patologia de maior mortalidade entre as síndromes aórticas agudas com início súbito de dor torácica, sendo 1% por hora, nas primeiras 48 horas e 75% ao final da segunda semana. Menos de 10 % dos pacientes não tratados sobrevivem por um ano1. Por isso, é necessário conhecer a fisiopatologia, a classificação, a apresentação clínica e o diagnóstico diferencial desta patologia, para que o diagnóstico seja evidente, garantindo, assim, o manejo adequado e o melhor desfecho do quadro clínico. O objetivo deste artigo de revisão é fornecer uma estratégia diagnóstica e terapêutica organizada ao clínico, direcionando o conhecimento médico para as manifestações clínicas e para abordagem terapeutica inicial com rapidez, qualidade e eficiência no pronto atendimento.

Aortic dissection is the pathology of higher mortality among the acute aortic syndromes of sudden onset of chest pain, being 1% per hour in the first 48 hours and 75% at the end of the second week. Less than 10% of untreated patients survive for one year. So it is necessary to know the pathophysiology, classification, clinical presentation and differential diagnosis of this disease, so the diagnosis is evident, thus ensuring proper management and the best outcome of the clinical condition. Therefore, the aim of this review article is to provide a diagnostic and therapeutic strategy organized to the professional, directing the medical knowledge to the clinical manifestations and initial therapeutic approach with speed, quality and efficiency of care in the emergency room.

Doença Arterial Periférica (DAP): abordagem inicial / Peripheral Artery Disease (PAD): initial approach

Doenças crônicas acentuadas por um inadequado estilo de vida, como a DAP, ganham espaço nos atendimentos primários com o aumento da expectativa de vida e o envelhecimento da população. Este artigo de revisão visa à abordagem inicial, no diagnóstico, na conduta e em um possível encaminhamento para centros especializados.

Chronic diseases marked by inadequate lifestyle, such as DAP, earns space in primary care with the increasing of life expectancy and the aging of population. This review article aims the initial approach, diagnosis, conduct and a possible referral to specialized centers.

[Proposed preoperative risk score for patients candidate to cardiac valve surgery]. / Proposta de escore de risco pré-operatório para pacientes candidatos à cirurgia cardíaca valvar.

BACKGROUND: To establish a risk score for heart surgery allows the assessment of preoperative risk, informing the patient and defining care during the intervention. OBJECTIVE: To assess preoperative risk factors for death in cardiac valve surgery and construct a simple risk model (score) for in-hospital mortality of patients candidate to surgery at Hospital São Lucas of Pontifícia Universidade Católica do Rio Grande do Sul (HSL-PUCRS). METHODS: The study sample included 1,086 adult patients that underwent cardiac valve surgery between January 1996 and December 2007 at HSL-PUCRS. Logistic regression was used to identify risk and in-hospital mortality factors. The model was developed in 699 patients and its performance was tested in the remaining data (n = 387). The final model was created using the total study sample (n = 1,086). RESULTS: Global mortality was 11.8%: 8.8% of elective cases and 63.8% of emergency cases. At the multivariate analysis, 9 variables remained independent predictors for the outcome: advanced age, surgical priority, female sex, ejection fraction < 45%, concomitant myocardial revascularization (CABG), pulmonary hypertension, NYHA functional class III or IV, creatinine levels (1.5 to 2.49 mg/dl and > 2.5 mg/dl or undergoing dialysis). The area under the ROC curve was 0.83 (95% CI: 0.78-0.86). The risk model showed good capacity for observed/predicted mortality: the Hosmer-Lemeshow test was x(2) = 5.61; p = 0.691 and r = 0.98 (Pearson's coefficient). CONCLUSION: The variables predictive of in-hospital mortality allowed the construction of a simplified risk score for daily practice, which classifies the patient as having low, moderate, high, very high and extremely high preoperative risk.

A score proposal to evaluate surgical risk in patients submitted to myocardial revascularization surgery.

