Showing papers in "Perfusion in 2014"
TL;DR: The heparin dose correlated better with aPTT relative to ACT and, thus, may be considered a more effective tool for the dosing ofheparin in adult ECMO patients.
Abstract: Introduction:Historically, the activated clotting time (ACT) has been the preferred monitoring test of the heparin effect in extracorporeal membrane oxygenation (ECMO) patients. However, few adult ...
64 citations
TL;DR: Maintaining a high level of MAP (on average) during normothermic CPB does not reduce the risk of postoperative AKI and does not alter the length of hospital stay or the mortality rate.
Abstract: Introduction:We hypothesized that the optimization of renal haemodynamics by maintaining a high level of mean arterial blood pressure (MAP) during cardiopulmonary bypass (CPB) could reduce the rate...
63 citations
TL;DR: The challenges in managing patients with distinct asthma exacerbation phenotypes are highlighted, and the potential need for prolonged device support may alter provider expectations and offers a new perspective of the role of ECCO2R for status asthmaticus.
Abstract: Extracorporeal carbon dioxide removal (ECCO2R) may be indicated for refractory status asthmaticus when severe dynamic hyperinflation or life-threatening respiratory acidosis persists despite optimal medical and ventilator management. Most prior reports describe the application of ECCO2R to rapid-onset asthma exacerbation, requiring a short duration of extracorporeal support. We report two patients with refractory status asthmaticus managed with ECCO2R, emphasizing the use of modern extracorporeal technology, cannulation technique and management protocols, which may improve the risk-to-benefit profile of this strategy. This report highlights the challenges in managing patients with distinct asthma exacerbation phenotypes. The potential need for prolonged device support may alter provider expectations and offers a new perspective of the role of ECCO2R for status asthmaticus.
58 citations
TL;DR: All available data on the benefits of therapeutic phlebotomy point to the importance of monitoring WBV as part of a cardiovascular risk factor, along with other risk-modifying measures, whenever an increased cardiovascular risk is detected.
Abstract: Renewed interest in the age-old concept of "bloodletting", a therapeutic approach practiced until as recently as the 19th century, has been stimulated by the knowledge that blood loss, such as following regular donation, is associated with significant reductions in key hemorheological variables, including whole blood viscosity (WBV), plasma viscosity, hematocrit and fibrinogen. An elevated WBV appears to be both a strong predictor of cardiovascular disease and an important factor in the development of atherosclerosis. Elevated WBV through wall shear stress is the most direct physiological parameter that influences the rupture and erosion of vulnerable plaques. In addition to WBV reduction, phlebotomy may reduce an individual's cardiovascular risk through reductions in excessive iron, oxidative stress and inflammation. Reflecting these findings, blood donation in males has shown significant drops in the incidence of cardiovascular events, as well as in procedures such as percutaneous transluminal coronary angioplasty and coronary artery bypass grafting. Collectively, the available data on the benefits of therapeutic phlebotomy point to the importance of monitoring WBV as part of a cardiovascular risk factor, along with other risk-modifying measures, whenever an increased cardiovascular risk is detected. The development of a scanning capillary tube viscometer allows the measurement of WBV in a clinical setting, which can prove to be valuable in providing an early warning sign of an increased risk of cardiovascular disease.
49 citations
TL;DR: The mechanism, safety and efficacy of volatile anesthetics as inducers of cardiac preconditioning are discussed and recent studies have shown that the use of volatileAnesthetics can mimic the early phase of ischemic preconditionsing through a multi-pathway signaling of mitochondrial KATP channels.
Abstract: The myocardium has an innate ability to protect itself from ischemic events. This protection occurs when the myocardium is exposed to a brief ischemic period prior to a more extreme ischemic event. This is termed ischemic preconditioning. Ischemic preconditioning induces a series of molecular pathways that protect the cardiac myocyte; first, for a period of 1-6 hours (early preconditioning) and, also, for a second period from 24-72 hours (delayed phase). The early preconditioning is mediated by the release of adenosine which induces a protective signal that is related to the mitochondrial KATP channel activation and activation of the δ-opioid and bradykinin receptors. The delayed phase is related to the induction of inducible nitric oxide synthase, superoxide dismutase and heat-shock proteins. Indirect evidence indicates that O2-derived free radicals are involved in the delayed phase, as noted in the early preconditioning phase. Applying ischemic preconditioning to clinical practice can be dangerous and d...
