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Sample records for cardiac output assessment

  1. Cardiac Output Assessed by Invasive and Minimally Invasive Techniques

    PubMed Central

    Lee, Allison J.; Cohn, Jennifer Hochman; Ranasinghe, J. Sudharma

    2011-01-01

    Cardiac output (CO) measurement has long been considered essential to the assessment and guidance of therapeutic decisions in critically ill patients and for patients undergoing certain high-risk surgeries. Despite controversies, complications and inherent errors in measurement, pulmonary artery catheter (PAC) continuous and intermittent bolus techniques of CO measurement continue to be the gold standard. Newer techniques provide less invasive alternatives; however, currently available monitors are unable to provide central circulation pressures or true mixed venous saturations. Esophageal Doppler and pulse contour monitors can predict fluid responsiveness and have been shown to decrease postoperative morbidity. Many minimally invasive techniques continue to suffer from decreased accuracy and reliability under periods of hemodynamic instability, and so few have reached the level of interchangeability with the PAC. PMID:21776254

  2. Simultaneous separate assessment of the cardiac and LVAD output.

    PubMed

    Chaus, N I; Kislukhin, V V; Smirnov, S S; Ivanov, A S; Zhidkov, I L; Burtsev PYu; Eremenko, A A; Dzemeshkevich, S L; Pentalos, G M; Kolff, W J

    1997-07-01

    The electroimpedance indicators' dilution (EIID) technique was used to study the possibility of a simultaneous separate assessment of the biological heart and LVAD performance in the position of LVB. The experimental part of the research was performed on 5 dogs; an artificial ventricle of the pulsing type (USA) with cusps was used as a pump. The clinical part of the work was conducted on 5 patients after open-heart surgery who had the clinical picture of postcardiotomy cardiogenic shock; a centrifugal pump "Biopump" (Medtronic, USA) was used. The authors have shown a principally important possibility of applying the EIID, technique for studying the performance curves which are the integral derivatives of the work of a specific hybrid system--"the biological heart-assist device". From the practical viewpoint the EIID technique permits in the read time mode to control continuously the part of the pumping function which is assumed by the patient's own heart. This information can serve as the basis for making the prognosis and determining the further tactics of treatment; the restoration of the heart performance or its replacement by transplantation. PMID:9298411

  3. Constant infusion transpulmonary thermodilution for the assessment of cardiac output in exercising humans.

    PubMed

    Calbet, J A L; Mortensen, S P; Munch, G D W; Curtelin, D; Boushel, R

    2016-05-01

    To determine the accuracy and precision of constant infusion transpulmonary thermodilution cardiac output (CITT-Q) assessment during exercise in humans, using indocyanine green (ICG) dilution and bolus transpulmonary thermodilution (BTD) as reference methods, cardiac output (Q) was determined at rest and during incremental one- and two-legged pedaling on a cycle ergometer, and combined arm cranking with leg pedaling to exhaustion in 15 healthy men. Continuous infusions of iced saline in the femoral vein (n = 41) or simultaneously in the femoral and axillary (n = 66) veins with determination of temperature in the femoral artery were used for CITT-Q assessment. CITT-Q was linearly related to ICG-Q (r = 0.82, CITT-Q = 0.876 × ICG-Q + 3.638, P < 0.001; limits of agreement ranging from -1.43 to 3.07 L/min) and BTD-Q (r = 0.91, CITT-Q = 0.822 × BTD + 4.481 L/min, P < 0.001; limits of agreement ranging from -1.01 to 2.63 L/min). Compared with ICG-Q and BTD-Q, CITT-Q overestimated cardiac output by 1.6 L/min (≈ 10% of the mean ICG and BTD-Q values, P < 0.05). For Q between 20 and 28 L/min, we estimated an overestimation < 5%. The coefficient of variation of 23 repeated CITT-Q measurements was 6.0% (CI: 6.1-11.1%). In conclusion, cardiac output can be precisely and accurately determined with constant infusion transpulmonary thermodilution in exercising humans. PMID:25919489

  4. Application of bioreactance for cardiac output assessment during exercise in healthy individuals.

    PubMed

    Elliott, Adrian; Hull, James H; Nunan, David; Jakovljevic, Djordje G; Brodie, David; Ansley, Lesley

    2010-07-01

    In patients with cardiac failure, bioreactance-based cardiac output (CO) monitoring provides a valid non-invasive method for assessing cardiac performance during exercise. The purpose of this study was to evaluate the efficacy of this technique during strenuous exercise in healthy, trained individuals. Fourteen recreational cyclists, mean (SD) age of 34 (8) years and relative peak oxygen uptake of (VO(2)) 56 (6) ml kg(-1) min(-1), underwent incremental maximal exercise testing, whilst CO was recorded continuously using a novel bioreactance-based device (CO(bio)). The CO(bio) was evaluated against relationship with VO(2), theoretical calculation of arterial-venous oxygen difference (C(a - v) O(2)) and level of agreement with an inert gas rebreathing method (CO(rb)) using a Bland-Altman plot. Bioreactance-based CO measurement was practical and straightforward in application, although there was intermittent loss of electrocardiograph signal at high-intensity exercise. At rest and during exercise, CO(bio) was strongly correlated with VO(2) (r = 0.84; P < 0.001), however, there was evidence of systematic bias with CO(bio) providing lower values than CO(rb); mean bias (limits of agreement) -19% (14.6 to -53%). Likewise, calculated (C(a - v) O(2)) was greater when determined using CO(bio) than CO(rb) (P < 0.001), although both devices provided values in excess of those reported in invasive studies. Bioreactance-based determination of CO provides a pragmatic approach to the continuous assessment of cardiac performance during strenuous exercise in trained individuals. Our findings, however, suggest that further work is needed to refine the key measurement determinants of CO using this device to improve measurement accuracy in this setting. PMID:20336309

  5. In vivo validation of cardiac output assessment in non-standard 3D echocardiographic images

    NASA Astrophysics Data System (ADS)

    Nillesen, M. M.; Lopata, R. G. P.; de Boode, W. P.; Gerrits, I. H.; Huisman, H. J.; Thijssen, J. M.; Kapusta, L.; de Korte, C. L.

    2009-04-01

    Automatic segmentation of the endocardial surface in three-dimensional (3D) echocardiographic images is an important tool to assess left ventricular (LV) geometry and cardiac output (CO). The presence of speckle noise as well as the nonisotropic characteristics of the myocardium impose strong demands on the segmentation algorithm. In the analysis of normal heart geometries of standardized (apical) views, it is advantageous to incorporate a priori knowledge about the shape and appearance of the heart. In contrast, when analyzing abnormal heart geometries, for example in children with congenital malformations, this a priori knowledge about the shape and anatomy of the LV might induce erroneous segmentation results. This study describes a fully automated segmentation method for the analysis of non-standard echocardiographic images, without making strong assumptions on the shape and appearance of the heart. The method was validated in vivo in a piglet model. Real-time 3D echocardiographic image sequences of five piglets were acquired in radiofrequency (rf) format. These ECG-gated full volume images were acquired intra-operatively in a non-standard view. Cardiac blood flow was measured simultaneously by an ultrasound transit time flow probe positioned around the common pulmonary artery. Three-dimensional adaptive filtering using the characteristics of speckle was performed on the demodulated rf data to reduce the influence of speckle noise and to optimize the distinction between blood and myocardium. A gradient-based 3D deformable simplex mesh was then used to segment the endocardial surface. A gradient and a speed force were included as external forces of the model. To balance data fitting and mesh regularity, one fixed set of weighting parameters of internal, gradient and speed forces was used for all data sets. End-diastolic and end-systolic volumes were computed from the segmented endocardial surface. The cardiac output derived from this automatic segmentation was validated quantitatively by comparing it with the CO values measured from the volume flow in the pulmonary artery. Relative bias varied between 0 and -17%, where the nominal accuracy of the flow meter is in the order of 10%. Assuming the CO measurements from the flow probe as a gold standard, excellent correlation (r = 0.99) was observed with the CO estimates obtained from image segmentation.

  6. Cardiac output after burn injury.

    PubMed Central

    Porter, J. M.; Shakespeare, P. G.

    1984-01-01

    Cardiac output after burn injury has been measured by the non-invasive method of impedance plethysmography. An initial study of 143 normal subjects was undertaken in order to investigate variations in cardiac output with age. Fifteen patients were monitored during resuscitation after extensive burns. Fourteen patients showed a depression of stroke volume below the lower limits of the normal range, derived from the initial study on normal people. PMID:6691694

  7. Assessment of the effect of vasodilators on the distribution of cardiac output by whole-body Thallium imaging

    SciTech Connect

    Juni, J.E.; Wallis, J.; Diltz, E.; Nicholas, J.; Lahti, D.; Pitt, B.

    1985-05-01

    Vasodilator therapy (tx) of congestive heart failure (CHF) has been shown to be effective in increasing cardiac output (CO) and lowering vascular resistance. Unfortunately, these hemodynamic effects are not usually accompanied by improved peripheral circulation of exercise capacity. To assess the effect of a new vasodilator, Cl-914, on the redistribution of CO to the peripheral circulation, the authors performed testing whole-body thallium scanning (WB-Th) on 6 patients (pts) with severe CHF. Immediately following i.v. injection of 1.5 mCi Th-201, WB scanning was performed from anterior and posterior views. Regions of interest were defined for the peripheral (P) muscles (legs and arms), central torso (C), and splanchnic bed (S). The geometric mean of activity in these regions was calculated from both views. Each pt was studied before tx and again, after 1 week on tx. Invasive measurements revealed that all pts had significant improvements in resting cardiac output (mean increase 49%) and vascular resistance (mean decrease 30%). Unlike other vasodilators, all CI-914 pts had a significant improvement in treadmill exercise capacity (mean increase 54%). WB-Th revealed a significant shift in CO to the peripheral circulation with P:C increased 33.2% (rho= .001) and P:S increased 29% (rho=.01). Vasoactive drugs may significantly alter the relative distribution of cardiac output. WB-Th scanning provides a simple quantitative means of following such changes.

  8. Mathematics and the Heart: Understanding Cardiac Output

    ERIC Educational Resources Information Center

    Champanerkar, Jyoti

    2013-01-01

    This paper illustrates a biological application of the concepts of relative change and area under a curve, from mathematics. We study two biological measures "relative change in cardiac output" and "cardiac output", which are predictors of heart blockages and other related ailments. Cardiac output refers to the quantity of

  9. Mathematics and the Heart: Understanding Cardiac Output

    ERIC Educational Resources Information Center

    Champanerkar, Jyoti

    2013-01-01

    This paper illustrates a biological application of the concepts of relative change and area under a curve, from mathematics. We study two biological measures "relative change in cardiac output" and "cardiac output", which are predictors of heart blockages and other related ailments. Cardiac output refers to the quantity of…

  10. Methods in pharmacology: measurement of cardiac output

    PubMed Central

    Geerts, Bart F; Aarts, Leon P; Jansen, Jos R

    2011-01-01

    Many methods of cardiac output measurement have been developed, but the number of methods useful for human pharmacological studies is limited. The ‘holy grail’ for the measurement of cardiac output would be a method that is accurate, precise, operator independent, fast responding, non-invasive, continuous, easy to use, cheap and safe. This method does not exist today. In this review on cardiac output methods used in pharmacology, the Fick principle, indicator dilution techniques, arterial pulse contour analysis, ultrasound and bio-impedance are reviewed. PMID:21284692

  11. Bioimpedance and bioreactance methods for monitoring cardiac output.

    PubMed

    Jakovljevic, Djordje G; Trenell, Michael I; MacGowan, Guy A

    2014-12-01

    Noninvasive continuous cardiac output monitoring may have wide clinical applications in anaesthesiology, emergency care and cardiology. It can improve outcomes, establish diagnosis, guide therapy and help risk stratification. The present article describes the theory behind the two noninvasive continuous monitoring methods for cardiac output assessment such as bioimpedance and bioreactance. The review discusses the advantages and disadvantages of these methods and highlights the recent method comparison studies. The use of bioimpedance and bioreactance to estimate cardiac output under haemodynamic challenges is also discussed. In particular, the article focuses on performance of the two methods in the assessment of fluid responsiveness using passive leg raising test and cardiac output response to exercise stress testing. PMID:25480768

  12. Comparing the accuracy of ES-BC, EIS-GS, and ES Oxi on body composition, autonomic nervous system activity, and cardiac output to standardized assessments

    PubMed Central

    Lewis, John E; Tannenbaum, Stacey L; Gao, Jinrun; Melillo, Angelica B; Long, Evan G; Alonso, Yaima; Konefal, Janet; Woolger, Judi M; Leonard, Susanna; Singh, Prabjot K; Chen, Lawrence; Tiozzo, Eduard

    2011-01-01

    Background and purpose The Electro Sensor Complex (ESC) is software that combines three devices using bioelectrical impedance, galvanic skin response, and spectrophotometry: (1) ES-BC (Electro Sensor-Body Composition; LD Technology, Miami, FL) to assess body composition, (2) EIS-GS (Electro Interstitial Scan-Galvanic Skin; LD Technology) to predict autonomic nervous system activity, and (3) ES Oxi (Electro Sensor Oxi; LD Technology) to assess cardiac output. The objective of this study was to compare each to a standardized assessment: ES-BC to dual-energy X-ray absorptiometry (DXA), EIS-GS to heart rate variability, and ES Oxi to BioZ Dx Diagnostic System (BioZ Dx; SonoSite Inc, Bothell, WA). Patients and methods The study was conducted in two waves. Fifty subjects were assessed for body composition and autonomic nervous system activity. Fifty-one subjects were assessed for cardiac output. Results We found adequate relative and absolute agreement between ES-BC and DXA for fat mass (r = 0.97, P < 0.001) with ES-BC overestimating fat mass by 0.1 kg and for body fat percentage (r = 0.92, P < 0.001) with overestimation of fat percentage by 0.4%. For autonomic nervous system activity, we found marginal relative agreement between EIS-GS and heart rate variability by using EIS-GS as the predictor in a linear regression equation (adjusted R2 = 0.56, P = 0.03). For cardiac output, adequate relative and absolute agreement was found between ES Oxi and BioZ Dx at baseline (r = 0.60, P < 0.001), after the first exercise stage (r = 0.79, P < 0.001), and after the second exercise stage (r = 0.86, P < 0.001). Absolute agreement was found at baseline and after both bouts of exercise; ES Oxi overestimated baseline and stage 1 exercise cardiac output by 0.3 L/minute and 0.1 L/minute, respectively, but exactly estimated stage 2 exercise cardiac output. Conclusion ES-BC and ES Oxi accurately assessed body composition and cardiac output compared to standardized instruments, whereas EIS-GS showed marginal predictive ability for autonomic nervous system activity. The ESC software managing the three devices would be useful to help detect complications related to metabolic syndrome, diabetes, and cardiovascular disease and to noninvasively and rapidly manage treatment follow-up. PMID:22915943

  13. Evaluation of noninvasive cardiac output methods during exercise

    NASA Technical Reports Server (NTRS)

    Moore, Alan D.; Barrows, Linda H.; Rashid, Michael; Siconolfi, Steven F.

    1992-01-01

    Noninvasive techniques to estimate cardiac output (Qc) will be used during future space flight. This retrospective literature survey compared the Qc techniques of carbon dioxide rebreathing (CO2-R), CO2 single breath (CO2-S), Doppler (DOP), impedance (IM), and inert gas (IG: acetylene or nitrous oxide) to direct (DIR) assessments measured at rest and during exercise.

  14. Pathophysiology of Post-Operative Low Cardiac Output Syndrome.

    PubMed

    Epting, Conrad L; McBride, Mary E; Wald, Eric L; Costello, John M

    2016-01-01

    Low cardiac output syndrome frequently complicates the post-operative care of infants and children following cardiac surgery. The onset of low cardiac output follows a predictable course in the hours following cardiopulmonary bypass, as myocardial performance declines in the face of an elevated demand for cardiac output. When demand outstrips supply, shock ensues, and early recognition and intervention can decrease mortality. Multifactorial in etiology, this article will discuss the pathophysiology of low cardiac output syndrome, including myocardial depression following bypass, altered cardiac loading conditions, and inflammation driving a hypermetabolic state. Contributions from altered neurohormonal, thyroid, and adrenal axes will also be discussed. Sources included the clinical experiences of four cardiac intensivists, supported throughout by primary sources and relevant reviews obtained through PubMed searches and from seminal textbooks in the field. This article addresses the second of eight topics comprising the special issue entitled "Pharmacologic strategies with afterload reduction in low cardiac output syndrome after pediatric cardiac surgery". PMID:26463989

  15. Methods and apparatus for determining cardiac output

    NASA Technical Reports Server (NTRS)

    Cohen, Richard J. (Inventor); Mukkamala, Ramakrishna (Inventor); Sherman, Derin A. (Inventor)

    2010-01-01

    The present invention provides methods and apparatus for determining a dynamical property of the systemic or pulmonary arterial tree using long time scale information, i.e., information obtained from measurements over time scales greater than a single cardiac cycle. In one aspect, the invention provides a method and apparatus for monitoring cardiac output (CO) from a single blood pressure signal measurement obtained at any site in the systemic or pulmonary arterial tree or from any related measurement including, for example, fingertip photoplethysmography.According to the method the time constant of the arterial tree, defined to be the product of the total peripheral resistance (TPR) and the nearly constant arterial compliance, is determined by analyzing the long time scale variations (greater than a single cardiac cycle) in any of these blood pressure signals. Then, according to Ohm's law, a value proportional to CO may be determined from the ratio of the blood pressure signal to the estimated time constant. The proportional CO values derived from this method may be calibrated to absolute CO, if desired, with a single, absolute measure of CO (e.g., thermodilution). The present invention may be applied to invasive radial arterial blood pressure or pulmonary arterial blood pressure signals which are routinely measured in intensive care units and surgical suites or to noninvasively measured peripheral arterial blood pressure signals or related noninvasively measured signals in order to facilitate the clinical monitoring of CO as well as TPR.

  16. Cardiac output monitoring by echocardiography: should we pass on Swan-Ganz catheters?

    PubMed Central

    Perrino, A. C.

    1993-01-01

    Transesophageal echocardiography offers a noninvasive technique for the continuous monitoring of cardiac performance. The combination of 2-dimensional echocardiography and Doppler velocitometry provide assessment of cardiac anatomy, valve function and, ventricular loading conditions. Although transesophageal echocardiography has become accepted for perioperative monitoring, it is typically used in conjunction with Swan-Ganz catheterization. To supplant Swan-Ganz catheters, an echocardiographic technique to monitor cardiac output is necessary. Despite considerable effort to achieve this goal, a satisfactory technique has been difficult to realize. This paper discusses the role of cardiac output monitoring in perioperative care and critically examines echocardiographic techniques for cardiac output monitoring. Images Figure 4 Figure 7 Figure 10 PMID:7825341

  17. Cardiac Risk Assessment

    MedlinePlus

    ... helpful? Formal name: Cardiac Risk Assessment Related tests: Lipid Profile , VLDL Cholesterol , hs-CRP , Lp(a) Overview | Common ... on Coronary artery disease: Tests and diagnosis .) The lipid profile is the most important blood test for cardiac ...

  18. Noninvasive cardiac output measurements in patients with pulmonary hypertension.

    PubMed

    Rich, Jonathan D; Archer, Stephen L; Rich, Stuart

    2013-07-01

    Pulmonary hypertension (PH) is characterised by a progressive decline in cardiac output (CO) and right heart failure. NICOM® (noninvasive cardiac output monitor) is a bioreactance-based technology that has been broadly validated, but its specific application in right heart failure and PH is unknown. Cardiac catheterisation was performed in 50 consecutive patients with PH. CO measurements were performed using three different methods (thermodilution, Fick and NICOM) at baseline and after vasodilator challenge. We compared the precision (coefficient of variation) and accuracy of NICOM compared to thermodilution and Fick. The mean CO (L·min(-1)) at baseline as measured by the three methods was 4.73±1.15 (NICOM), 5.69±1.74 (thermodilution) and 4.84±1.39 (Fick). CO measured by NICOM was more precise than by thermodilution (3.5±0.3% versus 9.6±6.1%, p<0.001). Bland-Altman analyses comparing NICOM to thermodilution and Fick revealed bias and 95% limits of agreement that were comparable to those comparing Fick to thermodilution. All three CO methods detected an increase in CO in response to vasodilator challenge. CO measured via NICOM is precise and reliably measures CO at rest and changes in CO with vasodilator challenge in patients with PH. NICOM may allow for the noninvasive haemodynamic assessment of patients with PH and their response to therapy. PMID:23100501

  19. Noninvasive continuous cardiac output monitoring in perioperative and intensive care medicine.

    PubMed

    Saugel, B; Cecconi, M; Wagner, J Y; Reuter, D A

    2015-04-01

    The determination of blood flow, i.e. cardiac output, is an integral part of haemodynamic monitoring. This is a review on noninvasive continuous cardiac output monitoring in perioperative and intensive care medicine. We present the underlying principles and validation data of the following technologies: thoracic electrical bioimpedance, thoracic bioreactance, vascular unloading technique, pulse wave transit time, and radial artery applanation tonometry. According to clinical studies, these technologies are capable of providing cardiac output readings noninvasively and continuously. They, therefore, might prove to be innovative tools for the assessment of advanced haemodynamic variables at the bedside. However, for most technologies there are conflicting data regarding the measurement performance in comparison with reference methods for cardiac output assessment. In addition, each of the reviewed technology has its own limitations regarding applicability in the clinical setting. In validation studies comparing cardiac output measurements using these noninvasive technologies in comparison with a criterion standard method, it is crucial to correctly apply statistical methods for the assessment of a technology's accuracy, precision, and trending capability. Uniform definitions for 'clinically acceptable agreement' between innovative noninvasive cardiac output monitoring systems and criterion standard methods are currently missing. Further research must aim to further develop the different technologies for noninvasive continuous cardiac output determination with regard to signal recording, signal processing, and clinical applicability. PMID:25596280

  20. Reproducibility of cardiac power output and other cardiopulmonary exercise indices in patients with chronic heart failure.

    PubMed

    Jakovljevic, Djordje G; Seferovic, Petar M; Nunan, David; Donovan, Gay; Trenell, Michael I; Grocott-Mason, Richard; Brodie, David A

    2012-02-01

    Cardiac power output is a direct measure of overall cardiac function that integrates both flow- and pressure-generating capacities of the heart. The present study assessed the reproducibility of cardiac power output and other more commonly reported cardiopulmonary exercise variables in patients with chronic heart failure. Metabolic, ventilatory and non-invasive (inert gas re-breathing) central haemodynamic measurements were undertaken at rest and near-maximal exercise of the modified Bruce protocol in 19 patients with stable chronic heart failure. The same procedure was repeated 7 days later to assess reproducibility. Cardiac power output was calculated as the product of cardiac output and mean arterial pressure. Resting central haemodynamic variables demonstrate low CV (coefficient of variation) (ranging from 3.4% for cardiac output and 5.6% for heart rate). The CV for resting metabolic and ventilatory measurements ranged from 8.2% for respiratory exchange ratio and 14.2% for absolute values of oxygen consumption. The CV of anaerobic threshold, peak oxygen consumption, carbon dioxide production and respiratory exchange ratio ranged from 3.8% (for anaerobic threshold) to 6.4% (for relative peak oxygen consumption), with minute ventilation having a CV of 11.1%. Near-maximal exercise cardiac power output and cardiac output had CVs of 4.1 and 2.2%, respectively. Cardiac power output demonstrates good reproducibility suggesting that there is no need for performing more than one cardiopulmonary exercise test. As a direct measure of cardiac function (dysfunction) and an excellent prognostic marker, it is strongly advised in the assessment of patients with chronic heart failure undergoing cardiopulmonary exercise testing. PMID:21883095

  1. Sham-feeding decreases cardiac output in normal subjects.

    PubMed

    Andersen, H B; Jensen, E W; Madsbad, S; Nielsen, S L; Burcharth, F; Christensen, N J

    1992-07-01

    The cardiovascular effect of sham-feeding was measured in seven healthy non-obese human subjects by the Fick principle using the carbon dioxide rebreathing method. The subjects were resting in the sitting position and were exposed to the sight and smell but not the taste of a breakfast meal. Cardiac output decreased significantly from a mean value of 4.0 1 min-1 to 3.5 1 min-1 during sham-feeding (Friedman, P = 0.004). The cardiac output returned to basal values in all seven subjects when the sensory stimulus was removed. The decrease in cardiac output was due to a decreased stroke volume, whereas heart rate and blood pressure did not change. The mechanism of the decrease in cardiac output during sham-feeding remains to be established. PMID:1505165

  2. Red cell volume and cardiac output in anaemic preterm infants.

    PubMed Central

    Hudson, I; Cooke, A; Holland, B; Houston, A; Jones, J G; Turner, T; Wardrop, C A

    1990-01-01

    To test the hypothesis that haemoglobin concentration is a poor predictor of benefit from transfusion in preterm infants, and that red cell volume is the most important indicator of anaemia, 24 preterm infants receiving red cell transfusions had red cell volume, haemoglobin concentration, and cardiac output measured before and after transfusion. Red cell volume was measured either using dilution of autologous fetal haemoglobin with donor adult haemoglobin, or with a new technique using biotin as a red cell label. The two techniques give similar results. Mean (SD) values before transfusion were 27.4 (13.3), and after transfusion 45.0 (13.7) ml/kg. Cardiac output was measured using imaging and Doppler ultrasonography, and fell with transfusion from mean 286 (121) to 251 (95.6) ml/kg/min. The red cell volume before transfusion correlated well with changes in cardiac output following transfusion, infants with a red cell volume before transfusion of less than 25 ml/kg showing a fall in cardiac output, and those with a red cell volume of greater than 25 ml/kg not showing a significant fall. There was no correlation between haemoglobin concentration, packed cell volume, or change in packed cell volume with changes in cardiac output after transfusion. A red cell volume of 25 ml/kg seems to be critical in preterm infants with anaemia, and infants with values below this are those most likely to benefit from transfusion. PMID:2386399

  3. Evaluation of heavy water for indicator dilution cardiac output measurement

    SciTech Connect

    Schreiner, M.S.; Leksell, L.G.; Neufeld, G.R. )

    1989-10-01

    We evaluated deuterium oxide (D2O) as a tracer for cardiac output measurements. Cardiac output measurements made by thermodilution were compared with those made by indicator dilution with D2O and indocyanine green as tracers. Five triplicate measurements for each method were made at intervals of 30 minutes in each of 9 anesthetized, mechanically ventilated goats. Cardiac output ranged between 0.68 and 3.79 L/min. The 45 data points yielded a correlation coefficient of 0.948 for the comparison of D2O indicator dilution cardiac output measurements with thermodilution measurements and a linear regression slope of 1.046. D2O indicator dilution measurements were biased by -0.11 +/- 0.22 L/min compared with thermodilution measurements and had a standard deviation of +/- 0.12 L/min for triplicate measurements. Hematocrits ranging between 20 and 50 vol% had no effect on optical density for D2O. D2O is more stable than indocyanine green and approximately one-tenth the price (40 cents per injection compared with $4). The basic instrumentation cost of approximately $9,000 is an additional initial expense, but provides the ability to perform pulmonary extravascular water measurements with a double-indicator dilution technique. D2O has potential as a tracer for the clinical determination of indicator dilution cardiac output measurements and pulmonary extravascular water measurements.

