Effect of preservation solution and distension pressure on saphenous vein's endothelium.

OBJECTIVES: Approaches to improve saphenous vein (SV) patency in coronary artery bypass graft (CABG) surgery remain relevant. This study aimed to evaluate the effects of different preservation solutions and different pressures of intraluminal distention on the endothelium of SV segments in CABG. METHODS: Forty-two SV segments obtained from 12 patients undergoing CABG were divided into 7 groups. Group 1 (control) was prepared without preservation or intraluminal distension, while the other 6 groups were preserved in autologous heparinized autologous arterial blood or normal saline (NS), with distention pressures 30, 100 and 300 mmHg. To assess the effects of using these solutions and pressures on the endothelium, the grafts were analysed by scanning electron microscopy, with the measurement of endothelial damage degree. RESULTS: Segments in group 1 showed minimal endothelial damage. SV grafts preserved with NS had significantly greater endothelial damage both compared to the control group and compared to groups preserved with autologous arterial blood (P < 0.001). Segments distended with pressures up to 100 mmHg showed less damage when compared to those distended at 300 mmHg, with the ones subjected to higher pressures presenting a maximum degree of damage, with considerable loss and separation of endothelial cells, extensive foci of exposure of the basement membrane and numerous fractures of the intimate layer, without differences regarding the solution used. CONCLUSIONS: Preparation of SV using NS and with intraluminal distension pressures above 100 mmHg is factors related to increased damage to the venous endothelium.

Dual platelet antiaggregation therapy after myocardial revascularization surgery.

Coronary artery bypass graft (CABG) is a consolidated treatment in patients with coronary artery disease (CAD) for both symptom control and improvement of prognosis. The patency of venous grafts is still the most vulnerable point of the surgical treatment since it presents a high prevalence of occlusion both in the immediate postoperative period and in the long-term follow-up. Aspirin plays a well-established role in this setting, and for a long time, clopidogrel use has been restricted to patients allergic to aspirin. Recently, subgroup analyses of studies with different anti-platelet therapies have shown reduced mortality and cardiovascular events in patients on dual anti-platelet antiplatelet therapy (DAPT) undergoing CABG, although such studies have not been designed to evaluate this patient profile. However, there is still an insufficient number of randomized studies using DAPT in this context, resulting in a disagreement between the European and American cardiology societies guidelines regarding their indication and generating doubts in clinical practice.

Dual platelet antiaggregation therapy after myocardial revascularization surgery

SUMMARY Coronary artery bypass graft (CABG) is a consolidated treatment in patients with coronary artery disease (CAD) for both symptom control and improvement of prognosis. The patency of venous grafts is still the most vulnerable point of the surgical treatment since it presents a high prevalence of occlusion both in the immediate postoperative period and in the long-term follow-up. Aspirin plays a well-established role in this setting, and for a long time, clopidogrel use has been restricted to patients allergic to aspirin. Recently, subgroup analyses of studies with different anti-platelet therapies have shown reduced mortality and cardiovascular events in patients on dual anti-platelet antiplatelet therapy (DAPT) undergoing CABG, although such studies have not been designed to evaluate this patient profile. However, there is still an insufficient number of randomized studies using DAPT in this context, resulting in a disagreement between the European and American cardiology societies guidelines regarding their indication and generating doubts in clinical practice.

RESUMO A cirurgia de revascularização miocárdica (CRM) é tratamento fundamental em pacientes com doença arterial coronariana (DAC) tanto para controle de sintomas quanto para melhora do prognóstico. A patência dos enxertos venosos ainda hoje é o ponto mais vulnerável do tratamento cirúrgico, por apresentar alta prevalência de oclusão tanto no pós-operatório imediato como no seguimento em longo prazo. A aspirina tem papel bem estabelecido neste cenário e, por muito tempo, o uso do clopidogrel ficou restrito a pacientes alérgicos a aspirina. Recentemente, análises de subgrupos de estudos com diferentes terapias antiplaquetárias demonstraram redução de mortalidade e eventos cardiovasculares em pacientes em uso de dupla antiagregação plaquetária (Dapt) submetidos à CRM, ainda que tais estudos não tenham sido desenhados para avaliar este perfil de pacientes. Contudo, há ainda uma quantidade insuficiente de estudos randomizados com uso de Dapt nesse contexto, resultando em uma discordância entre as diretrizes europeia e americana de cardiologia quanto à sua indicação e gerando dúvidas na prática clínica.

