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Sample records for hemodynamic parameters change

  1. Hemodynamic parameters change earlier than tissue oxygen tension in hemorrhage.

    PubMed

    Pestel, Gunther J; Fukui, Kimiko; Kimberger, Oliver; Hager, Helmut; Kurz, Andrea; Hiltebrand, Luzius B

    2010-05-15

    Untreated hypovolemia results in impaired outcome. This study tests our hypothesis whether general hemodynamic parameters detect acute blood loss earlier than monitoring parameters of regional tissue beds. Eight pigs (23-25 kg) were anesthetized and mechanically ventilated. A pulmonary artery catheter and an arterial catheter were inserted. Tissue oxygen tension was measured with Clark-type electrodes in the jejunal and colonic wall, in the liver, and subcutaneously. Jejunal microcirculation was assessed by laser Doppler flowmetry (LDF). Intravascular volume was optimized using difference in pulse pressure (dPP) to keep dPP below 13%. Sixty minutes after preparation, baseline measurements were taken. At first, 5% of total blood volume was withdrawn, followed by another 5% increment, and then in 10% increments until death. After withdrawal of 5% of estimated blood volume, dPP increased from 6.1% +/- 3.0% to 20.8% +/- 2.7% (P < 0.01). Mean arterial pressure (MAP), mean pulmonary artery pressure (PAP) and pulmonary artery occlusion pressure (PAOP) decreased with a blood loss of 10% (P < 0.01). Cardiac output (CO) changed after a blood loss of 20% (P < 0.05). Tissue oxygen tension in central organs, and blood flow in the jejunal muscularis decreased (P < 0.05) after a blood loss of 20%. Tissue oxygen tension in the skin, and jejunal mucosa blood flow decreased (P < 0.05) after a blood loss of 40% and 50%, respectively. In this hemorrhagic pig model systemic hemodynamic parameters were more sensitive to detect acute hypovolemia than tissue oxygen tension measurements or jejunal LDF measurements. Acute blood loss was detected first by dPP. Copyright (c) 2010 Elsevier Inc. All rights reserved.

  2. Repeated restraint stress produces acute and chronic changes in hemodynamic parameters in rats.

    PubMed

    Sikora, Mariusz; Konopelski, Piotr; Pham, Kinga; Wyczalkowska-Tomasik, Aleksandra; Ufnal, Marcin

    2016-11-01

    Noninvasive hemodynamic measurements in rats require placing animals in restrainers. To minimize restraint stress-induced artifacts several habituation protocols have been proposed, however, the results are inconclusive. Here, we evaluated if a four-week habituation is superior to a shorter habituation, or no habituation. This is the first study comparing different habituation protocols with the use of four-week continuous telemetry measurements. We did the experiments on male, 16-week old, Sprague-Dawley rats. Continuous recordings of mean arterial blood pressure (MABP) and heart rate (HR) were made before and during habituation protocols. Rats were subjected either to control (four weeks of restraint-free recordings, n = 5) or two-week (seven restraints, n = 6) or four-week (14 restraints, n = 6) restraint sessions. The restraint protocols included placement of rats in the middle of the dark phase into plastic restrainers as used for tail-cuff measurements. Restraint lasted for 60 min, and was repeated every second day. Each restraint significantly increased MABP (by 15-25 mmHg) and HR (by 40-120 beats/min). Exposure to the restraint protocols decreased diurnal variation in MABP. There was no hemodynamic adaptation to repeated restraint, and no significant difference in hemodynamic response to restraint among controls, the two-week and the four-week groups. In conclusion, our study indicates that measurements in restrained rats are not likely being made without stress-induced changes in MABP. Moreover, in hemodynamic studies in repeatedly restrained rats longer habituation is not superior to shorter habituation.

  3. Contribution of Social Isolation, Restraint, and Hindlimb Unloading to Changes in Hemodynamic Parameters and Motion Activity in Rats

    PubMed Central

    Tsvirkun, Darya; Bourreau, Jennifer; Mieuset, Aurélie; Garo, Florian; Vinogradova, Olga; Larina, Irina; Navasiolava, Nastassia; Gauquelin-Koch, Guillemette; Gharib, Claude; Custaud, Marc-Antoine

    2012-01-01

    The most accepted animal model for simulation of the physiological and morphological consequences of microgravity on the cardiovascular system is one of head-down hindlimb unloading. Experimental conditions surrounding this model include not only head-down tilting of rats, but also social and restraint stresses that have their own influences on cardiovascular system function. Here, we studied levels of spontaneous locomotor activity, blood pressure, and heart rate during 14 days under the following experimental conditions: cage control, social isolation in standard rat housing, social isolation in special cages for hindlimb unloading, horizontal attachment (restraint), and head-down hindlimb unloading. General activity and hemodynamic parameters were continuously monitored in conscious rats by telemetry. Heart rate and blood pressure were both evaluated during treadmill running to reveal cardiovascular deconditioning development as a result of unloading. The main findings of our work are that: social isolation and restraint induced persistent physical inactivity, while unloading in rats resulted in initial inactivity followed by normalization and increased locomotion after one week. Moreover, 14 days of hindlimb unloading showed significant elevation of blood pressure and slight elevation of heart rate. Hemodynamic changes in isolated and restrained rats largely reproduced the trends observed during unloading. Finally, we detected no augmentation of tachycardia during moderate exercise in rats after 14 days of unloading. Thus, we concluded that both social isolation and restraint, as an integral part of the model conditions, contribute essentially to cardiovascular reactions during head-down hindlimb unloading, compared to the little changes in the hydrostatic gradient. PMID:22768322

  4. A comparative analysis of the dependences of the hemodynamic parameters on changes in ROI's position in perfusion CT scans

    NASA Astrophysics Data System (ADS)

    Choi, Yong-Seok; Cho, Jae-Hwan; Namgung, Jang-Sun; Kim, Hyo-Jin; Yoon, Dae-Young; Lee, Han-Joo

    2013-05-01

    This study performed a comparative analysis of cerebral blood volume (CBV), cerebral blood flow (CBF), mean transit time (MTT), and mean time-to-peak (TTP) obtained by changing the region of interest's (ROI) anatomical positions, during CT brain perfusion. We acquired axial source images of perfusion CT from 20 patients undergoing CT perfusion exams due to brain trauma. Subsequently, the CBV, CBF, MTT, and TTP values were calculated through data-processing of the perfusion CT images. The color scales for the CBV, CBF, MTT, and TTP maps were obtained using the image data. Anterior cerebral artery (ACA) was taken as the standard ROI for the calculations of the perfusion values. Differences in the hemodynamic average values were compared in a quantitative analysis by placing ROI and the dividing axial images into proximal, middle, and distal segments anatomically. By performing the qualitative analysis using a blind test, we observed changes in the sensory characteristics by using the color scales of the CBV, CBF, and MTT maps in the proximal, middle, and distal segments. According to the qualitative analysis, no differences were found in CBV, CBF, MTT, and TTP values of the proximal, middle, and distal segments and no changes were detected in the color scales of the the CBV, CBF, MTT, and TTP maps in the proximal, middle, and distal segments. We anticipate that the results of the study will useful in assessing brain trauma patients using by perfusion imaging.

  5. [The changes of hemodynamic parameters, pathology and c-kit mRNA expression in myocardium after acute myocardial infarction in rats].

    PubMed

    Chen, Shiqian; Long, Weifu; Wu, Wenchao; Jiang, Congxun; Liu, Xiaojing; Li, Liang

    2009-06-01

    This study was aimed to investigate the changes of hemodynamic parameters, pathology and c kit mRNA expression in myocardium after acute myocardial infarctionin (AMI) in rats, and to elucidate the relationship between these three kinds of changes. Sixty six adult male SD rats were randomly divided into normal group, Sham groups and ligation groups. The rat model of AMI was set up by ligating the left anterior descending artery. Hemodynamic parameters, pathological changes and c kit mRNA expression in myocardiam were examined. The results revealed that there were no statistically significant differences in hemodynamic parameters between normal group and Sham groups. Compared with the normal group, all ligation groups exhibited significantly decreased left ventricular systolic pressure (LVSP) and +/-dp/dtmax (P<0.01), and increased left ventricular end diastolic pressure (LVEDP, P<0.01). In the other ligation groups, compared with 6th hour group after ligation, there appeared striking increase of LVSP, LVEDP and +/-dp/dtmax (P<0.05). HE staining in myocardiam showed that there are necrosis and derangement at 24th hour group after ligation ,and a great number of inflammatory cells infiltration around the infarct zone at 3rd day group after ligation, and granulation tissue infiltrated into the infarct zone at 14th day group after ligation. In all five time points groups after ligation, the levels of c-kit mRNA expression were 0.99 fold, 1.06 fold, 1.46 fold, 1.91 fold and 2.67 fold, respectively, compared with Sham groups. The results suggest that cardiac stem cells in myocardium might contribute to the role of regenerating myocardium via self proliferation after acute myocardial infarction, but further investigation is still needed.

  6. Hemodynamic parameters to guide fluid therapy

    PubMed Central

    2011-01-01

    The clinical determination of the intravascular volume can be extremely difficult in critically ill and injured patients as well as those undergoing major surgery. This is problematic because fluid loading is considered the first step in the resuscitation of hemodynamically unstable patients. Yet, multiple studies have demonstrated that only approximately 50% of hemodynamically unstable patients in the intensive care unit and operating room respond to a fluid challenge. Whereas under-resuscitation results in inadequate organ perfusion, accumulating data suggest that over-resuscitation increases the morbidity and mortality of critically ill patients. Cardiac filling pressures, including the central venous pressure and pulmonary artery occlusion pressure, have been traditionally used to guide fluid management. However, studies performed during the past 30 years have demonstrated that cardiac filling pressures are unable to predict fluid responsiveness. During the past decade, a number of dynamic tests of volume responsiveness have been reported. These tests dynamically monitor the change in stroke volume after a maneuver that increases or decreases venous return (preload) and challenges the patients' Frank-Starling curve. These dynamic tests use the change in stroke volume during mechanical ventilation or after a passive leg raising maneuver to assess fluid responsiveness. The stroke volume is measured continuously and in real-time by minimally invasive or noninvasive technologies, including Doppler methods, pulse contour analysis, and bioreactance. PMID:21906322

  7. The multiple parameter hemodynamic imaging system based on ARM

    NASA Astrophysics Data System (ADS)

    Tang, Xuejun; He, Heng; Jiang, Chao; Li, Pengcheng; Luo, Qingming

    2008-12-01

    Optical imaging with high resolution is significant to reveal the functional activities of brain and the mechanism of disease, and has grown into a diverse field. The high-resolution multi-parameters optical imaging system which combines the laser speckle contrast imaging method and optical intrinsic signal imaging method can obtain more hemodynamic information in cortex simultaneously. However, most of current optical imaging systems use He-Ne laser and mercury xenon arc lamp as the light source. Meanwhile, the control unit of the system which includes a personal computer, is not portable. In this paper, we develop a multiple parameters hemodynamic imaging system based on ARM. To make the system more compact, three wavelengths light-emitting diode and laser diode as imaging illuminants were adopted. In addition, the real-time embedded operation system (μC/OS-II) and embedded Graphic User Interface (μC/GUI) were introduced. Animal experimental results also show that changes in oxyhemoglobin, deoxyhemoglobin, total hemoglobin concentration and cerebral blood flow during Cortical Spreading Depression can be simultaneously accessed using this optical imaging system based on embedded ARM.

  8. Hemodynamic Parameters during Laryngoscopic Procedures in the Office and in the Operating Room.

    PubMed

    Tierney, William S; Chota, Rebecca L; Benninger, Michael S; Nowacki, Amy S; Bryson, Paul C

    2016-09-01

    Previous research has shown that office-based laryngoscopic procedures can induce hemodynamic changes, including tachycardia and severe hypertension, calling into question the safety of these procedures. However, comparison between office and operating room (OR) procedures has not been carried out. Therefore, we prospectively measured hemodynamic variables in both settings to compare hemodynamic changes between office and OR procedures. Prospective cohort study. Single academic center. Subjects undergoing office and OR laryngoscopic procedures were prospectively identified, and 92 OR and 70 office subjects were included. Heart rate and blood pressure were measured at established time points before, during, and after the procedures. Descriptive and comparative statistical analyses were conducted. Severe hemodynamic events, either tachycardia or severe hypertension (blood pressure >180 mm Hg systolic or >110 mm Hg diastolic), occurred significantly more frequently in OR than office procedures (41% vs 20%; P = .006). OR severe hemodynamic events occurred more commonly than previously reported rates in the office (41% vs 28%; P = .012). Regression analyses showed that the odds of having a severe hemodynamic event were 3.66 times higher in OR versus office procedures. Severe hemodynamic events are more likely to occur in the OR than in the office during laryngologic procedures. While larger studies will be required to establish rates of dangerous cardiovascular events in laryngoscopic procedures, hemodynamic parameters indicate that office-based procedures have a safety benefit for procedures that can be conducted in either setting. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2016.

  9. Hemodynamic changes during long meditation.

    PubMed

    Solberg, Erik E; Ekeberg, Oivind; Holen, Are; Ingjer, Frank; Sandvik, Leiv; Standal, Per A; Vikman, Agneta

    2004-09-01

    Changes in heart rate (HR) and blood pressure (BP) in advanced male meditators during 1 hr of meditation were compared with matched control participants resting for 1 hr. Also, changes in HR and BP during 3-hr meditation were analyzed. HR was recorded continuously during meditation (n = 38) and the control rest (n = 21). BP was measured before and after the meditation (n = 44) and the rest (n = 30). During the first hour, HR declined more in the meditators than the controls (p < .01). Within participant variability of HR was significantly lower during meditation than rest (p < .05). In the second hour of meditation, HR declined further (p = .01). BP was unaffected by either meditation or rest. In conclusion, meditation reduced the level of HR and within participant variability of HR more than rest. HR continued to decline during the second hour of meditation.

  10. Changes in B-type Natriuretic Peptide and Related Hemodynamic Parameters Following a Fluid Challenge in Critically Ill Patients with Severe Sepsis or Septic Shock

    PubMed Central

    Omar, Shahed; Ali, Ahmad; Atiya, Yahya; Mathivha, Rudo Lufuno; Dulhunty, Joel M.

    2017-01-01

    Context: Severe sepsis or septic shock. Aims: The aim of this study is to examine the effect of a fluid challenge on the B-type natriuretic peptide (BNP) and the hemodynamic state. Settings and Design: This observational study was conducted in an intensivist-led academic, mixed medical-surgical Intensive Care Unit. Subjects and Methods: Focused transthoracic echocardiogram, plasma BNP, and hemodynamic measurements were recorded at baseline and following a 500 ml fluid challenge in thirty patients. Independent predictors of the percentage (%) change in stroke volume (SV) were sought. Next, these independent predictors were assessed for a relationship with the percentage change in BNP. Statistical Analysis Used: Multiple linear regressions, Wilcoxon rank-sum test, t-test, and Pearson's correlation were used. Data analysis was carried out using SAS. The 5% significance level was used. Results: Using a multiple regression models, the percentage increase in SV was independently predicted by the percentage increase in mean arterial pressure, left ventricular end-diastolic volume/dimension (LVEDV/LVEDd), ejection fraction, and a decrease in Acute Physiology and Chronic Health Evaluation II score (P < 0.0001). Preload, measured using LVEDV1 (before the fluid challenge) was significantly larger in the fluid nonresponders (%SV increase <15%) vs. the responders (%SV increase ≥15%). Finally, the percentage change in BNP was positively correlated with left ventricular size at end diastole LVEDd, r = 0.4, P < 0.035). Conclusions: An increase in BNP soon after a fluid challenge may have some predictive utility of a large LVEDd, which in turn can be used to independently predict the SV response to a fluid challenge.

  11. [Study on Indicator Densitometry Determination Method of Hemodynamic Parameters].

    PubMed

    Liu, Guang-da; Zhou, Run-dong; Zha, Yu-tong; Cai, Jing; Niu, Jun-qi; Gao, Pu-jun; Liu, Li-li

    2016-03-01

    Measurement for hemodynamic parameters has always been a hot spot of clinical research. Methods for measuring hemodynamic parameters clinically have the problems of invasiveness, complex operation and being unfit for repeated measurement. To solve the problems, an indicator densitometry analysis method is presented based on near-infrared spectroscopy (NIRS) and indicator dilution theory, which realizes the hemodynamic parameters measured noninvasively. While the indocyanine green (ICG) was injected into human body, circulation carried the indicator mixing and diluting with the bloodstream. Then the near-nfrared probe was used to emit near-infrared light at 735, 805 and 940 nm wavelengths through the sufferer's fingertip and synchronously capture the transmission light containing the information of arterial pulse wave. By uploading the measured data, the computer would calculate the ICG concentration, establish continuous concentration curve and compute some intermediate variables such as the mean transmission time (MTT) and the initial blood ICG concentration (c(t0)). Accordingly Cardiac Output (CO) and Circulating Blood Volume (CBV) could be calculated. Compared with the clinical "gold standard" methods of thermodilution and I-131 isotope-labelling method to measure the two parameters by clinical controlled trials, ten sets of data were obtained. The maximum relative errors of this method were 8.88% and 4.28% respectively, and both of the average relative errors were below 5%. The result indicates that this method can meet the clinical accuracy requirement and can be used as a noninvasive, repeatable and applied solution for clinical hemodynamnic parameters measurement.

  12. Monitoring changes in hemodynamics following optogenetic stimulation

    NASA Astrophysics Data System (ADS)

    Frye, Seth

    The brain is composed of billions of neurons, all of which connected through a vast network. After years of study and applications of different technologies and techniques, there are still more questions than answers when it comes to the fundamental functions of the brain. This project aims to provide a new tool which can be used to gain a better understanding of the fundamental mechanisms that govern neurological processes inside the brain. In order for neural networks to operate, blood has to be supplied through neighboring blood vessels. As such, the increase or decrease in the blood supply has been used as an indicator of neural activity. The neural activity and blood supply relationship is known as neural vasculature coupling. Monitoring the hemodynamics is used as an indicator of neurological activity, but the causal relationship is an area of current research. Gaining a better understanding of the coupling of neural activity and the surrounding vasculature provides a more accurate methodology to evaluate regional neural activity. The new optical technology applied in this project provides a set of tools to both stimulate and monitor this coupling relationship. Optogenetics provides the capability of stimulating neural activity using specific wavelengths of light. Essentially this tool allows for the direct stimulation of networks of neurons by simply shining one color of light onto the brain. Optical Coherence Tomography (OCT), another new optical technology applied in this project, can record volumetric images of blood vessels and flow using only infrared light. The combination of the two optical technologies is then capable of stimulating neural activity and monitoring the hemodynamic response inside the brain using only light. As a result of this project we have successfully demonstrated the capability of both stimulating and imaging the brain using new optical technologies. The optical stimulation of neural activity has evoked a direct hemodynamic effect

  13. Hemodynamics

    PubMed Central

    Secomb, Timothy W.

    2016-01-01

    A review is presented of the physical principles governing the distribution of blood flow and blood pressure in the vascular system. The main factors involved are the pulsatile driving pressure generated by the heart, the flow characteristics of blood, and the geometric structure and mechanical properties of the vessels. The relationship between driving pressure and flow in a given vessel can be understood by considering the viscous and inertial forces acting on the blood. Depending on the vessel diameter and other physical parameters, a wide variety of flow phenomena can occur. In large arteries, the propagation of the pressure pulse depends on the elastic properties of the artery walls. In the microcirculation, the fact that blood is a suspension of cells strongly influences its flow properties and leads to a non-uniform distribution of hematocrit among microvessels. The forces acting on vessel walls include shear stress resulting from blood flow and circumferential stress resulting from blood pressure. Biological responses to these forces are important in the control of blood flow and the structural remodeling of vessels, and also play a role in major disease processes including hypertension and atherosclerosis. Consideration of hemodynamics is essential for a comprehensive understanding of the functioning of the circulatory system. PMID:27065172

  14. Tube-Load Model Parameter Estimation for Monitoring Arterial Hemodynamics

    PubMed Central

    Zhang, Guanqun; Hahn, Jin-Oh; Mukkamala, Ramakrishna

    2011-01-01

    A useful model of the arterial system is the uniform, lossless tube with parametric load. This tube-load model is able to account for wave propagation and reflection (unlike lumped-parameter models such as the Windkessel) while being defined by only a few parameters (unlike comprehensive distributed-parameter models). As a result, the parameters may be readily estimated by accurate fitting of the model to available arterial pressure and flow waveforms so as to permit improved monitoring of arterial hemodynamics. In this paper, we review tube-load model parameter estimation techniques that have appeared in the literature for monitoring wave reflection, large artery compliance, pulse transit time, and central aortic pressure. We begin by motivating the use of the tube-load model for parameter estimation. We then describe the tube-load model, its assumptions and validity, and approaches for estimating its parameters. We next summarize the various techniques and their experimental results while highlighting their advantages over conventional techniques. We conclude the review by suggesting future research directions and describing potential applications. PMID:22053157

  15. Axial penile rigidity: determinants and relation to hemodynamic parameters.

    PubMed

    Goldstein, I; Udelson, D

    1998-05-01

    Erectile dysfunction may be defined in terms of axial penile rigidity, the physical property that enables the erection to be utilized as a penetration tool during sexual activity. Erectile dysfunction occurs when inadequate axial penile rigidity results in buckling of the penile column when subjected to axial compressive loading situations during vaginal intromission. New multi-disciplinary engineering studies of penile hemodynamic and structural dynamic relationships are reviewed concerning the determinants of axial penile rigidity. Axial penile rigidity develops as a continuum during the increases in intracavernosal pressure and volume changes from the flaccid state and is influenced by intracavernosal pressure, penile tissue mechanical properties and penile geometry. Two penile tissue mechanical properties are especially relevant; cavernosal maximum volume at relatively low intracavernosal pressure, and tunical distensibility, the relative volume of the fully erect to completely flaccid pendulous penis. Two penile geometric properties are critical; the penile aspect ratio, defined as the diameter to length ratio of the pendulous penis, and the magnitude of the flaccid penile diameter. Clinically measured values of axial buckling forces in patients undergoing dynamic pharmacocavernosometry strongly correlated to theoretic-based analytic derived magnitudes of axial penile rigidity based on these above pressure, tissue and geometric determinants. Since axial penile rigidity is not exclusively dependent upon intracavernosal pressure, patients with normal erectile hemodynamics may be erroneously labelled as having psychogenic dysfunction where their true pathophysiology may be related to abnormal penile tissue properties and/or penile geometric factors. Similarly, some patients may claim sufficient rigidity for penetration, but have abnormal hemodynamic erectile function studies. They may have uniquely advantageous tissue mechanical and/or geometric properties. More

  16. A parameter estimation framework for patient-specific hemodynamic computations

    NASA Astrophysics Data System (ADS)

    Itu, Lucian; Sharma, Puneet; Passerini, Tiziano; Kamen, Ali; Suciu, Constantin; Comaniciu, Dorin

    2015-01-01

    We propose a fully automated parameter estimation framework for performing patient-specific hemodynamic computations in arterial models. To determine the personalized values of the windkessel models, which are used as part of the geometrical multiscale circulation model, a parameter estimation problem is formulated. Clinical measurements of pressure and/or flow-rate are imposed as constraints to formulate a nonlinear system of equations, whose fixed point solution is sought. A key feature of the proposed method is a warm-start to the optimization procedure, with better initial solution for the nonlinear system of equations, to reduce the number of iterations needed for the calibration of the geometrical multiscale models. To achieve these goals, the initial solution, computed with a lumped parameter model, is adapted before solving the parameter estimation problem for the geometrical multiscale circulation model: the resistance and the compliance of the circulation model are estimated and compensated. The proposed framework is evaluated on a patient-specific aortic model, a full body arterial model, and multiple idealized anatomical models representing different arterial segments. For each case it leads to the best performance in terms of number of iterations required for the computational model to be in close agreement with the clinical measurements.

  17. Bedside calculation of hemodynamic parameters with a hand held programmable calculator. Part II: Programs for hemodynamic and oxygen transport parameters computation.

    PubMed

    Laurent, M

    1980-01-01

    Two programs calculating oxygen transport parameters and hemodynamic values respectively are described. They may be used indifferently with HP 67 or HP 97 Hewlett Packard calculators. (Acta anaesth. belg., 1980, 31, 53-59).

  18. Hemodynamic Consequences of Changes in Microvascular Structure.

    PubMed

    Rizzoni, Damiano; Agabiti-Rosei, Claudia; Agabiti-Rosei, Enrico

    2017-10-01

    In hypertension, an increased media-to-lumen ratio of small resistance arteries might play an important role in the increase of vascular resistance, and may also be an adaptive response to the increased hemodynamic load. The presence of morphological alteration in the microvasculature may be associated to an impaired tissue perfusion and/or to the development of target organ damage. Structural alterations in the microcirculation might represent a predictor of the onset of cardio-cerebrovascular events and hypertension complications. A cross-talk between the small and large artery may exaggerate arterial damage, following a vicious circle. Therefore, in the present review, possible hemodynamic consequences of the presence of microvascular structural alterations will be considered, in terms of their time of onset, role in the development and/or maintenance of high blood pressure values, and interrelationships with structural/mechanical alterations of large conductance arteries. © American Journal of Hypertension, Ltd 2017. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  19. Cerebral Hemodynamic Changes During Intensive Care of Preterm Infants

    PubMed Central

    Limperopoulos, Catherine; Gauvreau, Kimberlee K.; O'Leary, Heather; Moore, Marianne; Bassan, Haim; Eichenwald, Eric C.; Soul, Janet S.; Ringer, Steven A.; Di Salvo, Donald N.; du Plessis, Adré J.

    2009-01-01

    OBJECTIVES The objectives of this study were to examine the circulatory changes experienced by the immature systemic and cerebral circulations during routine events in the critical care of preterm infants and to identify clinical factors that are associated with greater hemodynamic-oxygenation changes during these events. METHODS We studied 82 infants who weighed <1500 g at birth and required intensive care management and continuous blood pressure monitoring from an umbilical arterial catheter. Continuous recording of cerebral and systemic hemodynamic and oxygenation changes was performed. We studied 6 distinct types of caregiving events during 10-minute epochs: (1) quiet baseline periods; (2) minor manipulation; (3) diaper changes; (4) endotracheal tube suctioning; (5) endotracheal tube repositioning; and (6) complex events. Each event was matched with a preceding baseline. We examined the effect of specific clinical factors and cranial ultrasound abnormalities on the systemic and cerebral hemodynamic oxygenation changes that were associated with the various event types. RESULTS There were highly significant differences in hemodynamics and oxygenation between events overall and baseline epochs. The magnitude of these circulatory changes was greatest during endotracheal tube repositioning and complex caregiving events. Lower gestational age, higher illness severity, chorioamnionitis, low Apgar scores, and need for pressor-inotropes all were associated with circulatory changes of significantly lower magnitude. Cerebral hemodynamic changes were associated with early parenchymal ultrasound abnormalities. CONCLUSIONS Routine caregiving procedures in critically ill preterm infants are associated with major circulatory fluctuations that are clinically underappreciated and underdetected by current bedside monitoring. Our data underscore the importance of continuous cerebral hemodynamic monitoring in critically ill preterm infants. PMID:18931348

  20. Changes in tissue perfusion parameters in dogs with severe sepsis/septic shock in response to goal-directed hemodynamic optimization at admission to ICU and the relation to outcome.

    PubMed

    Conti-Patara, Andreza; de Araújo Caldeira, Juliana; de Mattos-Junior, Ewaldo; de Carvalho, Haley da Silva; Reinoldes, Adriane; Pedron, Bruno Gregnanin; Patara, Marcelo; Francisco Talib, Mariana Semião; Faustino, Marcelo; de Oliveira, Clair Motos; Cortopassi, Silvia Renata Gaido

    2012-08-01

    To evaluate the changes in tissue perfusion parameters in dogs with severe sepsis/septic shock in response to goal-directed hemodynamic optimization in the ICU and their relation to outcome. Prospective observational study. ICU of a veterinary university medical center. Thirty dogs with severe sepsis or septic shock caused by pyometra who underwent surgery and were admitted to the ICU. Severe sepsis was defined as the presence of sepsis and sepsis-induced dysfunction of one or more organs. Septic shock was defined as the presence of severe sepsis plus hypotension not reversed with fluid resuscitation. After the presumptive diagnosis of sepsis secondary to pyometra, blood samples were collected and clinical findings were recorded. Volume resuscitation with 0.9% saline solution and antimicrobial therapy were initiated. Following abdominal ultrasonography and confirmation of increased uterine volume, dogs underwent corrective surgery. After surgery, the animals were admitted to the ICU, where resuscitation was guided by the clinical parameters, central venous oxygen saturation (ScvO(2)), lactate, and base deficit. Between survivors and nonsurvivors it was observed that the ScvO(2), lactate, and base deficit on ICU admission were each related independently to death (P = 0.001, P = 0.030, and P < 0.001, respectively). ScvO(2) and base deficit were found to be the best discriminators between survivors and nonsurvivors as assessed via receiver operator characteristic curve analysis. Our study suggests that ScvO(2) and base deficit are useful in predicting the prognosis of dogs with severe sepsis and septic shock; animals with a higher ScvO(2) and lower base deficit at admission to the ICU have a lower probability of death. © Veterinary Emergency and Critical Care Society 2012.

  1. Identification of a hemodynamic parameter for assessing treatment outcome of EDAS in Moyamoya disease.

    PubMed

    Karunanithi, Kaavya; Han, Cong; Lee, Chang-Joon; Shi, Wanchao; Duan, Lian; Qian, Yi

    2015-01-21

    This work is a novel attempt to incorporate computational fluid dynamics (CFD) techniques in the analysis of hemodynamic parameters of Moyamoya disease (MMD). Highly prevalent in Asian countries, MMD is characterised by progressive occlusion of the intracranial Internal Carotid Arteries (ICA). We intend to identify a reliable hemodynamic parameter that can be used to gauge treatment outcome. This will aid surgeons in the perioperative management of MMD patients. We carried out CFD analysis on eight patients (5 female, 3 male) with MMD treated by EDAS (encephalo-duro-arterio-synangiosis) between 2011 and 2012. All the eight patients presented with haemorrhage, with subsequent 4-12 month follow-up done using Magnetic Resonance Angiography (MRA) to capture auto-remodelling. We calculated percentage change in flow rate and pressure drop indicator (ΡDI) across the Left and Right ICA. Pressure drop indicator (PDI) is defined as the difference of pressure reduction within the carotid arteries, measured at post-op and follow up, using patient specific inflow rates. The measured percentage flow change and pressure reduction showed an increase at follow up for improved patients (characterised by angiography according to the method of Matsushima), who did not develop any complications after surgery. The inverse was observed in patients who were clinically classified as no change and retrogressed (according to the method of Matsushima) cases post-operation. This elucidates that our findings have instituted a new parameter that may well play a critical role as an assistive clinical decision making tool in MMD.

  2. Impact of Therapeutic Plasma Exchange on Hemodynamic Parameters in Medical Intensive Care Unit Patients: An Observational Study.

    PubMed

    Lahmer, Tobias; Messer, Marlena; Schnappauf, Christopher; Rasch, Sebastian; Fekecs, Lisa; Beitz, Analena; Eser, Stefan; Schmid, Roland M; Huber, Wolfgang

    2017-02-01

    Therapeutic plasma exchange (TPE) is an extracorporeal treatment with reported beneficial as well as detrimental effects on circulation. However, there is a lack of data using advanced hemodynamic monitoring during TPE. Therefore, we investigated the effects of TPE on hemodynamic parameters derived from transpulmonary thermodilution (TPTD) as well as the risk for transfusion-related acute lung injury (TRALI). We compared hemodynamic parameters obtained before and after a total of 30 sessions of TPE treatment in 10 intensive care unit patients. Among standard hemodynamic parameters, heart rate (P < 0.012) and systolic blood pressure (P < 0.008) significantly increase, whereas neither mean arterial pressure nor diastolic blood pressure was altered after TPE. The TPTD-derived cardiac function parameters, cardiac index (CI; P = 0.035), cardiac power index (CPI; P = 0.008), global ejection fraction (GEF; P = 0.002), and stroke volume index (SVI; P = 0.014), were significantly higher after TPE. Furthermore, systemic vascular index significantly increased (P < 0.042). Among the cardiac preload parameters, central venous pressure was significantly lower after TPE (P < 0.001), while the global end-diastolic volume index (GEDVI) did not change. Contractility marker dPmax did not change. Finally, TPE application did not significantly alter the pulmonary hydration and permeability parameters, extravascular lung water index (EVLWI) and pulmonary vascular permeability index. Vasopressor dose was not statistically significantly altered. Considering increases in SVI, CI, GEF, and CPI and stable values for GEDVI, EVLWI, and dPmax, our data do not give any hint for hemodynamic impairment or TRALI.

  3. Predicting Preoperative Hemodynamic Changes Using the Visual Analog Scale.

    PubMed

    Tanaka, Noriyoshi; Ohno, Yuko; Hori, Megumi; Utada, Mai; Ito, Kenji; Suzuki, Toshiyasu; Furukawa, Fumiko

    2015-12-01

    This study aimed to investigate how both visual analog scale cutoff scores and State-Trait Anxiety Inventory scores relate to hemodynamic changes in patients entering the operating theater. A prospective observational study. The study subjects included 130 prospectively enrolled patients who were scheduled for abdominal surgery under combined epidural-general anesthesia and who underwent preoperative anxiety level measurements using both scales. The heart rate and systolic blood pressure on entering the operating theater were significantly higher than those at baseline in the high and low/moderate anxiety groups. Variations in heart rate and systolic blood pressure were significantly higher, whereas peripheral blood flow was significantly lower in the high anxiety group compared with the low/moderate anxiety group. Using the visual analog scale to measure anxiety can improve our understanding of the hemodynamic changes that occur when patients enter the operating theater. Copyright © 2015 American Society of PeriAnesthesia Nurses. Published by Elsevier Inc. All rights reserved.

  4. Effects of subcortical cerebrovascular lesions on cortical hemodynamic parameters assessed by perfusion magnetic resonance imaging.

    PubMed

    Nighoghossian, N; Berthezene, Y; Adeleine, P; Wiart, M; Damien, J; Derex, L; Itti, R; Froment, J C; Trouillas, P

    1999-01-01

    A simultaneous decrease of cerebral blood volume (CBV) and cerebral blood flow (CBF) has been described after subcortical stroke with positron emission tomography. However, this imaging modality cannot be applied routinely to stroke patients. Dynamic susceptibility contrast-enhanced MRI techniques (DSC-MRI) might be interesting in the assessment of these effects. Dynamic T2-weighted echo planar imaging was used to produce DSC-MR images during an intravenous bolus injection of gadopentetate dimeglumine in 9 patients who experienced a subcortical stroke involving thalamus or basal ganglia and in 8 control subjects. A series of 50 consecutive images at 1-second intervals was acquired at the anatomic level of the centrum semiovale quite distant from the subcortical lesion, rCBF and rCBV were determined over frontal and parietal regions of interest and through the entire cortical mantle. DSC-MRI enabled the detection of hemodynamic changes induced by subcortical stroke. Analysis of rCBV and rCBF values showed that the hemodynamic parameters were significantly decreased on the affected side. In controls mean rCBF and rCBV values recorded over the whole cortical mantle of each hemisphere showed no significant interhemispheric asymmetry.

  5. Hemodynamic and tubular changes induced by contrast media.

    PubMed

    Caiazza, Antonella; Russo, Luigi; Sabbatini, Massimo; Russo, Domenico

    2014-01-01

    The incidence of acute kidney injury induced by contrast media (CI-AKI) is the third cause of AKI in hospitalized patients. Contrast media cause relevant alterations both in renal hemodynamics and in renal tubular cell function that lead to CI-AKI. The vasoconstriction of intrarenal vasculature is the main hemodynamic change induced by contrast media; the vasoconstriction is accompanied by a cascade of events leading to ischemia and reduction of glomerular filtration rate. Cytotoxicity of contrast media causes apoptosis of tubular cells with consequent formation of casts and worsening of ischemia. There is an interplay between the negative effects of contrast media on renal hemodynamics and on tubular cell function that leads to activation of renin-angiotensin system and increased production of reactive oxygen species (ROS) within the kidney. Production of ROS intensifies cellular hypoxia through endothelial dysfunction and alteration of mechanisms regulating tubular cells transport. The physiochemical characteristics of contrast media play a critical role in the incidence of CI-AKI. Guidelines suggest the use of either isoosmolar or low-osmolar contrast media rather than high-osmolar contrast media particularly in patients at increased risk of CI-AKI. Older age, presence of atherosclerosis, congestive heart failure, chronic renal disease, nephrotoxic drugs, and diuretics may multiply the risk of CI-AKI.

  6. Numerical analysis of the effect of turbulence transition on the hemodynamic parameters in human coronary arteries

    PubMed Central

    Gawandalkar, Udhav Ulhas; Kini, Girish; Buradi, Abdulrajak; Araki, Tadashi; Ikeda, Nobutaka; Nicolaides, Andrew; Laird, John R.; Saba, Luca; Suri, Jasjit S.

    2016-01-01

    Background Local hemodynamics plays an important role in atherogenesis and the progression of coronary atherosclerosis disease (CAD). The primary biological effect due to blood turbulence is the change in wall shear stress (WSS) on the endothelial cell membrane, while the local oscillatory nature of the blood flow affects the physiological changes in the coronary artery. In coronary arteries, the blood flow Reynolds number ranges from few tens to several hundreds and hence it is generally assumed to be laminar while calculating the WSS calculations. However, the pulsatile blood flow through coronary arteries under stenotic condition could result in transition from laminar to turbulent flow condition. Methods In the present work, the onset of turbulent transition during pulsatile flow through coronary arteries for varying degree of stenosis (i.e., 0%, 30%, 50% and 70%) is quantitatively analyzed by calculating the turbulent parameters distal to the stenosis. Also, the effect of turbulence transition on hemodynamic parameters such as WSS and oscillatory shear index (OSI) for varying degree of stenosis is quantified. The validated transitional shear stress transport (SST) k-ω model used in the present investigation is the best suited Reynolds averaged Navier-Stokes turbulence model to capture the turbulent transition. The arterial wall is assumed to be rigid and the dynamic curvature effect due to myocardial contraction on the blood flow has been neglected. Results Our observations shows that for stenosis 50% and above, the WSSavg, WSSmax and OSI calculated using turbulence model deviates from laminar by more than 10% and the flow disturbances seems to significantly increase only after 70% stenosis. Our model shows reliability and completely validated. Conclusions Blood flow through stenosed coronary arteries seems to be turbulent in nature for area stenosis above 70% and the transition to turbulent flow begins from 50% stenosis. PMID:27280084

  7. Numerical analysis of the effect of turbulence transition on the hemodynamic parameters in human coronary arteries.

    PubMed

    Mahalingam, Arun; Gawandalkar, Udhav Ulhas; Kini, Girish; Buradi, Abdulrajak; Araki, Tadashi; Ikeda, Nobutaka; Nicolaides, Andrew; Laird, John R; Saba, Luca; Suri, Jasjit S

    2016-06-01

    Local hemodynamics plays an important role in atherogenesis and the progression of coronary atherosclerosis disease (CAD). The primary biological effect due to blood turbulence is the change in wall shear stress (WSS) on the endothelial cell membrane, while the local oscillatory nature of the blood flow affects the physiological changes in the coronary artery. In coronary arteries, the blood flow Reynolds number ranges from few tens to several hundreds and hence it is generally assumed to be laminar while calculating the WSS calculations. However, the pulsatile blood flow through coronary arteries under stenotic condition could result in transition from laminar to turbulent flow condition. In the present work, the onset of turbulent transition during pulsatile flow through coronary arteries for varying degree of stenosis (i.e., 0%, 30%, 50% and 70%) is quantitatively analyzed by calculating the turbulent parameters distal to the stenosis. Also, the effect of turbulence transition on hemodynamic parameters such as WSS and oscillatory shear index (OSI) for varying degree of stenosis is quantified. The validated transitional shear stress transport (SST) k-ω model used in the present investigation is the best suited Reynolds averaged Navier-Stokes turbulence model to capture the turbulent transition. The arterial wall is assumed to be rigid and the dynamic curvature effect due to myocardial contraction on the blood flow has been neglected. Our observations shows that for stenosis 50% and above, the WSSavg, WSSmax and OSI calculated using turbulence model deviates from laminar by more than 10% and the flow disturbances seems to significantly increase only after 70% stenosis. Our model shows reliability and completely validated. Blood flow through stenosed coronary arteries seems to be turbulent in nature for area stenosis above 70% and the transition to turbulent flow begins from 50% stenosis.

  8. [Prediction of human orthostatic tolerance by changes in arterial and venous hemodynamics in the microgravity environment].

    PubMed

    Kotovskaia, A R; Fomin, G A

    2013-01-01

    The authors intentionally present exclusively the results of their recent studies of arterial and venous hemodynamics as predictors of human orthostatic tolerance (OT) during space flight and on return to Earth. There is a sufficient demonstration of the in-flight OT predictability by arterial hemodynamic reactions to LBNP and venous hemodynamic changes in response to the lower extremities occlusion. Three levels of cerebral blood flow deficits in the course of the lower body negative pressure test (LBNP) performed in microgravity were first defined. The authors offer quantitative arguments for the dependence of cerebral flow deficit on the degree of LBNP tolerance degradation. Patterns of arterial hemodynamics during LBNP were used successfully to diagnose the actual orthostatic tolerance and also to follow its trend as flight extended, which attests to the predictability of OT change in an individual cosmonaut on space flight. Occlusion plethysmography of legs revealed three levels of response of the most informative venous parameters (capacity, distensibility and rate of filling) correlating with severity of OT degradation.

  9. A dimensionless parameter for classifying hemodynamics in intracranial

    NASA Astrophysics Data System (ADS)

    Asgharzadeh, Hafez; Borazjani, Iman

    2015-11-01

    Rupture of an intracranial aneurysm (IA) is a disease with high rates of mortality. Given the risk associated with the aneurysm surgery, quantifying the likelihood of aneurysm rupture is essential. There are many risk factors that could be implicated in the rupture of an aneurysm. However, the most important factors correlated to the IA rupture are hemodynamic factors such as wall shear stress (WSS) and oscillatory shear index (OSI) which are affected by the IA flows. Here, we carry out three-dimensional high resolution simulations on representative IA models with simple geometries to test a dimensionless number (first proposed by Le et al., ASME J Biomech Eng, 2010), denoted as An number, to classify the flow mode. An number is defined as the ratio of the time takes the parent artery flow transports across the IA neck to the time required for vortex ring formation. Based on the definition, the flow mode is vortex if An>1 and it is cavity if An<1. We show that the specific definition of Le et al. works for sidewall but needs to be modified for bifurcation aneurysms. In addition, we show that this classification works on three-dimensional geometries reconstructed from three-dimensional rotational angiography of human subjects. Furthermore, we verify the correlation of IA flow mode and WSS/OSI on the human subject IA. This work was supported partly by the NIH grant R03EB014860, and the computational resources were partly provided by CCR at UB. We thank Prof. Hui Meng and Dr. Jianping Xiang for providing us the database of aneurysms and helpful discussions.

  10. Joint state and parameter estimation of the hemodynamic model by particle smoother expectation maximization method

    NASA Astrophysics Data System (ADS)

    Aslan, Serdar; Taylan Cemgil, Ali; Akın, Ata

    2016-08-01

    Objective. In this paper, we aimed for the robust estimation of the parameters and states of the hemodynamic model by using blood oxygen level dependent signal. Approach. In the fMRI literature, there are only a few successful methods that are able to make a joint estimation of the states and parameters of the hemodynamic model. In this paper, we implemented a maximum likelihood based method called the particle smoother expectation maximization (PSEM) algorithm for the joint state and parameter estimation. Main results. Former sequential Monte Carlo methods were only reliable in the hemodynamic state estimates. They were claimed to outperform the local linearization (LL) filter and the extended Kalman filter (EKF). The PSEM algorithm is compared with the most successful method called square-root cubature Kalman smoother (SCKS) for both state and parameter estimation. SCKS was found to be better than the dynamic expectation maximization (DEM) algorithm, which was shown to be a better estimator than EKF, LL and particle filters. Significance. PSEM was more accurate than SCKS for both the state and the parameter estimation. Hence, PSEM seems to be the most accurate method for the system identification and state estimation for the hemodynamic model inversion literature. This paper do not compare its results with Tikhonov-regularized Newton—CKF (TNF-CKF), a recent robust method which works in filtering sense.

  11. [Wall motion abnormalities and hemodynamic parameters in patients with left bundle branch block during exercise echocardiography].

    PubMed

    Dupliakov, D V; Vozhdaeva, Z I; Sysuenkova, E V; Zemlianova, M E; Lotina, A S; Goleva, S V; Svetlakova, A P; Khokhlunov, S M

    2011-01-01

    Study aim was to investigate dynamics of local contractility and hemodynamic parameters during exercise stress echocardiography (EEcho) in patients with left bundle branch block (LBBB). We examined 23 patients (15 men, 8 women) aged 48-65 years (mean age 53.9+/-8.1 years). Bicycle EEcho was accomplished according to standard protocol. Patients without clinical signs of ischemic heart disease (n=11) comprised group 1, patients after myocardial infarction (n=12) - group 2 (subgroup 2A - with negative test result, subgroup 2B - with worsening of local left ventricular contractility during EEcho). At baseline group 1 patients had significantly better hemodynamic parameters (ejection fraction - EF, left ventricular end diastolic volume - LVEDV) and no abnormalities of local contractility. Exercise tolerance was also the highest in this group. Insignificant worsening of postexercise EF occurred in patients of subgroup 2B (from 46+/-10.5 to 44,2+/-9.4%). In group 1 EF significantly increased (from 56.8+/-10.5% to 64.7+/-15.4%, <0.05), in subgroup 2A tendency to EF increase up to 48.7+/-9.9% was registered. Lowering of local contractility abnormalities index was noted also only in patients of subgroup 2B (from 1.54+/-0.4 to 2.17+/-0.37 (p<0.01). LVEDV compared with initial values tended to decrease in both groups (however differences between groups were not significant). Positive echocardiographic response was associated with significant changes of transmitral blood flow. Angiographically clean coronary arteries were found in 8 of 10 patients in group 1. Six group 2 patients with history of typical clinical picture of angina and myocardial infarction) had multivessel lesions in coronary vascular bed. EEcho result was positive in 5 of 6 group 2 patients. Thus EEcho possesses high potential for diagnosis of coronary atherosclerosis in patients with LBBB. This allows recommending it as a first line method in patients with this pathology.

  12. Clitoral hemodynamic changes after a topical application of alprostadil.

    PubMed

    Becher, E F; Bechara, A; Casabe, A

    2001-01-01

    We performed duplex ultrasonography of the clitoris to assess the local hemodynamic changes after a topical application of alprostadil. Color duplex ultrasonography was used to evaluate 18 women before and after the application of 1 g of 0.2% alprostadil gel. The peak systolic velocity and end diastolic velocity showed a statistically significant difference after the application. All women showed labial and clitoral engorgement, 72% reported a pleasant sensation of warmth, and no systemic side effects were found. These findings are similar to the values reported after sexual stimulation, indicating that topical vasoactive drugs might help in the differential diagnosis of the vascular component of female sexual dysfunction.

  13. [Changes of renal hemodynamics in dogs with endotoxemic shock].

    PubMed

    Yang, Rongli; Wang, Xiaoting; Liu, Sibo; Liu, Dawei

    2014-01-21

    To explore the changes of renal hemodynamic in dogs with endotoxemic shock (ES) and their potential roles in acute kidney injury (AKI). Canine endotoxic shock model was induced by an infusion of lipopolysaccharide of Escherichia coli through pulmonary artery catheter (PAC). Systemic hemodynamics and left renal blood flow (RBF) was monitored by PAC, pulse index continuous cardiac output (PiCCO) and ultrasonic blood flow meter. Blood and urine specimens were harvested timely for blood gas analysis, renal function tests and biochemical detection. Hemodynamics: CO and RBF fluctuated widely but without any significance (P > 0.05). The values of mean arterial pressure (MAP), systemic vascular resistance (SVR), renal vascular resistance (RVR) and 2-hour urine volume significantly decreased (all P < 0.05) while extravascular lung water (EVLW) increased markedly (P < 0.05). Renal function: There was a drop in CCr, urine osmotic pressure and an elevation in SCr and NAG. RBF was correlated positively with CO (R(2) = 0.630, P = 0.001) .However, it had no correlation with MAP (R(2) = 0.009, P = 0.758) . CCr was correlated positively with MAP (R(2) = 0.415, P = 0.003) . However, it had no correlation with RBF or CO (P > 0.05 ). The auto-regulation curve of GFR had a shift to the right. RBF is positively correlated with cardiac output in endotoxin shock. Renal pressure perfusion may decrease obviously without any noticeable change of renal flow perfusion. The shift of renal auto-regulation under pressure perfusion occurs at the early stage of septic shock.

  14. The Acute Impact of Smoking One Cigarette on Cardiac Hemodynamic Parameters

    PubMed Central

    Farha, Khalid Abou; AbouFarha, Ramy; Bolt, Marc

    2011-01-01

    Background The acute impact of tobacco smoking on the cardiac hemodynamic parameters and its pathological implication in the process of arterial atherosclerosis need further exploration. This investigation was purposed to assess the acute impact of tobacco smoke on blood pressure and cardiac hemodynamic parameters. Methods Using an Ultrasonic Cardiac Output Monitor, and DINAMAP Pro 400 Series V2 blood pressure monitor, several cardiac hemodynamic parameters and the blood pressure were assessed in 14 smokers, 11 females and 3 males, at 2 time points, before and after smoking of one cigarette. Data, in terms of ratio of the means and 95% confidence interval were analyzed using ANOVA. Results Single-subject design in which the subject has served as his/her own control has been used. Tobacco smoking led to statistically significant acute increase in the means of all hemodynamic parameters, except for heart rate in female subjects, as compared to the means obtained before smoking. Conclusions Cigarette smoking induces acute non-physiologic alteration in cardiac outflow forces, exposing the aortic valve and arch to mechanical injury that might be implicated in initiating and promoting the process of aortic arch atherosclerosis and associated pathological lesions.

  15. [Hemodynamic changes induced by positive pressure capnothorax during thoracoscopic thymectomy].

    PubMed

    Tomescu, Dana; Grigorescu, B; Nitulescu, R; Tomulescu, V; Popescu, I; Tulbure, D

    2007-01-01

    Low-flow insufflation of CO2 into the thorax helps the surgeon by increasing the surgical field during thoracoscopy, but older studies performed on animals (pigs and dogs) showed that positive pressure capnothorax had negative hemodynamic impact on animals and strongly recommended against using it on humans. We included in our study 24 ASA I-II myasthenic patients (20 females and 4 males) age 29 yo (+/- 10.2) weight 62.8 kg (+/- 10.6) whose thymuses were surgically removed by thoracoscopy. Using thoracic electrical bioimpedance (TEB) we assessed noninvasively cardiac index (CI) stroke index (SI) systemic stroke vascular resistance index (SSVRI) and end diastolic index (EDI). Well known for its hemodynamic stability we chose sevoflurane for induction and maintenance of anesthesia (VIMA). According to Copenhagen scale, adding minimal iv dose of fentanyl (3 mcg/kg) to sevoflurane induction, allowed us to endobronchial intubate in good and excellent conditions. During anesthesia almost all measured parameters (CI, SI, MAP, EDI) recorded statistically significant decrease but with minimal clinical significance. Thus, the maximal drop was measured during application of 10 mm Hg capnothorax: CI and SI dropped by 1.16 1/min/m2 (19%) (p = 0.02) and respectively 16.58 ml/m2 (21%) (p = 0.001). Thereby we are applying low-flow positive pressure insufflation of CO2 into the thorax, to almost all thoracoscopies performed in our clinic.

  16. Hemodynamic Changes following Aortic Valve Bypass: A Mathematical Approach

    PubMed Central

    Benevento, Emilia; Djebbari, Abdelghani; Keshavarz-Motamed, Zahra; Cecere, Renzo; Kadem, Lyes

    2015-01-01

    Aortic valve bypass (AVB) has been shown to be a viable solution for patients with severe aortic stenosis (AS). Under this circumstance, the left ventricle (LV) has a double outlet. The objective was to develop a mathematical model capable of evaluating the hemodynamic performance following the AVB surgery. A mathematical model that captures the interaction between LV, AS, arterial system, and AVB was developed. This model uses a limited number of parameters that all can be non-invasively measured using patient data. The model was validated using in vivo data from the literature. The model was used to determine the effect of different AVB and AS configurations on flow proportion and pressure of the aortic valve and the AVB. Results showed that the AVB leads to a significant reduction in transvalvular pressure gradient. The percentage of flow through the AVB can range from 55.47% to 69.43% following AVB with a severe AS. LV stroke work was also significantly reduced following the AVB surgery and reached a value of around 1.2 J for several AS severities. Findings of this study suggest: 1) the AVB leads to a significant reduction in transvalvular pressure gradients; 2) flow distribution between the AS and the AVB is significantly affected by the conduit valve size; 3) the AVB leads to a significant reduction in LV stroke work; and 4) hemodynamic performance variations can be estimated using the model. PMID:25881082

  17. Cerebral hemodynamic changes in stroke during sleep-disordered breathing.

    PubMed

    Pizza, Fabio; Biallas, Martin; Kallweit, Ulf; Wolf, Martin; Bassetti, Claudio L

    2012-07-01

    Sleep-disordered breathing (SDB) negatively impacts stroke outcome. Near-infrared spectroscopy showed the acute cerebral hemodynamic effects of SDB. Eleven patients (7 men, age 61±13 years) with acute/subacute middle cerebral artery stroke (National Institutes of Health Stroke Scale score 10±7) and SDB (apnea-hypopnea index 32±28/hour) were assessed with nocturnal polysomnography and bilateral near-infrared spectroscopy recording. Cerebral oxygenation and hemoglobin concentration changes during obstructive and central apneas were analyzed. During SDB, near-infrared spectroscopy showed asymmetrical patterns of cerebral oxygenation and hemoglobin concentrations with changes significantly larger on the unaffected compared with the affected hemisphere. Brain tissue hypoxia was more severe during obstructive compared with central apneas. Profound cerebral deoxygenation effects of SDB occurred in acute/subacute stroke. These changes may contribute to poor outcome, arising in the possibility of a potential benefit of SDB treatment in stroke management.

  18. Analysis of the postoperative hemodynamic changes in varicose vein surgery using air plethysmography.

    PubMed

    Park, Ui-Jun; Yun, Woo-Sung; Lee, Kyung-Bok; Rho, Young-Nam; Kim, Young-Wook; Joh, Jin-Hyun; Kim, Dong-Ik

    2010-03-01

    This study used air plethysmographic parameters to evaluate the changes in venous hemodynamics after the surgical treatment of primary varicose veins. We retrospectively analyzed 1756 limbs of 1620 patients who had undergone surgery for great saphenous vein (GSV) reflux from January 1996 to June 2009 at Samsung Medical Center. Venous hemodynamic changes were evaluated by performing air plethysmography preoperatively and 1 month postoperatively and assessing the venous volume (VV), the venous filling index (VFI), the residual volume fraction (RVF), and the ejection fraction (EF). Preoperatively, median (interquartile range) values were VV, 121.6 (94.7-160.6) mL; VFI, 4.8 (2.9-7.6) mL/s; RVF, 40.6% (29.7%-50.0%); and EF, 53.5% (44.3%-64.1%). Postoperatively, the median (interquartile range) values were VV, 90.6 (69.1-116.8) mL; VFI, 1.4 (0.9-1.9) mL/s; RVF, 28.4% (17.5%-38.7%); and EF, 65.2% (54.5%-77.2%). VV, VFI, and RVF were reduced 25.2%, 71.5%, and 29.9%, respectively; EF was increased 20.3%. The results were significant for all four variables (P < .001). We compared the degree of hemodynamic changes according to the treatment modalities: the high ligation and stripping group , 1578 cases; the GSV valvuloplasty group, 124 cases; and the VNUS group (VNUS Medical Technologies Inc, San Jose, CA), 54 cases. The reduction of the VV, VFI, and RVF was greater in the GSV stripping group and in the VNUS group than in the valvuloplasty group (P < .001), yet no difference was noted in the EF increase among the surgical modalities (P = .157). Our results show that the venous hemodynamic parameters of primary varicose veins were improved after surgical treatment.

  19. Hemodynamic changes in post-suspension rats during gradual hemorrhage

    NASA Astrophysics Data System (ADS)

    Vinogradova, O. L.; Borovik, A. S.; Tsvirkoun, D. V.; Tarasova, O. S.

    2005-08-01

    In urethane-anasthetized rats the effects of 2-week tail suspension upon the hemodynamic changes during simulated orthostatism and during loss of blood were studied. Baseline values of mean arterial pressure (MAP) and pulse interval (PI) did not differ in cage control (C) and post-suspension rats (TS). In both groups 45o head-up tilt resulted in prominent decline of MAP. In C group this effect was followed by the compensatory phase, which was virtually lost in TS group. No significant postural changes of PI were observed. Gradual hemorrhage (30% blood loss during 30 min) resulted in similar MAP drop in C and TS (up to 40% of baseline level). Along with that, PI increase was less prominent in TS (25%) compared to C (60%) indicating higher resistance of the heart to hypovolemia after suspension.

  20. Hemodynamic changes by drug interaction of adrenaline with chlorpromazine.

    PubMed

    Higuchi, Hitoshi; Yabuki, Akiko; Ishii-Maruhama, Minako; Tomoyasu, Yumiko; Maeda, Shigeru; Miyawaki, Takuya

    2014-01-01

    Adrenaline (epinephrine) is included in dental local anesthesia for the purpose of vasoconstriction. In Japan, adrenaline is contraindicated for use in patients receiving antipsychotic therapy, because the combination of adrenaline and an antipsychotic is considered to cause severe hypotension; however, there is insufficient evidence supporting this claim. The purpose of the present study was to clarify the changes in hemodynamics caused by drug interaction between adrenaline and an antipsychotic and to evaluate the safety of the combined use of adrenaline and an antipsychotic in an animal study. Male Sprague-Dawley rats were anesthetized with sodium pentobarbital. A catheter was inserted into the femoral artery to measure blood pressure and pulse rate. Rats were pretreated by intraperitoneal injection of chlorpromazine or chlorpromazine and propranolol, and after 20 minutes, saline or 1 of 3 different doses of adrenaline was administered by intraperitoneal injection. Changes in the ratio of mean arterial blood pressure and pulse rate were measured after the injection of adrenaline. Significant hypotension and tachycardia were observed after the injection of adrenaline in the chlorpromazine-pretreated rats. These effects were in a dose-dependent manner, and 100 μg/kg adrenaline induced significant hemodynamic changes. Furthermore, in the chlorpromazine and propranolol-pretreated rats, modest hypertension was induced by adrenaline, but hypotension and tachycardia were not significantly shown. Hypotension was caused by a drug interaction between adrenaline and chlorpromazine through the activation of the β-adrenergic receptor and showed a dose-dependent effect. Low-dose adrenaline similar to what might be used in human dental treatment did not result in a significant homodynamic change.

  1. Hemodynamic Changes by Drug Interaction of Adrenaline With Chlorpromazine

    PubMed Central

    Higuchi, Hitoshi; Yabuki, Akiko; Ishii-Maruhama, Minako; Tomoyasu, Yumiko; Maeda, Shigeru; Miyawaki, Takuya

    2014-01-01

    Adrenaline (epinephrine) is included in dental local anesthesia for the purpose of vasoconstriction. In Japan, adrenaline is contraindicated for use in patients receiving antipsychotic therapy, because the combination of adrenaline and an antipsychotic is considered to cause severe hypotension; however, there is insufficient evidence supporting this claim. The purpose of the present study was to clarify the changes in hemodynamics caused by drug interaction between adrenaline and an antipsychotic and to evaluate the safety of the combined use of adrenaline and an antipsychotic in an animal study. Male Sprague-Dawley rats were anesthetized with sodium pentobarbital. A catheter was inserted into the femoral artery to measure blood pressure and pulse rate. Rats were pretreated by intraperitoneal injection of chlorpromazine or chlorpromazine and propranolol, and after 20 minutes, saline or 1 of 3 different doses of adrenaline was administered by intraperitoneal injection. Changes in the ratio of mean arterial blood pressure and pulse rate were measured after the injection of adrenaline. Significant hypotension and tachycardia were observed after the injection of adrenaline in the chlorpromazine-pretreated rats. These effects were in a dose-dependent manner, and 100 μg/kg adrenaline induced significant hemodynamic changes. Furthermore, in the chlorpromazine and propranolol–pretreated rats, modest hypertension was induced by adrenaline, but hypotension and tachycardia were not significantly shown. Hypotension was caused by a drug interaction between adrenaline and chlorpromazine through the activation of the β-adrenergic receptor and showed a dose-dependent effect. Low-dose adrenaline similar to what might be used in human dental treatment did not result in a significant homodynamic change. PMID:25517550

  2. Helical CT study of cerebral perfusion and related hemodynamic parameters

    NASA Astrophysics Data System (ADS)

    Cenic, Aleksa; Lee, Ting-Yim; Craen, Rosemary A.; Gelb, Adrian W.

    1997-05-01

    A convenient method for assessing cerebral perfusion and related functional parameters has been developed using a third generation slip-ring CT scanner. Dynamic contrast- enhanced scanning at the same level was employed to image the cerebral circulation at the rate of 1 image per second. Using data acquired with this non-helical mode of scanning, we have developed a method for the simultaneous in-vivo determination of cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time (MTT). These measurements are given in the same physiological units as positron emission tomography. In order to obtain accurate measurements of these parameters, methods were also developed to correct for recirculation and partial volume averaging in imaging small blood vessels. We have used 6 New Zealand white rabbits in our studies. For each rabbit, up to 3 CT measurements of CBF, CBV, and MTT were made at normocapnia under isoflurane anesthesia. Coronal sections through the brain were imaged while simultaneously imaging either a brain artery or the ear artery. Images were acquired for 1 minute as Isovue 300 was injected intravenously. In the acquired CT images, regions of interest in brain parenchyma and an artery were drawn. For each region of interest, the mean CT number in pre-contrast images was subtracted from the mean in post-contrast images to calculate the contrast concentration curves for the brain regions Q(t) and the arterial region Ca(t). Using a robust deconvolution method, the MTT was determined. CBV was then determined from the ratio of the areas of Q(t) and Ca(t). Finally, CBF was calculated from the Central Volume Principle. The mean regional CBF, CBV and MTT values were 73.3 +/- 5.1 ml/min/100g, 1.93 +/- 0.12 ml/100g and 1.80 +/- 0.18 s respectively. IN order to validate our CT CBF measurements, we also measured CBF using the well- established technique of microspheres with each CT study. The feasibility of our CT method to measure CBF accurately was

  3. A computer-based matrix for rapid calculation of pulmonary hemodynamic parameters in congenital heart disease

    PubMed Central

    Lopes, Antonio Augusto; dos Anjos Miranda, Rogério; Gonçalves, Rilvani Cavalcante; Thomaz, Ana Maria

    2009-01-01

    BACKGROUND: In patients with congenital heart disease undergoing cardiac catheterization for hemodynamic purposes, parameter estimation by the indirect Fick method using a single predicted value of oxygen consumption has been a matter of criticism. OBJECTIVE: We developed a computer-based routine for rapid estimation of replicate hemodynamic parameters using multiple predicted values of oxygen consumption. MATERIALS AND METHODS: Using Microsoft® Excel facilities, we constructed a matrix containing 5 models (equations) for prediction of oxygen consumption, and all additional formulas needed to obtain replicate estimates of hemodynamic parameters. RESULTS: By entering data from 65 patients with ventricular septal defects, aged 1 month to 8 years, it was possible to obtain multiple predictions for oxygen consumption, with clear between-age groups (P <.001) and between-methods (P <.001) differences. Using these predictions in the individual patient, it was possible to obtain the upper and lower limits of a likely range for any given parameter, which made estimation more realistic. CONCLUSION: The organized matrix allows for rapid obtainment of replicate parameter estimates, without error due to exhaustive calculations. PMID:19641642

  4. Applying dynamic parameters to predict hemodynamic response to volume expansion in spontaneously breathing patients with septic shock

    PubMed Central

    Lanspa, Michael J.; Grissom, Colin K.; Hirshberg, Eliotte L.; Jones, Jason P.; Brown, Samuel M.

    2013-01-01

    Background Volume expansion is a mainstay of therapy in septic shock, although its effect is difficult to predict using conventional measurements. Dynamic parameters, which vary with respiratory changes, appear to predict hemodynamic response to fluid challenge in mechanically ventilated, paralyzed patients. Whether they predict response in patients who are free from mechanical ventilation is unknown. We hypothesized that dynamic parameters would be predictive in patients not receiving mechanical ventilation. Methods This is a prospective, observational, pilot study. Patients with early septic shock and who were not receiving mechanical ventilation received 10 ml/kg volume expansion (VE) at their treating physician's discretion after initial resuscitation in the emergency department. We used transthoracic echocardiography to measure vena cava collapsibility index (VCCI) and aortic velocity variation (AoVV) prior to VE. We used a pulse contour analysis device to measure stroke volume variation (SVV). Cardiac index was measured immediately before and after VE using transthoracic echocardiography. Hemodynamic response was defined as an increase in cardiac index ≥ 15%. Results 14 patients received VE, 5 of which demonstrated a hemodynamic response. VCCI and SVV were predictive (Area under curve = 0.83, 0.92, respectively). Optimal thresholds were calculated: VCCI ≥ 15% (Positive predictive value, PPV 62%, negative predictive value, NPV 100%, p = 0.03); SVV ≥ 17% (PPV 100%, NPV 82%, p = 0.03). AoVV was not predictive. Conclusions VCCI and SVV predict hemodynamic response to fluid challenge patients with septic shock who are not mechanically ventilated. Optimal thresholds differ from those described in mechanically ventilated patients. PMID:23324885

  5. Periodic leg movements during sleep and cerebral hemodynamic changes detected by NIRS.

    PubMed

    Pizza, Fabio; Biallas, Martin; Wolf, Martin; Valko, Philipp O; Bassetti, Claudio L

    2009-07-01

    Periodic leg movements during sleep (PLMS) have been shown to be associated with changes in autonomic and hemispheric activities. Near infrared spectroscopy (NIRS) assesses hemodynamic changes linked to hemispheric/cortical activity. We applied NIRS to test whether cerebral hemodynamic alterations accompany PLMS. Three PLMS patients underwent nocturnal polysomnography coupled with cerebral NIRS. EEG correlates of PLMS were scored and NIRS data were analysed for the identification of correspondent hemodynamic changes. PLMS were constantly associated with cerebral hemodynamic fluctuations that showed greater amplitude when associated to changes in EEG and were present also in absence of any visually detectable arousal or A phase in the EEG. This is the first study documenting cerebral hemodynamic changes linked to PLMS. The clinical relevance of these observations remains to be determined.

  6. [Study of the effect of colloidal solution of silver nanoparticles on parameters of cardio- and hemo-dynamics in rabbits].

    PubMed

    Pryskoka, A O

    2014-01-01

    Metal nanoparticles and silver nanoparticles in particular are extensively studied recently considering their prominent antimicrobial properties. Nevertheless, their toxicity aspects and probable side effects remain not well studied. In this article the results of study of the influence of silver nanoparticles onto a cardiovascular system in an in vivo experiment were provided, changes in parameters of cardio- and hemodynamics were defined, and the principles of such influence were identified. Dose-dependent effect of these nanoparticles was established when administered in dose of 4.3 mg/kg three times and 20 mg/kg once.

  7. Effects of AV-delay optimization on hemodynamic parameters in patients with VDD pacemakers.

    PubMed

    Krychtiuk, Konstantin A; Nürnberg, Michael; Volker, Romana; Pachinger, Linda; Jarai, Rudolf; Freynhofer, Matthias K; Wojta, Johann; Huber, Kurt; Weiss, Thomas W

    2014-05-01

    Atrioventricular (AV) delay optimization improves hemodynamics and clinical parameters in patients treated with cardiac resynchronization therapy and dual-chamber-pacemakers (PM). However, data on optimizing AV delay in patients treated with VDD-PMs are scarce. We, therefore, investigated the acute and chronic effects of AV delay optimization on hemodynamics in patients treated with VDD-PMs due to AV-conduction disturbances. In this prospective, single-center interventional trial, we included 64 patients (38 men, 26 women, median age: 77 (70-82) years) with implanted VDD-PM. AV-delay optimization was performed using a formula based on the surface electrocardiogram (ECG). Hemodynamic parameters (stroke volume (SV), cardiac output (CO), heart rate (HR), and blood pressure (BP)) were measured at baseline and follow-up after 3 months using impedance cardiography. Using an ECG formula for AV-delay optimization, the AV interval was decreased from 180 (180-180) to 75 (75-100) ms. At baseline, AV-delay optimization led to a significant increase of both SV (71.3 ± 15.8 vs. 55.3 ± 12.7 ml, p < 0.001, for optimized AV delay vs. nominal AV interval, respectively) and CO (5.1 ± 1.4 vs. 3.9 ± 1.0 l/min, p < 0.001), while HR and BP remained unchanged. At follow-up, the improvement in CO remained stable (4.9 ± 1.3 l/min, p = 0.09), while SV slightly, but significantly, decreased (to 65.1 ± 17.6, p < 0.01). AV-delay optimization in patients treated with VDD-PMs exhibits immediate beneficial effects on hemodynamic parameters that are sustained for 3 months.

  8. Hemodynamic changes in a rat parietal cortex after endothelin-1-induced middle cerebral artery occlusion monitored by optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Liu, Jian; Ma, Yushu; Dou, Shidan; Wang, Yi; La, Dongsheng; Liu, Jianghong; Ma, Zhenhe

    2016-07-01

    A blockage of the middle cerebral artery (MCA) on the cortical branch will seriously affect the blood supply of the cerebral cortex. Real-time monitoring of MCA hemodynamic parameters is critical for therapy and rehabilitation. Optical coherence tomography (OCT) is a powerful imaging modality that can produce not only structural images but also functional information on the tissue. We use OCT to detect hemodynamic changes after MCA branch occlusion. We injected a selected dose of endothelin-1 (ET-1) at a depth of 1 mm near the MCA and let the blood vessels follow a process first of occlusion and then of slow reperfusion as realistically as possible to simulate local cerebral ischemia. During this period, we used optical microangiography and Doppler OCT to obtain multiple hemodynamic MCA parameters. The change trend of these parameters from before to after ET-1 injection clearly reflects the dynamic regularity of the MCA. These results show the mechanism of the cerebral ischemia-reperfusion process after a transient middle cerebral artery occlusion and confirm that OCT can be used to monitor hemodynamic parameters.

  9. Partial hepatectomy hemodynamics changes: Experimental data explained by closed-loop lumped modeling.

    PubMed

    Audebert, Chloe; Bekheit, Mohamed; Bucur, Petru; Vibert, Eric; Vignon-Clementel, Irene E

    2017-01-04

    The liver function may be degraded after partial liver ablation surgery. Adverse liver hemodynamics have been shown to be associated to liver failure. The link between these hemodynamics changes and ablation size is however poorly understood. This article proposes to explain with a closed-loop lumped model the hemodynamics changes observed during twelve surgeries in pigs. The portal venous tree is modeled with a pressure-dependent variable resistor. The variables measured, before liver ablation, are used to tune the model parameters. Then, the liver partial ablation is simulated with the model and the simulated pressures and flows are compared with post-operative measurements. Fluid infusion and blood losses occur during the surgery. The closed-loop model presented accounts for these blood volume changes. Moreover, the impact of blood volume changes and the liver lobe mass estimations on the simulated variables is studied. The typical increase of portal pressure, increase of liver pressure loss, slight decrease of portal flow and major decrease in arterial flow are quantitatively captured by the model for a 75% hepatectomy. It appears that the 75% decrease in hepatic arterial flow can be explained by the resistance increase induced by the surgery, and that no hepatic arterial buffer response (HABR) mechanism is needed to account for this change. The different post-operative states, observed in experiments, are reproduced with the proposed model. Thus, an explanation for inter-subjects post-operative variability is proposed. The presented framework can easily be adapted to other species circulations and to different pathologies for clinical hepatic applications.

  10. Changes in vitelline and utero-placental hemodynamics: implications for cardiovascular development

    PubMed Central

    Linask, Kersti K.; Han, Mingda; Bravo-Valenzuela, Nathalie J. M.

    2014-01-01

    Analyses of cardiovascular development have shown an important interplay between heart function, blood flow, and morphogenesis of heart structure during the formation of a four-chambered heart. It is known that changes in vitelline and placental blood flow seemingly contribute substantially to early cardiac hemodynamics. This suggests that in order to understand mammalian cardiac structure-hemodynamic functional relationships, blood flow from the extra-embryonic circulation needs to be taken into account and its possible impact on cardiogenesis defined. Previously published Doppler ultrasound analyses and data of utero-placental blood flow from human studies and those using the mouse model are compared to changes observed with environmental exposures that lead to cardiovascular anomalies. Use of current concepts and models related to mechanotransduction of blood flow and fluid forces may help in the future to better define the characteristics of normal and abnormal utero-placental blood flow and the changes in the biophysical parameters that may contribute to congenital heart defects. Evidence from multiple studies is discussed to provide a framework for future modeling of the impact of experimental changes in blood flow on the mouse heart during normal and abnormal cardiogenesis. PMID:25426076

  11. [Effects of phenibut on parameters of cerebral hemodynamics in swimmers with dysadaptation syndrome and various types of systemic hemodynamics].

    PubMed

    Likhodeeva, V A; Spasov, A A; Isupov, I B; Mandrikov, V B

    2010-08-01

    Administration of phenibut (0.25 g) during 4 weeks as a means of rehabilitation promoted optimization of the biochemical status and cerebral blood circulation in swimmers with various types of systemic hemodynamics, which were examined 20 minutes after warm-up.

  12. Bedside calculation of hemodynamic parameters with a hand-held programmable calculator. Part I.: Choice of hemodynamic formulas.

    PubMed

    Laurent, M

    1980-01-01

    Currently used hemodynamic and oxygen transport formulas are reviewed in order to chose the shortest form compatible with an optimal clinical accuracy. Programming of hand held calculators with these selected equations spares steps available in the program memory. (Acta anaesth. belg., 1980, 31, 45-52).

  13. Effect of Music Therapy on Patients’ Anxiety and Hemodynamic Parameters During Coronary Angioplasty: A Randomized Controlled Trial

    PubMed Central

    Forooghy, Masoumeh; Mottahedian Tabrizi, Elaheh; Hajizadeh, Ebrahim; Pishgoo, Bahram

    2015-01-01

    Background: A cardiac catheterization laboratory can be a frightening environment and music can be a supportive source of environmental sound that stimulates and maintains relaxation. However, the results of studies are conflicting in this regard. Objectives: The aim of this study was to investigate the effect of music therapy on patients’ anxiety and hemodynamic parameters during percutaneous transluminal coronary angioplasty. Patients and Methods: This was a randomized controlled trial, conducted in the Catheterization Laboratory Unit of Baqiyatallah Hospital, in Tehran, Iran. A sample of 64 patients, who were planned to undergo coronary angioplasty, was recruited. Patients were randomly allocated to either the control or the experimental groups. In the experimental group, patients received a 20 to 40-minute music therapy intervention, consisting of light instrumental music albums by Johann Sebastian Bach and Mariko Makino. Patients in the control group received the routine care of the study setting, which consisted of no music therapy intervention. Study data were collected by a demographic questionnaire, the Spielberger’s State Anxiety Inventory, and a data sheet for documenting hemodynamic parameters. Chi-square, independent-samples t tests, paired-samples t-test and repeated measures analysis of variance were used to analyze the data. Results: Before the intervention, the study groups did not differ significantly in terms of anxiety level and hemodynamic parameters. Moreover, the differences between the two groups, regarding hemodynamic parameters, were not significant after the intervention (P > 0.05). However, the level of post-intervention anxiety in the experimental group was significantly lower than the control group (32.06 ± 8.57 and 38.97 ± 12.77, respectively; P = 0.014). Compared with the baseline readings, the level of anxiety in the control group did not change significantly after the study (41.91 ± 9.88 vs. 38.97 ± 12.77; P = 0

  14. Hemodynamic, biochemical and morphological changes induced by aminoguanidine in normal and septic sheep.

    PubMed

    Lorente, J A; Tejedor, C; Delgado, M A; Fernández-Segoviano, P; Jara, N; Tobalina, R; Rodríguez-Corcos, A; Moscoso, A; Esteban, A

    2000-11-01

    To define the acute hemodynamic, metabolic, and morphological changes induced by aminoguanidine, a selective iNOS inhibitor, in septic sheep. Prospective, nonrandomized animal study. Animal research facility in a University Hospital. Adult sheep, sedated and mechanically ventilated, were monitored with a pulmonary arterial catheter and an ultrasonic blood flow probe in the mesenteric artery, to measure the systemic (Q(TOT)I) and the mesenteric (Q(MES)I) blood flow indices, and an ileal tonometer. Four groups of sheep were studied: nonseptic, septic, nonseptic treated with aminoguanidine, and septic treated with aminoguanidine (100 mg kg(-1) h(-1)) (n = 6 for each group). Sepsis was induced by the intravenous administration of E. coli. Hemodynamic and biochemical parameters were measured during 300 min. Histological changes in the liver and small intestinal mucosa were analyzed at the end of the experiment. In nonseptic animals, aminoguanidine slightly increased mean systemic arterial pressure (MAP), decreased Q(TOT)I, and increased vascular resistance index (SVRI) and pulmonary vascular resistance index. Q(MEs)I did not change and Q(MES)I/Q(ToT)I increased. Aminoguanidine also induced intestinal intramucosal hypercarbia, hyperlactatemia, acidemia, hypoglycemia, and morphological signs indicative of tissue ischemia in the small intestinal mucosa. In septic sheep, aminoguanidine increased SVRI and MAP only at 4 h after the septic challenge and thereafter, and worsened gas exchange. In this model, exogenous administration of aminoguanidine induces beneficial hemodynamic effects 4 h after the septic challenge. In normal animals, however, aminoguanidine was associated with hypoglycemia, acidosis, hyperlactatemia, and intestinal mucosal ischemia.

  15. The impact of ocular hemodynamics and intracranial pressure on intraocular pressure during acute gravitational changes.

    PubMed

    Nelson, Emily S; Mulugeta, Lealem; Feola, Andrew; Raykin, Julia; Myers, Jerry G; Samuels, Brian C; Ethier, C Ross

    2017-08-01

    Exposure to microgravity causes a bulk fluid shift toward the head, with concomitant changes in blood volume/pressure, and intraocular pressure (IOP). These and other factors, such as intracranial pressure (ICP) changes, are suspected to be involved in the degradation of visual function and ocular anatomical changes exhibited by some astronauts. This is a significant health concern. Here, we describe a lumped-parameter numerical model to simulate volume/pressure alterations in the eye during gravitational changes. The model includes the effects of blood and aqueous humor dynamics, ICP, and IOP-dependent ocular compliance. It is formulated as a series of coupled differential equations and was validated against four existing data sets on parabolic flight, body inversion, and head-down tilt (HDT). The model accurately predicted acute IOP changes in parabolic flight and HDT, and was satisfactory for the more extreme case of inversion. The short-term response to the changing gravitational field was dominated by ocular blood pressures and compliance, while longer-term responses were more dependent on aqueous humor dynamics. ICP had a negligible effect on acute IOP changes. This relatively simple numerical model shows promising predictive capability. To extend the model to more chronic conditions, additional data on longer-term autoregulation of blood and aqueous humor dynamics are needed.NEW & NOTEWORTHY A significant percentage of astronauts present anatomical changes in the posterior eye tissues after spaceflight. Hypothesized increases in ocular blood volume and intracranial pressure (ICP) in space have been considered to be likely factors. In this work, we provide a novel numerical model of the eye that incorporates ocular hemodynamics, gravitational forces, and ICP changes. We find that changes in ocular hemodynamics govern the response of intraocular pressure during acute gravitational change. Copyright © 2017 the American Physiological Society.

  16. Use of Bioimpedance to Assess Changes in Hemodynamics During Acute Administration of CPAP

    PubMed Central

    Digby, Genevieve C.; Driver, Helen S.; Fitzpatrick, Michael; Ropchan, Glorianne; Parker, Christopher M.

    2011-01-01

    Background Attempts to investigate the mechanisms by which continuous positive airway pressure (CPAP) therapy improves heart function in patients with obstructive sleep apnea (OSA) have been limited by the lack of non-invasive methods to assess cardiac performance. We used transthoracic electrical bioimpedance (TEB) to assess acute hemodynamic changes including heart rate (HR), stroke volume (SV), cardiac output (CO) and cardiac index (CI) during PAP titration in (1) post-operative cardiac surgery patients, (2) patients with severe OSA, and (3) normal healthy volunteers. Methods Post-operative cardiac surgery patients were studied via TEB and pulmonary artery catheter (PAC) during acute titration of positive end-expiratory pressure (PEEP) while mechanically ventilated. Patients with severe OSA were studied non-invasively by TEB during acute CPAP titration in supine stage 2 sleep, and normal subjects while awake and recumbent. Results In post-operative cardiac surgery patients (n = 3), increasing PEEP to 18 cmH2O significantly reduced SV and CI relative to baseline. There was no difference between TEB and PAC in terms of ability to assess variations in hemodynamic parameters. In patients with severe OSA (n = 3), CPAP titration to optimal pressure to alleviate obstructive apneas reduced HR, SV, CO and CI significantly compared to without CPAP. In three healthy subjects, maximal tolerated CPAP reduced SV and CO significantly compared to baseline. Conclusions Acute administration of CPAP causes a decrease in CO and CI, apparently a consequence of a reduction in SV. TEB appears to be an accurate and reproducible non-invasive method of detecting changes in hemodynamics.