  4. Cardiac output estimation using pulmonary mechanics in mechanically ventilated patients.

    PubMed

    Sundaresan, Ashwath; Chase, J Geoffrey; Hann, Christopher E; Shaw, Geoffrey M

    2010-01-01

    The application of positive end expiratory pressure (PEEP) in mechanically ventilated (MV) patients with acute respiratory distress syndrome (ARDS) decreases cardiac output (CO). Accurate measurement of CO is highly invasive and is not ideal for all MV critically ill patients. However, the link between the PEEP used in MV, and CO provides an opportunity to assess CO via MV therapy and other existing measurements, creating a CO measure without further invasiveness.This paper examines combining models of diffusion resistance and lung mechanics, to help predict CO changes due to PEEP. The CO estimator uses an initial measurement of pulmonary shunt, and estimations of shunt changes due to PEEP to predict CO at different levels of PEEP. Inputs to the cardiac model are the PV loops from the ventilator, as well as the oxygen saturation values using known respiratory inspired oxygen content. The outputs are estimates of pulmonary shunt and CO changes due to changes in applied PEEP. Data from two published studies are used to assess and initially validate this model.The model shows the effect on oxygenation due to decreased CO and decreased shunt, resulting from increased PEEP. It concludes that there is a trade off on oxygenation parameters. More clinically importantly, the model also examines how the rate of CO drop with increased PEEP can be used as a method to determine optimal PEEP, which may be used to optimise MV therapy with respect to the gas exchange achieved, as well as accounting for the impact on the cardiovascular system and its management. PMID:21108836

  5. Cardiac output measurement using a modified carbon dioxide Fick method: comparison analysis with pulmonary artery catheter method and pulse induced contour cardiac output method

    PubMed Central

    Li, Tong; Cai, Hongliu; Pan, Hui; Pu, Qibin

    2015-01-01

    Objectives: In the present study, cardiac output in mechanically ventilated patients were determined using three methods including modified CO2-Fick (mCO2F), pulmonary artery catheter (PAC), and pulse induced contour cardiac output (PiCCO) methods and the results were compared to assess the effectiveness of mCO2F method in measuring the cardiac output. Method: Mechanically ventilated and hemodynamically unstable patients (n=39) were sedated and intubated with Swan-Ganz or PiCCO arterial catheters. At the beginning of the experiment and at 4 h after the experiment, the CO2 concentration in expiratory air was measured through a CO2 monitor and it was used further in the cardiac output calculation using mCO2F method. The cardiac output was also determined using PAC and PiCCO methods. Results: The cardiac output determined by PAC and mCO2F method was not significantly (P>0.05) different [5.53±2.85 L.min-1 (PAC) and 5.96±2.92 L.min-1 (mCO2F)] at the beginning of the experiment and [6.22±2.7 L.min-1 (PAC) and 6.36±2.35 L.min-1 (mCO2F)] at 4 h after the experiment; however, they were highly correlated (r=0.939 and 0.908, P<0.001). The cardiac output determined by PiCCO and mCO2F method was also not significantly (P>0.05) different [6.05±2.49 L.min-1 (PiCCO) and 5.44±1.64 L.min-1 (mCO2F)] at the beginning of the experiment, and [6.17±2.04 L.min-1 (PiCCO) and 5.70±1.72 L.min-1 (mCO2F)] at 4 h after the experiment; however, they were highly correlated (r=0.776 and 0.832, P<0.001). Conclusion: The mCO2F method could accurately measure the cardiac output in mechanically ventilated patients without using any expensive equipment’s and invasive procedures. PMID:26064245

  6. Continuous cardiac output measurements in the perioperative period.

    PubMed

    Jakobsen, C J; Melsen, N C; Andresen, E B

    1995-05-01

    Management of critically ill patients is based on knowledge of fundamental physiologic variables. Automatized and continuous measurement of these variables is preferable. A new system based upon the thermodilution method has been developed to measure cardiac output automatically and continuously. We evaluated the system in the potentially unstable perioperative period with possible great and rapid changes in cardiac output. Twenty patients, scheduled for open heart or abdominal aortic aneurysm surgery, were included in the study, which was approved by the local ethical committee. The patients were monitored up to 30 hours. At random intervals five, iced, bolus thermodilution cardiac output (BCO) determinations were made and compared to the continuous cardiac output measurements (CCO). Two hundred and thirty-one pairs of data were obtained. The cardiac outputs ranged from 2.5-14.9 l.min-1. The absolute bias was 0.31 l.min-1 (95% limits of agreement -14 l.min-1 to 2.0 l.min-1). The mean relative error was 4.7% with a standard deviation of the relative error of 15.4%. The linear regression was represented by: CCO = 1,1352.BCO-0.36. The correlation coefficient R was 0.90 (P < 0.001). In conclusion, the CCO measurement technique is a promising clinical method. The method is straightforward, requires no calibration, is independent of vascular geometry and measures with its limitations volumetric flow. Finally automatic and continuous patient monitoring provides more information and has potential to reveal previously undetected haemodynamic events. PMID:7676783

  7. Management of the Low Cardiac Output Syndrome Following Surgery for Congenital Heart Disease.

    PubMed

    Chandler, Heather K; Kirsch, Roxanne

    2016-01-01

    The purpose of this review is to discuss the management of the low cardiac output syndrome (LCOS) following surgery for congenital heart disease. The LCOS is a well-recognized, frequent post-operative complication with an accepted collection of hemodynamic and physiologic aberrations. Approximately 25% of children experience a decrease in cardiac index of less than 2 L/min/m2 within 6-18 hours after cardiac surgery. Post-operative strategies that may be used to manage patients as risk for or in a state of low cardiac output include the use of hemodynamic monitoring, enabling a timely and accurate assessment of cardiovascular function and tissue oxygenation; optimization of ventricular loading conditions; the judicious use of inotropic agents; an appreciation of and the utilization of positive pressure ventilation for circulatory support; and, in some circumstances, mechanical circulatory support. All interventions and strategies should culminate in improving the relationship between oxygen supply and demand, ensuring adequate tissue oxygenation. PMID:26585039

  8. Measurement of cardiac output from dynamic pulmonary circulation time CT

    SciTech Connect

    Yee, Seonghwan; Scalzetti, Ernest M.

    2014-06-15

    Purpose: To introduce a method of estimating cardiac output from the dynamic pulmonary circulation time CT that is primarily used to determine the optimal time window of CT pulmonary angiography (CTPA). Methods: Dynamic pulmonary circulation time CT series, acquired for eight patients, were retrospectively analyzed. The dynamic CT series was acquired, prior to the main CTPA, in cine mode (1 frame/s) for a single slice at the level of the main pulmonary artery covering the cross sections of ascending aorta (AA) and descending aorta (DA) during the infusion of iodinated contrast. The time series of contrast changes obtained for DA, which is the downstream of AA, was assumed to be related to the time series for AA by the convolution with a delay function. The delay time constant in the delay function, representing the average time interval between the cross sections of AA and DA, was determined by least square error fitting between the convoluted AA time series and the DA time series. The cardiac output was then calculated by dividing the volume of the aortic arch between the cross sections of AA and DA (estimated from the single slice CT image) by the average time interval, and multiplying the result by a correction factor. Results: The mean cardiac output value for the six patients was 5.11 (l/min) (with a standard deviation of 1.57 l/min), which is in good agreement with the literature value; the data for the other two patients were too noisy for processing. Conclusions: The dynamic single-slice pulmonary circulation time CT series also can be used to estimate cardiac output.

  9. Continuous cardiac output monitoring by peripheral blood pressure waveform analysis.

    PubMed

    Mukkamala, Ramakrishna; Reisner, Andrew T; Hojman, Horacio M; Mark, Roger G; Cohen, Richard J

    2006-03-01

    A clinical method for monitoring cardiac output (CO) should be continuous, minimally invasive, and accurate. However, none of the conventional CO measurement methods possess all of these characteristics. On the other hand, peripheral arterial blood pressure (ABP) may be measured reliably and continuously with little or no invasiveness. We have developed a novel technique for continuously monitoring changes in CO by mathematical analysis of a peripheral ABP waveform. In contrast to the previous techniques, our technique analyzes the ABP waveform over time scales greater than a cardiac cycle in which the confounding effects of complex wave reflections are attenuated. The technique specifically analyzes 6-min intervals of ABP to estimate the pure exponential pressure decay that would eventually result if pulsatile activity abruptly ceased (i.e., after the high frequency wave reflections vanish). The technique then determines the time constant of this exponential decay, which equals the product of the total peripheral resistance and the nearly constant arterial compliance, and computes proportional CO via Ohm's law. To validate the technique, we performed six acute swine experiments in which peripheral ABP waveforms and aortic flow probe CO were simultaneously measured over a wide physiologic range. We report an overall CO error of 14.6%. PMID:16532772

  10. Measurement of cardiac output in children by bioreactance.

    PubMed

    Ballestero, Yolanda; López-Herce, Jesús; Urbano, Javier; Solana, Maria José; Botrán, Marta; Bellón, Jose M; Carrillo, Angel

    2011-04-01

    The objective of this study was to evaluate a new bioreactance method for noninvasive cardiac output (CO) measurement (NICOM) in children. Ten patients between 1 and 144 months of age and with no hemodynamic disturbances were studied. Using bioreactance, heart rate (HR), mean arterial pressure (MAP), and cardiac index (CI) measurements were made every 6-8 h. CI was 2.4 ± 1.03 l/min/1.73 m(2) (range 1-4.9 l/min/1.73 m(2)); There were significant correlations between CI and age (r = 0.50, P = 0.003), weight (r = 0.66, P < 0.001), and MAP (r = 0.369, P = 0.037). Significant differences in CI (P < 0.001) were detected between children weighing <10 kg (1.9 ± 0.73 l/min/1.73 m(2); range 1-3.2), 10-20 kg (2.07 ± 0.7 l/min/1.73 m(2); range 1-3.6), and >20 kg (3.7 ± 0.8 l/min/1.73 m(2); range 2.4-4.9). We conclude that the CI measured by bioreactance in children varies with the age and weight of the patients and is lower than the normal range in a large percentage of measurements. These data suggest that this method is not useful for evaluating CI in small children. PMID:21318463

  11. Maximal Cardiac Output Determines 6 Minutes Walking Distance in Pulmonary Hypertension

    PubMed Central

    Deboeck, Gal; Taboada, Dolores; Hagan, Guy; Treacy, Carmen; Page, Kathy; Sheares, Karen; Naeije, Robert; Pepke-Zaba, Joanna

    2014-01-01

    Purpose The 6 minutes walk test (6MWT) is often shown to be the best predictor of mortality in pulmonary hypertension (PH) probably because it challenges the failing heart to deliver adequate cardiac output. We hypothesised that the 6MWT elicits maximal cardiac output as measured during a maximal cardiopulmonary exercise testing (CPET). Methods 18 patients with chronic thromboembolic pulmonary hypertension (n?=?12) or pulmonary arterial hypertension (n?=?6) and 10 healthy subjects performed a 6MWT and CPET with measurements of cardiac output (non invasive rebreathing device) before and directly after exercise. Heart rate was measured during 6MWT with a cardiofrequence meter. Results Cardiac output and heart rate measured at the end of the 6MWT were linearly related to 6MW distance (meanSD: 49087 m). Patients with a high NT-pro-BNP achieve a maximum cardiac output during the 6MWT, while in normal subjects and in patients with a low-normal NT-proBNP, cardiac output at the end of a 6MWT was lower than achieved at maximum exercise during a CPET. In both cases, heart rate is the major determinant of exercise-induced increase in cardiac output. However, stroke volume increased during CPET in healthy subjects, not in PH patients. Conclusion Maximal cardiac output is elicited by 6MWT in PH patients with failing right ventricle. Cardiac output increase is dependent on chronotropic response in patients with PH. PMID:24647561

  12. Minimally invasive or noninvasive cardiac output measurement: an update.

    PubMed

    Sangkum, Lisa; Liu, Geoffrey L; Yu, Ling; Yan, Hong; Kaye, Alan D; Liu, Henry

    2016-06-01

    Although cardiac output (CO) by pulmonary artery catheterization (PAC) has been an important guideline in clinical management for more than four decades, some studies have questioned the clinical efficacy of CO in certain patient populations. Further, the use of CO by PAC has been linked to numerous complications including dysrhythmia, infection, rupture of pulmonary artery, injury to adjacent arteries, embolization, pulmonary infarction, cardiac valvular damage, pericardial effusion, and intracardiac catheter knotting. The use of PAC has been steadily declining over the past two decades. Minimally invasive and noninvasive CO monitoring have been studied in the past two decades with some evidence of efficacy. Several different devices based on pulse contour analysis are available currently, including the uncalibrated FloTrac/Vigileo system and the calibrated PiCCO and LiDCO systems. The pressure-recording analytical method (PRAM) system requires only an arterial line and is commercially available as the MostCare system. Transesophageal echocardiography (TEE) can measure CO by non-Doppler- or Doppler-based methods. The partial CO2 rebreathing technique, another method to measure CO, is marketed by Novametrix Medical Systems as the NICO system. Thoracic electrical bioimpedance (TEB) and electric bioreactance (EB) are totally noninvasive CO monitoring. Nexfin HD and the newer ClearSight systems are examples of noninvasive CO monitoring devices currently being marketed by Edwards Lifesciences. The developing focus in CO monitoring devices appears to be shifting to tissue perfusion and microcirculatory flow and aimed more at markers that indicate the effectiveness of circulatory and microcirculatory resuscitations. PMID:26961819

  13. Thermodynamics of the heart: Relation between cardiac output and oxygen consumption

    NASA Astrophysics Data System (ADS)

    Uehara, Mituo; Sakane, Kumiko K.; Bertolotti, Simone A.

    2008-06-01

    A thermodynamic approach is used to derive a relation between cardiac output and rate of oxygen consumption. As an example, the relation is used to calculate the cardiac output of a young woman exercising on a treadmill. The results can be understood by undergraduates without any previous knowledge of human physiology.

  14. Comparison of Cardiac Output Responses to 2,4-Dinitrophenol-Induced Hypermetabolism and Muscular Work

    PubMed Central

    Liang, Chang-Seng; Hood, William B.

    1973-01-01

    Both electrically induced exercise and infusion of 2,4-dinitrophenol (DNP) increased oxygen consumption and tissue metabolism in chloralose-anesthetized dogs. Cardiac output increased with oxygen consumption at the same rate in both experimental conditions. The increase in cardiac output induced by exercise was, as expected, accompanied by increases in both lactate-to-pyruvate ratio and “excess lactate” in arterial blood. However, these parameters did not increase after DNP infusion until the rate of oxygen consumption had increased four- to fivefold, perhaps due to facilitation of mitochondrial electron transport by DNP. Anaerobic tissue metabolism therefore probably did not contribute significantly to increased cardiac output during the mild-to-moderate tissue hypermetabolism induced by DNP. The increased cardiac output may have been the result of metabolic changes common to both exercise and DNP infusion; muscular activity alone may not have been the primary determinant of the cardiac output response during exercise. PMID:4727459

  15. Noninvasive measurements of cardiac output in sheep: an improved thermometry method.

    PubMed

    Serikov, V B; Jerome, E H

    1997-10-01

    In 25 sheep and 5 goats, which were anesthetized, intubated and mechanically ventilated a sudden decrease in the inspired gas humidity was used to cool the lungs. The dynamics of the temperature of expired gas and its relationship to ventilation rate and cardiac output measured by thermodilution were investigated. In six animals minute ventilation was changed at a stable cardiac output and in 14 animals cardiac output was changed by infusion of saline or by bleeding at a constant ventilation. The difference between the blood temperature and the expired gas temperature at a steady state is proportional to minute ventilation and is inversely proportional to the cardiac output. The inverse time constant of the decay of temperature of the expired gas is proportional to the cardiac output and does not depend on ventilation. The lungs function as a natural humidifier of the respiratory gases with an inner heat source from the pulmonary circulation and an outer heat sink to the expired gas. A simple lumped heat capacity model of non-steady state heat exchange in the lungs was developed, which may be used as a basis for the non-invasive method for determining cardiac output. The coefficient of the lung thermal conductivity (KT/(rho WCpW) = 0.156 +/- 0.056) was determined and applied to measure cardiac output in a separate group, designed as a prospective study. When calculations of cardiac output were done based on the lung mass, estimated from the body weight (12 g/kg), bias and precision compared with thermodilution were -0.27 l/min and 0.38 l/min, respectively in 15 animals. Measurements of blood flow by the air thermometry correlated very well with thermodilution cardiac output (r = 0.92). Thermometry of the expired gas is a promising approach to measure the cardiac output non-invasively. PMID:9457695

  16. Mechanisms Regulating the Cardiac Output Response to Cyanide Infusion, a Model of Hypoxia

    PubMed Central

    Liang, Chang-seng; Huckabee, William E.

    1973-01-01

    When tissue metabolic changes like those of hypoxia were induced by intra-aortic infusion of cyanide in dogs, cardiac output began to increase after 3 to 5 min, reached a peak (220% of the control value) at 15 min, and returned to control in 40 min. This pattern of cardiac output rise was not altered by vagotomy with or without atropine pretreatment. However, this cardiac output response could be differentiated into three phases by pretreating the animals with agents that block specific activities of the sympatho-adrenal system. First, ganglionic blockade produced by mecamylamine or sympathetic nerve blockade by bretylium abolished the middle phase of the cardiac output seen in the untreated animal, but early and late phases still could be discerned. Second, beta-adrenergic receptor blockade produced by propranolol shortened the total duration of the cardiac output rise by abolishing the late phase. Third, when given together, propranolol and mecamylamine (or bretylium) prevented most of the cardiac output rise that follows the early phase. When cyanide was given to splenectomized dogs, the duration of the cardiac output response was not shortened, but the response became biphasic, resembling that seen after chemical sympathectomy. A similar biphasic response of the cardiac output also resulted from splenic denervation; sham operation or nephrectomy had no effect on the monophasic pattern of the normal response. Splenic venous blood obtained from cyanide-treated dogs, when infused intraportally, caused an increase in cardiac output in recipient dogs; similar infusion of arterial blood had no effects. These results suggest that the cardiac output response to cyanide infusion consists of three components: an early phase, related neither to the autonomic nervous system nor to circulating catecholamines; a middle phase, caused by a nonadrenergic humoral substance released from the spleen by sympathetic stimulation; and a late phase, dependent upon adrenergic receptors but not upon sympathetic transmission. PMID:4750445

  17. Continuous monitoring of cardiac output from TCG signals.

    PubMed

    Keenan, D B

    2004-01-01

    Continuous measurement of cardiac output (CO) is an important and difficult measure to obtain in an ambulatory environment. A novel ambulatory monitoring system (LifeShirt, VivoMetrics, Inc., Ventura, CA, USA) with three Inductive Plethysmographic (IP) sensors embedded in a garment, enables continuous monitoring of respiration from the ribcage and abdomen areas, and captures thoracocardiograph (TCG) signals from the thorax at the level of the left ventricle. This TCG signal provides a non-invasive measure of the volumetric contractions of the heart. The raw TCG signal must undergo extensive signal processing and digital filtering to extract a volume curve similar to the ventricular volume curve obtained through echocardiography. Typically the respiratory component has an amplitude of over twenty times that of the stroke volume curve. This investigation compares various signal processing algorithms such as spectral subtraction and adaptive filtering to separate these 2 components, which can occupy the same frequency band. These algorithms make use of the ribcage and abdominal signals to predict the respiratory component within the TCG signal. A dual axis accelerometer that measures posture and levels of activity aids filtering movement artifact. With the addition of a single lead ECG, ensemble averaging is used to smooth artifact in the signal, and CO may be obtained by including a heart rate measure. Additional measures can be derived including left ventricular systolic time intervals such as Pre-ejection period, Peak ejection rate and time to peak ejection rate. The results show that increases and decreases in SV and CO can be measured over time. PMID:15133982

  18. [Mechanisms of changes in cardiac output during stimulation of afferent fibers of a somatic nerve].

    PubMed

    Osadchi?, L I; Balueva, T V; Sergeev, I V

    1985-06-01

    In anesthetized cats, the technique of electromagnetic expenditure-metry aided to study changes of the cardiac output and venous inflow in pressor responses to stimulation of the tibial nerve's afferent fibers. The cardiac output was found to increase in 47% of observations which was accompanied by increased venous inflow in half of the cases and by decreased one in 1/3 of observations. Vagotomy as well as suppression of the efferent link of cardiac responses with atropin and obsidan induced shifts of the cardiac output in the somatic nerve stimulation. The optimum level of arterial pressure responses was revealed peculiar by positive shifts of the cardiac output in pressor responses to the above action. PMID:2993045

  19. In vitro evaluation of an ultrasonic cardiac output monitoring (USCOM) device.

    PubMed

    Gregory, Shaun D; Cooney, Helena; Diab, Sara; Anstey, Chris; Thom, Ogilvie; Fraser, John F

    2016-02-01

    Non-invasive cardiac output monitoring techniques provide high yield, low risk mechanisms to identify and individually treat shock in the emergency setting. The non-invasive ultrasonic cardiac output monitoring (USCOM) device uses an ultrasound probe applied externally to the chest; however limitations exist with previous validation strategies. This study presents the in vitro validation of the USCOM device against calibrated flow sensors and compares user variability in simulated healthy and septic conditions. A validated mock circulation loop was used to simulate each condition with a range of cardiac outputs (2-10 l/min) and heart rates (50-95 bpm). Three users with varying degrees of experience using the USCOM device measured cardiac output and heart rate by placing the ultrasound probe on the mock aorta. Users were blinded to the condition, heart rate and cardiac output which were randomly generated. Results were reported as linear regression slope (β). All users estimated heart rate in both conditions with reasonable accuracy (β = 0.86-1.01), while cardiac output in the sepsis condition was estimated with great precision (β = 1.03-1.04). Users generally overestimated the cardiac output in the healthy simulation (β = 1.07-1.26) and reported greater difficulty estimating reduced cardiac output compared with higher values. Although there was some variability between users, particularly in the healthy condition (P < 0.01), all estimations were within a clinically acceptable range. In this study the USCOM provided a suitable measurement of cardiac output and heart rate when compared with our in vitro system. It is a promising technique to assist with the identification and treatment of shock. PMID:25749977

  20. Initial Observations of the Effects of Calcium Chloride Infusions in Pediatric Patients with Low Cardiac Output.

    PubMed

    Averin, Konstantin; Villa, Chet; Krawczeski, Catherine D; Pratt, Jesse; King, Eileen; Jefferies, John L; Nelson, David P; Cooper, David S; Ryan, Thomas D; Sawyer, Jaclyn; Towbin, Jeffrey A; Lorts, Angela

    2016-03-01

    Myocardial contractility and relaxation are highly dependent on calcium homeostasis. Immature myocardium, as in pediatric patients, is thought to be more dependent on extracellular calcium for optimal function. For this reason, intravenous calcium chloride infusions may improve myocardial function in the pediatric patient. The objectives of this study were to report the hemodynamic changes seen after administration of continuous calcium chloride to critically ill children. We retrospectively identified pediatric patients (newborn to 17 years old) with hemodynamic instability admitted to the cardiac ICU between May 2011 and May 2012 who received a continuous infusion of calcium chloride. The primary outcome was improvement in cardiac output, assessed by arterial-mixed venous oxygen saturation (A-V) difference. Sixty-eight patients, mean age 0.87 ± 2.67 years, received a total of 116 calcium infusions. Calcium chloride infusions resulted in significant improvements in primary and secondary measures of cardiac output at 2 and 6 h. Six hours after calcium initiation, A-V oxygen saturation difference decreased by 7.4 % (32.6 ± 2.1 to 25.2 ± 2.0 %, p < 0.001), rSO2 increased by 5.5 % (63.1 vs 68.6 %, p < 0.001), and serum lactate decreased by 0.9 mmol/l (3.3 vs 2.4 mmol/l, p < 0.001) with no change in HR (149.1 vs 145.6 bpm p = 0.07). Urine output increased 0.66 ml/kg/h in the 8-h period after calcium initiation when compared to pre-initiation (p = 0.003). Neonates had the strongest evidence of effectiveness with other age groups trending toward significance. Calcium chloride infusions improve markers of cardiac output in a heterogenous group of pediatric patients in a cardiac ICU. Neonates appear to derive the most benefit from utilization of these infusions. PMID:26687150

  1. Shoshin Beriberi With Low Cardiac Output and Hemodynamic Deterioration Treated Dramatically by Thiamine Administration.

    PubMed

    Imamura, Teruhiko; Kinugawa, Koichiro

    2015-01-01

    "Shoshin beriberi", which is a fulminant form of cardiovascular beriberi accompanied by hemodynamic deterioration with high cardiac output and decreased systemic blood pressure, caused by thiamine deficiency due to alcoholic abuse or malnutrition, is often difficult to address because of its rarity and non-specific symptoms. We here present a patient with a history of alcoholic abuse who had suffered hemodynamic deterioration with extremely low cardiac output refractory to extracorporeal membrane oxygenation and intravenous catecholamine support, which was improved dramatically by bolus intravenous thiamine administration. Such a type with low cardiac output would be the most severe form of Shoshin beriberi, and cannot be rescued without diagnostic administration of thiamine. PMID:26346515

  2. Use of the single-breath method of estimating cardiac output during exercise-stress testing.

    NASA Technical Reports Server (NTRS)

    Buderer, M. C.; Rummel, J. A.; Sawin, C. F.; Mauldin, D. G.

    1973-01-01

    The single-breath cardiac output measurement technique of Kim et al. (1966) has been modified for use in obtaining cardiac output measurements during exercise-stress tests on Apollo astronauts. The modifications involve the use of a respiratory mass spectrometer for data acquisition and a digital computer program for data analysis. The variation of the modified method for triplicate steady-state cardiac output measurements was plus or minus 1 liter/min. The combined physiological and methodological variation seen during a set of three exercise tests on a series of subjects was 1 to 2.5 liter/min. Comparison of the modified method with the direct Fick technique showed that although the single-breath values were consistently low, the scatter of data was small and the correlation between the two methods was high. Possible reasons for the low single-breath cardiac output values are discussed.

  3. Stormy Course of a Huge Submitral Aneurysm Causing Low Cardiac Output State

    PubMed Central

    Gokhroo, Rajendra Kumar; Kishor, Kamal; Ranwa, Bhanwar

    2016-01-01

    Submitral aneurysm is a rare structural abnormality of congenital or acquired aetiology. Most reported cases are from Africa. Unless promptly treated surgically this condition is invariably fatal. We report a case of a young Indian male who presented with dyspnea of recent onset, diagnosed to have a massive submitral aneurysm causing low cardiac output and compression of cardiac structures. PMID:27081448

  4. Quantification of the Impaired Cardiac Output Response to Exercise in Heart Failure: Application of a Non-Invasive Device

    PubMed Central

    Myers, Jonathan; Gujja, Pradeep; Neelagaru, Suresh; Hsu, Leon; Burkhoff, Daniel

    2009-01-01

    An impaired cardiac output (CO) response to exercise is a hallmark of chronic heart failure (CHF), and the degree to which CO is impaired is related to the severity of CHF and prognosis. However, practical methods for obtaining cardiac output during exercise are lacking, and what constitutes and impaired response is unclear. Forty six CHF patients and 13 normal subjects underwent cardiopulmonary exercise testing (CPX) while CO and other hemodynamic measurements at rest and during exercise were obtained using a novel, non-invasive, bioreactance device based on assessment of relative phase shifts of electric currents injected across the thorax, heart rate and ventricular ejection time. An abnormal cardiac output response to exercise was defined as achieving ≤ 95% of the confidence limits of the slope of the relationship between CO and oxygen uptake (VO2). An impaired CO slope identified patients with more severe CHF as evidenced by a lower peak VO2, lower peak CO, heightened VE/VCO2 slope, and lower oxygen uptake efficiency slope. CO can be estimated during exercise using a novel bioreactance technique; patients with an impaired response to exercise exhibit reduced exercise capacity and inefficient ventilation typical of more severe CHF. Non- invasive measurement of cardiac performance in response to exercise provides a simple method of identifying patients with more severe CHF and may complement the CPX in identifying CHF patients at high risk. Key points Non-invasive measurement of cardiac output during exercise is feasible in patients with heart failure. Impairment in the CO response to exercise identifies heart failure patients with more severe disease, lower exercise capacity and inefficient ventilation. Non-invasive measurement of cardiac performance during exercise has potentially important applications for the functional and prognostic assessment of patients with heart failure. PMID:24149996

  5. [The determination of cardiac output by the dilution of ultrasonic blood density].

    PubMed

    Eremenko, A A; Chaus, N I; Kislukhin, V V; Balykov, I V

    1998-01-01

    The authors propose assessing cardiac output (CO) by diluting the blood ultrasonic properties. For measuring CO, the peripheral artery and vein were connected with a catheter, and ultrasonic flowmetric pickup was attached to the shunt. Indicator (0.9% sodium chloride) was injected into the central vein. Changes in the blood ultrasonic characteristics during the indicator flow were recorded by ultrasonic flowmeter. Dilution curves were computer processed. The method was tried in 7 experimental dogs and clinically in 11 patients and compared with the thermodilution method. The coefficient of correlation was 0.98 in experiment and 0.97 in clinical trials. Dilution of ultrasonic density of the blood helps accurately assess the CO and is highly informative, which is confirmed by a strong correlation with the results of thermodilution. The method is simple, little invasive, realized using available equipment, the indicators are cheap and available, and repeated studies can be performed within short periods of time. PMID:9770808

  6. Lithium dilution measurement of cardiac output and arterial pulse waveform analysis: an indicator dilution calibrated beat-by-beat system for continuous estimation of cardiac output.

