O enxerto de artéria torácica interna tem demonstrado capacidade de remodelamento devido a interação com o leito arterial coronariano. O objetivo deste estudo foi analisar a influência dos fatores clínicos e angiográficos no remodelamento dos enxertos, definido como variação no calibre vascular. Casuística e métodos: No período entre 1983 e 1999, 356 pacientes realizaram cirurgia de revascularização do miocárdio utilizando a artéria torácica interna esquerda para o ramo interventricular anterior e a artéria torácica interna direita para um ramo da circunflexa. Trinta e dois pacientes foram submetidos a cineangiocoronariografia pós-operatória, a qual foi posteriormente analisada com o aplicativo CASS II®. Este estudo observacional apresentou acompanhamento médio de 42 meses(6-204 meses). As variáveis angiográficas analisadas foram os diâmetros proximal e distal dos enxertos arteriais (variável dependente), área coronariana, pontuação de fluxo TIMI, diâmetro de estenose proximal, fluxo dominante distal e ramos patentes. Fatores de risco cardiovascular também foram incluídos. Resultados: O modelo de regressão linear múltiplo demonstrou um R2ajustado=0,69 (p=0,0001) para o modelo a direita e R2ajustado=0,46 (p=0,002) para a esquerda. Os enxertos apresentaram diâmetros proximal e distal de 2,67mm ±0,085 e 2,232mm ±0,085 à esquerda; 2,458mm ±0,088 e 2,010mm ± 0,091 (média±EP) à direita, respectivamente (p>0,05). Nenhuma variável clínica obteve correlação significante estatisticamente. A área coronariana apresentou coeficiente de beta=0,42 (0,14-0,6/IC-95%) e diâmetro de estenose proximal de 0,55 (0,40-0,65/IC-95%) para o remodelamento do lado direito. A área coronariana demonstrou coeficiente de beta=0,54 (0,3- 0,68/IC-95%) para o remodelamento do lado esquerdo. Conclusões: A artéria torácica interna não demonstrou diferença de calibre em relação a lateralidade (esquerda vs direita). O diâmetro de estenose proximal da artéria coronária revascularizada demonstrou correlação positiva com o remodelamento dos enxertos do lado direito. A área da artéria coronária revascularizada foi a única variável de influência para o remodelamento bilateral dos enxertos / Internal thoracic artery grafts has demonstrated capacity for remodeling due to interaction with the coronary artery bed. The goal was to analysis the influence of clinical and angiographic factors in this remodeling as defined as grafts caliber variation. Methods: In a period from 1983 to 1999, 356 patients underwent to coronary artery bypass surgery using the left internal thoracic artery anastomosed to interventricular anterior branch and the right internal thoracic artery to circumflex branches. Thirty two patients were submitted to postoperative coronary angiography which was further analysed by CASS II® software. The mean follow-up of this observational study was 42 months(6- 204 months). Angiographic variables analyzed was proximal and distal diameters of arterial grafts(dependent variable), coronary area, TIMI flow grade, proximal stenosis diameter, dominant distal flow and patent branches. Cardiovascular risk factors were included indeed. Results: The multiple regression model demonstrated R2adjusted=0.69 (p=0.0001) for right side and R2adjusted=0.46 (p=0.002) for left side. The grafts presented proximal and distal diameters of 2.67mm ±0.085 and 2.232mm ±0.085 from left side; 2.458mm ±0.088 and 2.010mm ±0.091 (mean±SE) from right side respectively (p > 0,05). None of the clinical variables had statistical significant correlation. The coronary area presented as a beta coefficient=0.42 (0.14-0.6/CI-95%) and proximal stenosis diameter of 0.55 (0.40-0.65/CI-95%) for right side remodeling. The coronary area shown a beta coefficient=0.54 (0.3- 0.68/CI-95%) for left side remodeling. Conclusions: The internal thoracic artery did not demonstrate difference in caliber about its laterality (left vs right). The proximal stenosis degree of the bypassed coronary artery demonstrated positive correlation with remodeling for the right side grafts. Bilateral grafts remodeling was only explained by positive correlation with the bypassed coronary area