Intraoperative analysis of flow dynamics in arteriovenous composite y grafts

Abstract Objective: Composite graft of left internal thoracic artery and great saphenous vein in revascularization of the left coronary system is a technique well described in literature. The aim of this study is to analyze blood flow dynamics in this configuration of composite graft especially in what concerns left internal thoracic artery's adaptability and influence of great saphenous vein segment on left internal thoracic artery's flow. Methods: Revascularization of left coronary system with composite graft, with left internal thoracic artery revascularizing the anterior interventricular artery and a great saphenous vein segment, anastomosed to the left internal thoracic artery, revascularizing another branch of the left coronary system, was performed in 23 patients. Blood flow was evaluated by transit time flowmetry in all segments of the composite graft (left internal thoracic artery proximal segment, left internal thoracic artery distal segment and great saphenous vein segment). Measures were performed in baseline condition and after dobutamine-induced stress, without and with non-traumatic temporary clamping of the distal segments of the composite graft. Results: Pharmacological stress resulted in increase of blood flow values in the analyzed segments (P<0.05). Non-traumatic temporary clamping of great saphenous vein segment did not result in statistically significant changes in the flow of left internal thoracic artery distal segment, both in baseline condition and under pharmacological stress. Similarly, non-traumatic temporary clamping of left internal thoracic artery distal segment did not result in statistically significant changes in great saphenous vein segment flow. Conclusion: Composite grafts with left internal thoracic artery and great saphenous vein for revascularization of left coronary system, resulted in blood flow dynamics with physiological adaptability, both at rest and after pharmacological stress, according to demand. Presence of great saphenous vein segment did not alter physiological blood flow dynamics in distal segment of left internal thoracic artery.

Fluxometria intraoperatória do enxerto composto de artéria torácica interna esquerda e veia safena magna

Enxerto composto de artéria torácica interna esquerda (ATIE) e veia safena magna (VSM) na revascularização de duas ou mais artérias do sistema coronariano esquerdo (SCE)é uma técnica descrita na literatura desde a década de 1980. Apesar de recentes estudos demonstrarem que a ATIE é capaz de oferecer fluxo sanguíneo adequado, para duas ou mais artérias do SCE, tanto em situação de repouso como estresse, estudos aprofundados devem ser desenvolvidos para aprimorar esse conhecimento. O objetivo deste trabalho é analisar a dinâmica de fluxo sanguíneo neste tipo de enxerto composto, sobretudo no que concerne a adaptabilidade da ATIE eà influência da presença do segmento de VSM sobre o fluxo na ATIE.Em vinte e três pacientes foirealizadoenxerto composto em Y de ATIE e VSM, para revascularizar a artéria interventricular anterior (AIA) e outro ramo do SCE, respectivamente, sem circulação extracorpórea (CEC). O fluxo sanguíneomédio, parâmetros de perviedade do enxerto(fração diastólica e índice de pulsatilidade)e reserva de fluxo coronariano(RFC) foram avaliados por meio de fluxometria por tempo de trânsito (FMTT)em todos os segmentos do enxerto composto, ou seja, nos segmentos proximal e distal da ATIE e no segmento de VSM. As medidas foram realizadas em condição basal, e após estresse farmacológico com dobutamina, bem como sem e com clampeamento temporário a traumático dos segmentos distais do enxerto composto.Estresse farmacológico resultou em aumento dos valores do fluxo sanguíneo em todos os segmentos analisados(p<0,05)...

Composite graft of left internal thoracic artery (LITA) and great saphenous vein (GSV) in the revascularization of two or more arteries of the left coronary system (LCS) is a technique described in literature since the 1980s. Despite recent studies demonstrating that LITA is capable of providing adequate blood flow for two or more LCS arteries, both in basal condition and under stress, deeper studies must be developed to improve this knowledge. The objective of this study was to analyze blood flow dynamics in this kind of composite graft, specially in what concerns to LITA adaptability and to the influence of GSV segment on LITA flow. In 23 patients, a LITA and GVS composite Y-graft was realized to the anterior interventricular artery (AIA) and to another LCS branch, respectively, without extracorporeal circulation. Mean blood flow, as well as parameters of graft patency (diastolic fraction and pulsatile index) and coronary flow reserve(CFR)were evaluated throughtransit time flowmetry (TTFM) in all segments of the composite graft, which are LITA proximal and distal segments, and GSV segment. The measures were realized in basal condition and after dobutamine-induced pharmacological stress, as well as without and with non-traumatic temporary clamping of the distal segments of composite graft. Pharmacological stress resulted in increased values of blood flow in all analyzed segments (p<0,05)...