    PubMed

    Jonas, Max M; Tanser, Suzie J

    2002-06-01

    Lithium dilution cardiac output (LiDCO trade mark; LiDCO, London, UK) is a minimally invasive indicator dilution technique for the measurement of cardiac output. It was primarily developed as a simple calibration for the PulseCO trade mark (LiDCO, London, UK) continuous arterial waveform analysis monitor. The technique is quick and simple, requiring only an arterial line and central or peripheral venous access. These lines would probably already have been inserted in critical care patients. A small dose of lithium chloride is injected as an intravenous bolus, and cardiac output is derived from the dilution curve generated by a lithium-sensitive electrode attached to the arterial line. Studies in humans and animals have shown good agreement compared with results obtained with other techniques, and the efficacy of LiDCO trade mark in pediatric patients has also been proven. Compared with thermodilution, lithium dilution showed closer agreement in clinical studies with electromagnetic flow measurement.PulseCO trade mark is a beat-to-beat cardiac output monitor that calculates stroke volume from the arterial pressure waveform using an autocorrelation algorithm. The algorithm is not dependent on waveform morphology, but, rather, it calculates nominal stroke volume from a pressure-volume transform of the entire waveform. The nominal stroke volume is converted to actual stroke volume by calibration of the algorithm with LiDCO trade mark. Initial studies indicate good fidelity, and the results from centers in the United States and the United Kingdom are extremely encouraging. The PulseCO trade mark monitor incorporates software for interpretation of the hemodynamic data generated and provides a real-time analysis of arterial pressure variations (ie, stroke volume variation, pulse pressure variation, and systolic pressure variation) as theoretical guides to intravascular and cardiac filling. PMID:12386506

  7. Decrease of Total Antioxidative Capacity in Developed Low Cardiac Output Syndrome

    PubMed Central

    Kunt, Alper Sami; Andac, Mehmet Halit

    2012-01-01

    Background. It has been known that cardiac surgery induces an oxidative stress. The persistent oxidative stress during reperfusion may lead to depressed myocardial function resulting in low cardiac output syndrome (LCOS) necessitating inotropic or intra-aortic balloon counterpulsation support. Total antioxidant capacity (TAC) is a measurement of oxidative stress in tissues. The purpose of this study was to examine the TAC differences during coronary artery bypass graft (CABG) operation in patients who have developed LCOS and who have not. Material and Methods. Seventy-nine patients were enrolled in the study. Central venous blood samples were obtained immediately before surgery, during operation, and at the end of surgery to assess TAC. Clinical data regarding patient demographics and operative outcomes were prospectively collected and entered into our clinical database. Results. LCOS developed in 8 patients (10.12%). The TAC has decreased sharply in the LCOS patients compared with those who did not develop LCOS (P < 0.001) during operation. In addition, the receiver operating characteristic (ROC) area was 0.879. Conclusion. TAC has decreased during operation in a significant proportion of patients undergoing isolated CABG, and this is more prominent and serious and might be an independent variable in patients who have developed LCOS. This may be related to intraoperative misadventure or inadequate myocardial antioxidative protection. Routine measurement of the TAC during operation may provide information for assessment of the LCOS development. PMID:23251720

  8. Comparison of uncalibrated arterial waveform analysis in cardiac surgery patients with thermodilution cardiac output measurements

    PubMed Central

    Sander, Michael; Spies, Claudia D; Grubitzsch, Herko; Foer, Achim; Mller, Marcus; von Heymann, Christian

    2006-01-01

    Introduction Cardiac output (CO) monitoring is indicated only in selected patients. In cardiac surgical patients, perioperative haemodynamic management is often guided by CO measurement by pulmonary artery catheterisation (COPAC). Alternative strategies of CO determination have become increasingly accepted in clinical practice because the benefit of guiding therapy by data derived from the PAC remains to be proven and less invasive alternatives are available. Recently, a device offering uncalibrated CO measurement by arterial waveform analysis (COWave) was introduced. As far as this approach is concerned, however, the validity of the CO measurements obtained is utterly unclear. Therefore, the aim of this study was to compare the bias and the limits of agreement (LOAs) (two standard deviations) of COWave at four specified time points prior, during, and after coronary artery bypass graft (CABG) surgery with a simultaneous measurement of the gold standard COPAC and aortic transpulmonary thermodilution CO (COTranspulm). Methods Data from 30 patients were analysed during this prospective study. COPAC, COTranspulm, and COWave were determined in all patients at four different time points prior, during, and after CABG surgery. The COPAC and the COTranspulm were measured by triple injection of 10 ml of iced isotone sodium chloride solution into the central venous line of the PAC. Measurements of COWave were simultaneously taken at these time points. Results The overall correlation showed a Spearman correlation coefficient between COPAC and COWave of 0.53 (p < 0.01) and 0.84 (p < 0.01) for COPAC and COTranspulm. Bland-Altman analysis showed a mean bias and LOAs of 0.6 litres per minute and -2.2 to +3.4 litres per minute for COPAC versus COWave and -0.1 litres per minute and -1.8 to +1.6 litres per minute for COPAC versus COTranspulm. Conclusion Arterial waveform analysis with an uncalibrated algorithm COWave underestimated COPAC to a clinically relevant extent. The wide range of LOAs requires further evaluation. Better results might be achieved with an improved new algorithm. In contrast to this, we observed a better correlation of thermodilution COTranspulm and thermodilution COPAC measurements prior, during, and after CABG surgery. PMID:17118186

  9. Echocardiographic assessment of cardiac disease

    NASA Technical Reports Server (NTRS)

    Popp, R. L.

    1976-01-01

    The physical principles and current applications of echocardiography in assessment of heart diseases are reviewed. Technical considerations and unresolved points relative to the use of echocardiography in various disease states are stressed. The discussion covers normal mitral valve motion, mitral stenosis, aortic regurgitation, atrial masses, mitral valve prolapse, and idiopathic hypertrophic subaortic stenosis. Other topics concern tricuspic valve abnormalities, aortic valve disease, pulmonic valve, pericardial effusion, intraventricular septal motion, and left ventricular function. The application of echocardiography to congenital heart disease diagnosis is discussed along with promising ultrasonic imaging systems. The utility of echocardiography in quantitative evaluation of cardiac disease is demonstrated.

  10. Validation of a modified one-step rebreathing technique for measuring exercise cardiac output.

    PubMed

    Szlyk, P C; Evans, K C; Sils, I V

    1988-12-01

    A modification of the Farhi one-step rebreathing technique (1) is described for determining submaximal exercise cardiac output (Q). Factors critical in the estimation of Q are initial rebreathing bag volume and constant bag volume during the maneuver. By substituting a high flow rate analyzer (500 ml.min-1) for the recommended low flow rate mass spectrometer (60 ml.min-1), adding a recirculation circuit from the outlet of the analyzer to an inlet at the base of the rebreathing bag, and reducing the length of sample tubing to the analyzer, we were able to recirculate the subject's expired gas and achieve no loss of bag volume. No statistically significant differences in estimate of cardiac output were noted between the mass spectrometer and LB-2 analyzer with recirculation circuit during submaximal cycling. Heart rate and oxygen uptake were highly correlated with cardiac output and agreed well with the literature, irrespective of the CO2 analyzer system used. A unique feature of our method is that the subject's tidal volume is measured prior to the maneuver and then used as the initial rebreathing bag volume. Varying the bag volume by +/- 0.2 L from the tidal volume had no significant effect on the estimate of cardiac output during exercise. Now quick, reliable, and noninvasive measurements of cardiac output are feasible in subjects--not only in the laboratory but also in the field where a mass spectrometer is not readily portable. PMID:3149188

  11. Redistribution of cardiac output in response to heat exposure in the pony.

    PubMed

    McConaghy, F F; Hodgson, D R; Rose, R J; Hales, J R

    1996-07-01

    Radioactive microspheres were used to measure cardiac output and blood flow to most major tissues in 4 ponies at rest in thermoneutral (16 degrees C/60% RH) and mildly hot (41 degrees C/34% RH) environments. In response to heat stress there were increases in cardiac output (2-fold), respiratory frequency (5-fold), blood flow to the skin of the body (3-fold), and limbs (50%), respiratory muscles (2-fold) and the upper respiratory tract (3-fold). Ponies were able to maintain body temperature in the hot environment by increasing blood flow to the tissues involved in heat dissipation, while blood flow to all other tissues remained stable. This was achieved by increasing the cardiac output without need for reduction of blood flow to other tissues. PMID:8894549

  12. [The interrelations of arterial pressure, cardiac output and coronary blood flow during orthostatic reactions].

    PubMed

    Osadchiĭ, L I; Balueva, T V; Sergeev, I V

    1989-08-01

    The influence of hypotension induced with orthostasis, upon cardiac output and coronary flow was studied in anesthetized cats. The body tilt to 15-60 degrees lowered the mean arterial pressure parallel with reduction of cardiac output. Under the tilt up to 30 degrees and 60 degrees, a significant difference was found in decrease of systolic but not diastolic pressures. The degree of cardiac output reduction was two-fold greater than the degree of diastolic pressure reduction. The findings suggest a participation of vascular constrictor responses in the forming of orthostatic reactions. The coronary flow decrease only began with the tilt up to 30 degrees. Its extent did not depend on the intensity of hypotension being, probably, the result of the reduction of the heart work. PMID:2612665

  13. Validation of a new spectrometer for noninvasive measurement of cardiac output

    NASA Astrophysics Data System (ADS)

    Baum, Marc M.; Kumar, Sasi; Moss, John A.; Wagner, Peter D.

    2004-07-01

    Acetylene is a blood-soluble gas and for many years its uptake rate during rebreathing tests has been used to calculate the flow rate of blood through the lungs (normally equal to cardiac output) as well as the volume of lung tissue. A new, portable, noninvasive instrument for cardiac output determination using the acetylene uptake method is described. The analyzer relies on nondispersive IR absorption spectroscopy as its principle of operation and is configured for extractive (side-stream) sampling. The instrument affords exceptionally fast (30 ms, 10%-90%, 90%-10%, at 500 mL min-1 flow rates), interference-free, simultaneous measurement of acetylene, sulfur hexafluoride (an insoluble reference gas used in the cardiac output calculation), and carbon dioxide (to determine alveolar ventilation), with good (typically ±2% full-scale) signal-to-noise ratios. Comparison tests with a mass spectrometer using serially diluted calibration gas samples gave excellent (R2>0.99) correlation for all three gases, validating the IR system's linearity and accuracy. A similar level of agreement between the devices also was observed during human subject C2H2 uptake tests (at rest and under incremental levels of exercise), with the instruments sampling a common extracted gas stream. Cardiac output measurements by both instruments were statistically equivalent from rest to 90% of maximal oxygen consumption; the physiological validity of the measurements was confirmed by the expected linear relationship between cardiac output and oxygen consumption, with both the slope and intercept in the published range. These results indicate that the portable, low-cost, rugged prototype analyzer discussed here is suitable for measuring cardiac output noninvasively in a point-of-care setting.

  14. Continuous cardiac output measurement - Aspects of Doppler frequency analysis

    NASA Technical Reports Server (NTRS)

    Mackay, R. S.; Hechtman, H. B.

    1975-01-01

    From the suprasternal notch blood flow velocity in the aorta can be measured non-invasively by a Doppler probe. Integration over systole after frequency analysis gives a measure of stroke volume if a separate diameter observation is incorporated. Frequency analysis by a zero crossing counter or by a set of parallel phaselock loops was less effective than a set of bandpass filters. Observations on dogs, baboons and humans before and after exercise or surgery suggest the indications to be useful. Application to judging heart failure by the effect of introducing a volume load is indicated. Changes in output also are measured in freely moving subjects.

  15. Pulmonary arterial hypertension combined with a high cardiac output state: Three remarkable cases

    PubMed Central

    Spruijt, Onno A.; Bogaard, Harm-Jan; Vonk-Noordegraaf, Anton

    2013-01-01

    A congenital extrahepatic portosystemic venous shunt (CEPVS), also known as an Abernethy malformation, is a rare cause of pulmonary arterial hypertension (PAH). In this case series, we describe three male patients of 30, 23, and 27 years of age with PAH due to a CEPVS. In all three patients, a right heart catheterization revealed a high cardiac output. The aim of this case series is to make pulmonary hypertension physicians aware of the possibility of a CEPVS when PAH is accompanied with a high cardiac output state. PMID:24015348

  16. The ability of the Vigileo-FloTrac system to measure cardiac output and track cardiac output changes during one-lung ventilation.

    PubMed

    Suehiro, Koichi; Tanaka, Katsuaki; Yamada, Tokuhiro; Matsuura, Tadashi; Mori, Takashi; Funao, Tomoharu; Nishikawa, Kiyonobu

    2015-06-01

    This study was aimed at comparing the cardiac output (CO) measured by the Vigileo™-FloTrac™ system with that estimated by the thermodilution pulmonary artery catheter (PAC) during one-lung ventilation (OLV) and determining the reliability of this system in tracking phenylephrine-induced CO changes during OLV. Sixteen patients scheduled for descending aorta replacement were enrolled. The study was performed 30 min after starting OLV under stable hemodynamic conditions. We recorded hemodynamic variables, CO measured by PAC thermodilution (ICO), CO measured by Vigileo™-FloTrac™ system (Version 3.02, Edwards Lifesciences, Irvine, CA, USA) (APCO), and systemic vascular resistance index (SVRI) before (T0) and after (T1) phenylephrine (100 μg) administration. We used Bland-Altman analysis to compare ICO and APCO. Polar plot and four-quadrant plot were used to assess the tracking ability of the Vigileo™-FloTrac™ system against ICO after administration of phenylephrine. Ninety hemodynamic interventions were performed. Bland-Altman analysis revealed that the mean bias between APCO and ICO was 0.05 L/min and the percentage error, 46.9 %. Four-quadrant plot analysis showed a concordance rate of 24.7 %, while polar plot analysis showed that the concordance rate was 13.3 %; the angular bias, -45.9°; radial limit of agreement, 85.3°. The bias between APCO and ICO was significantly correlated with the SVRI value (p < 0.001, r(2) = 0.822). The reliability of the Vigileo™-FloTrac™ system during OLV to estimate CO and track phenylephrine-induced CO changes was not acceptable. PMID:25212705

  17. Noninvasive cardiac output and blood pressure monitoring cannot replace an invasive monitoring system in critically ill patients

    PubMed Central

    Stover, John F; Stocker, Reto; Lenherr, Renato; Neff, Thomas A; Cottini, Silvia R; Zoller, Bernhard; Béchir, Markus

    2009-01-01

    Background Monitoring of cardiac output and blood pressure are standard procedures in critical care medicine. Traditionally, invasive techniques like pulmonary artery catheter (PAC) and arterial catheters are widely used. Invasiveness bears many risks of deleterious complications. Therefore, a noninvasive reliable cardiac output (CO) and blood pressure monitoring system could improve the safety of cardiac monitoring. The aim of the present study was to compare a noninvasive versus a standard invasive cardiovascular monitoring system. Methods Nexfin HD is a continuous noninvasive blood pressure and cardiac output monitor system and is based on the development of the pulsatile unloading of the finger arterial walls using an inflatable finger cuff. During continuous BP measurement CO is calculated. We included 10 patients with standard invasive cardiac monitoring system (pulmonary artery catheter and arterial catheter) comparing invasively obtained data to the data collected noninvasively using the Nexfin HD. Results Correlation between mean arterial pressure measured with the standard arterial monitoring system and the Nexfin HD was r2 = 0.67 with a bias of -2 mmHg and two standard deviations of ± 16 mmHg. Correlation between CO derived from PAC and the Nexfin HD was r2 = 0.83 with a bias of 0.23 l/min and two standard deviations of ± 2.1 l/min; the percentage error was 29%. Conclusion Although the noninvasive CO measurement appears promising, the noninvasive blood pressure assessment is clearly less reliable than the invasively measured blood pressure. Therefore, according to the present data application of the Nexfin HD monitoring system in the ICU cannot be recommended generally. Whether such a tool might be reliable in certain critically ill patients remains to be determined. PMID:19821993

  18. Exercise cardiac output following Skylab missions - The second manned Skylab mission

    NASA Technical Reports Server (NTRS)

    Buderer, M. C.; Mauldin, D. G.; Rummel, J. A.; Michel, E. L.; Sawin, C. F.

    1976-01-01

    Cardiac output was measured during preflight and postflight exercise-stress tests on the Skylab astronauts. In the postflight tests immediately following the 28-, 59-, and 84-d earth orbital missions, the astronauts exhibited an approximate 30% decrease in cardiac output coupled with an approximate 50% decrease in cardiac stroke volume during exercise. These changes were accompanied by elevated heart rates and significant increases in total systemic peripheral vascular resistance. Mean arterial pressure was unchanged. All parameters returned to normal preflight values within 30 d of the end of the orbital period. Duration of the zero-G exposure did not appear to influence either the magnitude of the hemodynamic changes or the time-course of their return to normal. These results are discussed in relation to other cardiovascular findings and possible mechanisms responsible for the observations are outlined.

  19. Drug detection in breath: effects of pulmonary blood flow and cardiac output on propofol exhalation.

    PubMed

    Kamysek, Svend; Fuchs, Patricia; Schwoebel, Henny; Roesner, Jan P; Kischkel, Sabine; Wolter, Kathi; Loeseken, Christian; Schubert, Jochen K; Miekisch, Wolfram

    2011-10-01

    Breath analysis could offer a non-invasive means of intravenous drug monitoring if robust correlations between drug concentrations in breath and blood can be established. In this study, propofol blood and breath concentrations were determined in an animal model under varying physiological conditions. Propofol concentrations in breath were determined by means of two independently calibrated analytical methods: continuous, real-time proton transfer reaction mass spectrometry (PTR-MS) and discontinuous solid-phase micro-extraction coupled with gas chromatography mass spectrometry (SPME-GC-MS). Blood concentrations were determined by means of SPME-GC-MS. Effects of changes in pulmonary blood flow resulting in a decreased cardiac output (CO) and effects of dobutamine administration resulting in an increased CO on propofol breath concentrations and on the correlation between propofol blood and breath concentrations were investigated in seven acutely instrumented pigs. Discontinuous propofol determination in breath by means of alveolar sampling and SPME-GC-MS showed good agreement (R(2)=0.959) with continuous alveolar real-time measurement by means of PTR-MS. In all investigated animals, increasing cardiac output led to a deterioration of the relationship between breath and blood propofol concentrations (R(2)=0.783 for gas chromatography-mass spectrometry and R(2)=0.795 for PTR-MS). Decreasing pulmonary blood flow and cardiac output through banding of the pulmonary artery did not significantly affect the relationship between propofol breath and blood concentrations (R(2)>0.90). Estimation of propofol blood concentrations from exhaled alveolar concentrations seems possible by means of different analytical methods even when cardiac output is decreased. Increases in cardiac output preclude prediction of blood propofol concentration from exhaled concentrations. PMID:21643859

  20. Quantification of mitral regurgitation by automated cardiac output measurement: experimental and clinical validation

    NASA Technical Reports Server (NTRS)

    Sun, J. P.; Yang, X. S.; Qin, J. X.; Greenberg, N. L.; Zhou, J.; Vazquez, C. J.; Griffin, B. P.; Stewart, W. J.; Thomas, J. D.

    1998-01-01

    OBJECTIVES: To develop and validate an automated noninvasive method to quantify mitral regurgitation. BACKGROUND: Automated cardiac output measurement (ACM), which integrates digital color Doppler velocities in space and in time, has been validated for the left ventricular (LV) outflow tract but has not been tested for the LV inflow tract or to assess mitral regurgitation (MR). METHODS: First, to validate ACM against a gold standard (ultrasonic flow meter), 8 dogs were studied at 40 different stages of cardiac output (CO). Second, to compare ACM to the LV outflow (ACMa) and inflow (ACMm) tracts, 50 normal volunteers without MR or aortic regurgitation (44+/-5 years, 31 male) were studied. Third, to compare ACM with the standard pulsed Doppler-two-dimensional echocardiographic (PD-2D) method for quantification of MR, 51 patients (61+/-14 years, 30 male) with MR were studied. RESULTS: In the canine studies, CO by ACM (1.32+/-0.3 liter/min, y) and flow meter (1.35+/-0.3 liter/min, x) showed good correlation (r=0.95, y=0.89x+0.11) and agreement (deltaCO(y-x)=0.03+/-0.08 [mean+/-SD] liter/min). In the normal subjects, CO measured by ACMm agreed with CO by ACMa (r=0.90, p < 0.0001, deltaCO=-0.09+/-0.42 liter/min), PD (r=0.87, p < 0.0001, deltaCO=0.12+/-0.49 liter/min) and 2D (r=0.84, p < 0.0001, deltaCO=-0.16+/-0.48 liter/min). In the patients, mitral regurgitant volume (MRV) by ACMm-ACMa agreed with PD-2D (r= 0.88, y=0.88x+6.6, p < 0.0001, deltaMRV=2.68+/-9.7 ml). CONCLUSIONS: We determined that ACM is a feasible new method for quantifying LV outflow and inflow volume to measure MRV and that ACM automatically performs calculations that are equivalent to more time-consuming Doppler and 2D measurements. Additionally, ACM should improve MR quantification in routine clinical practice.

  1. Continuous minimally invasive peri-operative monitoring of cardiac output by pulmonary capnotracking: comparison with thermodilution and transesophageal echocardiography.

    PubMed

    Peyton, Philip J

    2012-04-01

    A number of technologies are available for minimally-invasive cardiac output measurement in patients during surgery but remain little used. A system has been developed based on CO(2) elimination (VCO(2)) by the lungs for use in ventilated patients, which can be fully integrated into a modern anesthesia/monitoring platform, and provides semi-automated, continuous breath-by-breath cardiac output monitoring. A prototype measurement system was constructed to measure VCO(2) and end-tidal CO(2) concentration with each breath. A baseline measurement of non-shunt cardiac output was made during a brief change in ventilator rate, according to the differential CO(2) Fick approach. Continuous breath-by-breath monitoring of cardiac output was then performed from measurement of VCO(2), using a derivation of the Fick equation applied to pulmonary CO(2) elimination. Automated recalibration was done periodically and data was processed and cardiac output displayed in real time. Measurements were compared with simultaneous measurements by bolus thermodilution in 77 patients undergoing cardiac surgery or liver transplantation. Overall mean bias [sd] for agreement in cardiac output measurement was -0.1 [1.2] L/min, percentage error +44.2%, r = 0.92. Concordance in measurement of changes of at least 15% in cardiac output was 80%. The method followed sudden changes in cardiac output due to arrythmias and run onto cardiopulmonary bypass in real time. The accuracy and precision were comparable to other clinical techniques. The method is relatively seamless and largely automated and has potential for continuous, cardiac output monitoring in ventilated patients during anesthesia and critical care. PMID:22350312

  2. Peripartum cardiomyopathy: postpartum decompensation and use of non-invasive cardiac output monitoring.

    PubMed

    Lorello, G; Cubillos, J; McDonald, M; Balki, M

    2014-02-01

    The utility of a non-invasive cardiac output monitor (NICOM™) in guiding the peripartum management and identification of postpartum complications in a patient with severe peripartum cardiomyopathy is reported. A 31-year-old nulliparous woman at 35 weeks of gestation presented with a three-week history of worsening dyspnea and progressive functional deterioration. A transthoracic echocardiogram showed severe left ventricular systolic dysfunction with an ejection fraction <20%. Cardiac status was monitored using NICOM™ during labor and delivery. The baseline values were: cardiac output 5.3 L/min, total peripheral resistance 1549 dynes.sec/cm(5), stroke volume 42.1 mL and stroke volume variation 18%. She received early epidural analgesia during labor, titrated slowly with a loading dose of 0.0625% bupivacaine 10 mL and fentanyl 25 μg, followed by patient-controlled epidural analgesia (0.0625% bupivacaine with fentanyl 2 μg/mL, infusion at 10 mL/h, bolus dose 5 mL and lockout interval 10 min). After epidural drug administration, total peripheral resistance decreased, cardiac output increased, and satisfactory analgesia was obtained. She had an uneventful vaginal delivery with a forceps-assisted second stage after prophylactic administration of furosemide 20 mg. NICOM™ was discontinued after delivery. Fifteen hours post-delivery, the patient developed cardiogenic shock, which resolved after aggressive therapy with inotropes and furosemide. NICOM™ can be used to guide treatment during labor and delivery in patients with critical peripartum cardiomyopathy. We suggest that use of NICOM™ be extended into the postpartum period to detect signs of cardiac decompensation in such patients. PMID:24360329

  3. Cardiac output and tissue blood flow in the abalone, Haliotis cracherodii (Mollusca, Gastropoda).

    PubMed

    Jorgensen, D D; Ware, S K; Redmond, J R

    1984-09-01

    Little is known about the characteristics of hemolymph (blood) flow in animals with open circulatory systems. We measured cardiac output and blood flow to specific tissues in the black abalone, Haliotis cracherodii, a gastropod mollusk. The use of thermodilution allowed us to make repeated measurements of cardiac output and cardiac stroke volume over relatively short time intervals (5-10 heart beats) in resting, unrestrained abalone while disturbing the animals minimally. Anatomical studies of the abalone circulation showed that the arterial system terminated in small diameter (approaching 10-20 micron in some cases) lacunar tissue spaces. Because of this, we used radioactive microspheres (which must be trapped in the tissue vasculature) to measure blood flow rates to selected tissues. The major findings of our study were that 1) cardiac output in the black abalone ranged from about 100 to 150 ml X kg-1 X min-1, and was highly correlated with body size; 2) weight-specific cardiac stroke volume was about 5 ml X kg-1, considerably larger than that of a mammal; 3) tissue blood flow rates ranged from 10 ml X 100 g-1 X min-1 (foot muscle) to 80 ml X 100 g-1 X min-1 (nephridial tissue), similar to typical tissue blood flow rates in mammals. Our data suggest that the blood in the abalone is directed to the tissues not in proportion to percent total body weight the tissues represent (as might be expected in an open vascular system), but apparently in proportion to tissue metabolic rate. PMID:6502086

  4. Postnatal changes in cardiac output and haemorrheology in normal neonates born at full term.

    PubMed Central

    Mandelbaum, V H; Alverson, D C; Kirchgessner, A; Linderkamp, O

    1991-01-01

    Circulatory adaptation was studied serially in 11 healthy term neonates on days 1, 3, and 5 by cross sectional and pulsed Doppler echocardiography. Changes in the determinants of blood viscosity (packed cell volume, plasma viscosity, red cell aggregation, and red cell deformability) were studied on day 1 and day 5. There was a 27% increase in the cardiac output as a result of increasing stroke volume, whereas heart rate did not change significantly. Mean blood pressure increased by nearly the same extent as cardiac output (21%), so that the overall resistance remained unchanged. Packed cell volume, red cell aggregation, and red cell deformability did not change significantly during the first five postnatal days. Plasma viscosity rose significantly (by 12%) so that whole blood viscosity increased during that period. As there was no change in overall systemic vascular resistance the vascular hindrance--calculated as the ratio of resistance: blood viscosity--decreased, thereby indicating vasodilation. PMID:2025030

  5. Levosimendan in a neonate with severe coarctation of aorta and low cardiac output syndrome.

    PubMed

    Boegli, Yann Olivier; Gioanni, Simone; van Steenberghe, Mathieu; Pouard, Philippe

    2013-01-01

    We report successful use of levosimendan after failed balloon angioplasty in a critically ill neonate with coarctation of aorta (CoA) and severe low cardiac output syndrome (LCOS). Treatment with levosimendan improved left heart function, and decreased lactate and brain natriuretic peptide levels. To our knowledge, this is the first report on the safe and successful use of levosimendan in the management of LCOS due to severe CoA in a neonate awaiting surgical repair. PMID:23816677

  6. Validation and application of single breath cardiac output determinations in man

    NASA Technical Reports Server (NTRS)

    Loeppky, J. A.; Fletcher, E. R.; Myhre, L. G.; Luft, U. C.

    1986-01-01

    The results of a procedure for estimating cardiac output by a single-breath technique (Qsb), obtained in healthy males during supine rest and during exercise on a bicycle ergometer, were compared with the results on cardiac output obtained by the direct Fick method (QF). The single breath maneuver consisted of a slow exhalation to near residual volume following an inspiration somewhat deeper than normal. The Qsb calculations incorporated an equation of the CO2 dissociation curve and a 'moving spline' sequential curve-fitting technique to calculate the instantaneous R from points on the original expirogram. The resulting linear regression equation indicated a 24-percent underestimation of QF by the Qsb technique. After applying a correction, the Qsb-QF relationship was improved. A subsequent study during upright rest and exercise to 80 percent of VO2(max) in 6 subjects indicated a close linear relationship between Qsb and VO2 for all 95 values obtained, with slope and intercept close to those in published studies in which invasive cardiac output measurements were used.

  7. Validation of a new method to measure cardiac output during extracorporeal detoxification.

    PubMed

    Nikiforov, Y V; Kisluchine, V V; Chaus, N I

    1996-01-01

    Cardiac output was measured in 11 patients during extra-corporeal detoxification after open heart surgery. All patients were mechanically ventilated and had pulmonary artery catheters for cardiac output (COT) measured by thermodilution. A sensor on the arterial side of the extracorporeal circulation measured flow and sound velocity transients. Injections of 2-5 ml 0.9% saline at 37 degrees C into the arterial line upstream of the sensor permitted its calibration; 10-20 ml of the same solution was injected intravenously or into the venous dialysis injection port, and cardiac output (COUD) was calculated by the ultrasound velocity dilution technique. COT was measured within 5 min of the ultrasound dilution measurement. CO was in the range of 2-8 L/m. The regression equation was COUD = 1.09 x COT-0.32 (r = 0.97, n = 31). These data suggest agreement between the ultrasound dilution technique and thermodilution. Ultrasound dilution is preferable in patients undergoing extracorporeal detoxification when pulmonary artery catheterization is not required or dangerous. PMID:8945017

  8. Cardiac Output and Performance during a Marathon Race in Middle-Aged Recreational Runners

    PubMed Central

    Billat, Véronique L.; Petot, Hélène; Landrain, Morgan; Meilland, Renaud; Koralsztein, Jean Pierre; Mille-Hamard, Laurence

    2012-01-01

    Purpose. Despite the increasing popularity of marathon running, there are no data on the responses of stroke volume (SV) and cardiac output (CO) to exercise in this context. We sought to establish whether marathon performance is associated with the ability to sustain high fractional use of maximal SV and CO (i.e, cardiac endurance) and/or CO, per meter (i.e., cardiac cost). Methods. We measured the SV, heart rate (HR), CO, and running speed of 14 recreational runners in an incremental, maximal laboratory test and then during a real marathon race (mean performance: 3 hr 30 min ± 45 min). Results. Our data revealed that HR, SV and CO were all in a high but submaximal steady state during the marathon (87.0 ± 1.6%, 77.2 ± 2.6%, and 68.7 ± 2.8% of maximal values, respectively). Marathon performance was inversely correlated with an upward drift in the CO/speed ratio (mL of CO × m−1) (r = −0.65, P < 0.01) and positively correlated with the runner's ability to complete the race at a high percentage of the speed at maximal SV (r = 0.83, P < 0.0002). Conclusion. Our results showed that marathon performance is inversely correlated with cardiac cost and positively correlated with cardiac endurance. The CO response could be a benchmark for race performance in recreational marathon runners. PMID:22645458

  9. The effects of long-term aerobic exercise on cardiac structure, stroke volume of the left ventricle, and cardiac output.