48 citations
TL;DR: SAGE regrets the academic record was compromised by manipulation of the peer review process and apologises to readers.
Abstract: Atherosclerosis is the most serious and common form of cardiovascular disease in which plaque builds up inside the arteries. Peak plaque stress is considered as the main reason for plaque rupture, which results in heart attack and stroke. In the current research, the finite element method is used to anticipate plaque vulnerability, using human samples. A total of 23 healthy and atherosclerotic human coronary arteries (14 healthy and 9 atherosclerotic) were removed within 5 h postmortem. The samples were mounted on a uniaxial tensile test machine and the obtained mechanical properties were used in finite element models. The peak plaque stresses for the Ogden hyperelastic model were compared to the Mooney-Rivlin and Neo-Hookean outcomes. The results indicated that hypocellular plaque in all three models has the highest stress values compared to the cellular and calcified ones and, as a result, is quite prone to rupture. The calcified plaque type, in contrast, has the lowest stress values and remains stable. The results can be used in plaque vulnerability prediction and have clinical implications for interventions and surgeries such as balloon-angioplasty, cardiopulmonary bypass and stenting.
40 citations
TL;DR: The following articles have been retracted for reasons of author misconduct: Fabrication and mechanical characterization of a polyvinyl alcohol sponge for tissue engineering applications, and an experimental study on the elastic modulus of gelatin hydrogels using different stress–strain definitions.
Abstract: Polyvinyl alcohol (PVA) sponges are widely used for clinical applications, including ophthalmic surgical treatments, wound healing and tissue engineering. There is, however, a lack of sufficient data on the mechanical properties of PVA sponges. In this study, a biomechanical method is used to characterize the elastic modulus, maximum stress and strain as well as the swelling ratio of a fabricated PVA sponge (P-sponge) and it is compared with two commercially available PVA sponges (CENEFOM and EYETEC). The results indicate that the elastic modulus of the P-sponge is 5.32% and 13.45% lower than that of the CENEFOM and EYETEC sponges, while it bears 4.11% more and 10.37% less stress compared to the CENEFOM and EYETEC sponges, respectively. The P-sponge shows a maximum strain of 32% more than the EYETEC sponge as well as a 26.78% higher swelling ratio, which is a significantly higher absorbency compared to the CENEFOM. It is believed that the results of this study would help for a better understanding of the extension, rupture and swelling mechanism of PVA sponges, which could lead to crucial improvement in the design and application of PVAbased materials in ophthalmic and plastic surgeries as well as wound healing and tissue engineering.
39 citations
TL;DR: Chest CT and 3D modeling were crucial in assessing whether the TAH-t would fit, as well as postoperative complications in this smaller pediatric patient.
Abstract: Mechanical circulatory support emerged for the pediatric population in the late 1980s as a bridge to cardiac transplantation. The Total Artificial Heart (TAH-t) (SynCardia Systems Inc., Tuscon, AZ) has been approved for compassionate use by the Food and Drug Administration for patients with end-stage biventricular heart failure as a bridge to heart transplantation since 1985 and has had FDA approval since 2004. However, of the 1,061 patients placed on the TAH-t, only 21 (2%) were under the age 18. SynCardia Systems, Inc. recommends a minimum patient body surface area (BSA) of 1.7 m(2), thus, limiting pediatric application of this device. This unique case report shares this pediatric institution's first experience with the TAH-t. A 14-year-old male was admitted with dilated cardiomyopathy and severe biventricular heart failure. The patient rapidly decompensated, requiring extracorporeal life support. An echocardiogram revealed severe biventricular dysfunction and diffuse clot formation in the left ventricle and outflow tract. The decision was made to transition to biventricular assist device. The biventricular failure and clot formation helped guide the team to the TAH-t, in spite of a BSA (1.5 m(2)) below the recommendation of 1.7 m(2). A computed tomography (CT) scan of the thorax, in conjunction with a novel three-dimensional (3D) modeling system and team, assisted in determining appropriate fit. Chest CT and 3D modeling following implantation were utilized to determine all major vascular structures were unobstructed and the bronchi were open. The virtual 3D model confirmed appropriate device fit with no evidence of compression to the left pulmonary veins. The postoperative course was complicated by a left lung opacification. The left lung anomalies proved to be atelectasis and improved with aggressive recruitment maneuvers. The patient was supported for 11 days prior to transplantation. Chest CT and 3D modeling were crucial in assessing whether the device would fit, as well as postoperative complications in this smaller pediatric patient.
