Blood mRNA Expression Profiles of Autophagy, Apoptosis, and Hypoxia Markers on Blood Cardioplegia and Custodiol Cardioplegia Groups

Abstract Introduction: Blood cardioplegia (BC) and Custodiol cardioplegia (CC) have been used for a long time in open heart surgery and are highly effective solutions. The most controversial issue among these two is whether there is any difference between them regarding myocardial damage after ischemia surgery. In this study, autophagy, apoptosis, and hypoxia markers were investigated and that way we evaluated the differences between BC and CC patients. Methods: A total of 30 patients were included in this study, using two different cardioplegic solutions. Three different whole blood samples of the patients were taken from a central vein (preoperatively, immediately postoperatively, and one day after surgery). Total ribonucleic acid was extracted from these samples. Quantitative real-time polymerase chain reaction was performed, and changes in gene expression were determined by the 2-∆∆Ct method of relative quantification. Results: In the CC group, Beclin gene expression level was found to be higher and this difference was statistically significant (P=0.0024). Similarly, cysteine-aspartic acid protease (caspase) 9 and hypoxia-inducible factor 1α messenger ribonucleic acid (mRNA) gene expression level increased and were significantly different in the CC group. In the BC group, Beclin and microtubule-associated protein light chain 3 expressions were higher in the samples taken one day after surgery. Caspases 3 and 8 gene expressions were significantly different in the BC group. Conclusion: As a result of the analysis performed between the two cardioplegia groups, it has been shown that CC harms the myocardium more than BC at the level of mRNA expression of related markers.

Comparison of del nido cardioplegia and blood cardioplegia in terms of development of postoperative atrial fibrillation in patients undergoing isolated coronary artery bypass grafting

Abstract Objective: Del Nido cardioplegia (DNC) has been used in pediatric cardiac surgery for many years with a single dose application and its usage in adult cardiac surgery has been increasing in recent years, with results being published. In this study, we aimed to investigate the effect of DNC on the development of postoperative atrial fibrillation (PoAF). Methods: In this retrospective observational comparative study, 255 patients who underwent isolated on-pump coronary artery bypass grafting, between January 2019 and November 2019, were enrolled. The patients were divided into two groups: DNC (n=132) and blood cardioplegia (BC) (n=123). Intraoperative and postoperative data were evaluated and compared in terms of the development of PoAF. Results: We found that the development of PoAF and the length of hospital stay remain significantly higher in the BC group (P=0.044, P<0.001, respectively). In addition, the aortic cross-clamp time and the cardioplegia volume delivered were significantly lower in the DNC group (P=0.042, P<0.001, respectively). In multivariate logistic regression analysis, only higher cardioplegia volume was determined as an independent predictor for PoAF development (OR 1.001; 95% CI 1.000-1.001; P=0.033). We did not found difference between groups in terms of troponin T, inotropic drug support, need for intraaortic balloon pump and mortality. Conclusion: This study showed that DNC can be used safely in adult coronary bypass surgery and PoAF development effect is reduced.

Single-dose del nido cardioplegia vs. blood cardioplegia in aortic valve replacement surgery

Abstract Introduction: In this study, we aimed to compare Del Nido cardioplegia (DNC) with blood cardioplegia (BC) in aortic valve replacement. Methods: A two-year single-institute retrospective cohort study was accomplished. Subjects who underwent aortic valve replacement surgery were divided into two groups (DNC and BC) and outcomes were compared. Results: Preoperative demographics and clinical data of the patients in both groups were similar. The time until cardiac arrest following administration of the first dose of cardioplegia was statistically significantly shorter in the BC group (47.0 sec. 25-103) than in the DNC group (63.0 sec. 48-140) (P=0.012). Cross-clamping time was longer in the BC group (48.7±12.3 min. vs. 41.5±11.8 min.) (P=0.041). Cardiopulmonary bypass time was statistically significantly shorter in the DNC group (BC 60.8±18.5 min., DNC 53.7±15.2 min.) (P=0.046). The rate of postoperative use of intravenous positive inotropic support drugs (dopamine, dobutamine, norepinephrine, etc.) for more than two hours was significantly higher in the BC group (20 [23.5%] in the BC group and nine [17.3%] in the DNC group) (P=0.035). Creatine kinase myocardial band and troponin I levels were slightly lower in patients receiving DNC, but no statistically significant difference was detected. Conclusion: Del Nido cardioplegia is safe and can be used efficiently as an alternative to blood cardioplegia in isolated aortic valve replacement surgery.

Comparison of the operative and postoperative effects of del Nido and blood cardioplegia solutions in cardiopulmonary bypass surgery

Abstract Objective: Our goal was to compare the operative and postoperative effects of del Nido cardioplegia (DN group) and blood cardioplegia (BC group) performed in cardiac surgery. Methods: A total of 83 patients were included, separated into DN group and BC group. The operative and postoperative effects of the two groups were compared for the first 24 hours until extubation. The operative and postoperative complete blood count (CBC), biochemical values and clinical parameters were compared. Results: The first control activated clotting time (ACT) levels in DN group patients were lower (P=0.003) during the operation. The amount of cardioplegia in DN group were lower than that in BC group (P=0.001). The pump outflow and postoperative lactate level of DN group were lower than those of BC group (P=0.005, P=0.018, respectively), as well as the amounts of NaHCO3 (P=0.006) and KCl (P=0.001) used during the operation. The same occurred with the first monocytes (Mo) and mean corpuscular volume (MCV) levels in the postoperative intensive care unit (P=0.006, P=0.002). However, the first glucose level and the eosinophil (Eo) level were higher in DN group (P=0.011, P=0.047, respectively). Conclusion: In the operative evaluation, the amount of cardioplegia, the first ACT levels, the pump outflow lactate level and the amounts of NaHCO3 and KCl in DN group were lower. In postoperative evaluation, measured level of lactate, Mo and MCV in DN group were all lower; their glucose and Eo levels were higher.