  17. Practical Steps for Applying a New Dynamic Model to Near-Infrared Spectroscopy Measurements of Hemodynamic Oscillations and Transient Changes

    PubMed Central

    Kainerstorfer, Jana M.; Sassaroli, Angelo; Hallacoglu, Bertan; Pierro, Michele L.; Fantini, Sergio

    2015-01-01

    Rationale and Objectives Perturbations in cerebral blood volume (CBV), blood flow (CBF), and metabolic rate of oxygen (CMRO2) lead to associated changes in tissue concentrations of oxy- and deoxy-hemoglobin (ΔO and ΔD), which can be measured by near-infrared spectroscopy (NIRS). A novel hemodynamic model has been introduced to relate physiological perturbations and measured quantities. We seek to use this model to determine functional traces of cbv(t) and cbf(t) − cmro2(t) from time-varying NIRS data, and cerebrovascular physiological parameters from oscillatory NIRS data (lowercase letters denote the relative changes in CBV, CBF, and CMRO2 with respect to baseline). Such a practical implementation of a quantitative hemodynamic model is an important step toward the clinical translation of NIRS. Materials and Methods In the time domain, we have simulated O(t) and D(t) traces induced by cerebral activation. In the frequency domain, we have performed a new analysis of frequency-resolved measurements of cerebral hemodynamic oscillations during a paced breathing paradigm. Results We have demonstrated that cbv(t) and cbf(t) − cmro2(t) can be reliably obtained from O(t) and D(t) using the model, and that the functional NIRS signals are delayed with respect to cbf(t) − cmro2(t) as a result of the blood transit time in the microvasculature. In the frequency domain, we have identified physiological parameters (e.g., blood transit time, cutoff frequency of autoregulation) that can be measured by frequency-resolved measurements of hemodynamic oscillations. Conclusions The ability to perform noninvasive measurements of cerebrovascular parameters has far-reaching clinical implications. Functional brain studies rely on measurements of CBV, CBF, and CMRO2, whereas the diagnosis and assessment of neurovascular disorders, traumatic brain injury, and stroke would benefit from measurements of local cerebral hemodynamics and autoregulation. PMID:24439332

  18. Near-infrared measurements of hemodynamic and oxygenation changes on the frontal cortex during breath holding, hyperventilation, and natural sleep

    NASA Astrophysics Data System (ADS)

    Noponen, Tommi E.; Kotilahti, Kalle; Toppila, Jussi; Nissila, Ilkka T.; Salmi, Tapani; Kajava, Timo T.; Katila, Toivo E.

    2003-07-01

    We have developed a frequency-domain near-infrared device suitable for physiological studies in human. In this work, a four-channel configuration of the instrument is applied to monitor hemodynamic and oxygenation changes in the frontal cortex of volunteers during different ventilation tasks. We use four different source-receiver separations (2, 3, 4, and 5 cm) and three wavelengths (760, 808, and 830 nm) to test the sensitivity of these parameters to cardiovascular and metabolic changes. Low-frequency oscillations (~ 0.02 Hz) and variations in heart rate during different ventilation tasks are investigated as well. We also study physiological changes during natural sleep using the frequency-domain instrument simultaneously with a polysomnography system containing a pulse oximeter. Our results indicate that hemodynamic and oxygenation changes in the frontal cortex during natural sleep can be detected using near-infrared measurements.

  19. The Impact of Hemodialysis and Arteriovenous Access Flow on Extracranial Hemodynamic Changes in End-Stage Renal Disease Patients

    PubMed Central

    2016-01-01

    In this study, we characterized cerebral blood flow changes by assessment of blood flow parameters in neck arteries using carotid duplex ultrasonography and predictive factors for these hemodynamic changes. Hemodynamic variables were measured before and during hemodialysis in 81 patients with an arteriovenous access in their arm. Hemodialysis produced significant lowering in peak systolic velocity and flow volume of neck arteries and calculated total cerebral blood flow (1,221.9 ± 344.9 [before hemodialysis] vs. 1,085.8 ± 319.2 [during hemodialysis], P < 0.001). Effects were greater in vessels on the same side as the arteriovenous access and these changes were influenced by arteriovenous access flow during hemodialysis, both in the CCA (r = -0.277, P = 0.015) and the VA (r = -0.239, P = 0.034). The change of total cerebral blood flow during hemodialysis was independently related with age, presence of diabetes, and systemic blood pressure. PMID:27478334

  20. Label-Free Determination of Hemodynamic Parameters in the Microcirculaton with Third Harmonic Generation Microscopy

    PubMed Central

    Dietzel, Steffen; Pircher, Joachim; Nekolla, A. Katharina; Gull, Mazhar; Brändli, André W.; Pohl, Ulrich; Rehberg, Markus

    2014-01-01

    Determination of blood flow velocity and related hemodynamic parameters is an important aspect of physiological studies which in many settings requires fluorescent labeling. Here we show that Third Harmonic Generation (THG) microscopy is a suitable tool for label-free intravital investigations of the microcirculation in widely-used physiological model systems. THG microscopy is a non-fluorescent multi-photon scanning technique combining the advantages of label-free imaging with restriction of signal generation to a focal spot. Blood flow was visualized and its velocity was measured in adult mouse cremaster muscle vessels, non-invasively in mouse ear vessels and in Xenopus tadpoles. In arterioles, THG line scanning allowed determination of the flow pulse velocity curve and hence the heart rate. By relocating the scan line we obtained velocity profiles through vessel diameters, allowing shear rate calculations. The cell free layer containing the glycocalyx was also visualized. Comparison of the current microscopic resolution with theoretical, diffraction limited resolution let us conclude that an about sixty-fold THG signal intensity increase may be possible with future improved optics, optimized for 1200–1300 nm excitation. THG microscopy is compatible with simultaneous two-photon excited fluorescence detection. It thus also provides the opportunity to determine important hemodynamic parameters in parallel to common fluorescent observations without additional label. PMID:24933027

  1. Hemodynamic Measurement Using Four-Dimensional Phase-Contrast MRI: Quantification of Hemodynamic Parameters and Clinical Applications.

    PubMed

    Ha, Hojin; Kim, Guk Bae; Kweon, Jihoon; Lee, Sang Joon; Kim, Young-Hak; Lee, Deok Hee; Yang, Dong Hyun; Kim, Namkug

    2016-01-01

    Recent improvements have been made to the use of time-resolved, three-dimensional phase-contrast (PC) magnetic resonance imaging (MRI), which is also named four-dimensional (4D) PC-MRI or 4D flow MRI, in the investigation of spatial and temporal variations in hemodynamic features in cardiovascular blood flow. The present article reviews the principle and analytical procedures of 4D PC-MRI. Various fluid dynamic biomarkers for possible clinical usage are also described, including wall shear stress, turbulent kinetic energy, and relative pressure. Lastly, this article provides an overview of the clinical applications of 4D PC-MRI in various cardiovascular regions.

  2. Hemodynamic Measurement Using Four-Dimensional Phase-Contrast MRI: Quantification of Hemodynamic Parameters and Clinical Applications

    PubMed Central

    Ha, Hojin; Kim, Guk Bae; Kweon, Jihoon; Lee, Sang Joon; Kim, Young-Hak; Lee, Deok Hee

    2016-01-01

    Recent improvements have been made to the use of time-resolved, three-dimensional phase-contrast (PC) magnetic resonance imaging (MRI), which is also named four-dimensional (4D) PC-MRI or 4D flow MRI, in the investigation of spatial and temporal variations in hemodynamic features in cardiovascular blood flow. The present article reviews the principle and analytical procedures of 4D PC-MRI. Various fluid dynamic biomarkers for possible clinical usage are also described, including wall shear stress, turbulent kinetic energy, and relative pressure. Lastly, this article provides an overview of the clinical applications of 4D PC-MRI in various cardiovascular regions. PMID:27390537

  3. Morphological and Hemodynamic Parameters for Middle Cerebral Artery Bifurcation Aneurysm Rupture Risk Assessment

    PubMed Central

    Qin, Hao; Yang, Qixia; Zhuang, Qiang; Long, Jianwu; Yang, Fan; Zhang, Hongqi

    2017-01-01

    Objective To investigate the morphological and hemodynamic parameters associated with middle cerebral artery (MCA)bifurcation aneurysm rupture. Methods A retrospective study of 67 consecutive patients was carried out based on 3D digital subtraction angiography data. Morphological and hemodynamic parameters including aneurysm size parameters (dome width, height, and perpendicular height), longest dimension from the aneurysm neck to the dome tip, neck width, aneurysm area, aspect ratio, Longest dimension from the aneurysm neck to the dome tip (Dmax) to dome width, and height-width, Bottleneck factor, as well as wall shear stress (WSS), low WSS area (LSA), percentage of LSA (LSA%) and energy loss (EL) were estimated. Parameters between ruptured and un-ruptured groups were analyzed. Receiver operating characteristics were generated to check prediction performance of all significant variables. Results Sixty-seven patients with MCA bifurcation aneurysm were included (31 unruptured, 36 ruptured). Dmax (p=0.008) was greater in ruptured group than that in un-ruptured group. D/W (p<0.001) and the percentage of the low WSS area (0.09±0.13 vs. 0.01±0.03, p<0.001) were also greater in the ruptured group. Moreover, the EL in ruptured group was higher than that in un-ruptured group (6.39±5.04 vs. 1.53±0.86, p<0.001). Multivariate regression analysis suggested D/W and EL were significant predictors of rupture of MCA bifurcation aneurysms. Correlation analyses revealed the D/W value was positively associated with the EL (R=0.442, p<0.01). Conclusion D/W and EL might be the most two favorable factors to predict rupture risk of MCA bifurcation aneurysms. PMID:28881112

  4. Identification of neurovascular changes associated with cerebral amyloid angiopathy from subject-specific hemodynamic response functions.

    PubMed

    Williams, Rebecca J; Goodyear, Bradley G; Peca, Stefano; McCreary, Cheryl R; Frayne, Richard; Smith, Eric E; Pike, G Bruce

    2017-01-01

    Cerebral amyloid angiopathy (CAA) is a small-vessel disease preferentially affecting posterior brain regions. Recent evidence has demonstrated the efficacy of functional MRI in detecting CAA-related neurovascular injury, however, it is unknown whether such perturbations are associated with changes in the hemodynamic response function (HRF). Here we estimated HRFs from two different brain regions from block design activation data, in light of recent findings demonstrating how block designs can accurately reflect HRF parameter estimates while maximizing signal detection. Patients with a diagnosis of probable CAA and healthy controls performed motor and visual stimulation tasks. Time-to-peak (TTP), full-width at half-maximum (FWHM), and area under the curve (AUC) of the estimated HRFs were compared between groups and to MRI features associated with CAA including cerebral microbleed (CMB) count. Motor HRFs in CAA patients showed significantly wider FWHM ( P = 0.006) and delayed TTP ( P = 0.03) compared to controls. In the patient group, visual HRF FWHM was positively associated with CMB count ( P = 0.03). These findings indicate that hemodynamic abnormalities in patients with CAA may be reflected in HRFs estimated from block designs across different brain regions. Moreover, visual FWHM may be linked to structural MR indications associated with CAA.

  5. Hemodynamic changes with high infusion rates of lipid emulsion. Experimental study in swine.

    PubMed

    Udelsmann, Artur; Melo, Marcos De Simone

    2015-11-01

    To evaluate hemodynamic changes caused by sole intravenous infusion of lipid emulsion with doses recommended for treatment of drug-related toxicity. Large White pigs underwent general anesthesia, tracheal intubation was performed, and mechanical ventilation was instituted. Hemodynamic variables were recorded using invasive blood pressure and pulmonary artery catheterization. Baseline hemodynamic measurements were obtained after a 30-minute stabilization period. An intravenous bolus injection of 20% lipid emulsion at 1.5 ml/kg was administered. Additional hemodynamic measurements were made after 1 minute, followed by a continuous intravenous lipid infusion of 0.25 ml/kg/min. Further measurements were carried out at 10, 20 and 30 minutes, when the infusion was doubled to 0.5 ml/kg/min. Assessment of hemodynamic changes were then made at 40, 50 and 60 minutes. Lipid infusion did not influence cardiac output or heart rate, but caused an increase in arterial blood pressure, mainly pulmonary blood pressure due to increased vascular resistance. Ventricular systolic stroke work consequently increased with greater repercussions on the right ventricle. In doses used for drug-related toxicity, lipid emulsion cause significant hemodynamic changes with hypertension, particularly in the pulmonary circulation and increase in vascular resistance, which is a factor to consider prior to use of these solutions.

  6. Glucose levels and hemodynamic changes in patients submitted to routine dental treatment with and without local anesthesia

    PubMed Central

    Bortoluzzi, Marcelo Carlos; Manfro, Rafael; Nardi, Anderson

    2010-01-01

    OBJECTIVE: The aim of this study was to (1) observe the extent to which hemodynamic and glucose measurements change in patients submitted to a dental procedure with and without a local anesthetic and a vasoconstrictor (LAVA; 2% mepivacaine with adrenaline 1∶100,000) and (2) correlate those parameters with the patients' anxiety levels. METHOD: This was an unblinded, random, prospective, and observational study with paired groups. Patients were evaluated during two different consultations during which they either did or did not receive a local anesthetic/vasoconstrictor. RESULTS: Thirty‐seven patients ranging in age from 18 to 45 years (mean 30.4 ± 5.5 years) were evaluated. Hemodynamic parameters, including systolic blood pressure, diastolic blood pressure, heart rate, and glucose levels, did not change significantly in healthy patients, regardless of whether a LAVA was administered during the dental treatment. CONCLUSION: The patients' anxiety statuses neither varied significantly nor showed any correlation with the studied hemodynamic parameters and glucose levels, regardless of whether local anesthetics were used. PMID:21120297

  7. Glucose levels and hemodynamic changes in patients submitted to routine dental treatment with and without local anesthesia.

    PubMed

    Bortoluzzi, Marcelo Carlos; Manfro, Rafael; Nardi, Anderson

    2010-01-01

    The aim of this study was to (1) observe the extent to which hemodynamic and glucose measurements change in patients submitted to a dental procedure with and without a local anesthetic and a vasoconstrictor (LAVA; 2% mepivacaine with adrenaline 1100,000) and (2) correlate those parameters with the patients' anxiety levels. This was an unblinded, random, prospective, and observational study with paired groups. Patients were evaluated during two different consultations during which they either did or did not receive a local anesthetic/vasoconstrictor. Thirty-seven patients ranging in age from 18 to 45 years (mean 30.4 ± 5.5 years) were evaluated. Hemodynamic parameters, including systolic blood pressure, diastolic blood pressure, heart rate, and glucose levels, did not change significantly in healthy patients, regardless of whether a LAVA was administered during the dental treatment. The patients' anxiety statuses neither varied significantly nor showed any correlation with the studied hemodynamic parameters and glucose levels, regardless of whether local anesthetics were used.

  8. Venous hemodynamic changes in lower limb venous disease: the UIP consensus according to scientific evidence.

    PubMed

    Lee, Byung B; Nicolaides, Andrew N; Myers, Kenneth; Meissner, Mark; Kalodiki, Evi; Allegra, Claudio; Antignani, Pier L; Bækgaard, Niels; Beach, Kirk; Belcaro, Giovanni; Black, Stephen; Blomgren, Lena; Bouskela, Eliete; Cappelli, Massimo; Caprini, Joseph; Carpentier, Patrick; Cavezzi, Attilio; Chastanet, Sylvain; Christenson, Jan T; Christopoulos, Demetris; Clarke, Heather; Davies, Alun; Demaeseneer, Marianne; Eklöf, Bo; Ermini, Stefano; Fernández, Fidel; Franceschi, Claude; Gasparis, Antonios; Geroulakos, George; Gianesini, Sergio; Giannoukas, Athanasios; Gloviczki, Peter; Huang, Ying; Ibegbuna, Veronica; Kakkos, Stavros K; Kistner, Robert; Kölbel, Tilo; Kurstjens, Ralph L; Labropoulos, Nicos; Laredo, James; Lattimer, Christopher R; Lugli, Marzia; Lurie, Fedor; Maleti, Oscar; Markovic, Jovan; Mendoza, Erika; Monedero, Javier L; Moneta, Gregory; Moore, Hayley; Morrison, Nick; Mosti, Giovanni; Nelzén, Olle; Obermayer, Alfred; Ogawa, Tomohiro; Parsi, Kurosh; Partsch, Hugo; Passariello, Fausto; Perrin, Michel L; Pittaluga, Paul; Raju, Seshadri; Ricci, Stefano; Rosales, Antonio; Scuderi, Angelo; Slagsvold, Carl E; Thurin, Anders; Urbanek, Tomasz; M VAN Rij, Andre; Vasquez, Michael; Wittens, Cees H; Zamboni, Paolo; Zimmet, Steven; Ezpeleta, Santiago Z

    2016-06-01

    There are excellent guidelines for clinicians to manage venous diseases but few reviews to assess their hemodynamic background. Hemodynamic concepts that evolved in the past have largely remained unchallenged in recent decades, perhaps due to their often complicated nature and in part due to emergence of new diagnostic techniques. Duplex ultrasound scanning and other imaging techniques which evolved in the latter part of the 20th century have dominated investigation. They have greatly improved our understanding of the anatomical patterns of venous reflux and obstruction. However, they do not provide the physiological basis for understanding the hemodynamics of flow, pressure, compliance and resistance. Hemodynamic investigations appear to provide a better correlation with post-treatment clinical outcome and quality of life than ultrasound findings. There is a far better prospect for understanding the complete picture of the patient's disability and response to management by combining ultrasound with hemodynamic studies. Accordingly, at the instigation of Dr Angelo Scuderi, the Union Internationale de Phlebologie (UIP) executive board commissioned a large number of experts to assess all aspects of management for venous disease by evidence-based principles. These included experts from various member societies including the European Venous Forum (EVF), American Venous Forum (AVF), American College of Phlebology (ACP) and Cardiovascular Disease Educational and Research Trust (CDERT). Their aim was to confirm or dispel long-held hemodynamic principles and to provide a comprehensive review of venous hemodynamic concepts underlying the pathophysiology of lower limb venous disorders, their usefulness for investigating patients and the relevant hemodynamic changes associated with various forms of treatment. Chapter 1 is devoted to basic hemodynamic concepts and normal venous physiology. Chapter 2 presents the mechanism and magnitude of hemodynamic changes in acute deep vein

  9. Echocardiographic Evaluation of Hemodynamic Changes in Left-Sided Heart Valves in Pregnant Women With Valvular Heart Disease.

    PubMed

    Samiei, Niloufar; Amirsardari, Mandana; Rezaei, Yousef; Parsaee, Mozhgan; Kashfi, Fahimeh; Hantoosh Zadeh, Sedigheh; Beikmohamadi, Somayeh; Fouladi, Masoumeh; Hosseini, Saeid; Peighambari, Mohammad Mehdi; Mohebbi, Ahmad

    2016-10-01

    Physiologic changes during pregnancy can deteriorate or improve patients' hemodynamic status in the setting of valvular heart disease. There are sparse data regarding the effect of pregnancy on valve hemodynamics in normal pregnant women with known valvular heart disease. In a prospective study from July 2014 to January 2016, a total of 52 normal pregnant women who had mitral stenosis, aortic stenosis, or a history of mitral valve or aortic valve replacements were assessed. All patients underwent echocardiographic examinations and hemodynamic parameters were measured for both the mitral valve and aortic valve at first, second, and third trimesters. The parameters included mean gradient, peak gradient, mean gradient/heart rate, peak gradient/heart rate, pressure halftime, dimensionless velocity index, and valve area. Although most hemodynamic parameters (i.e., mean gradient, peak gradient, mean gradient/heart rate, and peak gradient/heart rate) increased approximately 50% from first to second trimester and first to third trimester (p <0.05) but those remained stable at third compared with second trimester (p >0.05). The ratio of changes between trimesters for valve area and dimensionless velocity index were comparable. No clinical decompensations were observed except for 3 and 7 cases of deterioration to functional class II at second and third trimesters, respectively. In conclusion, during a full-term and uncomplicated pregnancy, mitral and aortic valve gradients increase without significant changes in valve area that are more marked between the second and first trimester than between the third and second trimester. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Early Cerebral Hemodynamic, Metabolic, and Histological Changes in Hypoxic–Ischemic Fetal Lambs during Postnatal Life

    PubMed Central

    Rey-Santano, Carmen; Mielgo, Victoria E.; Gastiasoro, Elena; Murgia, Xabier; Lafuente, Hector; Ruiz-del-Yerro, Estibaliz; Valls-i-Soler, Adolf; Hilario, Enrique; Alvarez, Francisco J.

    2011-01-01

    The hemodynamic, metabolic, and biochemical changes produced during the transition from fetal to neonatal life may be aggravated if an episode of asphyxia occurs during fetal life. The aim of the study was to examine regional cerebral blood flow (RCBF), histological changes, and cerebral brain metabolism in preterm lambs, and to analyze the role of oxidative stress in the first hours of postnatal life following severe fetal asphyxia. Eighteen chronically instrumented newborn lambs were randomly assigned to either a control group or the hypoxic–ischemic (HI) group, in which case fetal asphyxia was induced just before delivery. All the animals were maintained on intermittent positive pressure ventilation for 3 h after delivery. During the HI insult, the injured group developed acidosis, hypoxia, hypercapnia, lactic acidosis, and tachycardia (relative to the control group), without hypotension. The intermittent positive pressure ventilation transiently improved gas exchange and cardiovascular parameters. After HI injury and during ventilatory support, there continued to be an increased RCBF in inner regions among the HI group, but no significant differences were detected in cortical flow compared to the control group. Also, the magnitude of the increase in TUNEL positive cells (apoptosis) and antioxidant enzymes, and decrease of ATP reserves was significantly greater in the brain regions where the RCBF was not higher. In conclusion, our findings identify early metabolic, histological, and hemodynamic changes involved in brain damage in premature asphyxiated lambs. Such changes have been described in human neonates, so our model could be useful to test the safety and the effectiveness of different neuroprotective or ventilation strategies applied in the first hours after fetal HI injury. PMID:21960958

  11. Association of television viewing time with central hemodynamic parameters and the radial augmentation index in adults.

    PubMed

    Recio-Rodriguez, Jose I; Gomez-Marcos, Manuel A; Patino-Alonso, Maria C; Romaguera-Bosch, Montserrat; Grandes, Gonzalo; Menendez-Suarez, Marta; Lema-Bartolome, Jorge; Gonzalez-Viejo, Natividad; Agudo-Conde, Cristina; Garcia-Ortiz, Luis

    2013-04-01

    We conducted a study to explore the relationship between television viewing time and central hemodynamic parameters and the radial augmentation index (AIx) in adults. Random sampling was used to select 732 individuals who attended primary-care centers as subjects for the study. The self-reported time that these individuals spent in viewing television was elicited with a questionnaire and included the number of hours that they spent watching television while sitting or lying down. The subjects' physical activity was estimated through accelerometers attached to their waists. Central hemodynamic parameters and the peripheral augmentation index adjusted for a heart rate of 75 bpm (PAIx75) were measured with pulse-wave application software (A-Pulse CASP). The subjects' systolic blood pressure (SBP) (central and peripheral), pulse pressure, and radial AIx showed significant differences between tertiles of television viewing time, with the lowest values in the first tertile (P < 0.01). After adjustment for age and sex, a multiple linear regression analysis showed an association of television viewing time with office SBP. Although the association of television viewing time with central SBP followed the same trend as for office BP, it did not reach statistical significance. After adjustment for age, sex, waist-to-height ratio, physical activity reflected by accelerometer data (counts/min), high-density lipoprotein cholesterol, smoking, antihypertensive and antidiabetic medication, and the use of lipid-lowering drugs, an increase in PAIx75 of 0.22 was estimated for each hour of increase in television viewing time (P < 0.01). Television viewing time was directly correlated with PAIx75 in an adult population. This correlation was maintained even after adjustment for physical activity, age, sex, and other cardiovascular risk factors.

  12. Quantifying tissue hemodynamics by NIRS versus DOT: global versus focal changes in cerebral hemodynamics

    NASA Astrophysics Data System (ADS)

    Boas, David A.; Cheng, Xuefeng; Marota, John A.; Mandeville, Joseph B.

    1999-09-01

    Near infrared spectroscopy (NIRS) is used to quantify changes in oxy-hemoglobin (HbO) and deoxy-hemoglobin (Hb) concentrations in tissue. The analysis uses the modified Beer-Lambert law, which is generally valid for quantifying global concentration changes. We examine the errors that result from analyzing focal changes in HbO and Hb concentrations. We find that the measured focal change in HbO and Hb are linearly proportional to the actual focal changes but that the proportionally constants are different. Thus relative changes in HbO and Hb cannot, in general, be quantified. However, we show that under certain circumstances it is possible to quantify these relative changes. This builds the case for diffuse optical tomography (DOT) which in general should be able to quantify focal changes in HbO and Hb through the use of image reconstruction algorithms that deconvolve the photon diffusion point-spread-function. We demonstrate the differences between NIRS and DOT using a rat model of somatosensory stimulation.

  13. Longitudinal changes in fetal biometry and cerebroplacental hemodynamics in fetuses with congenital heart disease.

    PubMed

    Ruiz, A; Cruz-Lemini, M; Masoller, N; Sanz-Cortés, M; Ferrer, Q; Ribera, I; Martínez, J M; Crispi, F; Arévalo, S; Gómez, O; Pérez-Hoyos, S; Carreras, E; Gratacós, E; Llurba, E

    2017-03-01

    To determine the longitudinal behavior of fetal biometric measures and cerebroplacental hemodynamics throughout gestation in fetuses with congenital heart disease (CHD). Fetal biometry and Doppler hemodynamics (uterine artery (UtA), umbilical artery (UA) and fetal middle cerebral artery (MCA)) were measured serially in a cohort of consecutive fetuses diagnosed with CHD. Evaluations were made at various time points, from diagnosis (20-25 weeks) to delivery, with at least two measurements per fetus that were at least 2 weeks apart. Fetuses were classified into three groups according to the pattern of blood supply to the brain (placental vs systemic) that would be expected on the basis of the type of CHD. All parameters were transformed into Z-scores. A linear mixed model to analyze repeated measurements was constructed for each parameter to assess its behavior throughout gestation. Four hundred and forty-four ultrasound examinations were performed in 119 CHD fetuses, with a median of two measurements per fetus. The fetuses presented a small head at diagnosis (biparietal diameter (BPD) Z-score, -1.32 ± 0.99; head circumference (HC) Z-score, -0.79 ± 1.02), which remained small throughout gestation. UtA and UA pulsatility indices (PI) showed a significant increase towards the end of pregnancy, whereas no significant changes were observed in MCA-PI or cerebroplacental ratio (CPR) with gestational age. Both MCA and CPR presented significant differences in longitudinal behavior between CHD groups, while BPD and HC did not. CHD fetuses have a relatively small head from the second trimester of pregnancy, regardless of the type of CHD anomaly, and increasing resistance in the UtA and UA as pregnancy progresses, suggestive of increasing degree of placental impairment. Our findings indicate the early onset of mechanisms that could lead to poorer neurodevelopment later in life. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd. Copyright © 2016 ISUOG. Published by

  14. Portalsystemic hemodynamic changes in chronic severe hepatitis B: An ultrasonographic study

    PubMed Central

    Su, Zhong-Zhen; Shan, Hong; Ke, Wei-Min; He, Bing-Jun; Zheng, Rong-Qin

    2008-01-01

    AIM: To evaluate portalsystemic hemodynamic changes in chronic severe hepatitis B. METHODS: Hemodynamic parameters included portal vein diameter (PVD), portal vein peak velocity (PVPV), portal vein volume (PVV), spleen length (SPL), spleen vein diameter (SPVD), spleen vein volume (SPVV) and umbilical vein recanalization. They were measured by Color Doppler ultrasonography in 36 patients with chronic severe hepatitis B, compared with 51 normal controls, 61 patients with chronic hepatitis B, 46 patients with compensable cirrhosis, and 36 patients with decompensable cirrhosis. RESULTS: In the group of chronic severe hepatitis B, PVD (12.38 ± 1.23 mm) was significantly different from the normal control, compensable cirrhosis and decompensable cirrhosis groups (P = 0.000-0.026), but not significantly different from the chronic hepatitis group. PVPV (16.15 ± 3.82 cm/s) dropped more significantly in the chronic severe hepatitis B group than the normal control, chronic hepatitis B and compensable cirrhosis groups (P = 0.000-0.011). PVV (667.53 ± 192.83 mL/min) dropped significantly as compared with the four comparison groups (P = 0.000-0.004). SPL (120.42 ± 18.36 mm) and SPVD (7.52 ± 1.52 mm) were longer in the normal control and chronic hepatitis B groups (P = 0.000-0.009), yet they were significantly shorter than those in the decompensable cirrhosis group (P = 0.000). SPVV (242.51 ± 137.70 mL/min) was also lower than the decompensable cirrhosis group (P = 0.000). The umbilical vein recanalization rate (75%) was higher than the chronic hepatitis B and compensable cirrhosis groups. In the course of progression from chronic hepatitis to decompensable cirrhosis, PVD, SPL and SPVD gradually increased and showed significant differences between every two groups (P = 0.000-0.002). CONCLUSION: Patients with chronic severe hepatitis B have a tendency to develop acute portal hypertension, resulting in significantly reduced portal vein perfusion. Observation of the

  15. [CLINICAL-HEMODYNAMIC PECULIARITIES OF THE COURSE OF HEMODYNAMIC ISCHEMIC STROKE IN ACUTE PERIOD].

    PubMed

    Shkrobot, S; Sokhor, N; Milevska-Vovchuk, L; Yasniy, O; Shkrobot, L

    2017-02-01

    The aim of the research is to study the peculiarities of cardiac morphometric parameters, the parameters of central hemodynamics and their impact on the course of hemodynamic ischemic stroke in acute period. 116 patients were performed Echo-Doppler-cardiography in acute period of hemodynamic ischemic stroke in order to evaluate cardiac morphometric parameters. These patients were also performed transcranial duplex scanning. The results established that among significant clinical factors that influence the course of the acute period of hemodynamic ischemic stroke the most important are: the size of the focus, the level of consciousness on the 1st day, primary systolic arterial pressure, age of the patient. Hemodynamic ischemic stroke occurs on the background of changes of cardiac morphometric parameters and the disorders of the central hemodynamics. There is a close connection between the severity of hemodynamic ischemic stroke on the 7th and 14th day with the ejection fraction, the size of left atrium, the thickness of posterior wall of left ventricle, final diastolic size of left ventricle. The interrelation between the parameters of cerebral hemodynamics and cardiac morphometric parameters was established. cardiac morphometric parameters and parameters of central hemodynamics can be predictors of the course of hemodynamic ischemic stroke in acute period.

  16. Changes in Conjunctival Hemodynamics Predict Albuminuria in Sickle Cell Nephropathy

    PubMed Central

    Valeshabad, Ali Kord; Wanek, Justin; Saraf, Santosh L.; Gaynes, Bruce I.; Gordeuk, Victor R.; Molokie, Robert E.; Shahidi, Mahnaz

    2015-01-01

    Background Albuminuria is an early manifestation of deterioration in renal function in subjects with sickle cell disease (SCD). Hyperfiltration may be an early mechanism for kidney damage in SCD. The purpose of the current study was to determine the association between conjunctival hemodynamics and albuminuria in SCD subjects with preserved glomerular filtration rate. Methods Conjunctival microcirculation imaging was performed to measure conjunctival diameter (D) and axial blood velocity (V) in 35 SCD and 10 healthy control subjects. Albuminuria, defined as albumin excretion ratio (AER) was obtained from the medical charts. Based on the 95% confidence interval of conjunctival V in control subjects (0.40 - 0.60 mm/s), SCD subjects were allocated to three groups: V1 < 0.40 mm/s (N = 7), V2 of 0.40 – 0.60 mm/s (N = 18), and V3 ≥ 0.60 mm/s (N = 10). Results Mean log(AER) measurements in the V1, V2, and V3 groups were 1.08 ± 0.67 mg/g creatinine, 1.39 ± 0.59 mg/g creatinine, and 2.00 ± 0.91 mg/g creatinine, respectively, and followed a positive linear trend from the V1 to V3 groups (p = 0.01). By multivariate linear regression analysis, conjunctival V significantly correlated with albuminuria (p = 0.01) independent of age, blood pressure, α-thalassemia, hematocrit, white blood cell count, and lactate dehydrogenase concentration. Conclusions Increased conjunctival velocity is associated with albuminuria in sickle cell subjects. Assessment of conjunctival microvascular hemodynamics may improve our understanding of the pathophysiology and clinical course of sickle cell nephropathy. PMID:26278102

  17. [Hemodynamic and respiratory changes in cervical peridural anesthesia].

    PubMed

    Santanchè, G; Goedecke, A

    1989-11-01

    Regional anesthesia as a method of avoiding stress and preserving the immunological system has found a solid place in the armamentarium of anesthesia departments. Its applicability for anesthesia of higher segments is controversial. In order to test the reliability of this method, at 7 perioperative measuring points we studied respiratory and circulatory parameters of 17 patients undergoing breast surgery. Access to the peridural space was via C6/7 or C7/T1 by catheterization with the hanging-drop method. The respiratory and circulatory parameters were determined by direct measurement of arterial and pulmonary-arterial pressures and by arterial and mixed-venous blood samples. The main criterion was determination of the arterio-venous oxygen difference. It was shown that the cardiovascular and respiratory integrity of the organism remained unaffected. The most marked changes in relation to the starting point were seen at measuring point 5 (40 min after beginning anesthesia): heart rate -22.4% (p less than 0.05), mean arterial pressure -35.1% (p less than 0.05), mean pulmonary-arterial pressure + 18.1% (NS), mixed-venous oxygenation -5.5% (NS), arteriovenous oxygen difference +25.9% (NS) arterial pO2 -4.4% (NS) and pCO2 +7.9% (p less than 0.05). --In the hands of an anesthetist fully acquainted with conduction anesthesia, cervical peridural anesthesia for appropriate indications may be proposed as an alternative anesthesiological method.

  18. Hemodynamic response characteristics of healthy people to changes in meteorological and geomagnetic factors in the north

    NASA Astrophysics Data System (ADS)

    Zenchenko, T. A.; Varlamova, N. G.

    2015-12-01

    This paper analyzes the influence of variations in meteorological and geomagnetic factors on hemodynamic parameters (HP) in 27 healthy volunteers who are residents of Syktyvkar (daily monitoring of blood pressure (BP) and heart rate (HR) and stroke and cardiac output for the period from December 1, 2003, to December 31, 2004). It is shown that temperature variations and geomagnetic activity level (GMA) make the greatest impact on HP changes (85 and 48% cases, respectively). The BP level increases with decreasing temperature and with increasing levels of GMA. The sensitivity of systolic and diastolic blood pressure to the meteorological and geomagnetic factors is approximately twice as high as the sensitivity of other HP to them. The individual values of seasonal changes in BP parameters are 4-9 mmHg for systolic blood pressure and 3-6 mmHg for diastolic blood pressure. The estimates of the characteristics of meteorological and geomagnetic sensitivity in residents of northern latitudes are in good agreement with the results obtained by us earlier for other climatic zones and geomagnetic conditions, logically complementing and enhancing the common space-time picture of the reactions of the human body to external impacts.

  19. [Hemodynamic and humoral changes in long-distance athletes].

    PubMed

    Corea, L; Bentivoglio, M; Verdecchia, P; Provvidenza, M; Milia, U; Pollavini, G

    1983-12-01

    Cardiac anatomy and function, and some biohumoral parameters, have been examined in 11 long-distance olympic runners, and in 11 healthy untrained control subjects. Echocardiographic methods and computed reading of tracings were adopted. Long-distance runners were also studied within 2 minutes after the end of a 30 Km race. At rest, the athletes had thicker interventricular septa and, posterior walls, higher left ventricular mass index, larger end-diastolic dimensions, cardiac index and stroke index compared to the untrained subjects (all P less than 0.01). Resting heart rate was lower in runners (P less than 0.01). In runners, competitive exercise test induced significant haemodynamic changes (increases in cardiac index, heart rate, stroke index, ejection fraction [all P less than 0.01], decreases in end-systolic dimensions and peripheral vascular resistance [both P less than 0.01]). After exercise, runners showed massive increases both of norepinephrine and epinephrine serum levels (measured in 4 subjects), an increase, in haematocrit and plasma glucose concentration, and a decrease in plasma potassium concentration (all P less than 0.01). In conclusion, olympic long-distance runners have increased cardiac dimensions and wall thickness at rest as compared with healthy untrained subjects matched for age and resting blood pressure. In the former group, a competitive long-distance test results in marked haemodynamic changes, with massive increase in plasma catecholamine concentration and concomitant reduction in plasma potassium concentration. This combination is potentially hazardous, and warrants further investigation.

  20. Changes in cerebral hemodynamics during a sleep-deprived video-electroencephalogram in healthy children.

    PubMed

    Peng, Bingwei; Li, Jialing; Wang, Jing; Liang, Xiuqiong; Zheng, Zhiying; Mai, Jianning

    2016-07-01

    This study investigates the cerebral hemodynamic changes during a routine sleep-deprived video-electroencephalogram (SD-VEEG) in healthy children. Forty-two children with normal intelligence were examined. The children were 5-14 years of age, and their electroencephalograms (EEGs) were within the normal range. Each subject was deprived of a routine night's sleep and then examined during non-drug-induced sleep in the daytime. The awake and sleep stages were evaluated using EEGs, according to the American Academy of Sleep Medicine. Stable transcranial Doppler ultrasound (TCD) tracings through real-time TCD-VEEG monitoring were recorded. The mean systolic cerebral blood flow velocity (CBFV), diastolic CBFV, pulsatility index and resistance index of each artery were analyzed for 30 s per stage. A multivariate analysis of variance was conducted to compare the hemodynamic parameters for the awake stage versus light sleep and deep sleep stages. Non-rapid eye movement sleep was associated with an increased CBFV in the middle (164.38  ±  27.28) and anterior cerebral artery (131.81  ±  21.55) during light sleep (stages N1 and N2) (P  =  0.0001), a reduced systolic CBFV in all vascular arteries (LMCA, 138.73  ±  20.64; LACA, 108.33  ±  22.33; LPCA, 83.9  ±  18.6) during deep sleep (stage N3) compared with light sleep (P  =  0.0001), and a sustained increased PI (LMCA, 0.92  ±  0.13; LACA, 0.964  ±  0.18) during deep sleep (P  <  0.05). These findings indicate distinct cerebral hemodynamic alterations during SD-VEEG in children. This study utilized real-time TCD-VEEG monitoring during SD-EEG to further investigate neurovascular coupling in interictal epileptic discharges and understand its potential influence on cognition in the developing brain.

  1. [The Effect of Preoperative Oral Rehydration on Hemodynamic Changes during Induction of Anesthesia and Intraoperative Fluid Management].

    PubMed

    Tsutsui, Mari; Ishigaki, Sayaka; Kanaya, Ayana; Kawaguchi, Saori; Ogura, Takahiro

    2015-04-01

    Preoperative oral rehydration solution (ORS) prevents dehydration before surgery. Therefore taking enough ORS possibly reduces the hemodynamic changes during induction of anesthesia, and reduces the amount of fluid needed during anesthesia. Forty patients undergoing elective surgery were randomly assigned to two groups: drinking 1,500 ml ORS 6 to 2 hours before anesthesia (ORS group) and nothing by mouth from 6 hours before anesthesia (Control group). Anesthesia induction was performed using propofol and remifentanil. To evaluate the hemodynamic changes, hemodynamic parameters including heart rate, blood pressure, cardiac index (CI), and stroke volume variation (SVV) were recorded before induction, after propofol administration, and after remifentanil administration. Total urine volume and the amount of fluid were also recorded at the end of the anesthesia. In ORS group, CI showed a significantly higher value after propofol administration (P = 0.046). SVV was significantly lower (P < 0.0001) and total amount of fluid during anesthesia was significantly reduced (P < 0.0001) in ORS group. Preoperative oral rehydration increases circulating blood volume, it keeps high CI during induction of anesthesia, and reduces the amount of intraoperative fluid.

  2. Prevention of hemodynamic and vascular albumin filtration changes in diabetic rats by aldose reductase inhibitors

    SciTech Connect

    Tilton, R.G.; Chang, K.; Pugliese, G.; Eades, D.M.; Province, M.A.; Sherman, W.R.; Kilo, C.; Williamson, J.R. )

    1989-10-01

    This study investigated hemodynamic changes in diabetic rats and their relationship to changes in vascular albumin permeation and increased metabolism of glucose to sorbitol. The effects of 6 wk of streptozocin-induced diabetes and three structurally different inhibitors of aldose reductase were examined on (1) regional blood flow (assessed with 15-microns 85Sr-labeled microspheres) and vascular permeation by 125I-labeled bovine serum albumin (BSA) and (2) glomerular filtration rate (assessed by plasma clearance of 57Co-labeled EDTA) and urinary albumin excretion (determined by radial immunodiffusion assay). In diabetic rats, blood flow was significantly increased in ocular tissues (anterior uvea, posterior uvea, retina, and optic nerve), sciatic nerve, kidney, new granulation tissue, cecum, and brain. 125I-BSA permeation was increased in all of these tissues except brain. Glomerular filtration rate and 24-h urinary albumin excretion were increased 2- and 29-fold, respectively, in diabetic rats. All three aldose reductase inhibitors completely prevented or markedly reduced these hemodynamic and vascular filtration changes and increases in tissue sorbitol levels in the anterior uvea, posterior uvea, retina, sciatic nerve, and granulation tissue. These observations indicate that early diabetes-induced hemodynamic changes and increased vascular albumin permeation and urinary albumin excretion are aldose reductase-linked phenomena. Discordant effects of aldose reductase inhibitors on blood flow and vascular albumin permeation in some tissues suggest that increased vascular albumin permeation is not entirely attributable to hemodynamic change.

  3. Multiple sclerosis-related white matter microstructural change alters the BOLD hemodynamic response.

    PubMed

    Hubbard, Nicholas A; Turner, Monroe; Hutchison, Joanna L; Ouyang, Austin; Strain, Jeremy; Oasay, Larry; Sundaram, Saranya; Davis, Scott; Remington, Gina; Brigante, Ryan; Huang, Hao; Hart, John; Frohman, Teresa; Frohman, Elliot; Biswal, Bharat B; Rypma, Bart

    2016-11-01

    Multiple sclerosis (MS) results in inflammatory damage to white matter microstructure. Prior research using blood-oxygen-level dependent (BOLD) imaging indicates MS-related alterations to brain function. What is currently unknown is the extent to which white matter microstructural damage influences BOLD signal in MS. Here we assessed changes in parameters of the BOLD hemodynamic response function (HRF) in patients with relapsing-remitting MS compared to healthy controls. We also used diffusion tensor imaging to assess whether MS-related changes to the BOLD-HRF were affected by changes in white matter microstructural integrity. Our results showed MS-related reductions in BOLD-HRF peak amplitude. These MS-related amplitude decreases were influenced by individual differences in white matter microstructural integrity. Other MS-related factors including altered reaction time, limited spatial extent of BOLD activity, elevated lesion burden, or lesion proximity to regions of interest were not mediators of group differences in BOLD-HRF amplitude. Results are discussed in terms of functional hyperemic mechanisms and implications for analysis of BOLD signal differences. © The Author(s) 2015.

  4. Optimization strategies for evaluation of brain hemodynamic parameters with qBOLD technique.

    PubMed

    Wang, Xiaoqi; Sukstanskii, Alexander L; Yablonskiy, Dmitriy A

    2013-04-01

    Quantitative blood oxygenation level dependent technique provides an MRI-based method to measure tissue hemodynamic parameters such as oxygen extraction fraction and deoxyhemoglobin-containing (veins and prevenous part of capillaries) cerebral blood volume fraction. It is based on a theory of MR signal dephasing in the presence of blood vessel network and experimental method-gradient echo sampling of spin echo previously proposed and validated on phantoms and animals. In vivo human studies also demonstrated feasibility of this approach but also recognized that obtaining reliable results requires high signal-to-noise ratio in the data. In this paper, we analyze in detail the uncertainties of the quantitative blood oxygenation level dependent parameter estimates in the framework of the Bayesian probability theory, namely, we examine how the estimated parameters oxygen extraction fraction and deoxygenated cerebral blood volume fraction depend on their "true values," signal-to-noise ratio, and data sampling strategies. On the basis of this analysis, we develop strategies for optimization of the quantitative blood oxygenation level dependent technique for deoxygenated cerebral blood volume and oxygen extraction fraction evaluation. In particular, it is demonstrated that the use of gradient echo sampling of spin echo sequence allows substantial decrease of measurement errors as the data are acquired on both sides of spin echo. We test our theory on phantom mimicking the structure of blood vessel network. A 3D gradient echo sampling of spin echo pulse sequence is used for the acquisition of the MRI signal that was subsequently analyzed by Bayesian Application Software. The experimental results demonstrated a good agreement with theoretical predictions.

  5. Effects on hemodynamic variables and echocardiographic parameters after a stellate ganglion block in 15 healthy volunteers.

    PubMed

    Puente de la Vega Costa, Katia; Gómez Perez, Miquel A; Roqueta, Cristina; Fischer, Lorenz

    2016-05-01

    The sympathetic nervous system has an important role in generating pain. Various pathomechanisms are involved that respond well to the application of local anesthetics (LA), for example to the stellate ganglion block (SGB). We wanted to know more about the effects of SGB on cardiovascular parameters. We included 15 healthy volunteers; another 15 healthy volunteers as a control group (sham injection of LA). In order to produce a more precise SGB, we employed only a small volume of LA (3mL), a LA with a lower permeability (procaine 1%), and a modified injection technique. Systolic and diastolic blood pressure (SBP, DBP), heart rate (HR), and echocardiographic parameters were recorded before and after SGB. We also investigated whether there are side differences (left and right SBG). At baseline all parameters were within the normal range. After performing right and left SGB DBP significantly increased (on the right side from 68.73±8.61 to 73.53±11.10, p=0.015; on the left side from 70.66±13.01 to 77.93±10.40, p=0.003). In the control group no increase in DBP was observed. No side-specific differences were found, except a significant reduction in the maximum velocity of myocardial contraction during the systole with left-sided SGB. Even with our methods we could not prevent the simultaneous occurrence of a partial parasympatholytic effect. For this reason, the SGB has only minor hemodynamic effects, which is desirable as it enhances the safety of the SGB. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  6. Changes in hemodynamic response to mental stress with heart rate feedback training.

    PubMed

    Goodie, J L; Larkin, K T

    2001-12-01

    This study was designed to examine underlying hemodynamic changes that accompany observed reductions in heart rate (HR) response to mental stress following HR feedback training. Twenty-five college males, assigned to either a HR feedback training group (FB+) or a control group (FB-), were presented with a videogame and mental arithmetic challenge, as HR, blood pressure, and impedance cardiography-derived measures of hemodynamic functioning were recorded. During training, the FB+ group received HR feedback and the FB- group was not provided with HR feedback while playing a videogame. At posttraining, results revealed that the FB+ group exhibited significantly lower HR, systolic blood pressure, stroke volume, and total peripheral resistance responses to the videogame compared to that at pretraining. There was no evidence that the acquired skills generalized to a mental arithmetic task. These results suggest that HR feedback training is an effective method for reducing cardiovascular and hemodynamic responses to a mental stressor; however, the generalizability of this effect remains questionable.

  7. The influence of genetic polymorphisms on performance and cardiac and hemodynamic parameters among Brazilian soccer players.

    PubMed

    Dionísio, Thiago José; Thiengo, Carlos Rogério; Brozoski, Daniel Thomas; Dionísio, Evandro José; Talamoni, Guilherme Augusto; Silva, Roberto Braga; Garlet, Gustavo Pompermaier; Santos, Carlos Ferreira; Amaral, Sandra Lia

    2017-06-01

    This study investigated whether ACTN3 R577X, AMPD1 C34T, I/D ACE, and M235T AGT polymorphisms can affect performance tests such as jumping, sprinting, and endurance in 220 young male athletes from professional minor league soccer team from São Paulo Futebol Clube, Brazil. I/D ACE and M235T AGT polymorphisms were also analyzed according to cardiac and hemodynamic parameters. Athletes were grouped or not by age. DNA from saliva and Taqman assays were used for genotyping 220 athletes and the results were associated with performance tests. Ventricle mass, ventricle end-diastolic diameter, end-diastolic volume, and ejection fraction were assessed by echocardiogram. Arterial pressure, heart rate, and oximetry were assessed by a cardioscope. The main results of this study were that athletes who carried RR/RX (ACTN3) and DD (ACE) genotypes presented better performance during jump and sprint tests. On the other hand, athletes with ID/II genotype presented better results during endurance test, while AGT genotypes did not seem to favor the athletes during the evaluated physical tests. CC genotype (AMPD1) only favored the athletes during 10-m sprint test. Although there are environmental interactions influencing performance, the present results suggest that RR/RX ACTN3 and ACE DD genotypes may benefit athletes in activities that require strength and speed, while II ACE genotype may benefit athletes in endurance activities. This information could help coaches to plan the training session to improve the athletes' performance.

  8. [Comparison of clinical assessment and invasive evaluation of hemodynamic parameters in septic shock].

    PubMed

    Vucić, N; Pilas, V

    1995-06-01

    The authors compare, in this prospective study, the accuracy of their own clinical assessment of hemodynamic parameters and severity of disease with the findings obtained by right heart catheterization in 50 patients with septic shock. The purpose of the study was to determine whether Swan-Ganz catheter insertion was necessary in all patients with septic shock. As soon as the diagnosis was established, the value of pulmonary capillary wedge pressure was estimated, as well as presence or absence of pathological uptake/supply dependency in all patients. The latter is an excellent indicator of severity of disease. The accurate assessment was noted in 27 (54%) patients (1. investigator), and in 30 (60%) patients (2. investigator). The sensitivity of detection of pathological uptake/supply dependency amounted to 53% and 65%; specificity was 73% and 79%, respectively. The therapy was altered in 21 patients (42%) after catheter insertion. The results were tested with chi2-test (p < 0.01). The findings of this study warrant catheter insertion in patients with septic shock.

  9. Hemodynamic changes and retrograde flow in LVAD failure.

    PubMed

    Giridharan, Guruprasad A; Koenig, Steven C; Soucy, Kevin G; Choi, Young; Pirbodaghi, Tohid; Bartoli, Carlo R; Monreal, Gretel; Sobieski, Michael A; Schumer, Erin; Cheng, Allen; Slaughter, Mark S

    2015-01-01

    In the event of left ventricular assist device (LVAD) failure, we hypothesized that rotary blood pumps will experience significant retrograde flow and induce adverse physiologic responses. Catastrophic LVAD failure was investigated in computer simulation with pulsatile, axial, and centrifugal LVAD, mock flow loop with pulsatile (PVAD) and centrifugal (ROTAFLOW), and healthy and chronic ischemic heart failure bovine models with pulsatile (PVAD), axial (HeartMate II), and centrifugal (HVAD) pumps. Simulated conditions were LVAD "off" with outflow graft clamped (baseline), LVAD "off" with outflow graft unclamped (LVAD failure), and LVAD "on" (5 L/min). Hemodynamics (aortic and ventricular blood pressures, LVAD flow, and left ventricular volume), echocardiography (cardiac volumes), and end-organ perfusion (regional blood flow microspheres) were measured and analyzed. Retrograde flow was observed with axial and centrifugal rotary pumps during LVAD failure in computer simulation (axial = -3.4 L/min, centrifugal = -2.8 L/min), mock circulation (pulsatile = -0.1 L/min, centrifugal = -2.7 L/min), healthy (pulsatile = -1.2 ± 0.3 L/min, axial = -2.2 ± 0.2 L/min, centrifugal = -1.9 ± 0.3 L/min), and ischemic heart failure (centrifugal = 2.2 ± 0.7 L/min) bovine models for all test conditions (p < 0.05). Differences between axial and centrifugal LVAD were statistically indiscernible. Retrograde flow increased ventricular end-systolic and end-diastolic volumes and workload, and decreased myocardial and end-organ perfusion during LVAD failure compared with baseline, LVAD support, and pulsatile LVAD failure.

  10. Clinical deterioration following middle cerebral artery hemodynamic changes after intravenous thrombolysis for acute ischemic stroke.

    PubMed

    Baizabal-Carvallo, José Fidel; Alonso-Juarez, Marlene; Samson, Yves

    2014-02-01

    Little information exists regarding what occurs in the affected artery in the days after acute ischemic stroke and its impact in the outcome. We sought to determine the hemodynamic evolution and correlated this evoution with clinical outcome in stroke patients treated with intravenous thrombolysis. Using serial transcranial Doppler ultrasound (TCD) on days 1 (TCD1), 3 to 6 (TCD2), and 7 to 10 (TCD3) after stroke, we determined the hemodynamics in the affected artery by means of the thrombolysis in brain ischemia (TIBI) score and compared this with clinical outcome (National Institutes of Health Stroke Scale [NIHSS] score) and functional outcome (modified Rankin Scale score) at discharge and at 3 months. Thirty-four patients were studied. There were 24 men with a mean (± SD) age of 72.9 ± 16.2 years. The mean time from stroke onset to the administration of intravenous tissue plasminogen activator was 181 ± 54.4 minutes, and the mean NIHSS score at admission was 16.9 ± 9. Hemodynamic changes were observed in 23 (68%) patients, including improvement in 17 (50%) patients and worsening in 6 (18%) patients within the first 10 days poststroke. Clinical deterioration (NIHSS ≥4 points) was timely associated with hemodynamic deterioration in 3 cases. Patients achieving full recanalization at TCD3 had better mRS scores at 3 months (4 v 3; P = .02). Hemodynamic changes in the affected artery occurred in about two-thirds of patients within the first 10 days after receiving intravenous thrombolysis; 18% had hemodynamic deterioration, which was associated with clinical worsening in half of these cases. Copyright © 2014 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  11. [Comparison of preoperative and postoperative hemodynamic parameters in replacement or reconstruction of the mitral valve in ischemic dilated cardiomyopathy].

    PubMed

    Mijatov, M; Jonjev, Z; Konstantinović, Z; Golubović, M; Radovanović, N

    2000-01-01

    Ischemic mitral insufficiency is a clinical syndrome described as a consequence of the coronary artery disease where the basic problem is blood regurgitation between the left ventricle and left atrium following mitral annulus dilatation. Mitral regurgitation occurs in different degrees during the natural evolution of the ischemic heart disease. The main reason for the existence of mitral regurgitation is global deterioration in the left ventricle geometry as a consequence of myocardial infarction or/and left ventricle dilatation. Surgical correction of this problem is possible by simultaneous correction of mitral insufficiency (repair or replacement) and complete myocardial revascularisation. Complete hemodynamic monitoring was followed by Swan-Ganz catheter including: central venous pressure, mean pulmonary artery pressure, pulmonary capillary wedge pressure, cardiac output, cardiac index and pulmonary vascular resistance. All surgical procedures were performed in extracorporeal circulation (ECC) with membrane oxygenator using moderate systemic hypothermia and transseptal surgical approach to mitral valve. Hemodynamic parameters were followed before and after ECC, immediately after surgery and during the first 48 hours after operation in the intensive care unit. In 88 patients posterior semicircular annuloplasty by N. Radovanović was performed whereas in 13 patients mitral valve replacement was done. There is a great, statistically significant hemodynamic improvement after the surgical procedure and during the continuous 48 hours monitoring in the intensive care unit no matter if mitral repair or replacement was done. No statistically significant difference was recorded between these two groups considering that the hemodynamic improvement is very similar. Simultaneous surgical procedures, including myocardial revascularization, mitral and usually consecutive tricuspid insufficiency correction, are a very common surgical problem with higher operative risk than

  12. Pulmonary venous flows reflect changes in left atrial hemodynamics during mitral balloon valvotomy

    NASA Technical Reports Server (NTRS)

    Yalcin, Fatih; El-Amrousy, Mahmoud; Muderrisoglu, Haldun; Korkmaz, Mehmet; Flachskampf, Frank; Tuzcu, Murat; Garcia, Mario G.; Thomas, James D.

    2002-01-01

    Patients with mitral stenosis have usually blunted pulmonary venous (PV) flow, because of decreased mitral valve area and diastolic dysfunction. The authors compared changes in Doppler PV velocities by using transesophageal echocardiography (TEE) against hemodynamics parameters before and after mitral balloon valvotomy to observe relevance of PV velocities and endsystolic left atrial (LA) pressure-volume relationship. In 25 patients (aged 35 +/- 17 years) with mitral stenosis in sinus rhythm, changes in LA pressure and volumes were compared with PV velocities before and after valvotomy. Mitral valve area, mitral gradients, and deceleration time were obtained. Mitral valve area and mitral gradients changed from 1 +/- 0.2 cm2 and 14.6 +/- 5.4 mmHg to 1.9 +/- 0.3 cm2 and 6.3 +/- 1.7 mmHg, respectively (p<0.001). AR peak reverse flow velocity and AR duration decreased from 29 +/- 13 cm/s and 110 =/- 30 msec to 19 +/- 6 cm/s and 80 +/- 29 msec respectively (p<0.001). Transmitral Doppler E wave deceleration time decreased from 327 +/- 85 to 209 +/- 61 s and cardiac output increased from 4.2 +/- 1.0 to 5.2 +/- 1.1 L/minute (p<0.001). The changes in LA pressure were correlated with changes in S/D (r=0.57, p<0.05). The changes in endsystolic LA pressure-volume relationship were also correlated with changes in S/D (r=0.52, p<0.05). Endsystolic LA pressure-volume relationship decreased after mitral balloon valvotomy, as a result of a large decrease in pressure. PV systolic/diastolic (S/D) waves ratio reflects endsystolic LA pressure-volume relationship and may be used as another indicator of successful valvotomy.

  13. Pulmonary venous flows reflect changes in left atrial hemodynamics during mitral balloon valvotomy

    NASA Technical Reports Server (NTRS)

    Yalcin, Fatih; El-Amrousy, Mahmoud; Muderrisoglu, Haldun; Korkmaz, Mehmet; Flachskampf, Frank; Tuzcu, Murat; Garcia, Mario G.; Thomas, James D.

    2002-01-01

    Patients with mitral stenosis have usually blunted pulmonary venous (PV) flow, because of decreased mitral valve area and diastolic dysfunction. The authors compared changes in Doppler PV velocities by using transesophageal echocardiography (TEE) against hemodynamics parameters before and after mitral balloon valvotomy to observe relevance of PV velocities and endsystolic left atrial (LA) pressure-volume relationship. In 25 patients (aged 35 +/- 17 years) with mitral stenosis in sinus rhythm, changes in LA pressure and volumes were compared with PV velocities before and after valvotomy. Mitral valve area, mitral gradients, and deceleration time were obtained. Mitral valve area and mitral gradients changed from 1 +/- 0.2 cm2 and 14.6 +/- 5.4 mmHg to 1.9 +/- 0.3 cm2 and 6.3 +/- 1.7 mmHg, respectively (p<0.001). AR peak reverse flow velocity and AR duration decreased from 29 +/- 13 cm/s and 110 =/- 30 msec to 19 +/- 6 cm/s and 80 +/- 29 msec respectively (p<0.001). Transmitral Doppler E wave deceleration time decreased from 327 +/- 85 to 209 +/- 61 s and cardiac output increased from 4.2 +/- 1.0 to 5.2 +/- 1.1 L/minute (p<0.001). The changes in LA pressure were correlated with changes in S/D (r=0.57, p<0.05). The changes in endsystolic LA pressure-volume relationship were also correlated with changes in S/D (r=0.52, p<0.05). Endsystolic LA pressure-volume relationship decreased after mitral balloon valvotomy, as a result of a large decrease in pressure. PV systolic/diastolic (S/D) waves ratio reflects endsystolic LA pressure-volume relationship and may be used as another indicator of successful valvotomy.

  14. Diffuse optical monitoring of hemodynamic changes in piglet brain with closed head injury

    NASA Astrophysics Data System (ADS)

    Zhou, Chao; Eucker, Stephanie A.; Durduran, Turgut; Yu, Guoqiang; Ralston, Jill; Friess, Stuart H.; Ichord, Rebecca N.; Margulies, Susan S.; Yodh, Arjun G.

    2009-05-01

    We used a nonimpact inertial rotational model of a closed head injury in neonatal piglets to simulate the conditions following traumatic brain injury in infants. Diffuse optical techniques, including diffuse reflectance spectroscopy and diffuse correlation spectroscopy (DCS), were used to measure cerebral blood oxygenation and blood flow continuously and noninvasively before injury and up to 6 h after the injury. The DCS measurements of relative cerebral blood flow were validated against the fluorescent microsphere method. A strong linear correlation was observed between the two techniques (R=0.89, p<0.00001). Injury-induced cerebral hemodynamic changes were quantified, and significant changes were found in oxy- and deoxy-hemoglobin concentrations, total hemoglobin concentration, blood oxygen saturation, and cerebral blood flow after the injury. The diffuse optical measurements were robust and also correlated well with recordings of vital physiological parameters over the 6-h monitoring period, such as mean arterial blood pressure, arterial oxygen saturation, and heart rate. Finally, the diffuse optical techniques demonstrated sensitivity to dynamic physiological events, such as apnea, cardiac arrest, and hypertonic saline infusion. In total, the investigation corraborates potential of the optical methods for bedside monitoring of pediatric and adult human patients in the neurointensive care unit.

  15. Method to observe hemodynamic and metabolic changes during hemodiafiltration therapy with exercise.

    PubMed

    Cadena, Miguel; Pérez-Grovas, Héctor; Flores, Pedro; Azpiroz, Joaquín; Borja, Gisella; Medel, Humberto; Rodriguez, Fausto; Flores, Francisco

    2010-01-01

    Intradyalitic exercise programas are important to improve patient's hemodynamic stability. Blood pressure and metabolic changes are correlated when heat accumulation is due to increment of the body core temperature (+1.0 °C). However, increase in temperature could be controlled by lowering dialysate's temperature using two main modalities techniques (isothermic and thermoneural) with different patient's thermal balance consequences, not yet well studied. In this work, a new method to observe the main physiological parameters (hearth rate variability (HRV), blood pressure, BTM dialysate temperature control and substrate utilization by indirect calorimtery) which are involved in hemodiafitration (HDF), are displayd. An experiment was carried out in a group of 5 patients waiting kidney transplant. In each patient, EE was assessed as well as the HRV during isothermic and thermoneutral modalities as a manner of cross and prospective study (a) at before therapy, (b) during therapy and (c) at the end of the HDF therapy. Power extraction was also measured by a BTM (Blood Temperature Monitor from Fresenius Inc), in order to determine how the dialysate temperature was controlled. The results showed important method's advantages which place the BTM performance as unstable control system with the possibility to produce undesirable HRV changes as the vagotonical response. However more patient cases are needed in order to identify the real advantage of this new method.

  16. Diffuse optical monitoring of hemodynamic changes in piglet brain with closed head injury

    PubMed Central

    Zhou, Chao; Eucker, Stephanie A.; Durduran, Turgut; Yu, Guoqiang; Ralston, Jill; Friess, Stuart H.; Ichord, Rebecca N.; Margulies, Susan S.; Yodh, Arjun G.

    2011-01-01

    We used a nonimpact inertial rotational model of a closed head injury in neonatal piglets to simulate the conditions following traumatic brain injury in infants. Diffuse optical techniques, including diffuse reflectance spectroscopy and diffuse correlation spectroscopy (DCS), were used to measure cerebral blood oxygenation and blood flow continuously and noninvasively before injury and up to 6 h after the injury. The DCS measurements of relative cerebral blood flow were validated against the fluorescent microsphere method. A strong linear correlation was observed between the two techniques (R = 0.89, p < 0.00001). Injury-induced cerebral hemodynamic changes were quantified, and significant changes were found in oxy- and deoxy-hemoglobin concentrations, total hemoglobin concentration, blood oxygen saturation, and cerebral blood flow after the injury. The diffuse optical measurements were robust and also correlated well with recordings of vital physiological parameters over the 6-h monitoring period, such as mean arterial blood pressure, arterial oxygen saturation, and heart rate. Finally, the diffuse optical techniques demonstrated sensitivity to dynamic physiological events, such as apnea, cardiac arrest, and hypertonic saline infusion. In total, the investigation corraborates potential of the optical methods for bedside monitoring of pediatric and adult human patients in the neurointensive care unit. PMID:19566308

  17. Biochemical and hemodynamic changes in normal subjects during acute and rigorous bed rest and ambulation

    NASA Astrophysics Data System (ADS)

    Zorbas, Yan G.; Kakurin, Vassily J.; Afonin, Victor B.; Yarullin, Vladimir L.

    2002-06-01

    Rigorous bed rest (RBR) induces significant biochemical and circulatory changes. However, little is known about acute rigorous bed rest (ARBR). Measuring biochemical and circulatory variables during ARBR and RBR the aim of this study was to establish the significance of ARBR effect. Studies were done during 3 days of a pre-bed rest (BR) period and during 7 days of ARBR and RBR period. Thirty normal male individuals aged, 24.1±6.3 years were chosen as subjects. They were divided equally into three groups: 10 subjects placed under active control conditions served as unrestricted ambulatory control subjects (UACS), 10 subjects submitted to an acute rigorous bed rest served as acute rigorous bed rested subjects (ARBRS) and 10 subjects submitted to a rigorous bed rest served as rigorous bed rested subjects (RBRS). The UACS were maintained under an average running distance of 9.7 km day -1. For the ARBR effect simulation, ARBRS were submitted abruptly to BR for 7 days. They did not have any prior knowledge of the exact date and time when they would be asked to confine to RBR. For the RBR effect simulation, RBRS were subjected to BR for 7 days on a predetermined date and time known to them right away from the start of the study. Plasma renin activity (PRA), plasma cortisol (PC), plasma aldosterone (PA), plasma and urinary sodium (Na) and potassium (K) levels, heart rate (HR), cardiac output (CO), and arterial blood pressure (ABP) increased significantly, and urinary aldosterone (UA), stroke volume (SV) and plasma volume (PV) decreased significantly ( p<0.05) in ARBRS and RBRS as compared with their pre-BR values and the values in UACS. Electrolyte, hormonal and hemodynamic responses were significantly ( p<0.05) greater and occurred significantly faster ( p<0.05) during ARBR than RBR. Parameters change insignificantly ( p>0.05) in UACS compared with pre-BR control values. It was concluded that, the more abruptly muscular activity is restricted in experimental subjects

  18. The dynamics of autonomic nervous system activity and hemodynamic changes in pregnant women.

    PubMed

    Balajewicz-Nowak, Marta; Furgala, Agata; Pitynski, Kazimierz; Thor, Piotr; Huras, Hubert; Rytlewski, Krzysztof

    2016-01-01

    The purpose of this research was to assess the dynamics of autonomic nervous system(ANS) and hemodynamic activity changes during uncomplicated pregnancy. We enrolled 36 pregnant women (mean age 29 ± 4.8 years) and a control group of 10 non-pregnant women (mean age 25.9 ± 0.88 years). The examination was performed in the 1st, 2nd, and 3rd trimester. Continuous registration of BP, ECG, and cardioimpedance was performed with Task Force Monitor 3040i. ANS activity was measured using the following parameters: HRV, BPV, BRS at rest, and in response to autonomic tests. Compared to the 1st trimester, an increase in HR (73 vs. 92 bpm; p < 0.001) and mean BP (80 vs. 85 mmHg, p < 0.01) was observed in the 3rd trimester. In the 1st trimester, the BRS of pregnant women was insignificantly higher than in the controls (24.8 vs. 22.3 ms/mmHg); subsequently, it decreased significantly, to 13.4 ms/mmHg in the 3rd trimester (p = 0.0004). An increase in nLF (39.57 ± 13.75 vs. 58.73 ± 15.55; p = 0.001) and LF/HF ratio (1.03 ± 0.76 vs. 1.85 ± 0.8; p < 0.00002) was revealed in HRV analysis conducted in the 3rd trimester, as compared to the 1st tri- mester, along with a decrease in nHF (60.43 ± 13.71 vs. 41.26 ± 15.55; p < 0.001). An increase in LF/HF-sBPV (1.05 ± 0.48 vs. 1.58 ± 0.44; p = 0.01) was recorded in BPV analysis at rest in the 3rd trimester as compared to the respective 1st trimester value. Our findings suggest that pregnancy is associated with dynamic changes in autonomic balance, namely doubled dominance of the sympathetic component. Hypervolemia seems the major factor responsible for autonomic and hemodynamic changes observed during pregnancy, as it causes an increase in BP and simultaneous decrease in BRS.

  19. Evaluation of hemodynamics changes during interventional stent placement using Doppler optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Vuong, Barry; Genis, Helen; Wong, Ronnie; Ramjist, Joel; Jivraj, Jamil; Farooq, Hamza; Sun, Cuiru; Yang, Victor X. D.

    2015-03-01

    Carotid atherosclerosis is a critical medical concern that can lead to ischemic stroke. Local hemodynamic patterns have also been associated with the development of atherosclerosis, particularly in regions with disturbed flow patterns such as bifurcations. Traditionally, this disease was treated using carotid endarterectomy, however recently there is an increasing trend of carotid artery stenting due to its minimally invasive nature. It is well known that this interventional technique creates changes in vasculature geometry and hemodynamic patterns due to the interaction of stent struts with arterial lumen, and is associated with complications such as distal emboli and restenosis. Currently, there is no standard imaging technique to evaluate regional hemodynamic patterns found in stented vessels. Doppler optical coherence tomography (DOCT) provides an opportunity to identify in vivo hemodynamic changes in vasculature using high-resolution imaging. In this study, blood flow profiles were examined at the bifurcation junction in the internal carotid artery (ICA) in a porcine model following stent deployment. Doppler imaging was further conducted using pulsatile flow in a phantom model, and then compared to computational fluid dynamics (CFD) simulation of a virtual bifurcation to assist with the interpretation of emphin vivo results.

  20. [Early predictive value of hemodynamic parameters during fluid resuscitation in patients with sepsis shock].

    PubMed

    Chen, Wei; Zang, Xuefeng; Niu, Suping; Lyu, Chao; Zhao, Lei; Sheng, Bo; Gu, Xuyun; Zhang, Jingshu

    2015-01-01

    To investigate the short term predictive value of hemodynamic parameters during fluid resuscitation in patients with septic shock. Data of 76 patients with septic shock admitted to Department of Critical Care Medicine of Beijing Shijitan Hospital from January 2013 to October 2014 were retrospectively analyzed. The hemodynamic parameters were monitored by pulse indicator continuous cardiac output ( PiCCO ), including mean arterial pressure ( MAP ), stroke volume index ( SVI ), cardiac index ( CI ), global ejection fraction ( GEF ), global end diastolic volume index ( GEDVI ), intrathoracic blood volume index ( ITBVI ), extravascular lung water index ( EVLWI ), systemic vascular resistance index ( SVRI ), and pulmonary vascular permeability index ( PVPI ). They were recorded before and 6 hours after fluid resuscitation. According to the prognosis on the 7th day, the patients were divided into survival group ( n = 42 ) and death group ( n = 34 ). The PiCCO records between two groups were compared and a receiver operating characteristic ( ROC ) curve for predicting the outcome was plotted to find the cut-off point value for each PiCCO record before and 6 hours after fluid resuscitation.The factors for predicting 7-day prognosis of patients with septic shock were analyzed by multivariate logistic regression analysis. (1) Compared with those before fluid resuscitation, EVLWI and PVPI were significantly decreased at 6 hours after fluid resuscitation in the survival group [ EVLWI ( mL/kg ): 7.33±1.72 vs. 9.07±2.81, PVPI: 1.39±0.34 vs. 1.74±0.50, both P<0.01 ] but they were significantly increased in the death group [ EVLWI ( mL/kg ): 12.62±3.58 vs. 8.97±2.74, PVPI: 2.36±0.81 vs. 1.73±0.60, both P<0.01 ], and MAP in the death group decreased after fluid resuscitation [ MAP ( mmHg, 1 mmHg = 0.133 kPa ): 70.53±12.12 vs. 77.06±13.48, P<0.01 ]. (2)ROC curve showed that the area under ROC curve ( AUC ) of EVLWI at 6 hours after fluid resuscitation was 0.914, cut

  1. Changes in hemodynamics and light scattering during cortical spreading depression

    NASA Astrophysics Data System (ADS)

    Li, Pengcheng; Yang, Yuanyuan; Luo, Qingming

    2005-01-01

    Cortical spreading depression (CSD) has been known to play an important role in the mechanism of migraine, stroke and brain injure. Optical imaging of intrinsic signals has been shown a powerful method for characterizing the spatial and temporal pattern of the propagation of CSD. However, the possible physiological mechanisms underlying the intrinsic optical signal (IOS) during CSD still remain incompletely understood. In this study, a spectroscopic recording of the change in optical intrinsic signal during CSD was performed and an analysis method based on the modified Beer-Lambert law was used to estimate the changes in the concentration of HbO2 and Hb, and changes in light scattering from the spectra data. The CSD were induced by pinprick in 10 α-chloralose/urethane anesthetized Sprague-Dawley rats. In all experiments, four-phasic changes in optical reflectance were observed at 450 nm ~ 570 nm, and triphasic changes in optical reflectance were observed in the range of 570 nm ~750 nm. But at 750 nm ~ 850 nm, only biphasic changes of optical signal were detected. Converting the spectra data to the changes in light scattering and concentration of Hb and HbO2, we found that the CSD induced an initial increase in concentration of HbO2 (amplitude: 9.0+/-3.7%), which was 26.2+/-18.6 s earlier than the onset of increase of Hb concentration. Furthermore, the concentration of HbO2 showed a four-phasic change, whereas the concentration of Hb only showed a biphasic change. For the changes in light scattering during CSD, a triphasic change was observed.

  2. Clinical study of hemodynamic changes during extraction in controlled hypertensive patients.

    PubMed

    Silvestre, Francisco-Javier; Salvador-Martínez, Isabel; Bautista, Daniel; Silvestre-Rangil, Javier

    2011-05-01

    To evaluate the efficacy and safety of the vasoconstrictor used in local anesthesia during dental extraction in controlled hypertensive patients. A prospective observational study was carried out in hypertensive patients (n=97) with a mean age of 60.45±9.60 years. The following parameters were monitored at three different timepoints (before the procedure, 3 minutes after local anesthesia infiltration, and 3 minutes after the operation): blood pressure (diastolic and systolic), heart rate, and oxygen saturation. Anesthesia (1-3 carpules) was provided in the form of articaine with 4% epinephrine as vasoconstrictor in one group, while another group received 3% mepivacaine without vasoconstrictor. All patients presented primary hypertension (n=97)(grade I in 57.7% of the cases and grade II in 42.3%). The most widely used antihypertensive drugs were angiotensin II receptor antagonists (ARA II). The only significant differences observed corresponded to systolic blood pressure measured before and after dental extraction in the group of hypertensive patients anesthetized with vasoconstrictor. In procedures such as dental extraction, no significant hemodynamic changes in well controlled hypertensive patients are seen attributable to anesthetic use with a vasoconstrictor, when fewer than three local anesthetic carpules are administered.

  3. Comparison of Dexmedetomidine and Remifentanil on Airway Reflex and Hemodynamic Changes during Recovery after Craniotomy

    PubMed Central

    Kim, Hyunzu; Min, Kyeong Tae; Lee, Jeong Rim; Ha, Sang Hee; Lee, Woo Kyung; Seo, Jae Hee

    2016-01-01

    Purpose During emergence from anesthesia for a craniotomy, maintenance of hemodynamic stability and prompt evaluation of neurological status is mandatory. The aim of this prospective, randomized, double-blind study was to compare the effects of dexmedetomidine and remifentanil on airway reflex and hemodynamic change in patients undergoing craniotomy. Materials and Methods Seventy-four patients undergoing clipping of unruptured cerebral aneurysm were recruited. In the dexmedetomidine group, patients were administered dexmedetomidine (0.5 µg/kg) for 5 minutes, while the patients of the remifentanil group were administered remifentanil with an effect site concentration of 1.5 ng/mL until endotracheal extubation. The incidence and severity of cough and hemodynamic variables were measured during the recovery period. Hemodynamic variables, respiration rate, and sedation scale were measured after extubation and in the post-anesthetic care unit (PACU). Results The incidence of grade 2 and 3 cough at the point of extubation was 62.5% in the dexmedetomidine group and 53.1% in the remifentanil group (p=0.39). Mean arterial pressure (p=0.01) at admission to the PACU and heart rate (p=0.04 and 0.01, respectively) at admission and at 10 minutes in the PACU were significantly lower in the dexmedetomidine group. Respiration rate was significantly lower in the remifentanil group at 2 minutes (p<0.01) and 5 minutes (p<0.01) after extubation. Conclusion We concluded that a single bolus of dexmedetomidine (0.5 µg/kg) and remifentanil infusion have equal effectiveness in attenuating coughing and hemodynamic changes in patients undergoing cerebral aneurysm clipping; however, dexmedetomidine leads to better preservation of respiration. PMID:27189295

  4. Acute changes in systemic hemodynamics and serum vasopressin after complete cervical spinal cord injury in piglets.

    PubMed

    Zahra, Michael; Samdani, Amer; Piggott, Kurt; Gonzalez-Brito, Manuel; Solano, Juan; De Los Santo, Roosevelt; Buitrago, Juan C; Alam, Farid; He, Dansha; Gaughan, John P; Betz, Randal; Dietrich, Dalton; Kuluz, John

    2010-08-01

    Spinal cord injury (SCI) produces acute hemodynamic alterations through disruption of sympathetic output of the autonomic nervous system and places individuals with SCI at high risk of secondary ischemic insult to the spinal cord as well as to other organs. The purpose of this study was to examine hemodynamics and serum vasopressin concentration in the acute period following complete cervical SCI in piglets. We developed a new model of traumatic complete cervical SCI in piglets and measured acute hemodynamic variables and serum arginine vasopressin (AVP) concentrations at baseline and for 4 h after SCI under fentanyl anesthesia. Complete cervical SCI caused an immediate tachycardia which lasted for approximately 1 h, immediate hypotension which was sustained for the 4-h duration of the study, decreases in both systemic and pulmonary vascular resistance, and a compensatory increase in cardiac output, which resulted initially from an increase in heart rate (HR) but was later sustained after resolution of tachycardia by an increase in cardiac stroke volume. Serum AVP concentration increased significantly after SCI and did not change in the control group. Neurogenic shock did not occur due to the robust increase in cardiac output and cardiac stroke volume. Complete cervical SCI produces hemodynamic alterations consistent with the withdrawal of sympathetic tone. Although mean arterial pressure (MAP) decreased significantly after SCI, the increase in serum vasopressin may have played a role in maintaining blood pressure and preventing circulatory collapse, a complication which is encountered frequently in patients with cervical and upper thoracic SCI.

  5. Novel Mutations in BMPR2, ACVRL1 and KCNA5 Genes and Hemodynamic Parameters in Patients with Pulmonary Arterial Hypertension

    PubMed Central

    Pousada, Guillermo; Baloira, Adolfo; Vilariño, Carlos; Cifrian, Jose Manuel; Valverde, Diana

    2014-01-01

    Background Pulmonary arterial hypertension (PAH) is a rare and progressive vascular disorder characterized by increased pulmonary vascular resistance and right heart failure. The aim of this study was to analyze the Bone Morphogenetic Protein Receptor 2 (BMPR2), Activin A type II receptor like kinase 1 (ALK1/ACVRL1) and potassium voltage-gated channel, shakerrelated subfamily, member 5 (KCNA5) genes in patients with idiopathic and associated PAH. Correlation among pathogenic mutations and clinical and functional parameters was further analyzed. Methods and Results Forty one patients and fifty controls were included in this study. Analysis of BMPR2, ACVRL1 and KCNA5 genes was performed by polymerase chain reaction (PCR) and direct sequencing. Fifty one nucleotide changes were detected in these genes in 40 of the 41 patients; only 22 of these changes, which were classified as pathogenic, have been detected in 21 patients (51.2%). Ten patients (62.5%) with idiopathic PAH and 10 (40%) with associated PAH showed pathogenic mutations in some of the three genes. Several clinical and hemodynamics parameters showed significant differences between carriers and non-carriers of mutations, being more severe in carriers: mean pulmonary artery pressure (p = 0.043), pulmonary vascular resistence (p = 0.043), cardiac index (p = 0.04) and 6 minute walking test (p = 0.02). This differences remained unchanged after adjusting for PAH type (idiopathic vs non idiopathic). Conclusions Pathogenic mutations in BMPR2 gene are frequent in patients with idiopathic and associated PAH group I. Mutations in ACVRL1 and KCNA5 are less frequent. The presence of these mutations seems to increase the severity of the disease. PMID:24936649

  6. Effect of irrigation fluid temperature on core temperature and hemodynamic changes in transurethral resection of prostate under spinal anesthesia

    PubMed Central

    Singh, Rajeev; Asthana, Veena; Sharma, Jagdish P.; Lal, Shobha

    2014-01-01

    Background: Hypothermia is a frequent observation in elderly males undergoing transurethral resection of prostate (TURP) under spinal anesthesia. The use of irrigating fluids at room temperature results in a decrease body temperature. Warmed irrigating solutions have shown to reduce heat loss and the resultant shivering. Such investigation was not much tried in low resource settings. Aim: To compare the resultant change in core temperature and hemodynamic changes among patients undergoing TURP surgery under spinal anesthesia using warm and room temperature irrigation fluids. Settings and Design: Randomized prospective study at a tertiary care center. Methods: This study was conducted on 40 male patients aged 50-85 years undergoing TURP under spinal anesthesia. Of which, 20 patients received irrigation fluid at room temperature 21°C and 20 patients received irrigation fluid at 37°C after random allocation. Core temperatures and hemodynamic parameters were assessed in all patients at preoperative, intra-operative, and postoperative periods. Intra-operative shivering was also noted in both groups. Statistical Analysis: Unpaired and Paired Student's t-test. Results: For patients who underwent irrigation with fluid at room temperature Core temperature drop from 36.97°C in preoperative to 34.54°C in postoperative period with an effective difference of 2.38°C. Among patients who received warmed irrigation fluid at 37°C had core temperature drop from 36.97°C to 36.17°C and the effect of fall was 0.8°C. This difference was statistically significant (P < 0.001). Shivering of Grades 1 and 2 was observed in nine patients, of Group 1 while only three patients had Grades 1 and 2 shivering in Group 2. The hemodynamic parameters were similar in the two groups and did not reach significant difference. Conclusion: Use of warm irrigation fluid during TURP reduces the risk of perioperative hypothermia and shivering. PMID:25886228

  7. Hemodynamic changes comparing 2% lidocaine and 4% articaine with epinephrine 1: 100,000 in lower third molar surgery.

    PubMed

    de Morais, Hécio Henrique Araújo; de Santana Santos, Thiago; da Costa Araújo, Fábio Andrey; de Freitas Xavier, Ruth Lopes; Vajgel, André; de Holanda Vasconcellos, Ricardo José

    2012-07-01

    An increase in blood pressure during dental treatment has been investigated with regard to potential medical risks since previous studies suggest that dental procedures may cause stress to the patient and, consequently, the cardiovascular system. The aim of the present study was to analyze hemodynamic changes following the administration of either 2% lidocaine (L100) or 4% articaine (A100) (both with epinephrine 1:100,000) in the surgical removal of symmetrically positioned lower third molars. A prospective, randomized, double-blind, clinical trial was carried out involving 47 patients. Each patient underwent 1 surgery at each of 2 appointments--one under local anesthesia with L100 and the other with A100. The following parameters were assessed at 4 different times: systolic, diastolic, and mean blood pressure; heart rate; oxygen saturation; rate pressure product; and pressure rate quotient. No hypertensive peak was observed in systolic, diastolic, and mean blood pressure at any evaluation time. Moreover, the type of anesthetic solution did not affect diastolic blood pressure, heart rate, or oxygen saturation during the surgeries. The pressure rate quotient was the only parameter to exhibit statistically significant differences between groups at different evaluation times (P < 0.05). The hemodynamic parameters evaluated in third molar surgery with 2% lidocaine and 4% articaine (both with epinephrine 1:100,000) did not show significant differences.