36 citations
TL;DR: This study demonstrated that all three vortex pumps produced low levels of haemolysis and are suitable for use in a clinical environment.
Abstract: One challenge in providing extracorporeal circulation is to supply optimal flow while minimising adverse effects, such as haemolysis. To determine if the recent generation constrained vortex pumps with their inherent design improvements would lead to reduced red cell trauma, we undertook a study comparing three devices. Utilizing a simulated short-term ventricular assist circuit primed with whole human blood, we examined changes in plasma free haemoglobin values over a six-day period. The three pumps investigated were the Maquet Rotaflow, the Levitronix PediVAS and the Medos Deltastream DP3.This study demonstrated that all three pumps produced low levels of haemolysis and are suitable for use in a clinical environment. The Levitronix PediVAS was significantly less haemolytic than either the Rotaflow (p<0.05) or the DP3 (p<0.05). There was no significant difference in plasma free haemoglobin between the Rotaflow and the DP3 (p=0.71).
35 citations
TL;DR: SAGE regrets the academic record was compromised by manipulation of the peer review process and apologises to readers.
Abstract: Brain tissue is a very soft tissue in which the mechanical properties depend on the loading direction. While few studies have characterized these biomechanical properties, it is worth knowing that accurate characterization of the mechanical properties of brain tissue at different loading directions is a key asset for neuronavigation and surgery simulation through haptic devices. In this study, the hyperelastic mechanical properties of rat brain tissue were measured experimentally and computationally. Prepared cylindrical samples were excised from the parietal lobes of rats’ brains and experimentally tested by a tensile testing machine. The effects of loading direction on the mechanical properties of brain tissue were measured by applying load on both longitudinal and circumferential directions. The general prediction ability of the proposed hyperelastic model was verified using finite element (FE) simulations of brain tissue tension experiments. The uniaxial experimental results compared well with those predicted by the FE models. The results revealed the influence of loading direction on the mechanical properties of brain tissue. The Ogden hyperelastic material model was suitably represented by the non-linear behavior of the brain tissue, which can be used in future biomechanical simulations. The hyperelastic properties of brain tissue provided here have interest to the medical research community as there are several applications where accurate characterization of these properties are crucial for an accurate outcome, such as neurosurgery, robotic surgery, haptic device design or car manufacturing to evaluate possible trauma due to an impact.
34 citations
TL;DR: Early institution of ECMO should be considered for the management of respiratory failure and refractory shock in the setting of calcium channel blocker overdose when medical therapies are insufficient.
Abstract: A 50-year-old man was admitted to the intensive care unit with respiratory failure and shock after suffering a massive overdose of amlodipine, lisinopril and hydrochlorothiazide. Despite mechanical ventilation, vasopressors, calcium gluconate, hyperinsulinemia-euglycemia therapy, methylene blue and intravenous fat emulsion, the patient's respiratory and hemodynamic status deteriorated. Venoarterial extracorporeal membrane oxygenation (ECMO) was initiated to provide cardiopulmonary support in the setting of profound respiratory failure and refractory shock. The patient was placed on ECMO 19 hours after arrival to the hospital, after which vasopressor and ventilatory requirements decreased significantly. The patient was decannulated from ECMO after 8 days and was discharged home after a 56-day hospitalization. Early institution of ECMO should be considered for the management of respiratory failure and refractory shock in the setting of calcium channel blocker overdose when medical therapies are insufficient.