Faktoren, die die funktionelle Erholung von hibernating myocardium nach aortokoronarem Venen Bypass (ACVB) beeinflussen, werden gegenwärtig untersucht. Von 3/2000 bis 3/2003 untersuchten wir prospektiv 41 Patienten mit einer linksventrikulären Ejektionsfraktion (LVEF) / Objectives: Factors that influence functional recovery of hibernating myocardium after coronary artery bypass grafting are at present under investigation. Methods: From 3/2000 to 3/2003 we prospectively analyzed 41 patients with ejection fraction (EF) 15% during DE in group I preoperatively; the increase was < 15% in group II. MRI hyperenhancement was measured with a mean of 16,7±11,6% of the left ventricle in group I compared to a mean of 27,4±14,4% in group II (p 19µm) in group I than in group II (< 17µm). Gene expression of pro-apoptotic genes such as BAK and BAX was lowered (0.5±0.1/0.8±0.1) compared to "normal" myocardium (1.0±0.1) (p

INTRODUÇÃO: A cirurgia de revascularização miocárdica sem utilização de circulação extracorpórea (CEC) tem sido cada vez mais utilizada, especialmente após a introdução de dispositivos estabilizadores da parede cardíaca. Entretanto, a técnica pode causar alterações hemodinâmicas durante a realização das anastomoses coronárias. OBJETIVOS: Analisar as alterações hemodinâmicas decorrentes das mudanças de posição do coração para abordar as artérias coronárias sem CEC e comparar os monitores de débito cardíaco semi-contínuo e de ecodoppler transesofágico quanto à precisão das medidas hemodinâmicas. MATERIAL E MÉTODOS: Foram selecionados aleatoriamente 20 pacientes adultos com idade inferior a 80 anos, candidatos a cirurgia eletiva de revascularização miocárdica sem utilização de circulação extracorpórea. A avaliação hemodinâmica incluiu a utilização de ecodopppler com transdutor esofágico e de cateter de artéria pulmonar com filamento térmico. A coleta de dados foi realizada: 1 - após a indução da anestesia, antes do início da revascularização propriamente dita, 2 - durante a realização das anastomoses distais, logo após o posicionamento e estabilização do coração e 3 - após cinco minutos do início da anastomose. Os dados hemodinâmicos foram analisados por análise de variância de duplo fator com repetição, complementada por teste de Newman-Keuls. O nível de significância considerado foi de 5%. Os valores de débito cardíaco foram comparados segundo método proposto por Bland e Altman, analisando a correlação intraclasses, diferenças médias e intervalos de confiança de 95%. RESULTADOS: Alterações hemodinâmicas significativas foram detectadas para o aumento de pressão de oclusão de artéria pulmonar (de 17,7 ± 6,1 para 19,2 ± 6,5 mmHg - p<0,001 e para 19,4 ± 5,8 mmHg - p<0,001) e pressão venosa central (de 13,9 ± 5,4 para 14,9 ± 5,9 mmHg - p=0,007 e para 15,1 ± 6,0 mmHg - p=0,006), além de diminuição do débito cardíaco obtido por termodiluição intermitente (de 4,70 ± 1,43 para 4,23 ± 1,22 L/min - p<0,001 e para 4,26 ± 1,27 L/min - p<0,001). Houve interação grupo-tempo estatisticamente significativa no débito cardíaco por Doppler esofágico, que apresentou redução no grupo lateral de 4,08 ± 1,99 para 2,84 ± 1,81 L/min (p=0,02) e para 2,86 ± 1,73 L/min (p=0,02), e no fluxo sanguíneo aórtico, que diminuiu de 2,85 ± 1,39 para 1,99 ± 1,26 L/min (p=0,02) e para 2,00 ± 1,21 L/min (p=0,02). As medidas de débito cardíaco intermitente, semicontínuo e por Doppler esofágico apresentaram diferenças médias e intervalos de confiança de 95% acima de limites aceitáveis clinicamente. CONCLUSÕES: Houve deterioração hemodinâmica significativa durante a revascularização miocárdica sem CEC. Pelo Doppler esofágico, o débito cardíaco apresentou redução detectada apenas na parede lateral. As diferenças nos valores de débito cardíaco foram muito amplas para considerar os métodos concordantes, em quaisquer das condições hemodinâmicas estudadas. / INTRODUCTION: Coronary artery bypass graft (CABG) surgeries have been performed increasingly without cardiopulmonary bypass (off-pump CABG), specially with introduction of cardiac wall stabilizing devices. However, hemodynamic changes can occur during coronary anastomosis. OBJECTIVES: To study hemodynamic alterations caused when cardiac position is changed to operate coronary arteries and to compare continuous cardiac output and esophageal Doppler monitor regardig accuracy of hemodynamic measurements. MATERIALS AND METHODS: Twenty adult patients under age of 80 undergoing elective off-pump CABG were enrolled. Hemodynamic evaluation was performed with esophageal echodoppler and continuous