Comparison of del nido cardioplegia with blood cardioplegia in coronary artery bypass grafting combined with mitral valve replacement

Abstract Objective: To compare del Nido cardioplegia (DNC) with blood cardioplegia (BC) in coronary artery bypass grafting (CABG) combined with mitral valve replacement. Methods: A 3-year single-center retrospective cohort study was carried out. Subjects who underwent CABG (up to triple bypass) combined with mitral valve replacement were divided into DNC and BC groups. Each group had thirty subjects. Results: Both groups demonstrated similar baseline characteristics, including age, gender, cardiac/non-cardiac comorbidity, and preoperative echocardiographic parameters. Compared with the BC group, the DNC group demonstrated significantly lower cardioplegia volume (BC = 1130.00±194.1 mL, DNC = 884.33±156.8 mL, P=0.001), cardiopulmonary bypass time (DNC = 110.90±12.52 min, BC = 121.70±13.57 min, P=0.002), aortic clamp time (DNC = 91.37±11.58 min, BC = 101.37±13.87 min, P=0.004), and need for intraoperative defibrillation (DNC = 6 events, BC = 21 events, P=0.001). Postoperative creatine kinase-MB levels and troponin levels were significantly lower in the DNC group than in the BC group. Postoperative haemoglobin and haematocrit levels were significantly higher in the DNC group than in the BC group. The intubation period (hours) in intensive care unit (ICU) was significantly small in the BC group (DNC = 8.13±12.21, BC = 6.82±1.57, P=0.037); however, ICU stay, total hospital stay, and postoperative complication rates were not significantly different between them. At pre-discharge echocardiography, the DNC group demonstrated significantly higher ejection fraction rates than the BC group (47.79±5.50 and 45.72±5.86, respectively, P=0.005). Conclusion: DNC presented better intraoperative and postoperative parameters and it is an effective and safe alternative to BC for CABG combined with mitral valve replacement.

Lidocaine and pinacidil added to blood versus crystalloid cardioplegic solutions: study in isolated hearts

Abstract Objective: The present study aimed the functional recovery evaluation after long term of cardiac arrest induced by Custodiol (crystalloid-based) versus del Nido (blood-based) solutions, both added lidocaine and pinacidil as cardioplegic agents. Experiments were performed in isolated rat heart perfusion models. Methods: Male rat heart perfusions, according to Langendorff technique, were induced to cause 3 hours of cardiac arrest with a single dose. The hearts were assigned to one of the following three groups: (I) control; (II) Custodiol-LP; and (III) del Nido-LP. They were evaluated after ischemia throughout 90 minutes of reperfusion. Left ventricular contractility function was reported as percentage of recovery, expressed by developed pressure, maximum dP/dt, minimum dP/dt, and rate pressure product variables. In addition, coronary resistance and myocardial injury marker by alpha-fodrin degradation were also evaluated. Results: At 90 minutes of reperfusion, both solutions had superior left ventricular contractile recovery function than the control group. Del Nido-LP was superior to Custodiol-LP in maximum dP/dt (46%±8 vs. 67%±7, P<0.05) and minimum dP/dt (31%±4 vs. 51%±9, P<0.05) variables. Coronary resistance was lower in del Nido-LP group than in Custodiol-LP (395%±50 vs. 307%±13, P<0.05), as well as alpha-fodrin degradation, with lower levels in del Nido-LP group (P<0.05). Conclusion: Del Nido-LP cardioplegia showed higher functional recovery after 3 hours of ischemia. The analysis of alpha-fodrin degradation showed del Nido-LP solution provided greater protection against myocardial ischemia and reperfusion (IR) in this experimental model.

Cardiopulmonary resuscitation in an average brazilian intensive care unit: should we perform less or better?

Abstract Introduction: Few data can be found about cardiac arrest in the intensive care unit outside reference centers in third world countries. Objective: To study epidemiology and prognostic factors associated with cardiac arrest in the intensive care unit (ICU) in an average Brazilian center. Methods: Between June 2011 and July 2014, 302 cases of cardiac arrest in the intensive care unit were prospectively evaluated in 273 patients (age: 68.9 ± 15 years) admitted in three mixed units. Data regarding cardiac arrest and cardiopulmonary resuscitation were collected in an "Utstein style" form and epidemiologic data was prospectively obtained. Factors associated with do not resuscitate orders, return of spontaneous circulation and survival were studied using binary logistic regression. Statistical package software used was SPSS 19.0 (IBM Inc., USA). Results: Among 302 cardiac arrests, 230 (76.3%) had their initial rhythm recorded and 141 (61.3%) was in asystole, 62 (27%) in pulseless electric activity (PEA) and 27 had a shockable rhythm (11.7%). In 109 (36.1%) cases, cardiac arrest had a suspected reversible cause. Most frequent suspected cardiac arrest causes were hypotension (n=98; 32.5%), multiple (19.2%) and hypoxemia (17.5%). Sixty (19.9%) cardiac arrests had do not resuscitate orders. Prior left ventricle dysfunction was the only predictor of do not resuscitate order (OR: 3.1 [CI=1.03-9.4]; P=0.04). Among patients that received cardiopulmonary resuscitation, 59 (24.4%) achieved return of spontaneous circulation and 12 survived to discharge (5.6%). Initial shockable rhythm was the only return of spontaneous circulation predictor (OR: 24.9 (2.4-257); P=0.007) and survival (OR: 4.6 (1.4-15); P=0.01). Conclusion: Cardiopulmonary resuscitation rate was high considering ICU patients, so was mortality. Prior left ventricular dysfunction was a predictor of do not resuscitate order. Initial shockable rhythm was a predictor of return of spontaneous circulation and survival.