TL;DR: The reported cases suggest that positioning therapy can be performed safely in ARDS patients treated with vvECMO, providing appropriate precautions are in place and a very experienced team is present.
Abstract: Positioning therapy may improve lung recruitment and oxygenation and is part of the standard care in severe acute respiratory distress syndrome (ARDS). Venovenous extracorporeal membrane oxygenation (vvECMO) is a rescue strategy that may ensure sufficient gas exchange in ARDS patients failing conventional therapy. The aim of this case series was to describe the feasibility and pitfalls of combining positioning therapy and vvECMO in patients with severe ARDS. A retrospective cohort of nine patients is described. The patients received 20 (15-86) hours (median, 25(th) and 75(th) percentile) of positioning therapy while being treated with vvECMO. The initial PaO2/FiO2 index was 64 (51-67) mmHg and the arterial carbon dioxide tension was 60 (50-71) mmHg. Positioning therapy included 135 degrees prone, prone positioning and continuous lateral rotational therapy. During the first three days, the oxygenation index improved from 47 (41-47) to 12 (11-14) cmH2O/mmHg. The lung compliance improved from 20 (17-28) to 42 (27-43) ml/cmH2O. Complications related to positioning therapy were facial oedema (n=9); complications related to vvECMO were entrance of air (n=1) and pump failure (n=1). However, investigation of root causes revealed no association with the positioning therapy and had no documented effect on the outcome. The reported cases suggest that positioning therapy can be performed safely in ARDS patients treated with vvECMO, providing appropriate precautions are in place and a very experienced team is present.
TL;DR: Del Nido CPS can be used for myocardial protection during adult congenital cardiac surgery without any apparent adverse effects, and the proposed benefit is the avoidance of the need for repetitive interruption of the operation to administer multiple doses of standard cardioplegia.
Abstract: Purpose:del Nido cardioplegia solution (CPS) has been successfully used for myocardial protection in the pediatric population. We propose this solution can be used safely in adult congenital patien...
TL;DR: In this article, the variations of cerebral oxygenation during the initiation period of ECMO treatment in a patient with hypercapnic ARDS, which may partly explain the findings of ischemic and/or hemorrhagic complications in conjunction with ECMO.
Abstract: Extracorporeal membrane oxygenation (ECMO) is increasingly used in ARDS patients with hypoxemia and/or severe hypercapnia refractory to conventional treatment strategies. However, it is associated with severe intracranial complications, e.g. ischemic or hemorrhagic stroke. The arterial carbon dioxide partial pressure (PaCO2) is one of the main determinants influencing cerebral blood flow and oxygenation. Since CO2 removal is highly effective during ECMO, reduction of CO2 may lead to alterations in cerebral perfusion. We report on the variations of cerebral oxygenation during the initiation period of ECMO treatment in a patient with hypercapnic ARDS, which may partly explain the findings of ischemic and/or hemorrhagic complications in conjunction with ECMO.
TL;DR: IABP improves cerebral blood flow, particularly in patients with pre-existing heart failure and highly impaired LVEF, Hence, an IABP might be a treatment option to improve cerebral perfusion in selected patients with cerebral misperfusion and simultaneously existing severe heart failure.
Abstract: Background:The current goal of treatment after acute ischemic stroke is the increase of cerebral blood flow (CBF) in ischemic brain tissue. Intra-aortic balloon pump (IABP) counterpulsation in the setting of cardiogenic shock is able to reduce left ventricular afterload and increase coronary blood flow. The effects of an IABP on CBF have not been sufficiently examined. We hypothesize that the use of an IABP especially enhances cerebral blood flow in patients with pre-existing heart failure.Methods:In this pilot study, 36 subjects were examined to investigate the effect of an IABP on middle cerebral artery (MCA) transcranial Doppler (TCD) flow velocity change and relative CBF augmentation by determining velocity time integral changes (ΔVTI) in a constant caliber of the MCA compared to a baseline measurement without an IABP. Subjects were divided into two groups according to their left ventricular ejection fraction (LVEF): Group 1 LVEF >30% and Group 2 LVEF ≤30%.Results:Both groups showed an increase in CBF...