thermodilution pulmonary artery catheter. Data were collected 1 - after induction of anesthesia, before revascularization, 2 - during distal anastomosis, right after heart positioning and stabilization, and 3 - five minutes following the beginning of anastomosis. Repeated measures two-way ANOVA with post hoc Newman-Keuls tests were used to analyse hemodynamic data and level of significance was set at 0.05. Cardiac output values were compared using the method proposed by Bland and Altman, and included analysis of correlation, mean differences and 95% confidence intervals. RESULTS: Significant hemodynamic alterations were detected during revascularization of coronary arteries as elevation of pulmonary artery occlusion pressure (from 17.7 ± 6.1 to 19.2 ± 6.5 mmHg - P <0.001, and to 19.4 ± 5.8 mmHg - P <0.001) and of central venous pressures (from 13.9 ± 5.4 to 14.9 ± 5.9 mmHg - P =0.007, and to 15.1 ± 6.0 mmHg - P =0.006), and as reduction of intermittent cardiac output (from 4.70 ± 1.43 to 4.23 ± 1.22 l/min - P <0.001, and to 4.26 ± 1.27 l/min - P <0.001). Statistically significant group-time interaction was observed in esophageal Doppler cardiac output, that decreased in the lateral wall from 4.08 ± 1.99 to 2.84 ± 1.81 l/min (P =0.02) and to 2.86 ± 1.73 l/min (P =0.02), and in aortic blood flow, that decreased from 2.85 ± 1.39 to 1.99 ± 1.26 l/min (P =0,02) and to 2.00 ± 1.21 l/min (P =0.02). Intermittent, STAT-mode or esophageal Doppler cardiac output mean differences and 95% confidence intervals were beyond clinically acceptable limits. CONCLUSIONS: There was significant hemodynamic deterioration during off-pump CABG. On the esophageal Doppler monitor, cardiac output decrease was detected only in the lateral wall. Differences in cardiac output measurements were too wide to say methods agreed, in all hemodynamic conditions studied.

Made available in DSpace on 2016-08-19T18:16:06Z (GMT). No. of bitstreams: 1 dissertacao Lea.pdf: 69266 bytes, checksum: f60351433176b7ed5ac2e326bfa1bf71 (MD5) Previous issue date: 2012-04-20 / Objective: To compare the mortality of men and women undergoing coronary artery bypass surgery (CABG) alone and identifying factors related differences occasionally found. Methods: Retrospective cohort study conducted with 215 patients who underwent coronary bypass surgery consecutively from January 2007 to December 2008. Results: Women had a higher average age. Low body surface and dyslipidemia was more prevalent in women (1.65 vs. 1.85, p <0.001: 53% vs 30%, p = 0.001), whereas smoking history and previous myocardial infarction were more prevalent among men (35 % vs 14.7% p = 0.001, 20% vs 2.7%, p = 0.007). Regarding the complications in the postoperative period, there was a higher rate of transfusions in women. The overall mortality rate was 5.6%, however there was no statistically significant difference in mortality between men and women. It was observed that among patients who died the mean body surface was lower than that of patients who progressed without this complication. Conclusion: There was no difference in mortality between the sexes after CABG in our department. / Objetivo: Comparar a morbimortalidade de homens e mulheres submetidos à cirurgia de revascularização isolada e identificando fatores relacionados as diferenças eventualmente encontradas. Métodos: Estudo de Coorte retrospectivo realizado com 215 pacientes, submetidos a cirurgia de revascularização miocárdica isolada, consecutivamente, de janeiro de 2007 a dezembro de 2008. Resultados: As mulheres apresentaram idade media mais elevada. Baixa superfície corpórea e dislipidemia foram mais prevalentes nas mulheres (1,65 vs 1,85, p<0,001: 53% vs 30%, p=0,001), enquanto história de tabagismo e infarto do miocárdio prévio foram mais prevalentes nos homens (35% vs 14,7%p=0,001; 20% vs 2,7%, p=0,007). Em relação às complicações no pós-operatório, houve maior taxa de transfusão de hemoderivados nas mulheres. A taxa de mortalidade geral foi de 5,6%, no entanto não houve diferença estatisticamente significante na mortalidade entre homens e mulheres. Foi observado que entre os pacientes que evoluíram para óbito a media da superfície corpórea era menor que a dos pacientes que evoluíram sem essa complicação. Conclusão: Não houve diferença de mortalidade entre os sexos após revascularização miocárdica neste serviço.