Coronary perfusion pressure during antegrade cardioplegia in on-pump CABG patients

Abstract Objective: The aim of this study was to investigate whether aortic tension estimated by palpation and cardioplegia infusion line pressure provide results equivalent to those obtained with direct aortic intraluminal pressure measurement. Methods: Sixty consecutive patients who underwent coronary artery bypass graft surgeries with extracorporeal circulation were analyzed. Sanguineous cardioplegic solution in a ratio of 4:1 was administered using a triple lumen antegrade cannula. After crossclamping, cardioplegia was infused and aortic root pressure was recorded by surgeon (A) considering the aortic tension he felt in his fingertips. At the same time, another surgeon (B) recorded his results for the same measurement. Concomitantly, the anesthesiologist recorded intraluminal pressure in the aortic root and the perfusionist recorded delta pressure in cardioplegia infusion line. None of the participants involved in these measurements was allowed to be informed about the values provided by the other examiners. Results: The Bland-Altman test showed that a considerable variation between aortic wall tension was found as measured by palpation and by intraluminal pressure, with a bias of -9.911±18.75% (95% limits of agreement: -46.7 to 26.9). No strong correlation was observed between intraluminal pressure and cardioplegia line pressure (Spearman's r=0.61, 95% confidence interval 0.5-0.7; P<0.0001). Conclusion: These findings reinforce that cardioplegia infusion should be controlled by measuring intraluminal pressure, and that palpation and cardioplegia line pressure are inaccurate methods, the latter should always be used to complement intraluminal measurement to ensure greater safety in handling the cardioplegia circuit.

Modalidades de parada cardíaca induzida: hipercalemia e hipocalcemia - revisão de literatura / Modes of induced cardiac arrest: hyperkalemia and hypocalcemia - Literature review

A entrada de sódio e cálcio desempenham efeito chave no miócito submetido à parada cardíaca por hiperpotassemia. Eles provocam edema celular, acidose, consumo de trifosfato de adenosina e desencadeiam processo de morte celular programada. A parada cardíaca provocada por hipocalcemia mantém os níveis intracelulares de trifosfato de adenosina, melhora o rendimento diastólico e reduz o consumo de oxigênio, o que pode ser traduzido em melhor proteção do miócito às lesões provocadas pela parada cardíaca induzida.

The entry of sodium and calcium play a key effect on myocyte subjected to cardiac arrest by hyperkalemia. They cause cell swelling, acidosis, consumption of adenosine triphosphate and trigger programmed cell death. Cardiac arrest caused by hypocalcemia maintains intracellular adenosine triphosphate levels, improves diastolic performance and reduces oxygen consumption, which can be translated into better protection to myocyte injury induced by cardiac arrest.

Paradoxo do cálcio - o que temos a temer? / The calcium paradox - What should we have to fear?

O paradoxo do cálcio foi pela primeira vez citado em 1966 por Zimmerman et al. A partir daí, ganhou grande interesse por parte da comunidade científica internacional devido ao fato da ausência do íon cálcio produzir na célula muscular cardíaca dano semelhante à lesão de isquemia-reperfusão. Apesar de não serem conhecidos todos os mecanismos envolvidos no processo da lesão celular no paradoxo do cálcio, a conexão intercelular mantida somente pelo nexus parece ter papel chave na fragmentação celular. A adição de pequenas concentrações de cálcio, bloqueadores de canal de cálcio, hiponatremia ou hipotermia são importantes para evitar que haja lesão celular no momento da reperfusão com soluções com concentração fisiológica de cálcio.

The calcium paradox was first mentioned in 1966 by Zimmerman et al. Thereafter gained great interest from the scientific community due to the fact of the absence of calcium ions in heart muscle cells produce damage similar to ischemia-reperfusion. Although not all known mechanisms involved in cellular injury in the calcium paradox intercellular connection maintained only by nexus seems to have a key role in cellular fragmentation. The addition of small concentrations of calcium, calcium channel blockers, and hyponatraemia hypothermia are important to prevent any cellular damage during reperfusion solutions with physiological concentration of calcium.

Comparação da dimensão fractal e entropia de Shannon em miócitos de ratos submetidos à cardioplegia utilizando solução histidina-triptofano-cetoglutarato e histidina-triptofano com glutamato / Comparison of fractal dimension and Shannon entropy in myocytes from rats treated with histidine-tryptophan-glutamate and histidine-tryptophan cetoglutarate

Introdução: As soluções que provocam parada cardíaca eletiva estão em constante evolução, porém, o composto ideal ainda não foi encontrado. Os autores comparam uma nova solução cardioplégica com histidina-triptofano-glutamato (Grupo 2) com histidina-triptofano-cetoglutarato (Grupo 1) em modelo de coração isolado de rato. Objetivo: Quantificar a dimensão fractal e entropia de Shannon em miócitos de rato submetidos à cardioplegia utilizando solução histidina-triptofano com glutamato em modelo experimental, considerando-se os marcadores caspase, IL-8 e Ki-67. Métodos: Vinte ratos machos de raça Wistar foram anestesiados e heparinizados. O tórax foi aberto, realizado cardiectomia e infundido 40 ml/Kg de solução cardioplégica apropriada. Os corações foram mantidos por 2 horas na mesma solução a 4ºC e, após esse período, colocados em aparato de Langendorff por 30 minutos com solução de Ringer Locke. Foram feitas análises imunohistoquímicas para caspase, IL-8 e KI-67. Resultados: A dimensão fractal e a entropia de Shannon dos corações submetidos à parada cardíaca eletiva nos grupos 1 e 2 não foram diferentes. Conclusão: A quantidade de informações avaliada pela entropia de Shannon e a distribuição das mesmas (dada pela dimensão fractal) nas lâminas de coração de rato submetidas à cardioplegia com solução histidina-triptofano-acetoglutarato ou histidina-triptofano-glutamato não foram diferentes, o que mostra que a solução de histidina-triptofano-glutamato é tão boa quanto a histidina-triptofano-cetoglutarato na preservação dos miócitos em modelo de coração isolado de rato. .