TL;DR: The veno-veno-arterial ECMO setup is described in full detail and different venous cannulas are discussed and a remarkable improvement of all oxygenation parameters is achieved.
Abstract: The use of extracorporeal membrane oxygenation (ECMO) is becoming a popular tool in the treatment of cardiogenic shock. We present two case reports where classical veno-arterial peripherally cannulated ECMO therapy proved insufficient with profuse cerebral hypoxemia. After augmenting the setting into veno-veno-arterial ECMO, we achieved a remarkable improvement of all oxygenation parameters. The simultaneous use of veno-venous and veno-arterial ECMO might display as a novel strategy to counteract the coronary and cerebral hypoxemia in veno-arterial ECMO therapy in patients with therapy-refractory cardiogenic shock or in combined cardiopulmonary failure. In this manuscript, the veno-veno-arterial ECMO setup is described in full detail and different venous cannulas are discussed.
TL;DR: The results are consistent with the hypothesis that the transfusion of PRBCs during CPB may increase postoperative morbidity, however, further studies are needed to confirm a causal relationship between the timing of the transfusions and the clinical outcome and to elucidate putative mechanisms of such an association.
Abstract: Introduction:Cardiac surgery on neonates for the correction of congenital heart defects is usually associated with the transfusion of packed red blood cells (PRBCs) into the cardiopulmonary bypass ...
TL;DR: There is limited high-level evidence available for all of the NIRS devices on the market despite significant outcomes found in these studies, and additional prospective randomized studies should be conducted in order to establish the potential role NirS may play in patient monitoring as well as assessing the efficacy of the multiple devices onThe market.
Abstract: Objective:Cerebral oxygenation monitoring via near-infrared spectroscopy (NIRS) during cardiopulmonary bypass (CPB) is increasingly becoming an accepted and valued component of intraoperative monit...
TL;DR: The hypothesis that using an ECLS for pressure- and flow-controlled circulation after circulatory arrest is superior to conventional CPR is supported.
Abstract: Objective:Sudden cardiac arrest is one of the leading causes of death. Conventional CPR techniques after cardiac arrest provide circulation with reduced and varying blood flow and pressure. We hypothesize that using pressure- and flow-controlled reperfusion of the whole body improves neurological recovery and survival after 15 min of normothermic cardiac arrest.Methods:Pigs were randomized in two experimental groups and exposed to 15 min of ventricular fibrillation (VF). After this period, the animals in the control group received conventional CPR with open chest compression (n=6), while circulation in the treatment group (n=6) was established with an extracorporeal life support system (ECLS) to control blood pressure and flow. Follow-up included the assessment of neurological recovery and magnetic resonance imaging (MRI) for up to 7 days.Results:Five of the six animals in the control group died, one animal was resuscitated successfully. In the treatment group, 1/6 could not be separated from ECLS. Five o...
TL;DR: The 20 µmfilter removed substantially more emboli than the 40 µm filter during cardiopulmonary bypass in this comparison, and persisted across all size groups of emboli larger than the pore size of the 40 mm filter.
Abstract: Objective:To compare the efficiency of 20 and 40 µm arterial line filters during cardiopulmonary bypass for the removal of emboli from the extracorporeal circuit.Methods:Twenty-four adult patients undergoing surgery were perfused using a cardiopulmonary bypass circuit containing either a 20 µm or 40 µm arterial filter (n = 12 in both groups). The Emboli Detection and Classification system was used to count emboli upstream and downstream of the filter throughout cardiopulmonary bypass. The mean proportion of emboli removed by the filter was compared between the groups.Results:The 20 µm filter removed a significantly greater proportion of incoming emboli (0.621) than the 40 µm filter (0.334) (p=0.029). The superiority of the 20 µm filter persisted across all size groups of emboli larger than the pore size of the 40 µm filter.Conclusion:The 20 µm filter removed substantially more emboli than the 40 µm filter during cardiopulmonary bypass in this comparison.