    PubMed

    Lee, Bo-Ae; Oh, Deuk-Ja

    2016-02-01

    The purpose of this study is to investigate the effect of the long-term aerobic exercises on cardiac structure, left ventricular stroke volume, and cardiac output. To achieve the purpose of the study, a total of 22 volunteers-including 10 people who have continued regular exercises and 12 people as the control group-were selected as subjects. With regard to data processing, the IBM SPSS Statistics ver. 21.0 was used to calculate the mean and standard deviation, and the difference of the means between the groups was verified through an independent t-test. As a result, there were significant differences between groups in the left ventricular end-diastolic internal dimension, left ventricular end-systolic internal dimension, left ventricular end-diastolic septum thickness. There were significant differences between groups in left ventricular end-diastolic volume, left ventricular mass, and left ventricular mass index per body surface area. However, in cardiac function, only left ventricular stroke volume showed a significant difference between groups. PMID:26933658

  10. The effects of long-term aerobic exercise on cardiac structure, stroke volume of the left ventricle, and cardiac output

    PubMed Central

    Lee, Bo-Ae; Oh, Deuk-Ja

    2016-01-01

    The purpose of this study is to investigate the effect of the long-term aerobic exercises on cardiac structure, left ventricular stroke volume, and cardiac output. To achieve the purpose of the study, a total of 22 volunteers—including 10 people who have continued regular exercises and 12 people as the control group—were selected as subjects. With regard to data processing, the IBM SPSS Statistics ver. 21.0 was used to calculate the mean and standard deviation, and the difference of the means between the groups was verified through an independent t-test. As a result, there were significant differences between groups in the left ventricular end-diastolic internal dimension, left ventricular end-systolic internal dimension, left ventricular end-diastolic septum thickness. There were significant differences between groups in left ventricular end-diastolic volume, left ventricular mass, and left ventricular mass index per body surface area. However, in cardiac function, only left ventricular stroke volume showed a significant difference between groups. PMID:26933658

  11. Measurement of cardiac output by automated single-breath technique, and comparison with thermodilution and Fick methods in patients with cardiac disease.

    PubMed

    Zenger, M R; Brenner, M; Haruno, M; Mahon, D; Wilson, A F

    1993-01-01

    Accurate noninvasive methods are needed for determination of cardiac output. Current methods are generally complex or may be unreliable. A previously described method, based on absorption of acetylene gas during a constant exhalation that enables calculation of cardiac output by estimating pulmonary capillary circulation, is incorporated in a new, automated commercial product (SensorMedics 2200). In this study, cardiac output by single-breath acetylene blood flow measured with this device was compared with the standard thermodilution and direct Fick methods in 20 patients undergoing cardiac or pulmonary artery catheterization. Patients inhaled test gas mixture to total lung capacity and exhaled at a constant rate through an adjustable resistor. Lung volumes and noninvasive acetylene blood flow value were calculated automatically. Correlation between the automated single-breath technique and both thermodilution and Fick cardiac output determinations was very high (correlation coefficients were 0.90 and 0.92, respectively), regression slopes were close to identity (0.98 and 0.90), and bias (-0.39 and -0.79 liter/min) and precision (0.94 and 1.02) were good; when shunt correction was applied, bias was reduced to 0.06 and 0.35 liter/min, respectively. Rapid, accurate, noninvasive measurement of cardiac output was easily obtained using the automated device. This technique may have a wide applicability for noninvasive evaluation of patients with cardiac disease and for monitoring effects of therapeutic interventions. PMID:8420224

  12. Caveolae protect endothelial cells from membrane rupture during increased cardiac output

    PubMed Central

    Cheng, Jade P.X.; Mendoza-Topaz, Carolina; Howard, Gillian; Chadwick, Jessica; Shvets, Elena; Cowburn, Andrew S.; Dunmore, Benjamin J.; Crosby, Alexi; Morrell, Nicholas W.

    2015-01-01

    Caveolae are strikingly abundant in endothelial cells, yet the physiological functions of caveolae in endothelium and other tissues remain incompletely understood. Previous studies suggest a mechanoprotective role, but whether this is relevant under the mechanical forces experienced by endothelial cells in vivo is unclear. In this study we have sought to determine whether endothelial caveolae disassemble under increased hemodynamic forces, and whether caveolae help prevent acute rupture of the plasma membrane under these conditions. Experiments in cultured cells established biochemical assays for disassembly of caveolar protein complexes, and assays for acute loss of plasma membrane integrity. In vivo, we demonstrate that caveolae in endothelial cells of the lung and cardiac muscle disassemble in response to acute increases in cardiac output. Electron microscopy and two-photon imaging reveal that the plasma membrane of microvascular endothelial cells in caveolin 1−/− mice is much more susceptible to acute rupture when cardiac output is increased. These data imply that mechanoprotection through disassembly of caveolae is important for endothelial function in vivo. PMID:26459598

  13. The Prognostic Value of Peak Cardiac Power Output in Chinese Patients with Chronic Heart Failure

    PubMed Central

    Ma, Wenlin; Gong, Zhu; Ni, Yi; Zhang, Xiaoyu; Xu, Wenjun; Jiang, Jinfa; Che, Lin; Xu, Jiahong; Yan, Wenwen; Zhou, Lin; Li, Guanghe; Zhang, Qiping; Wang, Lemin

    2016-01-01

    Background Cardiopulmonary exercise testing has been widely used to risk stratify patients with chronic heart failure (CHF). Peak oxygen consumption (peakVO2) was regarded as a powerful predictor of survival, as it is a surrogate for peak cardiac output (CO), which by most is considered the “true” measure of heart failure. Therefore, it is reasonable to hypothesize that CO is an even stronger predictor than peak VO2. The present study is aimed to investigate the prognostic value of peak cardiac power output (peak CPO) in comparison with peakVO2 in Chinese patients with CHF. Methods Participants provided written informed consent to participate in this study. Totally 129 patients with CHF underwent symptom-limited cardiopulmonary exercise testing (CPET), with mean age 59.1±11.4 years, 87.6% male, 57.4% ischemic etiology, body mass index (BMI) 24.7±3.7 kg/m2 and LVEF 38±9%. CO was measured using an inert gas rebreathing method. The primary endpoints are cardiac deaths. Results Over median 33.7-month follow-up, 19 cardiac deaths were reported. Among peak VO2,VE/VCO2 slope and Peak CPO, their area under ROC were 0.64, 0.67, 0.68, respectively (Ρ<0.05).The optimal thresholds for predicting cardiac deaths were peak VO2≤13.4 ml.kg-1.min-1, and VE/VCO2 slope≥39.3 and peak CPO≤ 1.1 respectively by ROC analysis. Finally, in patients with a peak VO2≤13.4 ml.kg-1.min-1 those with peak CPO>1.1W had better survival than those with peak CPO ≤ 1.1W. However, by multivariate analysis adjusted for age, sex, BMI, resting heart rate, LVMI, LVEF, Peak CPO was not an independent predictor of cardiac deaths (P> 0.05). Conclusions Peak CPO was not a predictor of cardiac death in Chinese CHF patients. PMID:26808510

  14. High flow variant postural orthostatic tachycardia syndrome amplifies the cardiac output response to exercise in adolescents

    PubMed Central

    Pianosi, Paolo T.; Goodloe, Adele H.; Soma, David; Parker, Ken O.; Brands, Chad K.; Fischer, Philip R.

    2014-01-01

    Abstract Postural orthostatic tachycardia syndrome (POTS) is characterized by chronic fatigue and dizziness and affected individuals by definition have orthostatic intolerance and tachycardia. There is considerable overlap of symptoms in patients with POTS and chronic fatigue syndrome (CFS), prompting speculation that POTS is akin to a deconditioned state. We previously showed that adolescents with postural orthostatic tachycardia syndrome (POTS) have excessive heart rate (HR) during, and slower HR recovery after, exercise – hallmarks of deconditioning. We also noted exaggerated cardiac output during exercise which led us to hypothesize that tachycardia could be a manifestation of a high output state rather than a consequence of deconditioning. We audited records of adolescents presenting with long‐standing history of any mix of fatigue, dizziness, nausea, who underwent both head‐up tilt table test and maximal exercise testing with measurement of cardiac output at rest plus 2–3 levels of exercise, and determined the cardiac output () versus oxygen uptake () relationship. Subjects with chronic fatigue were diagnosed with POTS if their HR rose ≥40 beat·min−1 with head‐up tilt. Among 107 POTS patients the distribution of slopes for the , relationship was skewed toward higher slopes but showed two peaks with a split at ~7.0 L·min−1 per L·min−1, designated as normal (5.08 ± 1.17, N = 66) and hyperkinetic (8.99 ± 1.31, N = 41) subgroups. In contrast, cardiac output rose appropriately with in 141 patients with chronic fatigue but without POTS, exhibiting a normal distribution and an average slope of 6.10 ± 2.09 L·min−1 per L·min−1. Mean arterial blood pressure and pulse pressure from rest to exercise rose similarly in both groups. We conclude that 40% of POTS adolescents demonstrate a hyperkinetic circulation during exercise. We attribute this to failure of normal regional vasoconstriction during exercise, such that patients must increase flow through an inappropriately vasodilated systemic circulation to maintain perfusion pressure. PMID:25168872

  15. Comparison of cardiac output determined by different rebreathing methods at rest and at peak exercise.

    PubMed

    Jakovljevic, Djordje G; Nunan, David; Donovan, Gay; Hodges, Lynette D; Sandercock, Gavin R H; Brodie, David A

    2008-03-01

    Several rebreathing methods are available for cardiac output (Q (T)) measurement. The aims of this study were threefold: first, to compare values for resting Q (T) produced by the equilibrium-CO(2), exponential-CO(2) and inert gas-N(2)O rebreathing methods and, second, to evaluate the reproducibility of these three methods at rest. The third aim was to assess the agreement between estimates of peak exercise Q (T) derived from the exponential and inert gas rebreathing methods. A total of 18 healthy subjects visited the exercise laboratory on different days. Repeated measures of Q (T), measured in a seated position, were separated by a 5 min rest period. Twelve participants performed an incremental exercise test to determine peak oxygen consumption. Two more exercise tests were used to measure Q (T) at peak exercise using the exponential and inert gas rebreathing methods. The exponential method produced significantly higher estimates at rest (averaging 10.9 l min(-1)) compared with the equilibrium method (averaging 6.6 l min(-1)) and the inert gas rebreathing method (averaging 5.1 l min(-1); P < 0.01). All methods were highly reproducible with the exponential method having the largest coefficient of variation (5.3%). At peak exercise, there were non-significant differences between the exponential and inert gas rebreathing methods (P = 0.14). The limits of agreement were -0.49 to 0.79 l min(-1). Due to the ability to evaluate the degree of gas mixing and to estimate intra-pulmonary shunt, we believe that the inert gas rebreathing method has the potential to measure Q (T) more precisely than either of the CO(2) rebreathing methods used in this study. At peak exercise, the exponential and inert gas rebreathing methods both showed acceptable limits of agreement. PMID:18074146

  16. Bioreactance Is Not Interchangeable with Thermodilution for Measuring Cardiac Output during Adult Liver Transplantation

    PubMed Central

    Han, Sangbin; Lee, Jong Hwan; Kim, Gaabsoo; Ko, Justin Sangwook; Choi, Soo Joo; Kwon, Ji Hae; Heo, Burn Young; Gwak, Mi Sook

    2015-01-01

    Background Thermodilution technique using a pulmonary artery catheter is widely used for the assessment of cardiac output (CO) in patients undergoing liver transplantation. However, the unclearness of the risk-benefit ratio of this method has led to an interest in less invasive modalities. Thus, we evaluated whether noninvasive bioreactance CO monitoring is interchangeable with thermodilution technique. Methods Nineteen recipients undergoing adult-to-adult living donor liver transplantation were enrolled in this prospective observational study. COs were recorded automatically by the two devices and compared simultaneously at 3-minute intervals. The Bland–Altman plot was used to evaluate the agreement between bioreactance and thermodilution. Clinically acceptable agreement was defined as a percentage error of limits of agreement <30%. The four quadrant plot was used to evaluate concordance between bioreactance and thermodilution. Clinically acceptable concordance was defined as a concordance rate >92%. Results A total of 2640 datasets were collected. The mean CO difference between the two techniques was 0.9 l/min, and the 95% limits of agreement were -3.5 l/min and 5.4 l/min with a percentage error of 53.9%. The percentage errors in the dissection, anhepatic, and reperfusion phase were 50.6%, 56.1%, and 53.5%, respectively. The concordance rate between the two techniques was 54.8%. Conclusion Bioreactance and thermodilution failed to show acceptable interchangeability in terms of both estimating CO and tracking CO changes in patients undergoing liver transplantation. Thus, the use of bioreactance as an alternative CO monitoring to thermodilution, in spite of its noninvasiveness, would be hard to recommend in these surgical patients. PMID:26017364

  17. Omega-3 fatty acid supplementation enhances stroke volume and cardiac output during dynamic exercise.

    PubMed

    Walser, Buddy; Stebbins, Charles L

    2008-10-01

    Docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) have beneficial effects on cardiovascular function. We tested the hypotheses that dietary supplementation with DHA (2 g/day) + EPA (3 g/day) enhances increases in stroke volume (SV) and cardiac output (CO) and decreases in systemic vascular resistance (SVR) during dynamic exercise. Healthy subjects received DHA + EPA (eight men, four women) or safflower oil (six men, three women) for 6 weeks. Both groups performed 20 min of bicycle exercise (10 min each at a low and moderate work intensity) before and after DHA + EPA or safflower oil treatment. Mean arterial pressure (MAP), heart rate (HR), SV, CO, and SVR were assessed before exercise and during both workloads. HR was unaffected by DHA + EPA and MAP was reduced, but only at rest (88 +/- 5 vs. 83 +/- 4 mm Hg). DHA + EPA augmented increases in SV (14.1 +/- 6.3 vs. 32.3 +/- 8.7 ml) and CO (8.5 +/- 1.0 vs. 10.3 +/- 1.2 L/min) and tended to attenuate decreases in SVR (-7.0 +/- 0.6 vs. -10.1 +/- 1.6 mm Hg L(-1) min(-1)) during the moderate workload. Safflower oil treatment had no effects on MAP, HR, SV, CO or SVR at rest or during exercise. DHA + EPA-induced increases in SV and CO imply that dietary supplementation with these fatty acids can increase oxygen delivery during exercise, which may have beneficial clinical implications for individuals with cardiovascular disease and reduced exercise tolerance. PMID:18563435

  18. Non-invasive cardiac output monitoring for cesarean delivery under epidural anesthesia in a patient with Marfan syndrome and cardiomyopathy.

    PubMed

    Beaudry, S; Pick, J; Heerdt, P M

    2016-02-01

    Maternal cardiac output and stroke volume increase significantly at the time of cesarean delivery. Parturients with baseline myocardial dysfunction are at increased risk of cardiovascular decompensation in the peripartum period and close hemodynamic monitoring is warranted. We report our use of intraoperative non-invasive cardiac output monitoring during cesarean delivery under epidural anesthesia in a 24-year-old woman with dilated cardiomyopathy secondary to Marfan syndrome, aortic arch, aortic valve and mitral valve replacements and a left ventricular ejection fraction of 37%. Three distinct hemodynamic trends were noted. After achieving adequate surgical anesthesia with 2% lidocaine 20mL, cardiac output and stroke volume rose for approximately 20min from baseline values of 6.3L/min and 69mL, respectively, to 9L/min and 107mL. Values subsequently trended down and remained depressed for nearly 20min following delivery. The lack of immediate post-delivery increases in both cardiac output and stroke volume were attributed to acute blood loss, intravascular volume depletion from fluid restriction, and slow infusion of oxytocin. By the end of surgery, cardiac output and stroke volume ultimately increased by 66% and 84% of baseline values, respectively. Systemic blood pressure, heart rate and cardiac output did not appear to correlate despite the use of phenylephrine to manage hypotension. The patient remained hemodynamically stable with no evidence of acute volume overload. PMID:26718697

  19. Cardiac magnetic resonance assessment of takotsubo cardiomyopathy.

    PubMed

    Abbas, A; Sonnex, E; Pereira, R S; Coulden, R A

    2016-01-01

    Takotsubo cardiomyopathy is an important condition that can be difficult to differentiate from acute coronary syndrome on the basis of clinical, electrocardiogram, and cardiac enzyme assessment alone. Although coronary angiography remains important in the acute assessment of patients with suspected takotsubo cardiomyopathy, cardiac magnetic resonance (CMR) has emerged over the last decade as an important non-invasive imaging tool in the diagnosis and follow-up of this condition. We present a review highlighting the CMR features of takotsubo cardiomyopathy and its complications with particular focus on differentiating this condition from acute myocardial infarction and myocarditis. PMID:26607916

  20. HDL Mimetic Peptide Administration Improves Left Ventricular Filling and Cardiac output in Lipopolysaccharide-Treated Rats

    PubMed Central

    Datta, Geeta; Gupta, Himanshu; Zhang, Zhenghao; Mayakonda, Palgunachari; Anantharamaiah, G.M.; White, C. Roger

    2012-01-01

    Aims Cardiac dysfunction is a complication of sepsis and contributes to morbidity and mortality. Since raising plasma apolipoprotein (apo) A-I and high density lipoprotein (HDL) concentration reduces sepsis complications, we tested the hypothesis that the apoA-I mimetic peptide 4F confers similar protective effects in rats treated with lipopolysaccharide (LPS). Methods and results Male Sprague-Dawley (SD) rats were randomized to receive saline vehicle (n=13), LPS (10 mg/kg: n=16) or LPS plus 4F (10 mg/kg each: n=13) by intraperitoneal injection. Plasma cytokine and chemokine levels were significantly elevated 24 hrs after LPS administration. Echocardiographic studies revealed changes in cardiac dimensions that resulted in a reduction in left ventricular end-diastolic volume (LVEDV), stroke volume (SV) and cardiac output (CO) 24 hrs after LPS administration. 4F treatment reduced plasma levels of inflammatory mediators and increased LV filling, resulting in improved cardiac performance. Chromatographic separation of lipoproteins from plasma of vehicle, LPS and LPS+4F rats revealed similar profiles. Further analyses showed that LPS treatment reduced the agarose electrophoretic mobility of isolated HDL fractions. HDL-associated proteins were characterized by SDSPAGE and mass spectrometry. ApoA-I and apoA-IV were reduced while apoE content was increased in LPStreated rats. 4F treatment in vivo attenuated changes in HDL-associated apolipoproteins and increased the electrophoretic mobility of the particle. Conclusions The ability of 4F to reduce inflammation and improve cardiac performance in LPS-treated rats may be due to its capacity to neutralize endotoxin and prevent adverse changes in HDL composition and function. PMID:23227448

  1. Sensitivity of Outcome Assessment in Cardiac Rehabilitation.

    ERIC Educational Resources Information Center

    Denollet, Johan

    1993-01-01

    Differential sensitivity to change of three measures of men who participated in cardiac rehabilitation was measured to evaluate the hypothesis that measures that enhance subjective health and well-being are more appropriate to assess change than are measures of psychopathology. Rehabilitation subjects, but not control subjects, reported a decrease

  2. NOTE: Increasing cardiac output and decreasing oxygenation sequence in pump twins of acardiac twin pregnancies

    NASA Astrophysics Data System (ADS)

    van Gemert, Martin J. C.; Umur, Asli; van den Wijngaard, Jeroen P. H. M.; Van Bavel, Ed; Vandenbussche, Frank P. H. A.; Nikkels, Peter G. J.

    2005-02-01

    An acardiac twin pregnancy is a rare but serious complication of monochorionic twinning and consists of an acardiac twin and a pump twin. The acardiac twin is a severely malformed fetus that lacks most organs, particularly a heart, but grows during pregnancy because it is perfused by the developmentally normal pump twin via a set of arterioarterial and venovenous placental anastomoses. Pump twins die intrauterine or neonatally in about 50% of the cases. Because the effects of an acardiac mass on the pump twin's development are incompletely known, methods for outcome prognosis are currently not available. We sought to derive simple relations for the pump twin's excess cardiac output and decreased oxygenation and to use available clinical cases for a preliminary test of the model. As a method, we used a theoretical flow model to represent the fetoplacental circulation of an acardiac twin pregnancy and estimated blood deoxygenation and reoxygenation following perfusion of the two bodies and placentas, respectively. The results show the pump twin's excess cardiac output and decrease of venous oxygen saturation to depend on the ratio of pump twin to acardiac twin umbilical blood flow, whose ratio can be measured by ultrasonography. The clinical cases show a decreasing umbilical flow ratio with gestation. In conclusion, prospective serial study is necessary to test whether measurement of umbilical flow ratios allows monitoring the pump twin's pathophysiologic development, possibly resulting in a guideline for prognosis of pump twin survival.

  3. Cardiac output and vasodilation in the vasovagal response: An analysis of the classic papers.

    PubMed

    Wieling, Wouter; Jardine, David L; de Lange, Frederik J; Brignole, Michele; Nielsen, Henning B; Stewart, Julian; Sutton, Richard

    2016-03-01

    The simple faint is secondary to hypotension and bradycardia resulting in transient loss of consciousness. According to Ohm's law applied to the circulation, BP = SVR × CO, hypotension can result from a decrease in systemic vascular resistance (SVR), cardiac output (CO), or both. It is important to understand that when blood pressure (BP) is falling, SVR and CO do not change reciprocally as they do in the steady state. In 1932, Lewis, assuming that decreased SVR alone accounted for hypotension, defined "the vasovagal response" along pathophysiologic lines to denote the association of vasodilation with vagal-induced bradycardia in simple faint. Studies performed by Barcroft and Sharpey-Schafer between 1940 and 1950 used volume-based plethysmography to demonstrate major forearm vasodilation during extreme hypotension and concluded that the main mechanism for hypotension was vasodilation. Plethysmographic measurements were intermittent and not frequent enough to capture rapid changes in blood flow during progressive hypotension. However, later investigations by Weissler, Murray, and Stevens performed between 1950 and 1970 used invasive beat-to-beat BP measurements and more frequent measurements of CO using the Fick principle. They demonstrated that CO significantly fell before syncope, and little vasodilation occurred until very late in the vasovagal reaction Thus, since the 1970s, decreasing cardiac output rather than vasodilation has been regarded as the principal mechanism for the hypotension of vasovagal syncope. PMID:26598322

  4. Haemoglobin concentration and linear cardiac output, peripheral resistance, and oxygen transport.

    PubMed Central

    Daniel, M K; Bennett, B; Dawson, A A; Rawles, J M

    1986-01-01

    Increasing the haemoglobin concentration results in increased oxygen transport at the cost of increased blood viscosity. This suggested the concept of an optimum packed cell volume for maximising oxygen transport and a study was therefore conducted seeking supportive evidence. Linear cardiac output was measured as minute distance by Doppler ultrasound in 40 patients with haemopoietic disorders who had stable haemoglobin concentrations ranging from 30 to 200 g/l. The correlation between haemoglobin concentration and minute distance (r = -0.45; p less than 0.01) was negative, and correlations between haemoglobin concentration and mean blood pressure (r = 0.66; p less than 0.001) and haemoglobin concentration and peripheral resistance (r = 0.64; p less than 0.001) were positive. Calculated oxygen transport increased across the whole range of haemoglobin values. These results suggest that adjustment of peripheral resistance in response to oxygen availability overrides the influence of blood viscosity on cardiac output and that the optimum packed cell volume for oxygen transport is the highest that can be achieved. PMID:3083941

  5. The Neuromuscular Transform of the Lobster Cardiac System Explains the Opposing Effects of a Neuromodulator on Muscle Output

    PubMed Central

    Williams, Alex H.; Calkins, Andrew; O'Leary, Timothy; Symonds, Renee; Marder, Eve

    2013-01-01

    Motor neuron activity is transformed into muscle movement through a cascade of complex molecular and biomechanical events. This nonlinear mapping of neural inputs to motor behaviors is called the neuromuscular transform (NMT). We examined the NMT in the cardiac system of the lobster Homarus americanus by stimulating a cardiac motor nerve with rhythmic bursts of action potentials and measuring muscle movements in response to different stimulation patterns. The NMT was similar across preparations, which suggested that it could be used to predict muscle movement from spontaneous neural activity in the intact heart. We assessed this possibility across semi-intact heart preparations in two separate analyses. First, we performed a linear regression analysis across 122 preparations in physiological saline to predict muscle movements from neural activity. Under these conditions, the NMT was predictive of contraction duty cycle but was unable to predict contraction amplitude, likely as a result of uncontrolled interanimal variability. Second, we assessed the ability of the NMT to predict changes in motor output induced by the neuropeptide C-type allatostatin. Wiwatpanit et al. (2012) showed that bath application of C-type allatostatin produced either increases or decreases in the amplitude of the lobster heart contractions. We show that an important component of these preparation-dependent effects can arise from quantifiable differences in the basal state of each preparation and the nonlinear form of the NMT. These results illustrate how properly characterizing the relationships between neural activity and measurable physiological outputs can provide insight into seemingly idiosyncratic effects of neuromodulators across individuals. PMID:24133260

  6. Reference values for total blood volume and cardiac output in humans

    SciTech Connect

    Williams, L.R.

    1994-09-01

    Much research has been devoted to measurement of total blood volume (TBV) and cardiac output (CO) in humans but not enough effort has been devoted to collection and reduction of results for the purpose of deriving typical or {open_quotes}reference{close_quotes} values. Identification of normal values for TBV and CO is needed not only for clinical evaluations but also for the development of biokinetic models for ultra-short-lived radionuclides used in nuclear medicine (Leggett and Williams 1989). The purpose of this report is to offer reference values for TBV and CO, along with estimates of the associated uncertainties that arise from intra- and inter-subject variation, errors in measurement techniques, and other sources. Reference values are derived for basal supine CO and TBV in reference adult humans, and differences associated with age, sex, body size, body position, exercise, and other circumstances are discussed.

  7. Thermodilution and Fick cardiac outputs differ: Impact on pulmonary hypertension evaluation

    PubMed Central

    Fares, Wassim H; Blanchard, Sarah K; Stouffer, George A; Chang, Patricia P; Rosamond, Wayne D; Ford, Hubert James; Aris, Robert M

    2012-01-01

    BACKGROUND: The relationship between thermodilution and indirect Fick cardiac output determination methods has not been well described. OBJECTIVE: To describe the relationship between these two cardiac output determination methods in patients evaluated for pulmonary hypertension and to highlight potential clinical implications. METHODS: A retrospective review of charts of all adult patients who underwent a right heart catheterization (RHC) between January 1, 2007 and November 10, 2010, and participated in the pulmonary hypertension program of the pulmonary division at an academic institution was conducted. For validation, the charts of all patients who underwent RHC during the same period within the cardiology division were reviewed. RESULTS: A total of 198 patients underwent 213 RHCs, 79 (40%) of whom had pulmonary arterial hypertension, were included. Forty-three per cent of patients had >20% difference between thermodilution and Fick. The average difference (thermodilution − Fick ±SD) was −0.39±2.03 L/min (n=213; P=0.006). There was no significant difference in bias or variability between thermodilution and Fick among patients with tricuspid regurgitant jet velocity (TRJ) of <3 m/s versus those with TRJ >3 m/s (−0.41±2.10 L/min versus −0.36±1.93 L/min, respectively; P=0.87). In a multivariable analysis, the thermodilution-Fick difference increased with age (P=0.001). DISCUSSION: The presence of such discrepancy in 36% of patients evaluated for heart failure and/or heart transplant validated the results. In total, 37% of the 1315 procedures (213 performed by pulmonologists and 1102 performed by cardiologists) had a difference of >20% between thermodilution and Fick. CONCLUSION: Significant discrepancy exists between thermodilution and indirect Fick methods. This discrepancy potentially impacts pulmonary arterial hypertension prognostication and diagnosis, and is independent of TRJ. PMID:22891186

  8. Noninvasive aortic bloodflow by Pulsed Doppler Echocardiography (PDE) compared to cardiac output by the direct Fick procedure

    NASA Technical Reports Server (NTRS)

    1980-01-01

    Left ventricular stroke volume was estimated from the systolic velocity integral in the ascending aorta by pulsed Doppler Echocardiography (PDE) and the cross sectional area of the aorta estimated by M mode echocardiography on 15 patients with coronary disease undergoing right catheterization for diagnostic purposes. Cardiac output was calculated from stroke volume and heart volume using the PDE method as well as the Fick procedure for comparison. The mean value for the cardiac output via the PDE method (4.42 L/min) was only 6% lower than for the cardiac output obtained from the Fick procedure (4.69 L/min) and the correlation between the two methods was excellent (r=0.967, p less than .01). The good agreement between the two methods demonstrates that the PDE technique offers a reliable noninvasive alternative for estimating cardiac output, requiring no active cooperation by the subject. It was concluded that the Doppler method is superior to the Fick method in that it provides beat by beat information on cardiac performance.