Introduction: Solutions that cause elective cardiac arrest are constantly evolving, but the ideal compound has not yet been found. The authors compare a new cardioplegic solution with histidine-tryptophan-glutamate (Group 2) and other one with histidine-tryptophan-cetoglutarate (Group 1) in a model of isolated rat heart. Objective: To quantify the fractal dimension and Shannon entropy in rat myocytes subjected to cardioplegia solution using histidine-tryptophan with glutamate in an experimental model, considering the caspase markers, IL-8 and KI-67. Methods: Twenty male Wistar rats were anesthetized and heparinized. The chest was opened, the heart was withdrawn and 40 ml/kg of cardioplegia (with histidine-tryptophan-cetoglutarate or histidine-tryptophan-glutamate solution) was infused. The hearts were kept for 2 hours at 4ºC in the same solution, and thereafter placed in the Langendorff apparatus for 30 min with Ringer-Locke solution. Analyzes were performed for immunohistochemical caspase, IL-8 and KI-67. Results: The fractal dimension and Shannon entropy were not different between groups histidine-tryptophan-glutamate and histidine-tryptophan-acetoglutarate. Conclusion: The amount of information measured by Shannon entropy and the distribution thereof (given by fractal dimension) of the slices treated with histidine-tryptophan-cetoglutarate and histidine-tryptophan-glutamate were not different, showing that the histidine-tryptophan-glutamate solution is as good as histidine-tryptophan-acetoglutarate to preserve myocytes in isolated rat heart. .

Comparação da solução de histidina-triptofano-alfacetoglutarato com histidina-triptofano-glutamato como agentes cardioplégicos em corações isolados de ratos: estudo imuno-histoquímico / Comparison of the solution of histidine-tryptophan-alfacetoglutarate with histidine-tryptophan-glutamate as cardioplegic agents in isolated rat hearts: an immunohistochemical study

Introdução: A parada do coração durante a cirurgia cardíaca é procedimento comum e permite que o cirurgião realize os procedimentos cirúrgicos em ambiente isento de sangue e movimento. Os autores comparam, em modelo de coração isolado de rato, uma nova solução cardioplégica com histidina-triptofano-glutamato (grupo 2) com a histidina-triptofano-alfacetoglutarato (grupo 1) já utilizada de rotina por alguns cirurgiões cardíacos. Objetivo: Avaliar por análise imuno-histoquímica a caspase, a IL-8 e KI-67 em corações isolados de ratos. Métodos: 20 ratos machos de raça Wistar foram anestesiados e heparinizados. O tórax foi aberto, realizado cardiectomia e infundido 40 ml/kg de solução cardioplégica apropriada. Os corações foram mantidos por 2 horas na mesma solução a 4ºC e, após esse período, colocados em aparato de Langendorff por 30 minutos com solução de Ringer Locke. Foram feitas análises imuno-histoquímicas para caspase, IL-8 e KI-67. Resultados: A concentração de caspase estava menor no grupo 2 e da KI-67 estava mais elevada no grupo 2, ambos com P<0,05. Não houve diferença estatística entre os valores de IL-8 entre os grupos. Conclusão: A solução com histidina-triptofano-glutamato foi melhor que a com histidina-triptofano-cetoglutarato, pois reduziu a caspase (apoptose), aumentou o KI-67 (proliferação celular) e não apresentou valores diferentes de IL-8 (inflamação e necrose) que no grupo 1. Isso sugere que a solução histidina-triptofano-glutamato foi mais eficiente que a histidina-triptofano-cetoglutarato na preservação dos cardiomiócitos dos corações de ratos. .

Introduction: Cardiac arrest during heart surgery is a common procedure and allows the surgeon to perform surgical procedures in an environment free of blood and movement. Using a model of isolated rat heart, the authors compare a new cardioplegic solution containing histidine-tryptophan-glutamate (group 2) with the histidine-tryptophan-alphacetoglutarate (group 1) routinely used by some cardiac surgeons. Objective: To assess caspase, IL-8 and KI-67 in isolated rat hearts using immunohistochemistry. Methods: 20 Wistar male rats were anesthetized and heparinized. The chest was opened, cardioctomy was performed and 40 ml/kg of the appropriate cardioplegic solution was infused. The hearts were kept for 2 hours at 4ºC in the same solution, and thereafter, placed in the Langendorff apparatus for 30 minutes with Ringer-Locke solution. Immunohistochemistry analysis of caspase, IL-8, and KI-67 were performed. Results: The concentration of caspase was lower in group 2 and Ki-67 was higher in group 2, both P<0.05. There was no statistical difference between the values of IL-8 between the groups. Conclusion: Histidine-tryptophan-glutamate solution was better than histidine-tryptophan-alphacetoglutarate solution because it reduced caspase (apoptosis), increased KI-67 (cell proliferation), and showed no difference in IL-8 levels compared to group 1. This suggests that the histidine-tryptophan-glutamate solution was more efficient than the histidine-tryptophan-alphacetoglutarate for the preservation of hearts of rat cardiomyocytes. .

Development of cardioplegic solution without potassium: experimental study in rat / Desenvolvimento de solução cardioplégica sem potássio: estudo experimental em ratos