TL;DR: The use of dodecafluoropentane in this murine model of myocardial infarction showed a 60% reduction in infarct size, which justifies the possibility of using nanoparticles to deliver oxygen to hypoxic tissues and justifies further study.
Abstract: Objective:Currently there are no medications that can be administered to help deliver more oxygen to the myocardial region experiencing abnormal perfusion. The purpose of this study was to look at the nanoparticle dodecafluoropentane in an emulsion as an oxygen carrier. Using nanoparticles as an oxygen carrier is advantageous because they are able to carry oxygen past blockages that are obstructing red blood cells (6-8 µm) due to their smaller size (250 nm). With the reintroduction of oxygen to the ischemic muscle tissue, a reduced infarct size should be seen.Methods:Male C57BL/6J mice underwent left anterior descending artery (LAD) ligation using 8-0 monofilament nylon suture. Immediately after ligation of the LAD, the control group received a 200-µl intravenous injection of phosphate buffered saline (PBS). The treated group received a dose of 0.6 ml/kg of dodecafluoropentane diluted to a total volume of 200 µl in PBS. The mice were then allowed to recover from anesthesia and were sacrificed 24 hours aft...
TL;DR: Limited efficacy is suggested for rFVIIa use for refractory hemorrhage in pediatric patients on ECMO support because of two non-catastrophic complications temporally associated with its administration.
Abstract: Background:Medically refractory hemorrhage in patients on ECMO (extracorporeal membrane oxygenation) support can have catastrophic complications. Recombinant-Activated Factor VII (rFVIIa; NovoSeven...
TL;DR: The results indicate that hydroxyethyl starch may be a viable alternative to human albumin in pediatric patients undergoing relatively simple cardiopulmonary bypass surgeries.
Abstract: Human albumin is the conventional cardiopulmonary bypass circuit primer. However, it has high manufacturing costs. Crystalloid and colloid solutions have been developed as alternatives, including a new generation of non-ionic hydroxyethyl starch (HES). The efficacy of hydroxyethyl starch with a 130 molecular weight and substitution degree of 0.4 (hydroxyethyl starch 130/0.4) was compared with human albumin for use in cardiopulmonary bypass surgery in American Society of Anesthesiologists' grade I-II pediatric congenital heart disease patients. Efficacy was evaluated by comparing perioperative hemodynamic parameters, including plasma colloid osmotic pressure, renal function, blood loss, allogeneic blood volumes and plasma volume substitution. The hydroxyethyl starch group exhibited significantly higher preoperative colloid osmotic pressure (p 0.05). Our results indicate that hydroxyethyl starch may be a viable alternative to human albumin in pediatric patients undergoing relatively simple cardiopulmonary bypass surgeries.
TL;DR: The intraoperative, external head-cooling technique during the aortic cross-clamp period has a neuroprotective effect and leads to less short-term cognitive function impairment after CABG surgery.
Abstract: The aim of study was to assess the effects of an intraoperative external head-cooling technique on cognitive dysfunction in the early postoperative period (at the 10th day) in patients after coronary artery bypass graft (CABG) surgery. Patients in Group H (n=25) were cooled with CPB and the intraoperative, external head-cooling technique, patients in Group C (n=25) were cooled only with cardiopulmonary bypass (CPB) to achieve mild hypothermia (33 - 34 °C). Cognitive function was analyzed before the operation and after the surgery using the Mini Mental State Examination (MMSE), the Modified Visual Reproduction Test from the Wechsler Memory Scale, Trail Making (A/B), WAIS--Digit Span (WDS) and WAIS Digit Symbol Substitution Test (WDSST). The incidence of cognitive impairment at the 10th day after the surgery was 36% (n=9) in Group H and 64% (n=16) in Group C (p=0.048). The temperature during the aortic cross-clamp period was associated with a lower rate of cognitive dysfunction (p=0.05, r(2)=0.09). The intraoperative, external head-cooling technique during the aortic cross-clamp period has a neuroprotective effect and leads to less short-term cognitive function impairment after CABG surgery.