  9. Thromboresistant surface coatings for the measurement of cardiac output through continuous low flow peripheral A-V shunts.

    PubMed

    Deeb, G M; Borovetz, H S; Griffith, B P; Hardesty, R L

    1980-01-01

    The dilution technique for determining cardiac output using indocyanine green dye is limited in patients weighing less than 20 kg because of the obligatory volume loss. Reproducible achieved using the green dye dilution method by the establishment of a low flow peripheral arteriovenous shunt. The shunt materials were treated with thromboresistant agents--TDMAC (7%) and albumin (1 g/dl)--to facilitate the use of this technique without heparin. For A-V shunt flow rates of 8-30 cc/min reproducible values of cardiac output were obtained for up to 38 hours which were in good agreement with determinations made using the conventional technique of dye dilution. PMID:6986120

  10. Design and assessment of cardiac SPECT systems

    NASA Astrophysics Data System (ADS)

    Lee, Chih-Jie

    Single-photon emission computed tomography (SPECT) is a modality widely used to detect myocardial ischemia and myocardial infarction. Objectively assessing and comparing different SPECT systems is important so that the best detectability of cardiac defects can be achieved. Whitaker, Clarkson, and Barrett's study on the scanning linear observer (SLO) shows that the SLO can be used to estimate the location and size of signals. One major advantage of the SLO is that it can be used with projection data rather than reconstruction data. Thus, this observer model assesses overall hardware performance independent by any reconstruction algorithm. In addition, we will show that the run time of image-quality studies is significantly reduced. Several systems derived from the GE CZT-based dedicated cardiac SPECT camera Discovery 530c design, which is officially named the Alcyone Technology: Discovery NM 530c, were assessed using the performance of the SLO for the task of detecting cardiac defects and estimating the properties of the defects. Clinically, hearts can be virtually segmented into three coronary artery territories: left anterior descending artery (LAD), left circumflex artery (LCX), and right coronary artery (RCA). One of the most important functions of a cardiac SPECT system is to produce images from which a radiologist can correctly predict in which territory the defect exists. A good estimation of the defect extent from the images is also very helpful for determining the seriousness of the myocardial ischemia. In this dissertation, both locations and extent of defects were estimated by the SLO, and system performance was assessed using localization receiver operating characteristic (LROC) / estimation receiver operating characteristic (EROC) curves. Area under LROC curve (AULC) / area under EROC curve (AUEC) and true positive fraction (TPF) at specific false positive fraction (FPF) can be treated as the gures of merit (FOMs). As the results will show, a combination of the SLO and LROC / EROC curves can determine the configuration that has the most estimation/detection information and thus is a useful method for assessing cardiac SPECT systems.

  11. Influence of water immersion, water gymnastics and swimming on cardiac output in patients with heart failure

    PubMed Central

    Schmid, Jean‐Paul; Noveanu, Markus; Morger, Cyrill; Gaillet, Raymond; Capoferri, Mauro; Anderegg, Matthias; Saner, Hugo

    2007-01-01

    Background Whole‐body water immersion leads to a significant shift of blood from the periphery to the intrathoracic circulation, followed by an increase in central venous pressure and heart volume. In patients with severely reduced left ventricular function, this hydrostatically induced volume shift might overstrain the cardiovascular adaptive mechanisms and lead to cardiac decompensation. Aim To assess the haemodynamic response to water immersion, gymnastics and swimming in patients with chronic heart failure (CHF). Methods 10 patients with compensated CHF (62.9 (6.3) years, ejection fraction 31.5% (4.1%), peak oxygen consumption (V̇o2) 19.4 (2.8) ml/kg/min), 10 patients with coronary artery disease (CAD) but preserved left ventricular function (57.2 (5.6) years, ejection fraction 63.9% (5.5%), peak V̇o2 28 (6.3) ml/kg/min), and 10 healthy controls (32.8 (7.2) years, peak V̇o2 45.6 (6) ml/kg/min) were examined. Haemodynamic response to thermoneutral (32°C) water immersion and exercise was measured using a non‐invasive foreign gas rebreathing method during stepwise water immersion, water gymnastics and swimming. Results Water immersion up to the chest increased cardiac index by 19% in controls, by 21% in patients with CAD and by 16% in patients with CHF. Although some patients with CHF showed a decrease of stroke volume during immersion, all subjects were able to increase cardiac index (by 87% in healthy subjects, by 77% in patients with CAD and by 53% in patients with CHF). V̇o2 during swimming was 9.7 (3.3) ml/kg/min in patients with CHF, 12.4 (3.5) ml/kg/min in patients with CAD and 13.9 (4) ml/kg/min in controls. Conclusions Patients with severely reduced left ventricular function but stable clinical conditions and a minimal peak V̇o2 of at least 15 ml/kg/min during a symptom‐limited exercise stress test tolerate water immersion and swimming in thermoneutral water well. Although cardiac index and V̇o2 are lower than in patients with CAD with preserved left ventricular function and controls, these patients are able to increase cardiac index adequately during water immersion and swimming. PMID:17164483

  12. Cardiac output method comparison studies: the relation of the precision of agreement and the precision of method.

    PubMed

    Hapfelmeier, Alexander; Cecconi, Maurizio; Saugel, Bernd

    2016-04-01

    Cardiac output (CO) plays a crucial role in the hemodynamic management of critically ill patients treated in the intensive care unit and in surgical patients undergoing major surgery. In the field of cardiovascular dynamics, innovative techniques for CO determination are increasingly available. Therefore, the number of studies comparing these techniques with a reference, such as pulmonary artery thermodilution, is rapidly growing. There are mainly two outcomes of such method comparison studies: (1) the accuracy of agreement and (2) the precision of agreement. The precision of agreement depends on the precision of each method, i.e., the precision that the studied and the reference technique are able to achieve. We call this "precision of method". A decomposition of variance shows that method agreement does not only depend on the precision of method but also on another important source of variability, i.e., the method's general variability about the true values. Ignorance of that fact leads to falsified conclusions about the precision of method of the studied technique. In CO studies, serial measurements are frequently confused with repeated measurements. But as the actual CO of a subject changes from assessment to assessment, there is no real repetition of a measurement. This situation equals a scenario in which single measurements are given for multiple true values per subject. In such a case it is not possible to assess the precision of method. PMID:26026648

  13. Pulmonary diffusing capacity, capillary blood volume, and cardiac output during sustained microgravity

    NASA Technical Reports Server (NTRS)

    Prisk, G. K.; Guy, Harold J. B.; Elliott, Ann R.; Deutschman, Robert A., III; West, John B.

    1993-01-01

    We measured pulmonary diffusing capacity (DL), diffusing capacity per unit lung volume, pulmonary capillary blood volume (Vc), membrane diffusing capacity (Dm), pulmonary capillary blood flow or cardiac output (Qc), and cardiac stroke volume (SV) in four subjects exposed to nine days of microgravity. DL in microgravity was elevated compared with preflight standing values and was higher than preflight supine because of the elevation of both Vc and Dm. The elevation in Vc was comparable to that measured supine in 1 G, but the increase in Dm was in sharp contrast to the supine value. We postulate that, in 0 G, pulmonary capillary blood is evenly distributed throughout the lung, providing for uniform capillary filling, leading to an increase in the surface area available for diffusion. By contrast, in the supine 1-G state, the capillaries are less evenly filled, and although a similar increase in blood volume is observed, the corresponding increase in surface area does not occur. DL and its subdivisions showed no adaptive changes from the first measurement 24 h after the start of 0 G to eight days later. Similarly, there were no trends in the postflight data, suggesting that the principal mechanism of these changes was gravitational. The increase in Dm suggests that subclinical pulmonary edema did not result from exposure to 0 G. Qc was modestly increased inflight and decreased postflight compared with preflight standing. Compared with preflight standing, SV was increased 46 percent inflight and decreased 14 percent in the 1st week postflight. There were temporal changes in Qc and SV during 0 G, with the highest values recorded at the first measurement, 24 h into the flight. The lowest values of Qc and SV occurred on the day of return.

  14. Efficacy of Goal-Directed Therapy Using Bioreactance Cardiac Output Monitoring after Valvular Heart Surgery

    PubMed Central

    Lee, Sak; Lee, Seung Hyun; Chang, Byung-Chul

    2015-01-01

    Purpose We compared the efficacy of postoperative hemodynamic goal-directed therapy (GDT) using a pulmonary artery catheter (PAC) and bioreactance-based noninvasive cardiac output monitoring (NICOM) in patients with atrial fibrillation undergoing valvular heart surgery. Materials and Methods Fifty eight patients were randomized into two groups of GDT with common goals to maintain a mean arterial pressure of 60-80 mm Hg and cardiac index ?2 L/min/m2: the PAC group (n=29), based on pulmonary capillary wedge pressure, and the NICOM group (n=29), based on changes in stroke volume index after passive leg raising. The primary efficacy variable was length of hospital stay. Secondary efficacy variables included resource utilization including vasopressor and inotropic requirement, fluid balance, and major morbidity endpoints. Results Patient characteristics and operative data were similar between the groups, except that significantly more patients underwent double valve replacement in the NICOM group. The lengths of hospital stay were not different between the two groups (12.24.8 days vs. 10.84.0 days, p=0.239). Numbers of patients requiring epinephrine (5 vs. 0, p=0.019) and ventilator care >24 h (6 vs. 1, p=0.044) were significantly higher in the PAC group. The PAC group also required significantly larger amounts of colloid (1652519 mL vs. 11430463 mL, p=0.004). Conclusion NICOM-based postoperative hemodynamic GDT showed promising results in patients with atrial fibrillation undergoing valvular heart surgery in terms of resource utilization. PMID:26069111

  15. Cardiac MR assessment of microvascular obstruction

    PubMed Central

    Matthews, G H; Brown, I W; Shambrook, J S; Peebles, C R; Harden, S P

    2015-01-01

    Microvascular obstruction (MVO) is usually seen in a proportion of patients with acute myocardial infarction following reperfusion therapy of an occluded coronary artery. It is characterized by damage and dysfunction of the myocardial microvasculature with a no-reflow phenomenon within the infarct zone. While MVO may be demonstrated via a number of different imaging modalities, cardiac MR (CMR) enables accurate identification of MVO and also permits assessment of infarct extent and overall left ventricular function during the same imaging examination. We present a pictorial review of the characteristic appearances of MVO on CMR and highlight the importance of this imaging diagnosis for patient outcome following acute myocardial infarction. PMID:25471092

  16. Non-invasive measurement of cardiac output: evaluation of new infrared absorption spectrometer.

    PubMed

    Baum, M M; Moss, J A; Kumar, S; Wagner, P D

    2006-09-28

    The mass spectrometer (MS) traditionally has been the instrument of choice for measuring cardiac output (Q (T)) non-invasively using the foreign gas uptake method. However, the size and cost of the MS has hampered widespread adoption of this technique outside of the laboratory. Here, we present results, from six normal human subjects at rest and during exercise, of simultaneous Q (T) measurements by an MS and a new, portable infrared (IR) device developed in our laboratories. These measurements are made using on the open-circuit acetylene uptake method. The IR device measures inspired and end-tidal concentrations of acetylene, sulfur hexafluoride, and carbon dioxide by IR absorption spectroscopy with a 10-90% response time of 43 ms; accurate measurements were made down to sample flow rates of 50 mL min(-1). Excellent correlation [Q (T)(IR)=0.98 Q (T)(MS), R(2)=0.94] was observed between instruments across the range from rest to heavy exercise. These results suggest that the IR device, which is small, light-weight, and rugged may enable the foreign gas uptake method to be used in clinical, field, and point-of-care settings for Q (T) measurement. PMID:16326150

  17. High Output Cardiac Failure Resolving after Repair of AV Fistula in a Six-Month-Old

    PubMed Central

    Teomete, Uygar; Gugol, Rubee Anne; Neville, Holly; Dandin, Ozgur; Young, Ming-Lon

    2016-01-01

    Background. Acquired AVF in pediatrics are commonly caused by iatrogenic means, including arterial or venous punctures. These fistulae can cause great hemodynamic stress on the heart as soon as they are created. Case. A six-month-old 25-week gestation infant was referred for respiratory distress. Initial exam revealed tachypnea, tachycardia, and hypertension. There was a bruit noted on her left arm. An ultrasound showed an arteriovenous fistula. Its location, however, precluded intervention because of the high risk for limb-loss. An echocardiogram showed evidence of pulmonary hypertension that was treated with sildenafil and furosemide. However, no improvement was seen. On temporary manual occlusion of the fistula, the patient was noted to have increased her blood pressure and decreased her heart rate, suggesting significant hemodynamic effect of the fistula. The fistula was subsequently ligated and the patient clinically and echocardiographically improved. Conclusion. A patient in high output cardiac failure or pulmonary artery hypertension, especially prematüre patients with preexisting lung disease, should be probed for history of multiple punctures, trauma, or surgery and should have prompt evaluation for AVF. If it can be diagnosed and repaired, most of the cases have been shown to decrease the stress on the heart and reverse the pathologic hemodynamics. PMID:26885434

  18. A computational model-based validation of Guyton's analysis of cardiac output and venous return curves

    NASA Technical Reports Server (NTRS)

    Mukkamala, R.; Cohen, R. J.; Mark, R. G.

    2002-01-01

    Guyton developed a popular approach for understanding the factors responsible for cardiac output (CO) regulation in which 1) the heart-lung unit and systemic circulation are independently characterized via CO and venous return (VR) curves, and 2) average CO and right atrial pressure (RAP) of the intact circulation are predicted by graphically intersecting the curves. However, this approach is virtually impossible to verify experimentally. We theoretically evaluated the approach with respect to a nonlinear, computational model of the pulsatile heart and circulation. We developed two sets of open circulation models to generate CO and VR curves, differing by the manner in which average RAP was varied. One set applied constant RAPs, while the other set applied pulsatile RAPs. Accurate prediction of intact, average CO and RAP was achieved only by intersecting the CO and VR curves generated with pulsatile RAPs because of the pulsatility and nonlinearity (e.g., systemic venous collapse) of the intact model. The CO and VR curves generated with pulsatile RAPs were also practically independent. This theoretical study therefore supports the validity of Guyton's graphical analysis.

  19. Gas mixing apparatus for determining cardiac output by CO2 rebreathing.

    PubMed

    Bassett, D R; Fitton, T R

    1995-12-01

    The carbon dioxide rebreathing technique is widely used for determination of cardiac output during exercise. The equilibration method of Collier et at. (J. Appl. Physiol. 9:25, 1956) is generally preferred over the exponential method of Defares (J. Appl. Physiol. 13:159, 1968). However, the equilibration method requires the volume and initial CO2 percentage in the rebreathing bag to be adjusted according to the work rate. A device for mixing two gases (100% O2 and 20% CO2/80% O2) was constructed for this purpose. Multistage regulators are attached to the gas tanks and connected to a medical gas mixer via high-pressure air hoses. A variable time-delay switch causes a solenoid valve to open for 1.0-10s to deliver a predetermined gas volume. The device was found to accurately deliver a preset volume and concentration of gas to the rebreathing bag. A gas mixing apparatus simplifies the equilibration CO2 rebreathing technique by allowing the investigator to easily select the initial volume and percentage of CO2. PMID:8614328

  20. High Output Cardiac Failure Resolving after Repair of AV Fistula in a Six-Month-Old.

    PubMed

    Teomete, Uygar; Gugol, Rubee Anne; Neville, Holly; Dandin, Ozgur; Young, Ming-Lon

    2016-01-01

    Background. Acquired AVF in pediatrics are commonly caused by iatrogenic means, including arterial or venous punctures. These fistulae can cause great hemodynamic stress on the heart as soon as they are created. Case. A six-month-old 25-week gestation infant was referred for respiratory distress. Initial exam revealed tachypnea, tachycardia, and hypertension. There was a bruit noted on her left arm. An ultrasound showed an arteriovenous fistula. Its location, however, precluded intervention because of the high risk for limb-loss. An echocardiogram showed evidence of pulmonary hypertension that was treated with sildenafil and furosemide. However, no improvement was seen. On temporary manual occlusion of the fistula, the patient was noted to have increased her blood pressure and decreased her heart rate, suggesting significant hemodynamic effect of the fistula. The fistula was subsequently ligated and the patient clinically and echocardiographically improved. Conclusion. A patient in high output cardiac failure or pulmonary artery hypertension, especially prematüre patients with preexisting lung disease, should be probed for history of multiple punctures, trauma, or surgery and should have prompt evaluation for AVF. If it can be diagnosed and repaired, most of the cases have been shown to decrease the stress on the heart and reverse the pathologic hemodynamics. PMID:26885434

  1. The influence of high-velocity circuit resistance training on VO2max and cardiac output.

    PubMed

    Petersen, S R; Haennel, R G; Kappagoda, C T; Belcastro, A N; Reid, D C; Wenger, H A; Quinney, H A

    1989-09-01

    In order to investigate the influence of high-velocity circuit resistance training on maximal aerobic power, maximal stroke volume and cardiac output, and blood lactate removal during recovery, 16 habitually active males were blocked on initial VO2max into either training or control groups. The training group completed two (weeks 1 and 2) or three (weeks 3-6) circuits of 10 variable-resistance hydraulic exercise stations at an exercise: relief ratio of 1:2 on alternate days over six weeks. Angular velocities of movement were maintained at approximately 3.1 rad.s-1. Following training, the VO2max was increased (p less than .01) from 4.32 to 4.68 1.min-1. Maximal stroke volume was increased (p less than .05) from 120 to 129 mL and heart rate response to an absolute submaximal exercise load was decreased (p less than .05) from 153 to 146 beats.min-1. As well, enhanced (p less than .01) removal of lactate from the blood was observed during recovery from exhausting exercise. No changes were observed for control subjects. These results indicate that positive alterations in aerobic and cardiovascular function may be achieved consequent to high-velocity circuit resistance training. PMID:2819610

  2. [A dye densitometry analysis method for noninvasive measurement of cardiac output based on NIRS].

    PubMed

    Lu, Meng-Meng; Wang, Hong-Xuan; Liu, Guang-Da; Xin, Gui-Jie; Yu, Yong; Zha, Yu-Tong

    2013-12-01

    Currently, there exist technology problems in cardiac output (CO) parameter detection clinically, such as invasive and complex operation, as well as possibility of infection and death for patients. In order to solve these problems, a noninvasive and continuous method based on NIRS for CO detection was presented. In this way, the concentration changing of indocyanine green (ICG) dye in the patient's arterial blood was dynamically measured and analyzed, so that the CO could be noninvasively and continuously measured according to the characteristic parameters of dye densitometry curve. While the ICG dye was injected into the patient's body by the median cubital vein, block of photoelectric pulse dye densitometry measurement system as the lower machine acquired pulse wave data and uploaded the data to upper computer. In the scheme, two specialized light sources of LED at 940 and 805 nm were used to capture the signals of sufferer's fingertip pulse wave synchronously and successively. The CO value could then be successfully calculated through drawing complete ICG concentration variation of dye dilution and excretion process and computing mean transmission time (MTT) by upper computer. Compared with the "gold standard" method of thermodilution, the maximum relative error of this method was below 9. 76%, and the mean relative error was below 4. 39%. The result indicates that the method can be used as a kind of convenient operation, noninvasive and continuous solution for clinical CO measurement. PMID:24611365

  3. May-Thurner syndrome: High output cardiac failure as a result of iatrogenic iliac fistula

    PubMed Central

    Singh, Shantanu; Singh, Shivank; Jyothimallika, Juthika; Lynch, Teresa J

    2015-01-01

    May-Thurner syndrome (MTS) also termed iliocaval compression or Cockett-Thomas syndrome is a common, although rarely diagnosed, condition in which the patient has an anatomical variant wherein the right common iliac artery overlies and compresses the left common iliac vein against the fifth lumbar spine resulting in increased risk of iliofemoral deep venous thrombosis. This variant has been shown to be present in over 23% of the population but most go undetected. We present a patient with MTS who developed high output cardiac failure due to an iatrogenic iliac fistula. The patient underwent an extensive workup for a left to right shunt including MRI and arterial duplex in the vascular lab. He was ultimately found to have a 2.1 cm left common iliac artery aneurysm and history of common iliac stent. We took the patient to the operating room for aortogram with placement of an endovascular plug of the left internal iliac artery and aorto-bi-iliac stent graft placement with CO2 and IV contrast. Subsequently the patient underwent successful stent placement in the area that was compressed followed by 6 mo of anticoagulation with warfarin. The flow from the fistula decreased significantly. PMID:25789305

  4. Reliability of a new 4th generation FloTrac algorithm to track cardiac output changes in patients receiving phenylephrine.

    PubMed

    Ji, Fuhai; Li, Jian; Fleming, Neal; Rose, David; Liu, Hong

    2015-08-01

    Phenylephrine is often used to treat intra-operative hypotension. Previous studies have shown that the FloTrac cardiac monitor may overestimate cardiac output (CO) changes following phenylephrine administration. A new algorithm (4th generation) has been developed to improve performance in this setting. We performed a prospective observational study to assess the effects of phenylephrine administration on CO values measured by the 3rd and 4th generation FloTrac algorithms. 54 patients were enrolled in this study. We used the Nexfin, a pulse contour method shown to be insensitive to vasopressor administration, as the reference method. Radial arterial pressures were recorded continuously in patients undergoing surgery. Phenylephrine administration times were documented. Arterial pressure recordings were subsequently analyzed offline using three different pulse contour analysis algorithms: FloTrac 3rd generation (G3), FloTrac 4th generation (G4), and Nexfin (nf). One minute of hemodynamic measurements was analyzed immediately before phenylephrine administration and then repeated when the mean arterial pressure peaked. A total of 157 (4.6 ± 3.2 per patient, range 1-15) paired sets of hemodynamic recordings were analyzed. Phenylephrine induced a significant increase in stroke volume (SV) and CO with the FloTrac G3, but not with FloTrac G4 or Nexfin algorithms. Agreement between FloTrac G3 and Nexfin was: 0.23 ± 1.19 l/min and concordance was 51.1%. In contrast, agreement between FloTrac G4 and Nexfin was: 0.19 ± 0.86 l/min and concordance was 87.2%. In conclusion, the pulse contour method of measuring CO, as implemented in FloTrac 4th generation algorithm, has significantly improved its ability to track the changes in CO induced by phenylephrine. PMID:25267438

  5. Combined first pass and gated blood pool radionuclide studies in the hemodynamic-cardiac evaluation of patients with low cardiac output

    SciTech Connect

    Abi-Mansour, P.; Fouad, F.M.; Sheeler, L.R.; Bravo, E.L.; MacIntyre, W.J.; Tarazi, R.C.

    1984-01-01

    Cardiac output (CO) is frequently used in the evaluation of cardiac function but low CO does not necessarily reflect heart failure. Similarly, low ejection fraction (EF) can be present in compensated heart diseases. In order to evaluate cardiac performance in relation to systematic hemodynamics, the authors used a multifactorial approach for the determination of CO, EF, pulmonary mean transit time (MTT), ratio of cardiopulmonary volume over total blood volume (CPV/TBV as an index of venous tone) all obtained from a single injection of 99m Tc-HSA. Four different conditions associated with low CO (less than or equal to 2.1 L/min/m/sup 2/) were evaluated. The combined use of CO, EF, MTT and CPV/TBV allowed a better understanding of the myocardial and peripheral circulatory factors associated with low CO states. This is helpful in the selection and follow-up of appropriate therapeutic intervention.

  6. Health insurance and outcomes: comprehensive assessment of health system outputs.

    PubMed

    Perkins, N A

    1991-01-01

    Outcomes analysis in health care has historically meant the examination of clinical results of inpatient hospitalization. In response to climbing health care and health insurance costs, the organization of health care providers, the location of service delivery and reimbursement mechanisms have changed. As the health care industry changes, so too must the definition of outcomes. This article presents a conceptual framework for the analysis of health outcomes as health industry outputs, with an emphasis on the ways in which such outputs are being assessed and improved. PMID:10116955

  7. Low Cardiac Output Leads Hepatic Fibrosis in Right Heart Failure Model Rats

    PubMed Central

    Fujimoto, Yoshitaka; Urashima, Takashi; Shimura, Daisuke; Ito, Reiji; Kawachi, Sadataka; Kajimura, Ichige; Akaike, Toru; Kusakari, Yoichiro; Fujiwara, Masako; Ogawa, Kiyoshi; Goda, Nobuhito; Ida, Hiroyuki; Minamisawa, Susumu

    2016-01-01

    Background Hepatic fibrosis progresses with right heart failure, and becomes cardiac cirrhosis in a severe case. Although its causal factor still remains unclear. Here we evaluated the progression of hepatic fibrosis using a pulmonary artery banding (PAB)-induced right heart failure model and investigated whether cardiac output (CO) is responsible for the progression of hepatic fibrosis. Methods and Results Five-week-old Sprague-Dawley rats divided into the PAB and sham-operated control groups. After 4 weeks from operation, we measured CO by echocardiography, and hepatic fibrosis ratio by pathological examination using a color analyzer. In the PAB group, CO was significantly lower by 48% than that in the control group (78.2±27.6 and 150.1±31.2 ml/min, P<0.01). Hepatic fibrosis ratio and serum hyaluronic acid, an index of hepatic fibrosis, were significantly increased in the PAB group than those in the control group (7.8±1.7 and 1.0±0.2%, P<0.01, 76.2±27.5 and 32.7±7.5 ng/ml, P<0.01). Notably, the degree of hepatic fibrosis significantly correlated a decrease in CO. Immunohistological analysis revealed that hepatic stellate cells were markedly activated in hypoxic areas, and HIF-1α positive hepatic cells were increased in the PAB group. Furthermore, by real-time PCR analyses, transcripts of profibrotic and fibrotic factors (TGF-β1, CTGF, procollargen I, procollargen III, MMP 2, MMP 9, TIMP 1, TIMP 2) were significantly increased in the PAB group. In addition, western blot analyses revealed that the protein level of HIF-1α was significantly increased in the PAB group than that in the control group (2.31±0.84 and 1.0±0.18 arbitrary units, P<0.05). Conclusions Our study demonstrated that low CO and tissue hypoxia were responsible for hepatic fibrosis in right failure heart model rats. PMID:26863419

  8. Assessment of Electrosurgery Burns in Cardiac Surgery

    PubMed Central

    Jalali, Seyyed Mehdi; Moradi, Mohammad; Khalaj, Alireza; Pazouki, Alireza; Tamannaie, Zeinab; Ghanbari, Sajjad

    2015-01-01

    Background: Monopolar surgery is applied mostly in major operations, while bipolar is used in delicate ones. Attention must be paid in electrosurgery application to avoid electrical burns. Objectives: We aimed to assess factors associated with electrosurgery burns in cardiac surgery operating rooms. Patients and Methods: This was a case-control study in which two groups of 150 patients undergoing cardiac surgery in Imam Khomeini Hospital were recruited. Several factors like gender, age, operation duration, smoking, diseases, infection, atopia, , immunosuppressive drugs use, hepatic cirrhosis, and pulmonary diseases were compared between the two groups. Patients were observed for 24 hours for development of any burn related to the operation. Data was analyzed using SPSS v.11.5, by Chi square and T-test. Results: Patients in the two groups were similar except for two factors. DM and pulmonary diseases which showed significant differences (P = 0.005 and P = 0.002 respectively). Seventy-five patients from controls and 35 from the study group developed burns, which was significant (P ˂ 0.0001). Conclusions: None of the factors were significantly related to developing burns. The differences between the two groups highlights the importance of systems modifications to lessen the incidence of burns. PMID:26839854

  9. Methodology of method comparison studies evaluating the validity of cardiac output monitors: a stepwise approach and checklist.