  8. Cerebral hemodynamic changes and electroencephalography during carotid endarterectomy

    SciTech Connect

    Algotsson, L.; Messeter, K.; Rehncrona, S.; Skeidsvoll, H.; Ryding, E. )

    1990-05-01

    Some patients undergoing endarterectomy for occlusive carotid artery disease run a risk of brain ischemia during cross-clamping of the artery. The present study of 15 patients was undertaken to evaluate changes in cerebral blood flow (CBF), as measured with an intravenous (IV) tracer (133Xenon) technique, and to relate CBF changes to changes in the electroencephalogram (EEG). CBF was measured before and after induction of anesthesia, during cross-clamping of the carotid artery, after release of the clamps, and at 24 hours after the operation. All the patients were anesthetized with methohexitone, fentanyl, and nitrous oxide and oxygen. EEG was continuously recorded during the operation. Carotid artery shunts were not used. In 8 patients, cross-clamping of the carotid artery did not influence the EEG. In this group of patients, induction of anesthesia caused a 38% decrease in CBF, which presumably reflects the normal reaction to the anesthetic agent given. There were no further changes in CBF during cross-clamping. In 7 patients, the EEG showed signs of deterioration during the intraoperative vascular occlusion. In these patients, anesthesia did not cause any CBF change, whereas cross-clamping the artery induced a 33% decrease in CBF. In individual patients, the severity of EEG changes correlated with the decrease in CBF. The absence of a change in CBF by anesthesia and a decrease due to cross-clamping of the carotid artery may be explained by the presence of a more advanced cerebrovascular disease and an insufficiency to maintain CBF during cross-clamping.

  9. Immediate effects of chest physiotherapy on hemodynamic, metabolic, and oxidative stress parameters in subjects with septic shock.

    PubMed

    dos Santos, Rafael S; Donadio, Márcio V F; da Silva, Gabriela V; Blattner, Clarissa N; Melo, Denizar A S; Nunes, Fernanda B; Dias, Fernando S; Squizani, Eamim D; Pedrazza, Leonardo; Gadegast, Isabella; de Oliveira, Jarbas R

    2014-09-01

    Septic shock presents as a continuum of infectious events, generating tissue hypoxia and hypovolemia, and increased oxidative stress. Chest physiotherapy helps reduce secretion, improving dynamic and static compliance, as well as improving secretion clearance and preventing pulmonary complications. The purpose of this study was to evaluate the immediate effect of chest physiotherapy on hemodynamic, metabolic, inflammatory, and oxidative stress parameters in subjects in septic shock. We conducted a quasi-experimental study in 30 subjects in septic shock, who underwent chest physiotherapy, without associated heart diseases and with vasopressors < 0.5 μg/kg/min. Venous and arterial blood gases, clinical and hemodynamic data, inflammatory data, lactate, and oxidative stress were evaluated before and 15 min after physiotherapy. Thirty subjects with a mean age of 61.8 ± 15.9 y and Sequential Organ Failure Assessment of 8 (range 6-10) were included. Chest physiotherapy caused a normalization of pH (P = .046) and P(aCO2) (P = .008); reduction of lactate (P = .001); and an increase in P(aO2) (P = .03), arterial oxygen saturation (P = .02), and P(aO2)/F(IO2) (P = .034), 15 min after it was applied. The results indicate that chest physiotherapy has immediate effects, improving oxygenation and reducing lactate and oxidative damage in subjects in septic shock. However, it does not cause alterations in the inflammatory and hemodynamic parameters. Copyright © 2014 by Daedalus Enterprises.

  10. Prevention of hemodynamic and vascular albumin filtration changes in diabetic rats by aldose reductase inhibitors.

    PubMed

    Tilton, R G; Chang, K; Pugliese, G; Eades, D M; Province, M A; Sherman, W R; Kilo, C; Williamson, J R

    1989-10-01

    This study investigated hemodynamic changes in diabetic rats and their relationship to changes in vascular albumin permeation and increased metabolism of glucose to sorbitol. The effects of 6 wk of streptozocin-induced diabetes and three structurally different inhibitors of aldose reductase were examined on 1) regional blood flow (assessed with 15-microns 85Sr-labeled microspheres) and vascular permeation by 125I-labeled bovine serum albumin (BSA) and 2) glomerular filtration rate (assessed by plasma clearance of 57Co-labeled EDTA) and urinary albumin excretion (determined by radial immunodiffusion assay). In diabetic rats, blood flow was significantly increased in ocular tissues (anterior uvea, posterior uvea, retina, and optic nerve), sciatic nerve, kidney, new granulation tissue, cecum, and brain. 125I-BSA permeation was increased in all of these tissues except brain. Glomerular filtration rate and 24-h urinary albumin excretion were increased 2- and 29-fold, respectively, in diabetic rats. All three aldose reductase inhibitors completely prevented or markedly reduced these hemodynamic and vascular filtration changes and increases in tissue sorbitol levels in the anterior uvea, posterior uvea, retina, sciatic nerve, and granulation tissue. These observations indicate that early diabetes-induced hemodynamic changes and increased vascular albumin permeation and urinary albumin excretion are aldose reductase-linked phenomena. Discordant effects of aldose reductase inhibitors on blood flow and vascular albumin permeation in some tissues suggest that increased vascular albumin permeation is not entirely attributable to hemodynamic changes. We hypothesize that 1) increases in blood flow may reflect impaired contractile function of smooth muscle cells in resistance arterioles and 2) increases in vascular 125I-BSA permeation and urinary albumin excretion reflect impaired vascular barrier functional integrity in addition to increased hydraulic conductance secondary to

  11. The effect of bariatric surgery on the retrobulbar flow hemodynamic parameters in patients with obesity: color Doppler evaluation.

    PubMed

    Çekiç, Bülent; Doğan, Berna; Toslak, Iclal Erdem; Doğan, Uğur; Sağlık, Semih; Erol, Muhammed Kazım

    2017-07-31

    To evaluate the effect of weight loss on the retrobulbar hemodynamics in patients who had undergone bariatric surgery for obesity using color Doppler ultrasound (CDU) and to evaluate correlations with intraocular pressure (IOP) changes measured using Goldman applanation tonometry. Thirty-two patients were included in this prospective study. Body mass index (BMI), IOP measurements, and retrobulbar CDU examination were performed on all individuals 6 months before and after bariatric surgery. The preoperative mean BMI value was 48.8 ± 2.27 kg/m(2), and mean IOP value was 18.2 ± 2.06 mmHg. At 6 months postoperatively, mean BMI and IOP were 36.28 ± 5.41 kg/m(2) and 16.1 ± 1.81 mmHg which was statistically significantly lower than the preoperative measurements (p < 0.001). In the comparison of pre- and postoperative orbital CDU value, the preoperative OA PSV (30.16 ± 5.31 cm/s) and OA EDV (10.93 ± 3.04) values were significantly lower than the postoperative OA PSV (36.21 ± 5.56) and OA EDV (12.84 ± 3.38) values (p < 0.001 and p < 0.05, respectively). A significant correlation was determined between BMI and IOP (r = -0.443; p < 0.05). Decrease in body weight resulting from bariatric surgery performed on morbid obese patients causes alterations in both IOP and retrobulbar hemodynamics. Morbidly obese patients who undergo bariatric surgery have statistically significantly lower IOP values and increase in OA Doppler parameters (PSV, EDV) than in the preoperative period, which reflects a better retrobulbar and ocular blood flow.

  12. Stress-sensitive arterial hypertension, hemodynamic changes and brain metabolites in hypertensive ISIAH rats: MRI investigation.

    PubMed

    Seryapina, A A; Shevelev, O B; Moshkin, M P; Markel, A L; Akulov, A E

    2017-03-08

    The study of early development of the arterial hypertension in association with emotional stress is of great importance for better understanding of etiolody and pathogenesis of the hypertensive disease. MRI technique was applied to evaluate the hemodynamic and brain metabolites changes in 1- and 3-Mo-old ISIAH rats (10 male rats) with stress-sensitive arterial hypertension and in control normotensive WAG rats (8 male rats). In the 3-Mo-old ISIAH rats, age-dependent increase in the blood pressure was associated with increased blood flow through the renal arteries and decreased blood flow in the lower part of abdominal aorta. The renal vascular resistance in the ISIAH rats decreased while aging, though, at both ages it remained higher than the renal vascular resistance in WAG rats. Integral metabolome portrait demonstrated that hypertension development in the ISIAH rats was associated with attenuation of excitatory and energetic activity in the prefrontal cortex, whereas in the WAG rats, the opposite age-dependent changes were observed. In contrast, in hypothalamus of 3-Mo-old ISIAH rats, an increase in energetic activity and prevalence of excitatory neurotransmitters over inhibitory was noticed. The blood flow through the main arteries showed positive correlation with glutamate and glutamine levels in hypothalamus, and negative one - with hypothalamic GABA level. The blood pressure values positively correlated with hypothalamic choline levels. Thus, the early development of the stress-sensitive hypertension in the ISIAH rats is accompanied by considerable changes both in brain metabolite ratios and in the parameters of blood flow through the main arteries. This article is protected by copyright. All rights reserved.

  13. Hemodynamic change in pulmonary vein stenosis after radiofrequency ablation: assessment with magnetic resonance angiography.

    PubMed

    Yun, Doyoung; Jung, Jung Im; Oh, Yong Seog; Youn, Ho-Joong

    2012-01-01

    We present a case of pulmonary vein (PV) stenosis after radio-frequency (RF) ablation, in which a hemodynamic change in the pulmonary artery was similar to that of congenital PV atresia on time-resolved contrast-enhanced magnetic resonance angiography (TR-MRA). A 48-year-old man underwent RF ablation due to atrial fibrillation. The patient subsequently complained of hemoptysis, dyspnea on exertion, and right chest pain. Right PV stenosis after catheter ablation was diagnosed through chest computed tomography and lung perfusion scan. Pulmonary TR-MRA revealed the pulmonary artery via systemic arterial collaterals and draining systemic collateral veins. On a velocity-encoded cine image, the flow direction of the right pulmonary artery was reversed in the diastolic phase and the left pulmonary artery demonstrated continuous forward flow throughout the cardiac cycle. These hemodynamic changes were similar to those seen in congenital unilateral PV atresia.

  14. Two-dimensional optical tomography of hemodynamic changes in a preterm infant brain

    NASA Astrophysics Data System (ADS)

    Gao, Feng; Xue, Yuan; Zhao, Huijuan; Kusaka, Takashi; Ueno, Masanori; Yamada, Yukio

    2007-08-01

    Our preliminary results on two-dimensional (2D) optical tomographic imaging of hemodynamic changes in a preterm infant brain are reported. We use the established 16-channel time-correlated single photon counting system for the detection and generalized pulse spectrum technique based algorithm for the image reconstruction. The experiments demonstrate that diffuse optical tomography may be a potent means for investigating brain functions and neural development of infant brains in the perinatal period.

  15. Effects of movement from a postural maintenance position on lumbar hemodynamic changes.

    PubMed

    Kumamoto, Tsuneo; Seko, Toshiaki; Takahashi, Yui

    2016-06-01

    [Purpose] To investigate the effects of movement from a postural maintenance position on lumbar hemodynamic changes, in order to prevent lower back pain and develop exercise therapy. [Subjects and Methods] Twenty-five healthy adults (mean age: 23.2 years) participated in the study. During flexion-extension exercise, the subjects moved their trunks gradually to a flexed position from an upright posture while sitting and standing, and then returned to and maintained an upright (re-upright) position. In the extension-flexion exercise, the subjects moved their trunks gradually from an upright posture to an extended position, and back while maintaining an upright (re-upright) position. Lumbar spinal muscle activity and hemodynamic changes were evaluated during both exercises. [Results] During the flexion and extension exercises, increased trunk-flexion angle caused increased muscle activity, decreased oxygenated hemoglobin in the multifidus muscle, and increased deoxygenated hemoglobin in the multifidus and lumbar erector spinae muscles. Moreover, the muscle activities were nearly the same in the re-upright and upright positions, and total hemoglobin also increased. [Conclusion] In both standing and sitting positions, holding the trunk in a flexed position causes ischemic hemodynamic changes in the multifidus muscle; however, the hyperemic response when returning the trunk to an extended position may improve circulation.

  16. Effects of movement from a postural maintenance position on lumbar hemodynamic changes

    PubMed Central

    Kumamoto, Tsuneo; Seko, Toshiaki; Takahashi, Yui

    2016-01-01

    [Purpose] To investigate the effects of movement from a postural maintenance position on lumbar hemodynamic changes, in order to prevent lower back pain and develop exercise therapy. [Subjects and Methods] Twenty-five healthy adults (mean age: 23.2 years) participated in the study. During flexion-extension exercise, the subjects moved their trunks gradually to a flexed position from an upright posture while sitting and standing, and then returned to and maintained an upright (re-upright) position. In the extension–flexion exercise, the subjects moved their trunks gradually from an upright posture to an extended position, and back while maintaining an upright (re-upright) position. Lumbar spinal muscle activity and hemodynamic changes were evaluated during both exercises. [Results] During the flexion and extension exercises, increased trunk-flexion angle caused increased muscle activity, decreased oxygenated hemoglobin in the multifidus muscle, and increased deoxygenated hemoglobin in the multifidus and lumbar erector spinae muscles. Moreover, the muscle activities were nearly the same in the re-upright and upright positions, and total hemoglobin also increased. [Conclusion] In both standing and sitting positions, holding the trunk in a flexed position causes ischemic hemodynamic changes in the multifidus muscle; however, the hyperemic response when returning the trunk to an extended position may improve circulation. PMID:27390450

  17. [Hemodynamic and respiratory changes in athletes during deep breath-hold diving].

    PubMed

    Gentile, C; La Scala, S

    2001-12-01

    The study analysed the hemodynamic and respiratory aspects of deep breath-hold diving. One male (59-year-old) and one female (32-year-old) subject were enrolled. They were both champion deep breath-hold divers. The dives were performed in the wet compartment of the hyperbaric chamber, first in thermoneutral (35 degrees C) and then cool (25 degrees C) water. The subjects were monitored using ECG recordings; percentage cannulation of the right radial artery using an aseptic technique. Stroke volume (SV) and cardiac output (CO) were measured using impedance cardiography (Bomed). Variations were observed in heart rhythm, cardiac output, arterial blood pressure and breathing. Both bradycardia and many hemodynamically effective dysrhythmias influenced CO, which showed a tendency to decrease in the diver in cool water. Changes in CO were caused by concomitant changes in HR as SV showed no significant variations. During breath-hold diving, a drop in intra-thoracic pressure is likely to enhance redistribution of blood from the periphery to the chest, which might distend the heart even more, contributing to dysrhythmogenesis. The observation that dysrhythmias were more frequent in cool water is in line with these concepts. Only two leading divers were recruited in this study and observed for hemodynamic and respiratory changes. However, these findings are in line with similar studies carried out by other authors.

  18. A novel low profile wireless flow sensor to monitor hemodynamic changes in cerebral aneurysm

    NASA Astrophysics Data System (ADS)

    Chen, Yanfei; Jankowitz, Brian T.; Cho, Sung Kwon; Chun, Youngjae

    2015-03-01

    A proof of concept of low-profile flow sensor has been designed, fabricated, and subsequently tested to demonstrate its feasibility for monitoring hemodynamic changes in cerebral aneurysm. The prototype sensor contains three layers, i.e., a thin polyurethane layer was sandwiched between two sputter-deposited thin film nitinol layers (6μm thick). A novel superhydrophilic surface treatment was used to create hemocompatible surface of thin nitinol electrode layers. A finite element model was conducted using ANSYS Workbench 15.0 Static Structural to optimize the dimensions of flow sensor. A computational fluid dynamics calculations were performed using ANSYS Workbench Fluent to assess the flow velocity patterns within the aneurysm sac. We built a test platform with a z-axis translation stage and an S-beam load cell to compare the capacitance changes of the sensors with different parameters during deformation. Both LCR meter and oscilloscope were used to measure the capacitance and the resonant frequency shifts, respectively. The experimental compression tests demonstrated the linear relationship between the capacitance and applied compression force and decreasing the length, width and increasing the thickness improved the sensor sensitivity. The experimentally measured resonant frequency dropped from 12.7MHz to 12.48MHz, indicating a 0.22MHz shift with 200g ( 2N) compression force while the theoretical resonant frequency shifted 0.35MHz with 50g ( 0.5N). Our recent results demonstrated a feasibility of the low-profile flow sensor for monitoring haemodynamics in cerebral aneurysm region, as well as the efficacy of the use of the surface treated thin film nitinol for the low-profile sensor materials.

  19. Relationship between angiotensin-(1-7) and angiotensin II correlates with hemodynamic changes in human liver cirrhosis

    PubMed Central

    Vilas-Boas, Walkíria Wingester; Ribeiro-Oliveira Jr, Antônio; Pereira, Regina Maria; da Cunha Ribeiro, Renata; Almeida, Jerusa; Nadu, Ana Paula; Simões e Silva, Ana Cristina; dos Santos, Robson Augusto Souza

    2009-01-01

    AIM: To measure circulating angiotensins at different stages of human cirrhosis and to further evaluate a possible relationship between renin angiotensin system (RAS) components and hemodynamic changes. METHODS: Patients were allocated into 4 groups: mild-to-moderate liver disease (MLD), advanced liver disease (ALD), patients undergoing liver transplantation, and healthy controls. Blood was collected to determine plasma renin activity (PRA), angiotensin (Ang) I, Ang II, and Ang-(1-7) levels using radioimmunoassays. During liver transplantation, hemodynamic parameters were determined and blood was simultaneously obtained from the portal vein and radial artery in order to measure RAS components. RESULTS: PRA and angiotensins were elevated in ALD when compared to MLD and controls (P < 0.05). In contrast, Ang II was significantly reduced in MLD. Ang-(1-7)/Ang II ratios were increased in MLD when compared to controls and ALD. During transplantation, Ang II levels were lower and Ang-(1-7)/Ang II ratios were higher in the splanchnic circulation than in the peripheral circulation (0.52 ± 0.08 vs 0.38 ± 0.04, P < 0.02), whereas the peripheral circulating Ang II/Ang I ratio was elevated in comparison to splanchnic levels (0.18 ± 0.02 vs 0.13 ± 0.02, P < 0.04). Ang-(1-7)/Ang II ratios positively correlated with cardiac output (r = 0.66) and negatively correlated with systemic vascular resistance (r = -0.70). CONCLUSION: Our findings suggest that the relationship between Ang-(1-7) and Ang II may play a role in the hemodynamic changes of human cirrhosis. PMID:19469002

  20. Long-Latency Reductions in Gamma Power Predict Hemodynamic Changes That Underlie the Negative BOLD Signal

    PubMed Central

    Harris, Samuel; Bruyns-Haylett, Michael; Kennerley, Aneurin; Zheng, Ying; Martin, Chris; Jones, Myles; Redgrave, Peter; Berwick, Jason

    2015-01-01

    Studies that use prolonged periods of sensory stimulation report associations between regional reductions in neural activity and negative blood oxygenation level-dependent (BOLD) signaling. However, the neural generators of the negative BOLD response remain to be characterized. Here, we use single-impulse electrical stimulation of the whisker pad in the anesthetized rat to identify components of the neural response that are related to “negative” hemodynamic changes in the brain. Laminar multiunit activity and local field potential recordings of neural activity were performed concurrently with two-dimensional optical imaging spectroscopy measuring hemodynamic changes. Repeated measurements over multiple stimulation trials revealed significant variations in neural responses across session and animal datasets. Within this variation, we found robust long-latency decreases (300 and 2000 ms after stimulus presentation) in gamma-band power (30–80 Hz) in the middle-superficial cortical layers in regions surrounding the activated whisker barrel cortex. This reduction in gamma frequency activity was associated with corresponding decreases in the hemodynamic responses that drive the negative BOLD signal. These findings suggest a close relationship between BOLD responses and neural events that operate over time scales that outlast the initiating sensory stimulus, and provide important insights into the neurophysiological basis of negative neuroimaging signals. PMID:25788681

  1. The Effects of a Multiflavonoid Supplement on Vascular and Hemodynamic Parameters following Acute Exercise

    PubMed Central

    Kappus, Rebecca M.; Curry, Chelsea D.; McAnulty, Steve; Welsh, Janice; Morris, David; Nieman, David C.; Soukup, Jeffrey; Collier, Scott R.

    2011-01-01

    Antioxidants can decrease oxidative stress and combined with acute exercise they may lead to further decreases in blood pressure. The purpose of this study was to investigate the effects of 2 weeks of antioxidant supplementation on vascular distensibility and cardiovascular hemodynamics during postexercise hypotension. Methods. Twenty young subjects were randomized to placebo (n = 10) or antioxidant supplementation (n = 10) for two weeks. Antioxidant status, vascular distensibility, and hemodynamics were obtained before, immediately, and 30 minutes after an acute bout of aerobic exercise both before and after supplementation. Results. Two weeks of antioxidant supplementation resulted in a greater systolic blood pressure (SBP) decrease during postexercise hypotension (PEH) and significant decreases in augmentation index versus placebo (12.5% versus 3.5%, resp.). Also ferric-reducing ability of plasma (FRAP) increased significantly (interaction P = 0.024) after supplementation. Conclusion. Supplementation showed an additive effect on PEH associated with increased FRAP values and decreases in systolic blood pressure and augmentation index. PMID:22191012

  2. Quantitative comparison of hemodynamic parameters from steady and transient CFD simulations in cerebral aneurysms with focus on the aneurysm ostium.

    PubMed

    Karmonik, C; Diaz, O; Klucznik, R; Grossman, R G; Zhang, Y J; Britz, G; Lv, N; Huang, Q

    2015-05-01

    To quantitatively compare hemodynamics simulated with steady-state and transient computational fluid dynamics (CFD) simulations in cerebral aneurysms with single inflow, with focus at the aneurysm ostium. Transient and steady-state CFD simulations were performed in 10 cerebral aneurysms. Distributions and average values for pressure, helicity, vorticity, and velocity were qualitatively compared at proximal and distal parent artery locations, at the ostium plane, and in the aneurysm, and scaling factors between the two kinds of simulations were determined. Relative inflow and outflow areas at the ostium were compared, as were average inflow and outflow velocities. In addition, values for the pressure-loss coefficient (PLC), a recently introduced parameter to assess aneurysm rupture risk, were compared for both kinds of simulation. Distributions of hemodynamic parameters had a similar shape but were lower for transient than for steady-state simulations. Averaged scaling factors over cases and anatomical locations showed differences for hemodynamic parameters (0.485 ± 0.01 for pressure, 0.33 ± 0.02 for helicity, 0.58 ± 0.06 for vorticity and 0.56 ± 0.04 for velocity). Good agreement between ratios of inflow and outflow areas at the aneurysm ostium was obtained (Pearson correlation coefficient >0.97, p<0.001) and for the PLC (linear regression slope 0.73 ± 0.14, R(2)=0.75). Steady-state simulations are a quick alternative to transient simulation for visualizing and quantifying inflow and outflow areas at the aneurysm ostium, potentially of value when planning flow diverter treatment and for quantifying the PLC, a potential indicator of aneurysm rupture. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  3. Hemodynamic changes in cortical sensorimotor systems following hand and orofacial motor tasks and pulsed pneumotactile stimulation.

    PubMed

    Rosner, Austin O; Barlow, Steven M

    We performed a functional near-infrared spectroscopy (fNIRS) study of the evoked hemodynamic responses seen in hand and face sensorimotor cortical representations during (1) active motor tasks and (2) pulsed pneumotactile stimulation. Contralateral fNIRS measurements were performed on 22 healthy adult participants using a block paradigm that consisted of repetitive right hand and right oral angle somatosensory stimulation using a pulsed pneumotactile array stimulator, and repetitive right-hand grip compression and bilabial compressions on strain gages. Results revealed significant oxyhemoglobin (HbO) modulation across stimulus conditions in corresponding somatotopic cortical regions. Of the 22 participants, 86% exhibited a decreased HbO response during at least one of the stimulus conditions, which may be indicative of cortical steal, or hypo-oxygenation occurring in channels adjacent to the primary areas of activation. Across all conditions, 56% of participants' HbO responses were positive and 44% were negative. Hemodynamic responses most likely differed across hand and face motor and somatosensory cortical regions due to differences in regional arterial/venous anatomy, cortical vascular beds, extent and orientation of somatotopy, task dynamics, and mechanoreceptor typing in hand and face. The combination of optical imaging and task conditions allowed for non-invasive examination of hemodynamic changes in somatosensory and motor cortices using natural, pneumatic stimulation of glabrous hand and hairy skin of the lower face and functionally relevant and measurable motor tasks involving the same structures.

  4. Hemodynamic Changes in Treated Cerebral Aneurysms and Correlations with Long-Term Outcomes

    NASA Astrophysics Data System (ADS)

    McGah, Patrick; Barbour, Michael; Levitt, Michael; Kim, Louis; Aliseda, Alberto

    2014-11-01

    The hemodynamic conditions in patients with cerebral aneurysms undergoing treatment, e.g. flow diverting stents or coil embolization, are investigated via computational simulations. Patient-specific 3D models of the vasculature are derived from rotational angiography. Patient-specific flow and pressure boundary conditions are prescribed utilizing intravascular pressure and velocity measurements. Pre-treatment and immediate post-treatment hemodynamics are studied in eight cases so as to ascertain the effect of the treatment on the intra-aneurysmal flow and wall shear stress. We hypothesize that larger reductions in intra-aneurysmal inflow and wall shear stress after treatment are correlated with an increased likelihood of aneurysmal occlusion and treatment success. Results indicate reductions of the intra-aneurysmal inflow and wall shear stress in all cases. Preliminary clinical six-month follow-up data, assessing if the treatment has been successful, shows that the cases with a persistent aneurysm had a smaller reduction in inflow and wall shear stress magnitude in the immediate post-treatment conditions. This suggests that CFD can be used to quantify a treatment's probability of success by computing the change in pre-and-post-treatment hemodynamics in cerebral aneurysms. NIH-NINDS.

  5. Comparison of hemodynamic, biochemical and hematological parameters of healthy pregnant women in the third trimester of pregnancy and the active labor phase

    PubMed Central

    2011-01-01

    Background Pregnancy is accompanied by several hemodynamic, biochemical and hematological changes which revert to normal values after labor. The mean values of these parameters have been reported for developed countries, but not for Mexican women. Furthermore, labor constitutes a stress situation, in which these factors may be altered. It is known that serologic increase of heat shock protein (Hsp) 70 is associated with abnormal pregnancies, presenting very low level in normal pregnant women. Nevertheless, there are no studies where these measurements are compared in healthy pregnant women at their third trimester of pregnancy (3TP) and the active labor phase (ActLP). Methods Seventy five healthy Mexican pregnant women were included. Hemodynamic, biochemical and hematological parameters were obtained in all cases, and serum Hsp70 levels were measured in a sample of 15 women at 3TP and at ActLP. Results Significant differences were found in most analysis performed and in Hsp70 concentration at 3TP as compared to ActLP, however all were within normal range in both conditions, supporting that only in pathological pregnancies Hsp70 is drastically increased. Conclusion Results obtained indicate that 3TP and ActLP have clinical similarities in normal pregnancies, therefore if abnormalities are found during 3TP, precautions should be taken before ActLP. PMID:21548965

  6. Comparison of hemodynamic, biochemical and hematological parameters of healthy pregnant women in the third trimester of pregnancy and the active labor phase.

    PubMed

    Rodríguez-Dennen, Fernando; Martínez-Ocaña, Joel; Kawa-Karasik, Simón; Villanueva-Egan, Luis; Reyes-Paredes, Norberto; Flisser, Ana; Olivo-Díaz, Angélica

    2011-05-06

    Pregnancy is accompanied by several hemodynamic, biochemical and hematological changes which revert to normal values after labor. The mean values of these parameters have been reported for developed countries, but not for Mexican women. Furthermore, labor constitutes a stress situation, in which these factors may be altered. It is known that serologic increase of heat shock protein (Hsp) 70 is associated with abnormal pregnancies, presenting very low level in normal pregnant women. Nevertheless, there are no studies where these measurements are compared in healthy pregnant women at their third trimester of pregnancy (3TP) and the active labor phase (ActLP). Seventy five healthy Mexican pregnant women were included. Hemodynamic, biochemical and hematological parameters were obtained in all cases, and serum Hsp70 levels were measured in a sample of 15 women at 3TP and at ActLP. Significant differences were found in most analysis performed and in Hsp70 concentration at 3TP as compared to ActLP, however all were within normal range in both conditions, supporting that only in pathological pregnancies Hsp70 is drastically increased. Results obtained indicate that 3TP and ActLP have clinical similarities in normal pregnancies, therefore if abnormalities are found during 3TP, precautions should be taken before ActLP.

  7. Changes in Hemodynamic Response Patterns in Motor Cortices Measured by Task-Based Functional Magnetic Resonance Imaging in Patients With Moyamoya Disease.

    PubMed

    Qiao, Peng-Gang; Zuo, Zhi-Wei; Han, Cong; Zhou, Juan; Zhang, Hong-Tao; Duan, Lian; Qian, Tianyi; Li, Gong-Jie

    We aimed to study the value of blood oxygen level-dependent functional magnetic resonance imaging (BOLD-fMRI) in assessing cerebral hemodynamic changes for moyamoya disease (MMD). We recruited 15 healthy volunteers, 15 patients with MMD without dyskinesia, and 30 patients with MMD who experienced paroxysmal limb dyskinesia. The BOLD-fMRI scans were obtained during grasping motions of the left or right hand. Hemodynamic response curves in the primary motor cortices were generated. Six response parameters including negative response time (Tnr), maximum signal intensity of negative response, time to peak, maximum peak arrival time, maximum signal intensity of positive response, and positive response time were measured. The hemodynamic response curve in the primary motor cortices of MMD patients showed extended Tnr, prolonged positive response time, and delayed time to peak than those of the controls. The response curve showed longer Tnr and maximum peak arrival time in the primary motor cortices on the affected side of the dyskinesia group. Blood oxygen level-dependent fMRI is an effective technique to assess hemodynamic changes in patients with MMD.

  8. Comparison of the pulsatility index and input impedance parameters in a model of altered hemodynamics.

    PubMed

    Downing, G J; Yarlagadda, A P; Maulik, D

    1991-06-01

    Clinical use of Doppler waveform analysis assumes that vascular resistance is accurately represented by the Doppler indices. This assumption was examined by correlating the pulsatility index (PI) with measures of input impedance including peripheral vascular resistance (Zpr), characteristic impedance (Zo), and reflection coefficient (Rc). Assessment of these parameters from the descending aorta was performed in five chronically instrumented, newborn lambs subjected to administration of norepinephrine and hydralazine. Significant increases in PI, Zpr, Zo, and Rc were seen in response to administration of norepinephrine, and decreases in PI and Zpr occurred with hydralazine use. Significant correlation existed between PI and Zpr throughout the study, but changes in PI did not correlate with changes in Zo and Rc. PI appears to reflect changes in Zpr accurately. However, the lack of ability for PI to assess Zo or Rc requires further investigation.

  9. PNU-282987 improves the hemodynamic parameters by alleviating vasopermeability and tissue edema in dogs subjected to a lethal burns shock.

    PubMed

    Hu, Quan; Du, Ming-Hua; Hu, Sen; Chai, Jia-ke; Luo, Hong-Min; Hu, Xiao-Han; Zhang, Lin; Lin, Zhi-Long; Ma, Li; Wang, Huan; Sheng, Zhi-Yong

    2014-01-01

    Excessive inflammation and high vasopermeability can lead to blood volume loss and tissue edema, which can affect the resuscitation and prognosis for serious burn patients. In this experiment, we investigated the effect of PNU-282987, an α7 nicotine cholinergic receptor agonist on the hemodynamic parameters and survival rate by inhibiting vasopermeability and tissue edema during the fluid resuscitation for lethal burn shock. Forty Beagle dogs with intubation of the carotid artery and jugular vein 24 hours before the injury were subjected to 50% TBSA full-thickness burns, and were randomly divided into following four groups: no resuscitation group (group NR), venous fluid resuscitation group (group R), PNU-282987 treatment group (group P), and fluid resuscitation group plus PNU-282987 group (group RP), with 10 dogs in each group. Hemodynamic variables and biochemical parameters were determined with animals in a conscious and cooperative state. The plasma volume and the vasopermeability were determined by indocyanine green and fluorescein isothiocyanate-dextran, respectively. The level of tumor necrosis factor-α and interleukin-1β in plasma, and the water content of different organs were also determined. The mean arterial pressure, cardiac output, and plasma volume of all dogs decreased significantly, and the lung extravascular water index and pulmonary vascular permeability index increased remarkably after burn. The hemodynamic parameters deteriorated continually in group N dogs, and then anuria, hyperlactacidemia, and multiple organ dysfunctions developed. The mean arterial pressure and cardiac output of dogs in group R and group RP returned to preinjury levels at 48 hours postburn. The lung extravascular water index and pulmonary vascular permeability in group R were higher than those before preinjury. The dogs in group RP were found to have a significant increase in plasma volume and urine output, and a remarkable decrease in the levels of tumor necrosis

  10. Pulmonary arterial hypertension in Saudi Arabia: Patients' clinical and physiological characteristics and hemodynamic parameters. A single center experience

    PubMed Central

    Idrees, MM; Al-Najashi, K; Khan, A; Al-Dammas, S; Al-Awwad, H; Batubara, E; Al Otai, A; Abdulhameed, J; Fayed, A; Kashour, T

    2014-01-01

    AIMS: The main objective of this study is to describe patients' clinical characteristics and physiological and hemodynamic parameters at the time of diagnosis in a pulmonary hypertension center in Saudi Arabia. MATERIALS AND METHODS: This study reports the results from a single pulmonary hypertension specialized center in Riyadh, Saudi Arabia, namely Prince Sultan Medical Military City/Cardiac Center (PSMMC & CC). Both newly diagnosed (incidence) and referred (prevalence) cases of pulmonary arterial hypertension are included. All characteristics, including clinical, physiological, and hemodynamic parameters at the time of diagnosis are described. RESULTS: A total of 107 patients were identified as having pulmonary arterial hypertension as diagnosed by right heart catheterization. The mean age at diagnosis was 36 (± 9) years, and there was a female preponderance of 62.6%. The mean duration between symptom onset and diagnosis was 27.8 (± 9.0) months. At the time of enrollment, 56.1% of patients were in functional class III and 16.8% were in functional class IV. Fifty five patients (51.4%) were diagnosed as idiopathic pulmonary arterial hypertension, 29 patients (27.1%) as congenital heart disease associated with pulmonary arterial hypertension, 16 patients (15.0%) as connective tissue diseases associated with pulmonary arterial hypertension, 4 patients (3.7%) as heritable pulmonary arterial hypertension, and 3 patients (2.8%) as portopulmonary hypertension. CONCLUSION: This data highlights the current situation of pulmonary arterial hypertension in Saudi Arabia. Our patients are much younger than patients described in other international registries but still detected as late in the course of the disease. A majority of patients displays severe functional and hemodynamic compromise. PMID:25276239

  11. Cognitive Difficulty Intensifies Age-related Changes in Anterior Frontal Hemodynamics: Novel Evidence from Near-infrared Spectroscopy.

    PubMed

    Bierre, Kirstin L; Lucas, Samuel J E; Guiney, Hayley; Cotter, James D; Machado, Liana

    2017-02-01

    Alongside age-related brain deterioration, cognitive functioning declines, particularly for more demanding tasks. Past research indicates that, to offset this decline, older adults exhibit hemodynamic changes consistent with recruitment of more anterior brain regions. However, the nature of the hemodynamic changes remains unclear. To address this knowledge gap, we used near-infrared spectroscopy in 36 young adults (aged 18-30 years) and 36 older adults (aged 60-72 years) to assess anterior frontal hemodynamic responses to engagement in three cognitive tasks of increasing difficulty. Behavioral results for all three tasks confirmed aging deficits (evidenced by slower reaction times and reduced accuracy rates) that progressively increased with task difficulty. Hemodynamic results showed opposing effects in young versus older adults, with oxygenated and total hemoglobin decreasing in young but increasing in older adults, particularly during the harder tasks. Also, tissue oxygenation increased only in older adults during the harder tasks. Among the older adults only, anterior frontal hemodynamic changes correlated with better cognitive performance, indicating that they were compensatory in nature. These findings provide novel evidence of age-related anterior frontal hemodynamic changes that intensify with cognitive demands and compensate for performance deficits.

  12. Imaging brain hemodynamic changes during rat forepaw electrical stimulation using functional photoacoustic microscopy.

    PubMed

    Liao, Lun-De; Li, Meng-Lin; Lai, Hsin-Yi; Shih, Yen-Yu I; Lo, Yu-Chun; Tsang, Siny; Chao, Paul Chang-Po; Lin, Chin-Teng; Jaw, Fu-Shan; Chen, You-Yin

    2010-08-15

    The present study reported the development of a novel functional photoacoustic microscopy (fPAM) system for investigating hemodynamic changes in rat cortical vessels associated with electrical forepaw stimulation. Imaging of blood optical absorption by fPAM at multiple appropriately-selected and distinct wavelengths can be used to probe changes in total hemoglobin concentration (HbT, i.e., cerebral blood volume [CBV]) and hemoglobin oxygen saturation (SO(2)). Changes in CBV were measured by images acquired at a wavelength of 570nm (lambda(570)), an isosbestic point of the molar extinction spectra of oxy- and deoxy-hemoglobin, whereas SO(2) changes were sensed by pixel-wise normalization of images acquired at lambda(560) or lambda(600) to those at lambda(570). We demonstrated the capacity of the fPAM system to image and quantify significant contralateral changes in both SO(2) and CBV driven by electrical forepaw stimulation. The fPAM system complements existing imaging techniques, with the potential to serve as a favorable tool for explicitly studying brain hemodynamics in animal models.

  13. Central hemodynamic changes of calcium antagonists at rest and during exercise in essential hypertension.

    PubMed

    Lund-Johansen, P; Omvik, P

    1987-01-01

    Since the cardinal hemodynamic disorder in essential hypertension is an increased total peripheral resistance, drugs that can lower resistance without reducing blood flow would be particularly useful. The calcium antagonists seem to fulfill this criterion. The purpose of this work was to study the hemodynamic effects at rest and during exercise of three calcium channel blockers, verapamil, nifedipine, and nisoldipine, in patients with mild to moderate essential hypertension. Fifty-four patients aged 20-64 years with pretreatment diastolic blood pressures of between 95 and 120 mm Hg were studied at rest and during exercise on an ergometer bicycle. Blood pressure was recorded intraarterially and cardiac output was measured by Cardiogreen. After the initial study, 10 patients were treated with verapamil (40-80 mg three times daily), 15 with nifedipine (long-acting form, 20-80 mg daily), and 19 with nisoldipine (10-40 mg daily). After 1 year the hemodynamic study was repeated. The immediate response to the first dose was studied in the patients taking nisoldipine and in 10 patients after taking placebo tablets. Placebo induced no significant changes in central hemodynamics during the first 3 h after tablet intake. The calcium antagonists induced a reduction in blood pressure and in total peripheral resistance (in the order of 10-18%) without any reduction in cardiac index. Reflex tachycardia and an increase in cardiac output were seen in the first 2 h after the first dose of nisoldipine, but after 1 year the heart rate was unchanged compared with the pretreatment rate at rest and during exercise. In contrast, heart rate was reduced on verapamil treatment, particularly during exercise (about 10% of patients), but this was compensated for by an increase in the stroke volume. The hemodynamic profiles of the three calcium channel blockers were slightly different, especially with respect to the heart rate response. Total peripheral resistance was reduced, acutely as well as

  14. Computer simulation of Cerebral Arteriovenous Malformation-validation analysis of hemodynamics parameters.

    PubMed

    Kumar, Y Kiran; Mehta, Shashi Bhushan; Ramachandra, Manjunath

    2017-01-01

    The purpose of this work is to provide some validation methods for evaluating the hemodynamic assessment of Cerebral Arteriovenous Malformation (CAVM). This article emphasizes the importance of validating noninvasive measurements for CAVM patients, which are designed using lumped models for complex vessel structure. The validation of the hemodynamics assessment is based on invasive clinical measurements and cross-validation techniques with the Philips proprietary validated software's Qflow and 2D Perfursion. The modeling results are validated for 30 CAVM patients for 150 vessel locations. Mean flow, diameter, and pressure were compared between modeling results and with clinical/cross validation measurements, using an independent two-tailed Student t test. Exponential regression analysis was used to assess the relationship between blood flow, vessel diameter, and pressure between them. Univariate analysis is used to assess the relationship between vessel diameter, vessel cross-sectional area, AVM volume, AVM pressure, and AVM flow results were performed with linear or exponential regression. Modeling results were compared with clinical measurements from vessel locations of cerebral regions. Also, the model is cross validated with Philips proprietary validated software's Qflow and 2D Perfursion. Our results shows that modeling results and clinical results are nearly matching with a small deviation. In this article, we have validated our modeling results with clinical measurements. The new approach for cross-validation is proposed by demonstrating the accuracy of our results with a validated product in a clinical environment.

  15. Computer simulation of Cerebral Arteriovenous Malformation—validation analysis of hemodynamics parameters

    PubMed Central

    Mehta, Shashi Bhushan; Ramachandra, Manjunath

    2017-01-01

    Problem The purpose of this work is to provide some validation methods for evaluating the hemodynamic assessment of Cerebral Arteriovenous Malformation (CAVM). This article emphasizes the importance of validating noninvasive measurements for CAVM patients, which are designed using lumped models for complex vessel structure. Methods The validation of the hemodynamics assessment is based on invasive clinical measurements and cross-validation techniques with the Philips proprietary validated software’s Qflow and 2D Perfursion. Results The modeling results are validated for 30 CAVM patients for 150 vessel locations. Mean flow, diameter, and pressure were compared between modeling results and with clinical/cross validation measurements, using an independent two-tailed Student t test. Exponential regression analysis was used to assess the relationship between blood flow, vessel diameter, and pressure between them. Univariate analysis is used to assess the relationship between vessel diameter, vessel cross-sectional area, AVM volume, AVM pressure, and AVM flow results were performed with linear or exponential regression. Discussion Modeling results were compared with clinical measurements from vessel locations of cerebral regions. Also, the model is cross validated with Philips proprietary validated software’s Qflow and 2D Perfursion. Our results shows that modeling results and clinical results are nearly matching with a small deviation. Conclusion In this article, we have validated our modeling results with clinical measurements. The new approach for cross-validation is proposed by demonstrating the accuracy of our results with a validated product in a clinical environment. PMID:28149675

  16. Variability of hemodynamic parameters using the common viscosity assumption in a computational fluid dynamics analysis of intracranial aneurysms.

    PubMed

    Suzuki, Takashi; Takao, Hiroyuki; Suzuki, Takamasa; Suzuki, Tomoaki; Masuda, Shunsuke; Dahmani, Chihebeddine; Watanabe, Mitsuyoshi; Mamori, Hiroya; Ishibashi, Toshihiro; Yamamoto, Hideki; Yamamoto, Makoto; Murayama, Yuichi

    2017-01-01

    In most simulations of intracranial aneurysm hemodynamics, blood is assumed to be a Newtonian fluid. However, it is a non-Newtonian fluid, and its viscosity profile differs among individuals. Therefore, the common viscosity assumption may not be valid for all patients. This study aims to test the suitability of the common viscosity assumption. Blood viscosity datasets were obtained from two healthy volunteers. Three simulations were performed for three different-sized aneurysms, two using measured value-based non-Newtonian models and one using a Newtonian model. The parameters proposed to predict an aneurysmal rupture obtained using the non-Newtonian models were compared with those obtained using the Newtonian model. The largest difference (25%) in the normalized wall shear stress (NWSS) was observed in the smallest aneurysm. Comparing the difference ratio to the NWSS with the Newtonian model between the two Non-Newtonian models, the difference of the ratio was 17.3%. Irrespective of the aneurysmal size, computational fluid dynamics simulations with either the common Newtonian or non-Newtonian viscosity assumption could lead to values different from those of the patient-specific viscosity model for hemodynamic parameters such as NWSS.

  17. Impact of manual lymphatic drainage on hemodynamic parameters in patients with heart failure and lower limb edema.

    PubMed

    Leduc, O; Crasset, V; Leleu, C; Baptiste, N; Koziel, A; Delahaie, C; Pastouret, F; Wilputte, F; Leduc, A

    2011-03-01

    Manual lymphatic drainage (MLD), intermittent sequential pneumatic therapy (ISPT), multilayered bandages (MLB), and compression garments are main techniques in conservative treatment of peripheral lymphedema. Since 1990, it has been thought that ISPT applied to both lower limbs simultaneously should not be used for patients with heart failure because right atrial, pulmonary arterial, and pulmonary wedge pressures may increase to a critical point. In 2005, these same results were observed in patients with heart failure wearing MLB. For these reasons, MLB and ISPT have been contraindicated during lymphedema treatment in cardiac patients. The aim of this study was to determine if we may continue the treatment of lower limb lymphedema using MLD in patients with heart failure. We evaluated hemodynamic parameters using echography during MLD in patients with cardiac disease and obtained circumferential measurements of the edematous limb before and after treatment. MLD treatment significantly decreased the limbs as expected. The heart rate also decreased following MLD in contrast with all other hemodynamic parameters which were not affected by MLD. The findings suggest that there is no contraindication to use MLD in patients with heart failure and lower limb edema.

  18. CMOS Image Sensor and System for Imaging Hemodynamic Changes in Response to Deep Brain Stimulation.

    PubMed

    Zhang, Xiao; Noor, Muhammad S; McCracken, Clinton B; Kiss, Zelma H T; Yadid-Pecht, Orly; Murari, Kartikeya

    2016-06-01

    Deep brain stimulation (DBS) is a therapeutic intervention used for a variety of neurological and psychiatric disorders, but its mechanism of action is not well understood. It is known that DBS modulates neural activity which changes metabolic demands and thus the cerebral circulation state. However, it is unclear whether there are correlations between electrophysiological, hemodynamic and behavioral changes and whether they have any implications for clinical benefits. In order to investigate these questions, we present a miniaturized system for spectroscopic imaging of brain hemodynamics. The system consists of a 144 ×144, [Formula: see text] pixel pitch, high-sensitivity, analog-output CMOS imager fabricated in a standard 0.35 μm CMOS process, along with a miniaturized imaging system comprising illumination, focusing, analog-to-digital conversion and μSD card based data storage. This enables stand alone operation without a computer, nor electrical or fiberoptic tethers. To achieve high sensitivity, the pixel uses a capacitive transimpedance amplifier (CTIA). The nMOS transistors are in the pixel while pMOS transistors are column-parallel, resulting in a fill factor (FF) of 26%. Running at 60 fps and exposed to 470 nm light, the CMOS imager has a minimum detectable intensity of 2.3 nW/cm(2) , a maximum signal-to-noise ratio (SNR) of 49 dB at 2.45 μW/cm(2) leading to a dynamic range (DR) of 61 dB while consuming 167 μA from a 3.3 V supply. In anesthetized rats, the system was able to detect temporal, spatial and spectral hemodynamic changes in response to DBS.

  19. Imaging hemodynamic changes in preterm infant brains with two-dimensional diffuse optical tomography

    NASA Astrophysics Data System (ADS)

    Gao, Feng; Ma, Yiwen; Yang, Fang; Zhao, Huijuan; Jiang, Jingying; Kusaka, Takashi; Ueno, Masanori; Yamada, Yukio

    2008-02-01

    We present our preliminary results on two-dimensional (2-D) optical tomographic imaging of hemodynamic changes of two preterm infant brains in different ventilation settings conditions. The investigations use the established two-wavelength, 16-channel time-correlated single photon counting system for the detection, and the generalized pulse spectrum technique based algorithm for the image reconstruction. The experiments demonstrate that two-dimensional diffuse optical tomography may be a potent and relatively simple way of investigating the functions and neural development of infant brains in the perinatal period.

  20. Paradoxical gas embolism after SCUBA diving: hemodynamic changes studied by echocardiography.

    PubMed

    Boussuges, A; Pontier, J M; Schmid, B; Dussault, C

    2014-02-01

    Hemodynamic changes induced by self-contained underwater breathing apparatus diving were investigated using Doppler echocardiography. We detected circulating bubbles in both right and left cavities of the heart and in the cerebral circulation in two divers with a large patent foramen ovale. A reduction in the left ventricular preload was suggested by echocardiographic measurements. The decreased cardiac preload was paralleled to a lower stroke volume and cardiac output. These findings were also observed in divers with no evidence of circulating bubbles. In these subjects, pulmonary vascular resistances remained unchanged while an increase was observed in the two divers with arterial bubbles. This increase could promote right-to-left shunting.

  1. Comparison of hemodynamic and nutritional parameters between older persons practicing regular physical activity, nonsmokers and ex-smokers

    PubMed Central

    2010-01-01

    Background Sedentary lifestyle combined with smoking, contributes to the development of a set of chronic diseases and to accelerating the course of aging. The aim of the study was to compare the hemodynamic and nutritional parameters between elderly persons practicing regular physical activity, nonsmokers and ex-smokers. Methods The sample was comprised of 40 elderly people practicing regular physical activity for 12 months, divided into a Nonsmoker Group and an Ex-smoker Group. During a year four trimestrial evaluations were performed, in which the hemodynamic (blood pressure, heart rate- HR and VO2) and nutritional status (measured by body mass index) data were collected. The paired t-test and t-test for independent samples were applied in the intragroup and intergroup analysis, respectively. Results The mean age of the groups was 68.35 years, with the majority of individuals in the Nonsmoker Group being women (n = 15) and the Ex-smoker Group composed of men (n = 11). In both groups the variables studied were within the limits of normality for the age. HR was diminished in the Nonsmoker Group in comparison with the Ex-smoker Group (p = 0.045) between the first and last evaluation. In the intragroup analysis it was verified that after one year of exercise, there was significant reduction in the HR in the Nonsmoker Group (p = 0.002) and a significant increase in VO2 for the Ex-smoker Group (p = 0.010). There are no significant differences between the hemodynamic and nutritional conditions in both groups. Conclusion In elderly persons practicing regular physical activity, it was observed that the studied variables were maintained over the course of a year, and there was no association with the history of smoking, except for HR and VO2. PMID:21040562

  2. Heart rate dependent and independent effects of beta-blockers on central hemodynamic parameters: a propensity score analysis.

    PubMed

    Goupil, Rémi; Dupuis, Dominique; Troyanov, Stéphan; Madore, François; Agharazii, Mohsen

    2016-08-01

    Central hemodynamic parameters are better predictors of the cardiovascular burden than peripheral blood pressure (BP). Beta-blockers are known to reduce central BP to a lesser extent than peripheral BP, a hypothesized mechanistic consequence of heart rate (HR) reduction. The association between beta-blocker use, HR and central hemodynamics indices was studied in treated hypertensive participants of the CARTaGENE study using propensity score analyses and multivariate linear regressions. Of the 20 004 participants, 2575 were treated hypertensive patients with valid pulse wave analysis. Using propensity score analyses, beta-blocker users (n = 605) were matched to nonusers having similar clinical characteristics with (Model 1) and without (Model 2) adjustment for HR. This resulted in 457 and 510 pairs with adequate balance, except for a HR difference in Model 2 (62.5 ± 10.5 vs. 70.4 ± 11.5 bpm, p < 0.001). In Model 1, the central pulse pressure (PP) was 46.5 ± 12.9 mmHg with beta-blocker compared with 45.4 ± 11.0 mmHg without (p = 0.045). PP amplification, augmentation index and augmented pressure were also less favorable with the use of beta-blocker. The HR difference in Model 2 further increased the difference in central PP observed with beta-blocker to 46.5 ± 13.0 vs. 43.3 ± 11.3 without (p < 0.001). These findings were similar when atenolol, metoprolol and bisoprolol were assessed separately using multivariate linear regression models. This study shows that the unfavorable central hemodynamic profile of beta-blocker has both HR-dependent and HR-independent components that are similar for all frequently used β1-selective beta-blocker.

  3. Changes in Cerebral Hemodynamics during Complex Motor Learning by Character Entry into Touch-Screen Terminals.

    PubMed

    Sagari, Akira; Iso, Naoki; Moriuchi, Takefumi; Ogahara, Kakuya; Kitajima, Eiji; Tanaka, Koji; Tabira, Takayuki; Higashi, Toshio

    2015-01-01

    Studies of cerebral hemodynamics during motor learning have mostly focused on neurorehabilitation interventions and their effectiveness. However, only a few imaging studies of motor learning and the underlying complex cognitive processes have been performed. We measured cerebral hemodynamics using near-infrared spectroscopy (NIRS) in relation to acquisition patterns of motor skills in healthy subjects using character entry into a touch-screen terminal. Twenty healthy, right-handed subjects who had no previous experience with character entry using a touch-screen terminal participated in this study. They were asked to enter the characters of a randomly formed Japanese syllabary into the touch-screen terminal. All subjects performed the task with their right thumb for 15 s alternating with 25 s of rest for 30 repetitions. Performance was calculated by subtracting the number of incorrect answers from the number of correct answers, and gains in motor skills were evaluated according to the changes in performance across cycles. Behavioral and oxygenated hemoglobin concentration changes across task cycles were analyzed using Spearman's rank correlations. Performance correlated positively with task cycle, thus confirming motor learning. Hemodynamic activation over the left sensorimotor cortex (SMC) showed a positive correlation with task cycle, whereas activations over the right prefrontal cortex (PFC) and supplementary motor area (SMA) showed negative correlations. We suggest that increases in finger momentum with motor learning are reflected in the activity of the left SMC. We further speculate that the right PFC and SMA were activated during the early phases of motor learning, and that this activity was attenuated with learning progress.

  4. Changes in Cerebral Hemodynamics during Complex Motor Learning by Character Entry into Touch-Screen Terminals

    PubMed Central

    Sagari, Akira; Iso, Naoki; Moriuchi, Takefumi; Ogahara, Kakuya; Kitajima, Eiji; Tanaka, Koji; Tabira, Takayuki; Higashi, Toshio

    2015-01-01

    Introduction Studies of cerebral hemodynamics during motor learning have mostly focused on neurorehabilitation interventions and their effectiveness. However, only a few imaging studies of motor learning and the underlying complex cognitive processes have been performed. Methods We measured cerebral hemodynamics using near-infrared spectroscopy (NIRS) in relation to acquisition patterns of motor skills in healthy subjects using character entry into a touch-screen terminal. Twenty healthy, right-handed subjects who had no previous experience with character entry using a touch-screen terminal participated in this study. They were asked to enter the characters of a randomly formed Japanese syllabary into the touch-screen terminal. All subjects performed the task with their right thumb for 15 s alternating with 25 s of rest for 30 repetitions. Performance was calculated by subtracting the number of incorrect answers from the number of correct answers, and gains in motor skills were evaluated according to the changes in performance across cycles. Behavioral and oxygenated hemoglobin concentration changes across task cycles were analyzed using Spearman’s rank correlations. Results Performance correlated positively with task cycle, thus confirming motor learning. Hemodynamic activation over the left sensorimotor cortex (SMC) showed a positive correlation with task cycle, whereas activations over the right prefrontal cortex (PFC) and supplementary motor area (SMA) showed negative correlations. Conclusions We suggest that increases in finger momentum with motor learning are reflected in the activity of the left SMC. We further speculate that the right PFC and SMA were activated during the early phases of motor learning, and that this activity was attenuated with learning progress. PMID:26485534

  5. [The adrenergic mechanisms are involved in the pulmonary hemodynamics changes following experimental myocardial ischemia in rabbits].

    PubMed

    Evlakhov, V I; Poiasov, I Z

    2012-05-01

    In acute experiments in anesthetized rabbits the changes of the pulmonary hemodynamics following myocardial ischemia in the region of the descendent left coronary artery were studied in control animals and after the blockade of alpha-adrenoreceptors by phentolamine or N-cholinoreceptors of autonomic ganglia by hexamethonium. Following myocardial ischemia in control animals the pulmonary artery pressure and flow decreased, the pulmonary vascular resistance was elevated not significantly, the cardiac output decreased more than pulmonary artery flow. Following myocardial ischemia after the blockade of alpha-adrenoreceptors the pulmonary artery flow and cardiac output decreased in the same level and the pulmonary vascular resistance was decreased. In these conditions the pulmonary artery pressure decreased more than in control animals, meanwhile the pulmonary artery flow was decreased in the same level as in the last case. Following myocardial ischemia after the blockade of N-cholinoreceptors the pulmonary hemodynamics changes were the same as they were following myocardial ischemia in the control rabbits, the cardiac output decreased more than pulmonary artery flow. The disbalance of the cardiac output and pulmonary artery flow changes in the case of myocardial ischemia was caused by the pulmonary vessel reactions following activations of the humoral adrenergic mechanisms.

  6. Comparison of neostigmine and sugammadex for hemodynamic parameters in cardiac patients undergoing noncardiac surgery.

    PubMed

    Kizilay, Deniz; Dal, Didem; Saracoglu, Kemal T; Eti, Zeynep; Gogus, Fevzi Y

    2016-02-01

    The aim of this study is to compare the hemodynamic effects of neostigmine-atropine combination and sugammadex in patients with cardiac problems undergoing noncardiac surgery. Prospective randomized study. In the operating room. Ninety patients with a class 2 or 3 cardiovascular disease according to the New York Heart Association classification and aged between 18 and 75 years undergoing noncardiac surgery were randomized. Group N (n = 45) received 0.03 mg/kg IV neostigmine when T2 appeared as measured with a nerve muscle stimulator. When heart rate was 5 beats/min (±10 beats/min) lower than the heart rate before administration of the medication, 0.5 mg IV atropine sulfate was given. Group S (n = 45) received 3 mg/kg IV sugammadex when T2 appeared as measured with a nerve muscle stimulator. Heart rate, mean systolic and diastolic blood pressures, and electrocardiographic alterations including the QTc (QT Fredericia and QT Bazett) were recorded. There were no significant differences between and within the groups in terms of QTc values. Sugammadex group had a significant decrease on heart rate 1 minute after the medication when compared to the measurement before the medication (P < .05). Heart rate and systolic blood pressure increased in neostigmine group 3 minutes after the medication and during postoperative measurements (P < .05). Sugammadex group had lower systolic, diastolic, and mean blood pressures and heart rate when compared to neostigmine group (P < .05). We suggest that sugammadex might be preferred as it provides more hemodynamic stability compared to neostigmine-atropine combination to reverse rocuronium-induced neuromuscular blockage in cardiac patients undergoing noncardiac surgery. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. A Coupled Lumped-Parameter and Distributed Network Model for Cerebral Pulse-Wave Hemodynamics

    PubMed Central

    Ryu, Jaiyoung; Hu, Xiao; Shadden, Shawn C.

    2015-01-01

    The cerebral circulation is unique in its ability to maintain blood flow to the brain under widely varying physiologic conditions. Incorporating this autoregulatory response is necessary for cerebral blood flow (CBF) modeling, as well as investigations into pathological conditions. We discuss a one-dimensional (1D) nonlinear model of blood flow in the cerebral arteries coupled to autoregulatory lumped-parameter (LP) networks. The LP networks incorporate intracranial pressure (ICP), cerebrospinal fluid (CSF), and cortical collateral blood flow models. The overall model is used to evaluate changes in CBF due to occlusions in the middle cerebral artery (MCA) and common carotid artery (CCA). Velocity waveforms at the CCA and internal carotid artery (ICA) were examined prior and post MCA occlusion. Evident waveform changes due to the occlusion were observed, providing insight into cerebral vasospasm monitoring by morphological changes of the velocity or pressure waveforms. The role of modeling of collateral blood flows through cortical pathways and communicating arteries was also studied. When the MCA was occluded, the cortical collateral flow had an important compensatory role, whereas the communicating arteries in the circle of Willis (CoW) became more important when the CCA was occluded. To validate the model, simulations were conducted to reproduce a clinical test to assess dynamic autoregulatory function, and results demonstrated agreement with published measurements. PMID:26287937

  8. Invasive hemodynamics of constrictive pericarditis.

    PubMed

    Doshi, Shrenik; Ramakrishnan, Sivasubramanian; Gupta, Saurabh Kumar

    2015-01-01

    Cardiac catheterization and hemodynamic study is the gold standard for the diagnosis of pericardial constriction. Careful interpretation of the hemodynamic data is essential to differentiate it from other diseases with restrictive physiology. In this hemodynamic review we shall briefly discuss the physiologic basis of various hemodynamic changes seen in a patient with constrictive pericarditis.

  9. Endotoxin-induced hemodynamic changes in dogs: role of thromboxane and prostaglandin I2.

    PubMed

    Bottoms, G D; Johnson, M A; Roesel, O F

    1983-08-01

    Plasma concentrations of thromboxane and prostaglandin I2 (PGI2) before and after IV injection of endotoxin and resulting hemodynamic changes were evaluated. Effects of flunixin meglumine on plasma concentrations of these prostaglandins and the related hemodynamic changes were also determined. Shock was induced in 2 groups of anesthetized dogs. Four dogs were given endotoxin only and 4 dogs were given endotoxin and then were treated with flunixin meglumine. Arterial blood pressure (BP), cardiac output (CO), and heart rate were measured, and blood samples were collected at postendotoxin hours (PEH) 0, 0.1, 0.25, 0.5, 1, 2, 3, and 4. Plasma thromboxane and PGI2 concentrations were increased in canine endotoxic shock. Thromboxane concentration was highest early in shock, and appeared to be associated with an initial decrease in BP and CO. The increased concentration of PGI2 was associated with systemic hypotension at PEH 1 to 2. Treatment of dogs with flunixin meglumine at PEH 0.07 prevented further increase of thromboxane and blocked the release of PGI2, resulting in an increased CO, BP, and tissue aerobic metabolism.

  10. Transcranial imaging of functional cerebral hemodynamic changes in single blood vessels using in vivo photoacoustic microscopy

    PubMed Central

    Liao, Lun-De; Lin, Chin-Teng; Shih, Yen-Yu I; Duong, Timothy Q; Lai, Hsin-Yi; Wang, Po-Hsun; Wu, Robby; Tsang, Siny; Chang, Jyh-Yeong; Li, Meng-Lin; Chen, You-Yin

    2012-01-01

    Optical imaging of changes in total hemoglobin concentration (HbT), cerebral blood volume (CBV), and hemoglobin oxygen saturation (SO2) provides a means to investigate brain hemodynamic regulation. However, high-resolution transcranial imaging remains challenging. In this study, we applied a novel functional photoacoustic microscopy technique to probe the responses of single cortical vessels to left forepaw electrical stimulation in mice with intact skulls. Functional changes in HbT, CBV, and SO2 in the superior sagittal sinus and different-sized arterioles from the anterior cerebral artery system were bilaterally imaged with unambiguous 36 × 65-μm2 spatial resolution. In addition, an early decrease of SO2 in single blood vessels during activation (i.e., ‘the initial dip') was observed. Our results indicate that the initial dip occurred specifically in small arterioles of activated regions but not in large veins. This technique complements other existing imaging approaches for the investigation of the hemodynamic responses in single cerebral blood vessels. PMID:22472612

  11. Measurement of hemodynamic changes with the axial flow blood pump installed in descending aorta.

    PubMed

    Okamoto, Eiji; Yano, Tetsuya; Miura, Hidekazu; Shiraishi, Yasuyuki; Yambe, Tomoyuki; Mitamura, Yoshinori

    2017-09-08

    We have developed various axial flow blood pumps to realize the concept of the Valvo pump, and we have studied hemodynamic changes under cardiac assistance using an axial flow blood pump in series with the natural heart. In this study, we measured hemodynamic changes of not only systemic circulation but also cerebral circulation and coronary circulation under cardiac support using our latest axial flow blood pump placed in the descending aorta in an acute animal experiment. The axial flow blood pump was installed at the thoracic descending aorta through a left thoracotomy of a goat (43.8 kg, female). When the pump was on, the aortic pressure and aortic flow downstream of the pump increased with preservation of pulsatilities. The pressure drop upstream of the pump caused reduction of afterload pressure, and it may lead to reduction of left ventricular wall stress. However, cerebral blood flow and coronary blood flow were decreased when the pump was on. The axial flow blood pump enables more effective blood perfusion into systemic circulation, but it has the potential risk of blood perfusion disturbance into cerebral circulation and coronary circulation. The results indicate that the position before the coronary ostia might be suitable for implantation of the axial flow blood pump in series with the natural heart to avoid blood perfusion disturbances.

  12. Comparison of changes in hemodynamics between unilateral and bilateral lung volume reduction for pulmonary emphysema.

    PubMed

    Koizumi, K; Haraguchi, S; Akiyama, H; Hirata, T; Hirai, K; Mikami, I; Tanaka, S

    2001-10-01

    This study was aimed to compare changes in hemodynamics between unilateral (UL) or simultaneous bilateral (BL) lung volume reduction surgery (LVRS) for chronic obstructive lung disease. Sixteen patients underwent LVRS by stapler resection with neodymium: yttrium-alminum-garnet (Nd: YAG) laser ablation; five underwent BL-LVRS (four by median sternotomy and one by thoracoscopy) and 11 underwent UL-LVRS by thoracoscopy. Four patients had multiple bullae within pulmonary emphysema. At preoperation and 6, 12, 24, and 48 hours postoperatively, hemodynamics and right ventricular performance were evaluated. UL- and BL-LVRS reduced afterload of the right and left ventricle postoperatively. Although the pulmonary arterial resistance increased after surgery, the total pulmonary resistance decreased (p=0.001) in association with the reduced systemic vascular resistance (p=0.001). These reductions improved cardiopulmonary circulation, resulting in increased stroke volume and cardiac output (p=0.003). The right ventricular ejection fraction showed minimal change 48 hours postoperation. Two patients died of pneumonia caused by persistent air leakage. In conclusion, both the UL- and BL-LVRS showed similar effectiveness in terms of improvement in the systemic and cardiopulmonary circulation after LVRS, if there were no postoperative complications. We concluded that we had to reduce and repair the persistent air leakage after LVRS.

  13. Cerebral watershed infarcts may be induced by hemodynamic changes in blood flow.

    PubMed

    Shi, Jingfei; Meng, Ran; Konakondla, Sanjay; Ding, Yuchuan; Duan, Yunxia; Wu, Di; Wang, Bincheng; Luo, Yinghao; Ji, Xunming

    2017-06-01

    A watershed infarct is defined as an ischemic lesion at the border zones between territories of two major arteries. The pathogenesis of watershed infarcts, specifically whether they are caused by hemodynamic or embolic mechanisms, has long been debated. In this study, we aimed to examine whether watershed infarcts can be induced by altering the hemodynamic conditions in rats. In phase one, to determine the proper clamping duration for a reproducible infarct, 30 rats were equally divided into 5 subgroups and underwent bilateral common carotid artery (CCA) clamping for different durations (0.5, 1.0, 1.5, 2.0, and 3.0 hours). In phase two, to analyze the types of infarcts induced by bilateral CCA clamping, 40 rats were subjected to bilateral CCA clamping for 2 hours. As a control, 8 rats underwent all the operation procedures except bilateral CCA clamping. We performed 7.0T magnetic resonance imaging on the surviving rats on the second day to evaluate the extent of the infarcts. We further identified and examined the infarcts with brain slices stained using 2, 3, 5-triphenyltetrazolium chloride (TTC) on the third day. After 2 hours of bilateral CCA clamping, cerebral infarction occurred in 42% of surviving rats (13/31). The majority of the ischemic lesions were located in watershed regions of the brain, demonstrated by both MRI and TTC staining. Watershed infarcts were induced through changing hemodynamic conditions by bilateral CCA clamping in rats. This method may lead to the development of a reliable rodent model for watershed infarcts.

  14. Normal Pregnancy Is Associated with Changes in Central Hemodynamics and Enhanced Recruitable, but Not Resting, Endothelial Function

    PubMed Central

    Zócalo, Yanina; Farro, Ignacio; Farro, Federico; Scasso, Santiago; Bia, Daniel

    2015-01-01

    Introduction. Flow-mediated dilation (FMD), low flow-mediated constriction (L-FMC), and reactive hyperemia-related changes in carotid-to-radial pulse wave velocity (ΔPWVcr%) could offer complementary information about both “recruitability” and “resting” endothelial function (EF). Carotid-to-femoral pulse wave velocity (PWVcf) and pulse wave analysis-derived parameters (i.e., AIx@75) are the gold standard methods for noninvasive evaluation of aortic stiffness and central hemodynamics. If healthy pregnancy is associated with both changes in resting and recruitable EF, as well as in several arterial parameters, it remains unknown and/or controversial. Objectives. To simultaneously and noninvasively assess in healthy pregnant (HP) and nonpregnant (NP) women central parameters in conjunction with “basal and recruitable” EF, employing new complementary approaches. Methods. HP (n = 11, 34.2 ± 3.3 weeks of gestation) and age- and cardiovascular risk factors-matched NP (n = 22) were included. Aortic blood pressure (BP), AIx@75, PWVcf, common carotid stiffness, and intima-media thickness, as well as FMD, L-FMC, and ΔPWVcr %, were measured. Results. Aortic BP, stiffness, and AIx@75 were reduced in HP. ΔPWVcr% and FMD were enhanced in HP in comparison to NP. No differences were found in L-FMC between groups. Conclusion. HP is associated with reduced aortic stiffness, central BP, wave reflections, and enhanced recruitable, but not resting, EF. PMID:26421317

  15. The correlation between anthropometric indices and hemodynamic changes after laryngoscopy and endotracheal intubation.

    PubMed

    Safavi, Mohammadreza; Honarmand, Azim; Dasgerdi, Elham Ghorbani; Sharifi, Ghasem Mohammad

    2016-01-01

    Cardiovascular hemodynamic changes after laryngoscopy and endotracheal intubations can cause serious complications. This study was carried out to evaluate the correlation between the anthropometric indices and hemodynamic changes after laryngoscopy and endotracheal intubation (EI). This descriptive-analytical pilot study was carried out in 2012, in the Kashani Hospital, Isfahan, Iran. After obtaining written informed consent from 130 patients who fulfilled the inclusion criteria, they were enrolled in the study. The recorded data included were, age, weight, height, neck circumference (NC), waist-to-hip ratio (W/H ratio) and body mass index (BMI). The heart rate (HR), systolic blood pressure (SAP), diastolic blood pressure (DBP), and mean arterial blood pressure (MAP) were recorded at baseline (before injection of the anesthetic drugs), just before laryngoscopy, and one, three, five, and ten minutes after EI. The best cut-off points for BMI, NC, and W/H ratio, for prediction of significant cardiovascular changes after EI were, 26.56 kg/m(2), 38 cm, and 0.82, respectively. There was a significant correlation between BMI and HR changes in the first and fifth minutes and also in MAP in the third and fifth minutes after EI (P < 0.05). Moreover, there was a significant correlation between NC and MAP in the fifth minute (P < 0.05). The W/H ratio was significantly related to the DBP in the tenth minute and MAP in the fifth and tenth minutes (P < 0.05). Based on the results of this study, among the anthropometric indices, the BMI, NC, and W/H ratio were significantly correlated with cardiovascular changes after laryngoscopy and tracheal intubation.

  16. Strange hemodynamic attractor parameter with 1/R total artificial heart automatic control algorithm.

    PubMed

    Yambe, T; Abe, Y; Yoshizawa, M; Imachi, K; Tabayashi, K; Takayasu, H; Takeda, H; Gouhara, K; Nitta, S

    1996-05-01

    To evaluate the automatic control algorithm of the total artificial heart (TAH) as an entity, and not just as parts, a non-linear mathematical analyzing technique including chaos theory was utilized. Chronic experiments on the biventricular bypass type artificial heart implantation were performed in healthy adult goats after the natural ventricles were removed. Hemodynamic time series data were recorded under the awake standing condition with TAH 1/R and fixed driving. Time series data were recorded on a magnetic tape and analyzed on a personal computer system with an A-D converter. Using the nonlinear mathematical technique, the time series data were embedded into the phase space and the Lyapunov numerical method was carried out for the quantitative evaluation of the sensitive dependence on the initial condition of the reconstructed attractor. Calculation of the largest Lyapunov exponents suggested that the reconstructed attractor of the left pump output during TAH 1/R control was a larger dimensional strange attractor, a characteristic pattern of deterministic chaos. A total system indicating chaotic dynamics was thought to be a flexible and intelligent control system. Thus, our results suggest that 1/R TAH control may be suitable for the biventricular assist type total artificial heart.

  17. A hemodynamic-based dimensionless parameter for predicting rupture of intracranial aneurysms

    NASA Astrophysics Data System (ADS)

    Asgharzadeh, Hafez; Varble, Nicole; Meng, Hui; Borazjani, Iman

    2016-11-01

    Rupture of an intracranial aneurysm (IA) is a disease with high rates of mortality. Given the risk associated with the aneurysm surgery, quantifying the likelihood of aneurysm rupture is essential. There are many risk factors that could be implicated in the rupture of an aneurysm. However, the hemodynamic factors are believed to be the most influential ones. Here, we carry out three-dimensional high resolution simulations on human subjects IAs to test a dimensionless number, denoted as An number, to classify the flow mode. An number is defined as the ratio of the time takes the parent artery flow transports through the expansion region to the time required for vortex formation. Furthermore, we investigate the correlation of IA flow mode and WSS/OSI on the human subject IAs. Finally, we test if An number can distinguish ruptured from unruptured IAs on a database containing 204 human subjects IAs. This work was supported by National Institute Of Health (NIH) Grant R03EB014860 and the Center of Computational Research (CCR) of University at Buffalo.

  18. A method for discriminating systemic and cortical hemodynamic changes by time domain fNIRS

    NASA Astrophysics Data System (ADS)

    Zucchelli, Lucia; Spinelli, Lorenzo; Contini, Davide; Re, Rebecca; Torricelli, Alessandro

    2013-06-01

    Functional near-infrared spectroscopy (fNIRS) is a non-invasive optical technique able to measure hemodynamic response in the brain cortex. Among the different approaches the fNIRS can be based on, the time resolved one allows a straightforward relationship between the photon detection time and its path within the medium, improving the discrimination of the information content relative to the different layers the tissues are composed of. Thus absorption and scattering properties of the probed tissue can be estimated, and from them the oxy- and deoxy-hemoglobin concentration. However, an open issue in the optical imaging studies is still the accuracy in separating the superficial hemodynamic changes from those happening in deeper regions of the head and more likely involving the cerebral cortex. In fact a crucial point is the precise estimate of the time dependent pathlength spent by photons within the perturbed medium. A novel method for the calculus of the absorption properties in time domain fNIRS, based on a refined computation of photon pathlength in multilayered media, is proposed. The method takes into account the non-ideality of the measurement system (its instrument response function) and the heterogeneous structure of the head. The better accuracy in computing the optical pathlength can improve the NIRS data analysis, especially for the deeper layer. Simulations and preliminary analysis on in vivo data have been performed to validate the method and are here presented.

  19. [The impact of cardiac rehabilitation on selected hemodynamic parameters and risk in patients with heart failure].

    PubMed

    Irzmański, Robert; Kapusta, Joanna; Kapusta, Anna; Kowalski, Jan

    2014-10-01

    were classified as low risk. After a period of six months from the end of the second stage of rehabilitation analysis of individual parameters showed a further, significant improvement in groups I and II, with the highest rate of change between the studied parameters throughout the study period was observed in group II--subjected to a longer period of rehabilitation. The rehabilitation gives the favorable effect on the healing process in patients with heart failure by reducing the risk of patients undergoing systematic training.

  20. Effects of Reiki on Post-cesarean Delivery Pain, Anxiety, and Hemodynamic Parameters: A Randomized, Controlled Clinical Trial.

    PubMed

    Midilli, Tulay Sagkal; Eser, Ismet

    2015-06-01

    The aim of this study was to investigate the effect of Reiki on pain, anxiety, and hemodynamic parameters on postoperative days 1 and 2 in patients who had undergone cesarean delivery. The design of this study was a randomized, controlled clinical trial. The study took place between February and July 2011 in the Obstetrical Unit at Odemis Public Hospital in Izmir, Turkey. Ninety patients equalized by age and number of births were randomly assigned to either a Reiki group or a control group (a rest without treatment). Treatment applied to both groups in the first 24 and 48 hours after delivery for a total of 30 minutes to 10 identified regions of the body for 3 minutes each. Reiki was applied for 2 days once a day (in the first 24 and 48 hours) within 4-8 hours of the administration of standard analgesic, which was administered intravenously by a nurse. A visual analog scale and the State Anxiety Inventory were used to measure pain and anxiety. Hemodynamic parameters, including blood pressure (systolic and diastolic), pulse and breathing rates, and analgesic requirements also were recorded. Statistically significant differences in pain intensity (p = .000), anxiety value (p = .000), and breathing rate (p = .000) measured over time were found between the two groups. There was a statistically significant difference between the two groups in the time (p = .000) and number (p = .000) of analgesics needed after Reiki application and a rest without treatment. Results showed that Reiki application reduced the intensity of pain, the value of anxiety, and the breathing rate, as well as the need for and number of analgesics. However, it did not affect blood pressure or pulse rate. Reiki application as a nursing intervention is recommended as a pain and anxiety-relieving method in women after cesarean delivery. Copyright © 2015 American Society for Pain Management Nursing. Published by Elsevier Inc. All rights reserved.

  1. Hemodynamic parameters and baroreflex sensitivity during head-up tilt test in patients with neurally mediated syncope.

    PubMed

    Lee, Sung Ho; Yang, Ji Hyun; Yim, Hye Ran; Park, Jungwae; Park, Seung-Jung; Park, Kyoung-Min; On, Young Keun; Kim, June Soo

    2017-10-10

    We aimed to investigate differences in hemodynamic parameters and the role of baroreflex sensitivity (BRS) in patients with a history of neurally mediated syncope (NMS) compared with a control group. Hemodynamic parameters and BRS were continuously measured non-invasively using a Finometer at rest and during passive head-up tilt test (HUT) in patients with a history of NMS (n = 55) and a control group (n = 77). The tilting period was divided into pretest (resting supine position), initial (first 3 minutes of tilting), last (last 3 minutes of tilting), and recovery (3 minutes after tilting was complete) periods. Decrease in systolic blood pressure (-14.7 ± 15.7 vs. -7.6 ± 14.3 mmHg, P < 0.01) was more prominent and increase in total systemic peripheral resistance (TPR) was significantly smaller (67.6 ± 418.7 vs. 189.4 ± 261.0 dyn.s/cm(5) , P = 0.04) from the initial to the last period of HUT in the patient group compared with the control group. BRS was significantly higher during the pretest period (20.1 ± 10.9 vs. 13.0 ± 8.1 ms/mmHg, P < 0.01) in the patient group, while the decrease in BRS from the pretest to the initial period was greater (-8.5 ± 6.0 vs. -3.2 ± 4.1 ms/mmHg, P = 0.01). Dysfunctional BRS in response to orthostatic stress might be involved in pathological autonomic cardiac modulation of NMS. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  2. Hemodynamic changes following endotracheal intubation in patients undergoing cesarean section with general anesthesia: application of glidescope® videolaryngoscope versus direct laryngoscope.