TL;DR: Extracorporeal life support for severe ARDS associated with Legionella pneumonia is an effective treatment option when mechanical ventilation fails, especially when introduced early in the course.
Abstract: Purpose:Legionella is a common cause of community-acquired pneumonia (CAP) and is second only to Pneumococcal pneumonia as a cause of severe CAP that requires treatment in an intensive care unit. W...
TL;DR: RAP and VAP perfusion techniques may reduce hemodilution, potentially resulting in less blood transfusions and higher postoperative hematocrits, in patients undergoing cardiac surgery with cardiopulmonary bypass.
Abstract: Objective:Cardiopulmonary bypass can result in hemodilution due to the crystalloid prime, increasing the need for blood transfusion. Alternative perfusion techniques have the potential to decrease this hemodilution. The objective of this study was to determine whether a protocol of retrograde autologous prime (RAP) and venous antegrade prime (VAP) reduces the need for blood transfusion and increases the hematocrit following cardiac surgery.Methods:We performed a retrospective review of 140 consecutive non-randomized patients who underwent cardiac surgery with cardiopulmonary bypass between November 2011 and September 2012. RAP and VAP techniques were used in 70 patients while the other 70 were managed with conventional perfusion strategies. The primary outcome measure was a composite outcome of any blood transfusion or a discharge hematocrit less than 27%.Results:Baseline demographics and patient characteristics were similar between the two groups, with the exception of the RAP/VAP group having a lower ba...
TL;DR: NLR, as a novel cardiovascular risk marker, is an important, simple and inexpensive method which can be used by the cardiologist as a screening inflammation tool to estimate the development of CCC in patients with CTO.
Abstract: Objectives: Previous studies showed the association between the major adverse cardiovascular outcomes and both higher neutrophil and lower lymphocyte counts. We aimed to investigate whether there is an association between the neutrophil-lymphocyte ratio (NLR) value and the development of coronary collateral circulation (CCC) in patients with coronary chronic total occlusion (CTO). Methods: A total of 274 patients with CTO were included in this study. Patients were then classified according to their Rentrop collateral grades as either poor (Rentrop grades 0-1) or good (Rentrop grades 2-3). Clinical information and analyses of blood samples were obtained from a review of the patients’ charts. Results: Although there was no difference between the two groups with regard to cardiovascular risk profiles, the NLR values were significantly higher in the patients who had poorly developed CCC (2.6 + 0.5 vs 2.2 + 0.4, p<0.001). NLR, high-sensitivity C-reactive protein (hs-CRP), white blood cell count (WBC), age, diabetes, fasting glucose levels and body mass index were found to have univariate association with poorly developed CCC (p<0.1). In a multivariate logistic regression model, NLR (odds ratio 1.88, 95% confidence interval (CI) 1.37–2.74; p<0.001), high-sensitivity C-reactive protein and WBC were found to be the independent predictors of poor CCC. In receiver operator characteristic curve analysis, the optimal cut-off value of NLR to predict poor CCC was found as 2.17, with 77% sensitivity and 65% specificity. Conclusion: NLR, as a novel cardiovascular risk marker, is an important, simple and inexpensive method which can be used by the cardiologist as a screening inflammation tool to estimate the development of CCC in patients with CTO.
TL;DR: The automatic segmentation algorithm presented uses wavelet decomposition and reconstruction to select a suitable frequency band for envelope calculations and has been found to be effective in segmenting phonocardiogram signals into four component parts without using an ECG reference.
Abstract: Background:Phonocardiography, the digital recording of heart sounds, is becoming increasingly popular as a primary detection system for diagnosing heart disorders and is relatively inexpensive. The electrocardiogram (ECG) is often used when recording the phonocardiogram in order to help identify the systolic and diastolic components. In this study, a heart sound segmentation algorithm has been developed which automatically separates the heart sound signal into these component parts.Methods:100 patients with normal and abnormal heart sounds were studied. The algorithm uses homomorphic filtering to produce time-domain intensity envelopes of the heart sounds and separates the sounds into four overlapping parts: the first heart sound, the systolic period, the second heart sound and the diastolic period.Results:The performance of the algorithm was evaluated using 14,000 cardiac periods from 100 digital phonocardiographic recordings, including normal and abnormal heart sounds. In tests, the algorithm was over 9...