Orientador: Regina Paolucci El Dib / Resumo: Cirurgias cardíacas são procedimentos muito eficientes para tratar os sintomas do infarto miocárdico, e para realizar trocas e plastias valvares. Contudo, problemas clínicos ocorrem ao realizar-se tais procedimentos em razão da lesão de isquemia-reperfusão e estresse oxidativo. Ambos, a cirurgia e a circulação extracorpórea (CEC) causam liberação de citocinas inflamatórias (TNF-α, IL-6, IL-10) e ativação de espécies reativas de oxigênio (O2-, H2O2-). Glutationa peroxidase (GPO) é uma enzima antioxidante que exerce papel importante no equilíbrio oxidativo e tem sua atividade limitada pela depleção das reservas de glutationa (GSH). N-acetilcisteína (NAC) é um resíduo acetilado do composto cisteína, e é necessária à ressíntese da glutationa (GSH). Estudos têm demonstrado a ação antioxidante da NAC, e seus efeitos na proteção da função dos pulmões, rins e coração, com resultados conflitantes. Sendo assim, este estudo avaliou o papel da n-acetilcisteína na redução da morbimortalidade de pacientes submetidos a cirurgias cardíacas. Foi realizada uma revisão sistemática e metanálise de ensaios clínicos randomizados (ECRs) e quase-ECRs, sem restrições quanto a línguas. ECRs foram pesquisadas nas seguintes bases de dados: MEDLINE, EMBASE, CENTRAL e LILACS, e a última busca ocorreu em 10 de outubro de 2018. Dois revisores independentes (JEGP, RED) selecionaram e extraíram os dados dos estudos, e a abordagem GRADE foi utilizada para classificar a certeza das evidências para os desfechos ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Cardiac surgeries are very efficient procedures to treat acute myocardial infarction symptoms, and to perform heart valve repair or replacement. Nervertheless, clinical issues arise upon performing such procedures, like isquemia-reperfusion injury and oxidative stress. Both, surgery and the cardiopulmonary by-pass (CPB) cause liberation of inflammatory cytokines (TNF-α, IL-6, IL-10) and activation of reactive oxygen species (O2-, H2O2-). Glutathione peroxidase (GPO) is an enzymatic antioxidant and plays a major role on the oxidative balance, and its activity is limited due to glutathione (GSH) reserve depletion. N-acetylcysteine (NAC) is an acetylated residue of the cysteine compound, and is necessary for glutathione (GSH) resynthesis. Studies have demonstrated the antioxidant action of NAC, and its effects on the protection of lung, kidney and heart functions, although with conflicting results. Therefore, this study evaluated the role of NAC on the reduction of morbimortality of the patients submitted to cardiac surgeries. A Systematic review and metanalysis of randomized controlled trials (RCTs) and Quasi-RCTs, with no restrictions to languages, was performed. RCTs were searched from the following databases: MEDLINE, EMBASE, CENTRAL and LILACS, and the last search date was October 10th, 2018. Two independent reviewers have selected and extracted the data from the studies, and the GRADE approach was utilized to classify the certainty of the evidences for the outcomes assesse... (Complete abstract click electronic access below) / Doutor

Background: The 30-day readmission rate is considered a quality of care measure for providers and has become important because providers might face reduced reimbursement from any increase in unplanned readmissions Objective: The aim of the first chapter is to investigate the waiting-length of stay (WLOS) and post-length of stay (PLOS) on the 30-day readmission. In the second chapter, we examined the hospital procedural volume and hospital quality on the 30-day readmission. Our objective in the third chapter is to examine the zip code-level SES factors on the 30-day readmission rates. Participants: patients undergoing isolated coronary artery bypass grafting (CABG) in Virginia Methods: A retrospective study design has been conducted using a multi-level logistic model of increasing complexity for all three chapters. The sample used was from the Virginia Cardiac Surgery Quality Initiative (VCSQI) of the periods 2008-2014, the dataset included patient characteristics. Afterward, we merged the sample with both the Virginia Health Information (VHI) to obtain hospital characteristics (ownership, teaching status, and location), and Agency for Healthcare Research and Quality (AHRF) to obtain county-socio-economic status (SES) characteristics (education, employment, and median household income), the previous SES was used for chapter’s one and two. In chapter three, instead of AHRF, we merged the sample with the American Community Survey (ACS) to obtain zip code-SES characteristics (employment, median household income, education, median house price). The main outcome was the 30-day readmission rate. The analytical sample of chapter one n = 22,097, in chapter two the sample n = 25,531, while in chapter three the sample n= 25,829. We conducted a sensitivity analysis in all three chapters. In chapter one we analyzed the data at the patient level, in chapter two we analyzed the data at the hospital level, while in chapter three we conducted the analysis at the area zip code level. Results: In chapter one, we