INTRODUCTION: Myocardial preservation during open heart surgeries and harvesting for transplant are of great importance. The heart at the end of procedure has to resume its functions as soon as possible. All cardioplegic solutions are based on potassium for induction of cardioplegic arrest. OBJECTIVE: To assess a cardioplegic solution with no potassium addition to the formula with two other commercially available cardioplegic solutions. The comparative assessment was based on cytotoxicity, adenosine triphosphate myocardial preservation, and caspase 3 activity. The tested solution (LIRM) uses low doses of sodium channel blocker (lidocaine), potassium channel opener (cromakalin), and actin/myosin cross bridge inhibitor (2,3-butanedione monoxime). METHODS: Wistar rats underwent thoracotomy under mechanical ventilation and three different solutions were used for "in situ" perfusion for cardioplegic arrest induction: Custodiol (HTK), Braile (G/A), and LIRM solutions. After cardiac arrest, the hearts were excised and kept in cold storage for 4 hours. After this period, the hearts were assessed with optical light microscopy, myocardial ATP content and caspase 3 activity. All three solutions were evaluated for direct cytotoxicity with L929 and WEHI-164 cells. RESULTS: The ATP content was higher in the Custodiol group compared to two other solutions (P<0.05). The caspase activity was lower in the HTK group compared to LIRM and G/A solutions (P<0.01). The LIRM solution showed lower caspase activity compared to Braile solution (P<0.01). All solutions showed no cytotoxicity effect after 24 hours of cells exposure to cardioplegic solutions. CONCLUSION: Cardioplegia solutions without potassium are promised and aminoacid addition might be an interesting strategy. More evaluation is necessary for an optimal cardioplegic solution development.

INTRODUÇÃO: Preservação do miocárdio durante cirurgias cardíacas abertas e de colheita para transplante são de grande importância. O coração ao final do processo tem de retomar as suas funções, logo que possível. Todas as soluções cardioplégicas são baseadas em potássio, para indução de parada cardioplégica. OBJETIVO: Comparar a uma solução cardioplégica sem adição de potássio à sua fórmula com duas outras soluções cardioplégicas disponíveis comercialmente. A avaliação comparativa foi baseada na citotoxicidade, preservação miocárdica (adenosina trifosfato, ATP) e atividade da caspase 3. A solução testada (LIRM) utiliza baixas doses de bloqueador de canal de sódio (lidocaína), abridor do canal de potássio (cromacalina) e inibidor da ponte actina/miosina (2,3-butanodiona monoxima). MÉTODOS: Ratos Wistar foram submetidos à toracotomia sob ventilação mecânica e três soluções diferentes foram utilizadas para perfusão in situ para a indução de parada cardioplégica: soluções Custodiol (HTK) Braile (G/A) e LIRM. Após parada cardíaca, os corações foram retirados e mantidos em câmara fria por 4 horas. Após esse período, o coração foi avaliado com microscopia de luz ótica, o conteúdo de ATP miocárdico e atividade da caspase 3. Todas as três soluções foram avaliadas quanto à citotoxicidade direta com células L929 e WEHI-164. RESULTADOS: A quantidade de ATP foi maior no grupo Custodiol em comparação às com outras duas soluções (P<0,05). A atividade de caspase foi menor no grupo HTK quando comparado às soluções LIRM e G/A (P<0,01). A solução LIRM demonstrou menor atividade da caspase em comparação à solução Braile (P<0,01). Todas as soluções não mostraram qualquer efeito de citotoxicidade após 24 horas de exposição das células às soluções cardioplégicas. CONCLUSÃO: Soluções cardioplégicas sem potássio são uma perspectiva e a adição de aminoácido pode ser uma estratégia interessante. Mais avaliações são necessárias para o desenvolvimento ideal da solução cardioplégica.

Clinical and ultramicroscopic myocardial randomized study of beating versus arrested heart for mitral surgery / Estudo randomizado clínico e ultramicroscópico na cirurgia valvar mitral com o coração com atividade elétrica versus sem atividade elétrica

INTRODUCTION: Beating heart surgery on normothermic bypass simulates physiologic cardiac status. OBJECTIVES: This study compared clinical and transmission electron microscopic aspects of myocardial protection during mitral valve replacement using warm retrograde perfusion in empty beating versus arrested heart with cold blood anterograde cardioplegia. METHODS: Randomized study to evaluate myocardial cellular ischemia-reperfusion of both techniques to replace the mitral valve. Thirty-four patients were randomly assigned into group A (beating heart) and group B (arrested heart). The following parameters were assessed: echocardiography, blood chemistry, hemoglobin, lactate. During the surgical procedure a total of 102 myocardial biopsies were performed for ultrastructural analysis from anterior left ventricular wall: before cardiopulmonary bypass, before aortic desclamping and 10 minutes after reperfusion. RESULTS: Elevation of lactate at 3 hours during the procedure was higher in group A, but similar at the end of surgery (P=0.06). Cardioversion was necessary in 5/17 (A) vs. 13/17 (B) P=0.07. Median intraoperative systemic temperature was significantly lower in the group B compared to A (32oC vs. 36oC), P<0.001. There was no significant difference of the ultramicroscopic aspects of the heart biopsies before, during and after surgery in both groups. Cellular and mitochondrial transient abnormalities such as mitochondrial swelling, glycogen loss and cytosol swelling were detected independently of the moment of the biopsies. CONCLUSION: Myocardial protection and ultrastructural abnormalities were similar for both types of mitral valve replacement beating or arrested heart techniques.

INTRODUÇÃO: A cirurgia valvar mitral pode ser realizada com o coração com atividade elétrica, vazio e normotérmico com pinçamento aórtico, perfusão sanguínea no seio coronário, simulando um estado fisiológico. OBJETIVOS: Comparar as manifestações clínicas e ultramicroscópicas do miocárdio, na cirurgia valvar mitral, com o coração com atividade elétrica versus sem atividade elétrica. MÉTODOS: Estudo randomizado constituído de 34 pacientes: grupo A (batendo) e grupo B (parado). Os parâmetros foram: hematológico, bioquímico, ecocardiográfico, lactato. Foram realizadas 102 biopsias da parede anterior do ventrículo esquerdo preparadas para análise ultraestrutural: antes da circulação extracorpórea, antes do despinçamento aórtico e 10 minutos após a interrupção da circulação extracorpórea. RESULTADOS: Verificou-se elevação do lactato 3 horas após o início do procedimento, que foi maior no grupo A (P=0,06), todavia semelhantes no final da cirurgia. A cardioversão foi necessária em (A) 5/17 vs. (B) 13/17, P=0,07. A temperatura intraoperatória média foi significativamente menor no grupo B em relação ao grupo A (32oC vs. 36oC), P<0,001. A análise ultramicroscópica das amostras das biopsias do coração antes da circulação extracorpórea, ao término do pinçamento aórtico e após a saída da circulação extracorpórea, revelou anormalidades transitórias semelhantes no citoplasma, núcleos e mitocôndrias em ambos os grupos, independentemente do momento das biopsias. CONCLUSÃO: A proteção miocárdica na cirurgia valvar mitral apresentou aspectos semelhantes na preservação da integridade ultraestrutural dos cardiomiócitos quando realizada com o coração com ou sem atividade elétrica.