TL;DR: The authors concluded that the N/L ratio as a novel cardiovascular risk marker is an important, simple and inexpensive method which can be used by the cardiologist as a screening inflammation tool to estimate the development of CCC in patients with CTO.
Abstract: We have eagerly read the article ‘‘The relationship between the neutrophil-lymphocyte (N/L) ratio and the coronary collateral circulation (CCC) in patients with chronic total occlusion (CTO)” by Kalkan et al.1 with interest. In that well-presented study, the authors aimed to investigate whether there is an association between the N/L ratio and the development of CCC in patients with CTO. They concluded that the N/L ratio as a novel cardiovascular risk marker is an important, simple and inexpensive method which can be used by the cardiologist as a screening inflammation tool to estimate the development of CCC in patients with CTO. Coronary collateral circulation is an adaptive response to myocardial ischemia. Well-developed collaterals are associated with reduced mortality in patients with stable coronary artery disease and reduced infarct size in patients with acute myocardial infarction.2 There are interconnecting vessels between the main arteries which can prevent ischemia, despite coronary artery occlusion, in many patients. These interconnections of vessels, which can be visualized and graded by angiography, represent the coronary collateral circulation; an alternative route for myocardial perfusion. In the present study,1 coronary collaterals were scored by visual analyses and were evaluated according to the Rentrop grading system; patients with Rentrop grade 0-1 showed the absence of CCC and they accepted Rentrop grade 2-3 as the presence of CCC. Then, they compared these two groups. In a previous study by Refiker et al.,3 the patients were classified into impaired CCC development (Group 1, Rentrop grades 0-1-2) and adequate CCC (Group 2, Rentrop grade 3). A subgroup analysis of the Rentrop grading system according to each of the four grades might affect the results of the study. It would be better if the authors added subgroup analysis according to the Rentrop grading system. At present, some non-invasive markers of inflammation, like c reactive protein, erythrocyte sedimentation rate and white blood cell, are widely used in many conditions. Recently, the N/L ratio has been widely used to determination the severity of inflammation in cardiovascular disease,4 malignancies,5 diabetes mellitus, hypertension6 and inflammatory diseases such as Behçet’s disease.7 The N/L ratio, as a cost effective, easily accessible and rapid practical method, is a predictor of systemic inflammation.8 In conclusion, the N/L ratio, as a novel cardiovascular risk marker, is an important, simple and inexpensive method which can be used by the cardiologist as a screening inflammation tool to estimate the development of CCC in patients with CTO, as presented in the current study. However, we have suggested that not only N/L ratio, but also other inexpensive inflammatory markers should be considered when the authors evaluate the inflammatory conditions of patients.
TL;DR: Despite the increment of oxidative markers in early periods of ischemia (2nd hour), which was a hypoxic response of ischemic cells, they have decreased markedly in prolonged ischemies, which might have been caused by the opening of some collateral circulation or the destruction of the isChemic cells.
Abstract: Objective:The aim of this study was to determine the relationship between oxidative stress markers and the duration of ischemia in rat mesenteric and peripheral ischemia models.Methods:Forty rats were divided into five equal groups, as follows: rats in Group I (control group) were sacrificed to determine the baseline characteristics of the serum markers; the superior mesenteric artery was clamped via a simple laparotomy to induce mesenteric ischemia in Groups II and III; the right common femoral artery was clamped to induce peripheral ischemia in Groups IV and V. Blood samples were taken at 2 (Groups II and IV) and 6 (Groups III and V) hours after these procedures. The serum total oxidative status (TOS), total antioxidant capacity (TAC), oxidative stress index (OSI) and paraoxonase-1 (PON-1) enzyme activities were evaluated in the samples obtained from each group.Results:The OSI level of the control group was 91.00±5.46 (mean ± SD). The OSI levels taken 2 hours after the induction of mesenteric ischemia a...