    PubMed

    Amini, Shahram; Shakib, Majid

    2015-04-01

    Endotracheal intubation is usually associated with hemodynamic changes, especially in patients undergoing cesarean section by general anesthesia. GlideScope® videolaryngoscope (GVL) is a novel video laryngoscope, which does not need direct exposure of vocal cords and produces lesser hemodynamic changes due to lower degrees of trauma and stimuli to oropharynx than the Macintosh direct laryngoscope (MDL). The aim of this study was to compare hemodynamic changes following endotracheal intubation with GVL and MDL in patients undergoing cesarean section by general anesthesia. Seventy patients undergoing elective cesarean section by general anesthesia requiring endotracheal intubation were randomly allocated to be intubated with either GVL (n = 35) or MDL (n = 35). Systolic, diastolic and mean arterial blood pressure (MAP), as well as pulse rates, and rate pressure product (RPP) were compared at baseline, after induction of anesthesia, and after intubation at one-minute interval for five minutes between the two groups. The patients were also compared for Mallampati score, sore throat, intubation time and neonates' Apgar scores. The patients were similar regarding systolic, diastolic and mean arterial blood pressure. Pulse rate changes were significantly lower only at 1 and 3 minutes in the GVL group. The intubation times were 9.3 ± 1.4 and 10.6 ± 1.7 seconds in the MDL and GVL groups, respectively (P > 0.05). RPP was also lower in the GVL group at 1 and 2 minutes (P < 0.05) and returned to baseline afterwards. There was no significant difference between the groups for Mallampati score, sore throat and Apgar scores. Our study revealed that hemodynamic parameters with GVL are only better preserved in the first three minutes after intubation in patients undergoing elective cesarean section and patients are similar regarding intubation time, sore throat and Apgar score.

  3. Acute changes of left ventricular hemodynamics and function during percutaneous coronary intervention in patients with unprotected left main coronary artery disease.

    PubMed

    Park, Seong-Mi; Ahn, Chul-Min; Hong, Soon-Jun; Kim, Yong-Hyun; Park, Jae-Hyoung; Shim, Wan-Joo; Lim, Do-Sun

    2015-07-01

    Percutaneous coronary interventions (PCIs) are increasingly being used to treat unprotected left main coronary artery (ULMCA) lesions. However, research is sparse on the acute changes of left ventricular (LV) hemodynamics and function during PCI in patients with ULMCA stenosis. We aimed to assess the acute changes of LV function using speckle-tracking imaging during PCI in these patients. Fifteen consecutive patients who underwent elective PCI for ULMCA stenosis were enrolled. Echocardiographic studies and pressure measurement were performed at baseline, during PCI and after PCI. LMCA occlusion with a first balloon inflation induced a marked reduction in the peak positive derivative of LV pressure (dP/dt max), LV global longitudinal strain (GLS), and systolic and diastolic strain rates, and a marked increase in LV end-diastolic pressure (EDP) (all P < 0.01). During the second inflation, the degrees of LV hemodynamic and functional changes were similar to those of the first inflation, even with a higher inflation pressure. During the third inflation, the values of GLS and dP/dt max were higher than those of the second inflation (P = 0.03 and P = 0.05, respectively). After optimal PCI, dP/dt max, LVEDP, and strain parameters were improved to baseline values. LV hemodynamics and function were considerably impaired with the first ballooning during PCI for ULMCA stenosis. However, the degrees of LV hemodynamic and functional changes decreased with each successive balloon inflation, which can be explained by ischemic preconditioning. After all procedures were safely completed, LV systolic function was improved without LV diastolic stunning.

  4. Hemodynamic changes associated with a novel concentration of lidocaine HCl for impacted lower third molar surgery

    PubMed Central

    Ping, Bushara; Kiattavorncharoen, Sirichai; Durward, Callum; Im, Puthavy; Saengsirinavin, Chavengkiat

    2015-01-01

    Background The authors studied the hemodynamic effect influent by using the novel high concentration of lidocaine HCl for surgical removal impacted lower third molar. The objective of this study was to evaluate the hemodynamic change when using different concentrations of lidocaine in impacted lower third molar surgery. Methods Split mouth single blind study comprising 31 healthy patients with a mean age of 23 years (range 19-33 years). Subjects had symmetrically impacted lower third molars as observed on panoramic radiograph. Each participant required 2 surgical interventions by the same surgeon with a 3-week washout period washout period. The participants were alternately assigned one of two types of local anesthetic (left or right) for the first surgery, then the other type of anesthetic for the second surgery. One solution was 4% lidocaine with 1:100,000 epinephrine and the other was 2% lidocaine with 1:100,000 epinephrine. A standard IANB with 1.8 ml volume was used. Any requirement for additional anesthetic and patient pain intra-operation was recorded. Post-operatively, patient was instructed to fill in the patient report form for any adverse effect and local anesthetic preference in terms of intra-operative pain. This form was collected at the seven day follow up appointment. Results In the 4% lidocaine group, the heart rate increased during the first minute post-injection (P < 0.05). However, there was no significant change in arterial blood pressure during the operation. In the 2% lidocaine group, there was a significant increase in arterial blood pressure and heart rate in the first minute following injection for every procedure. When the hemodynamic changes in each group were compared, the 4% lidocaine group had significantly lower arterial blood pressure compared to the 2% lidocaine group following injection. Post-operatively, no adverse effects were observed by the operator and patient in either local anesthetic group. Patients reported less pain

  5. Availability of preoperative anxiety scale as a predictive factor for hemodynamic changes during induction of anesthesia

    PubMed Central

    Kim, Won-Sung; Byeon, Gyeong-Jo; Song, Bong-Jae

    2010-01-01

    Background The current study evaluated whether the level of preoperative anxiety assessed by the state-trait anxiety inventory (STAI) affects cardiovascular response during anesthetic induction. Furthermore, we evaluated the utility of the preoperative anxiety scale as a predictive factor for hemodynamic changes. Methods One hundred twenty patients who were scheduled to undergo elective surgery under general anesthesia were enrolled in this prospective study. The patients were asked to fill out STAI questionnaires the night before the day of surgery. For 5 minutes after tracheal intubation, changes in vital signs were recorded. The correlation between STAI scores and the percent changes in vital signs during the induction of anesthesia for each subgroup was assessed. In addition, the predictability of the 20% change in vital signs by STAI scores was analyzed using receiver operating characteristics curves. Results The state anxiety scores of patients 45 years of age or older showed a significant correlation with percent changes in mean blood pressure and heart rate, whereas the state anxiety scores in other subgroups showed no significant correlation with changes in vital signs during the induction of anesthesia. Furthermore, the state anxiety scores in patients 45 years of age or older were shown to be useful in predicting a 20% change in vital signs during anesthetic induction. Conclusions The state anxiety scores of patients 45 years of age or above could be a useful tool for predicting changes in vital signs during anesthetic induction. Thus, physician should be mindful of preoperative anxiety. PMID:20508787

  6. Two-photon microscopy of cortical NADH fluorescence intensity changes: correcting contamination from the hemodynamic response

    PubMed Central

    Baraghis, Edward; Devor, Anna; Fang, Qianqian; Srinivasan, Vivek J.; Wu, Weicheng; Lesage, Frédéric; Ayata, Cenk; Kasischke, Karl A.; Boas, David A.; Sakadžić, Sava

    2011-01-01

    Quantification of nicotinamide adenine dinucleotide (NADH) changes during functional brain activation and pathological conditions provides critical insight into brain metabolism. Of the different imaging modalities, two-photon laser scanning microscopy (TPLSM) is becoming an important tool for cellular-resolution measurements of NADH changes associated with cellular metabolic changes. However, NADH fluorescence emission is strongly absorbed by hemoglobin. As a result, in vivo measurements are significantly affected by the hemodynamics associated with physiological and pathophysiological manipulations. We model NADH fluorescence excitation and emission in TPLSM imaging based on precise maps of cerebral microvasculature. The effects of hemoglobin optical absorption and optical scattering from red blood cells, changes in blood volume and hemoglobin oxygen saturation, vessel size, and location with respect to imaging location are explored. A simple technique for correcting the measured NADH fluorescence intensity changes is provided, with the utilization of a parallel measurement of a physiologically inert fluorophore. The model is applied to TPLSM measurements of NADH fluorescence intensity changes in rat somatosensory cortex during mild hypoxia and hyperoxia. The general approach of the correction algorithm can be extended to other TPLSM measurements, where changes in the optical properties of the tissue confound physiological measurements, such as the detection of calcium dynamics. PMID:22029350

  7. Two-photon microscopy of cortical NADH fluorescence intensity changes: correcting contamination from the hemodynamic response.

    PubMed

    Baraghis, Edward; Devor, Anna; Fang, Qianqian; Srinivasan, Vivek J; Wu, Weicheng; Lesage, Frédéric; Ayata, Cenk; Kasischke, Karl A; Boas, David A; Sakadzić, Sava

    2011-10-01

    Quantification of nicotinamide adenine dinucleotide (NADH) changes during functional brain activation and pathological conditions provides critical insight into brain metabolism. Of the different imaging modalities, two-photon laser scanning microscopy (TPLSM) is becoming an important tool for cellular-resolution measurements of NADH changes associated with cellular metabolic changes. However, NADH fluorescence emission is strongly absorbed by hemoglobin. As a result, in vivo measurements are significantly affected by the hemodynamics associated with physiological and pathophysiological manipulations. We model NADH fluorescence excitation and emission in TPLSM imaging based on precise maps of cerebral microvasculature. The effects of hemoglobin optical absorption and optical scattering from red blood cells, changes in blood volume and hemoglobin oxygen saturation, vessel size, and location with respect to imaging location are explored. A simple technique for correcting the measured NADH fluorescence intensity changes is provided, with the utilization of a parallel measurement of a physiologically inert fluorophore. The model is applied to TPLSM measurements of NADH fluorescence intensity changes in rat somatosensory cortex during mild hypoxia and hyperoxia. The general approach of the correction algorithm can be extended to other TPLSM measurements, where changes in the optical properties of the tissue confound physiological measurements, such as the detection of calcium dynamics.

  8. Two-photon microscopy of cortical NADH fluorescence intensity changes: correcting contamination from the hemodynamic response

    NASA Astrophysics Data System (ADS)

    Baraghis, Edward; Devor, Anna; Fang, Qianqian; Srinivasan, Vivek J.; Wu, Weicheng; Lesage, Frédéric; Ayata, Cenk; Kasischke, Karl A.; Boas, David A.; Sakadžić, Sava

    2011-10-01

    Quantification of nicotinamide adenine dinucleotide (NADH) changes during functional brain activation and pathological conditions provides critical insight into brain metabolism. Of the different imaging modalities, two-photon laser scanning microscopy (TPLSM) is becoming an important tool for cellular-resolution measurements of NADH changes associated with cellular metabolic changes. However, NADH fluorescence emission is strongly absorbed by hemoglobin. As a result, in vivo measurements are significantly affected by the hemodynamics associated with physiological and pathophysiological manipulations. We model NADH fluorescence excitation and emission in TPLSM imaging based on precise maps of cerebral microvasculature. The effects of hemoglobin optical absorption and optical scattering from red blood cells, changes in blood volume and hemoglobin oxygen saturation, vessel size, and location with respect to imaging location are explored. A simple technique for correcting the measured NADH fluorescence intensity changes is provided, with the utilization of a parallel measurement of a physiologically inert fluorophore. The model is applied to TPLSM measurements of NADH fluorescence intensity changes in rat somatosensory cortex during mild hypoxia and hyperoxia. The general approach of the correction algorithm can be extended to other TPLSM measurements, where changes in the optical properties of the tissue confound physiological measurements, such as the detection of calcium dynamics.

  9. Power and pulsed Doppler evaluation of ovarian hemodynamic changes during diestrus in pregnant and nonpregnant bitches.

    PubMed

    Polisca, A; Zelli, R; Troisi, A; Orlandi, R; Brecchia, G; Boiti, C

    2013-01-15

    The aim of the study was to further characterize the relationship between hemodynamic changes in the ovary and luteal function in pregnant and nonpregnant bitches. Fourteen German Shepherd bitches were monitored three times a week from the first day of cytological diestrus (D1) until parturition or the end of diestrus (progesterone <2 ng/mL) by color Doppler, pulsed wave spectral Doppler, and power Doppler (PD) ultrasonography. By means of PD the total number of color pixels were calculated. The Doppler parameters evaluated were: peak systolic velocity (PSV), end diastolic velocity (EDV), and both resistive and pulsatility indices. Blood samples were collected three times a week throughout the experiment to determine progesterone (P4) concentrations. The length of diestrus in pregnant versus nonpregnant group was significantly shorter (P < 0.01; 57 ± 1 vs. 63 ± 1, respectively). By means of pulsed wave spectral Doppler the waveform showed a typical pattern of a low-resistive vessel characterized by a rapid systolic peak followed by a slow telediastolic decrease with a relatively high end-diastolic velocity. Blood flow parameters did not differ between left and right ovary. In both groups PSV and EDV showed a gradual decrease with the progress of diestrus; however, the values of PSV and EDV were significantly higher (P < 0.05) in the pregnant group versus nonpregnant group from D31 to D61 and from D49 to D58 respectively. Moreover, a significantly decrease (P < 0.05) of PSV and EDV in the pregnant group was observed from D46 to D58 and from D49 to D55, respectively. The resistive and pulsatility indices showed an increase during diestrus and the values were significantly lower (P < 0.05) in the pregnant group from D49 to D61. By means of PD, the pixel number was significantly higher (P < 0.05) in the pregnant versus nonpregnant group from D40 to D61. In particular, a significant decrease (P < 0.05) in the pixel number in the pregnant group was observed from D46 to

  10. Effect of valsalva maneuver-induced hemodynamic changes on brain near-infrared spectroscopy measurements.

    PubMed

    Tsubaki, Atsuhiro; Kojima, Sho; Furusawa, Adriane Akemi; Onishi, Hideaki

    2013-01-01

    Near-infrared spectroscopy (NIRS) is widely used to measure human brain activation on the basis of cerebral hemodynamic response. However, a limitation of NIRS is that systemic changes influence the measured signals. The purpose of this study was to clarify the relationship between NIRS signals and blood pressure during the Valsalva maneuver. Nine healthy volunteers performed a 20-s Valsalva maneuver to change their blood pressure. Changes in oxyhemoglobin (O2Hb) concentration were measured with 34 channels with an inter-optode distance of 30 mm for deep-penetration measurements (deepO2Hb) and 9 channels with an inter-optode distance of 15 mm for shallow-penetration measurements (shallowO2Hb). The difference value (diffO2Hb) between deepO2Hb and shallowO2Hb was calculated. Mean arterial pressure (MAP) was recorded by volume clamping the finger pulse, and skin blood flow changes were measured at the forehead. Pearson's correlation coefficients between deepO2Hb and MAP, shallowO2Hb and MAP, and diffO2Hb and MAP were 0.893 (P < 0.01), 0.963 (P < 0.01), and 0.831 (P < 0.01), respectively. The results suggest that regional and systemic changes in the cardiovascular state strongly influence NIRS signals.

  11. Hemodynamic and metabolic changes during exercise in calves with total artificial hearts of different sizes yet similar output.

    PubMed

    Kamohara, Keiji; Weber, Stephan; Klatte, Ryan S; Luangphakdy, Viviane; Flick, Christine R; Ootaki, Yoshio; Akiyama, Masatoshi; Cingoz, Faruk; Ootaki, Chiyo; Kopcak, Michael W; Liu, Jenny; Chen, Ji-Feng; Navia, Jose L; Smith, William A; Fukamachi, Kiyotaka

    2007-09-01

    To evaluate the effects of downsizing of the total artificial heart (TAH), we compared the anaerobic threshold (AT) values in calves with two different types of TAH (Cleveland Clinic-Nimbus TAH and the downsized MagScrew TAH). Exercise studies were performed using a treadmill in 12 calves. During the exercise, parameters to obtain the AT were measured. To evaluate the determinants of the AT, a linear regression analysis was performed between AT and potential variables. AT values from 29 studies revealed no significant differences between the two different TAHs, with no significant differences in hemodynamic or oxygen metabolic parameters. AT values correlated well with pump flow/body weight (Q) multiplied by the hemoglobin level, regardless of the TAH used. In conclusion, downsizing of the original TAH design did not reduce AT without any significant differences in hemodynamic or oxygen metabolic parameters during exercise in calves.

  12. Body Composition, Hemodynamic and Biochemical Parameters in Young Female Normal-Weight Oligo-amenorrheic and Eumenorrheic Athletes and Non-athletes

    PubMed Central

    Singhal, Vibha; de Lourdes Eguiguren, Maria; Eysenbach, Lindsey; Clarke, Hannah; Slattery, Meghan; Eddy, Kamryn; Ackerman, Kathryn E.; Misra, Madhusmita

    2014-01-01

    Aims Low-weight hypogonadal conditions such as anorexia nervosa are associated with marked changes in body composition, hemodynamic and hematological parameters, and liver enzymes. The impact of athletic activity in normal-weight adolescents with/without amenorrhea on these parameters has not been assessed. Our aim was to examine these parameters in normal-weight athletes and non-athletes and determine any associations of body composition, oligo-amenorrhea and exercise intensity. Methods We assessed vital signs, complete blood counts, liver enzymes, and regional body composition in 43 oligo-amenorrheic athletes (OAA), 24 eumenorrheic athletes (EA) and 23 non-athletes 14-21 years of age. Results BMI was lower in OAA than EA. Systolic and pulse pressure, and temperature were lowest in OAA. Blood counts did not differ among groups. AST was higher in both groups of athletes, while ALT was higher in OAA than EA and non-athletes. Total and regional fat was lower in OAA than other groups, positively associated with heart rate and inversely with liver enzymes. Conclusions Athletic activity is associated with higher AST, whereas menstrual dysfunction is associated with lower total and regional fat and higher ALT. Higher liver enzymes are associated with reductions in total and regional fat. PMID:25376841

  13. Correlation of changes in cardiac calcium channels with hemodynamics in Syrian hamster cardiomyopathy and heart failure

    SciTech Connect

    Finkel, M.S.; Marks, E.S.; Patterson, R.E.; Speir, E.H.; Steadman, K.A.; Keiser, H.R.

    1987-07-13

    The authors compared hemodynamics with (/sup 3/H)nitrendipine (calcium channel) binding to cardiac membranes from Bio 14.6 cardiomyopathic Syrian hamsters at 4 and 10 months with their F/sub 1/B controls. A 50% increase in the number (B/sub max/) of nitrendipine binding sites (calcium channels) was seen only in the 4 month old myopathic vs controls (B/sub max/ = 468 +/- 11 vs 309 +/- 10 fmol/mg prot with no change in affinity (K/sub D/) (K/sub D/ = .65 +/- .12 vs .75 +/- .14nM), while no differences in B/sub max/ or K/sub D/ were seen at 10 months (B/sub max/ = 375 +/- 9 vs 362 +/- 7 fmol/mg prot/K/sub D/ = .82 +/- .18 vs .89 +/- .17nM) myopathic vs control respectively. Hemodynamic studies revealed no significant differences in cardiac output, cardiac index, stroke volume, heart rate, mean arterial pressure, peripheral resistance, body weight, heart weight at 4 months, but a significant decrease in peripheral resistance (1120 +/- 360 vs 2080 +/- 240) increase in body weight (118 +/- 2 vs 94 +/- 2 grams) and heart weight (97 +/- 5 vs 78 +/- 2 gms/100gms body weight) in 10 month myopathic vs control animals. The authors conclude that the onset of cardiomyopathy at 4 months is associated with a selective increase in calcium channel binding sites and heart failure at 10 months is associated with a relative decrease in these sites. 14 references, 2 figures, 2 tables.

  14. Measurement of left ventricular hemodynamic parameters in closed-chest rats under control and various pathophysiologic conditions.

    PubMed

    Zimmer, H G

    1983-01-01

    A prototype of a recently developed mikro-tip pressure transducer catheter (3 French) was inserted into the left ventricle of closed-chest rats via the right carotid artery. In thiobutabarbital-sodium anesthesia, heart rate (409 +/- 7 beats/min), left ventricular systolic pressure (LVSP: 142 +/- 4 mm Hg) and the maximal rate of rise of left ventricular pressure (LV dP/dtmax: 6073 +/- 187 mm Hg/sec, mean values +/- SEM, n = 19) were measured. The baroreceptor reflex was intact under these experimental conditions. In closed-chest guinea pigs, all functional parameters determined were lower (heart rate: 271 +/- 11 beats/min; LVSP: 94 +/- 6 mm Hg; LV dP/dtmax: 3248 +/- 295 mm Hg/sec, mean values +/- SEM, n = 9). To test the applicability of the new catheter tip manometer, cardiac hemodynamic parameters were determined in rats under various pathophysiologic conditions: Several periods of asphyxia were followed by progressive depressions in heart rate, LVSP and LV dP/dtmax, and acute as well as chronic stimulation with catecholamines (noradrenaline and isoproterenol) and with triiodothyronine was characterized by a pronounced positive inotropic and chronotropic effect. The technique described has many potential applications in cardiovascular studies on intact small laboratory animals.

  15. An impedance device for study of multisegment hemodynamic changes during orthostatic stress

    NASA Astrophysics Data System (ADS)

    Montgomery, L. D.; Hanish, H. M.; Marker, R. A.

    1989-11-01

    Definition of multisegment hemodynamic changes that take place in the body would provide a more complete understanding of the physiologic responses to various orthostatic stress techniques. A self-contained impedance device is described which may be used to measure the electrical transmission characteristics produced by blood flow and volume changes in six segments of the human body during head-up tilt, bed rest, and lower body negative pressure. The device consists of a module that contains the electronics for the impedance system, a separate controller/multiplexer, a personal computer interface/analog to digital conversion/power supply system, and the associated computer control softwave. The instrument is linear over a range of 0 to 200 ohms; provides analog outputs of base impedance, phase angle, pulsatile impedance change, and the first derivative of the pulsatile impedance changes; and can be used to automatically record basal impedance values into spread-sheet format with cycle times between 12 s and 1 h. Typical results are presented to illustrate its application in aerospace research.

  16. Echocardiographic Evaluation of Changes in Cardiac Hemodynamics and Loading Conditions after Transthoracic Minimally Invasive Device Closure of Atrial Septal Defect

    PubMed Central

    Cao, Hua; Zhang, Gui-Can; Chen, Liang-Wan; Hu, Yun-Nan

    2015-01-01

    Purpose To evaluate transthoracic minimally invasive device closure of atrial septal defects by performing transthoracic echocardiography to measure changes in cardiac hemodynamics and loading conditions. Methods Between January 2012 and December 2012, we performed transthoracic minimally invasive device closure of atrial septal defects in 95 patients with secundum atrial septal defects (ASD), and performed transthoracic echocardiography to measure blood flow velocities at the tricuspid valve orifice and at the pulmonary valve orifice, sizes of the left and right atria and ventricles, right ventricular fractional area change, right ventricular Tei index, three-dimensional right ventricular ejection fraction, tricuspid annular plane systolic excursion and left ventricular ejection fractions before the procedure and 1 week, 3 months, and 1 year post-procedure. Results Varying degrees of improvement were observed post-procedure at later time points. The maximum blood flow velocity at the pulmonary valve orifice, mean flow velocity, velocity-time integral, and A peak and E peak blood flow velocity at the tricuspid valve orifice decreased significantly post-procedure (P<0.05). In 3 months and 1 year’s follow-up, the inner diameter of the middle portion of the pulmonary artery, and diameters of the right atrium and right ventricle decreased significantly post-procedure (P<0.05). The diameters of the left atrium and left ventricle increased after the procedure (P<0.05). One week after the procedure, the right ventricular fractional area change, three-dimensional right ventricular ejection fraction, right ventricular Tei index and tricuspid annular plane systolic excursion had significantly reduced compared with the preoperative data (P<0.05). While these four parameters were still decreased at the 3 months and at 1 year’s follow-up, but the differences were not statistically significant compared with the 1 week’s postoperative data (P>0.05). One week post

  17. Cerebral hemodynamic and metabolic changes caused by brain retraction after aneurysmal subarachnoid hemorrhage.

    PubMed

    Yundt, K D; Grubb, R L; Diringer, M N; Powers, W J

    1997-03-01

    The cerebral hemodynamic and metabolic effects of aneurysmal subarachnoid hemorrhage are complex. To investigate the impact of surgical retraction, we analyzed position emission tomography (PET) studies that measured the regional cerebral metabolic rate for oxygen, regional oxygen extraction fraction, and regional cerebral blood flow in four patients before and after right frontotemporal craniotomies for clipping of ruptured anterior circulation aneurysms. Preoperative studies were conducted 1 day before surgery and postoperative studies 6 to 17 days after surgery. No patient had hydrocephalus or intracerebral hematoma. At the time of the second PET study, none of the patients had signs of clinical vasospasm. Regional measurements were obtained from the right ventrolateral frontal and anterior temporal regions corresponding to the area of retraction and compared to the same regions in the opposite hemisphere. To establish a quantitative means to differentiate between hemodynamic and metabolic changes related to arterial vasospasm and those caused by brain retraction, we studied a second group of preoperative patients, who had undergone PET during angiographic and clinical vasospasm. There was a 45% reduction in regional cerebral metabolic rate for oxygen (1.87 +/- 0.22 to 1.04 +/- 0.28 ml 100 g-1 min-1) and 32% reduction in regional oxygen extraction fraction (0.41 +/- 0.04 to 0.28 +/- 0.03) in the region of retraction but no change in the opposite hemisphere (paired t test; P = 0.042 and 0.003, respectively). There was no change in regional cerebral blood flow in any region. Brain retraction produced a focal area of tissue injury at the site of retractor blade placement, as compared to more diffuse vascular territory changes produced by vasospasm. This reduction in the cerebral metabolic rate of oxygen and the oxygen extraction fraction indicates a primary reduction in metabolism and uncoupling of flow and metabolism (luxury perfusion). Similar findings of luxury

  18. Vaginal hemodynamic changes during sexual arousal in a rat model by diffuse optical spectroscopy (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Jeong, Hyeryun; Seong, Myeongsu; Lee, Hyun-Suk; Park, Kwangsung; Kim, Jae Gwan

    2017-02-01

    Not only men suffer from sexual dysfunction, but the number of women who have sexual dysfunction rises. Therefore, it is necessary to develop an objective diagnostic technique to examine the sexual dysfunction of female patients, who are afflicted with the disorders. For this purpose, we developed a diffuse optical spectroscopy (DOS) probe to measure the change of oxy-, deoxy-, and total hemoglobin concentration along with blood flow from vaginal wall of female rats. A cylindrical stainless steel DOS probe with a diameter of 3 mm was designed for the vaginal wall of rats which consisted of two lasers (785 and 850nm) and two spectrometers with a separation of 2 mm. A thermistor was placed on the top of the probe to measure the temperature change from vaginal wall during experiments. A modified Beer-Lambert's law is utilized to acquire the changes of oxy-, deoxy-, and total hemoglobin, and blood flow information is obtained by diffuse speckle contrast analysis technique. For the experiments, Sprague Dawley ( 400 g) female rats were divided into two groups (control and vaginal dryness model). Vaginal oxygenation, blood flow and temperature were continuously monitored before and after sexual around induced by apomorphine. After the measurement, histologic examination was performed to support the results from DOS probe in the vaginal wall. The hemodynamic information acquired by the DOS probe can be utilized to establish an objective and accurate standard of the female sexual disorders.

  19. [The pulmonary hemodynamic changes under experimental myocardial ischemia in rabbits following beta-adrenoreceptors blockade].

    PubMed

    Evlakhov, V I; Poiasov, I Z

    2011-08-01

    In acute experiments in anesthetized rabbits, changes of the pulmonary hemodynamics following myocardial ischemia in the region of the descendent left coronary artery were studied as well as in control animals and after the blockade of beta-adrenoreceptors. The myocardial ischemia decreased the left ventricular myocardial contractility, cardiac output and arterial pressure, decreased the pulmonary artery pressure and flow. Following myocardial ischemia, the pulmonary artery pressure decreased less than pulmonary artery blood flow as the result of elevating of the left atrial pressure, meanwhile pulmonary vascular resistance was not changed. Following myocardial ischemia in animals after the blockade of the beta-adrenoreceptors, the pulmonary flow decreased the same as in control animals. However, the pulmonary artery pressure was decreased twofold more significantly than in control animals, and its diminishing was in the same degree as the pulmonary artery flow. Following myocardial ischemia after the blockade of the beta-adrenoreceptors, the pulmonary vascular resistance decreased whereas the left atrial pressure did not change significantly because the myocardial contractility decreased less than in control animals.

  20. Comparative Study of Hemodynamics Electrolyte and Metabolic Changes During Prone and Complete Supine Percutaneous Nephrolithotomy

    PubMed Central

    Khoshrang, Hosein; Falahatkar, Siavash; Ilat, Sara; Akbar, Manzar Hossein; Shakiba, Maryam; Farzan, Alireza; Herfeh, Nadia Rastjou; Allahkhah, Aliakbar

    2012-01-01

    Background Nowadays Percutaneous Nephrolithotomy (PCNL) is performed in prone and supine positions. Physiologic solutions should be used to irrigate during PCNL. Irrigation can cause hemodynamic, electrolyte and acid-base changes during PCNL. Objectives The current study aimed to compare the electrolyte, hemodynamic and metabolic changes of prone and complete supine PCNL. Patients and Methods It was a randomized clinical trial study on 40 ASA class I and II patients. Twenty of patients underwent prone PCNL (Group A) and the other twenty underwent complete supine PCNL (Group B). The two groups received the same premedication and induction of anesthesia. Blood pressure (systolic, diastolic and mean) and pulse rate were recorded before, during and after anesthesia and Hb, Hct, BUN, Cr, Na, and K were also measured before and after operation in the two groups. The volume of irrigation fluid, total effluent fluid (the fluid in the bucket and the gazes) and volume of absorbed fluid were measured. Results There were no significant differences in Na, K, BUN, Cr, Hb and Hct between the two groups. Absorption volume was significantly different between the two groups (335 ± 121.28 mL in group A and 159.45 ± 73.81 mL in group B, respectively) (P = 0.0001). The mean anesthesia time was significantly different between the two groups (P = 0.012). There was a significant difference in bleeding volume between supine and prone PCNL (270.4 ± 229.14 in group A and 594.2 ± 290 in group B, respectively) (P = 0.0001). Mean systolic blood pressure during operation and recovery was 120.2 ± 10.9 and 140.7 ± 25.1 in group B, and 113.4 ± 6.4 and 126.2 ± 12.7 in group A, respectively. Systolic blood pressure between the two groups during operation and recovery was significantly different (P = 0.027 and P = 0.022, respectively). Mean diastolic blood pressure in supine group during operation and recovery was 80.53 ± 7.57 and 95.75 ± 17.48, and 73.95 ± 3.94 and 83.4 ± 12.54 in prone

  1. Fetal Hemodynamic Parameters in Low Risk Pregnancies: Doppler Velocimetry of Uterine, Umbilical, and Middle Cerebral Artery

    PubMed Central

    Dertkigil, M. S.; Pereira, S. L.; Bennini, J. R.; Mayrink, J.

    2016-01-01

    Objective. To elaborate curves of longitudinal reference intervals of pulsatility index (PI) and systolic velocity (SV) for uterine (UtA), umbilical (UA), and middle cerebral arteries (MCA), in low risk pregnancies. Methods. Doppler velocimetric measurements of PI and SV from 63 low risk pregnant women between 16 and 41 weeks of gestational age. Means (±SD) for intervals of gestational age and percentiles 5, 50, and 95 were calculated for each parameter. The Intraclass Correlation Coefficients (ICC) were also estimated for assessing intra- and intervariability of measurements. Results. Mean PI of UtA showed decreasing values during pregnancy, but no regular pattern was identified for mean SV. For UA, PI decreased and SV increased along gestation. MCA presented PI increasing values until 32–35 weeks. SV showed higher levels with increasing gestation. High ICC values indicated good reproducibility. Conclusions. Reference intervals for the assessment of SV and PI of UtA, UA, and MCA were established. These reference intervals showed how a normal pregnancy is expected to progress regarding these Doppler velocimetric parameters and are useful to follow high risk pregnancies. The comparison between results using different curves may provide insights about the best patterns to be used. PMID:27957524

  2. The hemodynamic changes in the human prefrontal cortex during the Flanker and Simon tasks: a fNIRS study

    NASA Astrophysics Data System (ADS)

    Yuan, Zhen; Lin, Xiaohong

    2016-03-01

    Functional near-infrared spectroscopy (fNIRS) is a low-cost, portable and noninvasive functional neuroimaging technique by measuring the change in the concentrations of oxyhemoglobin (HbO) and deoxyhemoglobin (HbR). The aim of present study is to reveal the different brain activity pattern of adult subjects during the completion of flanker and Simon tasks underlying the congruent and incongruent test conditions so as to identify the basic neural mechanism of inhibitory control in executive function. In the study, we utilized fNIRS to explore the hemodynamic changes in the prefrontal cortex and our imaging results suggested that there were notable differences for the hemodynamic responses between the flank and Simon task. A striking difference is that for the flank task, the increase in the HbO concentration during incongruent trials was larger than that during congruent trials for the channels across middle frontal cortex while for the Simon task, the hemodynamic response was stronger for the congruent condition compared to that from the incongruent one. Interestingly, the hemodynamic response exhibited similar task-related activation in the superior frontal cortex for both the congruent and incongruent conditions. Further, independent component analysis showed that different brain activation patterns were identified to accomplish different inhibitory control tasks underlying the congruent and incongruent conditions.

  3. Influence of stenosis on hemodynamic parameters in the realistic left coronary artery under hyperemic conditions.

    PubMed

    Kamangar, Sarfaraz; Badruddin, Irfan Anjum; Badarudin, A; Nik-Ghazali, N; Govindaraju, Kalimuthu; Salman Ahmed, N J; Yunus Khan, T M

    2017-03-01

    The current study investigates the hyperemic flow effects on heamodynamics parameters such as velocity, wall shear stress in 3D coronary artery models with and without stenosis. The hyperemic flow is used to evaluate the functional significance of stenosis in the current era. Patients CT scan data of having healthy and coronary artery disease was chosen for the reconstruction of 3D coronary artery models. The diseased 3D models of coronary artery shows a narrowing of >50% lumen area. Computational fluid dynamics was performed to simulate the hyperemic flow condition. The results showed that the recirculation zone was observed immediate to the stenosis and highest wall shear stress was observed across the stenosis. The decrease in pressure was found downstream to the stenosis as compared to the coronary artery without stenosis. Our analysis provides an insight into the distribution of wall shear stress and pressure drop, thus improving our understanding of hyperemic flow effect under both conditions.

  4. In vivo measure of neonate brain optical properties and hemodynamic parameters by time-domain near-infrared spectroscopy.

    PubMed

    Spinelli, Lorenzo; Zucchelli, Lucia; Contini, Davide; Caffini, Matteo; Mehler, Jacques; Fló, Ana; Ferry, Alissa L; Filippin, Luca; Macagno, Francesco; Cattarossi, Luigi; Torricelli, Alessandro

    2017-10-01

    By exploiting a multichannel portable instrument for time-domain near-infrared spectroscopy (TD-NIRS), we characterized healthy neonates' brains in term of optical properties and hemodynamic parameters. In particular, we assessed the absolute values of the absorption and reduced scattering coefficients at two wavelengths, together with oxy-, deoxy- and total hemoglobin concentrations, and the blood oxygen saturation of the neonates' brains. In this study, 33 healthy full-term neonates were tested, obtaining the following median values: 0.28 and [Formula: see text] for [Formula: see text] at 690 and 820 nm, respectively; 5.8 and [Formula: see text] for [Formula: see text] at 690 and 820 nm, respectively; [Formula: see text] for [Formula: see text]; [Formula: see text] for [Formula: see text]; [Formula: see text] for [Formula: see text]; 72% for [Formula: see text]. In general, the agreement of these values with the sparse existing literature appears not always consistent. These findings demonstrate the first measurements of optical properties of the healthy neonate brain using TD-NIRS and show the need for clarification of optical properties across methods and populations.

  5. Cerebral oxygenation and hemodynamic changes during infant cardiac surgery: measurements by near infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    du Plessis, Adre J.; Volpe, Joseph J.

    1996-10-01

    Despite dramatic advances in the survival rate among infants undergoing cardiac surgery for congenital heart disease, the incidence of brain injury suffered by survivors remains unacceptably high. This is largely due to our limited understanding of the complex changes in cerebral oxygen utilization and supply occurring during the intraoperative period as a result of hypothermia, neuroactive drugs, and profound circulatory changes. Current techniques for monitoring the adequacy of cerebral oxygen supply and utilization during hypothermic cardiac surgery are inadequate to address this complex problem and consequently to identify the infant at risk for such brain injury. Furthermore, this inability to detect imminent hypoxic- ischemic brain injury is likely to become all the more conspicuous as new neuroprotective strategies, capable of salvaging 'insulated' neuronal tissue form cell death, enter the clinical arena. Near infrared spectroscopy is a relatively new, noninvasive, and portable technique capable of interrogating the oxygenation and hemodynamics of tissue in vivo. These characteristics of the technique have generated enormous interest among clinicians in the ability of near infrared spectroscopy to elucidate the mechanisms of intraoperative brain injury and ultimately to identify infants oat risk for such injury. This paper reviews the experience with this technique to date during infant cardiac surgery.

  6. Carotid endarterectomy (CE) of the internal carotid artery (ICA) with and without patch angioplasty: comparison of hemodynamical and morphological parameters.

    PubMed

    Hirschl, M; Bernt, R A; Hirschl, M M

    1989-01-01

    The aim of this study was to show, if patch angioplasty or direct closure of the blood vessel following carotid endarterectomy of the ICA resulted in any hemodynamical or morphological differences. Studies were carried out in eighteen and twenty patients, respectively within an average postoperative period of twenty-six month. All patients were examined with continuous-wave Doppler ultrasound, multi-channel pulse Doppler ultrasound and Duplex ultrasonography scanning. Comparing the two groups, differences are predominantly found at or near the site of the endarterectomized segment. Patients who received PTFE (Gore-Tex) patch angioplasty to close the arteriotomy, show in about 50% of all cases a dilatation--pantaloon effect (10)--at the carotid bifurcation (lumina greater than 1.1 cm) when investigating the vessel lumen with duplex sonography. This results in a statistical significant increase in turbulent flow disturbances at the bulb and the origin of the ICA. Furthermore, ICA flow velocity patterns after the endarterectomy point are still within the normal range when compared with patients not receiving a patch plasty, but still significantly elevated. Changes of the vessel wall, as such as intima elevation and intraluminal deposits are more frequently found distal to the endarterectomized segment and do obviously reduce the lumen. However, changes of flow volumina were not quantifiable. Atherosclerotic patients who underwent surgical treatment show as a characteristic finding due to atherosclerosis, a less laminar flow-pattern within the whole extracranial area, when compared with a normal healthy population.

  7. Compliant model of a coupled sequential coronary arterial bypass graft: effects of vessel wall elasticity and non-Newtonian rheology on blood flow regime and hemodynamic parameters distribution.

    PubMed

    Kabinejadian, Foad; Ghista, Dhanjoo N

    2012-09-01

    We have recently developed a novel design for coronary arterial bypass surgical grafting, consisting of coupled sequential side-to-side and end-to-side anastomoses. This design has been shown to have beneficial blood flow patterns and wall shear stress distributions which may improve the patency of the CABG, as compared to the conventional end-to-side anastomosis. In our preliminary computational simulation of blood flow of this coupled sequential anastomoses design, the graft and the artery were adopted to be rigid vessels and the blood was assumed to be a Newtonian fluid. Therefore, the present study has been carried out in order to (i) investigate the effects of wall compliance and non-Newtonian rheology on the local flow field and hemodynamic parameters distribution, and (ii) verify the advantages of the CABG coupled sequential anastomoses design over the conventional end-to-side configuration in a more realistic bio-mechanical condition. For this purpose, a two-way fluid-structure interaction analysis has been carried out. A finite volume method is applied to solve the three-dimensional, time-dependent, laminar flow of the incompressible, non-Newtonian fluid; the vessel wall is modeled as a linearly elastic, geometrically non-linear shell structure. In an iteratively coupled approach the transient shell equations and the governing fluid equations are solved numerically. The simulation results indicate a diameter variation ratio of up to 4% and 5% in the graft and the coronary artery, respectively. The velocity patterns and qualitative distribution of wall shear stress parameters in the distensible model do not change significantly compared to the rigid-wall model, despite quite large side-wall deformations in the anastomotic regions. However, less flow separation and reversed flow is observed in the distensible models. The wall compliance reduces the time-averaged wall shear stress up to 32% (on the heel of the conventional end-to-side model) and somewhat

  8. Real-time monitoring of hemodynamic changes in tumor vessels during photoimmunotherapy using optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Liang, Chia-Pin; Nakajima, Takahito; Watanabe, Rira; Sato, Kazuhide; Choyke, Peter L.; Chen, Yu; Kobayashi, Hisataka

    2014-09-01

    Photoimmunotherapy (PIT) is a cell-specific cancer therapy based on an armed antibody conjugate that induces rapid and highly selective cancer cell necrosis after exposure to near-infrared (NIR) light. The PIT treatment also induces the superenhanced permeability and retention effect, which allows high concentrations of nanoparticles to accumulate in the tumor bed. In our pilot studies, optical coherence tomography (OCT) reveals dramatic hemodynamic changes during PIT. We developed and applied speckle variance analysis, Doppler flow measurement, bulk motion removal, and automatic region of interest selection to quantify vessel diameter and blood velocity within tumors in vivo. OCT imaging reveals that blood velocity in peripheral tumor vessels quickly drops below the detection limit while the vessel lumen remains open (4 vessels from 3 animals). On the other hand, control tumor vessels (receive NIR illumination but no PIT drug) do not show the sustained blood velocity drop (5 vessels from 3 animals). Ultraslow blood velocity could result in a long drug circulation time in tumor. Increase of the blood pool volume within the central tumor (shown in histology) may be the leading cause of the periphery blood velocity drop and could also increase the drug pool volume in tumor vessels.

  9. [Changes in cerebral hemodynamics in chronic users of "PACO" and cocaine: case-control study].

    PubMed

    Previgliano, Ignacio; Cortese, Silvia; Di Nardo, Victoria; Lara, Enrique; Da Ré, Sabrina; Villareal, Orlando; Poliszuk, Julieta; Fernández, María E; Quinteros, Mónica; Damín, Carlos; Nuñez, Myriam

    2014-01-01

    To assess if there are changes in brain hemodynamics evaluated by means of transcranial doppler's flow velocity, pulsatile index and cerebral perfusion pressure, between cocaine chronic abusers and healthy volunteers. Prospective, case and control, observational study. Sex, age, user history, vital signs and transcranial doppler findings.Statistical analysis was performed by means of normality test, Wilcoxon's test for non parametric samples and T Student test. Fifty-three abusers and 35 healthy volunteers were studied. Statistical differences were found for a diminish in age(p=0.008) and cerebral perfusion pressure in all cerebral arteries (p

  10. Real-time monitoring of hemodynamic changes in tumor vessels during photoimmunotherapy using optical coherence tomography.

    PubMed

    Liang, Chia-Pin; Nakajima, Takahito; Watanabe, Rira; Sato, Kazuhide; Choyke, Peter L; Chen, Yu; Kobayashi, Hisataka

    2014-09-01

    Photoimmunotherapy (PIT) is a cell-specific cancer therapy based on an armed antibody conjugate that induces rapid and highly selective cancer cell necrosis after exposure to near-infrared (NIR) light. The PIT treatment also induces the superenhanced permeability and retention effect, which allows high concentrations of nanoparticles to accumulate in the tumor bed. In our pilot studies, optical coherence tomography (OCT) reveals dramatic hemodynamic changes during PIT. We developed and applied speckle variance analysis, Doppler flow measurement, bulk motion removal, and automatic region of interest selection to quantify vessel diameter and blood velocity within tumors in vivo. OCT imaging reveals that blood velocity in peripheral tumor vessels quickly drops below the detection limit while the vessel lumen remains open (4 vessels from 3 animals). On the other hand, control tumor vessels (receive NIR illumination but no PIT drug) do not show the sustained blood velocity drop (5 vessels from 3 animals). Ultraslow blood velocity could result in a long drug circulation time in tumor. Increase of the blood pool volume within the central tumor (shown in histology) may be the leading cause of the periphery blood velocity drop and could also increase the drug pool volume in tumor vessels.

  11. EFFECTS OF DEXAMETHASONE AND PHENIRAMINE MALEATE ON HEMODYNAMIC AND RESPIRATORY PARAMETERS AFTER CEMENTATION IN CEMENTED PARTIAL HIP PROSTHESIS.

    PubMed

    Yektaş, Abdulkadir; Gümüş, Funda; Totoz, Tolga; Gül, Nurten; Erkalp, Kerem; Alagöl, Ayşin

    2015-02-01

    To prevent hemodynamic and respiratory changes that are likely to occur during cementation in partial hip prosthesis by prophylactic use of pheniramine maleate and dexamethasone. The study included 40 patients aged between 60 and 85 years with an American Society ofAnesthesiologists (ASA) grade of II-III who underwent partial hip prosthesis. Just after spinal anesthesia, 4 mL normal saline was pushed in patients in Group S, whereas 45.5 mg pheniramine maleate and 8 mg dexamethasone mixture was pushed intravenously in a total volume of 4 mL in patients in Group PD. Amounts of atropine and adrenaline administered after cementation were significantly higher in Group S than in Group PD (P < 0.05). There was a significant difference between SpO2 values before and after cementation in Group S; SpO2 value was lower after cementation (P < 0.05) except for 1. min after cementation. SpO2 value increased 1 min after cementation (P = 0.031) CONCLUSION: Prophylactic use of pheniramine maleate and dexamethasone in partial hip prosthesis led to an increase in SpO2 value and a decrease in the utilization of adrenaline and atropine after cementation.

  12. Importance of hemodynamic forces as signals for exercise-induced changes in endothelial cell phenotype.

    PubMed

    Laughlin, M Harold; Newcomer, Sean C; Bender, Shawn B

    2008-03-01

    Current evidence indicates that the ability of physical activity to sustain a normal phenotype of arterial endothelial cells (ECs) plays a central role in the beneficial effects of exercise (Ex) on atherosclerotic disease. Here we evaluate the strength of evidence that shear stress (SS) and/or circumferential wall stress (stretch) are the primary signals, produced by bouts of Ex, that signal altered gene expression in arterial ECs, thereby resulting in a less atherogenic EC phenotype. Current literature indicates that SS is a signal for expression of antiatherogenic genes in cultured ECs, in ECs of isolated arteries, and in ECs of arteries in intact animals. Furthermore, SS levels in the arteries of humans during Ex are in the range that produces beneficial changes. In contrast, complex flow profiles within recirculation zones and/or oscillatory flow patterns can cause proatherogenic gene expression in ECs. In vivo evidence indicates that Ex decreases oscillatory flow/SS in some portions of the arterial tree but may increase oscillatory flow in other areas of the arterial tree. Circumferential wall stress can increase expression of some beneficial EC genes as well, but circumferential wall stress also increases production of reactive oxygen species and increases the expression of adhesion factors and other proatherogenic genes. Interactions of arterial pressure and fluid SS play an important role in arterial vascular health and likely contribute to how Ex bouts signal changes in EC gene expression. It is also clear that other local and circulating factors interact with these hemodynamic signals during Ex to produce the healthy arterial EC phenotype. We conclude that available evidence suggests that exercise signals formation of beneficial endothelial cell phenotype at least in part through changes in SS and wall stretch in the arteries.

  13. The dynamic changes of plasma neuropeptide y and neurotensin and their role in regulating cerebral hemodynamics in neonatal hypoxic-ischemic encephalopathy.

    PubMed

    Liu, Jing; Zhao, Juan; Di, Ying-Fen; Guo, Xiu-Xia; Zhai, Gui-Rong; Huang, Xing-Hua

    2007-08-01

    Hypoxic-ischemic encephalopathy (HIE) is a common cause of neonatal encephalopathy and is one of the most important causes of neonatal death and disabilities, especially those infants with moderate to severe encephalopathy. However, the pathogenesis of HIE still remains unclear. The purpose of this study was to explore the dynamic changes in plasma neuropeptide Y (NPY) and neurotensin (NT) as well as their role in regulating cerebral hemodynamics in HIE patients. The plasma levels of NPY and NT in the umbilical artery and peripheral blood on the first, third, and seventh days after birth in 40 term infants with HIE and 40 healthy controls were measured using radioimmunoassay. On the first day of life, the blood samples were collected immediately when ultrasound examinations were finished. The ultrasound transducer was placed on the temporal fontanelle to detect the hemodynamic parameters of the middle cerebral artery, including peak systolic flow velocity, end-diastolic flow velocity, time-average mean velocity, pulsatility index, and resistance index (RI) in both groups were measured by pulse Doppler ultrasound in the first day after birth. The relationship between RI and NPY or NT was analyzed by linear regression analysis. NPY levels in umbilical blood ([mean +/- standard deviation] 615.5 +/- 130.7 ng/L) and first-day peripheral blood (355.9 +/- 57.4 ng/L) in neonates with HIE were significantly higher than those in normal newborns' blood (199.1 +/- 63.2 and 214.4 +/- 58.0 ng/L, respectively; P < 0.01). NPY levels in HIE neonates then declined to control levels on the third day after birth ( P > 0.05). However, the levels of plasma NT in umbilical blood and peripheral blood were much higher in the HIE group than those in normal newborns during the first week ( P < 0.01). The results of Doppler ultrasound examinations showed that cerebral blood flow velocity significantly decreased, whereas RI increased markedly in HIE patients compared with healthy controls ( P

  14. A Novel Index Using Ankle Hemodynamic Parameters to Assess the Severity of Peripheral Arterial Disease: A Pilot Study.

    PubMed

    Tanno, Jun; Gatate, Yodo; Kasai, Takatoshi; Nakano, Shintaro; Senbonmatsu, Takaaki; Sato, Osamu; Ichioka, Shigeru; Kuro-O, Makoto; Nishimura, Shigeyuki

    2016-01-01

    In peripheral arterial disease (PAD) of the lower extremities, the presence of flow-limiting stenoses can be objectively detected by the ankle-brachial index (ABI). However, the severity of ischemic symptoms is not necessarily associated with the ABI value. Atherosclerotic plaque in lower extremity PAD induces ankle arterial stiffness and reduces ankle vascular resistance, which may decrease ankle blood flow and cause ischemic symptoms. We hypothesized that the ankle hemodynamic index (AHI), defined as the ratio of ankle arterial stiffness to ankle vascular resistance, could be used to assess the blood supply deficiency in a diseased lower limb in patients with PAD. The 85 consecutive patients with PAD who were retrospectively analyzed in this study had Rutherford grade 1 to grade 6 ischemia diagnosed as PAD and significant stenotic lesions (>50% diameter stenosis) of the lower extremity on contrast angiography. The AHI was calculated as the product of the ankle pulse pressure and the ratio of heart rate to ankle mean arterial pressure (ankle pulse pressure × heart rate/ankle mean arterial pressure). The Rutherford grade was significantly correlated with the AHI (r = 0.50, P < 0.001), but not with the ABI (r = 0.07, P = 0.52). Multiple ordinal regression analysis showed that anemia (odds ratio 0.66, P = 0.002) and AHI (odds ratio 1.04, P = 0.02) were independently associated with Rutherford grade. Our study shows that AHI, a novel parameter based on the ABI measurement, is well correlated with ischemic symptoms, and may be a useful means to assess the arterial blood supply of the lower extremities of patients with PAD.

  15. The Relationship between Serum Oxalic Acid, Central Hemodynamic Parameters and Colonization by Oxalobacter formigenes in Hemodialysis Patients.

    PubMed

    Gulhan, Baris; Turkmen, Kultigin; Aydin, Merve; Gunay, Murat; Cıkman, Aytekin; Kara, Murat

    2015-06-01

    Elevated pulse wave velocity (PWV) and central aortic blood pressures are independent predictors of increased cardiovascular morbidity and mortality in hemodialysis (HD) patients. Oxalic acid is a uremic retention molecule that is extensively studied in the pathogenesis of calcium oxalate stones. Oxalobacter formigenes, a member of the colon microbiota, has important roles in oxalate homeostasis. Data regarding the colonization by and the exact role of O. formigenes in the pathogenesis of oxalic acid metabolism in HD patients are scant. Hence, we aimed to determine the relationship between fecal O. formigenes colonization, serum oxalic acid and hemodynamic parameters in HD patients with regard to the colo-reno-cardiac axis. Fifty HD patients were enrolled in this study. PWV and central aortic systolic (cASBP) and diastolic blood pressures (cADBP) were measured with a Mobil-O-Graph (I.E.M. GmbH, Stolberg, Germany). Serum oxalic acid levels were assessed by ELISA, and fecal O. formigenes DNA levels were isolated and measured by real-time PCR. Isolation of fecal O. formigenes was found in only 2 HD patients. One of them had 113,609 copies/ml, the other one had 1,056 copies/ml. Serum oxalic acid levels were found to be positively correlated with PWV (r = 0.29, p = 0.03), cASBP (r = 0.33, p = 0.001) and cADBP (r = 0.42, p = 0.002) and negatively correlated with LDL (r = -0.30, p = 0.03). In multivariate linear regression analysis, PWV was independently predicted by oxalic acid, glucose and triglyceride. This is the first study that demonstrates the absence of O. formigenes as well as a relation between serum oxalic acid and cASBP, cADBP and PWV in HD patients. Replacement of O. formigenes with pre- and probiotics might decrease serum oxalic acid levels and improve cardiovascular outcomes in HD patients.

  16. Early hemodynamic changes at the microcirculatory level and effects of mannitol following focal cryogenic injury.

    PubMed

    Vinas, F C; Dujovny, M; Hodgkinson, D

    1995-12-01

    Changes in cerebral blood flow due to infusion of hyperosmolar solutions are of considerable importance in states of raised intracranial pressure. The present study was aimed to evaluate the effects of mannitol on the cerebral microcirculation, in a model of vasogenic brain edema. A right fronto-parietal craniotomy was performed in 30 adult Sprague-Dawley rats. Vasogenic edema was produced by placing dry-ice over the dura for 1 min. The cortical blood flow was monitored for 120 min using a laser-Doppler flowmeter (Perimed, Stockholm, Sweden), and graphics were recorded using a personal computer. Animals were randomly divided into three groups: group 1 (control group) received no mannitol; group 2 was treated with a bolus injection of 20% mannitol (1 mg kg-1); group 3 received the same dose over a 30 min infusion. Mean blood pressure, temperature, and respiratory rate were continuously monitored. At the end of the procedure, an intravenous injection of Evan's blue 2% was given. Results were compared by using repeated measures of analysis of variance and a two-sample t-test at each time. After the production of a cryogenic injury, we found a marked decrease in the cerebral blood flow, whereas mannitol partially reversed that effect. There was not significant difference between groups 2 and 3; however, there was a significant difference between mannitol and control groups after 15 min. During the early phase of vasogenic edema, early use of mannitol did not increase the blood flow, but stabilized it, preventing further decrease. Laser-Doppler flowmetry is a valuable method for continuous estimation of hemodynamic changes in the cerebral microcirculation.

  17. Monitoring Local Regional Hemodynamic Signal Changes during Motor Execution and Motor Imagery Using Near-Infrared Spectroscopy

    PubMed Central

    Iso, Naoki; Moriuchi, Takefumi; Sagari, Akira; Kitajima, Eiji; Iso, Fumiko; Tanaka, Koji; Kikuchi, Yasuki; Tabira, Takayuki; Higashi, Toshio

    2016-01-01

    The aim of this study was to clarify the topographical localization of motor-related regional hemodynamic signal changes during motor execution (ME) and motor imagery (MI) by using near-infrared spectroscopy (NIRS), as this technique is more clinically expedient than established methods (e.g., fMRI). Twenty right-handed healthy subjects participated in this study. The experimental protocol was a blocked design consisting of 3 cycles of 20 s of task performance and 30 s of rest. The tapping sequence task was performed with their fingers under 4 conditions: ME and MI with the right or left hand. Hemodynamic brain activity was measured with NIRS to monitor changes in oxygenated hemoglobin (oxy-Hb) concentration. Oxy-Hb in the somatosensory motor cortex (SMC) increased significantly only during contralateral ME and showed a significant interaction between task and hand. There was a main effect of hand in the left SMC. Although there were no significant main effects or interactions in the supplemental motor area (SMA) and premotor area (PMA), oxy-Hb increased substantially under all conditions. These results clarified the topographical localization by motor-related regional hemodynamic signal changes during ME and MI by using NIRS. PMID:26793118

  18. Monitoring Local Regional Hemodynamic Signal Changes during Motor Execution and Motor Imagery Using Near-Infrared Spectroscopy.

    PubMed

    Iso, Naoki; Moriuchi, Takefumi; Sagari, Akira; Kitajima, Eiji; Iso, Fumiko; Tanaka, Koji; Kikuchi, Yasuki; Tabira, Takayuki; Higashi, Toshio

    2015-01-01

    The aim of this study was to clarify the topographical localization of motor-related regional hemodynamic signal changes during motor execution (ME) and motor imagery (MI) by using near-infrared spectroscopy (NIRS), as this technique is more clinically expedient than established methods (e.g., fMRI). Twenty right-handed healthy subjects participated in this study. The experimental protocol was a blocked design consisting of 3 cycles of 20 s of task performance and 30 s of rest. The tapping sequence task was performed with their fingers under 4 conditions: ME and MI with the right or left hand. Hemodynamic brain activity was measured with NIRS to monitor changes in oxygenated hemoglobin (oxy-Hb) concentration. Oxy-Hb in the somatosensory motor cortex (SMC) increased significantly only during contralateral ME and showed a significant interaction between task and hand. There was a main effect of hand in the left SMC. Although there were no significant main effects or interactions in the supplemental motor area (SMA) and premotor area (PMA), oxy-Hb increased substantially under all conditions. These results clarified the topographical localization by motor-related regional hemodynamic signal changes during ME and MI by using NIRS.

  19. [Intracranial, cerebral perfusion pressure and systemic hemodynamic parameters during anesthesia induction in patients with traumatic brain compression].

    PubMed

    2012-01-01

    The study reports the dynamic of ICP, CPP and systemic hemodynamic rates during midazolam induction of anesthesia in patients with traumatic brain compression. Patients who need urgent surgery to eliminate brain compression of various degrees generally have intracranial hypertension. Midazolam administration decreases ICP by 22% from baseline under condition of stable hemodynamic and CPP. Depolarizing neuromuscular blocking agents' administration, mechanical ventilation and tracheal intubation lead to ICP elevation and CPP decreasing. The combination of midazolam and fentanil provides more reliable protection from hypertensive reactions.

  20. Ventilatory, hemodynamic, sympathetic nervous system, and vascular reactivity changes after recurrent nocturnal sustained hypoxia in humans.

    PubMed

    Gilmartin, Geoffrey S; Tamisier, Renaud; Curley, Matthew; Weiss, J Woodrow

    2008-08-01

    Recurrent and intermittent nocturnal hypoxia is characteristic of several diseases including chronic obstructive pulmonary disease, congestive heart failure, obesity-hypoventilation syndrome, and obstructive sleep apnea. The contribution of hypoxia to cardiovascular morbidity and mortality in these disease states is unclear, however. To investigate the impact of recurrent nocturnal hypoxia on hemodynamics, sympathetic activity, and vascular tone we evaluated 10 normal volunteers before and after 14 nights of nocturnal sustained hypoxia (mean oxygen saturation 84.2%, 9 h/night). Over the exposure, subjects exhibited ventilatory acclimatization to hypoxia as evidenced by an increase in resting ventilation (arterial Pco(2) 41.8 +/- 1.5 vs. 37.5 +/- 1.3 mmHg, mean +/- SD; P < 0.05) and in the isocapnic hypoxic ventilatory response (slope 0.49 +/- 0.1 vs. 1.32 +/- 0.2 l/min per 1% fall in saturation; P < 0.05). Subjects exhibited a significant increase in mean arterial pressure (86.7 +/- 6.1 vs. 90.5 +/- 7.6 mmHg; P < 0.001), muscle sympathetic nerve activity (20.8 +/- 2.8 vs. 28.2 +/- 3.3 bursts/min; P < 0.01), and forearm vascular resistance (39.6 +/- 3.5 vs. 47.5 +/- 4.8 mmHg.ml(-1).100 g tissue.min; P < 0.05). Forearm blood flow during acute isocapnic hypoxia was increased after exposure but during selective brachial intra-arterial vascular infusion of the alpha-blocker phentolamine it was unchanged after exposure. Finally, there was a decrease in reactive hyperemia to 15 min of forearm ischemia after the hypoxic exposure. Recurrent nocturnal hypoxia thus increases sympathetic activity and alters peripheral vascular tone. These changes may contribute to the increased cardiovascular and cerebrovascular risk associated with clinical diseases that are associated with chronic recurrent hypoxia.

  1. Spatial correlation of hemodynamic changes related to interictal epileptic discharges with electric and magnetic source imaging.

    PubMed

    Heers, Marcel; Hedrich, Tanguy; An, Dongmei; Dubeau, François; Gotman, Jean; Grova, Christophe; Kobayashi, Eliane

    2014-09-01

    Blood oxygenation level-dependent (BOLD) signal changes at the time of interictal epileptic discharges (IEDs) identify their associated vascular/hemodynamic responses. BOLD activations and deactivations can be found within the epileptogenic zone but also at a distance. Source imaging identifies electric (ESI) and magnetic (MSI) sources of IEDs, with the advantage of a higher temporal resolution. Therefore, the objective of our study was to evaluate the spatial concordance between ESI/MSI and BOLD responses for similar IEDs. Twenty-one patients with similar IEDs in simultaneous electroencephalogram/functional magnetic resonance imaging (EEG/fMRI) and in simultaneous EEG/magnetoencephalogram (MEG) recordings were studied. IEDs in EEG/fMRI acquisition were analyzed in an event-related paradigm within a general linear model (GLM). ESI/MSI of averaged IEDs was performed using the Maximum Entropy on the Mean. We assessed the spatial concordance between ESI/MSI and clusters of BOLD activations/deactivations with surface-based metrics. ESI/MSI were concordant with one BOLD cluster for 20/21 patients (concordance with activation: 14/21 patients, deactivation: 6/21 patients, no concordance: 1/21 patients; concordance with MSI only: 3/21, ESI only: 2/21). These BOLD clusters exhibited in 19/20 cases the most significant voxel. BOLD clusters that were spatially concordant with ESI/MSI were concordant with IEDs from invasive recordings in 8/11 patients (activations: 5/8, deactivations: 3/8). As the results of BOLD, ESI and MSI are often concordant, they reinforce our confidence in all of them. ESI and MSI confirm the most significant BOLD cluster within BOLD maps, emphasizing the importance of these clusters for the definition of the epileptic focus. Copyright © 2014 Wiley Periodicals, Inc.

  2. Monitoring of hemodynamic changes induced in the healthy breast through inspired gas stimuli with MR-guided diffuse optical imaging

    PubMed Central

    Carpenter, C. M.; Rakow-Penner, R.; Jiang, S.; Pogue, B. W.; Glover, G. H.; Paulsen, K. D.

    2010-01-01

    Purpose: The modulation of tissue hemodynamics has important clinical value in medicine for both tumor diagnosis and therapy. As an oncological tool, increasing tissue oxygenation via modulation of inspired gas has been proposed as a method to improve cancer therapy and determine radiation sensitivity. As a radiological tool, inducing changes in tissue total hemoglobin may provide a means to detect and characterize malignant tumors by providing information about tissue vascular function. The ability to change and measure tissue hemoglobin and oxygenation concentrations in the healthy breast during administration of three different types of modulated gas stimuli (oxygen∕carbogen, air∕carbogen, and air∕oxygen) was investigated. Methods: Subjects breathed combinations of gases which were modulated in time. MR-guided diffuse optical tomography measured total hemoglobin and oxygen saturation in the breast every 30 s during the 16 min breathing stimulus. Metrics of maximum correlation and phase lag were calculated by cross correlating the measured hemodynamics with the stimulus. These results were compared to an air∕air control to determine the hemodynamic changes compared to the baseline physiology. Results: This study demonstrated that a gas stimulus consisting of alternating oxygen∕carbogen induced the largest and most robust hemodynamic response in healthy breast parenchyma relative to the changes that occurred during the breathing of room air. This stimulus caused increases in total hemoglobin and oxygen saturation during the carbogen phase of gas inhalation, and decreases during the oxygen phase. These findings are consistent with the theory that oxygen acts as a vasoconstrictor, while carbogen acts as a vasodilator. However, difficulties in inducing a consistent change in tissue hemoglobin and oxygenation were observed because of variability in intersubject physiology, especially during the air∕oxygen or air∕carbogen modulated breathing protocols

  3. Hemodynamic Changes Following Endotracheal Intubation With Glidescope® Video-Laryngoscope in Patients With Untreated Hypertension

    PubMed Central

    Dashti, Majid; Amini, Shahram; Azarfarin, Rasoul; Totonchi, Ziae; Hatami, Maryam

    2014-01-01

    Background: Tracheal intubation can be associated with considerable hemodynamic changes, particularly in patients with uncontrolled hypertension. The GlideScope® video-laryngoscope (GVL) is a novel video laryngoscope that does not need direct exposure of the vocal cords, and it can also produce lower hemodynamic changes due to lower degrees of trauma and stimuli to the oropharynx than a Macintosh direct laryngoscope (MDL). Objectives: The aim of this clinical trial was to compare hemodynamic alterations following tracheal intubation with a GVL and MDL in patients with uncontrolled hypertension. Patients and Methods: Sixty patients who had uncontrolled hypertension and scheduled for elective surgery requiring tracheal intubation, were randomly assigned to receive intubated with either a GVL (n = 30) or a MDL (n = 30). Intubation time, heart rate, rate pressure product (RPP), and mean arterial blood pressure (MAP), were compared between the two groups at; baseline, following induction of anesthesia, after intubation, and at one minute intervals for 5 minutes. Results: A total of 59 patients finished the study. Intubation time was longer in the GVL group (9.80 ± 1.27 s) than in the MDL group (8.20 ± 1.17 s) (P < 0.05). MAP, pulse rate, and RPP were lower in the GVL than the MDL group after endotracheal intubation (P < 0.05). MAP, heart rate, and RPP returned to pre-intubation values at 3 and 4 minutes after intubation in the GVL and MDL groups, respectively (P < 0.05). Conclusions: Hemodynamic fluctuations in patients with uncontrolled hypertension after endotracheal intubation were lower with the GVL than the MDL technique. PMID:25478537

  4. Hemodynamic Changes Caused by Flow Diverters in Rabbit Aneurysm Models: Comparison of Virtual and Realistic FD Deployments Based on Micro-CT Reconstruction

    PubMed Central

    Fang, Yibin; Yu, Ying; Cheng, Jiyong; Wang, Shengzhang; Wang, Kuizhong; Liu, Jian-Min; Huang, Qinghai

    2013-01-01

    Adjusting hemodynamics via flow diverter (FD) implantation is emerging as a novel method of treating cerebral aneurysms. However, most previous FD-related hemodynamic studies were based on virtual FD deployment, which may produce different hemodynamic outcomes than realistic (in vivo) FD deployment. We compared hemodynamics between virtual FD and realistic FD deployments in rabbit aneurysm models using computational fluid dynamics (CFD) simulations. FDs were implanted for aneurysms in 14 rabbits. Vascular models based on rabbit-specific angiograms were reconstructed for CFD studies. Real FD configurations were reconstructed based on micro-CT scans after sacrifice, while virtual FD configurations were constructed with SolidWorks software. Hemodynamic parameters before and after FD deployment were analyzed. According to the metal coverage (MC) of implanted FDs calculated based on micro-CT reconstruction, 14 rabbits were divided into two groups (A, MC >35%; B, MC <35%). Normalized mean wall shear stress (WSS), relative residence time (RRT), inflow velocity, and inflow volume in Group A were significantly different (P<0.05) from virtual FD deployment, but pressure was not (P>0.05). The normalized mean WSS in Group A after realistic FD implantation was significantly lower than that of Group B. All parameters in Group B exhibited no significant difference between realistic and virtual FDs. This study confirmed MC-correlated differences in hemodynamic parameters between realistic and virtual FD deployment. PMID:23823503

  5. Hemodynamic Changes Caused by Flow Diverters in Rabbit Aneurysm Models: Comparison of Virtual and Realistic FD Deployments Based on Micro-CT Reconstruction.

    PubMed

    Xu, Jinyu; Deng, Benqiang; Fang, Yibin; Yu, Ying; Cheng, Jiyong; Wang, Shengzhang; Wang, Kuizhong; Liu, Jian-Min; Huang, Qinghai

    2013-01-01

    Adjusting hemodynamics via flow diverter (FD) implantation is emerging as a novel method of treating cerebral aneurysms. However, most previous FD-related hemodynamic studies were based on virtual FD deployment, which may produce different hemodynamic outcomes than realistic (in vivo) FD deployment. We compared hemodynamics between virtual FD and realistic FD deployments in rabbit aneurysm models using computational fluid dynamics (CFD) simulations. FDs were implanted for aneurysms in 14 rabbits. Vascular models based on rabbit-specific angiograms were reconstructed for CFD studies. Real FD configurations were reconstructed based on micro-CT scans after sacrifice, while virtual FD configurations were constructed with SolidWorks software. Hemodynamic parameters before and after FD deployment were analyzed. According to the metal coverage (MC) of implanted FDs calculated based on micro-CT reconstruction, 14 rabbits were divided into two groups (A, MC >35%; B, MC <35%). Normalized mean wall shear stress (WSS), relative residence time (RRT), inflow velocity, and inflow volume in Group A were significantly different (P<0.05) from virtual FD deployment, but pressure was not (P>0.05). The normalized mean WSS in Group A after realistic FD implantation was significantly lower than that of Group B. All parameters in Group B exhibited no significant difference between realistic and virtual FDs. This study confirmed MC-correlated differences in hemodynamic parameters between realistic and virtual FD deployment.

  6. Quantitative assessment of cerebral hemodynamic parameters by QUASAR arterial spin labeling in Alzheimer's disease and cognitively normal Elderly adults at 3-tesla.

    PubMed

    Mak, Henry K F; Chan, Queenie; Zhang, Zhipeng; Petersen, Esben T; Qiu, Deqiang; Zhang, Linda; Yau, Kelvin K W; Chu, Leung-Wing; Golay, Xavier

    2012-01-01

    QUASAR arterial spin labeling (ASL) was used to investigate the role of vascular impairment in Alzheimer's disease (AD). We hypothesized that the hemodynamic parameters monitoring cerebrovascular integrity, i.e., cerebral blood flow (CBF), arterial blood volume (aBV), and arterial transit time (aTT), would be affected. 13 AD patients and 15 healthy control (HC) subjects underwent 3T MRI scanning. Two separate blood flow acquisitions were obtained with 1 slice overlap for whole brain coverage. CBF, aBV, and aTT maps were calculated using in-house software. Preprocessing and statistical analyses were performed on SPM5. Region-of-interest (ROI) studies of ten selected cerebral regions were also conducted. There were significant differences in mini mental status exam (MMSE) (AD: 16.3 ± 4.55, HC: 28.5 ± 2.00) and Alzheimer's disease assessment scale-cognitive subscale (ADAS-cog) scores (AD: 25.25 ± 9.64, HC: 5.51 ± 2.62) between the 2 groups (p < 0.001) but none in age (p = 0.068). CBF decreased significantly (p < 0.01) in AD compared to controls in the right middle cingulate, left cuneus, left inferior and middle frontal, right superior frontal, left inferior parietal, and right supramarginal gyri. ROI studies confirmed significant hemodynamic impairments in AD compared to HC (p < 0.05): CBF in middle and posterior cingulate, aBV in left superior temporal, right inferior parietal, and posterior cingulate, and aTT in left inferior frontal and middle cingulate gyri. CBF correlated positively while aTT correlated negatively to MMSE, and vice versa for ADAS-cog. Using QUASAR ASL, we found patterns of regional hemodynamic impairment typical of moderate AD, suggesting underlying vascular abnormality. As potential biomarkers, these hemodynamic parameters could differentiate patients from volunteers, and possibly indicate the conversion from healthy aging to mild cognitive impairment to AD.

  7. The Potential of Computational Fluid Dynamics Simulation on Serial Monitoring of Hemodynamic Change in Type B Aortic Dissection.

    PubMed

    Yu, Simon C H; Liu, Wen; Wong, Randolph H L; Underwood, Malcolm; Wang, Defeng

    2016-08-01

    We aimed to assess the potential of computational fluid dynamics simulation (CFD) in detecting changes in pressure and flow velocity in response to morphological changes in type B aortic dissection. Pressure and velocity in four morphological models of type B aortic dissection before and after closure of the entry tear were calculated with CFD and analyzed for changes among the different scenarios. The control model (Model 1) was patient specific and built from the DICOM data of CTA, which bore one entry tear and three re-entry tears. Models 2-4 were modifications of Model 1, with two re-entry tears less in Model 2, one re-entry tear more in Model 3, and a larger entry tear in Model 4. The pressure and velocity pertaining to each of the morphological models were unique. Changes in pressure and velocity findings were accountable by the changes in morphological features of the different models. There was no blood flow in the false lumen across the entry tear after its closure, the blood flow direction across the re-entry tears was reversed after closure of the entry tear. CFD simulation is probably useful to detect hemodynamic changes in the true and false lumens of type B aortic dissection in response to morphological changes, it may potentially be developed into a non-invasive and patient-specific tool for serial monitoring of hemodynamic changes of type B aortic dissection before and after treatment.

  8. The Relationship between Serum Oxalic Acid, Central Hemodynamic Parameters and Colonization by Oxalobacter formigenes in Hemodialysis Patients

    PubMed Central

    Gulhan, Baris; Turkmen, Kultigin; Aydin, Merve; Gunay, Murat; Cıkman, Aytekin; Kara, Murat

    2015-01-01

    Background/Objective Elevated pulse wave velocity (PWV) and central aortic blood pressures are independent predictors of increased cardiovascular morbidity and mortality in hemodialysis (HD) patients. Oxalic acid is a uremic retention molecule that is extensively studied in the pathogenesis of calcium oxalate stones. Oxalobacter formigenes, a member of the colon microbiota, has important roles in oxalate homeostasis. Data regarding the colonization by and the exact role of O. formigenes in the pathogenesis of oxalic acid metabolism in HD patients are scant. Hence, we aimed to determine the relationship between fecal O. formigenes colonization, serum oxalic acid and hemodynamic parameters in HD patients with regard to the colo-reno-cardiac axis. Methods Fifty HD patients were enrolled in this study. PWV and central aortic systolic (cASBP) and diastolic blood pressures (cADBP) were measured with a Mobil-O-Graph (I.E.M. GmbH, Stolberg, Germany). Serum oxalic acid levels were assessed by ELISA, and fecal O. formigenes DNA levels were isolated and measured by real-time PCR. Results Isolation of fecal O. formigenes was found in only 2 HD patients. One of them had 113,609 copies/ml, the other one had 1,056 copies/ml. Serum oxalic acid levels were found to be positively correlated with PWV (r = 0.29, p = 0.03), cASBP (r = 0.33, p = 0.001) and cADBP (r = 0.42, p = 0.002) and negatively correlated with LDL (r = −0.30, p = 0.03). In multivariate linear regression analysis, PWV was independently predicted by oxalic acid, glucose and triglyceride. Conclusions This is the first study that demonstrates the absence of O. formigenes as well as a relation between serum oxalic acid and cASBP, cADBP and PWV in HD patients. Replacement of O. formigenes with pre- and probiotics might decrease serum oxalic acid levels and improve cardiovascular outcomes in HD patients. PMID:26195968

  9. Bladder distension: An unusual cause of reflux of blood and hemodynamic changes (autonomic dysreflexia) during endovascular coiling

    PubMed Central

    Sharma, DP; Singh, Daljit; Ganjoo, P; Tandon, M

    2011-01-01

    Autonomic dysreflexia due to distended bladder is well known. Reflux of blood during endovascular procedure is also a common observation. It happens due to difference in pressure gradient between arterial pressure and that of infusing solution. Generally it happens when the infusion bottle is empty or the pressure in infusion bottles fall. We present an uncommon situation where distended bladder mechanically resulted in reflux of blood into endovascular catheters as well as alteration in hemodynamic parameters. Both settled once the bladder was empty. PMID:21897687

  10. Impact of heat on metabolic and hemodynamic changes in transcranial infrared laser stimulation measured by broadband near-infrared spectroscopy.

    PubMed

    Wang, Xinlong; Reddy, Divya D; Nalawade, Sahil S; Pal, Suvra; Gonzalez-Lima, F; Liu, Hanli

    2018-01-01

    Transcranial infrared laser stimulation (TILS) has shown effectiveness in improving human cognition and was investigated using broadband near-infrared spectroscopy (bb-NIRS) in our previous study, but the effect of laser heating on the actual bb-NIRS measurements was not investigated. To address this potential confounding factor, 11 human participants were studied. First, we measured time-dependent temperature increases on forehead skin using clinical-grade thermometers following the TILS experimental protocol used in our previous study. Second, a subject-averaged, time-dependent temperature alteration curve was obtained, based on which a heat generator was controlled to induce the same temperature increase at the same forehead location that TILS was delivered on each participant. Third, the same bb-NIRS system was employed to monitor hemodynamic and metabolic changes of forehead tissue near the thermal stimulation site before, during, and after the heat stimulation. The results showed that cytochrome-c-oxidase of forehead tissue was not significantly modified by this heat stimulation. Significant differences in oxyhemoglobin, total hemoglobin, and differential hemoglobin concentrations were observed during the heat stimulation period versus the laser stimulation. The study demonstrated a transient hemodynamic effect of heat-based stimulation distinct to that of TILS. We concluded that the observed effects of TILS on cerebral hemodynamics and metabolism are not induced by heating the skin.

  11. In vivo hemodynamic and electrocardiographic changes following Crataegus aronia syn. Azarolus L administration to normotensive Wistar rats.

    PubMed

    Shatoor, Abdullah S

    2013-02-01

    To evaluate the effects of the whole plant aqueous extract of Crataegus aronia (C. aronia) syn. Azarolus (L) on the hemodynamic and electrocardiographic intervals in albino rats. This study was carried out in 2 stages at the Research Laboratory, Physiology Department, Medical College of King Khalid University, Abha, Kingdom of Saudi Arabia between February and June 2012. First, the effects of C. aronia syn. Azarolus (L) on the hemodynamics and electrocardiograph in 54 Wistar male rats were assessed, then the mechanisms underlying the hemodynamic and electrocardiographic changes observed in the first stage were evaluated in 48 rats of the same species. The C. aronia administered at escalating doses (0.05-20 microgram/kg) produced a dose-time-dependent decrease in heart rate (HR) and mean arterial pressure (MAP). Higher doses (15 and 20 microgram/kg) produced the most significant reduction in both HR and MAP, and induced sinus node suppression and progressive atrio-ventricular blockade. The underlying mechanism of the induced bradyarrhythmia appeared to be due to the direct stimulation of the muscarinic receptor M2 and possible blockade of beta-receptors, while the hypotension was caused by enhanced nitric oxide release. No significant alterations in the electrocardiogram (ECG) components were observed. The administration of the C. aronia syn. Azarolus extract induced bradyarrhythmia and hypotension, without alteration in the ECG components.

  12. Change of coagulation parameters after double plateletpheresis.

    PubMed

    Yilmaz, Mustafa; Dikmen, Tamer; Sonmez, Mehmet; Akdogan, Elif; Durmus, Ahmet; Omay, Serdar Bedii; Ovali, Ercument

    2007-10-01

    In the previous studies, some authors reported that automated apheresis leads to a hypercoagulable state. We tried to find out changes in coagulation parameters after double plateletpheresis in this study. Forty-five donors were recruited to the study, and coagulation parameters were assessed before and after double plateletpheresis. After double plateletpheresis, fibrinogen, factor V, factor VIII and factor IX were decreased compared with the values before apheresis. Although serum levels of this coagulation parameters are decreasing, they are still in the normal limits. Therefore, we suggest that double plateletpheresis is a safe procedure for healthy volunteers taking into account these coagulation parameters.

  13. Arterial spin labeling MRI is able to detect early hemodynamic changes in diabetic nephropathy.

    PubMed

    Mora-Gutiérrez, José María; Garcia-Fernandez, Nuria; Slon Roblero, M Fernanda; Páramo, Jose A; Escalada, F Javier; Wang, Danny Jj; Benito, Alberto; Fernández-Seara, María A

    2017-04-06

    To investigate whether arterial spin labeling (ASL) MRI could detect renal hemodynamic impairment in diabetes mellitus (DM) along different stages of chronic kidney disease (CKD). Three Tesla (3T) ASL-MRI was performed to evaluate renal blood flow (RBF) in 91 subjects (46 healthy volunteers and 45 type 2 diabetic patients). Patients were classified according to their estimated glomerular filtration rate (eGFR) as group I (eGFR > 60 mL/min/1.73 m(2) ), group II (60 ≥ eGFR>30 mL/min/1.73 m(2) ), or group III (eGFR ≤ 30 mL/min/1.73 m(2) ), to determine differences depending on renal function. Studies were performed at 3T using a 12-channel flexible body array combined with the spine array coil as receiver. A 28% reduction in cortical RBF was seen in diabetics in comparison with healthy controls (185.79 [54.60] versus 258.83 [37.96] mL/min/100 g, P < 3 × 10(-6) ). Differences were also seen between controls and diabetic patients despite normal eGFR and absence of overt albuminuria (RBF [mL/min/100 g]: controls=258.83 [37.96], group I=208.89 [58.83], P = 0.0018; eGFR [mL/min/1.73 m(2) ]: controls = 95.50 [12.60], group I = 82.00 [20.76], P > 0.05; albumin-creatinine ratio [mg/g]: controls = 3.50 [4.45], group I = 17.50 [21.20], P > 0.05). A marked decrease in RBF was noted a long with progression of diabetic nephropathy (DN) through the five stages of CKD (χ(2)  = 43.58; P = 1.85 × 10(-9) ). Strong correlation (r = 0.62; P = 4 × 10(-10) ) was obtained between RBF and GFR estimated by cystatin C. ASL-MRI is able to quantify early renal perfusion impairment in DM, as well as changes according to different CKD stages of DN. In addition, we demonstrated a correlation of RBF quantified by ASL and GFR estimated by cystatin C. 3 J. Magn. Reson. Imaging 2017. © 2017 International Society for Magnetic Resonance in Medicine.