Associação entre o uso da chupeta e a diminuição do risco de morte súbita em bebês / Relation between the use of pacifier and the reduction of cot death

Objetiva-se nesse artigo realizar um levantamento na literatura sobre a associação entre o uso de chupetas na prevenção de morte súbita em crianças. Foi realizada uma revisão de literatura e escolhidos 34 artigos publicados entre os anos de 1978 e 2012 em bancos de dados como PubMed e Scielo, usando os descritores: "morte súbita", "chupetas" e "SIDS". À medida que a mortalidade infantil vem sendo reduzida devido às melhorias socioeconômicas, ambientais e na assistência médica, as mortes súbitas na infância (MSI) tendem a assumir papel relativamente mais importante. Concluiu-se que, de acordo com a literatura, o uso de chupeta por lactentes vem reduzindo consideravelmente a incidência de morte súbita dos mesmos (AU)

The aim of this study was to present a literature review about the use of pacifiers use in the prevention of sudden infant death. A search was conducted in PubMed and SciELO, for studies published between 1978 and 2012 using the key words: "sudden death", "pacifiers", and "SIDS". Thirty four studies were selected. As infant mortality has been reduced due to socioeconomics and environmental improvements, as well as to better medical care, there is a tendency to dedicate greater attention to the sudden infant death syndrome (SIDS). It was concluded that according to the literature the use of pacifiers may reduce considerably the incidence of sudden death of them (AU)

Doppler echocardiographic criteria in patency assessment of composite grafts from left internal thoracic artery.

OBJECTIVES: The purpose of our study was to establish, with an entirely noninvasive method, transthoracic Doppler echocardiography, criteria for patency of composite left internal thoracic artery grafts when placed on the left anterior descending artery and other branches of the left coronary system. METHODS: The control group comprised 20 patients with single graft and 20 patients with composite graft; all forty having their patency confirmed by coronary angiogram (CA). In this control group, two Doppler echocardiographic variables, diastolic mean velocity-time and integral diastolic peak velocity to systolic peak velocity ratio were recorded. For each variable, established cut-off points were established, using the ROC (Receiver Operator Characteristic) curves, to identify criteria which could differentiate the composite grafts. Only patients with composite grafts were included in the 159-patients study group. The criteria established by the cut-off points in the control group were then applied to detect patency using a diastolic fraction of > 0.5 as the gold standard. The sensitivity, specificity, and positive and negative predictive values of these two criteria were determined. RESULTS: In the control group, cut-off points of 0.71 and 0.09 m were established for the diastolic peak velocity/systolic peak velocity ratio and for diastolic mean velocity-time integral, respectively. In the study group phase, the sensitivity and negative predictive value of the diastolic peak velocity/systolic peak velocity > 0.71 criterion were 36% and 11%, respectively. Diastolic mean velocity-time integral > 0.09 m criterion, were 40% and 10.48%. The specificities and positive predictive values of each criterion were 100%. CONCLUSION: Values reaching the criteria established for each variable indicate high probability of composite graft patency. Lower values have a large proportion of false negatives and are not conclusive as patency criteria.

Doppler echocardiographic criteria in patency assessment of composite grafts from left internal thoracic artery / Parâmetros Dopplerfluxométricos de perviedade do enxerto composto de artéria torácica interna esquerda