INTRODUCTION: Scores to predict surgical risk in patients submitted to myocardial revascularization surgery are broadly used. OBJECTIVE: To develop a score capable to predict mortality in patients submitted to myocardial revascularization surgery. METHODS: From January 1996 to December 2007, data were collected from 2809 patients submitted to myocardial revascularization surgery at PUC-RS São Lucas Hospital. In 2/3 of the sample (n = 1875), the score was developed, after uni and mutivariated analyses. In the remaining 1/3 (n = 934) the score was validated. The final score was developed with the total sample, using the same variables (n = 2809). The accuracy of the model was tested using the area under the ROC curve. RESULTS: The mean age was 61.3 ± 10.1 years and 34% were women. The risk factors identified as independent predictors of surgical mortality and used for score development (parentheses) were: age > 60 years (2), female (2), extracardiac vasculopathy (2), heart failure functional class III and IV (3), ejection fraction<45% (2), atrial fibrillation (2), chronic obstructive pulmonary disease (3), aortic stenosis (3), creatinine 1.5-2.4 (2), creatinine > 2.5 or dialysis (4), emergency/urgency surgery (16). The area obtained under the ROC curve was 0.86 (CI 0.81-0.9). CONCLUSION: The score developed, using clinical variables easy to obtain (age, sex, extracardiac vasculopathy, functional class, ejection fraction, atrial fibrillation, chronic obstructive pulmonary disease, aortic stenosis, creatinine and emergency/urgency surgery) showed capability to predict mortality in patients submitted to myocardial revascularization surgery in our Hospital.

Risk score elaboration for mediastinitis after coronary artery bypass grafting.

INTRODUCTION: The mediastinitis is a serious postoperative complication of cardiac surgery, with an incidence of 0.4 to 5% and mortality between 14 and 47%. Several models were proposed to assess risk of mediastinitis after cardiac surgery. However, most of these models do not evaluate the postoperative morbidity. OBJECTIVE: This study aims to develop a score risk model to predict the risk of mediastinitis for patients undergoing coronary artery bypass grafting. METHODS: The study sample included data from 2,809 adult patients undergoing coronary artery bypass grafting between January 1996 and December 2007 at Hospital São Lucas -PUCRS. Logistic regression was used to examine the relationship between risk factors and the development of mediastinitis. Data from 1,889 patients were used to develop the model and its performance was evaluated in the remaining data (n=920). The definitive model was created with the data analysis of 2,809 patients. RESULTS: The rate of mediastinitis was 3.3%, with mortality of 26.6%. In the multivariate analysis, five variables remained independent predictors of the outcome: chronic obstructive pulmonary disease, obesity, surgical reintervention, blood transfusion and stable angina class IV or unstable. The area under the ROC curve was 0.72 (95% CI, 0.67-0.78) and P = 0.61. CONCLUSION: The risk score was constructed for use in daily practice to calculate the rate of mediastinitis after coronary artery bypass grafting. The score includes routinely collected variables and is simple to use.

Cardiomyopathy induced by artificial cardiac pacing: myth or reality sustained by evidence? / Miocardiopatia dilatada induzida por estimulação cardíaca artificial: mito ou realidade sustentada pelas evidências?

Implantable cardiac pacing systems are a safe and effective treatment for symptomatic irreversible bradycardia. Under the proper indications, cardiac pacing might bring significant clinical benefit. Evidences from literature state that the action of the artificial pacing system, mainly when the ventricular lead is located at the apex of the right ventricle, produces negative effects to cardiac structure (remodeling, dilatation) and function (dissinchrony). Patients with previously compromised left ventricular function would benefit the least with conventional right ventricle apical pacing, and are exposed to the risk of developing higher incidence of morbidity and mortality for heart failure. However, after almost 6 decades of cardiac pacing, just a reduced portion of patients in general would develop these alterations. In this context, there are not completely clear some issues related to cardiac pacing and the development of this cardiomyopathy. Causality relationships among QRS widening with a left bundle branch block morphology, contractility alterations within the left ventricle, and certain substrates or clinical (previous systolic dysfunction, structural heart disease, time from implant) or electrical conditions (QRS duration, percentage of ventricular stimulation) are still subjecte of debate. This review analyses contemporary data regarding this new entity, and discusses alternatives of how to use cardiac pacing in this context, emphasizing cardiac resynchronization therapy.