  14. Serial changes of hemodynamic performance with Medtronic Hall valve in aortic position.

    PubMed

    Cho, Yang Hyun; Jeong, Dong Seop; Park, Pyo Won; Park, Kay-Hyun; Sung, Kiick; Kim, Wook Sung; Lee, Young Tak

    2011-02-01

    The aim of this study was to evaluate the long-term hemodynamic performance of the Medtronic Hall valve by analyzing serial changes in echocardiographic outcomes in aortic position. One hundred seventeen patients who underwent aortic valve replacement (AVR) using the Medtronic Hall valve between August 1997 and January 2004 were retrospectively studied. Fifty-five patients underwent isolated AVR (AVR group), and 62 patients underwent AVR and mitral valve replacement (double valve replacement group). Mean age was 51.2 ± 10.4 years (range, 26 to 67 years), and mean follow-up duration was 93.7 ± 25.6 months (913.6 patient-years; range, 17 to 140 months). Serial echocardiographic data were analyzed. Overall mortality was 12.8% (15 of 117), but no early mortality occurred. A greater than 15 mm Hg increment of aortic transprosthetic mean pressure gradient at last follow-up occurred in 13 patients (11.1%). Redo AVR was performed in 7 patients, 6 of whom had subaortic pannus ingrowths. Group cumulative survival rates at 10 years were similar (90.4%, AVR group versus 88.4%, double valve replacement group; p = 0.580), but the AVR group showed better adverse cardiac event-free survival at 10 years (80.1% versus 53.8%; p = 0.025). Multivariate analysis showed that double valve replacement and a small-sized valve (20 mm) significantly predicted the increment of aortic transprosthetic mean pressure gradient at last follow up greater than 15 mm Hg (p = 0.013; odds ratio, 13.9; p = 0.019; odds ratio, 4.2, respectively). The transprosthetic mean pressure gradient of the Medtronic Hall valve in the aortic position frequently increased as a function of time, and this increase was more common in patients who had undergone double valve replacement, especially in those implanted with a small valve. Copyright © 2011 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

  15. [Hemodynamics study of cardiovascular system in vitro simulation].

    PubMed

    Li, Hong; Qian, Kunxi

    2006-08-01

    In order to study the cardiovascular hemodynamic characteristics and evaluate the blood pump, we made a series of cardiovascular simulation devices which could reflect the hemodynamics of blood circulation system by the elastic chamber model, and tested the relations between cardiovascular hemodynamic parameters (such as systole pressure, diastole pressure, average pressure, pulsative pressure, flow rate) and ventricular afterload (peripheral resistance and vascular compliance) as well as cardiac output, diastolic period, systole period and preload. The effect of the parameters on the arterial pressure and flow rate was estimated when any one of the parameters was changed. The result of simulating experiment was coincided with that deduced from mathematical model and physiologic condition. Therefore the series of cardiovascular simulation devices can reflect the hemodynamics of blood circulation.

  16. The cardioprotective effect of vanillic acid on hemodynamic parameters, malondialdehyde, and infarct size in ischemia-reperfusion isolated rat heart exposed to PM10

    PubMed Central

    Radmanesh, Esmat; Dianat, Mahin; Badavi, Mohammad; Goudarzi, Gholamreza; Mard, Seyyed Ali

    2017-01-01

    Objective(s): Particulate matter (PM) exposure can promote cardiac ischemia and myocardial damage. The effects of PM10 on hemodynamic parameters, lipid peroxidation, and infarct size induced by ischemia-reperfusion injury and the protective effects of vanillic acid (VA) in isolated rat heart were investigated. Materials and Methods: Eighty male Wistar rats (250–300 g) were divided into 8 groups (n=10): Control, Sham, VAc, VA, PMa (0.5 mg/kg PM, intratracheal instillation), PMb (2.5 mg/kg PM, intratracheal instillation), PMc (5 mg/kg PM, intratracheal instillation), and PMc + VA (5 mg/kg PM, intratracheal instillation; and 10 mg/kg vanillic acid, gavage for 10 days). PM10 was instilled into the trachea in two stages, within 48 hr. After isolating the hearts and transfer to a Langendorff apparatus, hearts were subjected to 30 min ischemia and 60 min reperfusion. Hemodynamic parameters (±dp/dt, LVSP, LVDP, and RPP), production of lipid peroxidation (MDA), and infarct size were assessed. Results: A significant decrease in ±dp/dt, LVSP, LVDP and RPP occurred in PM groups. A significant increase in MDA and myocardial infarct size occurred in PM groups. A significant increase in LVDP, LVSP, ±dp/dt, RPP and decrease in infarct size, MDA, and myocardial dysfunction was observed in groups that received vanillic acid after ischemia–reperfusion. Conclusion: It was demonstrated that PM10 increases MDA, as well as the percentage of cardiac infarct size, and has negative effects on hemodynamic parameters. This study suggests that vanillic acid may serve as an adjunctive treatment in delaying the progression of ischemic heart disease. PMID:28852440

  17. The Effect of Sorafenib, Tadalafil and Macitentan Treatments on Thyroxin-Induced Hemodynamic Changes and Cardiac Abnormalities

    PubMed Central

    Saad, Nancy S.; Floyd, Kyle; Ahmed, Amany A. E.; Mohler, Peter J.

    2016-01-01

    Multikinase inhibitors (e.g. Sorafenib), phosphodiesterase-5 inhibitors (e.g. Tadalafil), and endothelin-1 receptor blockers (e.g. Macitentan) exert influential protection in a variety of animal models of cardiomyopathy; however, their effects on thyroxin-induced cardiomyopathy have never been investigated. The goal of the present study was to assess the functional impact of these drugs on thyroxin-induced hemodynamic changes, cardiac hypertrophy and associated altered responses of the contractile myocardium both in-vivo at the whole heart level and ex-vivo at the cardiac tissue level. Control and thyroxin (500 μg/kg/day)-treated mice with or without 2-week treatments of sorafenib (10 mg/kg/day; I.P), tadalafil (1 mg/kg/day; I.P or 4 mg/kg/day; oral), macitentan (30 and 100 mg/kg/day; oral), and their vehicles were studied. Blood pressure, echocardiography and electrocardiogram were non-invasively evaluated, followed by ex-vivo assessments of isolated multicellular cardiac preparations. Thyroxin increased blood pressure, resulted in cardiac hypertrophy and left ventricular dysfunction in-vivo. Also, it caused contractile abnormalities in right ventricular papillary muscles ex-vivo. None of the drug treatments were able to significantly attenuate theses hemodynamic changes or cardiac abnormalities in thyroxin-treated mice. We show here for the first time that multikinase (raf1/b, VEGFR, PDGFR), phosphodiesterase-5, and endothelin-1 pathways have no major role in thyroxin-induced hemodynamic changes and cardiac abnormalities. In particular, our data show that the involvement of endothelin-1 pathway in thyroxine-induced cardiac hypertrophy/dysfunction seems to be model-dependent and should be carefully interpreted. PMID:27082116

  18. Investigation of cerebral hemodynamic changes during repeated sit-stand maneuver using functional near-infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Niu, Haijing; Li, Lin; Bhave, Gauri S.; Lin, Zi-jing; Tian, Fenghua; Khosrow, Behbehani; Zhang, Rong; Liu, Hanli

    2011-03-01

    The goal for this study is to examine cerebral autoregulation in response to a repeated sit-stand maneuver using both diffuse functional Near Infrared spectroscopy (fNIRS) and Transcranial Doppler sonography (TCD). While fNIRS can provide transient changes in hemodynamic response to such a physical action, TCD is a noninvasive transcranial method to detect the flow velocities in the basal or middle cerebral arteries (MCA). The initial phase of this study was to measure fNIRS signals from the forehead of subjects during the repeated sit-stand protocol and to understand the corresponding meaning of the detected signals. Also, we acquired preliminary data from simultaneous measurements of fNIRS and TCD during the sit-stand protocol so as to explore the technical difficulty of such an approach. Specifically, ten healthy adult subjects were enrolled to perform the planned protocol, and the fNIRS array probes with 4 sources and 10 detectors were placed on the subject's forehead to detect hemodynamic signal changes from the prefrontal cortex. The fNIRS results show that the oscillations of hemoglobin concentration were spatially global and temporally dynamic across the entire region of subject's forehead. The oscillation patterns in both hemoglobin concentrations and blood flow velocity seemed to follow one another; changes in oxy-hemoglobin concentration were much larger than those in deoxyhemoglobin concentration. These preliminary findings provide us with evidence that fNIRS is an appropriate means readily for studying cerebral hemodynamics and autoregulation during sit-stand maneuvers.

  19. Changes in hemodynamic signals accompanying motor imagery and motor execution of swallowing: a near-infrared spectroscopy study.

    PubMed

    Kober, S E; Wood, G

    2014-06-01

    In the present study we investigated hemodynamic changes in the brain in response to motor execution (ME) and motor imagery (MI) of swallowing using near-infrared spectroscopy (NIRS). Previous studies provide evidence that ME and MI of limb movements lead to comparable brain activation patterns indicating the potential value of MI for motor rehabilitation. In this context, identifying brain correlates of MI of swallowing may be potentially useful for the treatment of dysphagia. Fourteen healthy participants actively swallowed water (ME) and mentally imagined to swallow water (MI) in a randomized order while changes in concentration of oxygenated hemoglobin (oxy-Hb) and deoxygenated hemoglobin (deoxy-Hb) were assessed. MI and ME led to the strongest NIRS signal changes in the inferior frontal gyrus. During and after ME, oxy-Hb significantly increased, with a maximum peak around 15s after task onset. In contrast, oxy-Hb decreased during MI compared to a rest period probably because of motor inhibition mechanisms. Changes in deoxy-Hb were largely comparable between MI and ME, especially when participants used a kinesthetic motor imagery strategy during MI compared to no specific strategy. Hence, the present study provides new evidence concerning timing and topographical distribution of the hemodynamic response during ME and MI of swallowing. Copyright © 2014 Elsevier Inc. All rights reserved.

  20. A Two-Part Approach to Examine the Effects of Theacrine (TeaCrine®) Supplementation on Oxygen Consumption, Hemodynamic Responses, and Subjective Measures of Cognitive and Psychometric Parameters.

    PubMed

    Ziegenfuss, Tim N; Habowski, Scott M; Sandrock, Jennifer E; Kedia, A William; Kerksick, Chad M; Lopez, Hector L

    2016-05-10

    Theacrine (1,3,7,9-tetramethyluric acid) is a naturally occurring purine alkaloid, present in Camellia assamica variety kucha tea. Using a two-part approach in humans, the impact of theacrine (TeaCrine®, TC) was used to examine subjective dose-response, daily changes in cognitive and psychometric parameters, and changes in gas exchange and vital signs. All indicators were chosen to better ascertain the previously reported animal and human outcomes involving theacrine administration. Part 1 was a randomized, open-label, dose-response investigation in nine healthy participants whereby three participants ingested 400 mg TC per day and six participants ingested 200 mg/day. Participants recorded subjective changes in cognitive, psychometric, and exercise attributes using 150-mm anchored visual analog scale (VAS) before, and 1, 4, and 6 hours after ingestion every day for 7 consecutive days. Part 2 was a randomized, double-blind, placebo-controlled, crossover investigation in 15 healthy subjects in which all participants ingested a single 200 mg dose of TC or Placebo (PLA). Anchored VAS questionnaires were used to detect subjective changes in various aspects of physical and mental energy along with changes in gas exchange and hemodynamic parameters before, and 1, 2, and 3 hours after acute ingestion. Energy, focus, and concentration increased from baseline values in both doses with no dose-response effect. VAS responses in the 200 mg for willingness to exercise, anxiety, motivation to train and libido increased across the measurement period while no such change was seen with the 400 mg dose. After consuming a single 200 mg dose, significant group × time interaction effects were seen for energy, fatigue, and concentration. No changes in resting heart rate, gas exchange, systemic hemodynamics or side effect profiles were noted.

  1. The effect of combined conventional and modified ultrafiltration on mechanical ventilation and hemodynamic changes in congenital heart surgery

    PubMed Central

    Ziyaeifard, Mohsen; Alizadehasl, Azin; Aghdaii, Nahid; Rahimzadeh, Poupak; Masoumi, Gholamreza; Golzari, Samad EJ; Fatahi, Mostafa; Gorjipur, Farhad

    2016-01-01

    Background: Cardiopulmonary bypass is associated with increased fluid accumulation around the heart which influences pulmonary and cardiac diastolic function. The aim of this study was to compare the effects of modified ultrafiltration (MUF) versus conventional ultrafiltration (CUF) on duration of mechanical ventilation and hemodynamic status in children undergoing congenital heart surgery. Materials and Methods: A randomized clinical trial was conducted on 46 pediatric patients undergoing cardiopulmonary bypass throughout their congenital heart surgery. Arteriovenous MUF plus CUF was performed in 23 patients (intervention group) and sole CUF was performed for other 23 patients (control group). In MUF group, arterial cannula was linked to the filter inlet through the arterial line, and for 10 min, 10 ml/kg/min of blood was filtered and returned via cardioplegia line to the right atrium. Different parameters including hemodynamic variables, length of mechanical ventilation, Intensive Care Unit (ICU) stay, and inotrope requirement were compared between the two groups. Results: At immediate post-MUF phase, there was a statistically significant increase in the mean arterial pressure, systolic blood pressure, and diastolic blood pressure (P < 0.05) only in the study group. Furthermore, there was a significant difference in time of mechanical ventilation (P = 0.004) and ICU stay (P = 0.007) between the two groups. Inotropes including milrinone (P = 0.04), epinephrine (P = 0.001), and dobutamine (P = 0.002) were used significantly less frequently for patients in the intervention than the control group. Conclusion: Administration of MUF following surgery improves hemodynamic status of patients and also significantly decreases the duration of mechanical ventilation and inotrope requirement within 48 h after surgery. PMID:28255321

  2. Novel Use of a Noninvasive Hemodynamic Monitor in a Personalized, Active Learning Simulation

    ERIC Educational Resources Information Center

    Zoller, Jonathan K.; He, Jianghua; Ballew, Angela T.; Orr, Walter N.; Flynn, Brigid C.

    2017-01-01

    The present study furthered the concept of simulation-based medical education by applying a personalized active learning component. We tested this novel approach utilizing a noninvasive hemodynamic monitor with the capability to measure and display in real time numerous hemodynamic parameters in the exercising participant. Changes in medical…

  3. The relationship between weight, height and body mass index with hemodynamic parameters is not same in patients with and without chronic kidney disease.

    PubMed

    Afsar, Baris; Elsurer, Rengin; Soypacaci, Zeki; Kanbay, Mehmet

    2016-02-01

    Although anthropometric measurements are related with clinical outcomes; these relationships are not universal and differ in some disease states such as in chronic kidney disease (CKD). The current study was aimed to analyze the relationship between height, weight and BMI with hemodynamic and arterial stiffness parameters both in normal and CKD patients separately. This cross-sectional study included 381 patients with (N 226) and without CKD (N 155) with hypertension. Routine laboratory and 24-h urine collection were performed. Augmentation index (Aix) which is the ratio of augmentation pressure to pulse pressure was calculated from the blood pressure waveform after adjusted heart rate at 75 [Aix@75 (%)]. Pulse wave velocity (PWV) is a simple measure of the time taken by the pressure wave to travel over a specific distance. Both [Aix@75 (%)] and PWV which are measures of arterial stiffness were measured by validated oscillometric methods using mobil-O-Graph device. In patients without CKD, height is inversely correlated with [Aix@75 (%)]. Additionally, weight and BMI were positively associated with PWV in multivariate analysis. However, in patients with CKD, weight and BMI were inversely and independently related with PWV. In CKD patients, as weight and BMI increased stiffness parameters such as Aix@75 (%) and PWV decreased. While BMI and weight are positively associated with arterial stiffness in normal patients, this association is negative in patients with CKD. In conclusion, height, weight and BMI relationship with hemodynamic and arterial stiffness parameters differs in patients with and without CKD.

  4. Brachial Pressure Control Fails to Account for Most Distending Pressure-Independent, Age-Related Aortic Hemodynamic Changes in Adults.

    PubMed

    Hodson, Bryan; Norton, Gavin R; Booysen, Hendrik L; Sibiya, Moekanyi J; Raymond, Andrew; Maseko, Muzi J; Majane, Olebogeng H I; Libhaber, Elena; Sareli, Pinhas; Woodiwiss, Angela J

    2016-05-01

    Although several characteristics of aortic function, which are largely determined by age, predict outcomes beyond brachial blood pressure (BP), the extent to which brachial BP control accounts for age-related variations in aortic function is uncertain. We aimed to determine the extent to which brachial BP control in the general population (systolic/diastolic BP < 140/90 mm Hg) accounts for age-related aortic hemodynamic changes across the adult lifespan. Central aortic pulse pressure (PPc), backward wave pressure (Pb), pulse wave velocity (PWV), and PP amplification (PPamp) (applanation tonometry and SphygmoCor software) were determined in 1,185 participants from a community sample (age >16 years; 36.4% uncontrolled BP). With adjustments for distending pressure (mean arterial pressure, MAP), no increases in PPc, Pb, or PWV and decreases in PPamp were noted in those with an uncontrolled brachial BP younger than 50 years. In those older than 50 years with an uncontrolled brachial BP, MAP-adjusted aortic hemodynamic variables were only modestly different to those with a controlled brachial BP (PPc, 46±14 vs. 42±15 mm Hg, P < 0.02, Pb, 23±8 vs. 21±8 mm Hg, PWV, 8.42±3.21 vs. 8.19±3.37 m/second, PPamp, 1.21±0.17 vs. 1.21±0.14). Nonetheless, with adjustments for MAP, marked age-related increases in PPc, Pb, and PWV and decreases in PPamp were noted in those with uncontrolled and controlled brachial BP across the adult lifespan (P < 0.0001). Brachial BP control in the general population fails to account for most distending pressure-independent, age-related changes in aortic hemodynamics across the adult lifespan. © American Journal of Hypertension, Ltd 2015. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  5. Comparison of Remifentanil and Fentanyl Regarding Hemodynamic Changes Due to Endotracheal Intubation in Preeclamptic Parturient Candidate for Cesarean Delivery

    PubMed Central

    Pournajafian, Alireza; Rokhtabnak, Faranak; Kholdbarin, Alireza; Ghodrati, Mohammadreza; Ghavam, Siamak

    2012-01-01

    Background Intravenous opioids are administered to prevent and control hemodynamic changes due to endotracheal intubation. Except for special cases such as preeclampsia, these drugs are not recommended for parturants candidate for cesarean section because of the respiratory depression caused in the newborn. Objectives According to rapid metabolism of remifentanil, the current study aimed to compare hemodynamic changes in preeclamptic parturants who received remifentanil and fentanyl for cesarean section under general anesthesia. Patients and Methods This single blind randomized clinical trial was performed on preeclamptic pregnant women candidate for cesarean section under general anesthesia. They were divided into two groups. In the first group 0.05 μg/kg/min remifentanil was infused for 3 minutes before induction of anesthesia and in the second group 1ml (50 μg) fentanyl was injected before induction. Heart rate (HR), systolic blood pressure (SBP) and diastolic blood pressure (DBP) before and after intubation and also Apgar index were measured and compared between the two groups. Results All hemodynamic variables increased after intubation in the fentanyl group (pSBP = 0.146, pDBP = 0.019, pHR < 0.001). Additionally, decrease in SBP (P = 0.018) and DBP (P = 0.955) and mild increase in HR (P = 0.069) after intubation in the remifentanil group was observed. No significant difference was found between Apgar indexes of the two groups (P = 0.771). Conclusions It can be postulated that remifentanil can be used in partituents candidate for cesarean delivery under general anesthesia to prevent severe increase in blood pressure and heart rate during tracheal intubation without adverse effects on newborn. PMID:24223345

  6. Comparison of remifentanil and fentanyl regarding hemodynamic changes due to endotracheal intubation in preeclamptic parturient candidate for cesarean delivery.

    PubMed

    Pournajafian, Alireza; Rokhtabnak, Faranak; Kholdbarin, Alireza; Ghodrati, Mohammadreza; Ghavam, Siamak

    2012-01-01

    Intravenous opioids are administered to prevent and control hemodynamic changes due to endotracheal intubation. Except for special cases such as preeclampsia, these drugs are not recommended for parturants candidate for cesarean section because of the respiratory depression caused in the newborn. According to rapid metabolism of remifentanil, the current study aimed to compare hemodynamic changes in preeclamptic parturants who received remifentanil and fentanyl for cesarean section under general anesthesia. This single blind randomized clinical trial was performed on preeclamptic pregnant women candidate for cesarean section under general anesthesia. They were divided into two groups. In the first group 0.05 μg/kg/min remifentanil was infused for 3 minutes before induction of anesthesia and in the second group 1ml (50 μg) fentanyl was injected before induction. Heart rate (HR), systolic blood pressure (SBP) and diastolic blood pressure (DBP) before and after intubation and also Apgar index were measured and compared between the two groups. All hemodynamic variables increased after intubation in the fentanyl group (pSBP = 0.146, pDBP = 0.019, pHR < 0.001). Additionally, decrease in SBP (P = 0.018) and DBP (P = 0.955) and mild increase in HR (P = 0.069) after intubation in the remifentanil group was observed. No significant difference was found between Apgar indexes of the two groups (P = 0.771). It can be postulated that remifentanil can be used in partituents candidate for cesarean delivery under general anesthesia to prevent severe increase in blood pressure and heart rate during tracheal intubation without adverse effects on newborn.

  7. Changes in peripheral vascular and cardiac sympathetic activity before and after coronary artery bypass surgery: interrelationships with hemodynamic alterations.

    PubMed

    Kim, Y D; Jones, M; Hanowell, S T; Koch, J P; Lees, D E; Weise, V; Kopin, I J

    1981-12-01

    The plasma catecholamine levels obtained simultaneously from radial artery (A), pulmonary artery (MV), brachial vein (PV), and coronary sinus (CS) were measured concurrent with hemodynamic determinations during coronary artery bypass graft (CABG) operations. Arterial catecholamine levels decreased after induction of anesthesia and increased after sternotomy; changes in veno-arterial norepinephrine (NE) differences ([PV-A]ne, [MV-A]ne, and [CS-A]ne) were of the same magnitude and direction, suggesting that NE release from various organs was of the same extent. After operation, arterial NE increased further, but the veno-arterial NE differences were in striking contrast; [PV-A]ne became markedly positive, whereas [CS-A]ne became markedly negative, indicating that NE release from extremity peripheral vasculature increased markedly while cardiac NE release decreased. These differential changes in regional sympathetic activity appear to be related to postoperative hypertension (HT) and low cardiac output (CO). There were close relationships of changes in [MV-A]ne to mean arterial pressure (r = 0.78, p less than 0.001) and systemic vascular resistance (r = 0.62, p less than 0.010, suggesting that the sympathetic nervous system plays an important role in CABG perioperative hemodynamic alterations.

  8. Changing Throwing Pattern: Instruction and Control Parameter

    ERIC Educational Resources Information Center

    Southard, Dan

    2006-01-01

    The purpose of this study was to determine the effects of instruction and scaling up a control parameter (velocity of throw) on changes in throwing pattern. Sixty adult female throwers (ages 20-26 years) were randomly placed into one of four practice conditions: (a) scale up on velocity with no instruction, (b) maintain constant velocity with no…

  9. Changing Throwing Pattern: Instruction and Control Parameter

    ERIC Educational Resources Information Center

    Southard, Dan

    2006-01-01

    The purpose of this study was to determine the effects of instruction and scaling up a control parameter (velocity of throw) on changes in throwing pattern. Sixty adult female throwers (ages 20-26 years) were randomly placed into one of four practice conditions: (a) scale up on velocity with no instruction, (b) maintain constant velocity with no…

  10. Effects of different dosages of oxycodone and fentanyl on the hemodynamic changes during intubation.

    PubMed

    Park, Ki-Bum; Ann, Junggun; Lee, Haemi

    2016-08-01

    To investigate the effectiveness of oxycodone compared with fentanyl for attenuating the hemodynamic response during endotracheal intubation. This study was conducted from June 2014 to February 2015 on healthy adults undergoing general anesthesia at the Yeungnam University Hospital, Daegu, Republic of Korea. Ninety-five patients were randomly assigned to one of 3 groups to receive the following drugs; Group F: fentanyl 2 μg/kg; Group O/70: oxycodone 140 μg/kg; Group O/100: oxycodone 200 μg/kg. Five minutes after injection of the study drug, general anesthesia was induced with propofol 1.5 mg/kg and rocuronium 0.8 mg/kg. The mean blood pressure (MBP), heart rate (HR), peripheral oxygen saturation (SpO2), and bispectral index (BIS) were compared before administration of the study drug (T1), just before endotracheal intubation (T2), one minute after endotracheal intubation (T3), and 7.5 minutes after endotracheal intubation (T4). Complications were assessed. The 2 oxycodone groups showed no significant differences in MBP, HR, SpO2, and BIS compared to Group F at the time points assessed. The incidence of complications was comparable among the groups.  Oxycodone could successfully be used to attenuate the sympathetic response during anesthetic induction. The hemodynamic profiles and incidence of complications were clinically similar among the groups, but Group O/70 tended to show a lower rate of complications of apnea.

  11. Intubating condition, hemodynamic parameters and upper airway morbidity: A comparison of intubating laryngeal mask airway with standard direct laryngoscopy

    PubMed Central

    Kavitha, J.; Tripathy, Debendra Kumar; Mishra, Sandeep Kumar; Mishra, Gayatri; Chandrasekhar, L. J.; Ezhilarasu, P.

    2011-01-01

    Background: Intubating Laryngeal Mask Airway (ILMA) is a relatively new device designed to have better intubating characteristics than the standard Laryngeal Mask Airway. This study was designed to compare Intubating Laryngeal Mask with standard Direct Laryngoscopy (DLS), taking into account ease of intubation, time taken for intubation, success rate of intubation, hemodynamic responses and upper airway morbidity. Materials and Methods: Sixty patients, ASA I or II, of age between 20 and 60 years, were enrolled in this prospective and randomized study. They were randomly allocated to one of the two groups: group ILMA, Intubating Laryngeal Mask Airway; group DLS, Direct Laryngoscopy. The patients were intubated orally using either equipment after induction of general anesthesia. Results and Conclusions: DLS is comparatively a faster method to secure tracheal intubation than Intubating Laryngeal Mask. ILMA offers no advantage in attenuating the hemodynamic responses compared to direct laryngoscope. The success rate of intubation through Intubating Laryngeal Mask is comparable with that of DLS. The upper airway morbidity and mean oxygen saturation are comparable in both the groups. PMID:25885300

  12. Functional hemodynamic monitoring

    PubMed Central

    Pinsky, Michael R; Payen, Didier

    2005-01-01

    Hemodynamic monitoring is a central component of intensive care. Patterns of hemodynamic variables often suggest cardiogenic, hypovolemic, obstructive, or distributive (septic) etiologies to cardiovascular insufficiency, thus defining the specific treatments required. Monitoring increases in invasiveness, as required, as the risk for cardiovascular instability-induced morbidity increases because of the need to define more accurately the diagnosis and monitor the response to therapy. Monitoring is also context specific: requirements during cardiac surgery will be different from those in the intensive care unit or emergency department. Solitary hemodynamic values are useful as threshold monitors (e.g. hypotension is always pathological, central venous pressure is only elevated in disease). Some hemodynamic values can only be interpreted relative to metabolic demand, whereas others have multiple meanings. Functional hemodynamic monitoring implies a therapeutic application, independent of diagnosis such as a therapeutic trial of fluid challenge to assess preload responsiveness. Newer methods for assessing preload responsiveness include monitoring changes in central venous pressure during spontaneous inspiration, and variations in arterial pulse pressure, systolic pressure, and aortic flow variation in response to vena caval collapse during positive pressure ventilation or passive leg raising. Defining preload responsiveness using these functional measures, coupled to treatment protocols, can improve outcome from critical illness. Potentially, as these and newer, less invasive hemodynamic measures are validated, they could be incorporated into such protocolized care in a cost-effective manner. PMID:16356240

  13. Effects of incomplete stent apposition on the changes in hemodynamics inside a curved and calcified coronary artery

    NASA Astrophysics Data System (ADS)

    Poon, Eric; Ooi, Andrew; Barlis, Peter; Hayat, Umair; Moore, Stephen

    2014-11-01

    Percutaneous coronary intervention (PCI) is the modern gold standard for treatment of coronary artery disease. Stenting (a common PCI procedure) of simple lesion inside a relatively straight segment of coronary artery has proven to be highly successful. However, incomplete stent apposition (ISA) where there is a lack of contact between the stent struts and lumen wall is not uncommon in curved and calcified coronary arteries. Computational fluid dynamics simulations are carried out to study the changes in hemodynamics as a result of ISA inside a curved and calcified coronary artery. For a 3 mm coronary artery, we simulate a resting condition at 80 mL/min and a range of hyperemic conditions with coronary flow reserve in between 1 and 2. The heartbeat is fixed at 75 BPM. Five different curvatures of the coronary artery are considered. Negative effects on hemodynamic variables, such as low wall shear stress (<0.5 Pa); high wall shear stress gradient (>5,000 Pa/m) and oscillation shear index (0 <= OSI <= 0.5), are employed to identify locations with high possibilities of adverse clinical events. This study will lead to better understandings of ISA in curved and calcified coronary arteries and help improve future coronary stent deployment. Supported by the Australian Research Council (LP120100233) and Victorian Life Sciences Computation Initiative (VR0210).

  14. C5a-induced hemodynamic and hematologic changes in the rabbit. Role of cyclooxygenase products and polymorphonuclear leukocytes.

    PubMed Central

    Lundberg, C.; Marceau, F.; Hugli, T. E.

    1987-01-01

    Hemodynamic and hematologic changes occurring after intravascular complement activation have implicated the anaphylatoxins in this response. In this study, the hemodynamic and hematologic effects of purified C5a were investigated in rabbits; and involvement of prostanoids, histamine, and polymorphonuclear leukocytes (PMNs) were examined. The anaphylatoxin C5a induces a reversible systemic arterial hypotension which coincides with an increase in central venous pressure (CVP), decreased cardiac output (CO), increased plasma prostanoid levels, as well as neutropenia. Total peripheral resistance (TPR) remained unchanged. The cyclooxygenase inhibitor indomethacin abolished the C5a-induced hypotension and normalized plasma prostanoid levels without altering the C5a-induced neutropenia. The thromboxane (Tx) A2 synthetase inhibitor dazoxiben reduced TxB2 plasma levels and increased 6-keto-prostaglandin PGF1 alpha and PGE2 levels without altering the hypotensive response. However, with dazoxiben treatment both TPR and CVP decreased. The H2-receptor antagonist cimetidine reduced C5a-induced hypotension and diminished prostanoid release. Both the hypotensive response and elevated prostanoid release were observed after C5a challenge in animals rendered neutropenic prior to challenge. It is concluded that C5a-induced arterial hypotension in the rabbit is a PMN-independent reaction, mediated through cyclooxygenase products and, to some degree, by histamine. The mechanism producing systemic arterial hypotension does not seem to involve peripheral vasodilation but appears to be a secondary effect of pulmonary vasoconstriction, possibly mediated by TxA2. PMID:3115110

  15. American College of Critical Care Medicine Clinical Practice Parameters for Hemodynamic Support of Pediatric and Neonatal Septic Shock.

    PubMed

    Davis, Alan L; Carcillo, Joseph A; Aneja, Rajesh K; Deymann, Andreas J; Lin, John C; Nguyen, Trung C; Okhuysen-Cawley, Regina S; Relvas, Monica S; Rozenfeld, Ranna A; Skippen, Peter W; Stojadinovic, Bonnie J; Williams, Eric A; Yeh, Tim S; Balamuth, Fran; Brierley, Joe; de Caen, Allan R; Cheifetz, Ira M; Choong, Karen; Conway, Edward; Cornell, Timothy; Doctor, Allan; Dugas, Marc-Andre; Feldman, Jonathan D; Fitzgerald, Julie C; Flori, Heidi R; Fortenberry, James D; Graciano, Ana Lia; Greenwald, Bruce M; Hall, Mark W; Han, Yong Yun; Hernan, Lynn J; Irazuzta, Jose E; Iselin, Elizabeth; van der Jagt, Elise W; Jeffries, Howard E; Kache, Saraswati; Katyal, Chhavi; Kissoon, Niranjan Tex; Kon, Alexander A; Kutko, Martha C; MacLaren, Graeme; Maul, Timothy; Mehta, Renuka; Odetola, Fola; Parbuoni, Kristine; Paul, Raina; Peters, Mark J; Ranjit, Suchitra; Reuter-Rice, Karin E; Schnitzler, Eduardo J; Scott, Halden F; Torres, Adalberto; Weingarten-Abrams, Jacki; Weiss, Scott L; Zimmerman, Jerry J; Zuckerberg, Aaron L

    2017-06-01

    The American College of Critical Care Medicine provided 2002 and 2007 guidelines for hemodynamic support of newborn and pediatric septic shock. Provide the 2014 update of the 2007 American College of Critical Care Medicine "Clinical Guidelines for Hemodynamic Support of Neonates and Children with Septic Shock." Society of Critical Care Medicine members were identified from general solicitation at Society of Critical Care Medicine Educational and Scientific Symposia (2006-2014). The PubMed/Medline/Embase literature (2006-14) was searched by the Society of Critical Care Medicine librarian using the keywords: sepsis, septicemia, septic shock, endotoxemia, persistent pulmonary hypertension, nitric oxide, extracorporeal membrane oxygenation, and American College of Critical Care Medicine guidelines in the newborn and pediatric age groups. The 2002 and 2007 guidelines were widely disseminated, translated into Spanish and Portuguese, and incorporated into Society of Critical Care Medicine and American Heart Association/Pediatric Advanced Life Support sanctioned recommendations. The review of new literature highlights two tertiary pediatric centers that implemented quality improvement initiatives to improve early septic shock recognition and first-hour compliance to these guidelines. Improved compliance reduced hospital mortality from 4% to 2%. Analysis of Global Sepsis Initiative data in resource rich developed and developing nations further showed improved hospital mortality with compliance to first-hour and stabilization guideline recommendations. The major new recommendation in the 2014 update is consideration of institution-specific use of 1) a "recognition bundle" containing a trigger tool for rapid identification of patients with septic shock, 2) a "resuscitation and stabilization bundle" to help adherence to best practice principles, and 3) a "performance bundle" to identify and overcome perceived barriers to the pursuit of best practice principles.

  16. Goal directed hemodynamic therapy based in esophageal Doppler flow parameters: A systematic review, meta-analysis and trial sequential analysis.

    PubMed

    Ripollés-Melchor, J; Casans-Francés, R; Espinosa, A; Abad-Gurumeta, A; Feldheiser, A; López-Timoneda, F; Calvo-Vecino, J M

    2016-01-01

    Numerous studies have compared perioperative esophageal doppler monitoring (EDM) guided intravascular volume replacement strategies with conventional clinical volume replacement in surgical patients. The use of the EDM within hemodynamic algorithms is called 'goal directed hemodynamic therapy' (GDHT). Meta-analysis of the effects of EDM guided GDHT in adult non-cardiac surgery on postoperative complications and mortality using PRISMA methodology. A systematic search was performed in Medline, PubMed, EMBASE, and the Cochrane Library (last update, March 2015). Randomized clinical trials (RCTs) in which perioperative GDHT was compared to other fluid management. Overall complications. Mortality; number of patients with complications; cardiac, renal and infectious complications; incidence of ileus. Studies were subjected to quantifiable analysis, pre-defined subgroup analysis (stratified by surgery, type of comparator and risk); pre-defined sensitivity analysis and trial sequential analysis (TSA). Fifty six RCTs were initially identified, 15 fulfilling the inclusion criteria, including 1,368 patients. A significant reduction was observed in overall complications associated with GDHT compared to other fluid therapy (RR=0.75; 95%CI: 0.63-0.89; P=0.0009) in colorectal, urological and high-risk surgery compared to conventional fluid therapy. No differences were found in secondary outcomes, neither in other subgroups. The impact on preventing the development of complications in patients using EDM is high, causing a relative risk reduction (RRR) of 50% for a number needed to treat (NNT)=6. GDHT guided by EDM decreases postoperative complications, especially in patients undergoing colorectal surgery and high-risk surgery. However, no differences versus restrictive fluid therapy and in intermediate-risk patients were found. Copyright © 2015 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Publicado por Elsevier España, S.L.U. All rights reserved.

  17. Earliest Bedside Assessment of Hemodynamic Parameters and Cardiac Biomarkers: Their Role as Predictors of Adverse Outcome in Patients with Septic Shock

    PubMed Central

    Sasko, Benjamin; Butz, Thomas; Prull, Magnus Wilhelm; Liebeton, Jeanette; Christ, Martin; Trappe, Hans-Joachim

    2015-01-01

    Background: Early assessment and aggressive hemodynamic treatment have been shown to increase the survival of patients in septic shock. Current and past sepsis guidelines recommend a resuscitation protocol including central venous pressure (CVP), mean arterial blood pressure (MAP), urine output and central venous oxygen saturation (ScvO2) for resuscitation within the first six hours. Currently, the established severity score systems like APACHE II score, SOFA score or SAPS II score predict the outcome of critically ill patients on the bases of variables obtained only after the first 24 hours. The present study aims to evaluate the risk of short-term mortality for patients with septic shock by the earliest possible assessment of hemodynamic parameters and cardiac biomarkers as well as their role for the prediction of the adverse outcome. Methods: 52 consecutive patients treated for septic shock in the intensive care unit of one centre (Marien Hospital Herne, Ruhr University Bochum, Germany) were prospectively enrolled in this study. Hemodynamic parameters (MAP, CVP, ScvO2, left ventricular ejection fraction, Hematocrit) and cardiac biomarkers (Troponin I) at the ICU admission were evaluated in regard to their influence on mortality. The primary endpoint was all-cause mortality within 28 days after the admission. Results: A total of 52 patients (31 male, 21 female) with a mean age of 71.4±8.5 years and a mean APACHE II score of 37.0±7.6 were enrolled in the study. 28 patients reached the primary endpoint (mortality 54%). Patients presenting with hypotension (MAP <65 mmHg) at ICU admission had significantly higher rates of 28-day mortality as compared with the group of patients without hypotension (28-day mortality rate 74 % vs. 32 %, p<0.01). Furthermore, the patients in the hypotension present group had significantly higher lactate concentration (p=0.002), higher serum creatinin (p=0.04), higher NTproBNP (p=0.03) and after the first 24 hours higher APACHE II

  18. Hemodynamic changes in patients with extracorporeal membrane oxygenation (ECMO) demonstrated by contrast-enhanced CT examinations - implications for image acquisition technique.

    PubMed

    Lambert, Lukas; Grus, Tomas; Balik, Martin; Fichtl, Jaromir; Kavan, Jan; Belohlavek, Jan

    2017-04-01

    Extracorporeal membrane oxygenation (ECMO) is an established tool for respiratory and circulatory support. In computed tomography, altered hemodynamics in ECMO patients requires special considerations and handling in contrast injection and its timing. In this article, we demonstrate changes in hemodynamics in ECMO patients captured on contrast-enhanced CT examinations and pitfalls in strategies for contrast injection in relation to the ECMO flow, cardiac function and the placement of ECMO cannulas. Contrast-enhanced CT of patients with ECMO requires prior knowledge of the ECMO cannulas, central venous lines, changes of hemodynamics induced by low cardiac output and the influence of adjustment of ECMO on blood flow in order to optimize injection of the contrast material and timing of the scan. Special considerations include temporary reduction of the ECMO flow, selection of the injection site and increasing volume or flow rate of the contrast material.

  19. The quantification of hemodynamic parameters downstream of a Gianturco Zenith stent wire using newtonian and non-newtonian analog fluids in a pulsatile flow environment.

    PubMed

    Walker, Andrew M; Johnston, Clifton R; Rival, David E

    2012-11-01

    Although deployed in the vasculature to expand vessel diameter and improve blood flow, protruding stent struts can create complex flow environments associated with flow separation and oscillating shear gradients. Given the association between magnitude and direction of wall shear stress (WSS) and endothelial phenotype expression, accurate representation of stent-induced flow patterns is critical if we are to predict sites susceptible to intimal hyperplasia. Despite the number of stents approved for clinical use, quantification on the alteration of hemodynamic flow parameters associated with the Gianturco Z-stent is limited in the literature. In using experimental and computational models to quantify strut-induced flow, the majority of past work has assumed blood or representative analogs to behave as Newtonian fluids. However, recent studies have challenged the validity of this assumption. We present here the experimental quantification of flow through a Gianturco Z-stent wire in representative Newtonian and non-Newtonian blood analog environments using particle image velocimetry (PIV). Fluid analogs were circulated through a closed flow loop at physiologically appropriate flow rates whereupon PIV snapshots were acquired downstream of the wire housed in an acrylic tube with a diameter characteristic of the carotid artery. Hemodynamic parameters including WSS, oscillatory shear index (OSI), and Reynolds shear stresses (RSS) were measured. Our findings show that the introduction of the stent wire altered downstream hemodynamic parameters through a reduction in WSS and increases in OSI and RSS from nonstented flow. The Newtonian analog solution of glycerol and water underestimated WSS while increasing the spatial coverage of flow reversal and oscillatory shear compared to a non-Newtonian fluid of glycerol, water, and xanthan gum. Peak RSS were increased with the Newtonian fluid, although peak values were similar upon a doubling of flow rate. The introduction of the

  20. Carotid artery hemodynamics: observing patient-specific changes with amlodipine and lisinopril by using MR imaging computation fluid dynamics.

    PubMed

    Ariff, Ben B; Glor, Fadi P; Crowe, Lindsey; Xu, Xiao Y; Vennart, William; Firmin, David N; Thom, Simon M; Hughes, Alun D

    2010-12-01

    To assess whether using magnetic resonance (MR) imaging combined with computational fluid dynamics (CFD) could reveal changes in common carotid artery (CCA) flow and wall shear stress (WSS) that might contribute to differences in CCA remodeling between amlodipine, a calcium channel blocker, and lisinopril, an angiotensin-converting enzyme inhibitor, despite similar reductions in blood pressure (BP). Institutional review board approval was obtained, and participants gave informed consent. Nine subjects with hypertension were recruited into a double-blind placebo-controlled randomized three-way crossover study to compare the hemodynamic effects of 7 days of treatment with placebo, amlodipine, or lisinopril. After each treatment period, patients underwent CCA ultrasonography, BP measurement, and MR imaging with CFD. Analyses were performed by using repeated-measures analysis of variance, followed by the Tukey test or the Wilcoxon matched-pairs test. Amlodipine and lisinopril lowered BP similarly, but CCA flow rate was significantly higher (P < .01) and distal vascular resistance was lower (P = .016) after amlodipine treatment than after lisinopril treatment. WSS on the inner wall of the CCA was significantly lower after lisinopril treatment than after amlodipine treatment (P = .03). The change in WSS in the CCA correlated with the change in vascular resistance (r = -0.85, P < .001). Amlodipine causes increased blood flow and increased time-averaged WSS in the CCA compared with lisinopril, despite similar reductions in BP. Differences in the subacute hemodynamic effects of amlodipine and lisinopril could contribute to the differences in CCA remodeling seen in long-term studies. http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.10100788/-/DC1. © RSNA, 2010

  1. Hemodynamic Changes in Left Anterior Descending Coronary Artery and Anterior Interventricular Vein during Right Ventricular Apical Pacing: A Doppler Ultrasound Study in Open Chest Beagles

    PubMed Central

    Fu, Ying; Long, Bin; Shen, Jie; Su, Li; Yin, Lixue

    2013-01-01

    Objective The aim of this study was to quantify the effects of right ventricular apical pacing (RVAP) on hemodynamics in left anterior descending coronary artery (LAD) and anterior interventricular vein (AIV) contrast to baseline condition in open chest beagles using Doppler ultrasound imaging. Methods In 6 anesthetized open chest beagles, the spectral Doppler waveforms of the middle segmental LAD and the AIV were acquired with a 5 MHz linear array transducer at baseline condition and during RVAP. The aortic pressure-time curves were recorded synchronously. The Doppler hemodynamic parameters of the LAD and AIV at both states were derived and compared. Results The spectral Doppler waveforms of the LAD had a principal diastolic positive wave (Dp), which heelled by a momentary negative wave and a positive wave during early systole at baseline condition. During RVAP, an additional negative wave appeared in the LAD at late systole. The duration of the Dp shortened (227.83±12.16 ms vs 188.50±8.97 ms, P<0.001), and the acceleration of the Dp decreased (11.85±2.22 m/s2 vs 3.54±0.42 m/s2, P<0.001). The spectral Doppler waveforms of the AIV only had a principal positive wave (Sp) at baseline condition, but an additional diastolic negative wave appeared during RVAP. The duration of the Sp shortened (242.99±7.98 ms vs 215.38±15.44 ms, P<0.001), and the acceleration of the Sp decreased (9.61±1.93 m/s2 vs 1.01±0.11 m/s2, P<0.001). Conclusions Obvious hemodynamic changes in the LAD and AIV during RVAP were observed, and these abnormal flow patterns in epicardial coronary arteries and vena coronaria may be sensitive and important hints of the disturbed cardiac electrical and mechanical activity sequences. PMID:23825640

  2. Pulse Waveform Changes in Macular Choroidal Hemodynamics With Regression of Acute Central Serous Chorioretinopathy.

    PubMed

    Saito, Michiyuki; Saito, Wataru; Hirooka, Kiriko; Hashimoto, Yuki; Mori, Shohei; Noda, Kousuke; Ishida, Susumu

    2015-10-01

    To quantitatively evaluate the pulse waveform changes in macular choroidal blood flow by using laser speckle flowgraphy (LSFG) with regression of acute central serous chorioretinopathy (CSC). This retrospective observational case series included 20 eyes of 20 patients with acute CSC. Laser speckle flowgraphy was performed at baseline and after 6 months. On the LSFG monochrome map, automatically divided 5 × 5 grid segments within the macula were classified into predominantly delayed filling (PDF) or minimally or no delayed filling (MDF) areas according to the degree of choroidal filling delay on early-phase indocyanine green angiography. The average mean blur rate (MBR) and the pulse waveform parameters, including the skew and blowout time (BOT), were compared between the total PDF and MDF areas during follow-up. The average MBR significantly decreased in both PDF (P = 0.005) and MDF (P < 0.001) areas during follow-up; in both areas, the skew decreased (P < 0.001 and P = 0.006, respectively) and BOT increased (P < 0.001 for each), showing significant reduction in vascular resistance at 6 months. The degree of the changes in the skew and BOT was significantly larger (P = 0.02 and P < 0.001, respectively) in the PDF area than in the MDF area. Changes in the skew and BOT, indices for vascular resistance, confirmed the involvement of circulatory disturbance at the acute stage of CSC. The present findings suggested that the pathogenesis of CSC stems from imbalanced distribution of choroidal blood flow due to augmented vascular resistance.

  3. Optimal dose of intravenous oxycodone for attenuating hemodynamic changes after endotracheal intubation in healthy patients

    PubMed Central

    Park, Yong-Hee; Lee, Seung-Hyuk; Lee, Oh Haeng; Kang, Hyun; Shin, Hwa-Yong; Baek, Chong-Wha; Jung, Yong Hun; Woo, Young Cheol

    2017-01-01

    Abstract Background: Intravenous oxycodone has been used as an adjunct to anesthetic agents. This study aimed to assess the optimal dose of intravenous oxycodone for the attenuation of the hemodynamic responses to laryngoscopy and endotracheal intubation. Methods: A prospective, randomized, double-blind study was conducted. Ninety-five patients were randomly divided into 5 groups based on the oxycodone dose: 0, 0.05, 0.1, 0.15, 0.2 mg/kg. After administering the assigned dose of intravenous oxycodone, anesthesia was induced with thiopental. Heart rate (HR) and blood pressure (BP) were measured at baseline, before intubation, and 1, 2, and 3 minutes after intubation. The percentage increase of BP was calculated as (highest BP after intubation − baseline BP)/baseline BP × 100 (%). The percentage increase of HR was calculated in same formula as above. Hypertension was defined as a 15% increase of systolic BP from baseline, and probit analysis was conducted. Results: Hemodynamic data from 86 patients were analyzed. The percentage increase of mean arterial pressure after intubation in groups 0.05, 0.1, 0.15, and 0.2 was significantly different from that in the control (P < 0.001). For HR, the percentage increase was lower than control group when oxycodone was same or more than 0.1 mg/kg (P < 0.05). Using probit analysis, the 95% effective dose (ED95) for preventing hypertension was 0.159 mg/kg (95% confidence interval [CI], 0.122–0.243). In addition, ED50 was 0.020 mg/kg (95% CI, −0.037 to 0.049). However, oxycodone was not effective for maintaining the HR in our study dosage. There were no significant differences in the incidence of hypotension during induction between groups. Conclusions: Using 0.1 mg/kg of intravenous oxycodone is sufficient to attenuate the increase of BP and HR during induction period in healthy patients. The ED95, which was 0.159 mg/kg, can be useful to adjust the dosage of IV oxycodone for maintain stable BP

  4. A rapid method to non-invasively estimate training-induced hemodynamic changes in top-level athletes.

    PubMed

    D'Ascenzi, Flavio; Solari, Marco; Focardi, Marta; Cameli, Matteo; Bonifazi, Marco; Mondillo, Sergio

    2016-10-01

    The estimation of cardiovascular adaptation to exercise provides valuable information on training status. However, albeit of interest, it has been rarely used in athletes, being the current non-invasive techniques expensive and requiring specialist expertise. Recently, a new bioreactance-based method is available; however, no data have been collected in trained athletes. The aim of this prospective, longitudinal study was to evaluate by bioreactance the training-induced hemodynamic changes. Ten top-level basketball players were enrolled. Bioreactance analysis was performed at the beginning and after 5 months of training and an echocardiographic examination was simultaneously performed. After training, no significant differences were found in cardiac output (P=0.68) and in cardiac index (P=0.78). Diastolic blood pressure significantly decreased (P<0.05) and a non-significant decrease in peripheral resistance was observed (P=0.57). A significant increase in thoracic fluid content was observed after training (P<0.05). While absolute values were different between bioreactance and echocardiography, a similar trend of exercise-induced hemodynamic changes was found. Both before and after training, an inverse relationship between TPR and CO (r=-0.818, P<0.005; r=-0.891, P=0.001, respectively) and between TPR and SV was found (r=-0.794, P=0.006; r=-0.745, P<0.05, respectively). Bioreactance-derived method represents a novel non-invasive technique able to provide a rapid and comprehensive evaluation of cardiovascular response to training. Using trends rather than single, isolated measurements, this method could provide useful data on the cardiovascular response to training in competitive athletes.

  5. Effects of lidocaine and esmolol infusions on hemodynamic changes, analgesic requirement, and recovery in laparoscopic cholecystectomy operations.

    PubMed

    Dogan, Serpil Dagdelen; Ustun, Faik Emre; Sener, Elif Bengi; Koksal, Ersin; Ustun, Yasemin Burcu; Kaya, Cengiz; Ozkan, Fatih

    2016-01-01

    We compared the effects of lidocaine and esmolol infusions on intraoperative hemodynamic changes, intraoperative and postoperative analgesic requirements, and recovery in laparoscopic cholecystectomy surgery. The first group (n=30) received IV lidocaine infusions at a rate of 1.5mg/kg/min and the second group (n=30) received IV esmolol infusions at a rate of 1mg/kg/min. Hemodynamic changes, intraoperative and postoperative analgesic requirements, and recovery characteristics were evaluated. In the lidocaine group, systolic arterial blood pressures values were lower after the induction of anesthesia and at 20min following surgical incision (p<0.05). Awakening time was shorter in the esmolol group (p<0.001); Ramsay Sedation Scale scores at 10min after extubation were lower in the esmolol group (p<0.05). The modified Aldrete scores at all measurement time points during the recovery period were relatively lower in the lidocaine group (p<0.05). The time to attain a modified Aldrete score of ≥9 points was prolonged in the lidocaine group (p<0.01). Postoperative resting and dynamic VAS scores were higher in the lidocaine group at 10 and 20min after extubation (p<0.05, p<0.01, respectively). Analgesic supplements were less frequently required in the lidocaine group (p<0.01). In laparoscopic cholecystectomies, lidocaine infusion had superiorities over esmolol infusions regarding the suppression of responses to tracheal extubation and postoperative need for additional analgesic agents in the long run, while esmolol was more advantageous with respect to rapid recovery from anesthesia, attenuation of early postoperative pain, and modified Aldrete recovery (MAR) scores and time to reach MAR score of 9 points. Copyright © 2014 Sociedade Brasileira de Anestesiologia. Published by Elsevier Editora Ltda. All rights reserved.

  6. [Effects of lidocaine and esmolol infusions on hemodynamic changes, analgesic requirement, and recovery in laparoscopic cholecystectomy operations].

    PubMed

    Dogan, Serpil Dagdelen; Ustun, Faik Emre; Sener, Elif Bengi; Koksal, Ersin; Ustun, Yasemin Burcu; Kaya, Cengiz; Ozkan, Fatih

    2016-01-01

    We compared the effects of lidocaine and esmolol infusions on intraoperative hemodynamic changes, intraoperative and postoperative analgesic requirements, and recovery in laparoscopic cholecystectomy surgery. The first group (n=30) received IV lidocaine infusions at a rate of 1.5mg/kg/min and the second group (n=30) received IV esmolol infusions at a rate of 1mg/kg/min. Hemodynamic changes, intraoperative and postoperative analgesic requirements, and recovery characteristics were evaluated. In the lidocaine group, systolic arterial blood pressures values were lower after the induction of anesthesia and at 20min following surgical incision (p<0.05). Awakening time was shorter in the esmolol group (p<0.001); Ramsay Sedation Scale scores at 10min after extubation were lower in the esmolol group (p<0.05). The modified Aldrete scores at all measurement time points during the recovery period were relatively lower in the lidocaine group (p<0.05). The time to attain a modified Aldrete score of ≥9 points was prolonged in the lidocaine group (p<0.01). Postoperative resting and dynamic VAS scores were higher in the lidocaine group at 10 and 20min after extubation (p<0.05, p<0.01, respectively). Analgesic supplements were less frequently required in the lidocaine group (p<0.01). In laparoscopic cholecystectomies, lidocaine infusion had superiorities over esmolol infusions regarding the suppression of responses to tracheal extubation and postoperative need for additional analgesic agents in the long run, while esmolol was more advantageous with respect to rapid recovery from anesthesia, attenuation of early postoperative pain, and modified Aldrete recovery (MAR) scores and time to reach MAR score of 9 points. Copyright © 2014. Publicado por Elsevier Editora Ltda.

  7. Hemodynamic changes during whole body surface cooling and lower body negative pressure

    NASA Technical Reports Server (NTRS)

    Raven, P. B.; Pape, G.; Taylor, W. F.; Gaffney, F. A.; Blomqvist, C. G.

    1981-01-01

    Six young healthy male subjects were studied to evaluate the use of whole body surface cooling (WBSC) as an antiorthostatic intervention. Previous studies have demonstrated that perfusion of an Apollo cooling garment with 16 C water produced a significant increase in stroke volume and decrease in heart rate at rest and during lower body negative pressure (LBNP). However, optimal perfusion temperatures have not been determined. The present study examined the effects of WBSC using perfusion of water at a temperature of 10 C. This perfusion temperature produced a greater decrease in mean skin temperature than water at 16 C (4 C drop compared to 2 C). The hemodynamic effects were also more prominent with 10 C water as shown by the increase in stroke volume of 11% at rest and of 35% during LBNP at -50 torr compared to control measurements at ambient temperature. Heart rates were lowered significantly (8 beats/min) and systolic arterial blood pressure was higher (8 torr). Cooling with 10 C water produced a slight increase in muscle tone, reflected by a small but significant increase (+84 ml/min) in oxygen uptake. These data suggest that WBSC is an effective nonpharmacologic means of controlling preload and deserves further investigation as an antiorthostatic intervention.

  8. Hemodynamic changes during whole body surface cooling and lower body negative pressure

    NASA Technical Reports Server (NTRS)

    Raven, P. B.; Pape, G.; Taylor, W. F.; Gaffney, F. A.; Blomqvist, C. G.

    1981-01-01

    Six young healthy male subjects were studied to evaluate the use of whole body surface cooling (WBSC) as an antiorthostatic intervention. Previous studies have demonstrated that perfusion of an Apollo cooling garment with 16 C water produced a significant increase in stroke volume and decrease in heart rate at rest and during lower body negative pressure (LBNP). However, optimal perfusion temperatures have not been determined. The present study examined the effects of WBSC using perfusion of water at a temperature of 10 C. This perfusion temperature produced a greater decrease in mean skin temperature than water at 16 C (4 C drop compared to 2 C). The hemodynamic effects were also more prominent with 10 C water as shown by the increase in stroke volume of 11% at rest and of 35% during LBNP at -50 torr compared to control measurements at ambient temperature. Heart rates were lowered significantly (8 beats/min) and systolic arterial blood pressure was higher (8 torr). Cooling with 10 C water produced a slight increase in muscle tone, reflected by a small but significant increase (+84 ml/min) in oxygen uptake. These data suggest that WBSC is an effective nonpharmacologic means of controlling preload and deserves further investigation as an antiorthostatic intervention.

  9. Hemodynamic effects of long-term morphological changes in the human carotid sinus.

    PubMed

    Seong, Jaehoon; Jeong, Woowon; Smith, Nataliya; Towner, Rheal A

    2015-04-13

    Previous investigations of morphology for human carotid artery bifurcation from infancy to young adulthood found substantial growth of the internal carotid artery with advancing age, and the development of the carotid sinus at the root of the internal carotid artery during teenage years. Although the reasons for the appearance of the carotid sinus are not clearly understood yet, it has been hypothesized that the dilation of the carotid sinus serves to support pressure sensing, and slows the blood flow to reduce pulsatility to protect the brain. In order to understand this interesting evolvement at the carotid bifurcation in the aspects of fluid mechanics, we performed in vitro phase-contrast MR flow experiments using compliant silicone replicas of age-dependent carotid artery bifurcations. The silicone models in childhood, adolescence, and adulthood were fabricated using a rapid prototyping technique, and incorporated with a bench-top flow mock circulation loop using a computer-controlled piston pump. The results of the in vitro flow study showed highly complex flow characteristics at the bifurcation in all age-dependent models. However, the highest magnitude of kinetic energy was found at the internal carotid artery in the child model. The high kinetic energy in the internal carotid artery during childhood might be one of the local hemodynamic forces that initiate morphological long-term development of the carotid sinus in the human carotid bifurcation.

  10. Characterization of early changes in fetoplacental hemodynamics in a diet-induced rabbit model of IUGR.

    PubMed

    López-Tello, J; Barbero, A; González-Bulnes, A; Astiz, S; Rodríguez, M; Formoso-Rafferty, N; Arias-Álvarez, M; Rebollar, P G

    2015-10-01

    Intrauterine growth restriction (IUGR) is associated with adverse perinatal outcomes and late-onset diseases in offspring. Eating disorders, voluntary caloric restriction and maternal undernutrition can all induce IUGR but a relevant model is required to measure all its possible consequences. In this work, pregnant rabbits were used as an IUGR model. Control females (n=4) received ad libitum diet throughout pregnancy, whereas underfed females (n=5) were restricted to 50% of their daily requirements. Offspring size was measured by ultrasonography and in vivo at birth. Hemodynamic features of the umbilical cords and middle cerebral arteries (systolic peak velocity, end diastolic velocity, pulsatility index and resistance index) were characterized by Doppler ultrasonography. At day 21, maternal underfeeding resulted in a significant reduction of fetal size (occipito-nasal length). At birth, the size of kits from the underfed group was significantly lower (lower crown-rump length, biparietal and transversal thoracic diameters) and a reduced weight with respect to the control group. Feed restriction altered blood flow perfusion compared with does fed ad libitum (significant higher systolic peak, time-averaged mean velocities and lower end diastolic velocity). Fetuses affected by IUGR presented with compensative brain-sparing effects when compared with the control group. In conclusion, the present study supports using rabbits and the underfeeding approach as a valuable model for IUGR studies. These results may help to characterize IUGR alterations due to nutrient restriction of mothers in future research.

  11. A synopsis of 2007 ACCM clinical practice parameters for hemodynamic support of term newborn and infant septic shock.

    PubMed

    Carcillo, Joseph A

    2014-03-01

    This is a synopsis of the term newborn and infant portion of the 2007 document (Brierley et al., Crit Care Med 2009;37(2):666-88) which examined and graded new studies performed to test the utility and efficacy of the 2002 recommendations. This 2007 document examined and graded relevant new treatment and outcome studies to determine to what degree, if any, the 2002 guidelines should be modified. More than 30 clinical investigators and clinicians affiliated with the Society of Critical Care Medicine who had special interest in hemodynamic support of pediatric patients with sepsis volunteered to be members of the "update" task force. Subcommittees were formed to review and grade the literature using the evidence-based scoring system of the American College of Critical Care Medicine. The literature was accrued in part by searching PUBMED/MEDLINE using the following keywords: sepsis, septicemia, septic shock, endotoxemia, persistent pulmonary hypertension, nitric oxide, and ECMO. The search was narrowed to identify studies specifically relevant to term newborns, infants, and children. "Best Practice Outcomes" were identified and described clinical practice in these centers was used as a model. The new taskforce is presently working on updating new guidelines evaluating the literature of the past 6 years. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  12. Effects of diaphragmatic contraction on lower limb venous return and central hemodynamic parameters contrasting healthy subjects versus heart failure patients at rest and during exercise

    PubMed Central

    Balzan, Fernanda Machado; da Silva, Régis Chiarelli; da Silva, Danton Pereira; Sanches, Paulo Roberto Stefani; Tavares, Angela Maria Vicente; Ribeiro, Jorge Pinto; Berton, Danilo Cortozi; Clausell, Nadine Oliveira

    2014-01-01

    Abstract The main objective was to assess the effects of abdominal breathing (AB) versus subject's own breathing on femoral venous blood flow (Qfv) and their repercussions on central hemodynamics at rest and during exercise contrasting healthy subjects versus heart failure (HF) patients. We measured esophageal and gastric pressure (PGA), Qfv and parameters of central hemodynamics in eight healthy subjects and nine HF patients, under four conditions: subject's own breathing and AB (∆PGA ≥ 6 cmH2O) at rest and during knee extension exercises (15% of 1 repetition maximum) until exhaustion. Qfv and parameters of central hemodynamics [stroke volume (SV), cardiac output (CO)] were measured using Doppler ultrasound and impedance cardiography, respectively. At rest, healthy subjects Qfv, SV, and CO were higher during AB than subject's breathing (0.11 ± 0.02 vs. 0.06 ± 0.00 L·min−1, 58.7 ± 3.4 vs. 50.1 ± 4.1 mL and 4.4 ± 0.2 vs. 3.8 ± 0.1 L·min−1, respectively, P ≤ 0.05). ∆SV correlated with ∆PGA during AB (r = 0.89, P ≤ 0.05). This same pattern of findings induced by AB was observed during exercise (SV: 71.1 ± 4.1 vs. 65.5 ± 4.1 mL and CO: 6.3 ± 0.4 vs. 5.2 ± 0.4 L·min−1; P ≤ 0.05); however, Qfv did not reach statistical significance. The HF group tended to increase their Qfv during AB (0.09 ± 0.01 vs. 0.07 ± 0.03 L·min−1, P = 0.09). On the other hand, unlike the healthy subjects, AB did not improve SV or CO neither at rest nor during exercise (P > 0.05). In healthy subjects, abdominal pump modulated venous return improved SV and CO at rest and during exercise. In HF patients, with elevated right atrial and vena caval system pressures, these findings were not observed. PMID:25501441

  13. Effects of diaphragmatic contraction on lower limb venous return and central hemodynamic parameters contrasting healthy subjects versus heart failure patients at rest and during exercise.

    PubMed

    Balzan, Fernanda Machado; da Silva, Régis Chiarelli; da Silva, Danton Pereira; Sanches, Paulo Roberto Stefani; Tavares, Angela Maria Vicente; Ribeiro, Jorge Pinto; Berton, Danilo Cortozi; Clausell, Nadine Oliveira

    2014-12-01

    The main objective was to assess the effects of abdominal breathing (AB) versus subject's own breathing on femoral venous blood flow (Qfv) and their repercussions on central hemodynamics at rest and during exercise contrasting healthy subjects versus heart failure (HF) patients. We measured esophageal and gastric pressure (PGA), Qfv and parameters of central hemodynamics in eight healthy subjects and nine HF patients, under four conditions: subject's own breathing and AB ( ∆: PGA ≥ 6 cmH2O) at rest and during knee extension exercises (15% of 1 repetition maximum) until exhaustion. Qfv and parameters of central hemodynamics [stroke volume (SV), cardiac output (CO)] were measured using Doppler ultrasound and impedance cardiography, respectively. At rest, healthy subjects Qfv, SV, and CO were higher during AB than subject's breathing (0.11 ± 0.02 vs. 0.06 ± 0.00 L·min(-1), 58.7 ± 3.4 vs. 50.1 ± 4.1 mL and 4.4 ± 0.2 vs. 3.8 ± 0.1 L·min(-1), respectively, P ≤ 0.05). ∆SV correlated with ∆PGA during AB (r = 0.89, P ≤ 0.05). This same pattern of findings induced by AB was observed during exercise (SV: 71.1 ± 4.1 vs. 65.5 ± 4.1 mL and CO: 6.3 ± 0.4 vs. 5.2 ± 0.4 L·min(-1); P ≤ 0.05); however, Qfv did not reach statistical significance. The HF group tended to increase their Qfv during AB (0.09 ± 0.01 vs. 0.07 ± 0.03 L·min(-1), P = 0.09). On the other hand, unlike the healthy subjects, AB did not improve SV or CO neither at rest nor during exercise (P > 0.05). In healthy subjects, abdominal pump modulated venous return improved SV and CO at rest and during exercise. In HF patients, with elevated right atrial and vena caval system pressures, these findings were not observed.

  14. Cystic endometrial hyperplasia-pyometra syndrome in bitches: identification of hemodynamic, inflammatory, and cell proliferation changes.

    PubMed

    Veiga, Gisele Almeida Lima; Miziara, Ricardo Henrique; Angrimani, Daniel Souza Ramos; Papa, Paula Carvalho; Cogliati, Bruno; Vannucchi, Camila Infantosi

    2017-01-01

    Cystic endometrial hyperplasia (CEH)-pyometra syndrome is one of the most common diseases of noncastrated female dogs. However, determination of etiological mechanisms and differential diagnosis of CEH-pyometra syndrome are undefined. The aim of this study is to compare immunohistochemically the expression of cyclooxygenase-2 (COX-2) inflammatory mediator, Ki-67 antigen proliferation marker, vascular endothelial growth factor (VEGF-A) angiogenesis mediator and its FLT-1 and KDR receptors, and correlate with Doppler velocimetry of uterine artery and endometrial vascularization in bitches with CEH-pyometra syndrome. Bitches were allocated into CEH-mucometra Group (n = 13), Pyometra Group (n = 11), and Control Group (n = 8). Pyometra Group presented cytoplasmatic staining intensity for COX-2, VEGF-A, and FLT-1 and KDR receptors in luminal epithelium cells significantly higher compared to CEH-mucometra and Control groups. For the glandular epithelium, Pyometra Group had higher immunostaining score for VEGF-A and its receptors (FLT-1 and KDR). Hemodynamic indexes showed negative correlation with VEGF-A and its receptors as well as with COX-2. On the other hand, uterine vascularization score showed positive correlation in relation to immunostaining of COX-2, VEGF-A, and receptors in the endometrium luminal epithelium. In conclusion, uterus of bitches with CEH-pyometra syndrome show inflammatory process characterized by COX-2 expression, resulting in greater expression of proliferative Ki-67 marker as tissue response against the infectious agent. Furthermore, the increased VEGF-A expression and its receptors in CEH-pyometra reflect the increased blood flow and lower vascular resistance. Therefore, canine pyometra is characterized by an inflammatory, proliferative, and vascular disorder. © The Authors 2016. Published by Oxford University Press on behalf of Society for the Study of Reproduction. All rights reserved. For permissions, please journals.permissions@oup.com.

  15. Association among SNAP-25 Gene "Dd"eI and "Mnl"I Polymorphisms and Hemodynamic Changes during Methylphenidate Use: A Functional Near-Infrared Spectroscopy Study

    ERIC Educational Resources Information Center

    Oner, Ozgur; Akin, Ata; Herken, Hasan; Erdal, Mehmet Emin; Ciftci, Koray; Ay, Mustafa Ertan; Bicer, Duygu; Oncu, Bedriye; Bozkurt, Ozlem Hekim; Munir, Kerim; Yazgan, Yanki

    2011-01-01

    Objective: To investigate the interaction of treatment-related hemodynamic changes with genotype status for Synaptosomal associated protein 25 (SNAP-25) gene in participants with attention deficit hyperactivity disorder (ADHD) on and off single dose short-acting methylphenidate treatment with functional near-infrared spectroscopy (fNIRS). Method:…

  16. Association among SNAP-25 Gene "Dd"eI and "Mnl"I Polymorphisms and Hemodynamic Changes during Methylphenidate Use: A Functional Near-Infrared Spectroscopy Study

    ERIC Educational Resources Information Center

    Oner, Ozgur; Akin, Ata; Herken, Hasan; Erdal, Mehmet Emin; Ciftci, Koray; Ay, Mustafa Ertan; Bicer, Duygu; Oncu, Bedriye; Bozkurt, Ozlem Hekim; Munir, Kerim; Yazgan, Yanki

    2011-01-01

    Objective: To investigate the interaction of treatment-related hemodynamic changes with genotype status for Synaptosomal associated protein 25 (SNAP-25) gene in participants with attention deficit hyperactivity disorder (ADHD) on and off single dose short-acting methylphenidate treatment with functional near-infrared spectroscopy (fNIRS). Method:…

  17. Postoperative right ventricular failure after left ventricular assist device placement is predicted by preoperative echocardiographic structural, hemodynamic, and functional parameters.

    PubMed

    Raina, Amresh; Seetha Rammohan, Harish Raj; Gertz, Zachary M; Rame, J Eduardo; Woo, Y Joseph; Kirkpatrick, James N

    2013-01-01

    Right ventricular failure (RVF) after left ventricular assist device (LVAD) implantation results in significant morbidity and mortality. Preoperative parameters from transthoracic echocardiography (TTE) that predict RVF after LVAD implantation might identify patients in need of temporary or permanent right ventricular (RV) mechanical or inotropic support. Records of all patients who had preoperative TTE before implantation of a permanent LVAD at our institution from 2008 to 2011 were screened, and 55 patients (age 54 ± 16 years, 71% male) were included: 26 had LVAD implantation alone with no postoperative RVF, 16 had LVAD implantation alone but experienced postoperative RVF, and 13 had initial biventricular assist devices (BIVADs). The LVAD with RVF and BIVAD groups (RVF group) were pooled for comparison with the LVAD patients without RVF (No RVF group). RV fractional area change (RV FAC) was significantly lower in the RVF group versus the No RVF group (24% vs 30%; P = .04). Tricuspid annular plane systolic excursion was not different among the groups (1.6 cm vs 1.5 cm; P = .53). Estimated right atrial pressure (RAP) was significantly higher in the RVF group versus the No RVF group (11 mm Hg vs 8 mm Hg; P = .04). Left atrial volume (LAV) index was lower in patients with RVF versus No RVF (27 mL/m(2) vs 40 mL/m(2); P = .008). Combining RV FAC, estimated RAP, and LAV index into an echocardiographic scoring system revealed that the TTE score was highly predictive of RVF (5.0 vs 2.8; P = .0001). In multivariate models combining the TTE score with clinical variables, the score was the most predictive of RVF (odds ratio 1.66, 95% confidence interval 1.06-2.62). Preoperative RV FAC, estimated RAP, and LAV index predict postoperative RVF in patients undergoing LVAD implantation. These parameters may be combined into a simple echocardiographic scoring system to provide an additional tool to risk-stratify patients being evaluated for LVAD implantation. Copyright

  18. Exercise hemodynamics during extended continuous flow left ventricular assist device support: the response of systemic cardiovascular parameters and pump performance.

    PubMed

    Martina, Jerson; de Jonge, Nicolaas; Rutten, Marcel; Kirkels, J Hans; Klöpping, Corinne; Rodermans, Ben; Sukkel, Eveline; Hulstein, Nelienke; Mol, Bas; Lahpor, Jaap

    2013-09-01

    Patients on continuous flow left ventricular assist devices (cf-LVADs) are able to return to an active lifestyle and perform all sorts of physical activities. This study aims to evaluate exercise hemodynamics in patients with a HeartMate II cf-LVAD (HM II). Thirty (30) patients underwent a bicycle exercise test. Along with exercise capacity, systemic cardiovascular responses and pump performance were evaluated at 6 and 12 months after HM II implantation. From rest to maximum exercise, heart rate increased from 87 ± 14 to 140 ± 32 beats/minute (bpm) (P<0.01), while systolic arterial blood pressure increased from 93 ± 12 to 116 ± 21 mm Hg (P<0.01). Total cardiac output (TCO) increased from 4.1 ± 1.1 to 8.5 ± 2.8 L/min (P<0.01) while pump flow increased less, from 5.1 ± 0.7 to 6.4 ± 0.6 L/min (P<0.01). Systemic vascular resistance (SVR) decreased from 1776 ± 750 to 1013 ± 83 dynes.s/cm(5) (P<0.001) and showed the strongest correlation with TCO (r= -0.72; P<0.01). Exercise capacity was affected by older age, while blood pressure increased significantly in men compared with women. Exercise capacity remained consistent at 6 and 12 months after HM II implantation, 51% ± 13% and 52% ± 13% of predicted VO2 max for normal subjects corrected for age and gender. In conclusion, pump flow of the HM II may contribute partially to TCO during exercise, while SVR was the strongest determinant of TCO. © 2013 Wiley Periodicals, Inc. and International Center for Artificial Organs and Transplantation.

  19. The hemodynamic status of preascitic cirrhosis: an evaluation under steady-state conditions and after postural change.

    PubMed

    Bernardi, M; Di Marco, C; Trevisani, F; De Collibus, C; Fornalé, L; Baraldini, M; Andreone, P; Cursaro, C; Zacá, F; Ligabue, A

    1992-08-01

    To assess the hemodynamic status of patients with compensated cirrhosis, mean arterial pressure, cardiac index and peripheral vascular resistance and markers of central (plasma concentrations of atrial natriuretic factor) and arterial volemia (plasma norepinephrine concentration, plasma renin activity) were studied in 10 patients and 10 healthy control subjects under steady-state conditions (after 2 hr of standing) and after assumption of the supine position (30, 60, and 120 min). After standing, neither hemodynamics nor markers of effective volemia differed significantly between controls and patients. By evaluating the areas under the curve during the 2 hr of supine posture, the increase in cardiac output and plasma natriuretic factor and the decrease in peripheral vascular resistance were greater in patients (2.59 +/- 0.43 [S.E.M.] L/min/hr; 32.8 +/- 7.2 pg/ml/hr -1,103 +/- 248.4 dyn.sec/cm5/hr, respectively) than in controls (0.53 +/- 0.24 L/min/hr, p = 0.005; 17.4 +/- 4.7 pg/ml/hr, p = 0.005; -265.5 +/- 206.2 dyn.sec/cm5/hr, p = 0.02). The declines in heart rate, plasma norepinephrine concentration and plasma renin activity did not differ significantly. Mean arterial pressure did not significantly change. Our results suggest that during periods of upright posture, cirrhotic patients in the preascitic stage, who are known to have expanded blood volume, compensate for dilatation of the splanchnic vascular bed through total hypervolemia. The latter becomes excessive during recumbency, leading to supernormal increases in venous return, central volemia and cardiac index. The decline in peripheral vascular resistance appears to be a compensatory mechanism to maintain steady arterial blood pressure.(ABSTRACT TRUNCATED AT 250 WORDS)

  20. Hemodynamic changes and pain perception-related anxiety after experiencing an impacted-tooth removal: clinical practice outcome.

    PubMed

    Raocharernporn, Somchart; Boonsiriseth, Kiatanant; Khanijou, Manop; Wongsirichat, Natthamet

    2017-06-01

    Dental fear is usually associated with hemodynamic changes. Fear of pain during the surgical removal of a lower impacted third molar might cause patients anxiety, thereby leading to avoidance of any future dental therapy. This study aimed to determine the effect of experiencing a surgical impacted-tooth removal on the pain perception-related anxiety and hemodynamic status. Twenty-seven healthy patients aged 15-30 years (mean age, 24 years), for whom surgical removal of bilateral lower third molars was advised, were included. This prospective, randomized, controlled, split-mouth study involved operations on both sides of the mandibular arch, with a 1-month washout period in between. Blood pressure and heart rate were measured before the surgical procedure, during and after the injection, preoperatively, and postoperatively. Pain perception was evaluated using a 100-mm visual analog scale during the injection, preoperatively, and postoperatively after the numbness disappeared. Differences in the blood pressure, heart rate, and pain perception between the two appointments were analyzed using the paired t-test. For all statistical analyses, SPSS version 11.5 was used. The mean pain perception values during the injection and preoperatively showed no significant differences between the two appointments (P > 0.05); however, significant differences in the blood pressure and heart rate were noted before the surgical procedure; preoperatively, the blood pressure alone showed a significant difference (P < 0.05). There was a significant decrease in the blood pressure and heart rate preoperatively; hence, experiencing a surgical impacted-tooth removal can reduce the subsequent preoperative anxiety in healthy patients.

  1. Modulation of hemodynamic and vascular filtration changes in diabetic rats by dietary myo-inositol

    SciTech Connect

    Pugliese, G.; Tilton, R.G.; Speedy, A.; Santarelli, E.; Eades, D.M.; Province, M.A.; Kilo, C.; Sherman, W.R.; Williamson, J.R. )

    1990-03-01

    To assess the potential of myo-inositol-supplemented diets to prevent diabetes-induced vascular functional changes, we examined the effects of diets supplemented with 0.5, 1, or 2% myo-inositol on blood flow and vascular filtration function in nondiabetic control rats and rats with streptozocin-induced diabetes (STZ-D). After 1 mo of diabetes and dietary myo-inositol supplementation, (1) 131I-labeled bovine serum albumin (BSA) permeation of vessels was assessed in multiple tissues, (2) glomerular filtration rate (GFR) was estimated as renal plasma clearance of 57Co-labeled EDTA, (3) regional blood flows were measured with 15-microns 85Sr-labeled microspheres, and (4) endogenous albumin and IgG urinary excretion rates were quantified by radial immunodiffusion assay. In STZ-D rats, 131I-BSA tissue clearance increased significantly (2- to 4-fold) in the anterior uvea, choroid-sclera, retina, sciatic nerve, aorta, new granulation tissue, diaphragm, and kidney but was unchanged in skin, forelimb muscle, and heart. myo-Inositol-supplemented diets reduced diabetes-induced increases in 131I-BSA clearance (in a dose-dependent manner) in all tissues; however, only in new granulation tissue and diaphragm did the 2% myo-inositol diet completely normalize vascular albumin permeation. Diabetes-induced increases in GFR and in urinary albumin and IgG excretion were also substantially reduced or normalized by dietary myo-inositol supplements. Increased blood flow in anterior uvea, choroid-sclera, kidney, new granulation tissue, and skeletal muscle in STZ-D rats also was substantially reduced or normalized by the 2% myo-inositol diet. myo-Inositol had minimal if any effects on the above parameters in control rats.

  2. Hemodynamic Signal Changes Accompanying Execution and Imagery of Swallowing in Patients with Dysphagia: A Multiple Single-Case Near-Infrared Spectroscopy Study

    PubMed Central

    Kober, Silvia Erika; Bauernfeind, Günther; Woller, Carina; Sampl, Magdalena; Grieshofer, Peter; Neuper, Christa; Wood, Guilherme

    2015-01-01

    In the present multiple case study, we examined hemodynamic changes in the brain in response to motor execution (ME) and motor imagery (MI) of swallowing in dysphagia patients compared to healthy matched controls using near-infrared spectroscopy (NIRS). Two stroke patients with cerebral lesions in the right hemisphere, two stroke patients with lesions in the brainstem, and two neurologically healthy control subjects actively swallowed saliva (ME) and mentally imagined to swallow saliva (MI) in a randomized order while changes in concentration of oxygenated hemoglobin (oxy-Hb) and deoxygenated hemoglobin (deoxy-Hb) were assessed. In line with recent findings in healthy young adults, MI and ME of swallowing led to the strongest NIRS signal change in the inferior frontal gyrus in stroke patients as well as in healthy elderly. We found differences in the topographical distribution and time course of the hemodynamic response in dependence on lesion location. Dysphagia patients with lesions in the brainstem showed bilateral hemodynamic signal changes in the inferior frontal gyrus during active swallowing comparable to healthy controls. In contrast, dysphagia patients with cerebral lesions in the right hemisphere showed more unilateral activation patterns during swallowing. Furthermore, patients with cerebral lesions showed a prolonged time course of the hemodynamic response during MI and ME of swallowing compared to healthy controls and patients with brainstem lesions. Brain activation patterns associated with ME and MI of swallowing were largely comparable, especially for changes in deoxy-Hb. Hence, the present results provide new evidence regarding timing and topographical distribution of the hemodynamic response during ME and MI of swallowing in dysphagia patients and may have practical impact on future dysphagia treatment. PMID:26217298

  3. Hemodynamic Signal Changes Accompanying Execution and Imagery of Swallowing in Patients with Dysphagia: A Multiple Single-Case Near-Infrared Spectroscopy Study.