    PubMed

    Montenij, L J; Buhre, W F; Jansen, J R; Kruitwagen, C L; de Waal, E E

    2016-06-01

    The validity of each new cardiac output (CO) monitor should be established before implementation in clinical practice. For this purpose, method comparison studies investigate the accuracy and precision against a reference technique. With the emergence of continuous CO monitors, the ability to detect changes in CO, in addition to its absolute value, has gained interest. Therefore, method comparison studies increasingly include assessment of trending ability in the data analysis. A number of methodological challenges arise in method comparison research with respect to the application of Bland-Altman and trending analysis. Failure to face these methodological challenges will lead to misinterpretation and erroneous conclusions. We therefore review the basic principles and pitfalls of Bland-Altman analysis in method comparison studies concerning new CO monitors. In addition, the concept of clinical concordance is introduced to evaluate trending ability from a clinical perspective. The primary scope of this review is to provide a complete overview of the pitfalls in CO method comparison research, whereas other publications focused on a single aspect of the study design or data analysis. This leads to a stepwise approach and checklist for a complete data analysis and data representation. PMID:27199309

  10. Dynamic asymmetries of cardiac output transients in response to muscular exercise in man.

    PubMed Central

    Yoshida, T; Whipp, B J

    1994-01-01

    1. We determined the kinetics of cardiac output (Q) with respect to oxygen uptake (VO2) at the on- and off-transients of constant-load exercise. Six subjects performed constant-load exercise which consisted of 5 min rest, 5 min one-legged pedalling at 50 W and a 5 min recovery period. 2. The transient responses were characterized by first-order kinetics. There was no significant difference between the time constants for VO2 (tau VO2) at the on- (33.9 +/- 3.5 s, mean +/- S.E.M.) and off-transient (37.2 +/- 2.9 s). The time constant for Q (tau Q, 29.4 +/- 3.2 s) was consistently shorter than tau VO2 at the on-transient. However, tau Q was appreciably longer at the off-transient (44.3 +/- 3.6 s) than the on-transient. 3. The results support the contention that the time constant for the on-transient of Q is appreciably faster than that for VO2 and hence there seems little justification for the notion that the time constants for the kinetics of VO2 are determined by the limitations of blood flow in the transient. The asymmetry of Q kinetics, with the off-transient tau Q being appreciably slower than the on-transient tau Q, serves to maintain a sufficiently high oxygen flow to the muscle during recovery from exercise at a time when the muscle oxygen uptake remains high. PMID:7869250

  11. Subject-specific Model Estimation of Cardiac Output and Blood Volume During Hemorrhage

    PubMed Central

    Neal, Maxwell Lewis; Bassingthwaighte, James B.

    2010-01-01

    We have developed a novel method for estimating subject-specific hemodynamics during hemorrhage. First, a mathematical model representing a closed-loop circulation and baroreceptor feedback system was parameterized to match the baseline physiology of individual experimental subjects by fitting model results to 1 min of pre-injury data. This automated parameterization process matched pre-injury measurements within 1.4 ± 1.3% SD. Tuned parameters were then used in similar open-loop models to simulate dynamics post-injury. Cardiac output (CO) estimates were obtained continuously using post-injury measurements of arterial blood pressure (ABP) and heart rate (HR) as inputs to the first open-loop model. Secondarily, total blood volume (TBV) estimates were obtained by summing the blood volumes in all the circulatory segments of a second open-loop model that used measured CO as an additional input. We validated the estimation method by comparing model CO results to flowprobe measurements in 14 pigs. Overall, CO estimates had a Bland-Altman bias of −0.30 l/min with upper and lower limits of agreement 0.80 and −1.40 l/min. The negative bias is likely due to overestimation of the peripheral resistance response to hemorrhage. There was no reference measurement of TBV; however, the estimates appeared reasonable and clearly predicted survival versus death during the post-hemorrhage period. Both open-loop models ran in real time on a computer with a 2.4 GHz processor, and their clinical applicability in emergency care scenarios is discussed. PMID:17846886

  12. Predictors of Post Pericardiotomy Low Cardiac Output Syndrome in Patients With Pericardial Effusion

    PubMed Central

    Sabzi, Feridoun; Faraji, Reza

    2015-01-01

    Introduction: Pathological involvement of pericardium by any disease that resulting in effusion may require decompression and pericardiectomy. The current article describes rare patients with effusion who after pericadiectomy and transient hemodynamic improvement rapidly developed progressive heart failure and subsequent multi organ failure. Methods: During periods of five years, 423 patients in our hospital underwent pericardiotomy for decompression of effusion. The clinical characteristics of those patient with postoperative low cardiac output (B group) (14 cases) recorded and compared with other patients without this postoperative complication (A group) by test and X2. Significant variables in invariables (P≤0.1) entered in logistic regression analysis and odd ratio of these significant variables obtained. Results: Idiopathic pericardial effusion, malignancy, renal failure, connective tissue disease, viral pericarditis was found in 125 patients (27%), 105 patients (25.4%), 65 patients (15.6%), 50 (17.1%) and 10 (2.4%) of patients subsequently. The factors that predict post-operative death in logistic regression analysis were malignancy, radiotherapy, constrictive pericarditis inotropic drug using IABP using, pre-operative EF and pericardial calcification. Conclusion: Certain preoperative variables such as malignancy, radiotherapy, low EF, calcified pericardium and connective tissue disease are associated with POLCOS and post-operative risk of death. This paradoxical response to pericardial decompression may be more frequent than currently appreciated. Its cause may relate to the sudden removal of the chronic external ventricular support from the effusion or thicken pericardium resulting in ventricular dilatation and failure or intra operative myocardial injury due to pericardiectomy of calcified pericardium, radiation and cardiomyopathy. PMID:25859311

  13. Cardiac output distribution in miniature swine during locomotory exercise to VO/sub 3max/

    SciTech Connect

    Armstrong, R.B.; Delp, M.D.; Laughlin, M.H.

    1986-03-01

    Distribution of cardiac output (CO) was studied in miniature swine (22 +/- 1 kg) during level treadmill exercise up to the speed (17.7 km/hr) that elicited maximal oxygen consumption (VO/sub 2max/) (60 +/- 4 m1/min/kg). COs and tissue blood flows (BFs) were measured with the radiolabelled microsphere technique. CO increased from a preexercise value of 2.1 +/- 0.5 1/min up to 9.9 +/- 0.5 1/min at VO/sub 2max/. In preexercise standing 43% of CO went to skeletal muscle, which comprised 36 +/- 1% of body mass, 42% to viscera (12 +/- 1% mass), 5% to brain, heart, and lungs (2% +/- 0.1% mass), and 10% to skin and skeleton (35 +/- 2% mass). Preexercise could not be considered resting because of the animals' excitability. Skeletal muscle BF increased progressively with speed up to VO/sub 2max/, both in absolute terms and in percent CO. At VO/sub 2max/, 88% of CO went to muscle, 3% to viscera, 8% to brain, heart and lungs, and 1% to skin and skeleton. Thus, at VO/sub 2max/ only 4% of CO went to the inactive tissues, which constituted 47% of body mass. In 2 pigs that ran at speeds above 17 km/hr, total muscle BF leveled off at VO/sub 2max/. These findings demonstrate that muscle BF progressively increases up to VO/sub 2max/, and that VO/sub 2/ levels off at the same intensity as muscle flow.

  14. High-output cardiac failure in a fetus with thanatophoric dysplasia associated with large placental chorioangioma: case report.

    PubMed

    Akercan, Fuat; Oncul Seyfettinoglu, Sevtap; Zeybek, Burak; Cirpan, Teksin

    2012-05-01

    Placental chorioangioma is an angioma arising from chorionic tissue. Fetal thanatophoric dysplasia is a lethal skeletal dysplasia due to mutation of fibroblast growth factor receptor 3 gene. These two conditions are rare and their coexistence in a given fetus is even rarer. We present a case of a fetus with thanatophoric dysplasia having high-output cardiac failure due to a large placental chorioangioma. PMID:22508320

  15. Environmental risk assessments for transgenic crops producing output trait enzymes

    PubMed Central

    Tuttle, Ann; Shore, Scott; Stone, Terry

    2009-01-01

    The environmental risks from cultivating crops producing output trait enzymes can be rigorously assessed by testing conservative risk hypotheses of no harm to endpoints such as the abundance of wildlife, crop yield and the rate of degradation of crop residues in soil. These hypotheses can be tested with data from many sources, including evaluations of the agronomic performance and nutritional quality of the crop made during product development, and information from the scientific literature on the mode-of-action, taxonomic distribution and environmental fate of the enzyme. Few, if any, specific ecotoxicology or environmental fate studies are needed. The effective use of existing data means that regulatory decision-making, to which an environmental risk assessment provides essential information, is not unnecessarily complicated by evaluation of large amounts of new data that provide negligible improvement in the characterization of risk, and that may delay environmental benefits offered by transgenic crops containing output trait enzymes. PMID:19924556

  16. Early non-invasive cardiac output monitoring in hemodynamically unstable intensive care patients: A multi-center randomized controlled trial

    PubMed Central

    2011-01-01

    Introduction Acute hemodynamic instability increases morbidity and mortality. We investigated whether early non-invasive cardiac output monitoring enhances hemodynamic stabilization and improves outcome. Methods A multicenter, randomized controlled trial was conducted in three European university hospital intensive care units in 2006 and 2007. A total of 388 hemodynamically unstable patients identified during their first six hours in the intensive care unit (ICU) were randomized to receive either non-invasive cardiac output monitoring for 24 hrs (minimally invasive cardiac output/MICO group; n = 201) or usual care (control group; n = 187). The main outcome measure was the proportion of patients achieving hemodynamic stability within six hours of starting the study. Results The number of hemodynamic instability criteria at baseline (MICO group mean 2.0 (SD 1.0), control group 1.8 (1.0); P = .06) and severity of illness (SAPS II score; MICO group 48 (18), control group 48 (15); P = .86)) were similar. At 6 hrs, 45 patients (22%) in the MICO group and 52 patients (28%) in the control group were hemodynamically stable (mean difference 5%; 95% confidence interval of the difference -3 to 14%; P = .24). Hemodynamic support with fluids and vasoactive drugs, and pulmonary artery catheter use (MICO group: 19%, control group: 26%; P = .11) were similar in the two groups. The median length of ICU stay was 2.0 (interquartile range 1.2 to 4.6) days in the MICO group and 2.5 (1.1 to 5.0) days in the control group (P = .38). The hospital mortality was 26% in the MICO group and 21% in the control group (P = .34). Conclusions Minimally-invasive cardiac output monitoring added to usual care does not facilitate early hemodynamic stabilization in the ICU, nor does it alter the hemodynamic support or outcome. Our results emphasize the need to evaluate technologies used to measure stroke volume and cardiac output--especially their impact on the process of care--before any large-scale outcome studies are attempted. Trial Registration The study was registered at ClinicalTrials.gov (Clinical Trials identifier NCT00354211) PMID:21676229

  17. Addressing Assumptions for the Use of Non-invasive Cardiac Output Measurement Techniques During Exercise in COPD.

    PubMed

    Perrault, Hélène; Richard, Ruddy; Kapchinsky, Sophia; Baril, Jacinthe; Bourbeau, Jean; Taivassalo, Tanja

    2016-02-01

    The multifactorial functional limitation of COPD increasingly demonstrates the need for an integrated circulatory assessment. In this study cardiac output (Qc) derived from non-inert (CO2-RB), inert (N2O-RB) gas rebreathing approaches and bioimpedance were compared to examine the limitations of currently available non-invasive techniques for exercise Qc determination in patients with chronic lung disease. Thirteen COPD patients (GOLD II-III) completed three constant cycling bouts at 20, 35, and 50% of peak work on two occasions to assess Qc with bioimpedance as well as using CO2-RB and N2O-RB for all exercise tests. Results showed significantly lower Qc using the N2O-RB or end-tidal CO2-derived Qc compared to the PaCO2-derived CO2-RB or the bioimpedance at rest and for all exercise intensities. End-tidal CO2-derived values are however not statistically different from those obtained using inert-gas rebreathing. This study show that in COPD patients, CO2-rebreathing Qc values obtained using PaCO2 contents which account for any gas exchange impairment or inadequate gas mixing are similar to those obtained using thoracic bioimpedance. Alternately, the lower values for N2O rebreathing derived Qc indicates the inability of this technique to account for gas exchange impairment in the computation of Qc. These findings indicate that the choice of a gas rebreathing technique to measure Qc in patients must be dictated by the ability to include in the derived computations a correction for either gas exchange inadequacies and/or a vascular shunt. PMID:26408087

  18. Effect of hemorrhage on cardiac output, vasopressin, aldosterone, and diuresis during immersion in men

    NASA Technical Reports Server (NTRS)

    Greenleaf, J. E.; Simanonok, K.; Bernauer, E. M.; Wade, C. E.; Keil, L. C.

    1992-01-01

    The purpose of this research was to test the hypotesis that a reduction in blood volume would attenuate or eliminate immersion-induced increases in cardiac output (Q(sub co)) and urine excretion, and to investigate accompanying vasoactive and fluid-electrolyte hormonal responses. Eight men (19-23 yr) were supine during a 2-hr control period in air, and then sat for 5-hr test periods in air at 20 C (dry control, DC); water at 34.5 C (wet control, WC); and water (34.5 C) after hemorrhage (WH) of 14.8 plus or minus 0.3 percent of their blood volume. Blood volume was -11.6 plus or minus 0.6 percent at immersion (time 0). Mean (bar-X hrs 1-5) Q(sub co) was unchanged in WC (5.3 plus or minus 0.01 l/min) and in WH (4.5 plus or minus 0.1 l/min), but decreased (P less than 0.05) in DC to 3.6 plus or minus 0.1 l/min. Mean urine excretion rates were 1.0 plus or minus 0.2 ml/min for DC and 1.1 plus or minus 0.2 ml/min for WH; both were lower (P less than 0.05) than that for WC of 2.0 plus or minus 0.4 ml/min. Plasma (Na+) and (Osm) were unchanged in all experiments. Mean plasma vasopressin (PVP) (bar-X hrs 1-5) was 1.1 plus or minus 0.1 pg/ml in WC, and higher (P less than 0.05) in DC (2.1 plus or minus 0.2 pg/ml)and WH (2.1 plus or minus 0.1 pg/ml); it was unchanged during air and water test periods. Thus, hemorrhage attenuated the immersion-induced increase in Q(sub co), eliminated the WC diuresis, maintained plasma renin activity and PVP at DC levels and did not change immersion-induced aldosterone suppression; the osmotic diuresis during control immersion is apparently not due to either aldosterone suppression or vasopressin suppression.

  19. Predictors of low cardiac output syndrome after isolated coronary artery bypass grafting.

    PubMed

    Ding, WenJun; Ji, Qiang; Shi, YunQing; Ma, RunHua

    2015-01-01

    Low cardiac output syndrome (LCOS) is one of the most important complications following coronary artery bypass grafting (CABG) and results in higher morbidity and mortality. However, few reports have focused on the predictors of LCOS following CABG. This study aimed to evaluate the predictors of LCOS following isolated CABG through the review of 1524 consecutive well-documented patients in a single center, retrospective trial.The relevant preoperative and intraoperative data of patients with complete information from medical records undergoing isolated CABG from January 2010 to December 2013 in our center were investigated and retrospectively analyzed. LCOS was considered when the following criteria were met: signs of impairment of body perfusion and need for inotropic support with vasoactive drugs or mechanical circulatory support with an intra-aortic balloon pump to maintain systolic blood pressure greater than 90 mmHg.LCOS developed in 205 patients following CABG, accounting for 13.5% of the total population. The in-hospital mortality in the LCOS group was significantly higher than that in the non-LCOS group (25.4% versus 1.8%, P < 0.0001). In addition to the length of ICU stay and postoperative hospital stay, LCOS was correlated with negative cerebral, respiratory and renal outcomes. Through univariate analysis and then logistic regression analysis, the predictors of LCOS following CABG included older age (age > 65 years) (OR = 1.85, 95%CI 1.27-3.76), impaired left ventricular function (OR = 2.05, 95%CI 1.53-4.54), on-pump CABG (OR = 2.16, 95%CI 1.53-4.86), emergent CPB (OR = 9.15, 95%CI 3.84-16.49), and incomplete revascularization (OR = 2.62, 95%CI 1.79-5.15).LCOS following isolated CABG caused higher mortality, higher rates of morbidity, and longer ICU and postoperative hospital stays. Older age, impaired left ventricular function, on-pump CABG, emergent CPB, and incomplete revascularization were identified as 5 predictors of LCOS following isolated CABG surgery. PMID:25740396

  20. Bioreactance: a new tool for cardiac output and thoracic fluid content monitoring during hemodialysis.

    PubMed

    Kossari, Niloufar; Hufnagel, Gilles; Squara, Pierre

    2009-10-01

    Outpatient hemodialysis therapy (HD) can be associated with hemodynamic compromise. Bioreactance has recently been shown to provide accurate, noninvasive, continuous, measurements of cardiac output (CO) and thoracic impedance (Zo) from which thoracic fluid content (TFC) can be derived assuming TFC=1000/Zo. This study was designed to evaluate the changes in TFC in comparison with the traditional indices of fluid removal (FR) and to understand the trends in CO changes in HD patients. Minute-by-minute changes in TFC and CO were prospectively collected using the bioreactance system (NICOM) in HD patients of a single unit. Changes in body weight (DeltaW), hematocrit (DeltaHct), and amount of FR were also measured. Twenty-five patients (age 77 +/- 11 years) were included. The TFC decreased in all patients by an average of 5.4 +/- 7.9 kohm(-1), weight decreased by 1.48 +/- 0.98 kg, and FR averaged 2.07 +/- 1.93 L over a 3- to 4-hour HD session. There were good correlations between DeltaTFC and DeltaW (R=0.80, P<0.0001) and FR (R=0.85, P<0.0001). DeltaHct (4.13 +/- 3.42%) was poorly correlated with DeltaTFC (R=0.35, P=0.12) and FR (R=0.40, P=0.07). The regression line between FR and TFC yielded FR=1.0024-0.1985TFC; thus, a 1 kohm(-1) change of Zo correlates with an approximately 200 mL change in total body water. The change in CO (-0.52 +/- 0.49 L/min m(2)) during HD did not correlate with FR (R=0.15, P=NS). Changes in TFC represented the monitored variable most closely related to FR. CO remained fairly constant in this stable patient cohort. Further studies in high-risk patients are warranted to understand whether TFC and CO monitoring can improve HD session management. PMID:19758300

  1. Effects of hypertrophic and dilated cardiomyopathy mutations on power output by human β-cardiac myosin.

    PubMed

    Spudich, James A; Aksel, Tural; Bartholomew, Sadie R; Nag, Suman; Kawana, Masataka; Yu, Elizabeth Choe; Sarkar, Saswata S; Sung, Jongmin; Sommese, Ruth F; Sutton, Shirley; Cho, Carol; Adhikari, Arjun S; Taylor, Rebecca; Liu, Chao; Trivedi, Darshan; Ruppel, Kathleen M

    2016-01-01

    Hypertrophic cardiomyopathy is the most frequently occurring inherited cardiovascular disease, with a prevalence of more than one in 500 individuals worldwide. Genetically acquired dilated cardiomyopathy is a related disease that is less prevalent. Both are caused by mutations in the genes encoding the fundamental force-generating protein machinery of the cardiac muscle sarcomere, including human β-cardiac myosin, the motor protein that powers ventricular contraction. Despite numerous studies, most performed with non-human or non-cardiac myosin, there is no clear consensus about the mechanism of action of these mutations on the function of human β-cardiac myosin. We are using a recombinantly expressed human β-cardiac myosin motor domain along with conventional and new methodologies to characterize the forces and velocities of the mutant myosins compared with wild type. Our studies are extending beyond myosin interactions with pure actin filaments to include the interaction of myosin with regulated actin filaments containing tropomyosin and troponin, the roles of regulatory light chain phosphorylation on the functions of the system, and the possible roles of myosin binding protein-C and titin, important regulatory components of both cardiac and skeletal muscles. PMID:26792326

  2. Pulse Wave Velocity and Cardiac Output vs. Heart Rate in Patients with an Implanted Pacemaker Based on Electric Impedance Method Measurement

    NASA Astrophysics Data System (ADS)

    Soukup, Ladislav; Vondra, Vlastimil; Viščor, Ivo; Jurák, Pavel; Halámek, Josef

    2013-04-01

    The methods and device for estimation of cardiac output and measurement of pulse wave velocity simultaneously is presented here. The beat-to-beat cardiac output as well as pulse wave velocity measurement is based on application of electrical impedance method on the thorax and calf. The results are demonstrated in a study of 24 subjects. The dependence of pulse wave velocity and cardiac output on heart rate during rest in patients with an implanted pacemaker was evaluated. The heart rate was changed by pacemaker programming while neither exercise nor drugs were applied. The most important result is that the pulse wave velocity, cardiac output and blood pressure do not depend significantly on heart rate, while the stroke volume is reciprocal proportionally to the heart rate.

  3. Femoral Blood Flow and Cardiac Output During Blood Flow Restricted Leg Press Exercise

    NASA Technical Reports Server (NTRS)

    Everett, M. E.; Hackney, K.; Ploutz-Snyder, L.

    2011-01-01

    Low load blood flow restricted resistance exercise (LBFR) causes muscle hypertrophy that may be stimulated by the local ischemic environment created by the cuff pressure. However, local blood flow (BF) during such exercise is not well understood. PURPOSE: To characterize femoral artery BF and cardiac output (CO) during leg press exercise (LP) performed at a high load (HL) and low load (LL) with different levels of cuff pressure. METHODS: Eleven subjects (men/women 4/7, age 31.4+/-12.8 y, weight 68.9+/-13.2 kg, mean+/-SD) performed 3 sets of supine left LP to fatigue with 90 s of rest in 4 conditions: HL (%1-RM/cuff pressure: 80%/0); LL (20%/0); LBFR(sub DBP) (20%/1.3 x diastolic blood pressure, BP); LBFR(sub SBP) (20%/1.3 x supine systolic BP). The cuff remained inflated throughout the LBFR exercise sessions. Artery diameter, velocity time integral (VTI), and stroke volume (SV) were measured using Doppler ultrasound at rest and immediately after each set of exercise. Heart rate (HR) was monitored using a 3-lead ECG. BF was calculated as VTI x vessel cross-sectional area. CO was calculated as HR x SV. The data obtained after each set of exercise were averaged and used for analyses. Multi-level modeling was used to determine the effect of exercise condition on dependent variables. Statistical significance was set a priori at p< 0.05. RESULTS: Artery diameter did not change from baseline. BF increased (p<0.05) after exercise in each condition except LBFR(sub SBP) in the order of HL (12.73+/-1.42 cm3,mean+/-SE) > LL (9.92+/-0.82 cm3) > LBFR(sub dBP)(6.47+/-0.79 cm3) > LBFR(sub SBP) (3.51+/-0.59 cm3). Blunted exercise induced increases occurred in HR, SV, and CO after LBFR compared to HL and LL. HR increased 45% after HL and LL and 28% after LBFR (p<0.05), but SV increased (p<0.05) only after HL. Consequently, the increase (p<0.05) in CO was greater in HL and LL (approximately 3 L/min) than in LBFR (approximately 1 L/min). CONCLUSION: BF during LBFR(sub SBP) was 1/3 of that observed in LL, which supports the hypothesis that local ischemia stimulates the LBFR hypertrophic response. As the cuff did not compress the artery, the ischemia may have occurred because of the blunted rise in CO or because arterial BP cannot overcome the cuff pressure. As LBFR(sub DBP) effectively reduced BF and CO with cuff pressures less than systolic BP, future studies should investigate the hypertrophic potential of LBFR at even lower cuff pressures.

  4. Scintigraphic assessment of heterotopic cardiac transplants

    SciTech Connect

    Wilson, M.A.; Kahn, D.R.

    1981-01-01

    Patients receiving heterotopic (''piggyback'') cardiac transplants, when the patient's own and transplanted donor hearts are connected in parallel, present special problems in determining their relative contributions to total cardiac function. Three patients who had transplants because of intractable heart failure were studied using first pass and gated equilibrium technetium-99m-labeled blood pool scintigraphy. In one patient, thallium-201 myocardial perfusion scans were obtained. These nuclear cardiology techniques provided anatomic and functional information noninvasively that proved helpful in patient management.

  5. Scintigraphic assessment of heterotopic cardiac transplants

    SciTech Connect

    Wilson, M.A.; Kahn, D.R.

    1981-10-01

    Patients receiving heterotopic (piggyback) cardiac transplants, when the patient's own and transplanted donor hearts are connected in parallel, present special problems in determining their relative contributions to total cardiac function. Three patients who had transplants because of intractable heart failure were studied using first pass and gated equilibrium technetium-99m-labeled blood pool scintigraphy. In one patient, thallium-201 myocardial perfusion scans were obtained. These nuclearcardiology techniques provided anatomic and functional information noninvasively that proved helpful in patient management.

  6. Assessing Depression in Cardiac Patients: What Measures Should Be Considered?

    PubMed Central

    Ceccarini, M.; Manzoni, G. M.; Castelnuovo, G.

    2014-01-01

    It is highly recommended to promptly assess depression in heart disease patients as it represents a crucial risk factor which may result in premature deaths following acute cardiac events and a more severe psychopathology, even in cases of subsequent nonfatal cardiac events. Patients and professionals often underestimate or misjudge depressive symptomatology as cardiac symptoms; hence, quick, reliable, and early mood changes assessments are warranted. Failing to detect depressive signals may have detrimental effects on these patients' wellbeing and full recovery. Choosing gold-standard depression investigations in cardiac patients that fit a hospitalised cardiac setting well is fundamental. This paper will examine eight well established tools following Italian and international guidelines on mood disorders diagnosis in cardiac patients: the Hospital Anxiety and Depression Scale (HADS), the Cognitive Behavioural Assessment Hospital Form (CBA-H), the Beck Depression Inventory (BDI), the two and nine-item Patient Health Questionnaire (PHQ-2, PHQ-9), the Depression Interview and Structured Hamilton (DISH), the Hamilton Rating Scale for Depression (HAM-D/HRSD), and the Composite International Diagnostic Interview (CIDI). Though their strengths and weaknesses may appear to be homogeneous, the BDI-II and the PHQ are more efficient towards an early depression assessment within cardiac hospitalised patients. PMID:24649359

  7. At high cardiac output, diesel exhaust exposure increases pulmonary vascular resistance and decreases distensibility of pulmonary resistive vessels.

    PubMed

    Wauters, Aurélien; Vicenzi, Marco; De Becker, Benjamin; Riga, Jean-Philippe; Esmaeilzadeh, Fatemeh; Faoro, Vitalie; Vachiéry, Jean-Luc; van de Borne, Philippe; Argacha, Jean-François

    2015-12-15

    Air pollution has recently been associated with the development of acute decompensated heart failure, but the underlying biological mechanisms remain unclear. A pulmonary vasoconstrictor effect of air pollution, combined with its systemic effects, may precipitate decompensated heart failure. The aim of the present study was to investigate the effects of acute exposure to diesel exhaust (DE) on pulmonary vascular resistance (PVR) under resting and stress conditions but also to determine whether air pollution may potentiate acquired pulmonary hypertension. Eighteen healthy male volunteers were exposed to ambient air (AA) or dilute DE with a particulate matter of <2.5 μm concentration of 300 μg/m(3) for 2 h in a randomized, crossover study design. The effects of DE on PVR, on the coefficient of distensibilty of pulmonary vessels (α), and on right and left ventricular function were evaluated at rest (n = 18), during dobutamine stress echocardiography (n = 10), and during exercise stress echocardiography performed in hypoxia (n = 8). Serum endothelin-1 and fractional exhaled nitric oxide were also measured. At rest, exposure to DE did not affect PVR. During dobutamine stress, the slope of the mean pulmonary artery pressure-cardiac output relationship increased from 2.8 ± 0.5 mmHg · min · l (-1) in AA to 3.9 ± 0.5 mmHg · min · l (-1) in DE (P < 0.05) and the α coefficient decreased from 0.96 ± 0.15 to 0.64 ± 0.12%/mmHg (P < 0.01). DE did not further enhance the hypoxia-related upper shift of the mean pulmonary artery pressure-cardiac output relationship. Exposure to DE did not affect serum endothelin-1 concentration or fractional exhaled nitric oxide. In conclusion, acute exposure to DE increased pulmonary vasomotor tone by decreasing the distensibility of pulmonary resistive vessels at high cardiac output. PMID:26497960

  8. Reliability of continuous cardiac output measurement during intra-abdominal hypertension relies on repeated calibrations: an experimental animal study

    PubMed Central

    Gruenewald, Matthias; Renner, Jochen; Meybohm, Patrick; Höcker, Jan; Scholz, Jens; Bein, Berthold

    2008-01-01

    Introduction Monitoring cardiac output (CO) may allow early detection of haemodynamic instability, aiming to reduce morbidity and mortality in critically ill patients. Continuous cardiac output (CCO) monitoring is recommended in septic or postoperative patients with high incidences of intra-abdominal hypertension (IAH). The aim of the present study was to compare the agreement between three CCO methods and a bolus thermodilution CO technique during acute IAH and volume loading. Methods Ten pigs were anaesthetised and instrumented for haemodynamic measurements. Cardiac output was obtained using CCO by pulse power analysis (PulseCO; LiDCO monitor), using CCO by pulse contour analysis (PCCO; PiCCO monitor) and using CCO by pulmonary artery catheter thermodilution (CCOPAC), and was compared with bolus transcardiopulmonary thermodilution CO (COTCP) at baseline, after fluid loading, at IAH and after an additional fluid loading at IAH. Whereas PulseCO was only calibrated at baseline, PCCO was calibrated at each experimental step. Results PulseCO and PCCO underestimated CO, as the overall bias ± standard deviation was 1.0 ± 1.5 l/min and 1.0 ± 1.1 l/min compared with COTCP. A clinically accepted agreement between all of the CCO methods and COTCP was observed only at baseline. Whereas IAH did not influence the CO, increased CO following fluid loading at IAH was only reflected by CCOPAC and COTCP, not by uncalibrated PulseCO and PCCO. After recalibration, PCCO was comparable with COTCP. Conclusions The CO obtained by uncalibrated PulseCO and PCCO failed to agree with COTCP during IAH and fluid loading. In the critically ill patient, recalibration of continuous arterial waveform CO methods should be performed after fluid loading or before a major change in therapy is initiated. PMID:18957114

  9. The thick left ventricular wall of the giraffe heart normalises wall tension, but limits stroke volume and cardiac output.