A estimulação cardíaca artificial (ECA) é o tratamento mais seguro e eficaz para a bradicardia sintomática irreversível. Nas indicações propícias, pode trazer grande benefício clínico. Contudo, as evidências mostram que a ação da ECA geraria, em alguns casos, efeitos deletérios à estrutura e fisiologia cardíacas. Este potencial efeito negativo da ECA convencional poderia ser mais acentuado principalmente em pacientes com comprometimento prévio da função ventricular esquerda e, sobretudo, quando o eletrodo é colocado em posição apical do ventrículo direito (VD). Intrigante é, contudo, que após quase 6 décadas de ECA do VD, apenas uma reduzida parcela de pacientes apresenta esta condição clinicamente manifesta. Os determinantes do surgimento ou não da cardiopatia por ECA não estão totalmente esclarecidos. Ainda é motivo de debate a existência de uma relação de causalidade entre o padrão de BRE artificial secundário à ativação antifisiológica ventricular, alterações da dinâmica contrátil ventricular, e condições clínicas (disfunção sistólica prévia, cardiopatia estrutural preexistente, tempo desde o implante) ou elétricas (duração do intervalo QRS, dose percentual de estimulação ventricular). Esta revisão aborda dados contemporâneos sobre esta nova entidade e discute alternativas de como utilizar a ECA neste contexto, com ênfase na terapia de ressincronização cardíaca.

Predictors of stroke in patients undergoing cardiac surgery / Preditores de acidente vascular cerebral em pacientes submetidos à cirurgia cardíaca

Objective: To determine the risk factors related to the development of stroke in patients undergoing cardiac surgery. Methods: A historical cohort study. We included 4626 patients aged > 18 years who underwent coronary artery bypass surgery, heart valve replacement surgery alone or heart valve surgery combined with coronary artery bypass grafting between January 1996 and December 2011. The relationship between risk predictors and stroke was assessed by logistic regression model with a significance level of 0.05. Results: The incidence of stroke was 3% in the overall sample. After logistic regression, the following risk predictors for stroke were found: age 50-65 years (OR=2.11 - 95% CI 1.05-4.23 - P=0.036) and age >66 years (OR=3.22 - 95% CI 1.6-6.47 - P=0.001), urgent and emergency surgery (OR=2.03 - 95% CI 1.20-3.45 - P=0.008), aortic valve disease (OR=2.32 - 95% CI 1.18-4.56 - P=0.014), history of atrial fibrillation (OR=1.88 - 95% CI 1.05-3.34 - P=0.032), peripheral artery disease (OR=1.81 - 95% CI 1.13-2.92 - P=0.014), history of cerebrovascular disease (OR=3.42 - 95% CI 2.19-5.35 - P<0.001) and cardiopulmonary bypass time > 110 minutes (OR=1.71 - 95% CI 1.16-2.53 - P=0.007). Mortality was 31.9% in the stroke group and 8.5% in the control group (OR=5.06 - 95% CI 3.5-7.33 - P<0.001). Conclusion: The study identified the following risk predictors for stroke after cardiac surgery: age, urgent and emergency surgery, aortic valve disease, history of atrial fibrillation, peripheral artery disease, history of cerebrovascular disease and cardiopulmonary bypass time > 110 minutes. .

OBJETIVOS: Determinar os preditores de risco relacionados ao desenvolvimento de acidente vascular cerebral em pacientes que realizaram cirurgia cardíaca. Métodos: Estudo de coorte histórico. Incluímos 4626 pacientes com idade > 18 anos submetidos à cirurgia de revascularização do miocárdio, cirurgia cardíaca valvar isolada ou cirurgia valvar associada com revascularização do miocárdio, de janeiro de 1996 e dezembro de 2011. A relação entre os preditores de risco e o acidente vascular cerebral foi avaliada por modelo de regressão logística com nível de significância de 0,05. Resultados: A incidência de acidente vascular cerebral foi 3% na amostra total. A análise multivariada identificou como preditores de risco para o acidente vascular cerebral: idade 50-65 anos (OR=2,11 - 95% IC 1,05-4,23 - P=0,036) e idade > 66 anos (OR=3,22 - 95% IC 1,6-6,47 - P=0,001), cirurgia de urgência/emergência (OR=2,03 - 95% IC 1,20-3,45 - P=0,008), valvulopatia aórtica (OR=2,32 - 95% IC 1,18-4,56 - P=0,014), fibrilação atrial (OR=1,88 - 95% IC 1,05-3,34 - P=0,032), doença arterial obstrutiva periférica (OR=1,81 - 95% IC 1,13-2,92 - P=0,014), história de doença cerebrovascular (OR=3,42 - 95% IC 2,19-5,35 - P<0,001) e tempo de circulação extracorpórea >110 minutos (OR=1,71 - 95% IC 1,16-2,53 - P=0,007). A mortalidade foi 31,9% nos pacientes que sofreram AVC e 8,5% nos sem AVC (OR=5,06 - 95% IC 3,5-7,33 - P<0,001). Conclusão: Idade, cirurgia de urgência/emergência, doença de valva aórtica, história de fibrilação atrial, doença arterial obstrutiva periférica, história de doença cerebrovascular e tempo de circulação extracorpórea > 110 minutos foram preditores independentes para o desenvolvimento de AVC i...