OBJECTIVES: The purpose of our study was to establish, with an entirely noninvasive method, transthoracic Doppler echocardiography, criteria for patency of composite left internal thoracic artery grafts when placed on the left anterior descending artery and other branches of the left coronary system. METHODS: The control group comprised 20 patients with single graft and 20 patients with composite graft; all forty having their patency confirmed by coronary angiogram (CA). In this control group, two Doppler echocardiographic variables, diastolic mean velocity-time and integral diastolic peak velocity to systolic peak velocity ratio were recorded. For each variable, established cut-off points were established, using the ROC (Receiver Operator Characteristic) curves, to identify criteria which could differentiate the composite grafts. Only patients with composite grafts were included in the 159-patients study group. The criteria established by the cut-off points in the control group were then applied to detect patency using a diastolic fraction of > 0.5 as the gold standard. The sensitivity, specificity, and positive and negative predictive values of these two criteria were determined. RESULTS: In the control group, cut-off points of 0.71 and 0.09m were established for the diastolic peak velocity/systolic peak velocity ratio and for diastolic mean velocity-time integral, respectively. In the study group phase, the sensitivity and negative predictive value of the diastolic peak velocity/systolic peak velocity > 0.71 criterion were 36% and 11%, respectively. Diastolic mean velocity-time integral > 0.09m criterion, were 40% and 10.48%. The specificities and positive predictive values of each criterion were 100%. CONCLUSION: Values reaching the criteria established for each variable indicate high probability of composite graft patency. Lower values have a large proportion of false negatives and are not conclusive as patency criteria.

OBJETIVO: O objetivo deste estudo é estabelecer parâmetros preditores de perviedade, avaliados por Dopplerfluxometria, do enxerto composto de artéria torácica interna esquerda, quando revasculariza a artéria interventricular anterior e outro ramo do sistema esquerdo. MÉTODOS: O grupo controle foi formado por 20 pacientes com enxerto simples e 20 pacientes com enxerto, composto cuja perviedade foi confirmada por cineangiocoronariografia. No grupo controle, as variáveis de fluxo relação velocidade pico diastólico/velocidade pico sistólico e integral da velocidade média/tempo na diástole foram registradas. Para cada variável, estabeleceram-se pontos de corte para identificar enxertos compostos, usando-se curvas ROC (receiver operator characteristic). No grupo estudo, foram avaliados 159 pacientes com enxerto composto, determinando-se os dois parâmetros de fluxo. Pontos de cortes estabelecidos no grupo controle foram usados para determinar sensibilidade, especificidade, valores preditivos positivo e negativo de cada variável relacionada à perviedade dos enxertos, tomando-se como referência a fração diastólica > 0,5. RESULTADOS: No grupo controle, os pontos de corte estabelecidos para as variáveis velocidade pico diastólico/velocidade pico sistólico e integral velocidade média/tempo na diástole foram, respectivamente, 0,71 e 0,09m. No grupo estudo, a sensibilidade para a velocidade pico diastólico/velocidade pico sistólico e integral da velocidade média/tempo na diástole, considerando seus pontos de corte, foi de 36,4% e 40%, respectivamente. Os respectivos valores preditivos negativos foram 11% e 10.48%, enquanto especificidade e valor preditivo positivo foram de 100% para os dois parâmetros. CONCLUSÃO: Valores maiores ou iguais aos estabelecidos para cada variável indicam alta probabilidade de perviedade do enxerto composto. Valores inferiores apresentam grande proporção de falsos negativos, não sendo conclusivos quanto à perviedade.

Experimental model of myocardial infarction induced by isoproterenol in rats.

OBJECTIVE: To evaluate and validate, in our laboratory, the essay of myocardial infarction induced by isoproterenol in rats by means of analysis of hematological, biochemical, oxidative stress markers and histopathological parameters. METHODS: Thirty young, male, Wistar rats (145 to 230 g) were randomly allocated in two groups: Sham group, which underwent a virtual myocardial infarction induction, and the Infarction group, which underwent a myocardial infarction induction with isoproterenol. The administrations for the infarction induction were performed during two consecutive days and a 24-hour interval between them. Twenty-four hours after the last administration, rats from both groups were anesthetized and sacrificed for blood sample collection to evaluate complete blood count (CBC) and biochemical parameters (SGOT, SGPT, troponin I, urea and creatinin), obtain myocardial fragments for oxidative stress markers analyses (catalase activity and glutathione concentrations) as well as histopathological examinations. RESULTS: There were no death cases in the Sham group, while the mortality rate in the Infarction group was 25%. Myocardial infarction induction with isoproterenol raised leukocytes and neutrophils counts, SGOT, troponin I and urea concentrations, reduced catalase enzyme activity and glutathione concentrations in the myocardium and let to histopathological concentrations as well. It did not exert alterations in terms of hemoglobin, SGPT and creatinin concentrations. CONCLUSIONS: The isoproterenol-induced myocardial infarction essay in rats was adequately reproduced in our laboratory, causing alterations in hematological, biochemical, oxidative stress markers and histopathological parameters.