found that readmitted patients after a prolonged PLOS had increased odds of readmission, by 68.7%, compared to readmitted patients with a shorter PLOS in the fully adjusted model; while, WLOS was not significant at the P < 0.05. In chapter two, the fully adjusted model displayed significant results with a reduced odds in readmissions by 22.8% in the middle-volume hospitals compared to the low-volume hospitals, while the middle-quality hospitals had increased odds of readmission by 23.5% compared to the low-quality hospitals. In chapter three, statistically, we did not find that area zip code-SES had an effect on the 30-day readmission rate. While, geographically, we found that addresses of individuals were clustered in certain areas of Virginia. Conclusion: In chapter one, patients undergoing CABG and experience a prolonged PLOS of > 6 days are at risk to be readmitted within 30-days of the procedure. In chapter two, the higher volume hospitals (middle-volume) compared to low-volume hospitals showed a significant reduction in odds in the 30-day readmissions, especially after adjusting the model with hospital quality. In chapter three, even though, there was no association of area-SES with 30-day readmission, in the maps, we found a cluster of patient addresses in the southern parts of Virginia with an increased readmission, which is considered underprivileged area; and the fact might be due to the proximity of these areas to cardiovascular hospitals. Policy Implication: In chapter one, the study provided a model for clinicians to stratify patients at risk of readmission, especially patients with risks of staying longer in the hospital after CABG. In chapter two, policymakers and the CMS should find new ways to help hospitals with low-volumes to reduce their isolated-CABG readmission rates and be able to compete with high-volume hospitals. In chapter three, no significant correlation between area-SES and readmission for patients who underwent CABG was found; these backs prior notion that SES should not be adjusted for the reimbursement penalties of the Hospital Readmission Reductions Program (HRRP) on hospitals

<p>The aim was to study pathophysiological mechanisms and risk factors for developing atrial fibrillation (AF) after coronary artery bypass grafting (CABG), and the effect of thoracic epidural anaesthesia (TEA).</p><p>The study comprised 141 patients undergoing CABG, including 45 patients randomised for TEA intra- and postoperatively. All patients underwent 24-hour Holter monitoring pre- and postoperatively for the analysis of arrhythmias and heart rate variability (HRV). Catecholamines and neuropeptides (reflecting sympathetic and parasympathetic activity), atrial peptides and echocardiographically assessed atrial arias were obtained pre- and postoperatively.</p><p>Logistic regression analysis identified body mass index (BMI), maximum supraventricular beats (SPB) per minute, and total amount of cardioplegia as independent predictors of postoperative AF. Patients developing AF showed limited diurnal variation of HRV preoperatively. All HRV parameters decreased significantly in all patients postoperatively. The significant postoperative increase in atrial areas and atrial peptides did not differ between patients developing AF and those who did not. TEA had no effect on the incidence of postoperative AF, but resulted in lower heart rate, less increase in adrenaline levels, and decreased neuropeptide levels (reflecting sympathetic and parasympathetic activity). AF was initiated by an SPB in 72.4% of non-TEA and 100% of TEA treated patients, whereas changes in heart rate only, before onset, were seen in 17.2% non-TEA patients.</p><p>The observed risk factors, SPB and cardioplegia, may both induce electrophysiological changes known to increase the susceptibility to AF. The observed postoperative atrial dilatation and autonomic imbalance, indicated by HRV and neuropeptide levels, may further favour the development of AF. The observation that a majority of postoperative AF was initiated by a premature atrial contraction supports our hypothesis that latent atrial foci may be a major trigger mechanism of postoperative AF.</p>

<p>Deep breathing exercises are widely used in the postoperative care to prevent or reduce pulmonary complications, but no scientific evidence for the efficacy has been found after coronary artery bypass grafting (CABG) surgery. </p><p>The aim of the thesis was to describe postoperative pulmonary function and to evaluate the efficacy of deep breathing exercises performed with or without a blow bottle device for positive expiratory pressure (PEP) 10 cmH₂O or an inspiratory resistance-positive expiratory pressure (IR-PEP) mask with an inspiratory pressure of -5 cmH₂O and an expiratory pressure of +10 to +15 cmH₂O. </p><p>Patients undergoing CABG were instructed to perform 30 slow deep breaths hourly during daytime for the first four postoperative days. Patient management was similar in the groups, except for the different breathing techniques. </p><p>Measurements were performed preoperatively, on the fourth postoperative day and four months after surgery. The immediate