    PubMed

    Smerup, Morten; Damkjær, Mads; Brøndum, Emil; Baandrup, Ulrik T; Kristiansen, Steen Buus; Nygaard, Hans; Funder, Jonas; Aalkjær, Christian; Sauer, Cathrine; Buchanan, Rasmus; Bertelsen, Mads Frost; Østergaard, Kristine; Grøndahl, Carsten; Candy, Geoffrey; Hasenkam, J Michael; Secher, Niels H; Bie, Peter; Wang, Tobias

    2016-02-01

    Giraffes - the tallest extant animals on Earth - are renowned for their high central arterial blood pressure, which is necessary to secure brain perfusion. Arterial pressure may exceed 300 mmHg and has historically been attributed to an exceptionally large heart. Recently, this has been refuted by several studies demonstrating that the mass of giraffe heart is similar to that of other mammals when expressed relative to body mass. It thus remains unexplained how the normal-sized giraffe heart generates such massive arterial pressures. We hypothesized that giraffe hearts have a small intraventricular cavity and a relatively thick ventricular wall, allowing for generation of high arterial pressures at normal left ventricular wall tension. In nine anaesthetized giraffes (495±38 kg), we determined in vivo ventricular dimensions using echocardiography along with intraventricular and aortic pressures to calculate left ventricular wall stress. Cardiac output was also determined by inert gas rebreathing to provide an additional and independent estimate of stroke volume. Echocardiography and inert gas-rebreathing yielded similar cardiac outputs of 16.1±2.5 and 16.4±1.4 l min(-1), respectively. End-diastolic and end-systolic volumes were 521±61 ml and 228±42 ml, respectively, yielding an ejection fraction of 56±4% and a stroke volume of 0.59 ml kg(-1). Left ventricular circumferential wall stress was 7.83±1.76 kPa. We conclude that, relative to body mass, a small left ventricular cavity and a low stroke volume characterizes the giraffe heart. The adaptations result in typical mammalian left ventricular wall tensions, but produce a lowered cardiac output. PMID:26643090

  10. Numerical observer for cardiac motion assessment using machine learning

    NASA Astrophysics Data System (ADS)

    Marin, Thibault; Kalayeh, Mahdi M.; Pretorius, P. H.; Wernick, Miles N.; Yang, Yongyi; Brankov, Jovan G.

    2011-03-01

    In medical imaging, image quality is commonly assessed by measuring the performance of a human observer performing a specific diagnostic task. However, in practice studies involving human observers are time consuming and difficult to implement. Therefore, numerical observers have been developed, aiming to predict human diagnostic performance to facilitate image quality assessment. In this paper, we present a numerical observer for assessment of cardiac motion in cardiac-gated SPECT images. Cardiac-gated SPECT is a nuclear medicine modality used routinely in the evaluation of coronary artery disease. Numerical observers have been developed for image quality assessment via analysis of detectability of myocardial perfusion defects (e.g., the channelized Hotelling observer), but no numerical observer for cardiac motion assessment has been reported. In this work, we present a method to design a numerical observer aiming to predict human performance in detection of cardiac motion defects. Cardiac motion is estimated from reconstructed gated images using a deformable mesh model. Motion features are then extracted from the estimated motion field and used to train a support vector machine regression model predicting human scores (human observers' confidence in the presence of the defect). Results show that the proposed method could accurately predict human detection performance and achieve good generalization properties when tested on data with different levels of post-reconstruction filtering.

  11. 78 FR 36787 - Rechanneling the Current Cardiac Risk Paradigm: Arrhythmia Risk Assessment During Drug...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-19

    ... HUMAN SERVICES Food and Drug Administration Rechanneling the Current Cardiac Risk Paradigm: Arrhythmia... (FDA), the Cardiac Safety Research Consortium, and the International Life Sciences Institute's Health... the Current Cardiac Risk Paradigm: Arrhythmia Risk Assessment During Drug Development Without...

  12. Evaluating cardiac physiology through echocardiography in bottlenose dolphins: using stroke volume and cardiac output to estimate systolic left ventricular function during rest and following exercise.

    PubMed

    Miedler, Stefan; Fahlman, Andreas; Valls Torres, Mónica; Álvaro Álvarez, Teresa; Garcia-Parraga, Daniel

    2015-11-01

    Heart-rate (fH) changes during diving and exercise are well documented for marine mammals, but changes in stroke volume (SV) and cardiac output (CO) are much less known. We hypothesized that both SV and CO are also modified following intense exercise. Using transthoracic ultrasound Doppler at the level of the aortic valve, we compared blood flow velocities in the left ventricle and cardiac frequencies during rest and at 1, 3 and 4 min after a bout of exercise in 13 adult bottlenose dolphins (Tursiops truncatus, six male and seven female, body mass range 143-212 kg). Aortic cross-sectional area and ventricle blood velocity at the aortic valve were used to calculate SV, which together with fH provided estimates of left CO at rest and following exercise. fH and SV stabilized approximately 4-7 s following the post-respiratory tachycardia, so only data after the fH had stabilized were used for analysis and comparison. There were significant increases in fH, SV and CO associated with each breath. At rest, fH, SV and CO were uncorrelated with body mass, and averaged 41±9 beats min(-1), 136±19 ml and 5514±1182 l min(-1), respectively. One minute following high intensity exercise, the cardiac variables had increased by 104±43%, 63±11% and 234±84%, respectively. All variables remained significantly elevated in all animals for at least 4 min after the exercise. These baseline values provide the first data on SV and CO in awake and unrestrained cetaceans in water. PMID:26385334

  13. Cardiac output, oxygen consumption and arteriovenous oxygen difference following a sudden rise in exercise level in humans.

    PubMed Central

    De Cort, S C; Innes, J A; Barstow, T J; Guz, A

    1991-01-01

    1. To investigate the relative contributions of increases in cardiac output and arteriovenous oxygen difference to the increase in oxygen consumption during exercise, the ventilatory and cardiovascular responses to a sudden transition from unloaded cycling to 70 or 80 W were measured in six normal healthy subjects. 2. Oxygen consumption (VO2) was measured breath-by-breath and corrected for changes in lung gas stores. Cardiac output (Q) was measured beat-by-beat using pulsed Doppler ultrasound, and blood pressure was measured beat-by-beat using a non-invasive finger cuff (Finapres). All data were calculated off-line, second-by-second. 3. Arteriovenous oxygen difference (A-VO2) was calculated from Q and VO2 using the Fick Principle. Left ventricular afterload was calculated by dividing Q by mean blood pressure. 4. The data for Q and VO2 were closely fitted by single exponential curves (mean r2 0.84 and 0.90 respectively; r is the correlation coefficient). These curves yielded mean time constants for the increases in Q and VO2 of 28 and 55 s respectively following the increase in exercise level. In each individual subject, the time course of adjustment of Q was faster than that of VO2. There was a mean lag of 15 s from the start of the new exercise level before the derived A-V O2 began to increase; the mean time constant for A-V O2 was 57 s. 5. If A-V O2 had remained constant, the observed rise in Q alone would have resulted in an average of 87% of the increase in VO2 which was observed after 5 s. If Q had remained constant, the observed increase in A-V O2 would have led to only 8% of the actual increase in VO2 after 5 s. 6. Mean and systolic blood pressure rose and afterload fell immediately after the onset of the increased workload. The time constants of the systolic blood pressure and afterload responses to exercise varied widely and ranged from 37 to 81 and 10 to 26 s respectively (n = 4). 7. We conclude that Q is responsible for most of the early increase in VO2 following a sudden increase in exercise workload. Blood pressure responses to exercise are slower than Q and VO2 responses, probably due to the rapid decrease in afterload. 8. The dominant contribution of Q to adaptation to changing workload may be physiologically important particularly in heart disease, where decreased ability to increase cardiac output may limit the capacity to cope with changing metabolic needs during everyday activities. PMID:1816384

  14. Design and testing of an MRI-compatible cycle ergometer for non-invasive cardiac assessments during exercise

    PubMed Central

    2012-01-01

    Background Magnetic resonance imaging (MRI) is an important tool for cardiac research, and it is frequently used for resting cardiac assessments. However, research into non-pharmacological stress cardiac evaluation is limited. Methods We aimed to design a portable and relatively inexpensive MRI cycle ergometer capable of continuously measuring pedalling workload while patients exercise to maintain target heart rates. Results We constructed and tested an MRI-compatible cycle ergometer for a 1.5 T MRI scanner. Resting and sub-maximal exercise images (at 110 beats per minute) were successfully obtained in 8 healthy adults. Conclusions The MRI-compatible cycle ergometer constructed by our research group enabled cardiac assessments at fixed heart rates, while continuously recording power output by directly measuring pedal force and crank rotation. PMID:22423637

  15. Comparison of cardiac power output and exercise performance in patients with left ventricular assist devices, explanted (recovered) patients, and those with moderate to severe heart failure.

    PubMed

    Jakovljevic, Djordje G; George, Robert S; Donovan, Gay; Nunan, David; Henderson, Keiran; Bougard, Robert S; Yacoub, Magdi H; Birks, Emma J; Brodie, David A

    2010-06-15

    Peak cardiac power output (CPO), as a direct measurement of overall cardiac function, has been shown to be a most powerful predictor of prognosis for patients with chronic heart failure. The present study assessed CPO and exercise performance in patients implanted with a left ventricular assist device (LVAD), those explanted due to myocardial recovery, and those with moderate to severe heart failure. Hemodynamic and respiratory gas exchange measurements were undertaken at rest and at peak graded exercise. These were performed in 54 patients-20 with moderate to severe heart failure, 18 with implanted LVADs, and 16 with explanted LVADs. At rest there was a nonsignificant difference in CPO among groups (p >0.05). Peak CPO was significantly higher in the explanted LVAD than in the heart failure and implanted LVAD groups (heart failure 1.90 +/- 0.45 W, implanted LVAD 2.37 +/- 0.55 W, explanted LVAD 3.39 +/- 0.61 W, p <0.01) as was peak cardiac output (heart failure 9.1 +/- 2.1 L/min, implanted LVAD 12.4 +/- 2.2 L/min, explanted LVD 14.6 +/- 2.9 L/min, p <0.01). Peak oxygen consumption was higher in the explanted LVAD than in the heart failure and implanted LVAD groups (heart failure 15.8 +/- 4.1 ml/kg/min, implanted LVAD 19.8 +/- 5.8 ml/kg/min, explanted LVAD 28.2 +/- 5.0 ml/kg/min, p <0.05) as was anaerobic threshold (heart failure 11.2 +/- 1.9 ml/kg/min, implanted LVAD 14.7 +/- 4.9 ml/kg/min, explanted LVAD 21.4 +/- 5.0 ml/kg/min, p <0.05). In conclusion, peak CPO differentiates well during cardiac restoration using LVADs and emphasizes the benefits of this therapy. CPO has the potential to be a key physiologic marker of heart failure severity and can guide management of patients with LVAD. PMID:20538130

  16. The effect of intravenous epoprostenol (prostacyclin, PGI2) on cerebral blood flow and cardiac output in man.

    PubMed Central

    Cook, P J; Maidment, C G; Dandona, P; Hutton, R A; James, I M

    1983-01-01

    Epoprostenol (prostacyclin, PGI2) was given intravenously to seven healthy volunteers in a dose of 4 ng kg-1 min-1 over a 30 min period. Diastolic blood pressure fell but there was no change in cardiac output. The mean PGI2 concentration at the end of the infusion was 0.43 ng/ml (1.1 nM) and a significant inhibition of ADP-induced platelet aggregation occurred. Although obvious facial flushing occurred in all subjects and some subjects complained of headache, cerebral blood flow tended to fall. The results do not support the hypothesis that PGI2 acts as a physiological vasodilator involved in the homeostasis of normal cerebral blood flow. PMID:6362696

  17. Use of an extracorporeal arteriovenous tubing loop to measure cardiac output in intensive care unit patients by ultrasound velocity dilution.

    PubMed

    Eremenko, A; Balykov, I; Chaus, N; Kislukhin, V; Krivitski, N

    1998-01-01

    Thermodilution cardiac output (CO) measurement requires heart catheterization and is known as a risk factor. The existing cannula in the radial artery in intensive care unit (ICU) patients can be used to measure CO by ultrasound dilution (COus). An arteriovenous shunt between the radial artery and cubital vein was created using a 25 cm tubing loop. An ultrasound flow dilution sensor was clamped on the tubing and connected to a modified HD01 monitor (Transonic Systems, Inc., Ithaca, NY). Calibration injections of 1 ml 0.9% NaCl were injected into the tubing. An intravenous bolus injection consisted of 10-20 ml 0.9% NaCl. Simultaneously, CO was measured by thermal dilution (COth; MI 166A, Hewlett Packard, Andover, MA). Each value for COth or COus was based on the average of three to five injections. Blood flow through the shunt was 10 to 26 ml/min. The comparison was made on 14 patients. In 33 measurements, the regression equation was COth = -0.08 + 1.02 COus (r = 0.97). In 22 cases, the difference between COth and COus was less than 5%, in 9 cases it was in the range of 5-10%, and in 2 cases it was in the range of 10-20%. The presence of arterial and venous lines in an ICU setting obviates the need for cardiac catheterization for the determination of CO. PMID:9804473

  18. Assessment of cardiac sarcoidosis with advanced imaging modalities.

    PubMed

    Orii, Makoto; Imanishi, Toshio; Akasaka, Takashi

    2014-01-01

    Sarcoidosis is a chronic systemic disease of unknown etiology that is characterized by the presence of noncaseating epithelioid granulomas, usually in multiple organs. Several studies have shown that sarcoidosis might be the result of an exaggerated granulomatous reaction after exposure to unidentified antigens in genetically susceptible individuals. Cardiac involvement may occur and lead to an adverse outcome: the heart mechanics will be affected and that causes ventricular failure, and the cardiac electrical system will be disrupted and lead to third degree atrioventricular block, malignant ventricular tachycardia, and sudden cardiac death. Thus, early diagnosis and treatment of this potentially devastating disease is critically important. However, sensitive and accurate imaging modalities have not been established. Recent studies have demonstrated the promising potential of cardiac magnetic resonance imaging (MRI) and (18)F-fluoro-2-deoxyglucose positron emission tomography ((18)F-FDG PET) in the diagnosis and assessment of cardiac sarcoidosis (CS). In this review, we discuss the epidemiology, etiology, histological findings, and clinical features of sarcoidosis. We also introduce advanced imaging including (18)F-FDG PET and cardiac MRI as more reliable diagnostic modalities for CS. PMID:25250336

  19. Cardiac output by Doppler echocardiography in the premature baboon: Comparison with radiolabeled microspheres

    SciTech Connect

    Kinsella, J.P.; Morrow, W.R.; Gerstmann, D.R.; Taylor, A.F.; deLemos, R.A. )

    1991-04-01

    Pulsed-Doppler echocardiography (PDE) is a useful noninvasive method for determining left ventricular output (LVO). However, despite increasingly widespread use in neonatal intensive care units, validation studies in prematures with cardiopulmonary disease are lacking. The purpose of this study was to compare radiolabeled microsphere (RLM) and PDE measurements of LVO, using the critically ill premature baboon as a model of the human neonate. Twenty-two paired RLM and PDE measurements of LVO were obtained in 14 animals between 3 and 24 h of age. Average PDE LVO was 152 ml/min/kg (range, 40-258 ml/min/kg) compared to 158 ml/min/kg (range, 67-278 ml/min/kg) measured by RLM. Linear regression analysis of the paired measurements showed good correlation with a slope near unity (gamma = 0.94x + 4.20, r = 0.91, SEE = 25.7 ml). The authors conclude that PDE determinations of LVO compare well with those measured by RLM in the premature baboon. PDE appears to provide a valid estimate of LVO and should be useful in human prematures with cardiopulmonary distress.

  20. ECG patch monitors for assessment of cardiac rhythm abnormalities.

    PubMed

    Lobodzinski, S Suave

    2013-01-01

    The primary goal of long-term monitoring is the improvement of diagnostic yield. Despite the clear utility of Holter monitoring in clinical cardiology, issues of relatively low diagnostic yield, cost and inconvenience have motivated the development of ultra-portable devices referred to as ECG patch monitors. Although the "gold standard" for assessing cardiac rhythm abnormalities remains a 12-lead Holter, there is an increasing interest in portable monitoring devices that provide the opportunity for evaluating cardiac rhythm in real-world environments such as the workplace or home. To facilitate patient acceptance these monitors underwent a radical miniaturization and redesign to include wireless communication, water proofing and a patch carrier for attaching devices directly to the skin. We review recent developments in the field of "patch" devices primarily designed for very long-term monitoring of cardiac arrhythmic events. As the body of supporting clinical validation data grows, these devices hold promise for a variety of cardiac monitoring applications. From a clinical and research standpoint, the capacity to obtain longitudinal cardiac activity data by patch devices may have significant implications for device selection, monitoring duration, and care pathways for arrhythmia evaluation and atrial fibrillation surveillance. From a research standpoint, the new devices may allow for the development of novel diagnostic algorithms with the goal of finding patterns and correlations with exercise and drug regimens. PMID:24215754

  1. Role of cardiac output and the autonomic nervous system in the antinatriuretic response to acute constriction of the thoracic superior vena cava.

    NASA Technical Reports Server (NTRS)

    Schrier, R. W.; Humphreys, M. H.; Ufferman, R. C.

    1971-01-01

    Study of the differential characteristics of hepatic congestion and decreased cardiac output in terms of potential afferent stimuli in the antinatriuretic effect of acute thoracic inferior vena cava (TIVC) constriction. An attempt is made to see if the autonomic nervous system is involved in the antinatriuretic effect of acute TIVC or thoracic superior vena cava constriction.

  2. Differential acute effects of carbohydrate- and protein-rich drinks compared with water on cardiac output during rest and exercise in healthy young men.

    PubMed

    Rontoyanni, Victoria G; Werner, Kristin; Sanders, Thomas A B; Hall, Wendy L

    2015-08-01

    The acute effects of drinks rich in protein (PRO) versus carbohydrate (CHO) on cardiovascular hemodynamics and reactivity are uncertain. A randomized crossover design was used to compare 400-mL isoenergetic (1.1 MJ) drinks containing whey protein (PRO; 44 g) or carbohydrate (CHO; 57 g) versus 400 mL of water in 14 healthy men. The primary and secondary outcomes were changes in cardiac output, blood pressure, systemic vascular resistance (SVR) and digital volume pulse measured prior to and 30 min following consumption at rest, during 12 min of multi-stage bicycle ergometry, and 15 min postexercise. The mean change (95% confidence interval (CI)) in resting cardiac output at 30 min was greater for CHO than for PRO or water: 0.7 (0.4 to 1.0), 0.1 (-0.2 to 0.40), and 0.0 (-0.3 to 0.3) L/min (P < 0.001), respectively; the higher cardiac output following CHO was accompanied by an increase in stroke volume and a lower SVR. The mean increments (95% CI) in cardiac output during exercise were CHO 4.7 (4.4 to 5.0), PRO 4.9 (4.6 to 5.2), and water 4.6 (4.3 to 4.9) L/min with the difference between PRO versus water being significant (P < 0.025). There were no other statistically significant differences. In summary, a CHO-rich drink increased cardiac output and lowered SVR in the resting state compared with a PRO-rich drink or water but the effect size of changes in these variables did not differ during or after exercise between CHO and PRO. Neither protein nor carbohydrate affected blood pressure reactivity to exercise. PMID:26244599

  3. Diesel Exhaust Inhalation Increases Cardiac Output, Bradyarrhythmias, and Parasympathetic Tone in Aged Heart Failure-Prone Rats

    EPA Science Inventory

    Acute air pollutant inhalation is linked to adverse cardiac events and death, and hospitalizations for heart failure. Diesel exhaust (DE) is a major air pollutant suspected to exacerbate preexisting cardiac conditions, in part, through autonomic and electrophysiologic disturbance...

  4. Comparison of cardiac output of the left and right side of the heart by ultrafast computed tomography

    SciTech Connect

    Wolfkiel, C.J.; Ferguson, J.L.; Law, W.R.; Chomka, E.V.; Brundage, B.H.

    1986-03-05

    Ultrafast computed tomography (CT) evaluation of cardiac output (CO) can be determined using indicator dilution theory. The concentration of an iodinated contrast agent injected into a vein of a subject can be measured as a function of time by serial EKG, gated CT imaging. The contrast density of the blood pool measured by CT defines the indicator concentration. CT CO is proportional to the area under a time density curve from a region of the blood pool. Proper subject position and scanning timing allows CT to measure CO in the pulmonary (PA) artery and the aorta (AO) with the same contrast bolus. Three anesthetized dogs were multiply scanned following simultaneous injections of contrast and radioactive tracer microspheres. Microsphere CO was determined by reference withdrawal method. Multiple thermodilution CO measurements were made just prior and after each CT CO procedure. 24 comparisons were made of thermodilution, microsphere and CT CO measured in the PA (right sided CO (RSCO)) and the AO (left sided CO (LSCO)). CT CO was calculated as the ratio of the volume of contrast injected to the time density curve area corrected for the relation of contrast density to CT number. RSCO agreed very closely to LSCO (r = .99, p < .001; y = 1.0x +/- .32). RSCO correlated to thermodilution (r = .96, p < .001; y = 1.2x +/- 1.3) and microsphere CO (r = .93, p < .001; y = .69x +/- 1.3). These data show that CT CO measurements can be made in the PA and AO with equal accuracy.

  5. Accuracy of cardiac output measurements during off-pump coronary artery bypass grafting: according to the vessel anastomosis sites

    PubMed Central

    Park, Sung Yong; Kim, Dae Hee; Joe, Han Bum; Yoo, Ji Young; Kim, Jin Soo; Kang, Min

    2012-01-01

    Background During beating heart surgery, the accuracy of cardiac output (CO) measurement techniques may be influenced by several factors. This study was conducted to analyze the clinical agreement among stat CO mode (SCO), continuous CO mode (CCO), arterial pressure waveform-based CO estimation (APCO), and transesophageal Doppler ultrasound technique (UCCO) according to the vessel anastomosis sites. Methods This study was prospectively performed in 25 patients who would be undergoing elective OPCAB. Hemodynamic variables were recorded at the following time points: during left anterior descending (LAD) anastomosis at 1 min and 5 min; during obtuse marginal (OM) anastomosis at 1 min and 5 min: and during right coronary artery (RCA) anastomosis at 1 min and 5 min. The variables measured including the SCO, CCO, APCO, and UCCO. Results CO measurement techniques showed different correlations according to vessel anastomosis site. However, the percent error observed was higher than the value of 30% postulated by the criteria of Critchley and Critchley during all study periods for all CO measurement techniques. Conclusions In the beating heart procedure, SCO, CCO and APCO showed different correlations according to the vessel anastomosis sites and did not agree with UCCO. CO values from the various measurement techniques should be interpreted with caution during OPCAB. PMID:22679538

  6. Estimation of cardiac output and systemic vascular resistance using a multivariate regression model with features selected from the finger photoplethysmogram and routine cardiovascular measurements

    PubMed Central

    2013-01-01

    Background Cardiac output (CO) and systemic vascular resistance (SVR) are two important parameters of the cardiovascular system. The ability to measure these parameters continuously and noninvasively may assist in diagnosing and monitoring patients with suspected cardiovascular diseases, or other critical illnesses. In this study, a method is proposed to estimate both the CO and SVR of a heterogeneous cohort of intensive care unit patients (N=48). Methods Spectral and morphological features were extracted from the finger photoplethysmogram, and added to heart rate and mean arterial pressure as input features to a multivariate regression model to estimate CO and SVR. A stepwise feature search algorithm was employed to select statistically significant features. Leave-one-out cross validation was used to assess the generalized model performance. The degree of agreement between the estimation method and the gold standard was assessed using Bland-Altman analysis. Results The Bland-Altman bias precision (1.96 times standard deviation) for CO was -0.01 2.70 L min-1 when only photoplethysmogram (PPG) features were used, and for SVR was -0.87 412 dyn.s.cm-5 when only one PPG variability feature was used. Conclusions These promising results indicate the feasibility of using the method described as a non-invasive preliminary diagnostic tool in supervised or unsupervised clinical settings. PMID:23452705

  7. Downscaling climate model output for water resources impacts assessment (Invited)

    NASA Astrophysics Data System (ADS)

    Maurer, E. P.; Pierce, D. W.; Cayan, D. R.

    2013-12-01

    Water agencies in the U.S. and around the globe are beginning to wrap climate change projections into their planning procedures, recognizing that ongoing human-induced changes to hydrology can affect water management in significant ways. Future hydrology changes are derived using global climate model (GCM) projections, though their output is at a spatial scale that is too coarse to meet the needs of those concerned with local and regional impacts. Those investigating local impacts have employed a range of techniques for downscaling, the process of translating GCM output to a more locally-relevant spatial scale. Recent projects have produced libraries of publicly-available downscaled climate projections, enabling managers, researchers and others to focus on impacts studies, drawing from a shared pool of fine-scale climate data. Besides the obvious advantage to data users, who no longer need to develop expertise in downscaling prior to examining impacts, the use of the downscaled data by hundreds of people has allowed a crowdsourcing approach to examining the data. The wide variety of applications employed by different users has revealed characteristics not discovered during the initial data set production. This has led to a deeper look at the downscaling methods, including the assumptions and effect of bias correction of GCM output. Here new findings are presented related to the assumption of stationarity in the relationships between large- and fine-scale climate, as well as the impact of quantile mapping bias correction on precipitation trends. The validity of these assumptions can influence the interpretations of impacts studies using data derived using these standard statistical methods and help point the way to improved methods.

  8. Rapid assessment of cardiac contractility on a home bathroom scale.

    PubMed

    Etemadi, Mozziyar; Inan, Omer T; Giovangrandi, Laurent; Kovacs, Gregory T A

    2011-11-01

    Analyzing systolic time intervals-specifically the preejection-period (PEP)-is widely accepted as one of the few methods for the noninvasive assessment of cardiac contractility. In this paper, we investigated the ballistocardiogram (BCG) as a way to noninvasively measure myocardial contractility when combined with the ECG. Specifically, we derived a parameter from the BCG and ECG that we hypothesized would be highly correlated to PEP. This is the time delay between the J-wave peak of the BCG and the R-wave of the ECG, which we refer to as the RJ interval. The RJ interval was correlated to PEP (r(2) = 0.86) for 2126 heartbeats across ten subjects, with a y-intercept of 138 ms and slope of 1.05. This suggests that the RJ interval can be reliably used as a noninvasive assessment of cardiac contractility. PMID:21843998

  9. Respirometric Oxidative Phosphorylation Assessment in Saponin-permeabilized Cardiac Fibers

    PubMed Central

    Hughey, Curtis C.; Hittel, Dustin S.; Johnsen, Virginia L.; Shearer, Jane

    2011-01-01

    Investigation of mitochondrial function represents an important parameter of cardiac physiology as mitochondria are involved in energy metabolism, oxidative stress, apoptosis, aging, mitochondrial encephalomyopathies and drug toxicity. Given this, technologies to measure cardiac mitochondrial function are in demand. One technique that employs an integrative approach to measure mitochondrial function is respirometric oxidative phosphorylation (OXPHOS) analysis. The principle of respirometric OXPHOS assessment is centered around measuring oxygen concentration utilizing a Clark electrode. As the permeabilized fiber bundle consumes oxygen, oxygen concentration in the closed chamber declines. Using selected substrate-inhibitor-uncoupler titration protocols, electrons are provided to specific sites of the electron transport chain, allowing evaluation of mitochondrial function. Prior to respirometric analysis of mitochondrial function, mechanical and chemical preparatory techniques are utilized to permeabilize the sarcolemma of muscle fibers. Chemical permeabilization employs saponin to selectively perforate the cell membrane while maintaining cellular architecture. This paper thoroughly describes the steps involved in preparing saponin-skinned cardiac fibers for oxygen consumption measurements to evaluate mitochondrial OXPHOS. Additionally, troubleshooting advice as well as specific substrates, inhibitors and uncouplers that may be used to determine mitochondria function at specific sites of the electron transport chain are provided. Importantly, the described protocol may be easily applied to cardiac and skeletal tissue of various animal models and human samples. PMID:21403632

  10. Ultrasound cardiac output units.

    PubMed

    1988-01-01

    We evaluated 2 dedicated CO US units that calculate CO for teenage and adult ranges. We also tested a unit designed for use on neonatal to pediatric patients and discussed this device separately. Because of the limitations of US technology, we found these units to be best suited for trending CO; however, the utility of US CO for this application far outweighs its limitations. PMID:3079193

  11. Ultrasound cardiac output units.

    PubMed

    1988-12-01

    We evaluated two dedicated units that calculate CO for teenage and adult ranges. We also tested a unit designed for use on neonatal to pediatric patients and discussed this device separately. Both of the evaluated units were rated Acceptable. Because of the limitations of ultrasound (US) technology, we found these units to be best suited for trending CO; however, the utility of US CO for this application far outweighs its limitations. PMID:3273933

  12. Chronic reduction in cardiac output induces hypoxic signaling in larval zebrafish even at a time when convective oxygen transport is not required.