    PubMed

    Kober, Silvia Erika; Bauernfeind, Günther; Woller, Carina; Sampl, Magdalena; Grieshofer, Peter; Neuper, Christa; Wood, Guilherme

    2015-01-01

    In the present multiple case study, we examined hemodynamic changes in the brain in response to motor execution (ME) and motor imagery (MI) of swallowing in dysphagia patients compared to healthy matched controls using near-infrared spectroscopy (NIRS). Two stroke patients with cerebral lesions in the right hemisphere, two stroke patients with lesions in the brainstem, and two neurologically healthy control subjects actively swallowed saliva (ME) and mentally imagined to swallow saliva (MI) in a randomized order while changes in concentration of oxygenated hemoglobin (oxy-Hb) and deoxygenated hemoglobin (deoxy-Hb) were assessed. In line with recent findings in healthy young adults, MI and ME of swallowing led to the strongest NIRS signal change in the inferior frontal gyrus in stroke patients as well as in healthy elderly. We found differences in the topographical distribution and time course of the hemodynamic response in dependence on lesion location. Dysphagia patients with lesions in the brainstem showed bilateral hemodynamic signal changes in the inferior frontal gyrus during active swallowing comparable to healthy controls. In contrast, dysphagia patients with cerebral lesions in the right hemisphere showed more unilateral activation patterns during swallowing. Furthermore, patients with cerebral lesions showed a prolonged time course of the hemodynamic response during MI and ME of swallowing compared to healthy controls and patients with brainstem lesions. Brain activation patterns associated with ME and MI of swallowing were largely comparable, especially for changes in deoxy-Hb. Hence, the present results provide new evidence regarding timing and topographical distribution of the hemodynamic response during ME and MI of swallowing in dysphagia patients and may have practical impact on future dysphagia treatment.

  4. Splanchnic Hemodynamics and Intestinal Vascularity in Crohn's Disease: An In Vivo Evaluation Using Doppler and Contrast-Enhanced Ultrasound and Biochemical Parameters.

    PubMed

    Maconi, Giovanni; Asthana, Anil K; Bolzacchini, Elena; Dell'Era, Alessandra; Furfaro, Federica; Bezzio, Cristina; Salvatore, Veronica; Maier, Jeanette A M

    2016-01-01

    Crohn's disease (CD) is characterized by inflammation and angiogenesis of affected bowel. We evaluated the correlation among vascularity of intestinal wall in CD, splanchnic hemodynamics, clinical activity and biochemical parameters of inflammation and angiogenesis. Sixteen patients with ileal CD and 10 healthy controls were investigated by means of Doppler ultrasound of the superior mesenteric artery and color Doppler and contrast-enhanced ultrasound of the ileal wall. In parallel, serum levels of vascular endothelial growth factor, tumor necrosis factor-α (TNF-α) and nitric oxide, before and 30 min after a standard meal, were evaluated. In CD patients, there was a significant post-prandial reduction in the resistance index and pulsatility index of the superior mesenteric artery, associated with increased levels of nitric oxide and decreased amounts of TNF-α. A correlation was observed between vascular endothelial growth factor and contrast-enhanced ultrasound parameters of intestinal wall vascularity (r = 0.63-0.71, p < 0.05) and between these parameters and superior mesenteric artery blood flow after fasting (resistance and pulsatility indexes: r = -0.64 and -0.72, p < 0.05). Our results revealed a post-prandial increase in nitric oxide and decrease in TNF-α in CD patients in vivo. They also confirm the role of vascular endothelial growth factor in angiogenesis and in pathologic vascular remodeling of CD and its effect on splanchnic blood flow.

  5. Real-time magnetic resonance assessment of septal curvature accurately tracks acute hemodynamic changes in pediatric pulmonary hypertension.

    PubMed

    Pandya, Bejal; Quail, Michael A; Steeden, Jennifer A; McKee, Andrea; Odille, Freddy; Taylor, Andrew M; Schulze-Neick, Ingram; Derrick, Graham; Moledina, Shahin; Muthurangu, Vivek

    2014-07-01

    This study assesses the relationship between septal curvature and mean pulmonary artery pressure and indexed pulmonary vascular resistance in children with pulmonary hypertension. We hypothesized that septal curvature could be used to estimate right ventricular afterload and track acute changes in pulmonary hemodynamics. Fifty patients with a median age of 6.7 years (range, 0.45-16.5 years) underwent combined cardiac catheterization and cardiovascular magnetic resonance. The majority had idiopathic pulmonary arterial hypertension (n=30); the remaining patients had pulmonary hypertension associated with repaired congenital heart disease (n=17) or lung disease (n=3). Mean pulmonary artery pressure and pulmonary vascular resistance were acquired at baseline and during vasodilation. Septal curvature was measured using real-time cardiovascular magnetic resonance. There was a strong correlation between mean pulmonary artery pressure and SCmin at baseline and during vasodilator testing (r=-0.81 and -0.85, respectively; P<0.01). A strong linear relationship also existed between pulmonary vascular resistance and minimum septal curvature indexed to cardiac output both at baseline and during vasodilator testing (r=-0.88 and -0.87, respectively; P<0.01). Change in septal curvature metrics moderately correlated with absolute change in mean pulmonary artery pressure and pulmonary vascular resistance, respectively (r=0.58 and -0.74; P<0.01). Septal curvature metrics were able to identify vasoresponders with a sensitivity of 83% (95% confidence interval, 0.36-0.99) and a specificity of 91% (95% confidence interval, 0.77-0.97), using the Sitbon criteria. Idiopathic pulmonary arterial hypertension subgroup analysis revealed 3 responders with ΔSCmin values of 0.523, 0.551, and 0.568. If the middle value of 0.551 is taken as a cutoff, the approximate sensitivity would be 67% and the specificity would be 93%. Septal curvature metrics are able to estimate right ventricular afterload

  6. The ratio of diameters between the target artery and the bypass modifies hemodynamic parameters related to intimal hyperplasia in the distal end-to-side anastomosis.

    PubMed

    Grus, T; Lambert, L; Matěcha, J; Grusová, G; Špaček, M; Mlček, M

    2016-12-13

    Hemodynamics in the distal end-to-side anastomosis is related to early development of intimal hyperplasia and bypass failure. In this study we investigated the effect of diameter ratios between the target artery and the bypass at three different angles of the connection. The pulsatile flow field was visualized using particle image velocimetry in transparent models with three different angles of the connection (25°, 45°, 60°) and the diameter ratio between the bypass and the target artery was 4.6 mm : 6 mm, 6 mm : 6 mm, and 7.5 mm : 6 mm. Six parameters including location and oscillation of the stagnation point, local energy dissipation, wall shear stress (WSS), oscillatory shear index, spatial and temporal gradient of WSS and their distribution in the target artery were calculated from the flow field. In the wider bypass, the stagnation point oscillated in a greater range and was located more proximal to the anastomosis. Energy dissipation was minimal in a wider bypass with a more acute angle. The maximum WSS values were tree times greater in a narrow bypass and concentrated in a smaller circular region at the floor of the anastomosis. The oscillatory shear index increased with wider bypass and more acute angle. The maximum of spatial gradient of WSS concentrated around the floor and toe of the anastomosis and decreased with more acute angle and wider bypass, the temporal gradient of WSS was stretched more towards the side wall. Greater bypass to target vessel ratio and more acute anastomosis angle promote hemodynamics known to reduce formation of intimal hyperplasia.

  7. Associations of Exercise Tolerance With Hemodynamic Parameters for Pulmonary Arterial Hypertension and for Chronic Thromboembolic Pulmonary Hypertension.

    PubMed

    Tsuboi, Yasunori; Tanaka, Hidekazu; Nishio, Ryo; Sawa, Takuma; Terashita, Daisuke; Nakayama, Kazuhiko; Satomi-Kobayashi, Seimi; Sakai, Yoshitada; Emoto, Noriaki; Hirata, Ken-Ichi

    2017-09-01

    hemodynamic assessment by means of RHC for periodic evaluation during followup.

  8. Preventive role of exercise training in autonomic, hemodynamic, and metabolic parameters in rats under high risk of metabolic syndrome development.

    PubMed

    Moraes-Silva, Ivana Cinthya; Mostarda, Cristiano; Moreira, Edson Dias; Silva, Kleiton Augusto Santos; dos Santos, Fernando; de Angelis, Kátia; Farah, Vera de Moura Azevedo; Irigoyen, Maria Claudia

    2013-03-15

    High fructose consumption contributes to metabolic syndrome incidence, whereas exercise training promotes several beneficial adaptations. In this study, we demonstrated the preventive role of exercise training in the metabolic syndrome derangements in a rat model. Wistar rats receiving fructose overload in drinking water (100 g/l) were concomitantly trained on a treadmill (FT) or kept sedentary (F) for 10 wk. Control rats treated with normal water were also submitted to exercise training (CT) or sedentarism (C). Metabolic evaluations consisted of the Lee index and glycemia and insulin tolerance test (kITT). Blood pressure (BP) was directly measured, whereas heart rate (HR) and BP variabilities were evaluated in time and frequency domains. Renal sympathetic nerve activity was also recorded. F rats presented significant alterations compared with all the other groups in insulin resistance (in mg · dl(-1) · min(-1): F: 3.4 ± 0.2; C: 4.7 ± 0.2; CT: 5.0 ± 0.5 FT: 4.6 ± 0.4), mean BP (in mmHG: F: 117 ± 2; C: 100 ± 2; CT: 98 ± 2; FT: 105 ± 2), and Lee index (in g/mm: F = 0.31 ± 0.001; C = 0.29 ± 0.001; CT = 0.27 ± 0.002; FT = 0.28 ± 0.002), confirming the metabolic syndrome diagnosis. Exercise training blunted all these derangements. Additionally, FS group presented autonomic dysfunction in relation to the others, as seen by an ≈ 50% decrease in baroreflex sensitivity and 24% in HR variability, and increases in sympathovagal balance (140%) and in renal sympathetic nerve activity (45%). These impairments were not observed in FT group, as well as in C and CT. Correlation analysis showed that both Lee index and kITT were associated with vagal impairment caused by fructose. Therefore, exercise training plays a preventive role in both autonomic and hemodynamic alterations related to the excessive fructose consumption.

  9. Walking while Performing Working Memory Tasks Changes the Prefrontal Cortex Hemodynamic Activations and Gait Kinematics

    PubMed Central

    Lin, Ming-I B.; Lin, Kuan-Hung

    2016-01-01

    Background: Increasing evidence suggests that walking while performing a concurrent task negatively influences gait performance. However, it remains unclear how higher-level cognitive processes and coordination of limb movements are altered in challenging walking environments. This study investigated the influence of cognitive task complexity and walking road condition on the neutral correlates of executive function and postural control in dual-task walking. Methods: Twenty-four healthy young adults completed a series of overground walks with three walking road conditions (wide, narrow, with obstacles) with and without the concurrent n-back working memory tasks of two complexity levels (1-back and 3-back). Prefrontal brain activation was assessed by functional near-infrared spectroscopy. A three-dimensional motion analysis system was used simultaneously to measure gait performance and lower-extremity kinematics. Repeated measures analysis of variance were performed to examine the differences between the conditions. Results: In comparison with standing still, participants showed lower n-back task accuracy while walking, with the worst performance from the road with obstacles. Spatiotemporal gait parameters, lower-extremity joint movements, and the relative changes in oxygenated hemoglobin (HbO) concentration levels were all significantly different across the task complexity and walking path conditions. While dual-tasking participants were found to flex their hips and knees less, leading to a slower gait speed, longer stride time, shorter step length, and greater gait variability than during normal walking. For narrow-road walking, smaller ankle dorsiflexion and larger hip flexion were observed, along with a reduced gait speed. Obstacle negotiation was mainly characterized by increased gait variability than other conditions. HbO levels appeared to be lower during dual-task walking than normal walking. Compared to wide and obstacle conditions, walking on the narrow

  10. Model estimation of cerebral hemodynamics between blood flow and volume changes: a data-based modeling approach.

    PubMed

    Wei, Hua-Liang; Zheng, Ying; Pan, Yi; Coca, Daniel; Li, Liang-Min; Mayhew, J E W; Billings, Stephen A

    2009-06-01

    It is well known that there is a dynamic relationship between cerebral blood flow (CBF) and cerebral blood volume (CBV). With increasing applications of functional MRI, where the blood oxygen-level-dependent signals are recorded, the understanding and accurate modeling of the hemodynamic relationship between CBF and CBV becomes increasingly important. This study presents an empirical and data-based modeling framework for model identification from CBF and CBV experimental data. It is shown that the relationship between the changes in CBF and CBV can be described using a parsimonious autoregressive with exogenous input model structure. It is observed that neither the ordinary least-squares (LS) method nor the classical total least-squares (TLS) method can produce accurate estimates from the original noisy CBF and CBV data. A regularized total least-squares (RTLS) method is thus introduced and extended to solve such an error-in-the-variables problem. Quantitative results show that the RTLS method works very well on the noisy CBF and CBV data. Finally, a combination of RTLS with a filtering method can lead to a parsimonious but very effective model that can characterize the relationship between the changes in CBF and CBV.

  11. Effects of age-associated regional changes in aortic stiffness on human hemodynamics revealed by computational modeling

    PubMed Central

    Cuomo, Federica; Roccabianca, Sara; Dillon-Murphy, Desmond; Xiao, Nan; Humphrey, Jay D.

    2017-01-01

    Although considered by many as the gold standard clinical measure of arterial stiffness, carotid-to-femoral pulse wave velocity (cf-PWV) averages material and geometric properties over a large portion of the central arterial tree. Given that such properties may evolve differentially as a function of region in cases of hypertension and aging, among other conditions, there is a need to evaluate the potential utility of cf-PWV as an early diagnostic of progressive vascular stiffening. In this paper, we introduce a data-driven fluid-solid-interaction computational model of the human aorta to simulate effects of aging-related changes in regional wall properties (e.g., biaxial material stiffness and wall thickness) and conduit geometry (e.g., vessel caliber, length, and tortuosity) on several metrics of arterial stiffness, including distensibility, augmented pulse pressure, and cyclic changes in stored elastic energy. Using the best available biomechanical data, our results for PWV compare well to findings reported for large population studies while rendering a higher resolution description of evolving local and global metrics of aortic stiffening. Our results reveal similar spatio-temporal trends between stiffness and its surrogate metrics, except PWV, thus indicating a complex dependency of the latter on geometry. Lastly, our analysis highlights the importance of the tethering exerted by external tissues, which was iteratively estimated until hemodynamic simulations recovered typical values of tissue properties, pulse pressure, and PWV for each age group. PMID:28253335

  12. Influence of the site of arterial occlusion on multiple baseline hemodynamic MRI parameters and post-thrombolytic recanalization in acute stroke.

    PubMed

    Derex, L; Hermier, M; Adeleine, P; Pialat, J B; Wiart, M; Berthezène, Y; Froment, J C; Trouillas, P; Nighoghossian, N

    2004-11-01

    In this prospective MRI study, we evaluated the impact of the site of occlusion on multiple baseline perfusion parameters and subsequent recanalization in 49 stroke patients who were given intravenous tissue plasminogen activator (tPA). Pretreatment magnetic resonance angiography (MRA) revealed an arterial occlusion in 47 patients: (1) internal carotid artery (ICA) + M1 middle cerebral artery (MCA) occlusion (n=12); (2) M1 MCA occlusion (n=19); (3) M2 MCA, distal branches of the MCA and anterior cerebral artery (ACA) occlusion (n=16). Patients with ICA occlusion had significantly larger DWI, PWI and mismatch lesion volume on pretreatment MRI compared to patients with other sites of occlusion. The differences in cerebral blood flow (CBF) and peak height were significantly higher in patients with ICA occlusion compared to patients with other sites of occlusion (P=0.03 and P=0.04, respectively). Day 1 MRA showed recanalization in 28 patients (60%). The rate of recanalization was significantly different depending on the site of occlusion: 33% in ICA + M1 MCA occlusion, 63% in M1 MCA occlusion and 81% in either M2 MCA, distal branches of the MCA or ACA occlusion (P=0.002). Our data suggest that CBF and peak height are the most relevant MRI parameters to assess the severity of hemodynamic impairment in regard to the site of occlusion.

  13. Acute Hemodynamic Changes After Rapid Intravenous Bolus Dosing of Dexmedetomidine in Pediatric Heart Transplant Patients Undergoing Routine Cardiac Catheterization

    PubMed Central

    Jooste, EH; Muhly, WT; Ibinson, JW; Suresh, T; Damian, D; Phadke, A; Callahan, P; Miller, S; Feingold, B; Lichtenstein, SE; Cain, JG; Chrysostomou, C; Davis, PJ

    2011-01-01

    in pressures was more pronounced in the systemic system than in the pulmonary system. In the systemic system there was a larger percent increase in the diastolic pressures than the systolic pressures. Cardiac output, CVP and pulmonary vascular resistance did not change significantly. HR decreased at 1 min for both doses and was, within the 0.5 mcg/kg group, the only hemodynamic variable still changed from baseline at the 5 min time point Conclusion Rapid IV bolus administration of dexmedetomidine in this small sample of children having undergone heart transplants was clinically well tolerated, although it resulted in a transient but significant increase in systemic and pulmonary pressure and a decrease in HR. In the systemic system there is a larger percent increase in the diastolic pressures than the systolic pressures, and furthermore these transient increases in pressures were more pronounced in the systemic system than in the pulmonary system. PMID:21059743

  14. Changes in platelet, coagulation, and fibrinolytic activities in mitral stenosis after percutaneous mitral valvotomy: role of hemodynamic changes and systemic inflammation.

    PubMed

    Hasan-Ali, Hosam; Mosad, Eman

    2015-05-01

    Markers of platelet activity (P-selectin), fibrinolysis (d-dimer), thrombin activity (prothrombin fragments 1, 2 [PF1,2] and thrombin-antithrombin III complex [TAT]), and inflammation (interleukin 1β [IL-1β]) were measured in 65 patients with mitral stenosis (MS) before and 2 weeks after percutaneous mitral valvotomy (PMV) and in 23 controls. All markers were significantly higher than the control and significantly decreased after PMV. P-selectin change correlated with the changes in left atrial diameter (LAD), pulmonary artery systolic pressure (PASP), and IL-1β. d-Dimer change had similar correlations, LAD, PASP, and IL-1β. The PF1,2 change correlated with the change in IL-1β. The TAT change correlated with the changes in LAD. The IL-1β change correlated with the changes in PASP. In conclusion, MS is associated with heightened inflammatory, platelet, thrombin, and fibrinolytic activities that decrease after PMV. Altered hemodynamics and reduced inflammatory activity might have a possible role in these changes.

  15. [Effects of oral fluid resuscitation with pyruvate-oral rehydration solution on the hemodynamic parameters and organ functions during shock stage in dogs with a 50% total body surface area full thickness burn].

    PubMed

    Meng, Xiangxi; Li, Juan; Bai, Xiaodong; Hu, Sen; Zhou, Fangqiang

    2014-06-01

    To study the effect of oral fluid resuscitation with pyruvate sodium-glucose-electrolyte solution (PGES) on hemodynamics, organ functions and mortalities during shock stage in dogs with burn. In comparison of oral pyruvate sodium-glucose-electrolyte solution (PGES) with NaHCO₃-glucose-electrolyte solution (HGES), beagle dogs with intubation of the carotid artery, jugular vein and jejunum for 24 hours were subjected to a 50% total body surface area (TBSA) burn, and were divided into three groups: pure burn without fluid resuscitation (NR, n = 8), and two oral fluid resuscitation (each n = 10), in which dogs were given with Pry-GES (OP) or NaHCO₃-GES (OH) according to Parkland formula. The hemodynamic and organ functions were measured serially before burn and 2, 6, 8, 12 and 24 hours after burn at no anaesthesia state A. Twenty-four hours mortality rate following burn was also recorded. Two hours after burn, the mean arterial pressure of NR, OH and OP group was (45 ± 8), (57 ± 8) and (80 ± 9) mmHg (1 mmHg = 0.133 kPa) respectively, which were significantly reduced (t = 16.967, 14.595 and 10.100, all P < 0.05) compared with those before injury ((42 ± 6), (144 ± 6) and (142 ± 6) mmHg respectively), the change of cardiac output, dp/dtmax of left ventricular contractility and intestinal mucosal blood flow had the same trend as the mean arterial pressure. The systemic vascular resistance and organ parameters (Cr, CK-MB, ALT and DAO) in all groups increased obviously (t = -46.894--2.465, all P < 0.05). All measurements of NR group kept worsening, and all died within 24 hours after burn; while those of two oral resuscitation groups had improved gradually (F = 0.001-1.600, all P < 0.05), OP group was significantly superior to OH group (F = 0.013-0.466, P < 0.05). At 24 hours after burn, 6 (6/10) survived in OP group, 4 (4/10) in OH group and 0 (0/8) in NR group. The Pyr-GES may be superior to the standard NaHCO₃-GES in the improvement of hemodynamics and organ

  16. Hemodynamic changes associated with spinal and general anesthesia for hip fracture surgery in severe ASA III elderly population: a pilot trial.

    PubMed

    Messina, A; Frassanito, L; Colombo, D; Vergari, A; Draisci, G; Della Corte, F; Antonelli, M

    2013-09-01

    Patients affected by hip fracture (HF) have high risk of perioperative complications. Despite regional anesthesia is widely used, hypotension is common and increases the risk of myocardial ischemia. The aim of this work was to study hemodynamic changes following spinal (SA) and general (GA) anesthesia in this selected population of patients. Twenty patients over 70 years, ASA III, scheduled for HF repair were randomized to receive SA or general anesthesia GA. Hemodynamic responses to SA and GA were analyzed trough LiDCO™plus monitor (LiDCO Ltd., Cambridge, UK). SA provided a more stable hemodynamic profile. SA group received less interventions to keep mean arterial pressure (MAP) within limits. GA group had intraoperative cardiac index (CI), stroke volume index (SVI) and MAP significantly lower than baseline. Despite both groups experienced hypotension after the induction, MAP reduction in SA group was primarily due to systemic vascular resistance index (SVRI) decline, whereas hypotension in GA group was primarily due to a reduction in SVI and CI. The coefficient of variation (CV) was significantly higher in GA group for CI, SVI, MAP and heart rate (HR) within one hour analysis comparing to SA group. SA group had an higher CV for SVRI. SA in the elderly population with hip fracture provides a more stable hemodynamic profile requiring less intervention to keep MAP close to baseline value. Hypotension was common in SA and GA after induction and within intraoperative period. A larger randomized clinical study should be performed to confirm these preliminary data.

  17. Relationship between gated myocardial perfusion SPECT findings and hemodynamic, electrocardiographic, and heart rate changes after Dipyridamole infusion.

    PubMed

    Gholoobi, Arash; Ayati, Narjess; Baghyari, Alireza; Mouhebati, Mohsen; Atar, Baharak; Dabbagh Kakhki, Vahid Reza

    2017-02-01

    After dipyridamole infusion, electrocardiographic (ECG), blood pressure and heart rate (HR) changes were seen. We tried to investigate whether there is a relationship between hemodynamic, ECG and HR changes after dipyridamole infusion and gated myocardial perfusion SPECT findings. We studied 206 consecutive patients which underwent a 2-day protocol Dipyridamole Stress/Rest Tc99m-Sestamibi gated myocardial perfusion SPECT. Systolic blood pressure (SBP), diastolic blood pressure (DBP), HR and ECG were recorded. HR was mildly increased while SBP and DBP were mildly decreased after Dipyridamole infusion. There was only statistically significant difference between ECG changes as well as transient ischemic dilation (TID) ratio between normal scans and scans with ischemia (P = 0.02 and P = 0.01 respectively). There was correlation between these variables and summed stress score (SSS) and summed difference score (SDS). Patients with ischemia in their scans, 44.3% had ST depression after Dipyridamole infusion. Also ST depression most frequently was seen in patients with left anterior descending artery disease. From patients with abnormal scan + ST depression after Dipyridamole infusion (33 patient), 27 patient (81.81%) had ischemia. There was an association between TID ratio as well as ECG changes after Dipyridamole infusion and SSS, SDS and coronary artery territory abnormality. Difference between calculated left ventricular ejection fraction using stress and rest images had significant correlation with SSS and SDS. ST depression after Dipyridamole infusion and TID ratio had association with ischemia, SSS and SDS. So in equivocal Gated SPECT findings, they could be very useful for interpretation.

  18. Combined inhibition of complement C5 and CD14 markedly attenuates inflammation, thrombogenicity, and hemodynamic changes in porcine sepsis.

    PubMed

    Barratt-Due, Andreas; Thorgersen, Ebbe B; Egge, Kjetil; Pischke, Søren; Sokolov, Andrey; Hellerud, Bernt C; Lindstad, Julie K; Pharo, Anne; Bongoni, Anjan K; Rieben, Robert; Nunn, Miles; Scott, Helge; Mollnes, Tom E

    2013-07-15

    Complement and the TLR family constitute two important branches of innate immunity. We previously showed attenuating effects on inflammation and thromogenicity by inhibiting the TLR coreceptor CD14 in porcine sepsis. In the present study, we explored the effect of the C5 and leukotriene B4 inhibitor Ornithodoros moubata complement inhibitor (OmCI; also known as coversin) alone and combined with anti-CD14 on the early inflammatory, hemostatic, and hemodynamic responses in porcine Escherichia coli-induced sepsis. Pigs were randomly allocated to negative controls (n = 6), positive controls (n = 8), intervention with OmCI (n = 8), or with OmCI and anti-CD14 (n = 8). OmCI ablated C5 activation and formation of the terminal complement complex and significantly decreased leukotriene B4 levels in septic pigs. Granulocyte tissue factor expression, formation of thrombin-antithrombin complexes (p < 0.001), and formation of TNF-α and IL-6 (p < 0.05) were efficiently inhibited by OmCI alone and abolished or strongly attenuated by the combination of OmCI and anti-CD14 (p < 0.001 for all). Additionally, the combined therapy attenuated the formation of plasminogen activator inhibitor-1 (p < 0.05), IL-1β, and IL-8, increased the formation of IL-10, and abolished the expression of wCD11R3 (CD11b) and the fall in neutrophil cell count (p < 0.001 for all). Finally, OmCI combined with anti-CD14 delayed increases in heart rate by 60 min (p < 0.05) and mean pulmonary artery pressure by 30 min (p < 0.01). Ex vivo studies confirmed the additional effect of combining anti-CD14 with OmCI. In conclusion, upstream inhibition of the key innate immunity molecules, C5 and CD14, is a potential broad-acting treatment regimen in sepsis as it efficiently attenuated inflammation and thrombogenicity and delayed hemodynamic changes.

  19. Effect of maintenance oral theophylline on dipyridamole-thallium-201 myocardial imaging using SPECT and dipyridamole-induced hemodynamic changes

    SciTech Connect

    Daley, P.J.; Mahn, T.H.; Zielonka, J.S.; Krubsack, A.J.; Akhtar, R.; Bamrah, V.S.

    1988-06-01

    To evaluate the effect of maintenance oral theophylline therapy on the diagnostic efficacy of dipyridamole-thallium-201 single photon emission computed tomography (SPECT) imaging for coronary artery disease, dipyridamole-thallium-201 SPECT imaging was performed in eight men with documented coronary artery disease before initiation of theophylline treatment and repeated while these patients were receiving therapeutic doses of oral theophylline. Before theophylline treatment, intravenous dipyridamole caused a significant increase in heart rate, decrease in blood pressure, angina in seven of eight patients, and ST segment depression in four of eight patients. While they were being treated with theophylline, none of the patients had angina or ST segment depression, and there were no hemodynamic changes with intravenous dipyridamole. Before theophylline treatment, dipyridamole-thallium-201 SPECT imaging showed reversible perfusion defects in myocardial segments supplied by stenotic coronary arteries. With theophylline treatment, dipyridamole-thallium-201 SPECT showed total absence of reversible perfusion defects. Treatment with theophylline markedly reduced the diagnostic accuracy of dipyridamole-thallium-201 imaging for coronary artery disease.

  20. Circulating Elastin Fragments Are Not Affected by Hepatic, Renal and Hemodynamic Changes, But Reflect Survival in Cirrhosis with TIPS.

    PubMed

    Nielsen, M J; Lehmann, J; Leeming, D J; Schierwagen, R; Klein, S; Jansen, C; Strassburg, C P; Bendtsen, F; Møller, S; Sauerbruch, T; Karsdal, M A; Krag, A; Trebicka, J

    2015-11-01

    Progressive fibrosis increases hepatic resistance and causes portal hypertension with complications. During progressive fibrosis remodeling and deposition of collagens and elastin occur. Elastin remodeling is crucially involved in fibrosis progression in animal models and human data. This study investigated the association of circulating elastin with the clinical outcome in cirrhotic patients with severe portal hypertension receiving transjugular intrahepatic porto-systemic shunt (TIPS). We analyzed portal and hepatic venous samples of 110 cirrhotic patients obtained at TIPS insertion and 2 weeks later. The circulating levels of elastin fragments (ELM) were determined using specific monoclonal ELISA. The relationship of ELM with clinical short-time follow-up and long-term outcome was investigated. Circulating levels of ELM showed a gradient across the liver before TIPS with higher levels in the hepatic vein. Interestingly, the circulating ELM levels remained unchanged after TIPS. The circulating levels of ELM in portal and hepatic veins correlated with platelet counts and inversely with serum sodium. Hepatic venous levels of ELM were higher in CHILD C compared to CHILD A and B and were associated with the presence of ascites. Patients with high levels of ELM in the hepatic veins before TIPS showed poorer survival. In multivariate analysis ELM levels in the hepatic veins and MELD were independent predictors of mortality in these patients. This study demonstrated that circulating levels of ELM are not associated with hemodynamic changes, but might reflect fibrosis remodeling and predict survival in patients with severe portal hypertension receiving TIPS independently of MELD.

  1. [Changes of the hemodynamics, heart structure and functional state in patients with reactive arthritis].

    PubMed

    Spas'ka, H O

    2014-01-01

    Our investigation showed for the patients with reactive arthritis typical is hyperkinetic type of haemodynamic, and also structural changes of the heart which manifestate by interventricular partition's thickness as a result of inflammatory edema and it's valve consolidation frequently whithout expressed blood regurgitation, and diastolic dysfunction's development of the left and right heart ventricles in hypertrophic type with disorders of their active relaxation and growth their chamber's rigidity. These changes, probably, evidence about development of the inflammatory cardiopathy in these patients and can be preconditions of the heart failure.

  2. Correlation between cerebral hemodynamic and perfusion pressure changes in non-human primates

    NASA Astrophysics Data System (ADS)

    Ruesch, A.; Smith, M. A.; Wollstein, G.; Sigal, I. A.; Nelson, S.; Kainerstorfer, J. M.

    2017-02-01

    The mechanism that maintains a stable blood flow in the brain despite changes in cerebral perfusion pressure (CPP), and therefore guaranties a constant supply of oxygen and nutrients to the neurons, is known as cerebral auto-regulation (CA). In a certain range of CPP, blood flow is mediated by a vasomotor adjustment in vascular resistance through dilation of blood vessels. CA is known to be impaired in diseases like traumatic brain injury, Parkinson's disease, stroke, hydrocephalus and others. If CA is impaired, blood flow and pressure changes are coupled and thee oxygen supply might be unstable. Lassen's blood flow auto-regulation curve describes this mechanism, where a plateau of stable blood flow in a specific range of CPP corresponds to intact auto-regulation. Knowing the limits of this plateau and maintaining CPP within these limits can improve patient outcome. Since CPP is influenced by both intracranial pressure and arterial blood pressure, long term changes in either can lead to auto-regulation impairment. Non-invasive methods for monitoring blood flow auto-regulation are therefore needed. We propose too use Near infrared spectroscopy (NIRS) too fill this need. NIRS is an optical technique, which measures microvascular changes in cerebral hemoglobin concentration. We performed experiments on non-human primates during exsanguination to demonstrate that thee limits of blood flow auto-regulation can be accessed with NIRS.

  3. [Changes in the cerebral hemodynamics during Rohypnol anesthesia in neurosurgical patients].

    PubMed

    Gribkov, A V; Bakunin, L M; Rufova, N Iu

    1994-01-01

    Intracranial pressure, cerebral perfusion pressure, and intracerebral blood volume changes were observed in 43 patients with volumetric intracranial processes (intracranial hematomas, tumors) during general rohypnol anesthesia. Intracranial and cerebral perfusion pressures were found to correlate with intracerebral blood volume. Rohypnol anesthesia decreased intracranial pressure by 25% due to reduced arterial blood influx into the head, mechanisms responsible for autoregulation of cerebral circulation being intact.

  4. A pilot study of systolic dyssynchrony index by real time three-dimensional echocardiography and Doppler tissue imaging parameters predicting the hemodynamic response to biventricular pacing in the early postoperative period after cardiac surgery.

    PubMed

    Straka, Frantisek; Pirk, Jan; Pindak, Marian; Marek, Tomas; Schornik, David; Cihak, Robert; Skibova, Jelena

    2012-08-01

    To evaluate systolic dyssynchrony index (SDI) measured by real time three-dimensional echocardiography (RT3DE) and Doppler tissue imaging (DTI) dyssynchrony parameters in predicting the hemodynamic response to biventricular (BIV) pacing in the early postoperative period after cardiac surgery. To compare right ventricular (RV) and BIV pacing using invasively measured hemodynamic values. A prospective randomized clinical study enrolling 11 patients with ischemic heart disease, concomitant valvular heart disease, and left ventricular ejection fraction (LVEF) ≤ 35% comparing preoperative SDI by RT3DE and DTI LV dyssynchrony parameters to hemodynamic values obtained during RV or BIV sequential (DDD) epicardial pacing in the first 72 hours after cardiac surgery. BIV pacing produced a statistically significant higher cardiac output (CO) (6.27 ± 1.55 L/min) and cardiac index (CI) (3.44 ± 0.93 L/min per m(2) ) than RV pacing (CO 5.44 ± 0.97 L/min, CI 3.03 ± 0.83 L/min per m(2) , P < 0.05). We found a statistically moderate correlation between preoperative SDI by RT3DE and CO (r = 0.596, P < 0.05) and a nonsignificant correlation to CI (r = 0.535, P < 0.10) during BIV pacing. No correlation was observed between DTI dyssynchrony parameters and measured hemodynamic values. BIV pacing reduced the ICU stay and inotropic support requirements of patients after heart surgery. SDI measured preoperatively using RT3DE can predict CO during BIV pacing in the early postoperative period after cardiac surgery. BIV pacing is more hemodynamically effective than RV pacing in patients with LV dysfunction after coronary artery bypass grafting with or without a valve procedure. © 2012, Wiley Periodicals, Inc.

  5. Clinical practice parameters for hemodynamic support of pediatric and neonatal septic shock: 2007 update from the American College of Critical Care Medicine

    PubMed Central

    Brierley, Joe; Carcillo, Joseph A.; Choong, Karen; Cornell, Tim; DeCaen, Allan; Deymann, Andreas; Doctor, Allan; Davis, Alan; Duff, John; Dugas, Marc-Andre; Duncan, Alan; Evans, Barry; Feldman, Jonathan; Felmet, Kathryn; Fisher, Gene; Frankel, Lorry; Jeffries, Howard; Greenwald, Bruce; Gutierrez, Juan; Hall, Mark; Han, Yong Y.; Hanson, James; Hazelzet, Jan; Hernan, Lynn; Kiff, Jane; Kissoon, Niranjan; Kon, Alexander; Irazusta, Jose; Lin, John; Lorts, Angie; Mariscalco, Michelle; Mehta, Renuka; Nadel, Simon; Nguyen, Trung; Nicholson, Carol; Peters, Mark; Okhuysen-Cawley, Regina; Poulton, Tom; Relves, Monica; Rodriguez, Agustin; Rozenfeld, Ranna; Schnitzler, Eduardo; Shanley, Tom; Skache, Sara; Skippen, Peter; Torres, Adalberto; von Dessauer, Bettina; Weingarten, Jacki; Yeh, Timothy; Zaritsky, Arno; Stojadinovic, Bonnie; Zimmerman, Jerry; Zuckerberg, Aaron

    2013-01-01

    Background The Institute of Medicine calls for the use of clinical guidelines and practice parameters to promote “best practices” and to improve patient outcomes. Objective 2007 update of the 2002 American College of Critical Care Medicine Clinical Guidelines for Hemodynamic Support of Neonates and Children with Septic Shock. Participants Society of Critical Care Medicine members with special interest in neonatal and pediatric septic shock were identified from general solicitation at the Society of Critical Care Medicine Educational and Scientific Symposia (2001–2006). Methods The Pubmed/MEDLINE literature database (1966–2006) was searched using the keywords and phrases: sepsis, septicemia, septic shock, endotoxemia, persistent pulmonary hypertension, nitric oxide, extracorporeal membrane oxygenation (ECMO), and American College of Critical Care Medicine guidelines. Best practice centers that reported best outcomes were identified and their practices examined as models of care. Using a modified Delphi method, 30 experts graded new literature. Over 30 additional experts then reviewed the updated recommendations. The document was subsequently modified until there was greater than 90% expert consensus. Results The 2002 guidelines were widely disseminated, translated into Spanish and Portuguese, and incorporated into Society of Critical Care Medicine and AHA sanctioned recommendations. Centers that implemented the 2002 guidelines reported best practice outcomes (hospital mortality 1%–3% in previously healthy, and 7%– 10% in chronically ill children). Early use of 2002 guidelines was associated with improved outcome in the community hospital emergency department (number needed to treat = 3.3) and tertiary pediatric intensive care setting (number needed to treat = 3.6); every hour that went by without guideline adherence was associated with a 1.4-fold increased mortality risk. The updated 2007 guidelines continue to recognize an increased likelihood that

  6. Effects of Sacubitril/Valsartan Versus Olmesartan on Central Hemodynamics in the Elderly With Systolic Hypertension: The PARAMETER Study.

    PubMed

    Williams, Bryan; Cockcroft, John R; Kario, Kazuomi; Zappe, Dion H; Brunel, Patrick C; Wang, Qian; Guo, Weinong

    2017-03-01

    Effective treatment of systolic hypertension in elderly patients remains a major therapeutic challenge. A multicenter, double-blind, randomized controlled trial with sacubitril/valsartan (LCZ696), a first-in-class angiotensin receptor neprilysin inhibitor, was conducted to determine its effects versus olmesartan (angiotensin receptor blocker) on central aortic pressures, in elderly patients (aged ≥60 years) with systolic hypertension and pulse pressure >60 mm Hg, indicative of arterial stiffness. Patients (n=454; mean age, 67.7 years; mean seated systolic blood pressure, 158.6 mm Hg; mean seated pulse pressure, 69.7 mm Hg) were randomized to receive once-daily sacubitril/valsartan 200 mg or olmesartan 20 mg, force titrated to double the initial doses after 4 weeks, before primary assessment at 12 weeks. The study extended double-blind treatment for 12 to 52 weeks, during which amlodipine (2.5-5 mg) and subsequently hydrochlorothiazide (6.25-25 mg) were added-on for patients not achieving blood pressure target (<140/90). At week 12, sacubitril/valsartan reduced central aortic systolic pressure (primary assessment) greater than olmesartan by -3.7 mm Hg (P=0.010), further corroborated by secondary assessments at week 12 (central aortic pulse pressure, -2.4 mm Hg, P<0.012; mean 24-hour ambulatory brachial systolic blood pressure and central aortic systolic pressure, -4.1 mm Hg and -3.6 mm Hg, respectively, both P<0.001). Differences in 24-hour ambulatory pressures were pronounced during sleep. After 52 weeks, blood pressure parameters were similar between treatments (P<0.002); however, more patients required add-on antihypertensive therapy with olmesartan (47%) versus sacubitril/valsartan (32%; P<0.002). Both treatments were equally well tolerated. The PARAMETER study (Prospective Comparison of Angiotensin Receptor Neprilysin Inhibitor With Angiotensin Receptor Blocker Measuring Arterial Stiffness in the Elderly), for the first time, demonstrated

  7. Evaluation of cerebral hemodynamic changes by Tc-99m HMPAO SPECT after radiosurgery of small arteriovenous malformations (AVM)

    SciTech Connect

    Liu, R.S.; Yeh, S.H.; Pan, H.C.

    1994-05-01

    Treatment of small AVMs (<3 cm) by stereotaxic radio-surgery using gamma unit has been a promising noninvasive method. However, cerebral hemodynamic changes after gamma unit treatment is obscure. This study assessed the effect of radiosurgery on the regional cerebral blood flow (rCBF) in treatment of small AVMs. Nine patients (pts) with small AVMs were imaged with SPECT using Tc-99m HMPAO prior to stereotactic radio-surgery. The pts were treated with a Leskell gamma unit with doses of radiation in the range of 36 Gy to 44 Gy at target center. All pts underwent HMPAO SPECT scans about 3 months after radiosurgery. Pts were also studied with CT/MR scans. Pre treatment HMPAO SPECT showed decreased rCBF in the regions of nidi of AVMs of all pts and in the adjacent zones in 2 pts. Increased rCBF surrounding the nidus was noted in 2 AVMs. After treatment, rCBF of 2 pts returned to normal, 6 pts showed much improvement of rCBF and 1 remained no change. No more perfusion abnormalities were seen in the adjacent zones of all AVMs after radiosurgery. Cross cerebellar diaschisis noted in one case also disappeared after radiosurgery. Post treatment CT/MR scans showed slightly decrease in size of AVMs in 6 pts. All pts had great improvement after treatment. Normalization of rCBF correlated well with improvements in the neurological symptoms. In conclusion, comparison of pre and post treatment Tc-99m HMPAO SPECT scans were useful in evaluating the effectiveness of gamma unit radiosurgery on small AVMs.

  8. Transcranial magnetic stimulation elicits coupled neural and hemodynamic consequences.

    PubMed

    Allen, Elena A; Pasley, Brian N; Duong, Thang; Freeman, Ralph D

    2007-09-28

    Transcranial magnetic stimulation (TMS) is an increasingly common technique used to selectively modify neural processing. However, application of TMS is limited by uncertainty concerning its physiological effects. We applied TMS to the cat visual cortex and evaluated the neural and hemodynamic consequences. Short TMS pulse trains elicited initial activation (approximately 1 minute) and prolonged suppression (5 to 10 minutes) of neural responses. Furthermore, TMS disrupted the temporal structure of activity by altering phase relationships between neural signals. Despite the complexity of this response, neural changes were faithfully reflected in hemodynamic signals; quantitative coupling was present over a range of stimulation parameters. These results demonstrate long-lasting neural responses to TMS and support the use of hemodynamic-based neuroimaging to effectively monitor these changes over time.

  9. The PhysioFlow Thoracic Impedancemeter Is Not Valid for the Measurements of Cardiac Hemodynamic Parameters in Chronic Anemic Patients

    PubMed Central

    Bogui, Pascal; Balayssac-Siransy, Edwige; Connes, Philippe; Tuo, Nalourgo; Ouattara, Soualiho; Pichon, Aurélien; Dah, Cyrille Serges

    2013-01-01

    The aim of the present study was to test the validity of the transthoracic electrical bioimpedance method PhysioFlow® to measure stroke volume in patients with chronic anemia. Stroke volume index (SVI), as well as cardiac index (CI) obtained by transthoracic electrical bioimpedance method and doppler echocardiography were compared in healthy subjects (n = 25) and patients with chronic anemia (i.e. mainly with sickle cell anemia; n = 32), at rest. While doppler echocardiography was able to detect difference in SVI between the two populations, the Physioflow® failed to detect any difference. Bland & Altman analyses have demonstrated no interchangeability between the two methods to assess CI and SVI in anemic patients and healthy subjects. While doppler echocardiography displayed a good concordance for SVI results with those obtained in the literature for anemic patients, the Physioflow® did not. Finally, in contrast to doppler echocardiography: 1) the CI obtained with the Physioflow® was not correlated with the hemoglobin level and 2) the stroke volume determined by the Physioflow® was highly influenced by body surface area. In conclusion, our findings indicate that the Physioflow® device is inaccurate for the measurement of SVI and CI in patients with chronic anemia and has a poor accuracy for the measurement of these parameters in African healthy subjects. PMID:24167637

  10. The PhysioFlow thoracic impedancemeter is not valid for the measurements of cardiac hemodynamic parameters in chronic anemic patients.

    PubMed

    Bogui, Pascal; Balayssac-Siransy, Edwige; Connes, Philippe; Tuo, Nalourgo; Ouattara, Soualiho; Pichon, Aurélien; Dah, Cyrille Serges

    2013-01-01

    The aim of the present study was to test the validity of the transthoracic electrical bioimpedance method PhysioFlow® to measure stroke volume in patients with chronic anemia. Stroke volume index (SVI), as well as cardiac index (CI) obtained by transthoracic electrical bioimpedance method and doppler echocardiography were compared in healthy subjects (n = 25) and patients with chronic anemia (i.e. mainly with sickle cell anemia; n = 32), at rest. While doppler echocardiography was able to detect difference in SVI between the two populations, the Physioflow® failed to detect any difference. Bland & Altman analyses have demonstrated no interchangeability between the two methods to assess CI and SVI in anemic patients and healthy subjects. While doppler echocardiography displayed a good concordance for SVI results with those obtained in the literature for anemic patients, the Physioflow® did not. Finally, in contrast to doppler echocardiography: 1) the CI obtained with the Physioflow® was not correlated with the hemoglobin level and 2) the stroke volume determined by the Physioflow® was highly influenced by body surface area. In conclusion, our findings indicate that the Physioflow® device is inaccurate for the measurement of SVI and CI in patients with chronic anemia and has a poor accuracy for the measurement of these parameters in African healthy subjects.

  11. Changes in renal hemodynamics and renin release caused by increased plasma oncotic pressure.

    PubMed

    Hall, J E; Guyton, A C

    1976-11-01

    The effect of increased plasma oncotic pressure on renal blood flow (RBF), glomerular filtration rate (GFR), electrolyte excretion, and renin secretion rate (RSR) was studied in dogs anesthetized with sodium pentobarbital. Renal artery infusions of hyperoncotic dextran or human serum albumin raised renal venous colloid osmotic pressure an average of 7.3 and 10.1 mmHg, respectively, and caused small but consistent increases in RBF, large increases in RSR, marked decreases in urine flow rate and electrolyte excretion, with either no change or small decreases in GFR, and no change in renal artery pressure. Renal vasodilation was confined primarily to afferent arterioles and was not measureable until approximately 45 s after the start of infusions. The renal responses to increased plasma oncotic pressure appeared to be an autoregulatory phenomenon, consistent with a tubular mechanism dependent on an altered distal tubular fluid flow and/or composition. The increased renin release during increased plasma oncotic pressure is not compatible with a renal baroreceptor mechanism that responds to decreases in afferent arteriolar pressure because calculated glomerular pressure increased during albumin and dextran infusions.

  12. Association of autism tendency and hemodynamic changes in the prefrontal cortex during facial expression stimuli measured by multi-channel near-infrared spectroscopy.

    PubMed

    Hosokawa, Mai; Nakadoi, Yoshihiro; Watanabe, Yukina; Sumitani, Satsuki; Ohmori, Tetsuro

    2015-03-01

    The aim of this study is to examine the hemodynamic changes induced by the cognitive process of facial expression by using multi-channel near-infrared spectroscopy in healthy subjects with varying degrees of autism tendency. Subjects were 38 volunteers, 20 men and 18 women. Autism tendency was measured by the Autism Spectrum Quotient. The hemodynamic changes in the prefrontal cortex were measured by 24-channel near-infrared spectroscopy system, while subjects were asked to judge their own emotional response to standardized pictures of eight kinds of facial expressions on a computer screen. There were significant negative correlations between Autism Spectrum Quotient scores and accuracy of fearful expression recognition as well as increases in the concentration of oxygenated hemoglobin in response to four kinds of emotional faces (fear, contempt, sadness and disgust). Our findings suggest that the greater tendency to autism that subjects have, the more difficulty they have in recognizing a fearful expression and the less hemodynamic change in the prefrontal cortex they show in response to negative facial expressions. © 2014 The Authors. Psychiatry and Clinical Neurosciences © 2014 Japanese Society of Psychiatry and Neurology.

  13. Randomized Controlled Trial of High-Volume Energy Drink Versus Caffeine Consumption on ECG and Hemodynamic Parameters.

    PubMed

    Fletcher, Emily A; Lacey, Carolyn S; Aaron, Melenie; Kolasa, Mark; Occiano, Andrew; Shah, Sachin A

    2017-04-26

    Caffeine in doses <400 mg is typically not considered arrhythmogenic, but little is known about the additional ingredients in energy drinks. We evaluated the ECG and blood pressure (BP) effects of high-volume energy drink consumption compared with caffeine alone. This was a randomized, double-blind, controlled, crossover study in 18 young, healthy volunteers. Participants consumed either 946 mL (32 ounces) of energy drink or caffeinated control drink, both of which contained 320 mg of caffeine, separated by a 6-day washout period. ECG, peripheral BP, and central BP measurements were obtained at baseline and 1, 2, 4, 6, and 24 hours post study drink consumption. The time-matched, baseline-adjusted changes were compared. The change in corrected QT interval from baseline in the energy drink arm was significantly higher than the caffeine arm at 2 hours (0.44±18.4 ms versus -10.4±14.8 ms, respectively; P=0.02). The QTc changes were not different at other time points. While both the energy drink and caffeine arms raised systolic BP in a similar fashion initially, the systolic BP was significantly higher at 6 hours when compared with the caffeine arm (4.72±4.67 mm Hg versus 0.83±6.09 mm Hg, respectively; P=0.01). Heart rate, diastolic BP, central systolic BP, and central diastolic BP showed no evidence of a difference between groups at any time point. Post energy drink, augmentation index was lower at 6 hours. The corrected QT interval and systolic BP were significantly higher post high-volume energy drink consumption when compared with caffeine alone. Larger clinical trials validating these findings and evaluation of noncaffeine ingredients within energy drinks are warranted. URL: http://www.clinicaltrials.gov. Unique identifier: NCT02023723. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

  14. Developmental Changes in Hemodynamic Responses and Cardiovagal Modulation during Isometric Handgrip Exercise

    PubMed Central

    Goulopoulou, Styliani; Fernhall, Bo; Kanaley, Jill A.

    2010-01-01

    The purpose of this study was to examine differences in pressor response and cardiovagal modulation during isometric handgrip exercise (IHG) between children and adults. Beat-to-beat heart rate (HR) and blood pressure were measured in 23 prepubertal children and 23 adults at baseline and during IHG. Cardiovagal modulation was quantified by analysis of HR variability. Mean arterial pressure responses to IHG were greater in adults compared to children (P < .05) whereas there were no group differences in HR responses (P > .05). Children had a greater reduction in cardiovagal modulation in response to IHG compared to adults (P < .05). Changes in mean arterial pressure during IHG were correlated with baseline cardiovagal modulation and force produced during isometric contraction (P < .05). In conclusion, differences in pressor reflex response between children and adults cannot be solely explained by differences in autonomic modulation and appear to be associated with factors contributing to the force produced during isometric contraction. PMID:20862202

  15. Influence of the prone position on a stretcher for pregnant women on maternal and fetal hemodynamic parameters and comfort in pregnancy

    PubMed Central

    Oliveira, Claudia; Lopes, Marco Antonio Borges; Rodrigues, Agatha Sacramento; Zugaib, Marcelo; Francisco, Rossana Pulcineli Vieira

    2017-01-01

    OBJECTIVES: To analyze the influence of lying in prone position on a specially designed stretcher on the maternal-fetal hemodynamic parameters and comfort of pregnant women. METHODS: A randomized, controlled trial with 33 pregnant women divided into 2 groups: pregnant group sequence 1 and pregnant group sequence 2. The order of positions used in sequence 1 was Fowler’s position, prone position, supine position, left lateral, Fowler’s position 2, supine position 2, prone position 2 and left lateral 2. The order of positions used in sequence 2 was Fowler’s position, prone position, left lateral, supine position, Fowler’s position 2, left lateral 2, prone position 2 and supine position 2. Each woman remained in each position for 6 minutes. For the statistical analyses, we used Wilcoxon’s test for 2 paired samples when comparing the prone position with the other positions. The variables are presented in graphs showing the means and 95% confidence intervals. Trial Registration: Clinical Trial No. ISRCTN41359519 RESULTS: All the parameters were within the standards of normality. There were no differences between positions in terms of maternal heart rate, diastolic blood pressure, oxygen saturation and fetal heart rate. However, there were significant decreases in respiratory rate and systolic blood pressure in prone position 2 compared with left lateral 2. There was an increase in oxygen saturation in prone position compared with Fowler’s position and supine position 2 in both sequences. All the women reported feeling comfortable in the prone position. CONCLUSIONS: The prone position was considered safe and comfortable and could be advantageous for improving oxygen saturation and reducing the systolic blood pressure and respiratory rate. PMID:28658431

  16. Influence of the prone position on a stretcher for pregnant women on maternal and fetal hemodynamic parameters and comfort in pregnancy.

    PubMed

    Oliveira, Claudia; Lopes, Marco Antonio Borges; Rodrigues, Agatha Sacramento; Zugaib, Marcelo; Francisco, Rossana Pulcineli Vieira

    2017-06-01

    To analyze the influence of lying in prone position on a specially designed stretcher on the maternal-fetal hemodynamic parameters and comfort of pregnant women. A randomized, controlled trial with 33 pregnant women divided into 2 groups: pregnant group sequence 1 and pregnant group sequence 2. The order of positions used in sequence 1 was Fowler's position, prone position, supine position, left lateral, Fowler's position 2, supine position 2, prone position 2 and left lateral 2. The order of positions used in sequence 2 was Fowler's position, prone position, left lateral, supine position, Fowler's position 2, left lateral 2, prone position 2 and supine position 2. Each woman remained in each position for 6 minutes. For the statistical analyses, we used Wilcoxon's test for 2 paired samples when comparing the prone position with the other positions. The variables are presented in graphs showing the means and 95% confidence intervals. Trial Registration: Clinical Trial No. ISRCTN41359519. All the parameters were within the standards of normality. There were no differences between positions in terms of maternal heart rate, diastolic blood pressure, oxygen saturation and fetal heart rate. However, there were significant decreases in respiratory rate and systolic blood pressure in prone position 2 compared with left lateral 2. There was an increase in oxygen saturation in prone position compared with Fowler's position and supine position 2 in both sequences. All the women reported feeling comfortable in the prone position. The prone position was considered safe and comfortable and could be advantageous for improving oxygen saturation and reducing the systolic blood pressure and respiratory rate.

  17. Ultrasound-guided regional anesthesia for carotid endarterectomy induces early hemodynamic and stress hormone changes.

    PubMed

    Hoefer, Judith; Pierer, Eve; Rantner, Barbara; Stadlbauer, Karl-Heinz; Fraedrich, Gustav; Fritz, Josef; Kleinsasser, Axel; Velik-Salchner, Corinna

    2015-07-01

    Locoregional anesthesia is an effective method for evaluating cerebral function during carotid endarterectomy (CEA). Landmark-guided regional anesthesia (RA) is currently used for CEA and can provoke substantial perioperative hypertension. Ultrasound-guided RA (US-RA) is a new method for performing RA in CEA; however, the effect on sympathetic activity and blood pressure is uncertain. This study assessed early sympathetic activity during CEA in US-RA compared with general anesthesia (GA). Patients were prospectively randomized to receive US-RA (n = 32) or GA (n = 28) for CEA. The primary end point was the change in systolic arterial blood pressure after induction of anesthesia (just before starting surgery) comparing US-RA with GA. We also recorded heart rate and analyzed concentrations of plasma blood hormones, including cortisol, metanephrine, and normetanephrine at five different times. Creatinine kinase, troponin I, and N-terminal pro-B-type natriuretic peptide were analyzed to detect potential changes in cardiac biomarkers during the procedure. Systolic arterial blood pressure (mean ± standard deviation) increased significantly in US-RA patients compared with GA patients even before surgery was initiated (180 ± 26 mm Hg vs 109 ± 24 mm Hg; P < .001), then remained elevated during the entire surgery and returned to baseline values 1 hour after admission to the postoperative anesthesia care unit. Heart rate (US-RA: 78 ± 16 beats/min, GA: 52 ± 12 beats/min; P < .001) and cortisol levels (US-RA: 155 ± 97 μg/L, GA: 99 ± 43 μg/L; P = .006) were also significantly higher in the US-RA group after induction of anesthesia. Other values did not differ. The US-RA technique for CEA induces temporary intraoperative hypertension and an increase in stress hormone levels. Nevertheless, US-RA is a feasible, effective, and safe form of locoregional for CEA that enables targeted placement of low volumes of local anesthesia under direct visualization. Copyright © 2015

  18. Cortisol Level and Hemodynamic Changes During Tooth Extraction at Hypertensive and Normotensive Patients

    PubMed Central

    Agani, Zana Bajrami; Benedetti, Alberto; Krasniqi, Vjosa Hamiti; Ahmedi, Jehona; Sejfija, Zana; Loxha, Mergime Prekazi; Murtezani, Arben; Rexhepi, Aida Namani; Ibraimi, Zana

    2015-01-01

    Background: The patients that are subjects to oral-surgical interventions produce large amounts of steroids in comparison with healthy patients which are not a subject to any dental intervention. The aim of research was to determine the level of stress hormone cortisol in serum, arterial blood pressure and arterial pulse, and to compare the effectiveness of the usage of lidocaine with adrenalin in comparison with lidocaine without adrenalin during the tooth extraction. Patients and methods: This clinical research includes patients with indication of tooth extraction divided in hypertensive and normotensive patients. Results: There is no important statistical distinction between groups, for the cortisol levels before, during and after tooth extraction regardless of the type of anesthetic used, while we registered higher values of systolic and diastolic values at hypertensive patients, regardless of the type of anesthetic Conclusion: There is significant systolic and diastolic blood pressure rise in both groups of patients hypertensive and normotensive patients, (regardless of anesthetic used with or without vasoconstrictor), who underwent tooth extraction. The special emphasize is attributed to hypertensive patients where these changes are more significant. As per cortisol level and pulse rate, our results indicate no significant statistical difference in between groups. PMID:26005263

  19. Glucose Levels and Hemodynamic Changes in Patients submitted to Routine Dental Extraction under Local Anesthesia with and without Adrenaline.

    PubMed

    Byakodi, Sanjay; Gurjar, Vivek; Soni, Sushant

    2017-01-01

    In maxillofacial surgery, the simplest procedure that we perform is dental extraction. However, this simple procedure is challenged by the patient's poor medical condition. We generally use local anesthesia in combination with adrenaline; however, as we come across patients with diabetes mellitus and cardiovascular diseases who seek dental extraction, we need to be doubly cautious while using adrenaline. In this study, we intend to compare the effects of local anesthesia with adrenaline and local anesthesia without adrenaline on hemodynamic changes (blood pressure and pulse rate) and random blood sugar levels. The comparison is both within the group and between the two groups. Healthy patients between the ages 20 and 60 years were included and randomized into two groups of 50 each. In one group, plain local anesthesia was used, whereas in the other group, local anesthetic solution containing adrenaline was used. Medically compromised patients were excluded from the study. Random blood sugar levels, blood pressures, and pulse rates were recorded in both groups before and 10 minutes after injecting the solutions. The findings were compared. When results are compared within the group, a modest increase in the blood sugar level was noted with the group receiving local anesthetic with adrenaline. However, blood pressure and pulse rate showed no significant difference. Similarly, when between-the-groups comparison was done, not a single variable showed any significant difference. The patients injected with local anesthesia containing adrenaline showed similar results to that observed in the patients injected with local anesthesia without adrenaline. However, there is a statistically significant rise in blood sugar levels when a local anesthetic is injected with adrenaline. Dental extractions in healthy individuals can be safely performed with local anesthetic containing adrenaline. However, in diabetic patients, it should be cautiously used.

  20. Hemodynamic changes at the saphenofemoral junction during the application of a below-knee graduated compression stocking.

    PubMed

    Lattimer, Christopher R; Azzam, Mustapha; Kalodiki, Evi; Geroulakos, George

    2012-12-01

    It is strongly recommended that patients wear compression after foam sclerotherapy, but pulling up a stocking may inadvertently flush foam into the femoral vein, which may increase the risk of systemic side effects and reduce great saphenous vein (GSV) occlusion rates. The hypothesis was that a stocking pull-up maneuver would increase flow in the GSV. The aim was to quantify this using duplex ultrasound. Twelve consecutive patients with primary varicose veins were studied. A below-knee 23- to 32-mmHg graduated elastic compression stocking was placed over the foot, leaving a cuff of redundant stocking around the ankle. Duplex ultrasound over the saphenofemoral junction was used to measure peak velocity (PV) and volume flow (VF) before and while the stocking was being pulled up. The pull-up maneuver caused a median 17.7 times increase in PV (interquartile range (IQR) 14.2-23.9), from 7.6 cm/seconds (IQR 6.4-9.8 cm/seconds) to 150.5 cm/seconds (IQR 110-187 cm/seconds) and a 9.4 times increase in VF (IQR 7.7-10.3), from 50.9 mL/minutes (IQR 33.8-78.9 mL/minutes) to 458.7 mL/minutes (IQR 292.1-593 mL/minutes) (p = .002). A stocking causes significant hemodynamic changes within the GSV. These forces could be avoided by the partial application of a stocking to knee level before foam injection. Further work may establish the implication of these findings in patients treated with foam sclerotherapy. © 2012 by the American Society for Dermatologic Surgery, Inc. Published by Wiley Periodicals, Inc.

  1. Hemodynamic and radionuclide effects of acute captopril therapy for heart failure: changes in left and right ventricular volumes and function at rest and during exercise

    SciTech Connect

    Massie, B.; Kramer, B.L.; Topic, N.; Henderson, S.G.

    1982-06-01

    Although the resting hemodynamic effects of captopril in congestive heart failure are known, little information is available about the hemodynamic response to captopril during exercise or about changes in noninvasive measurements of the size and function of both ventricles. In this study, 14 stable New York Heart Association class III patients were given 25 mg of oral captopril. Rest and exercise hemodynamic measurements and blood pool scintigrams were performed simultaneously before and 90 minutes after captopril. The radionuclide studies were analyzed for left and right ventricular end-diastolic volumes, end-systolic volumes, ejection fractions and pulmonary blood volume. The primary beneficial responses at rest were decreases in left and right ventricular end-diastolic volumes from 388 +/- 81 to 350 +/- 77 ml and from 52 +/- 26 to 43 +/- 20 volume units, respectively, and in their corresponding filling pressures, from 24 +/- 10 to 17 +/- 9 mm Hg and 10 +/- 5 to 6 +/- 5 mm Hg. Although stroke volume did not increase significantly, both left and right ventricular ejection fractions increased slightly, from 19 +/- 6% to 22+/- 5% and from 25 +/- 9% to 29 +/- 11%, respectively. During exercise, similar changes were noted in both hemodynamic and radionuclide indexes. This, in patients with moderate symptomatic limitation from chronic heart failure, captopril predominantly reduces ventricular volume and filling pressure, with a less significant effect on cardiac output. These effects persist during exercise, when systemic vascular resistance is already very low. Radionuclide techniques are valuable in assessing the drug effect in these subjects, particularly when ventricular volumes are also measured.

  2. Hemodynamic and radionuclide effects of acute captopril therapy for heart failure: changes in left and right ventricular volumes and function at rest and during exercise

    SciTech Connect

    Massie, B.; Kramer, B.L.; Topic, N.; Henderson, S.G.

    1982-06-01

    Although the resting hemodynamic effects of captopril in congestive heart failure are known, little information is available about the hemodynamic response to captopril during exercise or about changes in noninvasive measurements of the size and function of both ventricles. In this study, 14 stable New York Heart Association class III patients were given 25 mg of oral captopril. Rest and exercise hemodynamic measurements and blood pool scintigrams were performed simultaneously before and 90 minutes after captopril. The radionuclide studies were analyzed for left and right ventricular end-diastolic volumes, end-systolic volumes, ejection fractions and pulmonary blood volume. The primary beneficial responses at rest were decreases in left and right ventricular end-diastolic volumes from 388 + 81 to 350 + 77 ml (p < 0.01) and from 52 + 26 to 43 + 20 volume units (p < 0.01), respectively, and in their corresponding filling pressures, from 24 + 10 to 17 + 9 mm Hg and 10 + 5 to and + 5 mm Hg (both p < 0.01). Altough stroke volume did not increase significantly, both left and right ventricular ejection fractions increased slightly, from 19 + 6% to 22 + 5% and from 25 + 9% to 29 + 11%, respectively (both p < 0.01). During exercise, similar changes were noted in both hemodynamic and radionuclide indexes. Thus, in patients with moderate symptomatic limitation from chronic heart failure, captopril predominantly reduces ventricular volume and filling pressure, with a less significant effect on cardiac output. These effects persist during exercise, when systemic vascular resistance is already very low. Radionuclide techniques are valuable in assessing the drug effect in these subjects, particularly when ventricular volumes are also measured.

  3. Improvement in cerebral hemodynamic parameters and outcomes after superficial temporal artery-middle cerebral artery bypass in patients with severe stenoocclusive disease of the intracranial internal carotid or middle cerebral arteries.

    PubMed

    Low, Shiong Wen; Teo, Kejia; Lwin, Sein; Yeo, Leonard L L; Paliwal, Prakash R; Ahmad, Aftab; Sinha, Arvind K; Teoh, Hock Luen; Wong, Lily Y H; Chong, Vincent F; Seet, Raymond C S; Chan, Bernard P L; Yeo, Tseng Tsai; Chou, Ning; Sharma, Vijay K

    2015-09-01

    Both the older and the recent extracranial-intracranial (EC-IC) bypass trials for symptomatic carotid occlusion failed to demonstrate a reduction in stroke recurrence. However, the role of superficial temporal artery (STA)-middle cerebral artery (MCA) bypass in patients with symptomatic intracranial stenoocclusive disease has been rarely evaluated. The authors evaluated serial changes in various cerebral hemodynamic parameters in patients with severe stenoocclusive disease of the intracranial internal carotid artery (ICA) or middle cerebral artery (MCA) and impaired cerebral vasodilatory reserve (CVR), treated by STA-MCA bypass surgery or medical treatment. Patients with severe stenoocclusive disease of the intracranial ICA or MCA underwent transcranial Doppler (TCD) ultrasonography and CVR assessment using the breath-holding index (BHI). Patients with impaired BHI (< 0.69) were further evaluated with acetazolamide-challenge technitium-99m hexamethylpropyleneamine oxime ((99m)Tc HMPAO) SPECT. STA-MCA bypass surgery was offered to patients with impaired CVR on SPECT. All patients underwent TCD and SPECT at 4 ± 1 months and were followed up for cerebral ischemic events. A total of 112 patients were included. This total included 73 men, and the mean age of the entire study population was 56 years (range 23-78 years). (99m)Tc HMPAO SPECT demonstrated impaired CVR in 77 patients (69%). Of these 77 patients, 46 underwent STA-MCA bypass while 31 received best medical treatment. TCD and acetazolamide-challenge (99m)Tc HMPAO SPECT repeated at 4 ± 1 months showed significant improvement in the STA-MCA bypass group. During a mean follow-up of 34 months (range 18-39 months), only 6 (13%) of 46 patients in the bypass group developed cerebral ischemic events, as compared with 14 (45%) of 31 patients receiving medical therapy (absolute risk reduction 32%, p = 0.008). STA-MCA bypass surgery in carefully selected patients with symptomatic severe intracranial stenoocclusive

  4. Plasma ADAMTS-13 protein is not associated with portal hypertension or hemodynamic changes in patients with cirrhosis.

    PubMed

    Wiese, Signe; Timm, Annette; Nielsen, Lars B; Goetze, Jens P; Bendtsen, Flemming; Møller, Søren

    2016-04-01

    Activated hepatic stellate cells synthesize the matrix metalloprotease ADAMTS13, which may be involved in the development of liver cirrhosis and portal hypertension. Plasma ADAMTS13 activity has been reported as both increased and decreased in cirrhosis, but ADAMTS13 protein has not previously been examined. To evaluate ADAMTS13 protein in the hepatic circulation and the relation to disease severity, portal pressure, and systemic hemodynamics in cirrhotic patients. Sixty-one cirrhotic patients (Child class: A=22; B=21; C=18) and nine healthy controls underwent a liver vein catheterization with measurement of splanchnic and systemic hemodynamics, and plasma ADAMTS13 protein concentration in a hepatic vein and the femoral artery. ADAMTS13 protein concentrations were increased in cirrhotic patients compared with controls (774ng/ml [IQR: 585-955] vs. 538ng/ml [IQR: 484-631], p<0.03). There were no significant correlations to MELD score, Child Pugh score, portal pressure, nor systemic vascular resistance or cardiac output. The increased concentration of ADAMTS13 protein in the hepatic circulation may reflect an increased number of active hepatic stellate cells in cirrhosis. However, ADAMTS13 was unrelated to portal hypertension and systemic hemodynamics. In conclusion, ADAMTS13 does not appear to be associated to disease severity or the hemodynamic derangement in patients with cirrhosis. Copyright © 2015 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.

  5. Common MicroRNA Signatures in Cardiac Hypertrophic and Atrophic Remodeling Induced by Changes in Hemodynamic Load

    PubMed Central

    Neuber, Christiane; Emmons, Julius; Biermann, Daniel; Christalla, Thomas; Grundhoff, Adam; Eschenhagen, Thomas; Zimmermann, Wolfram Hubertus; Ehmke, Heimo

    2010-01-01

    changes in hemodynamic load. PMID:21151612

  6. Regional changes in constitutive nitric oxide synthase and the hemodynamic consequences of its inhibition in lipopolysaccharide-treated pigs.

    PubMed

    Javeshghani, D; Magder, S

    2001-09-01

    The role of constitutive nitric oxide synthases (cNOS) in sepsis remains controversial. Part of the problem is that many of the studies have been performed in rats, which respond differently than larger animals. Our objective, therefore, was to determine whether cNOS, i.e. ecNOS (NOS-3) and nNOS (NOS-1) are still active in vessels of pigs treated with lipopolysaccharide (LPS) from Escherichia coli. We also characterized the dose-response relationship of the NOS inhibitor N(G)-nitro-L-arginine-methyl-ester (L-NAME) in the arterial, venous, and pulmonary circuits as a reflection of NO production. We anesthetized and ventilated 14 pigs, which were instrumented for hemodynamic measurements. We measured mean circulatory filling pressure and resistance to venous return by transiently arresting the circulation with a balloon in the right atrium. Animals were given 20 microg/kg of LPS (n = 8) or saline (n = 6) over 2 h. They were then given progressively increasing doses of L-NAME (0.5 to 16 microg/kg). We injected 20 microg boluses of norepinephrine at baseline, after 2 h, and after 0.5, 4, and 16 microg of L-NAME to test the pressor response. Tissue was obtained from six control animals followed for 2 h, eight animals treated with LPS for 2 h and then sacrificed, and four animals treated for 2 h and sacrificed after 2 more h. Cardiac output did not change, and the systemic vascular resistance fell in LPS animals. By Western analysis, ecNOS was increased in LPS animals at 2 and 4 h in the aorta and vena cava, and this was paralleled by changes in nNOS in the vena cava. In contrast, ecNOS decreased in the pulmonary artery and nNOS did not change. Calcium-dependent NOS activity increased with LPS in the aorta and vena cava but decreased in pulmonary artery at 4 h. The dose-response relationships to L-NAME for systemic vascular resistance, resistance to venous return, and cardiac output were shifted to the left after LPS in support of increased sensitivity supporting

  7. Plasma volume restoration with salt tablets and water after bed rest prevents orthostatic hypotension and changes in supine hemodynamic and endocrine variables.

    PubMed

    Waters, Wendy W; Platts, Steven H; Mitchell, Brett M; Whitson, Peggy A; Meck, Janice V

    2005-02-01

    Head-down bed rest changes the values of many cardiovascular and endocrine variables and also elicits significant hypovolemia. Because previous studies had not controlled for hypovolemia, it is unknown whether the reported changes were primary effects of bed rest or secondary effects of bed rest-induced hypovolemia. We hypothesized that restoring plasma volume with salt tablets and water after 12 days of head-down bed rest would result in an absence of hemodynamic and endocrine changes and a reduced incidence of orthostatic hypotension. In 10 men, we measured changes from pre-bed-rest to post-bed-rest in venous and arterial pressures; heart rate; stroke volume; cardiac output; vascular resistance; plasma norepinephrine, epinephrine, vasopressin, renin activity (PRA), and aldosterone responses to different tilt levels (0 degrees, -10 degrees, 20 degrees, 30 degrees, and 70 degrees); and plasma volume and platelet alpha2- and lymphocyte beta2-adrenoreceptor densities and affinities (0 degrees tilt only). Fluid loading at the end of bed rest restored plasma volume and resulted in the absence of post-bed-rest orthostatic hypotension and changes in supine hemodynamic and endocrine variables. Fluid loading did not prevent post-bed-rest increases in beta2-adrenoreceptor density or decreases in the aldosterone-to-PRA ratio (P = 0.05 for each). Heart rate, epinephrine, and PRA responses to upright tilt after bed rest were increased (P < 0.05), despite the fluid load. These results suggest that incidents of orthostatic hypotension and many of the changes in supine hemodynamic and endocrine variables in volume-depleted bed-rested subjects occur secondarily to the hypovolemia. Despite normovolemia after bed rest, beta2-adrenoreceptors were upregulated, and heart rate, epinephrine, and PRA responses to tilt were augmented, indicating that these changes are independent of volume depletion.

  8. Changes in platelet parameters in leukocytosis.

    PubMed

    Ozturk, Nurinnisa; Baygutalp, Nurcan Kilic; Bakan, Ebubekir; Altas, Gulsum Feyza; Polat, Harun; Dorman, Emrullah

    2016-01-01

    In recent years, platelets are known to have a large variety of functions in many pathophysiological processes and their interaction with endothelial cells and leukocytes is known to play an important role in the pathophysiology of vascular inflammation. The aim of this study was to investigate the relationship between white blood cell count in conditions resulting in leukocytosis and platelet count and platelet parameters including mean platelet volume, platelet distribution width, and plateletcrit. White blood cell counts count and all platelet parameters were evaluated in 341 results of normal complete blood count (of which the white blood cell counts were within reference range, group 1) and 327 results of elevated white blood cell counts count (group 2). There was a significant difference between these two groups in PLT counts and PCT values, being higher in Group 2. However, there was no statistically significant difference between two groups in MPV and PDW values. On the other hand, there were statistically significant, but weak, correlations between the WBC and platelet counts in both groups (p<0.01, r=0.235 for group 1, p<0.05, r=0.116 for group 2). As a conclusion PLT count and PCT values increase in infectious conditions. This study and previous studies show that PLTs are employed in infectious conditions but the exact mechanism and the exact clinical importance of this response remains to be cleared by further studies.

  9. Neural and Hemodynamic Responses Elicited by Forelimb- and Photo-stimulation in Channelrhodopsin-2 Mice: Insights into the Hemodynamic Point Spread Function

    PubMed Central

    Vazquez, Alberto L.; Fukuda, Mitsuhiro; Crowley, Justin C.; Kim, Seong-Gi

    2014-01-01

    Hemodynamic responses are commonly used to map brain activity; however, their spatial limits have remained unclear because of the lack of a well-defined and malleable spatial stimulus. To examine the properties of neural activity and hemodynamic responses, multiunit activity, local field potential, cerebral blood volume (CBV)-sensitive optical imaging, and laser Doppler flowmetry were measured from the somatosensory cortex of transgenic mice expressing Channelrhodopsin-2 in cortex Layer 5 pyramidal neurons. The magnitude and extent of neural and hemodynamic responses were modulated using different photo-stimulation parameters and compared with those induced by somatosensory stimulation. Photo-stimulation-evoked spiking activity across cortical layers was similar to forelimb stimulation, although their activity originated in different layers. Hemodynamic responses induced by forelimb- and photo-stimulation were similar in magnitude and shape, although the former were slightly larger in amplitude and wider in extent. Altogether, the neurovascular relationship differed between these 2 stimulation pathways, but photo-stimulation-evoked changes in neural and hemodynamic activities were linearly correlated. Hemodynamic point spread functions were estimated from the photo-stimulation data and its full-width at half-maximum ranged between 103 and 175 µm. Therefore, submillimeter functional structures separated by a few hundred micrometers may be resolved using hemodynamic methods, such as optical imaging and functional magnetic resonance imaging. PMID:23761666

  10. Practical issues of hemodynamic monitoring at the bedside.

    PubMed

    Polanco, Patricio M; Pinsky, Michael R

    2006-12-01

    The hemodynamic monitoring of a surgical patient acquires a major relevance in high-risk patients and those suffering from surgical diseases associated with hemodynamic instability, such as hemorrhagic or septic shock. This article reviews the fundamental physiologic principles needed to understand hemodynamic monitoring at the bedside. Monitoring defines stability, instability, and response to therapy. The major hemodynamic parameters measured and derived from invasive hemodynamic monitoring, such as arterial, central venous, and pulmonary catheterization, are discussed, as are its clinical indications, benefits, and complications. The current clinical data relevant to hemodynamic monitoring are reviewed and discussed.

  11. Renal 20-HETE inhibition attenuates changes in renal hemodynamics induced by L-NAME treatment in pregnant rats.

    PubMed

    Huang, Hui; Zhou, Yiqiang; Raju, Venugopal T; Du, Juan; Chang, Hsin-Hsin; Wang, Cong-Yi; Brands, Michael W; Falck, John R; Wang, Mong-Heng

    2005-11-01

    We previously reported that inhibition of nitric oxide (NO) synthesis by N-nitro-L-arginine methyl ester (L-NAME) during late pregnancy leads to increased production of renal vascular 20-hydroxyeicosatetraenoic acid (20-HETE), a cytochrome P-450 (CYP) 4A-derived vasoconstrictor, in pregnant rats. However, the effect of upregulation of vascular 20-HETE production on renal function after NO inhibition is not known. To test the hypothesis that increased gestational vascular 20-HETE synthesis after NO inhibition is involved in mediating blood pressure and renal functional changes, we first determined the IC(50) value of the effect of nitroprusside (SNP), a NO donor, on renal 20-HETE production in cortical microsomes. We then divided pregnant rats and age-matched virgin rats into a vehicle control group, an L-NAME treatment group (0.25 mg/ml in drinking water), and a group treated with L-NAME plus N-methylsulfonyl-12,12-dibromododec-11-enamide (DDMS; CYP4A-selective inhibitor, 10 mg.kg(-1).day(-1) iv). After 4 days of treatment, we measured blood pressure, renal blood flow (RBF), renal vascular resistance (RVR), and glomerular filtration rate (GFR) in each group. The addition of SNP (IC(50) = 22 microM) decreased renal cortical 20-HETE production. In pregnant rats, L-NAME treatment led to significantly higher mean arterial pressure (MAP) and RVR, and lower RBF and GFR. Combined treatment with DDMS and L-NAME significantly attenuated the increases in MAP and RVR and the decrease in GFR, but not the reduction in RBF induced by L-NAME treatment. L-NAME and L-NAME plus DDMS had no significant impact on renal hemodynamics in virgin rats. In addition, chronic treatment with DDMS selectively inhibited cortical 20-HETE production without a significant effect on CYP4A expression in L-NAME-treated pregnant rats. In conclusion, NO effectively inhibits renal cortical microsomal 20-HETE production in female rats. In pregnant rats, the augmentation of renal 20-HETE production after

  12. Role of terminal and anastomotic circulation in the patency of arteries jailed by flow-diverting stents: from hemodynamic changes to ostia surface modifications.