Aortic Surgery without Infusion of Cardioplegic Solution at Total Circulatory Arrest

BACKGROUND: Minimal infusion of cardioplegic solution (CPS) during aortic surgery using total circulatory arrest (TCA) may reduce several potential side effects: clamping on a diseased aorta, insult of coronary ostia, and edema. MATERIALS AND METHODS: From 2006 to 2009, 72 patients underwent aortic surgery without infusion of cardioplegic solution at the initiation of circulatory arrest. The diagnoses were acute aortic dissection (44), aneurysm (22), and intramural hematoma (6). RESULTS: The duration of TCA, the lowest nasopharyngeal temperature, bypass time, and aortic clamp time was 45 minutes, 16.4degrees C, 162 minutes, and 100 minutes, respectively. The amount of CPS was 1,050 mL, and 15 patients underwent surgery without CPS. The average inotrope score was 113 points (range, 6.25 to 5,048.5 points) corresponding to the dopamine infusion of 5 mcg/kg/min for 1 day. Seven patients showed a level of creatine kinase-MB above 50 ng/mL, postoperatively, compared with the average of 12.75 ng/mL. The ischemic change was found on electrocardiogram in 5 patients, postoperatively. There was no cardiac morbidity requiring mechanical assist. The average of intensive care unit stay and postoperative hospital stay was 40 hours (range, 15 to 482 hours) and 11 days, respectively. CONCLUSION: Minimal infusion of only retrograde CPS during rewarming without initial infusion at TCA in aortic surgery is feasible and can be used with acceptable results.

Sanguineous normothermic, intermittent cardioplegia, effects on hypertrophic myocardium: morphometric, metabolic and ultrastructural studies in rabbits hearts / Efeitos da cardioplegia sanguínea normotérmica intermitente, em miocárdio hipertrófico: estudos morfométricos, metabólicos e ultraestruturais em corações coelhos

OBJECTIVES: The present investigation aimed to study the protective effect of intermittent normothermic cardioplegia in rabbit's hypertrophic hearts. METHODS: The parameters chosen were 1) the ratio heart weight / body weight, 2) the myocardial glycogen levels, 3) ultrastructural changes of light and electron microscopy, and 4) mitochondrial respiration. RESULTS: 1) The experimental model, coarctation of the aorta induced left ventricular hypertrophy; 2) the temporal evolution of the glycogen levels in hypertrophic myocardium demonstrates that there is a significant decrease; 3) It was observed a time-dependent trend of higher oxygen consumption values in the hypertrophic group; 4) there was a significant time-dependent decrease in the respiratory coefficient rate in the hypertrophic group; 5) the stoichiometries values of the ADP: O2 revealed the downward trend of the values of the hypertrophic group; 6) It was possible to observe damaged mitochondria from hypertrophic myocardium emphasizing the large heterogeneity of data. CONCLUSION: The acquisition of biochemical data, especially the increase in speed of glycogen breakdown, when anatomical changes are not detected, represents an important result even when considering all the difficulties inherent in the process of translating experimental results into clinical practice. With regard to the adopted methods, it is clear that morphometric methods are less specific. Otherwise, the biochemical data allow detecting alterations of glycogen concentrations and mitochondria respiration before the morphometric alterations should be detected.

OBJETIVOS: O presente estudo teve como objetivo estudar o efeito protetor da cardioplegia normotérmica intermitente em corações hipertróficos de coelhos. MÉTODOS: Os parâmetros escolhidos foram: 1) relação peso cardíaco/peso corporal; 2) níveis de glicogênio nos músculos cardíacos; 3) alterações ultraestruturais por microscopia óptica e eletrônica; e 4) respiração mitocondrial. RESULTADOS: 1) O modelo experimental de coarctação da aorta induziu hipertrofia ventricular esquerda; 2) a evolução temporal dos níveis de glicogênio no miocárdio hipertrófico demonstra que há diminuição significativa; 3) observou-se tendência dependente do tempo para maiores valores do consumo de oxigênio para o grupo hipertrófico; 4) houve diminuição dependente do tempo da taxa de coeficiente respiratório no grupo hipertrófico; 5) os valores estequiométricos da ADP: O2 revelou a tendência decrescente no grupo hipertrófico; 6) observaram-se lesões mitocondriais do miocárdio hipertrófico, enfatizando a grande heterogeneidade dos dados. CONCLUSÃO: A aquisição de dados bioquímicos, principalmente o aumento na velocidade de quebra do glicogênio, quando mudanças anatômicas não são detectadas, representa um resultado importante, mesmo quando se consideram todas as dificuldades inerentes ao processo translacional de resultados experimentais para a prática clínica. No que diz respeito aos métodos adotados, é evidente que os métodos morfométricos são menos específicos. Os dados bioquímicos permitem a detecção de alterações das concentrações de glicogênio e respiração mitocondrial antes das alterações morfométricas serem detectadas.