Angina instável não aumenta mortalidade em cirurgia de revascularização miocárdica / Unstable angina does not increase mortality in coronary artery bypass graft surgery

INTRODUÇÃO: A cirurgia de revascularização do miocárdio muitas vezes é o tratamento de escolha de pacientes que sofrem angina instável. Não sabemos se essa condição acresce morbimortalidade nesse cenário. OBJETIVO: Comparar os desfechos dos pacientes submetidos a cirurgia de revascularização do miocárdio com quadro de angina instável com os pacientes submetidos a cirurgia de revascularização do miocárdio que não apresentaram angina instável. MÉTODOS: Coorte retrospectiva. A angina instável foi definida como síndrome coronariana aguda sem supradesnivelamento de ST e sem alteração enzimática e/ou angina classe IV. RESULTADOS: No período entre fevereiro de 1996 a julho de 2010, de 2.818 a cirurgia de revascularização do miocárdio isoladas realizadas, 1.016 (36,1%) pacientes apresentaram angina instável. A análise multivariada demonstrou que os pacientes com angina instável no pré-operatório utilizaram mais medicações como ácido acetilsalicílico, betabloqueador, heparina (anticoagulação plena), nitrato e menor necessidade de diureticoterapia, do que pacientes sem angina instável. Pacientes com angina instável utilizaram maior monitorização com Swan-Ganz e suporte com balão intra-aórtico do que os pacientes estáveis. Sobre os desfechos, necessitaram de maior tempo de internação (P=0,030) e apresentaram menor taxa de óbito (P=0,018) no pós-operatório de cirurgia de revascularização do miocárdio isolada. CONCLUSÃO: Submeter pacientes a cirurgia de revascularização do miocárdio isolada na vigência de síndrome coronariana aguda como angina instável não elevou a taxa de mortalidade.

INTRODUCTION: Coronary artery bypass graft is often the treatment of choice for patients who suffer from unstable angina. We do not know whether this condition adds morbidity in this scenario. OBJECTIVE: To compare the outcomes of patients undergoing coronary artery bypass graft with unstable angina framework with patients who underwent coronary artery bypass graft showed no unstable angina. METHODS: Retrospective cohort study. Unstable angina was defined as acute coronary syndrome without ST elevation and without enzymatic alteration and/or class IV angina. RESULTS: Between February 1996 and July 2010, to 2,818 isolated coronary artery bypass graft performed, 1,016 (36.1%) patients had unstable angina. Multivariate analysis showed that patients with preoperative unstable angina used more medications such as acetylsalicylic acid, beta-blocker, heparin (anticoagulation), nitrate and less need for diuretics than patients without unstable angina. Patients with unstable angina used increased monitoring with Swan-Ganz and support with intra-aortic balloon than stable patients. On outcomes, required longer hospitalization (P=0.030) and had a lower death rate (P=0.018) in the post-coronary artery bypass graft alone. CONCLUSION: Submit patients to coronary artery bypass graft in the presence of acute coronary syndrome such as unstable angina did not increase the mortality rate.

Avaliação da função renal após a terapia de ressincronização cardíaca / Assessment of renal function after cardiac resynchronization therapy