Infected aneurysm of brachial artery after mitral valve infective endocarditis.

We present a case of brachial artery infected aneurysm in a patient with infective endocarditis caused by Streptococcus bovis. A 49-year-old man presented with fever dyspnea and a pansystolic murmur with irradiation to axilla. The echocardiogram revealed vegetation in native mitral valve. After mitral valve replacement with bioprosthesis, it was observed pulsatile mass of five centimeters in diameter at antecubital fossa of right upper limb. It was made the diagnosis of infected aneurysm of the brachial artery, and the surgery was performed successfully. The aim of this case report is to show a rare complication after infective endocarditis.

Modelo experimental de infarto do miocárdio induzido por isoproterenol em ratos / Experimental model of myocardial infarction induced by isoproterenol in rats

OBJETIVO: Avaliar e validar, em nosso meio, o modelo de infarto do miocárdio induzido por isoproterenol em ratos por meio de análises de parâmetros hematológicos, bioquímicos, de marcadores do estresse oxidativo e histopatológicos. MÉTODOS: Trinta ratos jovens, machos, da linhagem Wistar (145 a 230 g), foram alocados aleatoriamente em dois grupos: grupo Simulado, submetido à falsa indução de infarto do miocárdio, e grupo Infarto, submetido à indução do infarto do miocárdio com isoproterenol. As aplicações, para indução do infarto, foram realizadas durante dois dias consecutivos, com intervalo de 24 horas entre elas. Após 24 horas da última aplicação, os ratos de ambos os grupos foram anestesiados e sacrificados para realização de coleta de sangue para hemograma e análise bioquímica (TGO, TGP, troponina I, ureia e creatinina) e coleta de fragmento do miocárdio para avaliação de marcadores do estresse oxidativo (atividade da catalase e concentração de glutationa) e exame histopatológico. RESULTADOS: Não houve mortalidade no grupo Simulado, enquanto a mortalidade no grupo Infarto foi de 25%. A indução do infarto do miocárdio com isoproterenol causou elevação das contagens de leucócitos e neutrófilos, dos níveis de TGO, troponina I e ureia, reduziu a atividade da catalase e os níveis teciduais de glutationa e causou alterações histopatológicas. Não acarretou alterações nas concentrações de hemoglobina, TGP e creatinina. CONCLUSÕES: O modelo de infarto do miocárdio induzido por isoproterenol em ratos foi adequadamente reproduzido em nosso laboratório, acarretando alterações em parâmetros hematológicos, bioquímicos, de marcadores de estresse oxidativo e histopatológicos.

OBJECTIVE: To evaluate and validate, in our laboratory, the essay of myocardial infarction induced by isoproterenol in rats by means of analysis of hematological, biochemical, oxidative stress markers and histopathological parameters. METHODS: Thirty young, male, Wistar rats (145 to 230 g) were randomly allocated in two groups: Sham group, which underwent a virtual myocardial infarction induction, and the Infarction group, which underwent a myocardial infarction induction with isoproterenol. The administrations for the infarction induction were performed during two consecutive days and a 24-hour interval between them. Twenty-four hours after the last administration, rats from both groups were anesthetized and sacrificed for blood sample collection to evaluate complete blood count (CBC) and biochemical parameters (SGOT, SGPT, troponin I, urea and creatinin), obtain myocardial fragments for oxidative stress markers analyses (catalase activity and glutathione concentrations) as well as histopathological examinations. RESULTS: There were no death cases in the Sham group, while the mortality rate in the Infarction group was 25%. Myocardial infarction induction with isoproterenol raised leukocytes and neutrophils counts, SGOT, troponin I and urea concentrations, reduced catalase enzyme activity and glutathione concentrations in the myocardium and let to histopathological concentrations as well. It did not exert alterations in terms of hemoglobin, SGPT and creatinin concentrations. CONCLUSIONS: The isoproterenol-induced myocardial infarction essay in rats was adequately reproduced in our laboratory, causing alterations in hematological, biochemical, oxidative stress markers and histopathological parameters.