effect of the deep breathing exercises was examined on the second postoperative day. Pulmonary function was assessed by spirometry, diffusion capacity for carbon monoxide and arterial blood gases. Atelectasis was determined by chest roentgenograms or spiral computed tomography (CT). </p><p>Lung volumes were markedly reduced on the fourth postoperative day. Four months after surgery the pulmonary function was still significantly reduced. On the second and fourth postoperative day all patients had atelectasis visible on CT. A single session of deep breathing exercises performed with or without a mechanical device caused a significant reduction in atelectasis and an improvement in oxygenation. No major differences between deep breathing performed with or without a blow bottle or IR-PEP-device were found, except for a lesser decrease in total lung capacity in the blow bottle group on the fourth postoperative day. Patients who performed deep breathing exercises after CABG had significantly smaller atelectasis and better pulmonary function on the fourth postoperative day compared to a control group who performed no exercises.</p>

<p>The primary aim was to register the incidence of surgical wound infections (SWI) in sternotomy and leg incisions and potential risk factors for SWI following coronary artery by-pass graft (CAGB) procedures. Patients’ perspectives of SWI and the subsequent treatment were also considered. </p><p>Risk factors were registered for 374 patients. Patients were contacted by telephone 30 and 60 days after surgery and interviewed according to a questionnaire about symptoms and signs of wound infections. SWI was defined according to The Centers for Disease Control. Patients with mediastinitis were also interviewed within four months about how they experienced care, how they coped and how they thought the mediastinitis would influence their future life. </p><p>SWIs were diagnosed in 30 % of the patients. Seventy-three percent of the SWIs of the leg were diagnosed within 30 days of surgery and 27% were diagnosed within 31 to 60 days. Female gender and use of a monofilament suture for skin closure were the most important risk factors for SWI of the leg. Low preoperative haemoglobin concentration was the most important risk factor for sternal SWI. Patients with mediastinitis had higher BMI and had more often received erythrocyte transfusions on postoperative day 2 or later than those without infections. Patients without a diagnosis of diabetes who had increased blood glucose concentrations during the intermediate postoperative period had an increased risk of mediastinitis. It was not possible to separate the effect of diabetes as a risk factor for SWI from that of hyperglycaemia as such. Patients’ experiences were influenced by the staffs’ medical knowledge, how care was given and how well information was provided. Perceived danger and stress influenced how they coped with the situation. The patients believed that the mediastinitis would not affect the final outcome of the CABG procedure, even though their confidence in this was influenced by uncertainties about the rehabilitation process.</p>

The aim was to study pathophysiological mechanisms and risk factors for developing atrial fibrillation (AF) after coronary artery bypass grafting (CABG), and the effect of thoracic epidural anaesthesia (TEA). The study comprised 141 patients undergoing CABG, including 45 patients randomised for TEA intra- and postoperatively. All patients underwent 24-hour Holter monitoring pre- and postoperatively for the analysis of arrhythmias and heart rate variability (HRV). Catecholamines and neuropeptides (reflecting sympathetic and parasympathetic activity), atrial peptides and echocardiographically assessed atrial arias were obtained pre- and postoperatively. Logistic regression analysis identified body mass index (BMI), maximum supraventricular beats (SPB) per minute, and total amount of cardioplegia as independent predictors of postoperative AF. Patients developing AF showed limited diurnal variation of HRV preoperatively. All HRV parameters decreased significantly in all patients postoperatively. The significant postoperative increase in atrial areas and atrial peptides did not differ between patients developing AF and those who did not. TEA had no effect on the incidence of postoperative AF, but resulted in lower heart rate, less increase in adrenaline levels, and decreased neuropeptide levels (reflecting sympathetic and parasympathetic activity). AF was initiated by an SPB in 72.4% of non-TEA and 100% of TEA treated patients, whereas changes in heart rate only, before onset, were seen in 17.2% non-TEA patients. The observed risk factors, SPB and cardioplegia, may both induce electrophysiological changes known to increase the susceptibility to AF. The observed postoperative atrial dilatation and autonomic imbalance, indicated by HRV and neuropeptide levels, may further favour the development of AF. The observation that a majority of postoperative AF was initiated by a premature atrial contraction supports our hypothesis that latent atrial foci may be a major trigger mechanism of postoperative AF.