A síncope é um problema médico comum e, se relacionada a distúrbio da condução atrioventricular (AV), pode indicar o implante de marcapasso definitivo. Por isso, a distinção entre o bloqueio AV devido a doença degenerativa e aquele induzido por aumento do tônus vagal tem importante implicação prognóstica e terapêutica. O mecanismo responsável pela síncope vasovagal é a perda abrupta e transitória da consciência decorrente de hipoperfusão cerebral global e transitória, com início rápido, curta duração e recuperação completa e espontânea. É uma causa comum de síncope e tem bom prognóstico. Em sua forma cardioinibitória, costuma ter como mecanismo a bradicardia sinusal ou a assistolia associada a queda da pressão sanguínea, porém podem ocorrer outras apresentações menos comuns, como o bloqueio AV (BAVT, BAV 2:1 BAV avançado). Descreve-se o caso de uma paciente do sexo feminino, com 54 anos, hipertensa, chagásica (megaesôfago) e vários episódios de síncope no último ano. Foi investigada com eletrocardiograma (BAV 1º grau), ecocardiograma (normal), Holter (BAV 2 grau Mobitz I durante o sono), teste ergométrico (resposta cronotrópica e condução AV normais durante o esforço) e tilt test sensibilizado positivo (BAVT) com manutenção de distúrbios da condução atrioventricular (BAVT, BAV avançado) associados a pré-síncope após retorno a zero grau, quadro que durou 25 minutos. Como parte da investigação, foi submetida a estudo eletrofisiológico com intervalo HV normal. Foi indicado marcapasso definitivo, porém a paciente recusou-se. Retornou após um ano com manutenção do quadro de síncope. Foi então submetida a implante de marcapasso definitivo de dupla-câmara e encontra-se há 15 meses sem sintomas.

Abstract: Syncope is a common medical problem and if related to disorder of atrioventricular (AV) conduction may be indicative of permanent pacemaker implantation. Therefore, the distinction between AV block due to degenerative disease and that induced by increased vagal tone has important prognostic and therapeutic implications. The mechanism responsible for vasovagal syncope is a sudden and transient loss of consciousness due to global cerebral hypoperfusion with rapid onset, short duration, and spontaneous complete recovery. It is a common cause of syncope and has a good prognosis. When cardioinhibitory, usually has as a mechanism of syncope sinus bradycardia or asystole associated to drop in blood pressure, but other less common presentations may occur as AV block (AVB, advanced AVB, AVB 2:1). We describe the case of a female patient, 54 years old, with hypertension, Chagas disease (megaesophagus) and several episodes of syncope in the last year. She was investigated by electrocardiogram (1st degree AVB), echocardiogram (normal), holter (Mobitz I 2nd degree AVB during sleep), exercise testing (normal chronotropic response and AV conduction during exercise) and tilt test (complete AVB) with maintenance of atrioventricular block (complete AVB and advanced AVB) associated with pre-syncope after returning to zero degree. This situation last for 25 minutes. As part of the investigation she underwent electrophysiologic study with normal HV interval. Permanent pacemaker was indicated but the patient refused. After 1 year she returned with maintenance of syncope and then underwent implantation of a permanent dual chamber pacemaker. She is without symptoms in the last 15 months.

Insuficiência arterial aguda de membros inferiores / Acute arterial insufficiency of lower limbs

Análise dos mecanismos fisiopatológicos, manifestações clínicas, diagnóstico e tratamento de oclusão arterial aguda.

Analysis of the pathophysiological mechanisms, clinical manifestations, diagnosis and treatment of acute arterial occlusion.

Dor em membros inferiores: patologias venosas / Pain in lower extremities: venous pathologies

Patologias venosas incluem uma ampla variedade de enfermidades que podem apresentar-se desde um quadro assintomático até queixas de dor, edema e ulcerações. Neste trabalho os autores realizaram uma revisão bibliográfica sobre as principais doenças venosas causadoras de dor em membros inferiores: trombose venosa profunda (TVP), tromboflebite e doença venosa crônica.

Venous diseases include a wide variety of illness that may present from asymptomatic cases to complaints of pain, edema, and ulcerations. In this work the authors performed a literature review on the main venous diseases causing pain in the lower extremity: deep vein thrombosis (DVT), thrombophlebitis and chronic venous disease.

High dose of amiodarone in a short-term period reduces the incidence of postoperative atrial fibrillation and atrial flutter.

OBJECTIVE: To investigate whether oral amiodarone administered before surgery for a short period in high dose would reduce the incidence of postoperative atrial fibrillation or atrial flutter and reduces the length of hospital stay. METHODS: In the double-blind, randomized study, 93 patients were given either oral amiodarone (46 patients) or placebo (47 patients). Therapy consisted of 600 mg of amiodarone three times a day, started at minimum 30 hours and at maximum 56 hours before surgery. RESULTS: Postoperative atrial fibrillation or atrial flutter occurred in 8 of 46 patients in the amiodarone group (17.4%) and 19 of the 47 patients in the placebo group (40.4%) (p=0.027). The mean dose of amiodarone was 2.8 g. Patients in the amiodarone group were hospitalized for 8.9+/-3.1 days and patients in the placebo group were hospitalized for 11.4+/-8.7 days (p=0.07). The hospital length were significantly prolonged in patients who developed atrial arrhythmias after surgery, despite the treatment received.(p<0.001). CONCLUSION: This new alternative way of using amiodarone in high dose and in a short-term period before surgery reduce the incidence of postoperative atrial fibrillation or atrial flutter in coronary artery bypass graft surgery.