Fatores associados à sobrevida em pacientes submetidos a transplante cardíaco utilizando microcardioplegia sanguínea retrógrada / Associated factors with survivals in patients undergoing orthotopic heart transplant using retrograde blood microcardioplegia

INTRODUÇÃO: Uma grande variedade de técnicas e soluções é utilizada na preservação do coração durante o transplante, o que demonstra a falta de método ideal na prática clínica. A administração da cardioplegia de forma retrógrada propicia perfusão contínua, o que pode conferir melhor recuperação inicial do coração transplantado. O objetivo deste trabalho é descrever a experiência de um único centro onde todos os pacientes receberam a mesma solução de conservação de órgão e foram submetidos a microcardioplegia sanguínea retrógrada contínua durante o implante do enxerto e avaliar fatores de mortalidade precoce e tardia com a utilização desta técnica. MÉTODOS: Este é um estudo retrospectivo, observacional e descritivo, realizado em um único centro. RESULTADOS: No período do estudo, foram realizados 35 transplantes cardíacos, sendo que 15 (42,9%) pacientes encontravam-se em choque cardiogênico. A probabilidade de sobrevida foi 74,8±7,8%, 60,4±11,3% e 15,1±13,4% ao final de 1 ano, 5 anos e 10 anos de seguimento, respectivamente. O tempo médio de sobrevida foi de 96,6 meses. CONCLUSÃO: A utilização da solução cardioplégica para proteção de órgãos e a estratégia de iniciar a perfusão com microcardioplegia sanguínea retrógrada contínua forneceu proteção adequada.

BACKGROUND: Several techniques and cardioplegic solutions have been used for heart preservation during transplant procedures. Unfortunately, there is a lack of ideal method for myocardial preservation in the clinical practice. The use of retrograde cardioplegia provides continuous infusion of cardioplegic solution during the graft implantation. This strategy may provide better initial recovery of the graft. The objective of this study is to describe the experience of a single center where all patients received the same solution for organ preservation and were subjected to continuous retrograde blood microcardioplegia during implantation of the graft and to evaluate factors associated to early and late mortality with this technique. METHODS: This is a retrospective, observational and descriptive study of a single center. RESULTS: During the study period were performed 35 heart transplants. Fifteen (42.9%) patients were in cardiogenic shock. The probability of survival was 74.8±7.8%, 60.4±11.3% and 15.1±13.4% at 1 year, 5 years and 10 years of follow-up, respectively. The median survival time was 96.6 months. CONCLUSION: The use of myocardial protection with retrograde cardioplegic solution may reduce the risks associated morbidity due to cold ischemia time during the heart transplant, and we suggest that this benefit may be even greater in cases of cold ischemia time longer ensuring protection to the myocardium.

Comparative experimental study of myocardial protection with crystalloid solutions for heart transplantation / Estudo comparativo experimental da proteção miocárdica com soluções cristalóides para transplante cardíaco

BACKGROUND: There is a growing need to improve myocardial protection, which will lead to better performance of cardiac operations and reduce morbidity and mortality. Therefore, the objective of this study was to compare the efficacy of myocardial protection solution using both intracellular and extracellular crystalloid type regarding the performance of the electrical conduction system, left ventricular contractility and edema, after being subjected to ischemic arrest and reperfusion. METHODS: Hearts isolated from male Wistar (n=32) rats were prepared using Langendorff method and randomly divided equally into four groups according the cardioprotective solutions used Krebs-Henseleit-Buffer (KHB), Bretschneider-HTK (HTK), St. Thomas-1 (STH-1) and Celsior (CEL). After stabilization with KHB at 37ºC, baseline values (control) were collected for heart rate (HR), left ventricle systolic pressure (LVSP), maximum first derivate of rise left ventricular pressure (+dP/dt), maximum first derivate of fall left ventricular pressure (-dP/dt) and coronary flow (CF). The hearts were then perfused at 10ºC for 5 min and kept for 2 h in static ischemia at 20ºC in each cardioprotective solution. Data evaluation was done using analysis of variance in completely randomized One-Way ANOVA and Tukey's test for multiple comparisons. The level of statistical significance chosen was P<0.05. RESULTS: HR was restored with all the solutions used. The evaluation of left ventricular contractility (LVSP, +dP/ dt and -dP/dt) showed that treatment with CEL solution was better compared to other solutions. When analyzing the CF, the HTK solution showed better protection against edema. CONCLUSION: Despite the cardioprotective crystalloid solutions studied are not fully able to suppress the deleterious effects of ischemia and reperfusion in the rat heart, the CEL solution had significantly higher results followed by HTK>KHB>STH-1.

INTRODUÇÃO: Existe crescente necessidade de aprimorar a proteção miocárdica, para melhor desempenho das operações cardíacas e diminuição da morbimortalidade. Portanto, o objetivo deste estudo foi comparar a eficácia da proteção miocárdica usando tanto solução cristaloide tipo intracelular como extracelular quanto ao desempenho do sistema de condução elétrica, contratilidade do ventrículo esquerdo e edema, após parada isquêmica e posterior reperfusão. MÉTODOS: Corações isolados de ratos Wistar foram montados em Langendorff e aleatoriamente divididos em quatro grupos. de acordo com as soluções cardioprotetoras utilizadas Krebs-Henseleit-Buffer (KHB), Bretschneider-HTK (HTK), St. Thomas-1(STH-1) e Celsior (CEL). Após a estabilização com KHB a 37ºC, valores basais (controle) foram coletados para frequência cardíaca (FC), pressão sistólica do ventrículo esquerdo (PSVE), derivada máxima de aumento da pressão ventricular esquerda (+dP/dt), derivada máxima de queda da pressão ventricular esquerda (-dP/dt) e fluxo coronariano (FCo). Os corações foram então perfundidos a 10ºC por 5 min e mantidos por 2 h em isquemia estática a 20ºC em cada solução cardioprotetora. Avaliação dos dados foi por análise de variância inteiramente casualizados em One-Way ANOVA e teste de Tukey para comparações múltiplas. O nível de significância estatística escolhido foi P<0,05. RESULTADOS: Houve recuperação da FC com todas as soluções utilizadas. A avaliação da contratilidade ventricular esquerda (PSVE, +dP/dt e -dP/dt) demonstrou que o tratamento com a solução CEL foi melhor em comparação às outras soluções. Ao analisar o CF, a solução HTK indicou melhor proteção contra edema. CONCLUSÃO: Apesar das soluções cristaloides cardioprotetoras estudadas não serem capazes de suprimir os efeitos deletérios da isquemia e reperfusão no coração de ratos, a solução CEL apresentou resultado superior seguido por HTK>KHB>STH-1.