    PubMed

    Iosif, Christina; Berg, Philipp; Ponsonnard, Sebastien; Carles, Pierre; Saleme, Suzana; Ponomarjova, Sanita; Pedrolo-Silveira, Eduardo; Mendes, George A C; Waihrich, Eduardo; Trolliard, Gilles; Couquet, Claude-Yves; Yardin, Catherine; Mounayer, Charbel

    2017-05-01

    OBJECTIVE The outcome for jailing arterial branches that emerge near intracranial aneurysms during flow-diverting stent (FDS) deployment remains controversial. In this animal study, the authors aimed to elucidate the role of collateral supply with regard to the hemodynamic changes and neointimal modifications that occur from jailing arteries with FDSs. To serve this purpose, the authors sought to quantify 1) the hemodynamic changes that occur at the jailed arterial branches immediately after stent placement and 2) the ostia surface values at 3 months after stenting; both parameters were investigated in the presence or absence of collateral arterial flow. METHODS After an a priori power analysis, 2 groups (Group A and Group B) were created according to an animal flow model for terminal and anastomotic arterial circulation; each group contained 7 Large White swine. Group A animals possessed an anastomotic-type arterial configuration to supply the territory of the right ascending pharyngeal artery (APhA), while Group B animals possessed a terminal-type arterial configuration to supply the right APhA territory. Subsequently, all animals underwent FDS placement, thereby jailing the right APhAs. Mean flow rates and velocities inside the jailed branches were quantified using time-resolved 3D phase-contrast MR angiography before and after stenting. Three months after stent placement, the jailed ostia surface values were quantified on scanning electron micrographs. The data were analyzed using descriptive statistics and group comparisons with parametric and nonparametric tests. RESULTS The endovascular procedures were feasible, and there were no findings of in situ thrombus formation on postprocedural optical coherence tomography or ischemia on postprocedural diffusion-weighted imaging. In Group A, the mean flow rate values at the jailed right APhAs were reduced immediately following stent placement as compared with values obtained before stent placement (p = 0.02, power: 0

  13. Changes in Doppler parameters of portal pressure after interventional management of hepatocellular carcinoma.

    PubMed

    El Sherbiny, Walid; AbdelRahman, Ashraf; Diasty, Muhammad; Shaltout, Shaker Wagih

    2016-08-01

    Hepatocellular carcinoma (HCC) has many options for management; some of them are complicated by development of portal hypertension (PHT). Doppler ultrasound is an effective method to diagnose and monitor PHT changes after HCC ablation procedures. The aim of this study is to investigate changes in portal pressure hemodynamics of HCC patients following treatment with different interventional strategies: radiofrequency ablation (RFA), microwave ablation (MWA), and transarterial chemoembolization (TACE). A total of 60 patients with HCC were divided into three main groups, and each group received a different type of therapy (RFA, MWA, and TACE). Full medical record and basic investigations were performed including Doppler ultrasound and upper GIT endoscopy for evaluation of PHT parameters, and then repeated after three months of ablation. RFA is associated with the increased splenic artery resistive index, while MWA has no significant impact on PHT indices. TACE has led to a marked increase in liver vascular index with significant decrease in hepatic artery resistive index and PHI after treatment. No significant changes in esophageal varices were observed by upper GIT endoscopy following all ablation methods. RFA is quite safe but associated with degree of PHT. On the contrary, TACE is associated with improved PHT parameters. MWA has no significant association to development of PHT following the technique. Doppler ultrasound could be used as a reliable and effective method of evaluation of PHT post ablation for HCC.

  14. Association Among SNAP-25 Gene DdeI and MnlI Polymorphisms and Hemodynamic Changes During Methylphenidate Use: A Functional Near-Infrared Spectroscopy Study

    PubMed Central

    Öner, Özgür; Akın, Ata; Herken, Hasan; Erdal, Mehmet Emin; Çiftçi, Koray; Ay, Mustafa Ertan; Bicer, Duygu; Öncü, Bedriye; Bozkurt, Ozlem Hekim; Münir, Kerim; Yazgan, Yankı

    2011-01-01

    Objective To investigate the interaction of treatment-related hemodynamic changes with genotype status for Synaptosomal associated protein 25 (SNAP-25) gene in participants with attention deficit hyperactivity disorder (ADHD) on and off single dose short-acting methylphenidate treatment with functional near-infrared spectroscopy (fNIRS). Method A total of 15 right-handed adults and 16 right-handed children with DSM-IV diagnosis of ADHD were evaluated. Ten milligrams of short-acting methylphenidate was administered in a crossover design. Results Participants with SNAP-25 DdeI T/T genotype had decreased right deoxyhemoglobin ([HHb]) with treatment. SNAP-25 MnlI genotype was also associated with right deoxyhemoglobin ([HbO2]) and [HHb] changes as well as left [HHb] change. When the combinations of these genotypes were taken into account, the participants with [DdeI C/C or T/C and MnlI G/G or T/G] genotype had increased right [HHb] with MPH use whereas the participants with [DdeI T/T and MnlI T/T] or [DdeI T/T and MnlI G/G or T/G] genotypes had decreased right prefrontal [HHb]. Conclusions These results suggested that SNAP-25 polymorphism might be associated with methylphenidate induced brain hemodynamic changes in ADHD participants. PMID:20679152

  15. Establishment of the intracranial hemodynamic model based on contrast medium and clinical applications

    PubMed Central

    Cheng, Yaoer; He, Wen

    2016-01-01

    Abstract Ischemic cerebrovascular diseases are one of the most common vascular diseases in aged people and CT perfusion (CTP) is a very popular tool to detect the ischemic changes in brain vascular. The present study aims to establish a novel intracranial hemodynamic model to simulate anterior cerebral artery blood flow, and compare the actual and simulated hemodynamic parameters of healthy people and patients with carotid stenosis or occlusion. A mathematical model of the intracranial hemodynamic was generated using MATLAB software, and data from patients with or without infarct disease (57 and 44 cases, respectively) were retrospectively collected to test the new model. The actual time-density curve (TDC) of anterior cerebral artery was obtained from the original intracranial CTP data, and simulated TDC was calculated from our intracranial hemodynamic model. All model parameters were adjusted according to patients’ sex, height, and weight. Time to peak enhancement (TTP), maximum enhancement (ME), and mean transit time (MTT) were selected to evaluate the status of hemodynamics. In healthy people, there were no significant differences of TTP and ME between actual and simulated curves. For patients with infarct symptoms, ME was significantly decreased in actual data compared with simulated curve, while there was no obvious difference of TTP between actual and simulated data. Moreover, MTT was delayed in infarct patients compared with healthy people. Our group generated a computer-based, physiologic model to simulate intracranial hemodynamics. The model successfully simulated anterior cerebral artery hemodynamics in normal healthy people and showed noncompliant ME and MTT in infarct patients, reflecting their abnormal cerebral hemodynamic status. The digital model is reliable and may help optimize the protocol of contrast medium enhancement in intracranial CT, and provide a solid tool to study intracranial hemodynamics. PMID:27930555

  16. Establishment of the intracranial hemodynamic model based on contrast medium and clinical applications.

    PubMed

    Cheng, Yaoer; He, Wen

    2016-12-01

    Ischemic cerebrovascular diseases are one of the most common vascular diseases in aged people and CT perfusion (CTP) is a very popular tool to detect the ischemic changes in brain vascular. The present study aims to establish a novel intracranial hemodynamic model to simulate anterior cerebral artery blood flow, and compare the actual and simulated hemodynamic parameters of healthy people and patients with carotid stenosis or occlusion.A mathematical model of the intracranial hemodynamic was generated using MATLAB software, and data from patients with or without infarct disease (57 and 44 cases, respectively) were retrospectively collected to test the new model. The actual time-density curve (TDC) of anterior cerebral artery was obtained from the original intracranial CTP data, and simulated TDC was calculated from our intracranial hemodynamic model. All model parameters were adjusted according to patients' sex, height, and weight. Time to peak enhancement (TTP), maximum enhancement (ME), and mean transit time (MTT) were selected to evaluate the status of hemodynamics.In healthy people, there were no significant differences of TTP and ME between actual and simulated curves. For patients with infarct symptoms, ME was significantly decreased in actual data compared with simulated curve, while there was no obvious difference of TTP between actual and simulated data. Moreover, MTT was delayed in infarct patients compared with healthy people.Our group generated a computer-based, physiologic model to simulate intracranial hemodynamics. The model successfully simulated anterior cerebral artery hemodynamics in normal healthy people and showed noncompliant ME and MTT in infarct patients, reflecting their abnormal cerebral hemodynamic status. The digital model is reliable and may help optimize the protocol of contrast medium enhancement in intracranial CT, and provide a solid tool to study intracranial hemodynamics.

  17. Nonlinear extension of a hemodynamic linear model for coherent hemodynamics spectroscopy

    PubMed Central

    Sassaroli, Angelo; Kainerstorfer, Jana M.; Fantini, Sergio

    2015-01-01

    In this work, we are proposing an extension of a recent hemodynamic model (Fantini, 2014 a), which was developed within the framework of a novel approach to the study of tissue hemodynamics, named coherent hemodynamics spectroscopy (CHS). The previous hemodynamic model, from a signal processing viewpoint, treats the tissue microvasculature as a linear time-invariant system, and considers changes of blood volume, capillary blood flow velocity and the rate of oxygen diffusion as inputs, and the changes of oxy-, deoxy-, and total hemoglobin concentrations (measured in near infrared spectroscopy) as outputs. The model has been used also as a forward solver in an inversion procedure to retrieve quantitative parameters that assess physiological and biological processes such as microcirculation, cerebral autoregulation, tissue metabolic rate of oxygen, and oxygen extraction fraction. Within the assumption of “small” capillary blood flow velocity oscillations the model showed that the capillary and venous compartments “respond” to this input as low pass filters, characterized by two distinct impulse response functions. In this work, we do not make the assumption of “small” perturbations of capillary blood flow velocity by solving without approximations the partial differential equation that governs the spatio-temporal behavior of hemoglobin saturation in capillary and venous blood. Preliminary comparison between the linear time-invariant model and the extended model (here identified as nonlinear model) are shown for the relevant parameters measured in CHS as a function of the oscillation frequency (CHS spectra). We have found that for capillary blood flow velocity oscillations with amplitudes up to 10% of the baseline value (which reflect typical scenarios in CHS), the discrepancies between CHS spectra obtained with the linear and nonlinear models are negligible. For larger oscillations (~50%) the linear and nonlinear models yield CHS spectra with differences

  18. Effect of H1- and H2-receptor antagonists on the hemodynamic changes induced by the intravenous administration of ketamine in sevoflurane-anesthetized cats.

    PubMed

    Costa-Farré, C; García, F; Andaluz, A; Torres, R; de Mora, F

    2005-06-01

    The anesthetic ketamine has been reported to cause both an increase of the plasma histamine concentration, notably in cats, and a cardiovascular depression. The latter has been described in humans and in other species. However the relevance of the histamine fluctuation for the ketamine-induced hemodynamic changes has not been determined. We studied the contribution of histamine to the hemodynamic effects induced by IV ketamine (7 mg/kg) in 12 sevoflurane anesthetized cats, of which half had been pre-treated with combined H(1)- and H(2) -receptor antagonists. The mean arterial pressure (MAP) and the heart rate (HR) from both untreated (group C) and pre-treated (group AH) cats were recorded before and after the ketamine administration. The plasma histamine concentration was also measured. Plasma histamine fluctuations in the control and the antihistamine-treated group followed a similar pattern (no statistical differences); an initial rise that peaked 2 min after ketamine injection (from 0.63 +/- 0.11 ng/ml to 2.22 +/- 0.69 ng/ml in the C group, and from 0.71 +/- 0.10 ng/ml to 1.09 +/- 0.28 ng/ml in the AH group) followed by an immediate decrease in plasma concentrations. As for the hemodynamic variables under analysis, in the control group ketamine administration was followed by an early 30.3 +/- 8.1% reduction (p < 0.005) in the MAP with no associated changes in the HR. In the antihistamine pre-treated group, ketamine caused a further decrease of the MAP (41.7 +/- 2.3%), and a significant (p < 0.01) 11.6 +/- 2.9% reduction of the HR. Ketamine in anesthetized cats triggers histamine release and induces cardiovascular depression. The depression is more pronounced under the blockade of histamine activity through histamine receptor antagonists.

  19. [Ibopamine--acute hemodynamic, renal and neurohumoral effects].

    PubMed

    Wehling, M; Theisen, K

    1991-01-01

    Ibopamine (IP) is a novel dopamine analogue for which beneficial effects have been shown in chronic heart failure. Hemodynamic effects of the substance include an increase in cardiac output and a decrease in the peripheral resistance. Aside from these hemodynamic effects, changes in renal (increased diuresis) and neurohumoral parameters (decreased plasma renin activity, aldosterone, norepinephrine, increased ANF and cGMP) have been found. The renal effects may originate from three independent mechanisms: 1) direct impact of improved hemodynamic parameters on the renal perfusion; 2) the improved cardiac performance results in a reduction of compensatory hormonal adaptations, such as the activation of the renin-angiotensin-aldosterone-axis or the sympathetic system; 3) direct effects on the intrarenal hemodynamic and glomerular/tubular functions induced by stimulation of renal dopaminergic receptors. The continued decrease of the plasma renin activity by 35% results in a reduction of the plasma levels of angiotensin II and aldosterone. Additionally, an increase in plasma atrial natriuretic factor (ANF) and its second messenger cyclic guanosine monophosphate (cGMP) was observed after ibopamine, which could contribute to the diuretic action of the drug. These findings underline the importance of extrarenal effects of a drug in the treatment of heart failure, this may essentially contribute to the improvement of cardiac performance, independent of positive inotropy.

  20. Effect of an epinephrine mixture for interscalene block on hemodynamic changes after the beach chair position under general anesthesia: a retrospective study

    PubMed Central

    Kim, Bum-June; Hong, Boo-Hwi; Lee, Ji-Yong; Lee, Sun-Yeul; Lee, Jung-Un; Kim, Yoon-Hee; Lee, Won-Hyung; Yoon, Seok-Hwa

    2017-01-01

    Background The beach chair position (BCP) can cause significant hypotension. Epinephrine is used to prolong the duration of local anesthetics; it is also absorbed into blood and can exert systemic effects. This study determined the effects of epinephrine mixed with ropivacaine for an interscalene block (ISB) on hemodynamic changes related to BCP. Methods Patient data collected from March 2013 to August 2014 were used retrospectively. We divided the patients into three groups: 1) ISB only, 2) I+G (general anesthesia after ISB without epinephrine), and 3) I+E+G (general anesthesia after ISB with epinephrine). Mean blood pressure (MBP) and heart rate (HR) were measured for 30 minutes at 5-minute intervals. Results The study analyzed data from 431 patients. MBP tended to decrease gradually in the groups I+G and I+E+G. There were significant differences in MBP between the groups I+G and I, and between the groups I+G and I+E+G. Group I+E+G showed a significant increase in HR compared with the other two groups. Conclusions ISB with an epinephrine mixture did not prevent hypotension caused by the BCP after general anesthesia. HR increased only in response to the epinephrine mixture. A well-planned prospective study is required to compare hemodynamic changes in that context. PMID:28367287

  1. Assessment of contrast-enhanced ultrasonography of the hepatic vein for detection of hemodynamic changes associated with experimentally induced portal hypertension in dogs.

    PubMed

    Morishita, Keitaro; Hiramoto, Akira; Michishita, Asuka; Takagi, Satoshi; Hoshino, Yuki; Itami, Takaharu; Lim, Sue Yee; Osuga, Tatsuyuki; Nakamura, Sayuri; Ochiai, Kenji; Nakamura, Kensuke; Ohta, Hiroshi; Yamasaki, Masahiro; Takiguchi, Mitsuyoshi

    2017-04-01

    OBJECTIVE To assess the use of contrast-enhanced ultrasonography (CEUS) of the hepatic vein for the detection of hemodynamic changes associated with experimentally induced portal hypertension in dogs. ANIMALS 6 healthy Beagles. PROCEDURES A prospective study was conducted. A catheter was surgically placed in the portal vein of each dog. Hypertension was induced by intraportal injection of microspheres (10 to 15 mg/kg) at 5-day intervals via the catheter. Microsphere injections were continued until multiple acquired portosystemic shunts were created. Portal vein pressure (PVP) was measured through the catheter. Contrast-enhanced ultrasonography was performed before and after establishment of hypertension. Time-intensity curves were generated from the region of interest in the hepatic vein. Perfusion variables measured for statistical analysis were hepatic vein arrival time, time to peak, time to peak phase (TTPP), and washout ratio. The correlation between CEUS variables and PVP was assessed by use of simple regression analysis. RESULTS Time to peak and TTPP were significantly less after induction of portal hypertension. Simple regression analysis revealed a significant negative correlation between TTPP and PVP. CONCLUSIONS AND CLINICAL RELEVANCE CEUS was useful for detecting hemodynamic changes associated with experimentally induced portal hypertension in dogs, which was characterized by a rapid increase in the intensity of the hepatic vein. Furthermore, TTPP, a time-dependent variable, provided useful complementary information for predicting portal hypertension. IMPACT FOR HUMAN MEDICINE Because the method described here induced presinusoidal portal hypertension, these results can be applied to idiopathic portal hypertension in humans.

  2. The age-related hemodynamic changes of blood pressure and their impact on the incidence of cardiovascular disease and stroke: new evidence.

    PubMed

    Chrysant, Steven G; Chrysant, George S

    2014-02-01

    There is a linear change in blood pressure (BP) with the advancement of age from predominantly diastolic BP (DBP) in the young to predominantly systolic BP (SBP) in the old. This change is caused by the stiffening of the large arteries and the loss of elastic recoil as a result of replacement of the elastic fibers with collagen fibers. The result of this ageing process leads to an increase in pulse wave velocity and widening of pulse pressure. These hemodynamic changes are associated with an increased incidence in cardiovascular diseases (CVDs) and strokes. Recently, an inverse relationship with stroke risk was noted when the DBP was <71 mm Hg in persons older than 60 years. Accordingly, when treating SBP in the elderly, care should be taken not to lower the DBP below this level in order to minimize the risk for CVD and stoke. ©2013 Wiley Periodicals, Inc.

  3. Lagrangian postprocessing of computational hemodynamics

    PubMed Central

    Shadden, Shawn C.; Arzani, Amirhossein

    2014-01-01

    Recent advances in imaging, modeling and computing have rapidly expanded our capabilities to model hemodynamics in the large vessels (heart, arteries and veins). This data encodes a wealth of information that is often under-utilized. Modeling (and measuring) blood flow in the large vessels typically amounts to solving for the time-varying velocity field in a region of interest. Flow in the heart and larger arteries is often complex, and velocity field data provides a starting point for investigating the hemodynamics. This data can be used to perform Lagrangian particle tracking, and other Lagrangian-based postprocessing. As described herein, Lagrangian methods are necessary to understand inherently transient hemodynamic conditions from the fluid mechanics perspective, and to properly understand the biomechanical factors that lead to acute and gradual changes of vascular function and health. The goal of the present paper is to review Lagrangian methods that have been used in post-processing velocity data of cardiovascular flows. PMID:25059889

  4. An analysis of IN.PACT DEEP randomized trial on the limitations of the societal guidelines-recommended hemodynamic parameters to diagnose critical limb ischemia.

    PubMed

    Shishehbor, Mehdi H; Hammad, Tarek A; Zeller, Thomas; Baumgartner, Iris; Scheinert, Dierk; Rocha-Singh, Krishna J

    2016-05-01

    Recent small single-center data indicate that the current hemodynamic parameters used to diagnose critical limb ischemia are insensitive. We investigated the validity of the societal guidelines-recommended hemodynamic parameters against core laboratory-adjudicated angiographic data from the multicenter IN.PACT DEEP (RandomIzed AmPhirion DEEP DEB vs StAndard PTA for the treatment of below the knee Critical limb ischemia) Trial. Of the 358 patients in the IN.PACT DEEP Trial to assess drug-eluting balloon vs standard balloon angioplasty for infrapopliteal disease, 237 had isolated infrapopliteal disease with an available ankle-brachial index (ABI), and only 40 of the latter had available toe pressure measurements. The associations between ABI, ankle pressure, and toe pressure with tibial runoff, Rutherford category, and plantar arch were examined according to the cutoff points recommended by the societal guidelines. Abnormal tibial runoff was defined as severely stenotic (≥70%) or occluded and scored as one-, two-, or three-vessel disease. A stenotic or occluded plantar arch was considered abnormal. Only 14 of 237 patients (6%) had an ABI <0.4. Abnormal ankle pressure, defined as <50 mm Hg if Rutherford category 4 and <70 mm Hg if Rutherford category 5 or 6, was found only in 37 patients (16%). Abnormal toe pressure, defined as <30 mm Hg if Rutherford category 4 and <50 mm Hg if Rutherford category 5 or 6, was found in 24 of 40 patients (60%) with available measurements. Importantly, 29% of these 24 patients had an ABI within normal reference ranges. A univariate multinomial logistic regression found no association between the above hemodynamic parameters and the number of diseased infrapopliteal vessels. However, there was a significant paradoxic association where patients with Rutherford category 6 had higher ABI and ankle pressure than those with Rutherford category 5. Similarly, there was no association between ABI and pedal arch patency. The current

  5. The effect of neuraxial anesthesia on maternal cerebral hemodynamics.

    PubMed

    Postma, Ineke R; van Veen, Teelkien R; Mears, Scott L; Zeeman, Gerda G; Haeri, Sina; Belfort, Michael A

    2014-10-01

    Neuraxial anesthesia is known to reduce sympathetic tone and mean arterial pressure. Effects on cerebral hemodynamics in pregnancy are not well known. We hypothesize that cerebral hemodynamic parameters will change with respect to baseline following regional analgesia/anesthesia. We performed maternal transcranial Doppler of the middle cerebral artery in 20 women receiving epidural analgesia for labor, and 18 undergoing spinal anesthesia for cesarean section at baseline, 5 and 15 minutes. Systemic blood pressure (BP), systolic/diastolic/mean velocity, resistance and pulsatility index (PI) were recorded. Cerebral perfusion pressure, critical closing pressure (CrCP), resistance area product, and cerebral flow index were calculated. Epidural placement was associated with significant decreases in systolic/diastolic BP/mean velocity/CrCP after 15 minutes, with a corresponding increase in PI. In the spinal group, systolic/diastolic BP/mean velocity uniformly decreased and remained low after 15 minutes, and PI significantly increased and remained constant after 15 minutes. No differences were seen in BP or cerebral hemodynamics between the groups. This study demonstrates that both epidural analgesia and spinal anesthesia result in measurable cerebral hemodynamic changes in normotensive term pregnancy that are likely to be clinically insignificant as they do not affect perfusion pressure or flow. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  6. Computational simulations of hemodynamic changes within thoracic, coronary, and cerebral arteries following early wall remodeling in response to distal aortic coarctation

    PubMed Central

    Coogan, Jessica S.; Humphrey, Jay D.; Figueroa, C. Alberto

    2012-01-01

    Mounting evidence suggests that the pulsatile character of blood pressure and flow within large arteries plays a particularly important role as a mechano-biological stimulus for wall growth and remodeling. Nevertheless, understanding better the highly coupled interactions between evolving wall geometry, structure, and properties and the hemodynamics will require significantly more experimental data. Computational fluid–solid-growth models promise to aid in the design and interpretation of such experiments and to identify candidate mechanobiological mechanisms for the observed arterial adaptations. Motivated by recent aortic coarctation models in animals, we used a computational fluid–solid interaction model to study possible local and systemic effects on the hemodynamics within the thoracic aorta and coronary, carotid, and cerebral arteries due to a distal aortic coarctation and subsequent spatial variations in wall adaptation. In particular, we studied an initial stage of acute cardiac compensation (i.e., maintenance of cardiac output) followed by early arterial wall remodeling (i.e., spatially varying wall thickening and stiffening). Results suggested, for example, that while coarctation increased both the mean and pulse pressure in the proximal vessels, the locations nearest to the coarctation experienced the greatest changes in pulse pressure. In addition, after introducing a spatially varying wall adaptation, pressure, left ventricular work, and wave speed all increased. Finally, vessel wall strain similarly experienced spatial variations consistent with the degree of vascular wall adaptation. PMID:22415052

  7. A Bayesian approach to tracking patients having changing pharmacokinetic parameters

    NASA Technical Reports Server (NTRS)

    Bayard, David S.; Jelliffe, Roger W.

    2004-01-01

    This paper considers the updating of Bayesian posterior densities for pharmacokinetic models associated with patients having changing parameter values. For estimation purposes it is proposed to use the Interacting Multiple Model (IMM) estimation algorithm, which is currently a popular algorithm in the aerospace community for tracking maneuvering targets. The IMM algorithm is described, and compared to the multiple model (MM) and Maximum A-Posteriori (MAP) Bayesian estimation methods, which are presently used for posterior updating when pharmacokinetic parameters do not change. Both the MM and MAP Bayesian estimation methods are used in their sequential forms, to facilitate tracking of changing parameters. Results indicate that the IMM algorithm is well suited for tracking time-varying pharmacokinetic parameters in acutely ill and unstable patients, incurring only about half of the integrated error compared to the sequential MM and MAP methods on the same example.

  8. Influence of heart rate and atrial transport on left ventricular volume and function: relation to hemodynamic changes produced by supraventricular arrhythmia

    SciTech Connect

    Hung, J.; Kelly, D.T.; Hutton, B.F.; Uther, J.B.; Baird, D.K.

    1981-10-01

    The response of the left ventricle to pacing-induced changes in heart rate and the atrioventricular (A-V) relation was examined with equilibrium gated radionuclide ventriculography in 20 patients who had normal ventricular function after surgery for recurrent supraventricular tachycardia. In 10 patients count-derived left ventricular ejection fraction, end-diastolic volume and stroke volume were measured during sinus rhythm and during atrial pacing at 120, 140 and 160 beats/min. In the other 10 patients similar determinations were made during sequential A-V and simultaneous ventricular and atrial (V/A) pacing, both at rates of 100 and 160 beats/min. The data indicate that the hemodynamic consequences of supraventricular tachyarrhythmias in patients with normal ventricular function are due primarily to decreases in ventricular volume as heart rate is increased and atrial contribution is lost rather than to any changes in left ventricular ejection fraction.

  9. Photoresist Exposure Parameter Extraction from Refractive Index Change during Exposure

    NASA Astrophysics Data System (ADS)

    Sohn, Young-Soo; Sung, Moon-Gyu; Lee, Young-Mi; Lee, Eun-Mi; Oh, Jin-Kyung; Byun, Sung-Hwan; Jeong, Yeon-Un; Oh, Hye-Keun; An, Ilsin; Lee, Kun-Sang; Park, In-Ho; Cho, Joon-Yeon; Lee, Sang-Ho

    1998-12-01

    The refractive indices of photoresist are usually measured byan ellipsometer or spectrophotometer, but the values are limited to pre-exposure. It is known thatthe real and imaginary indices are changed during the exposure.But there is little report on these variations since itis difficult to measure this refractive index change at deep ultraviolet. The DillABC parameters show a significant variation with the resist and substrate thicknessas well as the experimental conditions.A method is suggested to extract the parameters from the refractive index changes.We can get the refractive index change and extract the Dill ABC exposure parameters from that.The multiple thin film interference calculation is used to fit the measured transmittance data.The results of our experiments and calculations for several resists including193 nm chemically amplified resists are compared with other methods.The results are agreed well with the full multilayer thin film simulation.

  10. Influence of parameter changes to stability behavior of rotors

    NASA Technical Reports Server (NTRS)

    Fritzen, C. P.; Nordmann, R.

    1982-01-01

    The occurrence of unstable vibrations in rotating machinery requires corrective measures for improvement of the stability behavior. A simple approximate method is represented to find out the influence of parameter changes to the stability behavior. The method is based on an expansion of the eigenvalues in terms of system parameters. Influence coefficients show the effect of structural modifications. The method first of all was applied to simple nonconservative rotor models. It was approved for an unsymmetric rotor of a test rig.

  11. Hemodynamic alterations in chronically conscious unrestrained diabetic rats.

    PubMed

    Carbonell, L F; Salom, M G; Garcia-Estañ, J; Salazar, F J; Ubeda, M; Quesada, T

    1987-05-01

    Important cardiovascular dysfunctions have been described in streptozotocin (STZ)-diabetic rats. To determine the influence of these changes on the hemodynamic state and whether insulin treatment can avoid them, different hemodynamic parameters, obtained by the thermodilution method, were studied in STZ-induced (65 mg/kg) diabetic male Wistar rats, as well as in age-control, weight-control, and insulin-treated diabetic ones. All rats were examined in the conscious, unrestrained state 12 wk after induction of diabetes or acidified saline (pH 4.5) injection. At 12 wk of diabetic state most important findings were normotension, high blood volume, bradycardia, increase in stroke volume, cardiac output, and cardiosomatic ratio, and decrease in total peripheral resistance and cardiac contractility and relaxation (dP/dtmax and dP/dtmin of left ventricular pressure curves). The insulin-treated diabetic rats did not show any hemodynamic differences when compared with the control animals. These results suggest that important hemodynamic alterations are present in the chronic diabetic state, possibly conditioning congestive heart failure. These alterations can be prevented by insulin treatment.

  12. Changes in quantitative ultrasound parameters during HIFU application

    NASA Astrophysics Data System (ADS)

    Ghoshal, Goutam; Kemmerer, Jeremy P.; Oelze, Michael L.

    2012-10-01

    Quantitative ultrasound (QUS) is a novel imaging technique that is hypothesized to be capable of monitoring of High Intensity Focused Ultrasound (HIFU) treatment by quantifying tissue changes during exposure. Experiments were conducted on fresh liver samples from rats and lesions were formed using a HIFU system (1-MHz, f/1.2). A wire thermocouple was inserted into the sample to monitor temperature elevation. Backscattered time domain waveforms were recorded using a clinical imaging system (Ultrasonix, L14-5 linear array) during the HIFU application and backscatter coefficients were estimated using a reference phantom technique. Two parameters were estimated from the backscatter coefficient (effective scatterer diameter (ESD) and effective acoustic concentration (EAC)) and two parameters were estimated from the envelope statistics (k parameter and μ parameter) of the backscattered echoes. At the end of the exposure the ESD, EAC and k parameters changed in the treated region by 20%, 50% and 15% respectively, compared to the untreated region. Furthermore, changes in QUS parameters followed the shape of the temperature profile recorded by the thermocouple. These results suggest that QUS techniques could be used for noninvasive thermometry of HIFU.

  13. Effect of a thin superficial layer on the estimate of hemodynamic changes in a two-layer medium by time domain NIRS

    PubMed Central

    Re, Rebecca; Contini, Davide; Zucchelli, Lucia; Torricelli, Alessandro; Spinelli, Lorenzo

    2016-01-01

    In order to study hemodynamic changes involved in muscular metabolism by means of time domain fNIRS, we need to discriminate in the measured signal contributions coming from different depths. Muscles are, in fact, typically located under other tissues, e.g. skin and fat. In this paper, we study the possibility to exploit a previously proposed method for analyzing time-resolved fNIRS measurements in a two-layer structure with a thin superficial layer. This method is based on the calculation of the time-dependent mean partial pathlengths. We validated it by simulating venous and arterial arm cuff occlusions and then applied it on in vivo measurements. PMID:26977338

  14. Characteristics of intraoperative abnormal hemodynamics during resection of an intra-fourth ventricular tumor located on the dorsal medulla oblongata.

    PubMed

    Ideguchi, Makoto; Kajiwara, Koji; Yoshikawa, Koichi; Sadahiro, Hirokazu; Nomura, Sadahiro; Fujii, Masami; Suzuki, Michiyasu

    2013-01-01

    Abnormal hemodynamics during extirpation of a para-medulla oblongata (MO) tumor is common and may be associated with direct vagal stimulation of the medullary circuit. However, resection of tumors on the dorsal MO may also induce hemodynamic instability without direct vagal stimulus. The objective of this study was to examine the characteristics of hemodynamic instability unrelated to vagal stimulus during dissection of an intra-fourth ventricular tumor with attachment to the dorsal MO. A retrospective analysis was performed in 13 patients. Abnormal hemodynamics were defined as a > 20% change from the means of the intraoperative mean arterial pressure (MAP) and heart rate (HR). Relationships of intraoperative hemodynamics were evaluated with various parameters, including the volume of the MO. Six patients (46.2%) had intraoperative hypertension during separation of the tumor bulk from the dorsal MO. The maximum MAP and HR in these patients were significantly greater than those in patients with normal hemodynamics (116.0 ± 18.0 mmHg versus 85.6 ± 6.5 mmHg; 124.3 ± 22.8 bpm versus 90.5 ± 14.7 bpm). All six cases with abnormal hemodynamics showed hemodynamic fluctuation during separation of the tumor bulk from the dorsal MO. The preoperative volume of the MO in these patients was 1.11 cc less than that in patients with normal hemodynamics, but the volume after tumor resection was similar in the two groups (5.23 cc and 5.12 cc). This suggests that the MO was compressed by the conglutinate tumor bulk, with resultant fluctuation of hemodynamics. Recognition of and preparation for this phenomenon are important for surgery on a tumor located on the dorsal MO.

  15. How to assess hemodynamic status in very preterm newborns in the first week of life?

    PubMed

    Escourrou, G; Renesme, L; Zana, E; Rideau, A; Marcoux, M O; Lopez, E; Gascoin, G; Kuhn, P; Tourneux, P; Guellec, I; Flamant, C

    2017-09-01

    Assessing hemodynamic status in preterm newborns is an essential task, as many studies have shown increased morbidity when hemodynamic parameters are abnormal. Although oscillometric monitoring of arterial blood pressure (BP) is widely used due to its simplicity and lack of side effects, these values are not always correlated with microcirculation and oxygen delivery. This review focuses on different tools for the assessment of hemodynamic status in preterm newborns. These include the measurement of clinical (BP, capillary refill time and urinary output (UO)) or biological parameters (lactate analysis), functional echocardiography, and near-infrared spectroscopy (NIRS). We describe the concepts and techniques involved in these tools in detail, and examine the interest and limitations of each type of assessment. This review highlights the complementarities between the different parameters used to assess hemodynamic status in preterm newborns during the first week of life. The analysis of arterial BP measured by oscillometric monitoring must take into account other clinical data, in particular capillary refill time and UO, and biological data such as lactate levels. Echocardiography improves noninvasive hemodynamic management in newborns but requires specific training. In contrast, NIRS may be useful in monitoring the clinical course of infants at risk of, or presenting with, hypotension. It holds the potential for early and noninvasive identification of silent hypoperfusion in critically ill preterm infants. However, more data are needed to confirm the usefulness of this promising tool in significantly changing the outcome of these infants.

  16. Hemodynamics and changes after STA-MCA anastomosis in moyamoya disease and atherosclerotic cerebrovascular disease measured by micro-Doppler ultrasonography.

    PubMed

    Morisawa, Hanako; Kawamata, Takakazu; Kawashima, Akitsugu; Hayashi, Masataka; Yamaguchi, Kohji; Yoneyama, Taku; Okada, Yoshikazu

    2013-07-01

    Moyamoya disease (MMD) and atherosclerotic cerebrovascular disease (ACVD) differ in angiographic appearance and probably hemodynamics. Pediatric MMD (PMMD) usually presents with cerebral ischemia, while intracranial hemorrhage is more common in adult MMD (AMMD), suggesting differences in cerebral hemodynamics. We analyzed the cortical flow velocity and direction of recipient arteries using micro-Doppler ultrasonography to evaluate the cortical circulation before and after anastomosis in MMD and ACVD. Twenty-eight patients with adult MMD (AMMD), 7 with pediatric MMD (PMMD), 16 with ACVD, and 12 control patients were studied. A micro-Doppler probe was applied on the cortical recipient artery (A4 or M4) before and after anastomosis. Systolic maximum flow velocity (V max) and blood flow direction were investigated at proximal and distal parts of anastomosed sites in recipient arteries. Pre- and postoperative regional cerebral blood flow was measured by cold xenon-computed tomography (Xe-CT). Before anastomosis, retrograde cortical flow was significantly more common in PMMD patients, and V max in cortical artery was significantly lower in AMMD patients. Bypass surgery changed the direction of blood flow from the anastomosis site to proximal and distal sites of the recipient artery in most patients, but pre-anastomosis flow direction was preserved more frequently in PMMD patients. The rate of V max increase after anastomosis was significantly higher in AMMD than in PMMD (11.6 ± 9.8 vs. 3.9 ± 1.8; P = 0.01). Micro-Doppler ultrasonography identified differences in cortical circulation among AMMD, PMMD, and ACVD. In AMMD, significantly low velocity in the cortical artery was observed before anastomosis, and bypass surgery reversed the flow and significantly increased flow velocity. The data of PMMD showed unique hemodynamics of the cortical artery before anastomosis, characterized by a higher frequency of retrograde flow and preserved velocity. The V max

  17. In vivo imaging of tissue scattering parameter and cerebral hemodynamics in rat brain with a digital red-green-blue camera

    NASA Astrophysics Data System (ADS)

    Nishidate, Izumi; Mustari, Afrina; Kawauchi, Satoko; Sato, Shunichi; Sato, Manabu; Kokubo, Yasuaki

    2017-02-01

    We propose a rapid imaging method to monitor the spatial distribution of total hemoglobin concentration (CHbT), the tissue oxygen saturation, and the scattering power b in the expression of μs'=aλ-b as the scattering parameters in cerebral cortex using a digital red-green-blue camera. In the method, the RGB-values are converted into the tristimulus values in CIEXYZ color space which is compatible with the common RGB working spaces. Monte Carlo simulation (MCS) for light transport in tissue is used to specify a relation among the tristimulus XYZ-values and the concentration of oxygenated hemoglobin, that of deoxygenated hemoglobin, and the scattering power b. In the present study, we performed sequential recordings of RGB images of in vivo exposed rat brain during the cortical spreading depolarization evoked by the topical application of KCl. Changes in the total hemoglobin concentration and the tissue oxygen saturation imply the temporary change in cerebral blood flow during CSD. Decrease in the scattering power b was observed before the profound increase in the total hemoglobin concentration, which is indicative of the reversible morphological changes in brain tissue during CSD. The results in this study indicate potential of the method to evaluate the pathophysiological conditions in brain tissue with a digital red-green-blue camera.

  18. Quantitative radionuclide angiography in assessment of hemodynamic changes during upright exercise: observations in normal subjects, patient with coronary artery disease and patients with aortic regurgitation

    SciTech Connect

    Iskandrian, A.S.; Hakki, A.H.; Kane, S.A.; Segal, B.L.

    1981-08-01

    Quantitative radionuclide angiography was used to evaluate hemodynamic changes in three subject groups during symptom-limited upright exercise. The 12 normal subjects had significant increases in heart rate, stroke volume, left ventricular ejection fraction and cardiac output during exercise; changes in end-diastolic and end-systolic volumes were not significant. In the 24 patients with coronary artery disease there were significant increases in heart rate and cardiac output during exercise, but insignificant changes in end-diastolic, end-systolic and stroke volumes and ejection fraction. The change in diastolic volume in these patients was determined by the extent of coronary artery disease, propranolol therapy, end point of exercise and presence of collateral vessels. Furthermore, patients with previous myocardial infarction had a lower ejection fraction and higher end-diastolic and end-systolic volumes during exercise than those without myocardial infarction. In the 12 patients with chronic aortic regurgitation of moderate to severe degree, there was a decrease in the end-diastolic volume during exercise. This response was distinctly different from that of the normal subjects or the patients with coronary artery disease. All three groups had a significant decrease in pulmonary transit time during exercise. It is concluded that changes in cardiac output in normal subjects during upright exercise are related to augmentation of stroke volume and tachycardia, whereas in patients with coronary artery disease they are related mainly to tachycardia.

  19. Cerebral hemodynamic and oxygenation changes induced by inner and heard speech: a study combining functional near-infrared spectroscopy and capnography.

    PubMed

    Scholkmann, Felix; Klein, Sabine D; Gerber, Ursina; Wolf, Martin; Wolf, Ursula

    2014-01-01

    The aim of this study was to investigate the effects of inner and heard speech on cerebral hemodynamics and oxygenation in the anterior prefrontal cortex (PFC) using functional near-infrared spectroscopy and to test whether potential effects were caused by alterations in the arterial carbon dioxide pressure (PaCO2). Twenty-nine healthy adult volunteers performed six different tasks of inner and heard speech according to a randomized crossover design. During the tasks, we generally found a decrease in PaCO2 (only for inner speech), tissue oxygen saturation (StO2), oxyhemoglobin ([O2Hb]), total hemoglobin ([tHb]) concentration and an increase in deoxyhemoglobin concentration ([HHb]). Furthermore, we found significant relations between changes in [O2Hb], [HHb], [tHb], or StO2 and the participants' age, the baseline PETCO2, or certain speech tasks. We conclude that changes in breathing during the tasks led to lower PaCO2 (hypocapnia) for inner speech. During heard speech, no significant changes in PaCO2 occurred, but the decreases in StO2, [O2Hb], and [tHb] suggest that changes in PaCO2 were also involved here. Different verse types (hexameter and alliteration) led to different changes in [tHb], implying different brain activations. In conclusion, StO2, [O2Hb], [HHb], and [tHb] are affected by interplay of both PaCO2 reactivity and functional brain activity.

  20. Measuring Hemodynamic Changes in the Ophthalmic Artery During Applied Force for Noninvasive Intracranial Pressure Monitoring: Test Results in a Porcine Model.

    PubMed

    Twedt, Max; Pfeifer, Chase; Thorell, William; Bashford, Greg

    2017-03-01

    Possible traumatic brain injury victims would greatly benefit from a handheld, noninvasive intracranial pressure (ICP) monitoring tool, which a medic could operate in a remote area. Such a device would also benefit the transport of injured soldiers during en route medical care and critical care air transport. This study demonstrates the use of noninvasive blood flow measurements in the eye by ultrasound as a proxy for ICP. ICP was artificially raised in a porcine model and resultant blood flow change in the ophthalmic artery was measured. In addition, the ultrasound transducer itself was used to compress the eye further altering ophthalmic hemodynamics. Blood flow velocities at a range of applied forces and ICP were compared. It was found that 3.25 N of force applied to the cornea was sufficient to produce significant changes in ophthalmic artery blood dynamics regardless of the ICP value. Specifically, the change in resistivity index (RI) and pulsatility index (PI) as force was applied to the cornea correlated with ICP levels. In multiple animal experiments, the magnitude of PI/RI percent change was inversely related to differences in ICP. Force applied to the cornea at baseline ICP resulted in a 15% increase in PI/RI. Results indicate that as ICP increases, the percent change in PI/RI while force is applied decreases. The consistency of data collected indicates that a trend line developed with this data and from similar experiments could be used as a predictive measurement of ICP.

  1. Transmission, Acquisition, Parameter-Setting, Reanalysis, and Language Change

    ERIC Educational Resources Information Center

    Mufwene, Salikoko S.

    2011-01-01

    Jurgen Meisel's (JM) article is literally thought-provoking, especially for the issues that one can raise out of the central position that he develops, viz., "although bilingual acquisition in situations of language contact can be argued to be of significant importance for explanations of grammatical change, reanalysis affecting parameter settings…

  2. Changes in hemodynamics and tissue oxygenation saturation in the brain and skeletal muscle induced by speech therapy - a near-infrared spectroscopy study.

    PubMed

    Wolf, U; Scholkmann, F; Rosenberger, R; Wolf, M; Nelle, M

    2011-06-09

    Arts speech therapy (AST) is a therapeutic method within complementary medicine and has been practiced for decades for various medical conditions. It comprises listening and the recitation of different forms of speech exercises under the guidance of a licensed speech therapist. The aim of our study was to noninvasively investigate whether different types of recitation influence hemodynamics and oxygenation in the brain and skeletal leg muscle using near-infrared spectroscopy (NIRS). Seventeen healthy volunteers (eight men and nine women, mean age ± standard deviation 35.6 ± 12.7 years) were enrolled in the study. Each subject was measured three times on different days with the different types of recitation: hexameter, alliteration, and prose verse. Before, during, and after recitation, relative concentration changes of oxyhemoglobin (Δ[O2Hb]), deoxyhemoglobin (Δ[HHb]), total hemoglobin (Δ[tHb]), and tissue oxygenation saturation (StO2) were measured in the brain and skeletal leg muscle using a NIRS device. The study was performed with a randomized crossover design. Significant concentration changes were found during recitation of all verses, with mainly a decrease in Δ[O2Hb] and ΔStO2 in the brain, and an increase in Δ[O2Hb] and Δ[tHb] in the leg muscle during recitation. After the recitations, significant changes were mainly increases of Δ[HHb] and Δ[tHb] in the calf muscle. The Mayer wave spectral power (MWP) was also significantly affected, i.e., mainly the MWP of the Δ[O2Hb] and Δ[tHb] increased in the brain during recitation of hexameter and prose verse. The changes in MWP were also significantly different between hexameter and alliteration, and hexameter and prose. Possible physiological explanations for these changes are discussed. A probable reason is a different effect of recitations on the sympathetic nervous system. In conclusion, these changes show that AST has relevant effects on the hemodynamics and oxygenation of the brain and muscle.

  3. The effects of housing conditions on baseline cardiovascular parameters and the sensitivity to detect changes in contractility in telemetry-implanted dogs.

    PubMed

    Sadekova, Nataliya; Boudreau, Ghislaine; Jalbert, Benoit; Norton, Kevin

    2016-01-01

    There is a growing weight of evidence to suggest that myocardial contractility is an important parameter to assess as part of IND enabling studies in addition to standard assessments as per the ICH S7A and S7B guidelines. Historically, assessments of contractility have been limited to snap-shot echocardiography or single housed telemetry assessments of left ventricular pressure. There is a growing number of studies showing that social housing conditions in large animals are beneficial, do not impact the integrity of the data collected and improve animal welfare. With current advances in cardiovascular technology it is now feasible to conduct cardiovascular assessments under group housing conditions. Therefore, the purpose of this study was to evaluate baseline hemodynamic parameters, within a group housed environment, and to demonstrate that the model retains the sensitivity of the traditional assessments. Four animals were instrumented with DSI HD-L21 implants for continuous 24-hour assessment of systemic arterial pressures, left ventricular pressures, heart rate and electrocardiogram intervals in group housed conditions. The animals were administered either Atenolol (0.3, 1 and 3mg/kg), a known negative inotrope, or Pimobendan (0.1, 0.3 and 1mg/kg), a known positive inotrope. The results showed that group housing had no influence on baseline hemodynamic assessments as compared to historical data from single housed animals. The administration of Atenolol and Pimobendan induced the expected changes in cardiovascular parameters. The baseline hemodynamic parameters remained within physiological ranges and were not influenced by group housing conditions. The model retained sensitivity to detect the expected changes in contractility in line with known effects of Atenolol and Pimobendan in dogs. In conclusion, the use of social housing conditions in dogs provides an enriched environment, compliant with animal welfare recommendations, and is in line with the ICH S7A

  4. Hemodialysis causes changes in dynamic vectorcardiographic ischemia monitoring parameters.

    PubMed

    Ojanen, S; Kööbi, T; Koivisto, A M; Korhonen, P; Mustonen, J; Pasternack, A

    2000-09-01

    The aim of this study was to establish whether changes in parameters reflecting myocardial ischemia QRS vector difference (QRS-VD), ST change vector magnitude (STC-VM) and ST vector magnitude (ST-VM6) during hemodialysis (HD) registered by MIDA (myocardial infarction dynamic analysis) are related to changes in blood volume (BV), extracellular water (ECW) and blood biochemistry. Fifteen hemodialysis (HD) patients were studied. Computerized vectorcardiography was used for on-line dynamic analysis of ST segment and QRS complex changes. BV changes were monitored non-invasively and continuously with the CRIT-LINE instrument. Bioelectric impedance analysis (BIA) was used for ECW estimation. Blood samples were taken before and after hemodialysis for hemoglobin (B-Hb), hematocrit (B-Hcr), sodium (P-Na), chloride (P-Cl), magnesium (P-Mg), potassium (P-K), ionized calcium (P-iCa), phosphate (P-Pi) and astrup measurement. During dialysis treatment QRS-VD, ST-VM6 and STC-VM did not change in parallel. According to the linear mixed model, no statistically significant changes were noted in ST-VM6 during dialysis (time effect p = 0.5635). On the other hand, QRS-VD and STC-VM showed a statistically significant linear trend (time effect for QRS-VD p = 0.0001 and for STC-VM p = 0.0004). Changes in both ECW and BV affected the change in QRS-VD and in STC-VM. During HD treatment changes in the vectorcardiographic ischemia monitoring parameters QRS-VD and STC-VM are mostly related to ECW and BV changes and may give a false positive impression of myocardial ischemia. The ST-VM6 trend is less markedly influenced by volume changes.

  5. Climate change decision-making: Model & parameter uncertainties explored

    SciTech Connect

    Dowlatabadi, H.; Kandlikar, M.; Linville, C.

    1995-12-31

    A critical aspect of climate change decision-making is uncertainties in current understanding of the socioeconomic, climatic and biogeochemical processes involved. Decision-making processes are much better informed if these uncertainties are characterized and their implications understood. Quantitative analysis of these uncertainties serve to inform decision makers about the likely outcome of policy initiatives, and help set priorities for research so that outcome ambiguities faced by the decision-makers are reduced. A family of integrated assessment models of climate change have been developed at Carnegie Mellon. These models are distinguished from other integrated assessment efforts in that they were designed from the outset to characterize and propagate parameter, model, value, and decision-rule uncertainties. The most recent of these models is ICAM 2.1. This model includes representation of the processes of demographics, economic activity, emissions, atmospheric chemistry, climate and sea level change and impacts from these changes and policies for emissions mitigation, and adaptation to change. The model has over 800 objects of which about one half are used to represent uncertainty. In this paper we show, that when considering parameter uncertainties, the relative contribution of climatic uncertainties are most important, followed by uncertainties in damage calculations, economic uncertainties and direct aerosol forcing uncertainties. When considering model structure uncertainties we find that the choice of policy is often dominated by model structure choice, rather than parameter uncertainties.

  6. INSD-Hemodynamics

    NASA Technical Reports Server (NTRS)

    Cetin, Kiris

    2004-01-01

    Hemodynamics (potentially will support Digital Astronaut program): Hemodynamics (potentially will support Digital Astronaut program): During long-duration space missions, astronauts have to adapt themselves to.altered circumstance of microgravity. Blood circulation undergoes significant adaptation during and after space flight. The blood flow through an anatomical Circle of Willis configuration is simulated to provide means for studying gravitational effects on the brain circulation.

  7. Sample size planning for longitudinal models: accuracy in parameter estimation for polynomial change parameters.

    PubMed

    Kelley, Ken; Rausch, Joseph R

    2011-12-01

    Longitudinal studies are necessary to examine individual change over time, with group status often being an important variable in explaining some individual differences in change. Although sample size planning for longitudinal studies has focused on statistical power, recent calls for effect sizes and their corresponding confidence intervals underscore the importance of obtaining sufficiently accurate estimates of group differences in change. We derived expressions that allow researchers to plan sample size to achieve the desired confidence interval width for group differences in change for orthogonal polynomial change parameters. The approaches developed provide the expected confidence interval width to be sufficiently narrow, with an extension that allows some specified degree of assurance (e.g., 99%) that the confidence interval will be sufficiently narrow. We make computer routines freely available, so that the methods developed can be used by researchers immediately.

  8. [Pulmonary hemodynamics and hemostasis in rabbits exposed to high altitude].

    PubMed

    Almerekova, A A; Tartakovskiĭ, V N; Isakova, Zh T

    1993-01-01

    Pulmonary hemodynamics, homeostasis and red blood parameters were studied in 77 rabbits in the mountains of the Tien Shan (3200 m above sea-level). Exposure of animals in alpine environment gave rise to pulmonary hypertension, polycythemia, alterations of homeostasis by the pattern of hyper- and hypocoagulation syndrome. On certain stages of adaptation products of paracoagulation were observed in blood as well as intravascular aggregation of formed elements, increased sensitivity of blood plates to platelet activation, increased fibrinolysis. Given existing hypothesis about involvement of changes in homeostasis and red blood in the pathogenesis of altitude pulmonary hypertension, the coefficients of paired linear correlation between indices of pulmonary hemodynamics and blood have been calculated. These coefficients are valid only for low values of the ratio.

  9. Comparison of Effects of Separate and Combined Sugammadex and Lipid Emulsion Administration on Hemodynamic Parameters and Survival in a Rat Model of Verapamil Toxicity.

    PubMed

    Tulgar, Serkan; Kose, Halil Cihan; Demir Piroglu, Isılay; Karakilic, Evvah; Ates, Nagihan Gozde; Demir, Ahmet; Gergerli, Ruken; Guven, Selin; Piroglu, Mustafa Devrim

    2016-03-25

    Toxicity of calcium channel blockers leads to high patient mortality and there is no effective antidote. The benefit of using 20% lipid emulsion and sugammadex has been reported. The present study measured the effect of sugammadex and 20% lipid emulsion on hemodynamics and survival in a rat model of verapamil toxicity. In this single-blinded randomized control study, rats were separated into 4 groups of 7 rats each: Sugammadex (S), Sugammadex plus 20% lipid emulsion (SL), 20% lipid emulsion (L), and control (C). Heart rates and mean arterial pressures were monitored and noted each minute until death. Average time to death was 21.0±9.57 minutes for group C, 35.57±10.61 minutes for group S, 37.14±16.6 minutes for group L and 49.86±27.56 minutes for group SL. Time to death was significantly longer in other groups than in the control group (p<0.05). Verapamil overdose is has a comparatively high mortality rate and there is no effective antidote. Treatment generally involves gastric decontamination and symptomatic treatment to counteract the drug's negative effects. In animal studies sugammadex and lipid emulsion had a positive effect on survival in patients with calcium channel blocker toxicity. Sugammadex and intralipid increased survival in a rat model of verapamil toxicity. The combination of both drugs may decrease cardiotoxicity. Sugammadex alone or combined with 20% lipid emulsion reduce the need for inotropic agents. The mechanism requires clarification with larger studies.

  10. Effects of low-dose tolvaptan on electrolyte abnormality and hemodynamic parameters in a liver cirrhosis-associated portopulmonary hypertension patient: A case report

    PubMed Central

    Ogihara, Yoshito; Yamada, Norikazu; Dohi, Kaoru; Matsuda, Akimasa; Ota, Satoshi; Ishikura, Ken; Nakamura, Mashio; Ito, Masaaki

    2017-01-01

    The present study reported a case of portopulmonary hypertension (POPH) that was secondary to underlying liver cirrhosis in a 58-year-old woman, who was successfully treated with low-dose tolvaptan. The patient had suffered from refractory peripheral edema and electrolyte abnormalities, including severe hypokalemia, under the combination therapy of sildenafil, ambrisentan, furosemide and spironolactone. Subsequent to the initiation of low-dose tolvaptan at 3.75 mg/day with concurrent de-escalation of the dose of furosemide, the daily urine volume increased, peripheral edema improved and the serum potassium level increased immediately. In addition, plasma renin activity, plasma aldosterone concentration and plasma brain natriuretic peptide level decreased within 1 week after the initiation of tolvaptan therapy. Hemodynamic assessments using a right heart catheter revealed that the pulmonary vascular resistance decreased by ~20%. Finally, chronic combination therapy with spironolactone and low-dose tolvaptan without loop diuretics achieved adequate fluid management. In conclusion, the findings of the present study suggest that low-dose tolvaptan may be a promising therapeutic option for liver cirrhosis-associated POPH in patients with an electrolyte abnormality due to liver cirrhosis and conventional diuretics. PMID:28123500

  11. Changes in biochemical and functional parameters for men during exercise

    PubMed Central

    Karanauskiene, Diana; Zaicenkoviene, Kristina; Stasiule, Loreta

    2015-01-01

    Benefits of physical activity are undeniable. The aim of the present research was to determine the effects of physical activity and age on cholesterol and glucose levels in the blood, as well as changes in the functional parameters of the cardiovascular system, during stepwise increases in physical load for men employed in the same place, but with different levels of physical activity. The subjects were 95 military officers who were divided into groups according to the level of physical activity of their occupation, with veloergometry used as physical load. Cholesterol and glucose levels in the blood were taken as biochemical indices. The results showed that occupational physical activity had a positive effect on biochemical and cardiovascular functional parameters before, during, and after the physical load. Only the cardiovascular rate (systolic blood pressure) in older subjects was significantly higher than that of the younger persons; for all other parameters, age had no effect at all. PMID:28352696

  12. Inverse sequential detection of parameter changes in developing time series

    NASA Technical Reports Server (NTRS)

    Radok, Uwe; Brown, Timothy J.

    1992-01-01

    Progressive values of two probabilities are obtained for parameter estimates derived from an existing set of values and from the same set enlarged by one or more new values, respectively. One probability is that of erroneously preferring the second of these estimates for the existing data ('type 1 error'), while the second probability is that of erroneously accepting their estimates for the enlarged test ('type 2 error'). A more stable combined 'no change' probability which always falls between 0.5 and 0 is derived from the (logarithmic) width of the uncertainty region of an equivalent 'inverted' sequential probability ratio test (SPRT, Wald 1945) in which the error probabilities are calculated rather than prescribed. A parameter change is indicated when the compound probability undergoes a progressive decrease. The test is explicitly formulated and exemplified for Gaussian samples.

  13. An Exploration of the Effect of Hemodynamic Changes Due to Normal Aging on the fNIRS Response to Semantic Processing of Words

    PubMed Central

    Amiri, Mahnoush; Pouliot, Philippe; Bonnéry, Clément; Leclerc, Paul-Olivier; Desjardins, Michèle; Lesage, Frédéric; Joanette, Yves

    2014-01-01

    Like other neuroimaging techniques assessing cerebral blood oxygenation, near-infrared spectroscopy (NIRS) has been applied in many neurocognitive studies. With NIRS, neural activation can be explored indirectly via hemodynamic changes in the imaged region. In studies of aging, changes in baseline physiology and brain anatomy confound NIRS measures seeking to investigate age-related changes in neuronal activity. The field is thus hampered by the complexity of the aging process itself, and statistical inferences from functional data acquired by optical imaging techniques must be interpreted with care. Multimodal integration of NIRS with both structural and baseline physiological assessments is crucial to avoid misinterpreting neuroimaging signals. In this study, a combination of two different optical techniques, anatomical MRI and Arterial Spin Labeling (ASL), was used to investigate age-related changes in activation during a lexical-semantic processing task. Quantitative analysis revealed decreased baseline oxyhemoglobin and cerebral blood flow in the older adults. Using baseline physiology measures as regressors in the investigation of functional concentration changes when doing analyses of variance, we found significant changes in task-induced areas of activity. In the right hemisphere, more significant age-related activity was observed around the junction of the inferior frontal gyrus and inferior precentral sulcus, along with engagement of Wernicke’s area. In the left hemisphere, the degree and extent of frontal activation, including the dorsolateral prefrontal cortex and inferior frontal gyrus, differed between age groups. Measuring background physiological differences and using their values as regressors in statistical analyses allowed a more appropriate, age-corrected understanding of the functional differentiations between age groups. Age-corrected baselines are thus essential to investigate which components of the NIRS signal are altered by aging. PMID

  14. Functional hemodynamic monitoring.

    PubMed

    Pinsky, Michael R

    2015-01-01

    Functional hemodynamic monitoring is the assessment of the dynamic interactions of hemodynamic variables in response to a defined perturbation. Recent interest in functional hemodynamic monitoring for the bedside assessment of cardiovascular insufficiency has heightened with the documentation of its accuracy in predicting volume responsiveness using a wide variety of monitoring devices, both invasive and noninvasive, and across multiple patient groups and clinical conditions. However, volume responsiveness, though important, reflects only part of the overall spectrum of functional physiologic variables that can be measured to define the physiologic state and monitor response to therapy. Copyright © 2015 Elsevier Inc. All rights reserved.

  15. Hemodynamic Changes Following Visual Stimulation and Breath-holding Provide Evidence for an Uncoupling of Cerebral Blood Flow and Volume from Oxygen Metabolism

    PubMed Central

    Donahue, Manus J.; Stevens, Robert D.; de Boorder, Michiel; Pekar, James J.; Hendrikse, Jeroen; van Zijl, Peter C.M.

    2010-01-01

    Functional neuroimaging is most commonly performed using the blood-oxygenation-level-depend (BOLD) approach, which is sensitive to changes in cerebral blood flow (CBF), cerebral blood volume (CBV), and the cerebral metabolic rate of oxygen (CMRO2). However, the precise mechanism by which neuronal activity elicits a hemodynamic response remains controversial. Here, separate visual stimulation (14s flashing checkerboard) and breath-hold (4s exhale + 14s breath-hold) experiments were performed in parallel on healthy volunteers using BOLD, CBV-weighted (CBVw) and CBF-weighted (CBFw) fMRI. Following visual stimulation, the BOLD signal persisted for 33±5s (n=9) and was bi-phasic with a negative component (undershoot), whereas CBV and CBF returned to baseline without an undershoot at 20±5s and 20±3s, respectively. Following breath-hold, the BOLD signal returned to baseline (23±7s) at the same time (p>0.05) as CBV (21±6s) and CBF (18±3s), without a post-stimulus undershoot. These data indicate that following visual activation, the BOLD undershoot is likely due to continued elevated CMRO2. Furthermore, persisting elevated CMRO2 is found when CBF and CBV have returned to baseline levels, providing evidence for an uncoupling of CBV and CBF responses from CMRO2 changes. Persisting elevated CMRO2 following elevated neuronal activity may be necessary to reverse neurotransmitter movements arising from excitatory postsynaptic currents. PMID:18797471

  16. Comparison of Effects of Separate and Combined Sugammadex and Lipid Emulsion Administration on Hemodynamic Parameters and Survival in a Rat Model of Verapamil Toxicity

    PubMed Central

    Tulgar, Serkan; Kose, Halil Cihan; Piroglu, Isılay Demir; Karakilic, Evvah; Ates, Nagihan Gozde; Demir, Ahmet; Gergerli, Ruken; Guven, Selin; Piroglu, Mustafa Devrim

    2016-01-01

    Background Toxicity of calcium channel blockers leads to high patient mortality and there is no effective antidote. The benefit of using 20% lipid emulsion and sugammadex has been reported. The present study measured the effect of sugammadex and 20% lipid emulsion on hemodynamics and survival in a rat model of verapamil toxicity. Material/Methods In this single-blinded randomized control study, rats were separated into 4 groups of 7 rats each: Sugammadex (S), Sugammadex plus 20% lipid emulsion (SL), 20% lipid emulsion (L), and control (C). Heart rates and mean arterial pressures were monitored and noted each minute until death. Results Average time to death was 21.0±9.57 minutes for group C, 35.57±10.61 minutes for group S, 37.14±16.6 minutes for group L and 49.86±27.56 minutes for group SL. Time to death was significantly longer in other groups than in the control group (p<0.05). Conclusions Verapamil overdose is has a comparatively high mortality rate and there is no effective antidote. Treatment generally involves gastric decontamination and symptomatic treatment to counteract the drug’s negative effects. In animal studies sugammadex and lipid emulsion had a positive effect on survival in patients with calcium channel blocker toxicity. Sugammadex and intralipid increased survival in a rat model of verapamil toxicity. The combination of both drugs may decrease cardiotoxicity. Sugammadex alone or combined with 20% lipid emulsion reduce the need for inotropic agents. The mechanism requires clarification with larger studies. PMID:27012816

  17. Genome-wide linkage analysis of hemodynamic parameters under mental and physical stress in extended Omani Arab pedigrees: the Oman Family Study.

    PubMed

    Hassan, Mohammed O; Jaju, Deepali; Voruganti, V Saroja; Bayoumi, Riad A; Albarwani, Sulayma; Al-Yahyaee, Saeed; Aslani, Afshin; Snieder, Harold; Lopez-Alvarenga, Juan C; Al-Anqoudi, Zahir M; Alizadeh, Behrooz Z; Comuzzie, Anthony G

    2011-06-01

    We performed a genome-wide scan in a homogeneous Arab population to identify genomic regions linked to blood pressure (BP) and its intermediate phenotypes during mental and physical stress tests. The Oman Family Study subjects (N = 1277) were recruited from five extended families of ~10 generations. Hemodynamic phenotypes were computed from beat-to-beat BP, electrocardiography and impedance cardiography. Multi-point linkage was performed for resting, mental (word conflict test, WCT) and cold pressor (CPT) stress and their reactivity scores (s), using variance components decomposition-based methods implemented in SOLAR. Genome-wide scans for BP phenotypes identified quantitative trait loci (QTLs) with significant evidence of linkage on chromosomes 1 and 12 for WCT-linked cardiac output (LOD = 3.1) and systolic BP (LOD = 3.5). Evidence for suggestive linkage for WCT was found on chromosomes 3, 17 and 1 for heart rate (LOD = 2.3), DBP (LOD = 2.4) and left ventricular ejection time (LVET), respectively. For △WCT, suggestive QTLs were detected for CO on chr11 (LOD = 2.5), LVET on chr3 (LOD = 2.0) and EDI on chr9 (LOD = 2.1). For CPT, suggestive QTLs for HR and LVET shared the same region on chr22 (LOD 2.3 and 2.8, respectively) and on chr9 (LOD = 2.3) for SBP, chr7 (LOD = 2.4) for SV and chr19 (LOD = 2.6) for CO. For △CPT, CO and TPR top signals were detected on chr15 and 10 (LOD; 2.40, 2.08) respectively. Mental stress revealed the largest number of significant and suggestive loci for normal BP reported to date. The study of BP and its intermediate phenotypes under mental and physical stress may help reveal the genes involved in the pathogenesis of essential hypertension.

  18. Changes of Probability Distributions in Tsunami Heights with Fault Parameters

    NASA Astrophysics Data System (ADS)

    Kim, Kwan-Hyuck; Kwon, Hyun-Han; Park, Yong Sung; Cho, Yong-Sik

    2017-04-01

    This study explored the changes of the probability distribution in tsunami heights along the eastern coastline of the Korea for virtual earthquakes. The results confirmed that the changes of the probability distribution in tsunami heights depending on tsunami fault parameters was found. A statistical model was developed in order to jointly analyse tsunami heights on a variety of events by regarding the functional relationships; the parameters in a Weibull distribution with earthquake characteristics could be estimated, all within a Bayesian regression framework. The proposed model could be effective and informative for the estimation of tsunami risk from an earthquake of a given magnitude at a particular location. Definitely, the coefficient of determination between the true and estimated values for Weibull distribution parameters were over 90% for both virtual and historical tsunami. Keywords: Tsunami heights, Bayesian model, Regression analysis, Risk analysis Acknowledgements This research was supported by a grant from Study on Solitary Wave Run-up for Hazard Mitigation of Coastal Communities against Sea Level Rise Project[No. 20140437] funded by Korea Institute of Marine Science and Technology promotion.

  19. Dynamic cerebral autoregulation measured with coherent hemodynamics spectroscopy (CHS)

    NASA Astrophysics Data System (ADS)

    Kainerstorfer, Jana M.; Sassaroli, Angelo; Tgavalekos, Kristen T.; Fantini, Sergio

    2015-03-01

    Coherent Hemodynamics Spectroscopy (CHS) is a novel technique for non-invasive measurements of local microcirculation quantities such as the capillary blood transit times and dynamic autoregulation. The basis of CHS is to measure, for instance with near-infrared spectroscopy (NIRS), peripheral coherent hemodynamic changes that are induced by controlled perturbations in the systemic mean arterial pressure (MAP). In this study, the MAP perturbation was induced by the fast release of two pneumatic cuffs placed around the subject's thighs after they were kept inflated (at 200 mmHg) for two minutes. The resulting transient changes in cerebral oxy- (O) and deoxy- (D) hemoglobin concentrations measured with NIRS on the prefrontal cortex are then described by a novel hemodynamic model, from which quantifiable parameters such as the capillary blood transit time and a cutoff frequency for cerebral autoregulation are obtained. We present results on eleven healthy volunteers in a protocol involving measurements during normal breathing and during hyperventilation, which is known to cause a hypocapnia-induced increase in cerebral autoregulation. The measured capillary transit time was unaffected by hyperventilation (normal breathing: 1.1±0.1 s; hyperventilation: 1.1±0.1 s), whereas the cutoff frequency of autoregulation, which increases for higher autoregulation efficiency, was indeed found to be significantly greater during hyperventilation (normal breathing: 0.017±0.002 Hz; hyperventilation: 0.034±0.005 Hz). These results provide a validation of local cerebral autoregulation measurements with the new technique of CHS.

  20. Simultaneous measurement of hemorheological and hemodynamic properties using a rat extracorporeal model

    NASA Astrophysics Data System (ADS)

    Yeom, Eunseop; Lee, Sang Joon; CenterBiofluid; Biomimetics Research Team

    2015-11-01

    It is well known that cardiovascular diseases (CVDs) are closely related with the variations of hemorheological and hemodynamic properties. Accurate measurement of these properties is essential for early diagnosis of CVDs. However, in vitro measurements have technical limitation for the accurate measurement because in vitro exposure can change hemorheological properties. To resolve this problem, a rat extracorporeal model which connects the artery and vein in a rat was employed in this study. Blood flows in the rat extracorporeal model were visualized by an ultrasound imaging system and microfluidic devices for monitoring hemorheological and hemodynamic properties. As a result, the system can be effectively used to measure blood viscosity, red blood cell aggregation and flow rate under ex vivo conditions. The present results would be helpful to develop a diagnostic modality for monitoring the variations in hemorheological and hemodynamic parameters. This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea Government (MSIP) (No. 2008-0061991).

  1. The impact of deformation of an aneurysm model under pulsatile flow on hemodynamic analysis.

    PubMed

    Kawakami, T; Takao, H; Ichikawa, C; Kamiya, K; Murayama, Y; Motosuke, M

    2016-08-01

    Hemodynamic analysis of cerebral aneurysms has been widely carried out to clarify the mechanisms of their growth and rupture. In several cases, patient-specific aneurysm models made of transparent polymers have been used. Even though periodic changes in aneurysms due to the pulsation of blood flow could be important, the deformation of the model geometry and its effect on hemodynamic evaluation has not been fully investigated. In addition, the fabrication accuracy of aneurysm models has not been evaluated even though it may affect the hemodynamic parameters to be analyzed. In this study, the fabrication accuracy of a silicone aneurysm model was investigated. Additionally, the deformation of the model under pulsatile flow as well as its correlation with flow behavior was evaluated. Consequently, a fabrication method for an aneurysm model with high accuracy was established and the importance of the wall thickness of the model was also specified.

  2. Heavy ion induced changes in small intestinal parameters

    NASA Astrophysics Data System (ADS)

    Carr, K. E.; McCullough, J. S.; Brennan, P.; Hayes, T. L.; Ainsworth, E. J.; Nelson, A. C.

    1994-10-01

    The effects on 17 different structural parameters of mouse small intestine three days after treatment with three types of heavy ion (neon, iron and niobium) are compared, the first two being of particular relevance to space flight. The data for niobium are given in full, showing that changes after niobium ion treatment are not standard and are concentrated in the epithelial compartment, with few of the parameters having a response which is dose dependent. When comparisons are made for the three types of heavy ion, the damage is greatest after neon ion irradiation, implying that the additional non-epithelial damage produced as LET rises from X rays through neutrons to neon ions is not necessarily maintained as LET continues to rise. Further understanding is therefore needed of the balance between changes affecting the vascular and absorptive components of the organ. Variation from group to group is also important, as is variation of strain or gastrointestinal status. All such factors are important in the understanding of changes in multicellular organs after exposure to heavy ion radiation.

  3. Metabolic changes assessed by MRS accurately reflect brain function during drug-induced epilepsy in mice in contrast to fMRI-based hemodynamic readouts.

    PubMed

    Seuwen, Aline; Schroeter, Aileen; Grandjean, Joanes; Rudin, Markus

    2015-10-15

    Functional proton magnetic resonance spectroscopy (1H-MRS) enables the non-invasive assessment of neural activity by measuring signals arising from endogenous metabolites in a time resolved manner. Proof-of-principle of this approach has been demonstrated in humans and rats; yet functional 1H-MRS has not been applied in mice so far, although it would be of considerable interest given the many genetically engineered models of neurological disorders established in this species only. Mouse 1H-MRS is challenging as the high demands on spatial resolution typically result in long data acquisition times not commensurable with functional studies. Here, we propose an approach based on spectroscopic imaging in combination with the acquisition of the free induction decay to maximize signal intensity. Highly resolved metabolite maps have been recorded from mouse brain with 12 min temporal resolution. This enabled monitoring of metabolic changes following the administration of bicuculline, a GABA-A receptor antagonist. Changes in levels of metabolites involved in energy metabolism (lactate and phosphocreatine) and neurotransmitters (glutamate) were investigated in a region-dependent manner and shown to scale with the bicuculline dose. GABAergic inhibition induced spectral changes characteristic for increased neurotransmitter turnover and oxidative stress. In contrast to metabolic readouts, BOLD and CBV fMRI responses did not scale with the bicuculline dose indicative of the failure of neurovascular coupling. Nevertheless fMRI measurements supported the notion of increased oxidative stress revealed by functional MRS. Hence, the combined analysis of metabolic and hemodynamic changes in response to stimulation provides complementary insight into processes associated with neural activity.

  4. Development of new optical imaging systems of oxygen metabolism and simultaneous measurement in hemodynamic changes using awake mice.

    PubMed

    Takuwa, Hiroyuki; Matsuura, Tetsuya; Nishino, Asuka; Sakata, Kazumi; Tajima, Yosuke; Ito, Hiroshi

    2014-11-30

    PET allows the measurement of CBF, CBV and CMRO2 in human and plays an important role in the diagnosis of pathologic conditions and clinical research. On the other hand, in animal studies, there is no optical imaging system for evaluating changes in CBF and CBV, and oxygen metabolism, from the same brain area under awake condition. In the present study, we developed a simultaneous measurement system of LSI and IOSI, which was verified by LDF. Moreover, to evaluate oxygen metabolism, FAI was performed from the same brain area as LSI and IOSI measurements. The change in CBF according to LSI was correlated with that by LDF. Similarly, the change in CBV obtained by IOSI was also correlated with RBC concentration change measured by LDF. The change in oxygen metabolism by FAI was associated with that in CBF obtained by LSI, although the change in CBF was greater than that in oxygen metabolism. We revealed that the relationship between oxygen metabolism and CBF as measured by our system was in good agreement with the relationship between CMRO2 and CBF in human PET studies. Our measurement system of CBF, CBV and oxygen metabolism is not only useful for studying neurovascular coupling, but also easily corroborates human PET studies. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Prediction under change: invariant model parameters in a varying environment

    NASA Astrophysics Data System (ADS)

    Schymanski, S. J.; Or, D.; Roderick, M. L.; Sivapalan, M.

    2012-04-01

    Hydrological understanding is commonly synthesised into complex mechanistic models, some of which have become "as inscrutable as nature itself" (Harte, 2002). Parameters for most models are estimated from past observations. This may result in an ill-posed problem with associated "equifinality" (Beven, 1993), in which the information content in calibration data is insufficient for distinguishing a suitable parameter set among all possible sets. Consequently, we are unable to identify the "correct" parameter set that produces the right results for the right reasons. Incorporation of new process knowledge into a model adds new parameters that exacerbate the equifinality problem. Hence improved process understanding has not necessarily translated into improved models nor contributed to better predictions. Prediction under change confronts us with additional challenges: 1. Varying boundary conditions: Projections into the future can no longer be guided by observations in the past to the same degree as they could when the boundary conditions were considered stationary. 2. Ecohydrological adaptation: Common model parameters related to vegetation properties (e.g. canopy conductance, rooting depths) cannot be assumed invariant, as vegetation dynamically adapts to its environment. 3. No analog conditions for model evaluation: Climate change and in particular rising atmospheric CO2 concentrations will lead to conditions that cannot be found anywhere on Earth at present. Therefore it is doubtful whether the ability of a hydrological model to reproduce the past is indicative of its trustworthiness for predicting the future. We propose that optimality theory can help addressing some of the above challenges. Optimality theory submits that natural systems self-optimise to attain certain goal functions (or "objective functions"). Optimality principles allow an independent prediction of system properties that would otherwise require direct observations or calibration. The resulting

  6. Progressive Cortical Neuronal Damage and Chronic Hemodynamic Impairment in Atherosclerotic Major Cerebral Artery Disease.

    PubMed

    Yamauchi, Hiroshi; Kagawa, Shinya; Kishibe, Yoshihiko; Takahashi, Masaaki; Higashi, Tatsuya

    2016-06-01

    Cross-sectional studies suggest that chronic hemodynamic impairment may cause selective cortical neuronal damage in patients with atherosclerotic internal carotid artery or middle cerebral artery occlusive disease. The purpose of this longitudinal study was to determine whether the progression of cortical neuronal damage, evaluated as a decrease in central benzodiazepine receptors (BZRs), is associated with hemodynamic impairment at baseline or hemodynamic deterioration during follow-up. We evaluated the distribution of BZRs twice using positron emission tomography and (11)C-flumazenil over time in 80 medically treated patients with atherosclerotic internal carotid artery or middle cerebral artery occlusive disease that had no ischemic episodes during follow-up. Using 3D stereotactic surface projections, we quantified abnormal decreases in the BZRs in the cerebral cortex within the middle cerebral artery distribution and correlated changes in the BZR index with the mean hemispheric values of hemodynamic parameters obtained from (15)O gas positron emission tomography. In the hemisphere affected by arterial disease, the BZR index in 40 patients (50%) was increased during follow-up (mean 26±20 months). In multivariable logistic regression analyses, increases in the BZR index were associated with the decreased cerebral blood flow at baseline and an increased oxygen extraction fraction during follow-up. Increases in the oxygen extraction fraction during follow-up were associated with a lack of statin use. In patients with atherosclerotic internal carotid artery or middle cerebral artery disease, the progression of cortical neuronal damage was associated with hemodynamic impairment at baseline and hemodynamic deterioration during follow-up. Statin use may be beneficial against hemodynamic deterioration and therefore neuroprotective. © 2016 American Heart Association, Inc.

  7. Effect of postural changes on cardiovascular parameters across gender

    PubMed Central

    Patel, Kieran; Rössler, Andreas; Lackner, Helmut Karl; Trozic, Irhad; Laing, Charles; Lorr, David; Green, David A; Hinghofer-Szalkay, Helmut; Goswami, Nandu

    2016-01-01

    Abstract Introduction: We investigated the effect of postural changes on various cardiovascular parameters across gender. Twenty-eight healthy subjects (16 male, 12 female) were observed at rest (supine) and subjected to 3 interventions; head-down tilt (HDT), HDT with lower body negative pressure (HDT+ LBNP at −30 mm Hg), and head-up tilt (HUT), each for 10 minutes separated by a 10 minutes recovery period. Methods: Measurements were recorded for heart rate (HR), standard deviation of the normal-to-normal intervals, root mean square of successive differences between the normal-to-normal intervals, heart rate variability-low frequency (LFRRI), heart rate variability-high frequency (HFRRI), low frequency/high frequency ratio (LFRRI/HFRRI), systolic blood pressure (SBP), mean arterial pressure (MAP), diastolic blood pressure (DBP), total peripheral resistance index (TPRI), stroke index (SI), cardiac index (CI), index of contractility (IC), left ventricular work index, and left ventricular ejection time. Results: Across all cardiovascular parameters, there was a significant main effect of the intervention applied but there was no significant main effect of gender across all parameters. Conclusions: The results suggest that there are no specific gender differences in regards to the measured variables under the conditions of this study. Furthermore, these results suggest that in healthy subjects, there appears to be evidence that LBNP partially elicits similar cardiovascular responses to HUT, which supports the use of LBNP as an intervention to counteract the effects of central hypovolemia. PMID:27428203

  8. Association between longitudinal changes in prefrontal hemodynamic responses and social adaptation in patients with bipolar disorder and major depressive disorder.

    PubMed

    Ohtani, Toshiyuki; Nishimura, Yukika; Takahashi, Katsuyoshi; Ikeda-Sugita, Reina; Okada, Naohiro; Okazaki, Yuji

    2015-05-01

    Patients with affective disorders exhibit changes in regional brain function and show abnormal social adaptation. However, to our knowledge, no near-infrared spectroscopy (NIRS) study has examined the relationship between these two phenomena longitudinally. This study examined the region-specific functional abnormality associated with bipolar disorder (BD) and major depressive disorder (MDD), and the association between particular longitudinal changes in regional activation and social adaptation. We evaluated frontotemporal functioning during a verbal fluency test (VFT) for patients with BD (N=18), those with MDD (N=10), and healthy controls (HCs; N=14) using NIRS. NIRS measurements and the Social Adaptation Self-evaluation Scale (SASS) were administered twice with an interval of approximately 6 months. The BD and MDD groups showed lesser activation than the HCs in the bilateral ventro-lateral prefrontal cortex and the anterior part of the temporal cortex (VLPFC/aTC). Longitudinal changes in SASS scores were positively associated with the extent of change in left VLPFC/aTC activation in the BD group and with right VLPFC/aTC activation in the MDD group. Our small sample size limited statistical power, and the effect of medication and multiple comparisons cannot be excluded, although these effects were considered in the interpretation of the present results. Longitudinal increases of VLPFC/aTC activation were associated with improvement in social adaptation in patients with BD and those with MDD. NIRS measurement could be a useful tool for objective evaluation of changes in social adaptation in BD and MDD. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Acute Haemodialysis-induced Changes in Tissue Doppler Echocardiography Parameters.

    PubMed

    Sağ, Saim; Yeşilbursa, Dilek; Yıldız, Abdulmecit; Dilek, Kamil; Sentürk, Tunay; Serdar, Osman Akın; Aydınlar, Ali

    2014-09-01

    Tissue Doppler imaging (TDI) is a method that determines the tissue motion and velocity within the myocardium. To characterize acute haemodialysis (HD)-induced changes in TDI-derived indices for patients that have end-stage renal disease (ESRD). Cross sectional study. Conventional echocardiography and TDI methods were applied to study ESRD patients (n=58) before and after HD. Pulmonary venous flow, mitral inflow, and TDI signals of the lateral and septal mitral annulus were examined for the determination of altered left-ventricular diastolic filling parameters. Flow velocities from early- (E) and late-atrial (A) peak transmitral; peak pulmonary vein systolic (S) and diastolic (D); and myocardial peak systolic (Sm) and peak early (Em) and late (Am) diastolic mitral annular velocities were also assessed for changes. Transmitral E and A velocities and the E/A ratio decreased significantly after HD (p<0.001). Pulmonary vein S (p<0.001) and D (p<0.001) velocities decreased, and S/D ratios increased significantly (p=0.027). HD led to a reduction in septal Em (p<0.001), lateral Em (p=0.006), and Am (p<0.001) velocities. Contrary to the decreases in Em and Am, the Em/Am ratio remained unchanged. A single HD session was associated with an acute deterioration in the diastolic parameters. Since the Em/Am ratio remained unchanged, we conclude that this index is a relatively load-independent measure of diastolic function in HD patients.