O uso de inibidores da enzima conversora de angiotensina e sua relação com eventos no pós-operatório de cirurgia de revascularização miocárdica / The use of inhibitors of angiotensin-converting enzyme and its relation to events in the postoperative period of CABG

FUNDAMENTO: Os inibidores da enzima conversora de angiotensina (IECA) reduzem o risco de óbito, infarto agudo do miocárdio (IAM) e acidente vascular encefálico (AVE) em portadores de doença coronariana. No entanto, não há consenso quanto à sua indicação em pacientes que serão submetidos à cirurgia de revascularização miocárdica (CRM). OBJETIVO: Avaliar a relação entre uso pré-operatório de IECA e eventos clínicos após realização da CRM. MÉTODOS: Estudo de coorte retrospectivo. Foram incluídos dados de 3.139 pacientes consecutivos submetidos à CRM isolada em hospital terciário brasileiro, entre janeiro de 1996 e dezembro de 2009. O seguimento dos pacientes foi realizado até a alta hospitalar ou óbito. Desfechos clínicos no pós-operatório foram analisados entre os usuários e os não-usuários de IECA no pré-operatório. RESULTADOS: Cinquenta e dois por cento (1.635) dos pacientes receberam IECA no pré-operatório. O uso de IECA foi preditor independente da necessidade de suporte inotrópico (RC 1,24, IC 1,01-1,47; P=0,01), de insuficiência renal aguda (IRA, RC 1,23, IC 1,01-1,73; P=0,04) e de evolução para fibrilação atrial (FA, RC 1,32, IC 1,02-1,7; P=0,03) no pós-operatório. A mortalidade entre os pacientes que receberam ou não IECA no pré-operatório foi semelhante (10,3 vs. 9,4%, P=0,436), bem como a incidência de IAM e AVE (15,6 vs. 15,0%, P=0,694 e 3,4 vs. 3,5%, P=0,963, respectivamente). CONCLUSÃO: O uso pré-operatório de IECA foi associado a maior necessidade de suporte inotrópico e maior incidência de IRA e FA no pós-operatório, não estando associado ao aumento das taxas de IAM, AVE ou óbito.

BACKGROUND: Angiotensin-converting enzyme (ACE) inhibitors reduce the chance of death, myocardial infarction (MI) and cerebrovascular accident (CVA) in patients with coronary disease. However there is no consensus as to its indication in patients undergoing coronary artery bypass grafting (CABG). OBJECTIVE: To assess the relationship between preoperative use of ACE inhibitors and clinical outcomes after CABG. METHODS: Retrospective cohort study. We included data from 3,139 consecutive patients undergoing isolated CABG in Brazilian tertiary care hospital between January 1996 and December 2009. Follow-up was until discharge or death. Clinical outcomes after surgery were analyzed between users and nonusers of ACE inhibitors preoperatively. RESULTS: Fifty-two percent (n=1,635) of patients received ACE inhibitors preoperatively. The use of ACE inhibitors was an independent predictor of need for inotropic support (OR 1.24, 95% CI 1.01 to 1.47, P = 0.01), acute renal failure (OR 1.23, 95% CI 1.01 to 1.73, P = 0.04) and progression to atrial fibrillation (OR 1.32, 95% CI 1.02 to 1.7, P = 0.03) postoperatively. The mortality rate among patients receiving or not preoperative ACE inhibitors was similar (10.3% vs. 9.4%, P = 0.436), as well as the incidence of myocardial infarction and stroke (15.6% vs. 15.0%, P = 0.694 and 3.4% vs. 3.5%, P = 0.963, respectively). CONCLUSION: The use of preoperative ACE inhibitors was associated with increased need for inotropic support and higher incidence of acute renal failure and postoperative atrial fibrillation, not associated with increased rates of myocardial infarction, stroke or death.