Role of δ opioid receptor in brain injury following asphyxial cardiac arrest-resuscitation in rats / 中华麻醉学杂志

Objective To evaluate the role of δ opioid receptor in the brain injury following asphyxial cardiac arrest-resuscitation in rats.Methods Ninety-six pathogen-free male Sprague-Dawley rats,weighing 300-350 g,were randomly divided into 4 groups (n =24 each):sham operation group (group S),asphyxial cardiac arrest-resuscitation group (group M),δ opioid receptor agonist BW373U86 group (group B) and δ opioid receptor antagonist naltrindole group (group N).Cardiac arrest was induced by clamping the tracheal tube for 8 min.Mechanical ventilation with pure oxygen was performed.Epinephrine 0.02 mg/kg and 5％ NaHCO3 1 mg/kg were injected intravenously as soon as chest compression was started.Appearance of spontaneous breathing and MAP ＞ 50 mm Hg (lasting for more than 10 min) were considered to be signs of successful recovery of spontaneous circulation (ROSC).BW373U86 and naltrindole 1 mg/kg were injected via the femoral vein immediately after ROSC in groups B and N,respectively,while the equal volume of normal saline was given instead in groups S and M.Neurological deficit score (NDS) was evaluated at 3,24 and 72 h after ROSC.The rats were then sacrificed,brains were isolated and the hippocampus was obtained for detection of the expression of brain-derived neurotrophic factor (BDNF)and tyrosine receptor kinase B (TrkB)mRNA by RT-PCR.The histological grading (HG) of neurons and number of survival neurons in hippocampal CA1 region were determined at 72 h after ROSC.Results Compared with group S,the expression of BDNF and TrkB mRNA was significantly up-regulated,HG was increased,and NDS and the number of survival neurons were decreased in groups M,B and N (P ＜ 0.05).Compared with group M,the expression of BDNF and TrkB mRNA was significantly up-regulated in group B,the expression of BDNF and TrkB mRNA was down-regulated in group N,and HG was significantly decreased,and NDS and the number of survival neurons were increased in groups B and N (P ＜ 0.05).NDS was significantly lower,the number of survival neurons was smaller,the expression of BDNF and TrkB mRNA was lower,and HG was higher in group N than in group B (P ＜ 0.05).Conclusion Activation of δ opioid receptor can reduce the brain injury following asphyxial cardiac arrest-resuscitation in rats and the mechanism may be related to up-regulation of BDNF and TrkB after activation of δ opioid receptor.

A cardiolipina é o alvo da cardiotoxicidade dos anestésicos locais?: [revisão] / Is cardiolipin the target of local anesthetic cardiotoxicity?: [review]

JUSTIFICATIVA E OBJETIVOS: Os anestésicos locais são amplamente utilizados na prevenção ou na reversão de dor aguda e no tratamento de dor crônica. A reação de cardiotoxicidade induzida pelos anestésicos locais é um evento acidental sem terapia farmacológica, exceto a infusão de intralípides relatados recentemente cujo mecanismo de ação ainda não é bem compreendido. CONTEÚDO: A cardiolipina, um fosfolipídio aniônico, desempenha papel relevante na determinação de reação respiratória mitocondrial, metabolismo de ácidos graxos e apoptose celular. A disfunção do metabolismo energético mitocondrial é sugerida em associação com a cardiotoxicidade dos anestésicos locais, a partir de um estudo in vitro de que ela talvez se deva a fortes ligações eletrostáticas entre os anestésicos locais e a cardiolipina na membrana mitocondrial. Não há, contudo, evidência experimental. Portanto, levantamos a hipótese de que as interações anestésico-cardiolipina sejam o principal determinante associado à reação de cardiotoxicidade, o que pode ser estabelecido com a adoção de métodos teóricos e biológicos estruturais. Esse modelo de interação nos daria uma pista sobre o mecanismo da cardiotoxicidade dos anestésicos locais, visando a futuras pesquisas na área de desenvolvimento de fármacos de prevenção a esse evento na prática clínica. CONCLUSÕES: A interação entre a cardiolipina mitocondrial e os anestésicos locais pode ser a principal fonte de sua cardiotoxicidade, em função de seus efeitos sobre o metabolismo energético e o estado eletrostático.

BACKGROUND AND OBJECTIVES: Local anesthetics are used broadly to prevent or reverse acute pain and treat symptoms of chronic pain. Local anesthetic-induced cardiotoxic reaction has been considered the accidental event without currently effective therapeutic drugs except for recently reported intralipid infusion whose possible mechanism of action is not well known. CONTENTS: Cardiolipin, an anionic phospholipid, plays a key role in determining mitochondrial respiratory reaction, fatty acid metabolism and cellular apoptosis. Mitochondrial energy metabolism dysfunction is suggested as associated with local anesthetic cardiotoxicity, from an in vitro study report that the local anesthetic cardiotoxicity may be due to the strong electrostatic interaction of local anesthetics and cardiolipin in the mitochondria membrane, although there is a lack for experimental evidence. Herein we hypothesized that local anesthetic-cardiolipin interactions were the major determinant of local anesthetic-associated cardiotoxic reaction, established by means of theoretic and structural biological methods. This interacting model would give an insight on the underlying mechanism of local anesthetic cardiotoxicity and provide clues for further in depth research on designing preventive drugs for such inadvertent accidence in routine clinical practice. CONCLUSIONS: The interaction between local anesthetic and mitochondrial cardiolipin may be the underlying mechanism for cardiotoxicity affecting its energy metabolism and electrostatic status.