  10. Poster — Thur Eve — 44: Linearization of Compartmental Models for More Robust Estimates of Regional Hemodynamic, Metabolic and Functional Parameters using DCE-CT/PET Imaging

    SciTech Connect

    Blais, AR; Dekaban, M; Lee, T-Y

    2014-08-15

    Quantitative analysis of dynamic positron emission tomography (PET) data usually involves minimizing a cost function with nonlinear regression, wherein the choice of starting parameter values and the presence of local minima affect the bias and variability of the estimated kinetic parameters. These nonlinear methods can also require lengthy computation time, making them unsuitable for use in clinical settings. Kinetic modeling of PET aims to estimate the rate parameter k{sub 3}, which is the binding affinity of the tracer to a biological process of interest and is highly susceptible to noise inherent in PET image acquisition. We have developed linearized kinetic models for kinetic analysis of dynamic contrast enhanced computed tomography (DCE-CT)/PET imaging, including a 2-compartment model for DCE-CT and a 3-compartment model for PET. Use of kinetic parameters estimated from DCE-CT can stabilize the kinetic analysis of dynamic PET data, allowing for more robust estimation of k{sub 3}. Furthermore, these linearized models are solved with a non-negative least squares algorithm and together they provide other advantages including: 1) only one possible solution and they do not require a choice of starting parameter values, 2) parameter estimates are comparable in accuracy to those from nonlinear models, 3) significantly reduced computational time. Our simulated data show that when blood volume and permeability are estimated with DCE-CT, the bias of k{sub 3} estimation with our linearized model is 1.97 ± 38.5% for 1,000 runs with a signal-to-noise ratio of 10. In summary, we have developed a computationally efficient technique for accurate estimation of k{sub 3} from noisy dynamic PET data.

  11. Streptozotocin-induced diabetes in the rat is associated with changes in vaginal hemodynamics, morphology and biochemical markers

    PubMed Central

    Kim, Noel N; Stankovic, Miljan; Cushman, Tulay T; Goldstein, Irwin; Munarriz, Ricardo; Traish, Abdulmaged M

    2006-01-01

    Background Diabetes is associated with declining sexual function in women. However, the effects of diabetes on genital tissue structure, innervation and function remains poorly characterized. In control and streptozotocin-treated female rats, we investigated the effects of diabetes on vaginal blood flow, tissue morphology, and expression of arginase I, endothelial nitric oxide synthase (eNOS) and cGMP-dependent protein kinase (PKG), key enzymes that regulate smooth muscle relaxation. We further related these changes with estrogen receptor alpha (ERα) and androgen receptor (AR) expression. Results In addition to significantly elevated blood glucose levels, diabetic rats had decreased mean body weight, lower levels of plasma estradiol, and higher plasma testosterone concentration, compared to age-matched controls. Eight weeks after administration of buffer (control) or 65 mg/kg of streptozotocin (diabetic), the vaginal blood flow response to pelvic nerve stimulation was significantly reduced in diabetic rats. Histological examination of vaginal tissue from diabetic animals showed reduced epithelial thickness and atrophy of the muscularis layer. Diabetic animals also had reduced vaginal levels of eNOS and arginase I, but elevated levels of PKG, as assessed by Western blot analyses. These alterations were accompanied by a reduction in both ERα and AR in nuclear extracts of vaginal tissue from diabetic animals. Conclusion In ovariectomized (estrogen deficient) animals, previous reports from our lab and others have documented changes in blood flow, tissue structure, ERα, arginase I and eNOS that parallel those observed in diabetic rats. We hypothesize that diabetes may lead to multiple disruptions in sex steroid hormone synthesis, metabolism and action. These pathological events may cause dramatic changes in tissue structure and key enzymes that regulate cell growth and smooth muscle contractility, ultimately affecting the genital response during sexual arousal. PMID

  12. Prognostic value of selected echocardiographic, impedance cardiographic, and hemodynamic parameters determined during right heart catheterization in patients qualified for heart transplantation.

    PubMed

    Gilewski, Wojciech; Pietrzak, Jarosław; Banach, Joanna; Bujak, Robert; Błażejewski, Jan; Karasek, Danuta; Wołowiec, Łukasz; Sinkiewicz, Władysław

    2017-09-22

    The aim of the study was to verify prognostic value of selected echocardiographic (UKG), impedance cardiography (ICG), and right heart catheterization (RHC) parameters in systolic heart failure (HF). UKG, ICG, and RHC were performed in 46 patients with chronic HF with ejection fraction <35%. During a 1-year follow-up, composite endpoint (death or hospitalization due to HF exacerbation) was achieved by 23 (50.0%) patients. Analysis of receiver operating characteristic (ROC) curves identified UKG parameters: inferior vena cava diameter on inspiration (IVCinsp) >13 mm [area under curve (AUC), 0.791], right atrial (RA) >5.2 cm (AUC 0.710) and ventricular dimension (RVD) >3.5 cm (AUC 0.717), tricuspid annular plane systolic excursion (TAPSE) <17 mm (AUC 0.682), and its velocity (S'RV) <6.07 cm/s (AUC 0.716) as unfavorable prognostic factors. RHC parameters: low values of cardiac index (CI < 2.1 L/min; AUC 0.846) and high pulmonary capillary wedge pressure (PCWP > 24 mmHg; AUC 0.773) turned out to be the most accurate single predictors of worse outcome. Prognostic value of non-invasive parameters was improved due to the use of their composite measures: IVC% × TAPSE (<430%/mm; AUC 0.826), RVSP/TAPSE (>2.4 mmHg/mm; AUC 0.800), IVC% × SBP (>2097% mmHg; AUC 0.826), and RA × IVCinsp/S'RV (>11.8 cm s; AUC 0.839). In conclusion, composite measures based on non-invasive parameters, such as IVC%/TAPSE, RVSP/TAPSE and RA × IVCinsp/S'RV, may provide equally accurate prognosis as the invasive examination. PCWP and CI determined during RHC were the best individual predictors of the composite endpoint. In addition, echocardiographic parameters: RVD, RA, IVC, TAPSE, and S'RV are accurate predictors of the unfavorable outcome.

  13. Stress phase angle depicts differences in coronary artery hemodynamics due to changes in flow and geometry after percutaneous coronary intervention

    PubMed Central

    Torii, Ryo; Wood, Nigel B.; Hadjiloizou, Nearchos; Dowsey, Andrew W.; Wright, Andrew R.; Hughes, Alun D.; Davies, Justin; Francis, Darrel P.; Mayet, Jamil; Yang, Guang-Zhong; Thom, Simon A. McG.; Xu, X. Yun

    2009-01-01

    The effects of changes in flow velocity waveform and arterial geometry before and after percutaneous coronary intervention (PCI) in the right coronary artery (RCA) were investigated using computational fluid dynamics. An RCA from a patient with a stenosis was reconstructed based on multislice computerized tomography images. A nonstenosed model, simulating the same RCA after PCI, was also constructed. The blood flows in the RCA models were simulated using pulsatile flow waveforms acquired with an intravascular ultrasound-Doppler probe in the RCA of a patient undergoing PCI. It was found that differences in the waveforms before and after PCI did not affect the time-averaged wall shear stress and oscillatory shear index, but the phase angle between pressure and wall shear stress on the endothelium, stress phase angle (SPA), differed markedly. The median SPA was −63.9° (range, −204° to −10.0°) for the pre-PCI state, whereas it was 10.4° (range, −71.1° to 25.4°) in the post-PCI state, i.e., more asynchronous in the pre-PCI state. SPA has been reported to influence the secretion of vasoactive molecules (e.g., nitric oxide, PGI2, and endothelin-1), and asynchronous SPA (≈−180°) is proposed to be proatherogenic. Our results suggest that differences in the pulsatile flow waveform may have an important influence on atherogenesis, although associated with only minor changes in the time-averaged wall shear stress and oscillatory shear index. SPA may be a useful indicator in predicting sites prone to atherosclerosis. PMID:19151251

  14. Early Changes in QRS Frequency Following Cardiac Resynchronization Predict Hemodynamic Response in Left Bundle Branch Block Patients.

    PubMed

    Niebauer, Mark J; Rickard, John; Tchou, Patrick J; Varma, Niraj

    2016-05-01

    QRS characteristics are the cornerstone of patient selection in cardiac resynchronization therapy (CRT) and the presence of left bundle branch block (LBBB) and baseline QRS ≥150 milliseconds portends a good outcome. We previously showed that baseline QRS frequency analysis adds predictive value to LBBB alone and have hypothesized that a change in frequency characteristics following CRT may produce additional predictive value. We examined the QRS frequency characteristics of 182 LBBB patients before and soon after CRT. Patients were assigned to responder and nonresponder groups. Responders were defined by a decrease in left ventricular end-systolic volume (LVESV) ≥15% following CRT. We analyzed the QRS in ECG leads I, AVF, and V3 before and soon after CRT using the discrete Fourier transform algorithm. The percentage of total QRS power within discrete frequency intervals before and after CRT was calculated. The reduction in lead V3 power <10 Hz was the best indicator of response. Baseline QRS width was similar between the responders and nonresponders (162.2 ± 17.2 milliseconds vs. 158 ± 22.1 milliseconds, respectively; P = 0.180). Responders exhibited a greater reduction in QRS power <10 Hz (-17.0 ± 11.9% vs. -6.6 ± 12.5%; P < 0.001) and a significant AUC (0.743; P < 0.001). A ≥8% decline in QRS power <10 Hz produced the best predictive values (PPV = 84%, NPV = 59%). Importantly, when patients with baseline QRS <150 milliseconds were compared, the AUC improved (0.892, P < 0.001). Successful CRT produces a significant reduction in QRS power below 10 Hz, particularly when baseline QRS <150 milliseconds. These results indicate that QRS frequency changes after CRT provide additional predictive value to QRS alone. © 2016 Wiley Periodicals, Inc.

  15. Changes in hemodynamic and post-flights orthostatic tolerance of cosmonauts under application of the preventive device--thigh cuffs bracelets in short-term flights.

    PubMed

    Fomina, G; Kotovskaya, A; Arbeille, F; Pochuev, V; Zhernavkov, A; Ivanovskaya, T

    2004-07-01

    to evaluate the influence of the use thigh cuffs "Bracelet" on the hemodynamic adaptation to microgravity during short-term (up to a month) space flights, in-flight tolerance to LBNP-tests and post-flight orthostatic tolerance. 6 cosmonauts applied and 7 others did not apply the occlusive cuffs when on flight. The "Bracelet" device notably relieved the cosmonauts from the subjective discomfort following by the blood redistribution at initial period of exposure to microgravity. It was established that "Bracelet" lessened shifts in central and peripheral hemodynamics typical for exposure to microgravity, venous stasis in the cervical-cephalic region in particular. There were no differences between the hemodynamic reaction on LBNP-test in cosmonauts who applied and not applied "Bracelet" during short-term flights. The objective data are received, that the application of the device during short-term space flight does not make negative effects on post-flight orthostatic tolerance.

  16. Estradiol and hemodynamics during ovulation induction.

    PubMed

    Veille, J C; Morton, M J; Burry, K; Nemeth, M; Speroff, L

    1986-09-01

    Left ventricular size and stroke volume increase in human pregnancy and during estrogen administration in laboratory animals. In order to determine if elevated levels of endogenous estrogens in humans produce hemodynamic changes similar to those that occur during pregnancy, 14 patients were studied during ovulation induction at day 8 +/- 2 (SD) (proliferative phase) and at day 14 +/- 4 (midcycle) of their cycles. M-mode echocardiography was carried out with the patient in the left lateral decubitus, head down and head up positions. The mean serum estradiol level was 294 +/- 234 (SD) pg ml-1 at day 8 +/- 2 (treatment day) and it increased to 1503 +/- 531 pg ml-1 at day 14 +/- 4 (cycle day) of the same cycle. This change in serum estradiol was significant (P less than 0.001), associated with an increase in left ventricle diastolic dimension of 2.3 +/- 1.1 mm (P less than 0.001). During the same time period stroke volume and cardiac index correspondingly increased. Heart rate, fractional shortening, and blood pressure did not change and systemic vascular resistance decreased. Many of the cardiovascular adaptations of pregnancy are duplicated by high levels of endogenous estrogens and these changes are evident in as few as 6 days. Thus, we conclude that changes in endogenous estrogen correlate with certain cardiovascular parameters, the most striking of which is the left ventricular size. This may be one of the adaptive mechanisms by which the maternal circulation adapts to pregnancy.

  17. Acute Haemodialysis-induced Changes in Tissue Doppler Echocardiography Parameters

    PubMed Central

    Sağ, Saim; Yeşilbursa, Dilek; Yıldız, Abdulmecit; Dilek, Kamil; Şentürk, Tunay; Serdar, Osman Akın; Aydınlar, Ali

    2014-01-01

    Background: Tissue Doppler imaging (TDI) is a method that determines the tissue motion and velocity within the myocardium. Aims: To characterize acute haemodialysis (HD)-induced changes in TDI-derived indices for patients that have end-stage renal disease (ESRD). Study Design: Cross sectional study. Methods: Conventional echocardiography and TDI methods were applied to study ESRD patients (n=58) before and after HD. Pulmonary venous flow, mitral inflow, and TDI signals of the lateral and septal mitral annulus were examined for the determination of altered left-ventricular diastolic filling parameters. Flow velocities from early- (E) and late-atrial (A) peak transmitral; peak pulmonary vein systolic (S) and diastolic (D); and myocardial peak systolic (Sm) and peak early (Em) and late (Am) diastolic mitral annular velocities were also assessed for changes. Results: Transmitral E and A velocities and the E/A ratio decreased significantly after HD (p<0.001). Pulmonary vein S (p<0.001) and D (p<0.001) velocities decreased, and S/D ratios increased significantly (p=0.027). HD led to a reduction in septal Em (p<0.001), lateral Em (p=0.006), and Am (p<0.001) velocities. Contrary to the decreases in Em and Am, the Em/Am ratio remained unchanged. Conclusion: A single HD session was associated with an acute deterioration in the diastolic parameters. Since the Em/Am ratio remained unchanged, we conclude that this index is a relatively load-independent measure of diastolic function in HD patients. PMID:25337420

  18. Cognition and Hemodynamics.

    PubMed

    Novak, Vera

    2012-10-01

    The relationship between cerebral hemodynamics and cognitive performance has increasingly become recognized as a major challenge in clinical practice for older adults. Both diabetes and hypertension worsen brain perfusion and are major risk factors for cerebrovascular disease, stroke and dementia. Cerebrovascular reserve has emerged as a potential biomarker for monitoring pressure-perfusion-cognition relationships. Endothelial dysfunction and inflammation, microvascular disease, and mascrovascular disease affect cerebral hemodynamics and play an important role in pathohysiology and severity of multiple medical conditions, presenting as cognitive decline in the old age. Therefore, the identification of cerebrovascular vascular reactivity as a new therapeutic target is needed for prevention of cognitive decline late in life.

  19. Cognition and Hemodynamics

    PubMed Central

    Novak, Vera

    2012-01-01

    The relationship between cerebral hemodynamics and cognitive performance has increasingly become recognized as a major challenge in clinical practice for older adults. Both diabetes and hypertension worsen brain perfusion and are major risk factors for cerebrovascular disease, stroke and dementia. Cerebrovascular reserve has emerged as a potential biomarker for monitoring pressure–perfusion–cognition relationships. Endothelial dysfunction and inflammation, microvascular disease, and mascrovascular disease affect cerebral hemodynamics and play an important role in pathohysiology and severity of multiple medical conditions, presenting as cognitive decline in the old age. Therefore, the identification of cerebrovascular vascular reactivity as a new therapeutic target is needed for prevention of cognitive decline late in life. PMID:23050027

  20. Site-specific elevation of interleukin-1β and matrix metalloproteinase-9 in the Willis circle by hemodynamic changes is associated with rupture in a novel rat cerebral aneurysm model.

    PubMed

    Miyamoto, Takeshi; Kung, David K; Kitazato, Keiko T; Yagi, Kenji; Shimada, Kenji; Tada, Yoshiteru; Korai, Masaaki; Kurashiki, Yoshitaka; Kinouchi, Tomoya; Kanematsu, Yasuhisa; Satomi, Junichiro; Hashimoto, Tomoki; Nagahiro, Shinji

    2017-08-01

    The pathogenesis of subarachnoid hemorrhage remains unclear. No models of cerebral aneurysms elicited solely by surgical procedures and diet have been established. Elsewhere we reported that only few rats in our original rat aneurysm model manifested rupture at the anterior and posterior Willis circle and that many harbored unruptured aneurysms at the anterior cerebral artery-olfactory artery bifurcation. This suggests that rupture was site-specific. To test our hypothesis that a site-specific response to hemodynamic changes is associated with aneurysmal rupture, we modified our original aneurysm model by altering the hemodynamics. During 90-day observation, the incidence of ruptured aneurysms at the anterior and posterior Willis circle was significantly increased and the high incidence of unruptured aneurysms at the anterior cerebral artery-olfactory artery persisted. This phenomenon was associated with an increase in the blood flow volume. Notably, the level of matrix metalloproteinase-9 associated with interleukin-1β was augmented by the increase in the blood flow volume, suggesting that these molecules exacerbated the vulnerability of the aneurysmal wall. The current study first demonstrates that a site-specific increase in interleukin-1β and matrix metalloproteinase-9 elicited by hemodynamic changes is associated with rupture. Our novel rat model of rupture may help to develop pharmaceutical approaches to prevent rupture.

  1. Correlation between Hemodynamics and Treatment Outcome of Intracranial Aneurysms after Intervention with Flow Diverters

    NASA Astrophysics Data System (ADS)

    Paliwal, Nikhil; Damiano, Robert; Davies, Jason; Siddiqui, Adnan; Meng, Hui

    2015-11-01

    Endovascular intervention by Flow Diverter (FD) - a densely woven stent - occludes an aneurysm by inducing thrombosis in the aneurysm sac and reconstructing the vessel. Hemodynamics plays a vital role in the thrombotic occlusion of aneurysms and eventual treatment outcome. CFD analysis of pre- and post-treatment aneurysms not only provides insight of flow modifications by FD, but also allows investigation of interventional strategies and prediction of their outcome. In this study 80 patient-specific aneurysms treated with FDs were retrospectively studied to evaluate the effect of intervention. Out of these cases, 16 required retreatment and thus are considered as having unfavorable outcome. Clinical FD deployment in these cases was simulated using an efficient virtual stenting workflow. CFD analysis was carried out on both pre- and post-treatment cases, and changes in hemodynamic parameters were calculated. Support vector machine algorithm was used to correlate the hemodynamic changes with outcome. Results show that cases having higher flow reduction into the aneurysmal sac have a better likelihood of occlusion. This suggests that changes in hemodynamics can be potentially used to predict the outcome of different clinical intervention strategies in aneurysms. This work was supported by the National Institutes of Health (R01 NS091075).

  2. Timing of fluid resuscitation shapes the hemodynamic response to uncontrolled hemorrhage: analysis using dynamic modeling.

    PubMed

    Hirshberg, Asher; Hoyt, David B; Mattox, Kenneth L

    2006-06-01

    Timing of fluid resuscitation with respect to intrinsic hemostasis is an unexplored aspect of uncontrolled hemorrhage, because most animal models do not allow direct monitoring of blood loss. The aim of this study was to define how timing of crystalloid administration affects the bleeding patient's hemodynamic response to fluids, using a computer model of blood volume changes during uncontrolled hemorrhage. A multi-compartment lumped-parameter deterministic model of intravascular volume changes in a bleeding adult patient was developed and implemented. The model incorporates empirical mathematical descriptions of intrinsic hemostasis and rebleeding. The predicted hemodynamic response to uncontrolled hemorrhage closely corresponds to that seen in animal studies. A 2-L crystalloid bolus given during ongoing hemorrhage increases blood loss by 4 to 29%, an effect that is inversely related to the initial bleeding rate. A similar bolus given after intrinsic hemostasis may trigger rebleeding if given when the hemostatic clot is mechanically vulnerable. This period of clot vulnerability (ranging from 0-34 minutes) changes with both the initial bleeding rate and the rate of fluid administration. The timing of crystalloid administration with respect to intrinsic hemostasis shapes the bleeding patient's hemodynamic response. An early bolus delays hemostasis and increases blood loss, while a late bolus may trigger rebleeding. These observations provide valuable insight into the hemodynamic response to fluid resuscitation.

  3. Seasonal changes in magnetic parameters of sediments with changing redox conditions in Hiroshima Bay, Japan

    NASA Astrophysics Data System (ADS)

    Kawamura, Noriko; Amano, Yuka; Ishikawa, Naoto

    2016-07-01

    To describe and interpret the relationship between spatial and seasonal changes in the sedimentary environment of nearshore sediments and their magnetic properties, magnetic and geochemical analyses were performed on sediment samples from three stations in Hiroshima Bay, Japan. Vertical stratification of the water column in the bay changes throughout the year, and magnetic hysteresis parameters and mineralogy in the bay sediments vary in response to changes in redox conditions of bottom waters. Magnetite and hematite are present year-round at all stations. The presence of maghemitized magnetite is inferred at a station located at the entrance to the bay. Greigite is recognized at all stations in September 2011 but is not found at the entrance to the bay when water column stratification is disturbed from October 2011. The presence of maghemite and goethite is inferred at two stations in the inner bay when the sedimentary environment is oxic. The remanent coercivity/coercivity ratio (Hcr/Hc) also varies, both spatially and temporally, which reflects changes in magnetic mineralogy. Increased of Hcr/Hc values are likely to be caused by goethite and/or maghemite formation when water column stratification is disturbed and the seafloor is oxic. Concentration-dependent magnetic parameters do not respond to seasonal changes in the redox conditions of bottom waters. Reaction times and/or changes in chemical and physical conditions may be insufficient to affect these parameters in the sediments of Hiroshima Bay.

  4. Measurement methods and accuracy analysis of Chang'E-5 Panoramic Camera installation parameters

    NASA Astrophysics Data System (ADS)

    Yan, Wei; Ren, Xin; Liu, Jianjun; Tan, Xu; Wang, Wenrui; Chen, Wangli; Zhang, Xiaoxia; Li, Chunlai

    2016-04-01

    Chang'E-5 (CE-5) is a lunar probe for the third phase of China Lunar Exploration Project (CLEP), whose main scientific objectives are to implement lunar surface sampling and to return the samples back to the Earth. To achieve these goals, investigation of lunar surface topography and geological structure within sampling area seems to be extremely important. The Panoramic Camera (PCAM) is one of the payloads mounted on CE-5 lander. It consists of two optical systems which installed on a camera rotating platform. Optical images of sampling area can be obtained by PCAM in the form of a two-dimensional image and a stereo images pair can be formed by left and right PCAM images. Then lunar terrain can be reconstructed based on photogrammetry. Installation parameters of PCAM with respect to CE-5 lander are critical for the calculation of exterior orientation elements (EO) of PCAM images, which is used for lunar terrain reconstruction. In this paper, types of PCAM installation parameters and coordinate systems involved are defined. Measurement methods combining camera images and optical coordinate observations are studied for this work. Then research contents such as observation program and specific solution methods of installation parameters are introduced. Parametric solution accuracy is analyzed according to observations obtained by PCAM scientifically validated experiment, which is used to test the authenticity of PCAM detection process, ground data processing methods, product quality and so on. Analysis results show that the accuracy of the installation parameters affects the positional accuracy of corresponding image points of PCAM stereo images within 1 pixel. So the measurement methods and parameter accuracy studied in this paper meet the needs of engineering and scientific applications. Keywords: Chang'E-5 Mission; Panoramic Camera; Installation Parameters; Total Station; Coordinate Conversion

  5. Novel MRI approaches for assessing cerebral hemodynamics in ischemic cerebrovascular disease.

    PubMed

    Donahue, Manus J; Strother, Megan K; Hendrikse, Jeroen

    2012-03-01

    Changes in cerebral hemodynamics underlie a broad spectrum of ischemic cerebrovascular disorders. An ability to accurately and quantitatively measure hemodynamic (cerebral blood flow and cerebral blood volume) and related metabolic (cerebral metabolic rate of oxygen) parameters is important for understanding healthy brain function and comparative dysfunction in ischemia. Although positron emission tomography, single-photon emission tomography, and gadolinium-MRI approaches are common, more recently MRI approaches that do not require exogenous contrast have been introduced with variable sensitivity for hemodynamic parameters. The ability to obtain hemodynamic measurements with these new approaches is particularly appealing in clinical and research scenarios in which follow-up and longitudinal studies are necessary. The purpose of this review is to outline current state-of-the-art MRI methods for measuring cerebral blood flow, cerebral blood volume, and cerebral metabolic rate of oxygen and provide practical tips to avoid imaging pitfalls. MRI studies of cerebrovascular disease performed without exogenous contrast are synopsized in the context of clinical relevance and methodological strengths and limitations.

  6. Training-induced changes in clotting parameters of athletic horses

    PubMed Central

    Bazzano, Marilena; Giannetto, Claudia; Marafioti, Simona; Fazio, Francesco

    2014-01-01

    The purpose of this study was to investigate the effects of training on prothrombin time, activated partial thromboplastin time, and fibrinogen (Fb) concentrations in horses to assess potential adaptive response to training. Fifteen clinically healthy horses were enrolled in the present study and equally divided into three groups. Group A completed an intense training program, group B participated in a light training program, and group C included sedentary horses. After 5 weeks, group B was subjected to the same training program completed by group A and renamed group B1. Blood samples were collected by jugular venipuncture from each animal at rest and analyzed within 2 h after sampling. A two-way ANOVA for repeated measures showed a significant effect of training (p < 0.05) on Fb concentrations in group B1 alone during the first week after changing the training program. Our findings demonstrated that Fb is a parameter susceptible to training. Fb plasma levels increase with a more intense training program. However, Fb plasma levels decreased after the first week and returned to basel levels, suggesting that the horses had adapted to the new training program. PMID:24136203

  7. Hemodynamic parameters that may predict false-lumen growth in type-B aortic dissection after endovascular repair: A preliminary study on long-term multiple follow-ups.

    PubMed

    Xu, Huanming; Li, Zhenfeng; Dong, Huiwu; Zhang, Yilun; Wei, Jianyong; Watton, Paul N; Guo, Wei; Chen, Duanduan; Xiong, Jiang

    2017-09-07

    Thoracic endovascular aortic repair (TEVAR) is commonly applied in type-B aortic dissection. For patients with dissection affects descending aorta and extends downward to involve abdominal aorta and possibly iliac arteries, false lumen (FL) expansion might occur post-TEVAR. Predictions of dissection development may assist in medical decision on re-intervention or surgery. In this study, two patients are selected with similar morphological features at initial presentation but with different long-term FL development post-TEVAR (stable and enlarged FL). Patient-specific models are established for each of the follow-ups. Flow boundaries and computational validations are obtained from Doppler ultrasound velocimetry. By analyzing the hemodynamic parameters, the false-to-true luminal pressure difference (PDiff) and particle relative residence time (RRT) are found related to FL remodeling. It is found that (i) the position of the first FL flow entry is the watershed of negative-and-positive PDiff and, in long-term follow-ups, and the position of largest PDiff is consistent with that of the greatest increase of FL width; (ii) high RRT occurs at the FL proximal tip and similar magnitude of RRT is found in both stable and enlarged cases; (iii) comparing to the RRT at 7days post-TEVAR, an increase of RRT afterwards in short-term is found in the stable case while a slight decrease of this parameter is found in the enlarged case, indicating that the variation of RRT in short-term post-TEVAR might be potential to predict long-term FL remodeling. Copyright © 2017 IPEM. Published by Elsevier Ltd. All rights reserved.

  8. [Hemodynamic evaluation of the patient with microvarices].

    PubMed

    Alvarez Sánchez, J A; Vega Gómez, M E; Rodríguez Lacaba, B; Martínez Griñán, M A

    1992-01-01

    The present study included 21 lower limbs with micro varicosities, 56 lower limbs with retrograde flow-varicosities (positive Rivlin) and 35 health lower limbs. Technics used for diagnosis were: Doppler ultrasonography and strain gauge plethysmography. We found a higher incidence of valvular failure on the varicose patients with retrograde flow (showing changes on their viscoelastic features of their venous walls). On the contrary, patient with microvaricosities showed an hemodynamics similar to the healty patient: we did not found any difference on the variables analyzed between the two groups. We conclude that the presence of microvaricosities has no influence on the analyzed hemodynamic parametres.

  9. Physiological responses to environmental factors related to space flight. [hemodynamic and metabolic responses to weightlessness

    NASA Technical Reports Server (NTRS)

    Pace, N.

    1973-01-01

    Physiological base line data are established, and physiological procedures and instrumentation necessary for the automatic measurement of hemodynamic and metabolic parameters during prolonged periods of weightlessness are developed.

  10. Evidence that meal fat content does not impact hemodynamic reactivity to or recovery from repeated mental stress tasks.

    PubMed

    Poitras, Veronica J; Slattery, David J; Gurd, Brendon J; Pyke, Kyra E

    2014-11-01

    The magnitude (reactivity) and duration (recovery) of hemodynamic stress responses are predictive of cardiovascular risk, and fat intake has been shown to enhance hemodynamic reactivity to psychological stress tasks. The objective of this study was to determine the impact of a high-fat meal (HFM) on the magnitude and stability of hemodynamic stress reactivity and recovery. This was assessed by: (i) the peak changes from baseline to during stress for heart rate (HR); mean, systolic, and diastolic blood pressure; cardiac output; and total peripheral resistance; and (ii) the residual arousal in hemodynamic parameters at 2 points post-stress ("early" and "late" recovery). On different days, 10 healthy males (aged 23.2 ± 3.3 years) consumed either a HFM (54 g fat) or low-fat meal (LFM; 0 g fat) (∼1000 calories each), followed by 4 hourly 10-min stress tasks (mental arithmetic and speech tasks). Pre-stress (baseline) parameters did not differ between HFM and LFM conditions (all P > 0.05). Plasma triglycerides were greater following the HFM versus the LFM (P = 0.023). No reactivity or recovery parameters differed between meals (all P > 0.05). Stress reactivity and recovery parameters were stable over the 4 stress tasks (main effects of time, all P > 0.05), with the exception of HR (P < 0.05). Contrary to previous reports, meal fat content did not impact hemodynamic reactivity to laboratory stressors. These data also provide the first evidence that meal fat content does not impact hemodynamic recovery from repeated mental stress tasks.

  11. Perfusion index versus non-invasive hemodynamic parameters during insertion of i-gel, classic laryngeal mask airway and endotracheal tube.

    PubMed

    Atef, Hosam M; Fattah, Salah Abd; Gaffer, Mohammed Emad Abd; Al Rahman, Ahamed Abd

    2013-03-01

    Perfusion index (PI) is a non-invasive numerical value of peripheral perfusion obtained from a pulse oximeter. In this study, we evaluated the efficacy of PI for detecting haemodynamic stress responses to insertion of i-gel, laryngeal mask airway (LMA) and endotracheal tube and compare, its reliability with the conventional haemodynamic criteria in adults during general anaesthesia. Sixty patients scheduled for elective general surgery under general anaesthesia were randomised to three groups. (i-gel, LMA and ET groups (n=20/group). Heart rate (HR) (positive if ≥10 bpm), systolic blood pressure (SBP), diastolic blood pressure (DBP) (positive if ≥15 mm Hg) and PI (positive if ≤10%) were monitored for 5 min after insertion. SBP, DBP, HR and PI were measured before induction of anaesthesia and before and after insertion of the airway device. Insertion of airway devices produced significant increases in HR, SBP and DBP in LMA and ET groups. Moreover, PI was decreased significantly by 40%, 100% and 100% in the three groups. Using the PI criterion, the sensitivity was 100% (CI 82.4-100.0%). Regarding the SBP and DBP criterions, the sensitivity was 44.4% (CI 24.6-66.3%), 55.6% (CI 33.7-75.4%) respectively. Also, significant change in the mean PI over time (from pre-insertion value to the 1(st) min, 3(rd) min, until the 4(th) min after insertion without regard the device type), (P<0.001). PI is a reliable and easier alternative to conventional haemodynamic criteria for detection of stress response to insertion of i-gel, LMA and ET during propofol fentanyl isoflurane anaesthesia in adult patients.

  12. [Hemodynamic effects of spinal anaesthesia during caesarian section in pregnant women with hypertensive disorders].

    PubMed

    Kinzhalova, S V; Makarov, R A; Davydova, N S

    2014-01-01

    To make the comparative analysis of the changes of main parameters of haemodynamic during caesarean section with spinal anaesthesia (SA) in patients with uncomplicated pregnancy and pregnancy with hypertensive disorders. The study included 103 pregnant women undergoing caesarean section under SA. The comparative analysis of the main haemodynamic parameters was performed in patients into three groups: an uncomplicated pregnancy (n = 35); pregnancy with chronic hypertension (n = 33) and pregnancy complicated by severe preeclampsia (n = 35). Heart rate (HR), mean blood pressure (BP), cardiac index (CI) and systemic vascular resistance (SVR) were measured by noninvasive bioimpedans technology. Data were recorded at 5 stages of the study. The data of study demonstrated that haemodynamic stability better if SA is used during caesarean section in women with normal pregnancy. In the group of pregnant women with severe preeclampsia observed the most significant hemodynamic changes: BP and SVR decreased significantly greater at all stages of the operation, whereas the increase SI on the 3rd stage was higher in comparison with the control group. There were significant differences changes in the main hemodynamic parameters between groups at all stages of the study. Results of this survey suggest that hemodynamic response to anaesthesia depends on the initial state of the circulatory system.

  13. Hemodynamic effect of iloprost inhalation and oral sildenafil during acute vasoreactivity test in pulmonary arterial hypertension.

    PubMed

    Sompradeekul, Suree; Wattanasiriphakdee, Siriphan

    2015-02-01

    The vasoreactivity test is usually performed to identify pulmonary arterial hypertension (PAH) patients who may benefit from long-term calcium channel blocker (CCB). The first and most commonly used agent is intravenous epoprostenol. A few other agents such as intravenous adenosine and inhaled nitric oxide are also used. In Thailand, epoprostenol is not available and the others are costly. Therefore, inhaled iloprost or oral sildenafil may be alternatives to test vasoreactivity. To evaluate the hemodynamic effect and response rate of inhaled iloprost and oral sildenafil during acute vasoreactivity test in PAH patients. In this retrospective descriptive study, the authors recruited patients with idiopathic PAH (IPAH) or PAHassociated with connective tissue disease (PAH-CNT) seen at the Medicine department Siriraj Hospital between January 2005 and December 2011 for whom acute vasoreactivity test was indicated. All patients used 20 microgram of inhaled iloprost via Delphinus® nebulizer for the test. Hemodynamic parameters were recorded before and after iloprost administration. Eight of those patients subsequently had a repeated test using 100 mg of oral sildenafil. Fifteen patients had acute vasoreactivity testing. Eleven patients were IPAH and four were PAH-CNT Using ESC/ERS guidelines criteria for responsiveness to vasoreactivity test, the response rate was 13% (2 out of 15 patients) using inhaled iloprost. Hemodynamic change was seen as early as five minutes after the inhalation and the effect lasted up to 35 minutes. The response rate was 25% (2 out of 8 patients) using oral sildenafil. Hemodynamic change was seen as early as 30 minutes after sildenafil ingestion and lasted up to 480 minutes. Inhaled iloprost can be used for acute vasoreactivity test in Thailand. The hemodynamic parameters should be recorded immediately after iloprost inhalation. Oral sildenafil, however, is not a suitable agent for acute vasoreactivity test due to its extended effect.

  14. [Changes of the hemodynamics and extravascular lung water after different-volume fluid resuscitation in a piglet model of endotoxic shock].

    PubMed

    Wu, Fang; Lu, Guo-ping; Lu, Zhu-jin; Wu, Jing-lei; Li, Zhen; Hong, Jian-guo; Zhang, Ling-en

    2013-09-01

    Practice recommendations have evolved, and consensus now exists among leading organizations such as the American College of Critical Care Medicine (ACCM) and Surviving Sepsis Campaign that fluid infusion is best initiated with boluses of 20 ml/kg, commonly requires 40-60 ml/kg but can be as much as 200 ml/kg if the liver is not enlarged and/or rales are not heard. The present study aimed to investigate and compare the changes of the hemodynamics and extravascular lung water after higher volume fluid resuscitation in a piglet model of endotoxic shock. Twenty piglets were used for establishing animal models of endotoxic shock by intravenous infusing lipopolysaccharide (LPS). The experimental animals were divided into three groups according to the volume infused during the resuscitation. The three groups received different volume of saline in less than an hour after endotoxic shock. By the PiCCO plus system, we investigated the changes of hemodynamics and extravascular lung water. After fluid resuscitation, global end diastolic volume inder, (GEDI) and intrathoracic blood volume index, (ITBI) markedly increased in the group of 80 ml/kg and 120 ml/kg, but there was no change in the group of 40 ml/kg. GEDI: Fifteen min after fluid resuscitation R1 was (261 ± 64) ml/m(2), R2 (457 ± 124) ml/m(2), R3 (413 ± 148) ml/m(2), 4 h R1 (251 ± 68) ml/m(2), R2 (422 ± 70) ml/m(2), R3 (470 ± 160) ml/m(2); ITBI: Fifteen min after fluid resuscitation R1 was (335 ± 69) ml/m(2), R2 (550 ± 179) ml/m(2), R3 (520 ± 183) ml/m(2), 4 h R1 (314 ± 84) ml/m(2), R2 (534 ± 96) ml/m(2), R3 (594 ± 200) ml/m(2) (R1 vs. R2 vs. R3, F = 26.373, P < 0.05; R1 vs. R2, R1 vs. R3, P < 0.05; R2 vs. R3, P > 0.05). CI of all three groups significantly decreased when the models were established. After fluid resuscitation, the base level was maintained in the group of 80 ml/kg and 120 ml/kg, but it was under the basic level in the group of 40 ml/kg.Fifteen min after fluid resuscitation R1 was (4.5 ± 0

  15. Cerebrovascular hemodynamics during pranayama techniques

    PubMed Central

    Nivethitha, L.; Mooventhan, A.; Manjunath, N. K.; Bathala, Lokesh; Sharma, Vijay K.

    2017-01-01

    Background: Pranayama techniques are known to produce variable physiological effects on the body. We evaluated the effect of the two commonly practiced Pranayama techniques on cerebral hemodynamics. Materials and Methods: Fifteen healthy male volunteers, trained in Yoga and Pranayama, were included in the study. Mean age was 24 years (range 22–32 years). Study participants performed 2 Pranayamas in 2 different orders. Order 1 (n = 7) performed Bhastrika (bellows breaths) followed by Kumbhaka (breath retention) while order 2 (n = 8) performed Kumbhaka followed by Bhastrika. Both breathing techniques were performed for 1 min each. Continuous transcranial Doppler (TCD) monitoring was performed during the breathing techniques. TCD parameters that were recorded included peak systolic velocity (PSV), end-diastolic velocity (EDV), mean flow velocity (MFV), and pulsatility index (PI) of the right middle cerebral artery at baseline, 15, 30, 45, and 60 s. Results: Significant reductions in EDV (3.67 ± 6.48; P < 0.001) and MFV (22.00 ± 7.30; P < 0.001) with a significant increase in PI (2.43 ± 0.76; P < 0.001) were observed during Bhastrika. On the contrary, a significant increase in PSV (65.27 ± 13.75; P < 0.001), EDV (28.67 ± 12.03; P < 0.001), and MFV (43.67 ± 12.85; P < 0.001) with a significant reduction in PI (0.89 ± 0.28; P < 0.01) was observed only during Kumbhaka. Conclusion: Bhastrika and Kumbhaka practices of Pranayama produce considerable and opposing effects on cerebral hemodynamic parameters. Our findings may play a potential role in designing the Pranayama techniques according to patients’ requirements. PMID:28149083

  16. Ocular hemodynamics during isometric exercise.

    PubMed

    Kiss, B; Dallinger, S; Polak, K; Findl, O; Eichler, H G; Schmetterer, L

    2001-01-01

    The autoregulatory capacity of the human retina is well documented, but the pressure-flow relationship of the human choroid is still a matter of controversy. Recent data, using laser Doppler flowmetry to measure choroidal blood flow, indicate that the choroid has some autoregulatory potential, whereas most data using other techniques for the assessment of choroidal hemodynamics indicate that the choroidal pressure-flow curve is linear. We used a new laser interferometric technique to characterize choroidal blood flow during isometric exercise. Twenty healthy subjects performed squatting for 6 min during normocapnia and during inhalation of 5% CO2 and 95% air. Ocular fundus pulsation amplitude, flow velocities in the ophthalmic artery, intraocular pressure, and systemic hemodynamics were measured in 2-min intervals. To gain information on choroidal blood flow fundus pulsation amplitude was corrected for changes in flow pulsatility using data from the ophthalmic artery and for changes in pulse rate. Ocular perfusion pressure was calculated from mean arterial pressure and intraocular pressure. The ocular pressure-flow relationship was calculated by sorting data according to ascending ocular perfusion pressure values. In a pilot study in 6 healthy subjects comparable ocular pressure flow relationships were obtained when choroidal blood flow was assessed with the method described above and with laser Doppler flowmetry. In the main study isometric exercise caused a significant increase in mean arterial pressure (56%, P < 0.001), pulse rate (84%, P < 0.001), and intraocular pressure (37%, P 0.004), but decreased fundus pulsation amplitude (-36%, P < 0.001). Significant deviations from baseline choroidal blood flow were observed only at ocular perfusion pressures >69% during normocapnia and 70% during hypercapnia. Our data indicate that during isometric exercise the choroid has a high capacity to keep blood flow constant despite changes in perfusion pressure and that this

  17. Basic Perforator Flap Hemodynamic Mathematical Model.

    PubMed

    Tao, Youlun; Ding, Maochao; Wang, Aiguo; Zhuang, Yuehong; Chang, Shi-Min; Mei, Jin; Tang, Maolin; Hallock, Geoffrey G

    2016-05-01

    A mathematical model to help explain the hemodynamic characteristics of perforator flaps based on blood flow resistance systems within the flap will serve as a theoretical guide for the future study and clinical applications of these flaps. There are 3 major blood flow resistance network systems of a perforator flap. These were defined as the blood flow resistance of an anastomosis between artery and artery of adjacent perforasomes, between artery and vein within a perforasome, and then between vein and vein corresponding to the outflow of that perforasome. From this, a calculation could be made of the number of such blood flow resistance network systems that must be crossed for all perforasomes within a perforator flap to predict whether that arrangement would be viable. The summation of blood flow resistance networks from each perforasome in a given perforator flap could predict which portions would likely survive. This mathematical model shows how this is directly dependent on the location of the vascular pedicle to the flap and whether supercharging or superdrainage maneuvers have been added. These configurations will give an estimate of the hemodynamic characteristics for the given flap design. This basic mathematical model can (1) conveniently determine the degree of difficulty for each perforasome within a perforator flap to survive; (2) semiquantitatively allow the calculation of basic hemodynamic parameters; and (3) allow the assessment of the pros and cons expected for each pattern of perforasomes encountered clinically based on predictable hemodynamic observations.

  18. Lack of Association Between Limb Hemodynamics and Response to Infrapopliteal Endovascular Therapy in Patients With Critical Limb Ischemia.

    PubMed

    Mustapha, J A; Diaz-Sandoval, Larry J; Adams, George; Jaff, Michael R; Beasley, Robert; McGoff, Theresa; Finton, Sara; Miller, Larry E; Ansari, Mohammad; Saab, Fadi

    2017-05-01

    Non-invasive limb hemodynamics may aid in diagnosis of critical limb ischemia (CLI), although the relationship with disease severity and response to endovascular therapy is unclear. This prospective, single-center study enrolled 100 CLI patients (Rutherford class 4-6) who underwent infrapopliteal endovascular revascularization (175 lesions) in the Peripheral RegIstry of Endovascular Clinical OutcoMEs (PRIME) registry. Hemodynamic measures included ankle-brachial index (ABI), toe-brachial index (TBI), and toe pressure (TP). Procedure success following revascularization was defined as stenosis ≤30%. Hemodynamic success was defined as an increase >0.15 in ABI or TBI relative to baseline. Freedom from amputation was defined as no major or minor amputation during follow-up. Clinical success was defined as a decrease of at least one Rutherford class during follow-up. Treatment success was defined as procedure success, freedom from amputation, and clinical improvement. Median baseline hemodynamic values were 0.90 for ABI, 0.39 for TBI, and 54 mm Hg for TP. Twenty-nine patients (29%) did not meet the common hemodynamic diagnostic criterion for eligibility in CLI trials (ABI ≤0.5, TBI ≤0.5, or TP <50 mm Hg). Main outcomes included 96% procedure success, 95% freedom from amputation, 64% clinical success, and 62% treatment success. There was no relationship between baseline (or with the pretreatment to posttreatment change) limb hemodynamic values and the response to infrapopliteal endovascular therapy. Non-invasive hemodynamic studies may have limited clinical usefulness in patients with CLI. The usefulness of these parameters to confirm eligibility and to assess response to therapy in interventional CLI clinical trials should be re-evaluated.

  19. [Hemodynamic Status of Prepubertal and Pubertal Hockey Players].

    PubMed

    Shayhelislamova, M V; Sitdikov, F G; Zefirov, T L; Dikopolskaya, N B

    2015-01-01

    The hemodynamic status of 11-15-year-old hockey players depending on their age and puberty stage were studied and compared with hemodynamic parameters of the control group. It was found that regular muscle training has a dominant effect on the functional state of cardiovascular system (CVS) in prepuberty and puberty. It was proved that in hockey players a decrease in the heart rate (H R) and an increase in the stroke volume (SV) result in a significant increase in systolic blood pressure (SBP) at the age of 11-14 years and a progressive increase in total peripheral vascular resistance (PVR), in contrast to significantly lower values in the control group. The urgent adaptation of CVS to graduated physical activities at the age of 11-13 years leads to an enhancement of vascular spasmodic reactions while SV remains constant. It was found that in adolescent hockey players have consistently high SV and SBP; at the same time, maximal values of HR, cardiac output (CO) and diastolic blood pressure (DBP) were observed at the stages I and II of the puberty period; then, at the stage III, these parameters decrease. I n the control group, hymodinamic status changed in an opposite way. This may be an evidence of the stress effect of physical activities which results in the adaptive reactions of CVS rather than reactions typical of the puberty period.

  20. Transitional Hemodynamics in Preterm Neonates: Clinical Relevance.

    PubMed

    Wu, Tai-Wei; Azhibekov, Timur; Seri, Istvan

    2016-02-01

    Each newborn enters this world facing tremendous respiratory, hemodynamic and neuroendocrine challenges while going through drastic physiological changes during the process of adaption from fetal to postnatal life. Even though the vast majority of term infants transition smoothly without apparent consequences, this task becomes increasingly arduous for the extremely preterm infant. This article reviews the physiology and pathophysiology of cardiovascular adaptation of the very preterm neonate. In particular it describes the physiology of fetal circulation, summarizes the hemodynamic changes occurring during preterm births and discusses the impact of the most frequently seen clinical scenarios that place additional burden on the premature infant during immediate transition. Finally an emphasis is placed on discussing common clinical dilemmas and practical aspects of developmental hemodynamics such as neonatal hypotension and patent ductus arteriosus; clinical presentations the neonatologist encounters on a daily basis. The review provides a physiology-based view on the hemodynamics of the immediate postnatal transitional period. Copyright © 2016. Published by Elsevier B.V.

  1. Acute effects of ferumoxytol on regulation of renal hemodynamics and oxygenation

    PubMed Central

    Cantow, Kathleen; Pohlmann, Andreas; Flemming, Bert; Ferrara, Fabienne; Waiczies, Sonia; Grosenick, Dirk; Niendorf, Thoralf; Seeliger, Erdmann

    2016-01-01

    The superparamagnetic iron oxide nanoparticle ferumoxytol is increasingly used as intravascular contrast agent in magnetic resonance imaging (MRI). This study details the impact of ferumoxytol on regulation of renal hemodynamics and oxygenation. In 10 anesthetized rats, a single intravenous injection of isotonic saline (used as volume control) was followed by three consecutive injections of ferumoxytol to achieve cumulative doses of 6, 10, and 41 mg Fe/kg body mass. Arterial blood pressure, renal blood flow, renal cortical and medullary perfusion and oxygen tension were continuously measured. Regulation of renal hemodynamics and oxygenation was characterized by dedicated interventions: brief periods of suprarenal aortic occlusion, hypoxia, and hyperoxia. None of the three doses of ferumoxytol resulted in significant changes in any of the measured parameters as compared to saline. Ferumoxytol did not significantly alter regulation of renal hemodynamics and oxygenation as studied by aortic occlusion and hypoxia. The only significant effect of ferumoxytol at the highest dose was a blunting of the hyperoxia-induced increase in arterial pressure. Taken together, ferumoxytol has only marginal effects on the regulation of renal hemodynamics and oxygenation. This makes ferumoxytol a prime candidate as contrast agent for renal MRI including the assessment of renal blood volume fraction. PMID:27436132

  2. Combining numerical and clinical methods to assess aortic valve hemodynamics during exercise.

    PubMed

    Bahraseman, Hg; Hassani, K; Khosravi, A; Navidbakhsh, M; Espino, Dm; Fatouraee, N; Kazemi-Saleh, D

    2014-07-01

    Computational simulations have the potential to aid understanding of cardiovascular hemodynamics under physiological conditions, including exercise. Therefore, blood hemodynamic parameters during different heart rates, rest and exercise have been investigated, using a numerical method. A model was developed for a healthy subject. Using geometrical data acquired by echo-Doppler, a two-dimensional model of the chamber of aortic sinus valsalva and aortic root was created. Systolic ventricular and aortic pressures were applied as boundary conditions computationally. These pressures were the initial physical conditions applied to the model to predict valve deformation and changes in hemodynamics. They were the clinically measured brachial pressures plus differences between brachial, central and left ventricular pressures. Echocardiographic imaging was also used to acquire different ejection times, necessary for pressure waveform equations of blood flow during exercise. A fluid-structure interaction simulation was performed, using an arbitrary Lagrangian-Eulerian mesh. During exercise, peak vorticity increased by 14.8%, peak shear rate by 15.8%, peak cell Reynolds number by 20%, peak leaflet tip velocity increased by 47% and the blood velocity increased by 3% through the leaflets, whereas full opening time decreased by 11%. Our results show that numerical methods can be combined with clinical measurements to provide good estimates of patient-specific hemodynamics at different heart rates.

  3. Maternal hemodynamic influence on uteroplacental oxygen distribution during cesarean section.

    PubMed

    Koković, J Tomanović; Radunovic, N; Filimonović, D; Nejković, L; Arsenijević, L; Mirković, L J; Koković, V

    2015-01-01

    This study investigated maternal hemodynamic influence on uteroplacental oxygen distribution and neonatal outcome during cesarean section (CS). CS was performed on 80 parturients using two anaesthetic techniques: spinal anaesthesia (SA) and general balanced anaesthesia (GBA). Indications for CS were exclusively obstetric related. Monitored maternal parameters were: ECG, heart rate (HR), non-invasive blood pressure (NIBP), saturation (SaO2). Gas parameters in umbilical artery, vein, and neonatal capillary blood were sampled. Vitality was assessed by the Apgar scoring, first breath-taking time and the first breastfeeding attempt. Hypotension was the most common finding after SA induction. GBA group presented changes such as QT inversion (12.5%), tachycardia (55%), and bradycardia (2.5%). SA group experienced higher rates of sinus tachycardia (45%) and ventricular dysrhythmias (2.5%). Neonatal oxygenation was significantly higher in SA group. Higher quality of early neonatal adaptation in the SA group confirms it as the technique with the least neonatal risk during CS.

  4. Hemodynamic and neuropathological analysis in rats with aluminum trichloride-induced Alzheimer's disease.

    PubMed

    Chen, Szu-Ming; Fan, Chi-Chen; Chiue, Ming-Shiuan; Chou, Chi; Chen, Jyh-Horng; Hseu, Ruey-Shyang

    2013-01-01

    Hemodynamic normality is crucial to maintaining the integrity of cerebral vessels and, therefore, preserving the cognitive functions of Alzheimer's disease patients. This study investigates the implications of the hemodynamic changes and the neuropathological diversifications of AlCl3-induced AD. The experimental animals were 8- to 12-wk-old male Wistar rats. The rats were randomly divided into 2 groups: a control group and a (+)control group. Food intake, water intake, and weight changes were recorded daily for 22 wk. Synchronously, the regional cerebral blood flow (rCBF) of the rats with AlCl3-induced AD were measured using magnetic resonance imaging (MRI). The hemorheological parameters were analyzed using a computerized auto-rotational rheometer. The brain tissue of the subjects was analyzed using immunohistological chemical (IHC) staining to determine the beta-amyloid (Aβ) levels. The results of hemodynamic analysis revealed that the whole blood viscosity (WBV), fibrinogen, plasma viscosity and RBC aggregation index (RAI) in (+)control were significantly higher than that of control group, while erythrocyte electrophoresis (EI) of whole blood in (+)control were significantly lower than that of control group. The results of acetylcholinesterase-RBC (AChE-RBC)in the (+)control group was significantly higher than that of the control group. The results also show that the reduction of rCBF in rats with AlCl3-induced AD was approximately 50% to 60% that of normal rats. IHC stain results show that significantly more Aβ plaques accumulated in the hippocampus and cortex of the (+)control than in the control group. The results accentuate the importance of hemorheology and reinforce the specific association between hemodynamic and neuropathological changes in rats with AlCl3-induced AD. Hemorheological parameters, such as WBV and fibrinogen, and AChE-RBC were ultimately proven to be useful biomarkers of the severity and progression of AD patients. In addition, the

  5. Hemodynamic Improvement in Cardiac Resynchronization Does Not Require Improvement in Left Ventricular Rotation Mechanics

    PubMed Central

    Ashikaga, Hiroshi; Leclercq, Christophe; Wang, Jiangxia; Kass, David A.; McVeigh, Elliot R.

    2010-01-01

    Background Earlier studies have yielded conflicting evidence on whether or not cardiac resynchronization therapy (CRT) improves left ventricular (LV) rotation mechanics. Methods and Results In dogs with left bundle branch block and pacing-induced heart failure (n=7), we studied the effects of CRT on LV rotation mechanics in vivo by 3-dimensional tagged magnetic resonance imaging with a temporal resolution of 14 ms. CRT significantly improved hemodynamic parameters but did not significantly change the LV rotation or rotation rate. LV torsion, defined as LV rotation of each slice with respect to that of the most basal slice, was not significantly changed by CRT. CRT did not significantly change the LV torsion rate. There was no significant circumferential regional heterogeneity (anterior, lateral, inferior, and septal) in LV rotation mechanics in either left bundle branch block with pacing-induced heart failure or CRT, but there was significant apex-to-base regional heterogeneity. Conclusions CRT acutely improves hemodynamic parameters without improving LV rotation mechanics. There is no significant circumferential regional heterogeneity of LV rotation mechanics in the mechanically dyssynchronous heart. These results suggest that LV rotation mechanics is an index of global LV function, which requires coordination of all regions of the left ventricle, and improvement in LV rotation mechanics appears to be a specific but insensitive index of acute hemodynamic response to CRT. PMID:20478988

  6. Cerebral hemodynamics and cognitive impairment

    PubMed Central

    Festa, J.R.; Cheung, Y.K.; Chen, R.; Pavol, M.A.; Derdeyn, C.P.; Clarke, W.R.; Videen, T.O.; Grubb, R.L.; Adams, H.P.; Powers, W.J.; Lazar, R.M.

    2012-01-01

    Objective: To determine whether unihemispheral hemodynamic failure is independently associated with cognitive impairment among participants in the National Institute of Neurological Disorders and Stroke–sponsored, multicenter, randomized clinical trial, Randomized Evaluation of Carotid Occlusion and Neurocognition (RECON). Methods: Forty-three patients were randomized into RECON after recent symptomatic carotid artery occlusion and asymmetrically increased oxygen extraction fraction (OEF) by PET (OEF ratio >1.13), indicating stage II hemodynamic failure on the side of occlusion. The PET-positive patients were compared with 28 RECON-enrolled patients who met all clinical and radiographic inclusion/exclusion criteria but had no OEF asymmetry. A multivariable regression compared patients with PET OEF >1.13 or ≤1.13, stratifying by TIA vs stroke as the qualifying event. The dependent variable was a composite neurocognitive score derived from averaging age-normalized z scores on a test battery that included global and internal carotid artery (ICA) side-relevant hemisphere-specific tests. Results: There were no differences in demographic, clinical, or radiologic characteristics between the PET-positive and PET-negative patients except for PET OEF asymmetry. The unadjusted average neurocognitive z score was −1.45 for the PET-positive and −1.25 for the PET-negative patients, indicating cognitive impairment in both groups but no difference between them (p = 0.641). After adjustment for age, education, side of occlusion, depression, and previous stroke, there was a significant difference between PET-positive and PET-negative patients among those with TIA as a qualifying event (average z score = −1.41 vs −0.76, p = 0.040). Older age and right ICA side were also significant in this model. Conclusion: Hemodynamic failure is independently associated with cognitive impairment in patients with carotid occlusion. This finding establishes the physiologic parameter upon

  7. Sample Size Planning for Longitudinal Models: Accuracy in Parameter Estimation for Polynomial Change Parameters

    ERIC Educational Resources Information Center

    Kelley, Ken; Rausch, Joseph R.

    2011-01-01

    Longitudinal studies are necessary to examine individual change over time, with group status often being an important variable in explaining some individual differences in change. Although sample size planning for longitudinal studies has focused on statistical power, recent calls for effect sizes and their corresponding confidence intervals…

  8. Parameters of Institutional Change: Chicano Experience in Education.

    ERIC Educational Resources Information Center

    Santana, Ray; And Others

    During the 1960's, the Chicano movement directed considerable attention, energy, and resources toward educational change. The predominant mood was optimism and anticipation of major institutional change; the predominant tactic used was militant confrontation. Countless confrontations occurred and numerous plans and strategies for educational…

  9. Hemodynamic aspects of normal human feto-placental (umbilical) circulation.

    PubMed

    Acharya, Ganesh; Sonesson, Sven-Erik; Flo, Kari; Räsänen, Juha; Odibo, Anthony

    2016-06-01

    Understanding the changes in normal circulatory dynamics that occur during the course of pregnancy is essential for improving our knowledge of pathophysiological mechanisms associated with feto-placental diseases. The umbilical circulation is the lifeline of the fetus, and it is accessible for noninvasive assessment. However, not all hemodynamic parameters can be reliably measured in utero using currently available technology. Experimental animal studies have been crucial in validating major concepts related to feto-placental circulatory physiology, but caution is required in directly translating the findings of such studies into humans due to species differences. Furthermore, it is important to establish normal reference ranges and take into account gestational age associated changes while interpreting the results of clinical investigation. Therefore, it is necessary to critically evaluate, synthesize and summarize the knowledge available from the studies performed on human pregnancies to be able to appropriately apply them in clinical practice. This narrative review is an attempt to present contemporary concepts on hemodynamics of feto-placental circulation based on human studies. © 2016 Nordic Federation of Societies of Obstetrics and Gynecology.

  10. The effect of trabeculectomy on ocular hemodynamics.

    PubMed Central

    Cantor, L B

    2001-01-01

    PURPOSE: To evaluate the effects of chronic reduction of intraocular pressure (IOP) on ocular hemodynamics. METHODS: Multisite, prospective evaluation of patients requiring trabeculectomy for treatment of glaucoma. Patients were recruited from the glaucoma service of 2 university hospitals. Patients were evaluated prior to surgery and at 3, 6, and 12 months after trabeculectomy. Color Doppler imaging was used to measure blood flow in the ophthalmic artery, central retinal artery, and short posterior ciliary arteries. Heidelberg retinal flowmetry was used to evaluate perfusion in the peripapillary and optic disc capillary beds. IOP was measured at baseline and at each study visit. RESULTS: There were highly significant reductions in IOP from presurgical baseline measures. At 3 months, mean IOP reduction was 17.1 mm Hg (62.3%; P < .001). At the 6- and 12-month evaluations, the mean IOP reductions were 15.7 mm Hg (57.3%) and 15.5 mm Hg (56.5%), respectively, P < .001. Despite the significant reduction in IOP, there were no significant differences in any ocular blood flow parameters before and after trabeculectomy. CONCLUSIONS: The findings of this study suggest that chronic reduction of IOP does not alter ocular blood flow and that IOP may be an independent risk factor for progression of glaucoma. These findings also suggest that the eye has the ability to autoregulate to chronically increased IOP over time and that additional studies evaluating the long-term effects of IOP changes are needed to further define this relationship. PMID:11797313

  11. Statins and cerebral hemodynamics

    PubMed Central

    Giannopoulos, Sotirios; Katsanos, Aristeidis H; Tsivgoulis, Georgios; Marshall, Randolph S

    2012-01-01

    HMG-CoA reductase inhibitors (statins) are associated with improved stroke outcome. This observation has been attributed in part to the palliative effect of statins on cerebral hemodynamics and cerebral autoregulation (CA), which are mediated mainly through the upregulation of endothelium nitric oxide synthase (eNOS). Several animal studies indicate that statin pretreatment enhances cerebral blood flow after ischemic stroke, although this finding is not further supported in clinical settings. Cerebral vasomotor reactivity, however, is significantly improved after long-term statin administration in most patients with severe small vessel disease, aneurysmal subarachnoid hemorrhage, or impaired baseline CA. PMID:22929438

  12. Renal hemodynamic effects of relaxin in humans.

    PubMed

    Smith, Marie; Davison, John; Conrad, Kirk; Danielson, Lee

    2005-05-01

    Rat studies have convincingly demonstrated the essential role of the ovarian hormone relaxin in mediating gestational renal hemodynamic and osmoregulatory changes in that species. We describe a model in nonpregnant volunteers using exogenous hCG to stimulate the production and release of ovarian relaxin in order to assess renal hemodynamic responses. Women (n = 10) were serially studied +/- hCG stimulation during menstrual cycles with measurement of inulin, PAH, and neutral dextran clearances (to determine glomerular filtration rate [GFR], renal plasma flow [RPF], and glomerular porosity, respectively). Controls were women without ovarian function (n = 6) and men (n = 10). GFR and RPF were increased in the luteal phase compared to the follicular phase (15.3% increase in GFR, P < 0.005; 17.8% increase in RPF, P < 0.05). In controls, GFR and RPF were not significantly different between study occasions. Although exogenous hCG did not stimulate relaxin secretion in women without ovarian function or in men, it did so in normal women, but not into the pregnancy range. In no group were renal hemodynamics augmented by administered hCG. In naturally occurring cycles, increased serum relaxin is associated with augmented renal hemodynamics. As luteal stimulation with hCG failed to yield pregnancy relaxin levels, the use of exogenous relaxin for human administration is needed to further elucidate the renal vasodilatory properties of relaxin.

  13. Central Hemodynamics for Management of Arteriosclerotic Diseases.

    PubMed

    Hashimoto, Junichiro

    2017-08-01

    Arteriosclerosis, particularly aortosclerosis, is the most critical risk factor associated with cardiovascular, cerebrovascular, and renal diseases. The pulsatile hemodynamics in the central aorta consists of blood pressure, flow, and stiffness and substantially differs from the peripheral hemodynamics in muscular arteries. Arteriosclerotic changes with age appear earlier in the elastic aorta, and age-dependent increases in central pulse pressure are more marked than those apparent from brachial pressure measurement. Central pressure can be affected by lifestyle habits, metabolic disorders, and endocrine and inflammatory diseases in a manner different from brachial pressure. Central pulse pressure widening due to aortic stiffening increases left ventricular afterload in systole and reduces coronary artery flow in diastole, predisposing aortosclerotic patients to myocardial hypertrophy and ischemia. The widened pulse pressure is also transmitted deep into low-impedance organs such as the brain and kidney, causing microvascular damage responsible for lacunar stroke and albuminuria. In addition, aortic stiffening increases aortic blood flow reversal, which can lead to retrograde embolic stroke and renal function deterioration. Central pressure has been shown to predict cardiovascular events in most previous studies and potentially serves as a surrogate marker for intervention. Quantitative and comprehensive evaluation of central hemodynamics is now available through various noninvasive pressure/flow measurement modalities. This review will focus on the clinical usefulness and mechanistic rationale of central hemodynamic measurements for cardiovascular risk management.

  14. Central Hemodynamics for Management of Arteriosclerotic Diseases

    PubMed Central

    2017-01-01

    Arteriosclerosis, particularly aortosclerosis, is the most critical risk factor associated with cardiovascular, cerebrovascular, and renal diseases. The pulsatile hemodynamics in the central aorta consists of blood pressure, flow, and stiffness and substantially differs from the peripheral hemodynamics in muscular arteries. Arteriosclerotic changes with age appear earlier in the elastic aorta, and age-dependent increases in central pulse pressure are more marked than those apparent from brachial pressure measurement. Central pressure can be affected by lifestyle habits, metabolic disorders, and endocrine and inflammatory diseases in a manner different from brachial pressure. Central pulse pressure widening due to aortic stiffening increases left ventricular afterload in systole and reduces coronary artery flow in diastole, predisposing aortosclerotic patients to myocardial hypertrophy and ischemia. The widened pulse pressure is also transmitted deep into low-impedance organs such as the brain and kidney, causing microvascular damage responsible for lacunar stroke and albuminuria. In addition, aortic stiffening increases aortic blood flow reversal, which can lead to retrograde embolic stroke and renal function deterioration. Central pressure has been shown to predict cardiovascular events in most previous studies and potentially serves as a surrogate marker for intervention. Quantitative and comprehensive evaluation of central hemodynamics is now available through various noninvasive pressure/flow measurement modalities. This review will focus on the clinical usefulness and mechanistic rationale of central hemodynamic measurements for cardiovascular risk management. PMID:28603219

  15. Studies on orientation and rotation parameters of 4179 Toutatis from Chang'e-2 mission

    NASA Astrophysics Data System (ADS)

    Zhao, Yuhui; Ji, Jianghui; Hu, Shoucun

    The ginger-shaped near-Earth asteroid 4179 Toutatis is close to a 4:1 orbital resonance with the Earth and has made close Earth flybys approximately every four years in the recent 20 years. China’s lunar probe Chang’e-2 achieved a successful flyby the Toutatis on 13th Dec 2012 during its most recent flyby of Earth. During the mission, a series of image with high resolution has been obtained. Combined with the radar model of Toutatis, these figures show the attitude of the asteroid from the camera’s point of view and the orientation of it is then deduced based on the attitude of the camera and the relative position between 4179 Toutatis and Chang'e-2 in our works. According to the previous ground-based observations and works on the rotation parameters of Toutatis, this paper studies the rotating rate of the asteroid in accordance with the imaging result of Toutatis by Chang’e-2 and puts forward a correction to the spin rate parameters.

  16. Ambient fine particulate matter alters cerebral hemodynamics in the elderly.

    PubMed

    Wellenius, Gregory A; Boyle, Luke D; Wilker, Elissa H; Sorond, Farzaneh A; Coull, Brent A; Koutrakis, Petros; Mittleman, Murray A; Lipsitz, Lewis A

    2013-06-01

    Short-term elevations in fine particulate matter air pollution (PM2.5) are associated with increased risk of acute cerebrovascular events. Evidence from the peripheral circulation suggests that vascular dysfunction may be a central mechanism. However, the effects of PM2.5 on cerebrovascular function and hemodynamics are unknown. We used transcranial Doppler ultrasound to measure beat-to-beat blood flow velocity in the middle cerebral artery at rest and in response to changes in end-tidal CO2 (cerebral vasoreactivity) and arterial blood pressure (cerebral autoregulation) in 482 participants from the Maintenance of Balance, Independent Living, Intellect, and Zest in the Elderly (MOBILIZE) of Boston study. We used linear mixed effects models with random subject intercepts to evaluate the association between cerebrovascular hemodynamic parameters and mean PM2.5 levels 1 to 28 days earlier adjusting for age, race, medical history, meteorologic covariates, day of week, temporal trends, and season. An interquartile range increase (3.0 µg/m(3)) in mean PM2.5 levels during the previous 28 days was associated with an 8.6% (95% confidence interval, 3.7%-13.8%; P<0.001) higher cerebral vascular resistance and a 7.5% (95% confidence interval, 4.2%-10.6%; P<0.001) lower blood flow velocity at rest. Measures of cerebral vasoreactivity and autoregulation were not associated with PM2.5 levels. In this cohort of community-dwelling seniors, exposure to PM2.5 was associated with higher resting cerebrovascular resistance and lower cerebral blood flow velocity. If replicated, these findings suggest that alterations in cerebrovascular hemodynamics may underlie the increased risk of particle-related acute cerebrovascular events.

  17. A Randomized Trial of Hemodiafiltration and Change in Cardiovascular Parameters

    PubMed Central

    Bots, Michiel L.; van den Dorpel, Marinus A.; Grooteman, Muriel P.C.; Kamp, Otto; Levesque, Renée; ter Wee, Piet M.; Nubé, Menso J.; Blankestijn, Peter J.

    2014-01-01

    Background and objective Increased left ventricular mass (LVM), low ventricular ejection fraction (EF), and high pulse-wave velocity (PWV) relate to overall and cardiovascular mortality in patients with ESRD. The aim of this study was to determine the effect of online hemodiafiltration (HDF) versus low-flux hemodialysis (HD) on LVM, EF, and PWV. Design, setting, participants, & measurements Echocardiography was used to assess LVM and EF in 342 patients in the CONvective TRAnsport STudy followed for up to 4 years. PWV was measured in 189 patients for up to 3 years. Effect of HDF versus HD on LVM, EF, and PWV was evaluated using linear mixed models. Results Patients had a mean age of 63 years, and 61% were male. At baseline, median LVM was 227 g (interquartile range [IQR], 183–279 g), and median EF was 65% (IQR, 55%–72%). Median PWV was 9.8 m/s (IQR, 7.5–12.0 m/s). There was no significant difference between the HDF and HD treatment groups in rate of change in LVM (HDF: change, −0.9 g/yr [95% confidence interval (95% CI), −8.9 to 7.7 g]; HD: change, 12.5 g/yr [95% CI, −3.0 to 27.5 g]; P for difference=0.13), EF (HDF: change, −0.3%/yr [95% CI, −2.3% to 1.8%]; HD: change, −3.4%/yr [95% CI, −5.9% to −0.9%]; P=0.17), or PWV (HDF: change, −0.0 m/s per year [95% CI, −0.4 to 0.4 m/s); HD: change, 0.0 m/s per year [95% CI, −0.3 to 0.2 m/s]; P=0.89). No differences in rate of change between treatment groups were observed for subgroups of age, sex, residual kidney function, dialysis vintage, history of cardiovascular disease, diabetes, or convection volume. Conclusions Treatment with online HDF did not affect changes in LVM, EF, or PWV over time compared with HD. PMID:24408114

  18. Developmental hemodynamic changes in rat embryos at 11 to 15 days of gestation: normal data of blood pressure and the effect of caffeine compared to data from chick embryo.

    PubMed

    Nakazawa, M; Miyagawa, S; Ohno, T; Miura, S; Takao, A

    1988-02-01

    We attempted to measure arterial blood pressure of the rat embryo. The embryo was excised within the uterus and immersed in Hanks' solution at 37 degrees C. The uterus wall and yolk sac were opened to expose the umbilical vessels. The umbilical artery was punctured with a glass micro-pipette, and blood pressure was measured by using a servo-null micro-pressure system. The mean blood pressure was 0.27 +/- 0.05 mm Hg in the embryo at the 11th day of gestation (n = 7), 0.48 +/- 0.03 mm Hg in the 12-day embryos (n = 19), 1.3 +/- 0.08 mm Hg in the 13-day (n = 11), and 2.6 +/- 0.1 mm Hg in the 15-day embryos (n = 10). Heart rate was 84 +/- 11 in 11-day, 122 +/- 3 in 12-day, 192 +/- 7 in 13-day, and 198 +/- 5 in 15-day embryos. These parameters were stable within 10 min after the excision. A comparison of the data with those of the chick embryo of comparable developmental stages revealed that the blood pressure was lower in 11- and 12-day rat embryos than in the chick embryo of Hamburger-Hamilton stages 18 and 21, but this was reversed in the later stages. In the stage 21 chick embryo, intravenous administration of caffeine (60 +/- 9 mg/kg embryo weight) induced an increase in blood pressure by 11 +/- 3% (n = 8), but did not result in a significant increase in dorsal aortic blood flow (6 +/- 6%, n = 9) or in heart rate. In contrast, caffeine (62 +/- 3 mg/kg) increased the heart rate by 8 +/- 2% (n = 10) without changing the blood pressure in the rat embryo of day 12. The velocity of blood flow in the truncus was measured by a pulsed Doppler flowmeter. Caffeine injection increased the mean velocity by 21 +/- 8%). Herein we indicate that measurement of blood pressure in the rat embryo is feasible, but with some limitations, and that there may be qualitative hemodynamic differences between the rat and chick embryos.

  19. [Change of clinical stomatological parameters in ageing (author's transl)].

    PubMed

    Fassauer, H; Schottke, C

    1978-01-01

    Morphological-functional changes occur in the oral cavity also in depended from the age. The morphological changes of the enamel, dentin, dental pulp, periodont, oral mucosa, salivary glands, tongue, maxillary bone and temporo-mandibular-joint change not only the functional cooperation of all parts in the orofacial system. They show effects for the whole body also. A complete gerostomatological standard does not exist for the whole gnathological system. But single indices for some partial components are known. For the judgement of the caries involvement it is possible to use the DMF-index, for which a special gerostomatological type exist. The periodontal diseases are classified adequately to the ARPA-nomenclature. For the judgement of odontolithiasis and oral hygienic conditions you can use the so called odontolith-Index (CI), the OH (oral hygienic debris) and the so called calculus-index (OHI-S). It is refered to different possibilities for classification of dentition with gaps.

  20. Using functional hemodynamic indicators to guide fluid therapy.

    PubMed

    Bridges, Elizabeth

    2013-05-01

    Hemodynamic monitoring has traditionally relied on such static pressure measurements as pulmonary artery occlusion pressure and central venous pressure to guide fluid therapy. Over the past 15 years, however, there's been a shift toward less invasive or noninvasive monitoring methods, which use "functional" hemodynamic indicators that reflect ventilator-induced changes in preload and thereby more accurately predict fluid responsiveness. The author reviews the physiologic principles underlying functional hemodynamic indicators, describes how the indicators are calculated, and discusses when and how to use them to guide fluid resuscitation in critically ill patients.

  1. Hemodynamic determinants of thallium-201 lung uptake in patients during atrial pacing stress

    SciTech Connect

    Brown, K.A.; McKay, R.; Heller, G.V.; Royal, H.D.; Parker, J.A.; Silverman, K.J.; Aroesty, J.

    1986-01-01

    The present investigation was undertaken to define the hemodynamic determinants of lung uptake of thallium-201 (TI-201) in man during stress. Graded tachycardia was induced by atrial pacing with continuous hemodynamic monitoring in 21 patients (6 normal, 15 with coronary artery disease). At peak pacing, 80 MEq (2.2 mCi) of TI-201 was injected intravenously and imaging commenced within 5 minutes. Lung activity was expressed as a percentage of peak myocardial activity on the anterior image (Lung TI-201 Index). The influence of rest, peak and post pacing hemodynamic parameters including cardiac index, pulmonary capillary wedge pressure, left ventricular end-diastolic pressure, pulmonary artery pressure, and heart rate on Lung TI-201 Index was examined using step-wise multiple regression. Change in cardiac index from rest to peak pacing was negatively correlated, while pulmonary capillary wedge pressure at peak pacing was positively correlated to Lung TI-201 Index (combined r value of 0.75). No other parameter had a significant correlation. In summary, lung uptake of TI-201 activity during atrial pacing stress appears to depend on: changes in cardiac output which may determine tissue contact time and thus influence extraction efficiency, and hydrostatic pressure in the pulmonary capillary bed.

  2. Hemodynamic and Light-Scattering Changes of Rat Spinal Cord and Primary Somatosensory Cortex in Response to Innocuous and Noxious Stimuli

    PubMed Central

    He, Ji-Wei; Liu, Hanli; Peng, Yuan Bo

    2015-01-01

    Neuroimaging technologies with an exceptional spatial resolution and noninvasiveness have become a powerful tool for assessing neural activity in both animals and humans. However, the effectiveness of neuroimaging for pain remains unclear partly because the neurovascular coupling during pain processing is not completely characterized. Our current work aims to unravel patterns of neurovascular parameters in pain processing. A novel fiber-optic method was used to acquire absolute values of regional oxy- (HbO) and deoxy-hemoglobin concentrations, oxygen saturation rates (SO2), and the light-scattering coefficients from the spinal cord and primary somatosensory cortex (SI) in 10 rats. Brief mechanical and electrical stimuli (ranging from innocuous to noxious intensities) as well as a long-lasting noxious stimulus (formalin injection) were applied to the hindlimb under pentobarbital anesthesia. Interhemispheric comparisons in the spinal cord and SI were used to confirm functional activation during sensory processing. We found that all neurovascular parameters showed stimulation-induced changes; however, patterns of changes varied with regions and stimuli. Particularly, transient increases in HbO and SO2 were more reliably attributed to brief stimuli, whereas a sustained decrease in SO2 was more reliably attributed to formalin. Only the ipsilateral SI showed delayed responses to brief stimuli. In conclusion, innocuous and noxious stimuli induced significant neurovascular responses at critical centers (e.g., the spinal cord and SI) along the somatosensory pathway; however, there was no single response pattern (as measured by amplitude, duration, lateralization, decrease or increase) that was able to consistently differentiate noxious stimuli. Our results strongly suggested that the neurovascular response patterns differ between brief and long-lasting noxious stimuli, and can also differ between the spinal cord and SI. Therefore, a use of multiple-parameter strategy

  3. Hemodynamic effects of nifedipine tocolysis.

    PubMed

    Yamasato, Kelly; Burlingame, Janet; Kaneshiro, Bliss

    2015-01-01

    To describe the effects of nifedipine tocolysis on blood pressure and heart rate in non-hypertensive women. This was a retrospective study from 2001 to 2011 to compare blood pressures and heart rates among non-hypertensive women on nifedipine tocolysis up to 8 h after nifedipine initiation. Measurements at 20-60 and 61-120 min were compared to assess the differential effects of dosing on hemodynamics and reflected the effects of the initial and complete loading doses, respectively. Charts were reviewed for hypotension-related emergent delivery. One hundred and thirty-eight patients were included. Over the 8-h study interval, mean systolic blood pressure (P < 0.001) and mean diastolic blood pressure (P < 0.001) decreased by 5 mmHg and heart rate increased by 4 b.p.m. (P < 0.001). Systolic and diastolic blood pressures were unchanged from baseline up to 120 min at all doses. Heart rate increased at both 20-60 and 61-120 min when all doses were considered (P < 0.001), but differential dosing effects were not observed. Rates of tachycardia increased (P < 0.001), but rates of hypotension were unchanged. No hypotension-related emergent deliveries occurred. Nifedipine tocolysis was associated with hemodynamic changes in non-hypertensive women. Tachycardia was increased but hypotension was unaffected, supporting the general safety of nifedipine in this setting. © 2014 The Authors. Journal of Obstetrics and Gynaecology Research © 2014 Japan Society of Obstetrics and Gynecology.

  4. [Invasive and minimally invasive hemodynamic monitoring].

    PubMed

    Hansen, Matthias

    2016-10-01

    Advanced hemodynamic monitoring is necessary for adequate management of high-risk patients or patients with derangement of circulation. Studies demonstrate a benefit of early goal directed therapy in unstable cardiopulmonary situations. In these days we have different possibilities of minimally invasive or invasive hemodynamic monitoring. Minimally invasive measurements like pulse conture analysis or pulse wave analysis being less accurate under some circumstances, however only an artery catheter is needed for cardiac output monitoring. Pulmonary artery, transpulmonary thermodilution and lithium dilution technology have acceptable accuracy in cardiac output measurement. For therapy of unstable circulation there are additionally parameters to obtain. The pulmonary artery catheter is the device with the largest rate of complications, used by a trained crew and with a correct indication, his use is unchained justified.

  5. Mathematical simulation of hemodynamical processes and medical technologies

    NASA Astrophysics Data System (ADS)

    Tsitsyura, Nadiya; Novyc'kyy, Victor V.; Lushchyk, Ulyana B.

    2001-06-01

    Vascular pathologies constitute a significant part of human's diseases and their rate tends to increase. Numerous investigations of brain blood flow in a normal condition and in a pathological one has created a new branch of modern medicine -- angioneurology. It combines the information on brain angioarchitecture and on blood supply in a normal condition and in a pathological one. Investigations of a disease's development constitute an important problem of a modern medicine. Cerebrum blood supply is regulated by arterial inflow and venous outflow, but, unfortunately, in the literature available arterial and venous beds are considered separately. This causes an one-sided interpretation of atherosclerotical and discirculatory encefalopathies. As arterial inflow and venous outflow are interrelated, it seems to be expedient to perform a complex estimation of arteriovenous interactions, prove a correlation dependence connection between the beds and find a dependence in a form of mathematical function. The results will be observed clearly in the graphs. There were 139 patients aged from 2 up to 70 examined in the 'Istyna' Scientific Medical Ultrasound Center by means of a Logidop 2 apparatus manufactured by Kranzbuhler, Germany using a technique of cerebral arteries and veins ultrasound location (invented and patented by Ulyana Lushchyk, State Patent of Ukraine N10262 of 19/07/1995). A clinical interpretation of the results obtained was performed. With the help of this technique and ultrasound Dopplerography the blood flow in major head and cervical arteries was investigated. While performing a visual graphic analysis we paid attention to the changes of carotid artery (CA), internal jugular vein (IJV) and supratrochlear artery's (STA) hemodynamical parameters. Generally accepted blood flow parameters: FS -- maximal systolic frequency and FD -- minimal diastolic frequency were measured. The correlation between different combinations of parameters in the vessels mentioned

  6. Theoretical Analysis of the Relative Impact of Obesity on Hemodynamic Stability During Acute Hemorrhagic