    PubMed

    Kopp, Renate; Schwerte, Thorsten; Egg, Margit; Sandbichler, Adolf Michael; Egger, Bernhard; Pelster, Bernd

    2010-09-01

    In the present study, the zebrafish breakdance mutant (bre) was used to assess the role of blood flow in development because it has been previously shown that bre larvae have a chronically reduced cardiac output as a result of ventricular contraction following only every second atrial contraction in addition to an atrial bradycardia. We confirmed a 50% reduction compared with control fish and further showed that blood flow in the caudal part of the dorsal aorta decreased by 80%. Associated with these reductions in blood flow were indications of developmental retardation in bre mutants, specifically delayed hatching, reduced cell proliferation, and a transiently decreased growth rate. Surprisingly, an increased red blood cell concentration and an earlier appearance of trunk vessels in bre larvae indicated some compensation to convective oxygen transport, although in previous studies it has been shown that zebrafish larvae at this stage obtain oxygen by bulk diffusion. In bre animals immunohistochemical analyses showed a significant increase in hypoxia inducible factor 1 (HIF)-? protein expression, comparable with wild-type larvae that were raised under hypoxic conditions. Accordingly, the expression of some hif downstream genes was affected. Furthermore, Affymetrix microarray analyses revealed a large number of genes that were differently expressed comparing control and bre larvae, and the number even increased with proceeding development. The results showed that a chronic reduction in blood flow generated hypoxic molecular signals despite partial compensation by increased oxygen carrying capacity and transiently slowed the overall development of zebrafish bre larvae. PMID:20571107

  13. PKPD modelling of the interrelationship between mean arterial BP, cardiac output and total peripheral resistance in conscious rats

    PubMed Central

    Snelder, N; Ploeger, B A; Luttringer, O; Rigel, D F; Webb, R L; Feldman, D; Fu, F; Beil, M; Jin, L; Stanski, D R; Danhof, M

    2013-01-01

    Background and Purpose The homeostatic control of arterial BP is well understood with changes in BP resulting from changes in cardiac output (CO) and/or total peripheral resistance (TPR). A mechanism-based and quantitative analysis of drug effects on this interrelationship could provide a basis for the prediction of drug effects on BP. Hence, we aimed to develop a mechanism-based pharmacokinetic-pharmacodynamic (PKPD) model in rats that could be used to characterize the effects of cardiovascular drugs with different mechanisms of action (MoA) on the interrelationship between BP, CO and TPR. Experimental Approach The cardiovascular effects of six drugs with diverse MoA, (amlodipine, fasudil, enalapril, propranolol, hydrochlorothiazide and prazosin) were characterized in spontaneously hypertensive rats. The rats were chronically instrumented with ascending aortic flow probes and/or aortic catheters/radiotransmitters for continuous recording of CO and/or BP. Data were analysed in conjunction with independent information on the time course of drug concentration using a mechanism-based PKPD modelling approach. Key Results By simultaneous analysis of the effects of six different compounds, the dynamics of the interrelationship between BP, CO and TPR were quantified. System-specific parameters could be distinguished from drug-specific parameters indicating that the model developed is drug-independent. Conclusions and Implications A system-specific model characterizing the interrelationship between BP, CO and TPR was obtained, which can be used to quantify and predict the cardiovascular effects of a drug and to elucidate the MoA for novel compounds. Ultimately, the proposed PKPD model could be used to predict the effects of a particular drug on BP in humans based on preclinical data. PMID:23849040

  14. Drug effects on the CVS in conscious rats: separating cardiac output into heart rate and stroke volume using PKPD modelling

    PubMed Central

    Snelder, N; Ploeger, B A; Luttringer, O; Rigel, D F; Fu, F; Beil, M; Stanski, D R; Danhof, M

    2014-01-01

    Background and Purpose Previously, a systems pharmacology model was developed characterizing drug effects on the interrelationship between mean arterial pressure (MAP), cardiac output (CO) and total peripheral resistance (TPR). The present investigation aims to (i) extend the previously developed model by parsing CO into heart rate (HR) and stroke volume (SV) and (ii) evaluate if the mechanism of action (MoA) of new compounds can be elucidated using only HR and MAP measurements. Experimental Approach Cardiovascular effects of eight drugs with diverse MoAs (amiloride, amlodipine, atropine, enalapril, fasudil, hydrochlorothiazide, prazosin and propranolol) were characterized in spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto (WKY) rats following single administrations of a range of doses. Rats were instrumented with ascending aortic flow probes and aortic catheters/radiotransmitters for continuous recording of MAP, HR and CO throughout the experiments. Data were analysed in conjunction with independent information on the time course of the drug concentration following a mechanism-based pharmacokinetic-pharmacodynamic modelling approach. Key Results The extended model, which quantified changes in TPR, HR and SV with negative feedback through MAP, adequately described the cardiovascular effects of the drugs while accounting for circadian variations and handling effects. Conclusions and Implications A systems pharmacology model characterizing the interrelationship between MAP, CO, HR, SV and TPR was obtained in hypertensive and normotensive rats. This extended model can quantify dynamic changes in the CVS and elucidate the MoA for novel compounds, with one site of action, using only HR and MAP measurements. Whether the model can be applied for compounds with a more complex MoA remains to be established. PMID:24962208

  15. Finger arterial versus intrabrachial pressure and continuous cardiac output during head-up tilt testing in healthy subjects.

    PubMed

    Jellema, W T; Imholz, B P; van Goudoever, J; Wesseling, K H; van Lieshout, J J

    1996-08-01

    1. The aims of this study were to determine the clinical feasibility of continuous, non-invasive Finapres recordings as a replacement for intrabrachial pressure during a 30 min head-up tilt, and the reliability of continuous cardiac output computation by pulse contour analysis from the finger arterial versus the brachial waveform. 2. In eight healthy subjects a 30 min 70 degrees passive head-up tilt was performed. Finger arterial (FINAP) and intrabrachial (IAP) pressures were measured simultaneously. Beat-to-beat changes in stroke volume were computed using a pulse contour algorithm. 3. Accuracy (the group-averaged FINAP-IAP difference) and precision (the SD of the difference) of Finapres measurements were 4 and 9 mmHg for systolic blood pressure, -5 and 9 mmHg for mean blood pressure and -5 and 9mmHg for diastolic blood pressure. 4. The time course of the FINAP-IAP differences during head-up tilt showed a linear trend (P < 0.001 for all pressure levels). Averaged for the group, the difference increased 7 mmHg for mean blood pressure. The difference in stroke volume computed from FINAP and IAP was 0.3 +/- 5% (mean +/- SD), and independent of the duration of the tilt (P > 0.05). This difference did not change at low blood pressure levels (0.5 +/- 6%). 5. The qualitative performance of the Finapres allows it to be used in the clinical setting as a monitor of sudden changes in blood pressure induced by a 30 min head-up tilt. Relative changes in stroke volume, as obtained by pulse contour analysis of the finger arterial waveform, closely follow intrabrachial values during long-duration head-up tilt and associated arterial hypotension. PMID:8795443

  16. CARDIO--a Lotus 1-2-3 based computer program for rapid calculation of cardiac output from dye or thermal dilution curves.

    PubMed

    Brill, R W; Bushnell, P G

    1989-01-01

    We have developed a menu-driven computer program (CARDIO), based on a Lotus 1-2-3 template and a series of macrocommands, that rapidly and semiautomatically calculates cardiac output from dye or thermal dilution curves. CARDIO works with any dye or thermal dilution recorder with an analog output, any analog to digital (A-to-D) conversion system, and any computer capable of running Lotus 1-2-3 version 2. No prior experience with Lotus 1-2-3 is needed to operate CARDIO, but experienced users can take full advantage of Lotus 1-2-3's graphics, data manipulation, and data retrieval capabilities. PMID:2689079

  17. Early predictors of acute kidney injury in patients with cirrhosis and bacterial infection: urinary neutrophil gelatinase-associated lipocalin and cardiac output as reliable tools

    PubMed Central

    Ximenes, Rafael O.; Farias, Alberto Q.; Helou, Claudia M.B.

    2015-01-01

    Background Hemodynamic abnormalities and acute kidney injury (AKI) are often present in infected cirrhotic patients. Hence, an early diagnosis of AKI is necessary, which might require the validation of new predictors as the determinations of urinary neutrophil gelatinase-associated lipocalin (uNGAL) and cardiac output. Methods We evaluated 18 infected cirrhotic patients subdivided into two groups at admission (0 hours). In Group I, we collected urine samples at 0 hours, 6 hours, 24 hours, and 48 hours for uNGAL and fractional excretion of sodium determinations. In Group II, we measured cardiac output using echocardiography. Results The age of patients was 55.0±1.9 years, and 11 patients were males. The Model for End-Stage Liver Disease score was 21±1, whereas the Child–Pugh score was C in 11 patients and B in 7 patients. Both patients in Group I and Group II showed similar baseline characteristics. In Group I, we diagnosed AKI in 5 of 9 patients, and the mean time to this diagnosis by measuring serum creatinine was 5.4 days. Patients with AKI showed higher uNGAL levels than those without AKI from 6 hours to 48 hours. The best accuracy using the cutoff values of 68 ng uNGAL/mg creatinine was achieved at 48 hours when we distinguished patients with and without AKI in all cases. In Group II, we diagnosed AKI in 4 of 9 patients, and cardiac output was significantly higher in patients who developed AKI at 0 hours. Conclusion Both uNGAL and cardiac output determinations allow the prediction of AKI in infected cirrhotic patients earlier than increments in serum creatinine. PMID:26484038

  18. Modifications to the accuracy assessment analysis routine MLTCRP to produce an output file

    NASA Technical Reports Server (NTRS)

    Carnes, J. G.

    1978-01-01

    Modifications are described that were made to the analysis program MLTCRP in the accuracy assessment software system to produce a disk output file. The output files produced by this modified program are used to aggregate data for regions greater than a single segment.

  19. Pharmacokinetics, hemodynamic and metabolic effects of epinephrine to prevent post-operative low cardiac output syndrome in children

    PubMed Central

    2014-01-01

    Introduction The response to exogenous epinephrine (Ep) is difficult to predict given the multitude of factors involved such as broad pharmacokinetic and pharmacodynamic between-subject variabilities, which may be more pronounced in children. We investigated the pharmacokinetics and pharmacodynamics of Ep, co-administered with milrinone, in children who underwent open heart surgical repair for congenital defects following cardiopulmonary bypass, including associated variability factors. Methods Thirty-nine children with a high risk of low cardiac output syndrome were prospectively enrolled. Ep pharmacokinetics, hemodynamic and metabolic effects were analyzed using the non-linear mixed effects modeling software MONOLIX. According to the final model, an Ep dosing simulation was suggested. Results Ep dosing infusions ranged from 0.01 to 0.23 μg.kg-1.min-1 in children whose weight ranged from 2.5 to 58 kg. A one-compartment open model with linear elimination adequately described the Ep concentration-time courses. Bodyweight (BW) was the main covariate influencing clearance (CL) and endogenous Ep production rate (q0) via an allometric relationship: CL(BWi) = θCL x (BWi)3/4 and q0(BWi) = θq0 x (BWi )3/4. The increase in heart rate (HR) and mean arterial pressure (MAP) as a function of Ep concentration were well described using an Emax model. The effect of age was significant on HR and MAP basal level parameters. Assuming that Ep stimulated the production rate of plasma glucose, the increases in plasma glucose and lactate levels were well described by turnover models without any significant effect of age, BW or exogenous glucose supply. Conclusions According to this population analysis, the developmental effects of BW and age explained a part of the pharmacokinetic and pharmacodynamics between-subject variabilities of Ep administration in critically ill children. This approach ultimately leads to a valuable Ep dosing simulation which should help clinicians to determine an appropriate a priori dosing regimen. PMID:24456639

  20. Assessing the Habitability and the Biogeochemical Output of Subsurface Biomes

    NASA Astrophysics Data System (ADS)

    Schrenk, M.; Seager, S.

    2007-12-01

    The subsurface microbial biosphere has been estimated to represent the largest biome on Earth in terms of sheer volume of habitable space. Even if the magnitude of the subsurface biosphere is vastly overestimated, it could still represent a significant reservoir of nutrients, and harbor yet-to-be-discovered metabolic and physiological diversity. Subsurface environments have also been evoked as some of the most likely sites for extraterrestrial life as they are sheltered from harsh surface conditions, may retain liquid water, and may be linked to geothermal and geochemical energy sources. Despite the recognized importance of these environments, relatively little is known about factors constraining the habitability of subsurface ecosystems, or how these factors influence life detection through either in situ or remote measurements. We present a two part model in which we evaluate the habitability of subsurface environments based upon the physiological characteristics of specific metabolic groups of microorganisms (e.g. methanogens, sulfate reducers, etc.) then assess the potential for detection of their biosignatures through both direct and remote measurements. Easily parameterized values such as temperature, pressure, and pore space will be compared with free energy fluxes derived from models of subsurface environments. These data will be used to determine the rates, character, and magnitude of biosignatures produced. Since local influences such as the spatial and temporal scales of habitable niches may have important consequences for life, these factors will be evaluated. The geometry and composition of host materials will also be incorporated into the models, as this may either dampen, or record evidence of biological activities. This research provides a key framework for testing hypotheses based upon on observational data on Earth, and may lead to new insights into prospecting for life in subsurface environments on Mars, Europa, and rocky extrasolar planets.

  1. Quantitative automated assessment of myocardial perfusion at cardiac catheterization.

    PubMed

    Boyle, Andrew J; Schuleri, Karl H; Lienard, Jean; Vaillant, Regis; Chan, Michael Y; Zimmet, Jeffrey M; Mazhari, Ramesh; Centola, Marco; Feigenbaum, Gary; Dib, Joud; Kapur, Navin K; Hare, Joshua M; Resar, Jon R

    2008-10-15

    Perfusion assessed in the cardiac catheterization laboratory predicts outcomes after myocardial infarction. The aim of this study was to investigate a novel method of assessing perfusion using digital subtraction angiography to generate a time-density curve (TDC) of myocardial blush, incorporating epicardial and myocardial perfusion. Seven pigs underwent temporary occlusion of the left anterior descending coronary artery for 60 minutes. Angiography was performed in the same projections before, during, and after occlusion. Perfusion parameters were obtained from the TDC and compared with Thrombolysis In Myocardial Infarction (TIMI) frame count and myocardial perfusion grade. In addition, safety and feasibility were tested in 8 patients after primary percutaneous coronary intervention. The contrast density differential between the proximal artery and the myocardium derived from the TDC correlated well with TIMI myocardial perfusion grade (R = 0.54, p <0.001). The arterial transit time derived from the TDC correlated with TIMI frame count (R = 0.435, p = 0.011). Using a cutoff of 2.4, the density/time ratio, a ratio of density differential to transit time, had sensitivity and specificity of 100% for coronary arterial occlusion. The positive and negative predictive values were 100%. The generation of a TDC was safe and feasible in 7 patients after acute myocardial infarctions, but the correlation between TDC-derived parameters and TIMI parameters did not reach statistical significance. In conclusion, this novel method of digital subtraction angiography with rapid, automated, quantitative assessment of myocardial perfusion in the cardiac catheterization laboratory correlates well with established angiographic measures of perfusion. Further studies to assess the prognostic value of this technique are warranted. PMID:18929697

  2. Automatic Assessment of Socioeconomic Impact on Cardiac Rehabilitation

    PubMed Central

    Calvo, Mireia; Subirats, Laia; Ceccaroni, Luigi; Maroto, José María; de Pablo, Carmen; Miralles, Felip

    2013-01-01

    Disability-Adjusted Life Years (DALYs) and Quality-Adjusted Life Years (QALYs), which capture life expectancy and quality of the remaining life-years, are applied in a new method to measure socioeconomic impacts related to health. A 7-step methodology estimating the impact of health interventions based on DALYs, QALYs and functioning changes is presented. It relates the latter (1) to the EQ-5D-5L questionnaire (2) to automatically calculate the health status before and after the intervention (3). This change of status is represented as a change in quality of life when calculating QALYs gained due to the intervention (4). In order to make an economic assessment, QALYs gained are converted to DALYs averted (5). Then, by inferring the cost/DALY from the cost associated to the disability in terms of DALYs lost (6) and taking into account the cost of the action, cost savings due to the intervention are calculated (7) as an objective measure of socioeconomic impact. The methodology is implemented in Java. Cases within the framework of cardiac rehabilitation processes are analyzed and the calculations are based on 200 patients who underwent different cardiac-rehabilitation processes. Results show that these interventions result, on average, in a gain in QALYs of 0.6 and a cost savings of 8,000 €. PMID:24284349

  3. Noninvasive cardiac output determined with a new method based on gas exchange measurements and carbon dioxide rebreathing: a study in animals/pigs.

    PubMed

    Gedeon, A; Krill, P; Kristensen, J; Gottlieb, I

    1992-10-01

    A system has been designed to determine cardiac output noninvasively. The system's main component is a closed breathing circuit and it measures oxygen uptake (VO2), carbon dioxide elimination (VCO2), and end-tidal CO2 partial pressure (PET). As an integral part of the system, periods of CO2 rebreathing can be automatically implemented. The CO2 partial pressure of oxygenated mixed venous blood (Pv) is obtained from the measured exponential rise of the PET value during such a CO2 rebreathing maneuver. A new method is described for estimating the pulmonary blood flow, alveolar ventilation, cardiac output (CO), and mixed venous oxygen saturation (SVO2) from PV, PET, VO2, VCO2, tidal volume, and arterial oxygen saturation. The method was evaluated in 6 anesthetized and mechanically ventilated pigs. A wide range of cardiac output, shunt fractions, and dead space to tidal volume ratios were induced by combinations of bronchoalveolar lavage, hypervolemia, hypovolemia, and variable levels of positive end-expiratory pressure (PEEP). The bias between the CO obtained with the noninvasive technique (CO L/min) and the thermodilution CO (Qt L/min) was 0.13 L/min (SD = 0.78 L/min) and the correlation was N = 64; R = 0.92; CO = 0.95*Qt + 0.38. The bias obtained for double determinations with the noninvasive CO technique was 0.3 L/min (SD = 0.5 L/min). The bias between the noninvasive estimates of Svo2 and the directly measured values was 1.1% (SD = 9.3%). For double determination with the noninvasive technique the bias was -0.9% (SD = 4.7%). It is concluded that in mechanically ventilated pigs the proposed method produces good estimates of CO and SVO2 also in the presence of significant ventilation/perfusion mismatch. PMID:1453186

  4. Hemodynamic assessment of indomethacin-induced fetal heart failure in high-output state.

    PubMed

    Tongsong, Theera; Luewan, Suchaya; Srisupundit, Kasemsri; Jatavan, Thanate

    2013-09-01

    Hemodynamic study was performed on a 32-year-old woman presenting at 27 weeks' gestation. Ultrasound revealed a single normal fetus with mild cardiomegaly, polyhydramnios, and placental chorioangioma. Doppler study showed increased middle cerebral artery peak systolic velocity, normal Tei index, and forward flow of "a" wave with normal preload in the ductus venosus. Twelve hours after initiation of indomethacin for tocolysis, frank hydrops fetalis developed rapidly. The right ventricle showed poor contractility and performance. Markedly increased preload in ductus venosus with reversed "a" wave and pulsations in the umbilical vein were demonstrated. This study suggests that indomepacin treatment in fetal high-cardiac output state should be used with extreme caution. PMID:23712591

  5. Economic Input-Output Life Cycle Assessment of Water Reuse Strategies in Residential Buildings

    EPA Science Inventory

    This paper evaluates the environmental sustainability and economic feasibility of four water reuse designs through economic input-output life cycle assessments (EIO-LCA) and benefit/cost analyses. The water reuse designs include: 1. Simple Greywater Reuse System for Landscape Ir...

  6. Comparison of general circulation model outputs and ensemble assessment of climate change using a Bayesian approach

    NASA Astrophysics Data System (ADS)

    Huang, Yongtai

    2014-11-01

    A number of general circulation models (GCMs) have been developed to project future global climate change. Unfortunately, projected results are different and it is not known which set of GCM outputs are more creditable than the others. The objective of this work is to present a Bayesian approach to compare GCM outputs and make an ensemble assessment of climate change. This method is applied to Cannonsville Reservoir watershed, New York, USA. The GCM outputs under the 20C3M scenario for a historical time period of 1981-2000 are used to calculate posterior probabilities, and the outputs under the scenarios (A1B, A2 and B1) for the future time period of 2084-2100 are then processed using the Bayesian modeling averaging (BMA) which is a statistical procedure that infers a consensus prediction by weighing individual predictions based on the posterior probabilities, with the better performing predictions receiving higher weights. The obtained results reveal that the posterior probabilities are slightly different for four variables including average, maximum and minimum temperatures, and shortwave radiation, implying that the GCM outputs are qualitatively different for these four variables, but the distributions of posterior probabilities are flat for precipitation and wind speed, suggesting that the GCM outputs are qualitatively similar for these two variables. The results also show that no one set of GCM data are the best for all six meteorological variables. Furthermore, the results indicate that the projected changes are for regional warming, but the changes in precipitation, wind speed, and shortwave radiation depend on the emission scenarios and seasons. The application of the method demonstrates that the Bayesian approach is useful for the comparison of GCM outputs and making ensemble assessments of climate change.

  7. Perspectives to Performance of Environment and Health Assessments and Models—From Outputs to Outcomes?

    PubMed Central

    Pohjola, Mikko V.; Pohjola, Pasi; Tainio, Marko; Tuomisto, Jouni T.

    2013-01-01

    The calls for knowledge-based policy and policy-relevant research invoke a need to evaluate and manage environment and health assessments and models according to their societal outcomes. This review explores how well the existing approaches to assessment and model performance serve this need. The perspectives to assessment and model performance in the scientific literature can be called: (1) quality assurance/control, (2) uncertainty analysis, (3) technical assessment of models, (4) effectiveness and (5) other perspectives, according to what is primarily seen to constitute the goodness of assessments and models. The categorization is not strict and methods, tools and frameworks in different perspectives may overlap. However, altogether it seems that most approaches to assessment and model performance are relatively narrow in their scope. The focus in most approaches is on the outputs and making of assessments and models. Practical application of the outputs and the consequential outcomes are often left unaddressed. It appears that more comprehensive approaches that combine the essential characteristics of different perspectives are needed. This necessitates a better account of the mechanisms of collective knowledge creation and the relations between knowledge and practical action. Some new approaches to assessment, modeling and their evaluation and management span the chain from knowledge creation to societal outcomes, but the complexity of evaluating societal outcomes remains a challenge. PMID:23803642

  8. Realtime Automatic Assessment of Cardiac Function in Echocardiography.

    PubMed

    Storve, Sigurd; Grue, Jahn Frederik; Samstad, Stein; Dalen, Havard; Haugen, Bjorn Olav; Torp, Hans

    2016-03-01

    Assessment of cardiac function by echocardiography is challenging for nonexperts. In a patient with dyspnea, quantification of the mitral annular excursion (MAE) and velocities is important for the diagnosis of heart failure. The displacement of the atrioventricular (AV) plane is a good indicator of systolic left ventricular function, while the peak velocities give supplementary information about the systolic and diastolic function. By measuring these parameters automatically, a preliminary diagnosis can be given by the nonexpert. We propose an automatic algorithm to localize the mitral annular points in an apical four-chamber view and estimate the MAE, as well as the systolic, early diastolic, and late diastolic tissue peak velocities, by using a deformable ventricle model for orientation and tissue Doppler data for tracking. Automatic parameter estimates from 367 tissue Doppler recordings were compared to reference measurements by experienced cardiologists to assess the accuracy of the estimation, as well as the ability to correctly detect reduced MAE, which we defined as less than 10 mm. The dataset consisted of 200 recordings from a patient population and 167 healthy from a population study. When considering the average of the septal and lateral values, the estimation error for the MAE had a standard deviation of 2.1 mm, which was reduced to 1.9 mm when excluding recordings for which the automatic segmentation failed to locate the AV plane (41 recordings). The corresponding standard deviations for the peak velocities were around 1 cm/s. The classification of MAE was correct in 90% of the cases and had a sensitivity of 83% and a specificity of 92%. We conclude that the algorithm has good accuracy and note that the estimation error for the MAE was comparable to interobserver and methodology agreements reported in the literature. PMID:26780792

  9. Continuous cardiac output and left atrial pressure monitoring by long time interval analysis of the pulmonary artery pressure waveform: proof of concept in dogs.

    PubMed

    Xu, Da; Olivier, N Bari; Mukkamala, Ramakrishna

    2009-02-01

    We developed a technique to continuously (i.e., automatically) monitor cardiac output (CO) and left atrial pressure (LAP) by mathematical analysis of the pulmonary artery pressure (PAP) waveform. The technique is unique to the few previous related techniques in that it jointly estimates the two hemodynamic variables and analyzes the PAP waveform over time scales greater than a cardiac cycle wherein wave reflections and inertial effects cease to be major factors. First, a 6-min PAP waveform segment is analyzed so as to determine the pure exponential decay and equilibrium pressure that would eventually result if cardiac activity suddenly ceased (i.e., after the confounding wave reflections and inertial effects vanish). Then, the time constant of this exponential decay is computed and assumed to be proportional to the average pulmonary arterial resistance according to a Windkessel model, while the equilibrium pressure is regarded as average LAP. Finally, average proportional CO is determined similar to invoking Ohm's law and readily calibrated with one thermodilution measurement. To evaluate the technique, we performed experiments in five dogs in which the PAP waveform and accurate, but highly invasive, aortic flow probe CO and LAP catheter measurements were simultaneously recorded during common hemodynamic interventions. Our results showed overall calibrated CO and absolute LAP root-mean-squared errors of 15.2% and 1.7 mmHg, respectively. For comparison, the root-mean-squared error of classic end-diastolic PAP estimates of LAP was 4.7 mmHg. On future successful human testing, the technique may potentially be employed for continuous hemodynamic monitoring in critically ill patients with pulmonary artery catheters. PMID:19057003

  10. Imminent Cardiac Risk Assessment via Optical Intravascular Biochemical Analysis

    SciTech Connect

    Wetzel, D.; Wetzel, L; Wetzel, M; Lodder, R

    2009-01-01

    Heart disease is by far the biggest killer in the United States, and type II diabetes, which affects 8% of the U.S. population, is on the rise. In many cases, the acute coronary syndrome and/or sudden cardiac death occurs without warning. Atherosclerosis has known behavioral, genetic and dietary risk factors. However, our laboratory studies with animal models and human post-mortem tissue using FT-IR microspectroscopy reveal the chemical microstructure within arteries and in the arterial walls themselves. These include spectra obtained from the aortas of ApoE-/- knockout mice on sucrose and normal diets showing lipid deposition in the former case. Also pre-aneurysm chemical images of knockout mouse aorta walls, and spectra of plaque excised from a living human patient are shown for comparison. In keeping with the theme of the SPEC 2008 conference Spectroscopic Diagnosis of Disease this paper describes the background and potential value of a new catheter-based system to provide in vivo biochemical analysis of plaque in human coronary arteries. We report the following: (1) results of FT-IR microspectroscopy on animal models of vascular disease to illustrate the localized chemical distinctions between pathological and normal tissue, (2) current diagnostic techniques used for risk assessment of patients with potential unstable coronary syndromes, and (3) the advantages and limitations of each of these techniques illustrated with patent care histories, related in the first person, by the physician coauthors. Note that the physician comments clarify the contribution of each diagnostic technique to imminent cardiac risk assessment in a clinical setting, leading to the appreciation of what localized intravascular chemical analysis can contribute as an add-on diagnostic tool. The quality of medical imaging has improved dramatically since the turn of the century. Among clinical non-invasive diagnostic tools, laboratory tests of body fluids, EKG, and physical examination are still the first line of defense. However, with the fidelity of 64-slice CT imaging, this technique has recently become an option when the patient presents with symptoms of reduced arterial flow. Single photon emission computerized tomography (SPECT) treadmill exercise testing is a standard non-invasive test for decreased perfusion of heart muscle, but is time consuming and not suited for emergent evaluation. Once the invasive clinical option of catherization is chosen, this provides the opportunity for intravascular ultrasound (IVUS) imaging. As the probe is pulled through the artery, the diameter at different parts is measurable, and monochrome contrast in the constricted area reveals the presence of tissue with a different ultrasonic response. Also, via an optical catheter with a fiber-optic conductor, the possibly of spectroscopic analysis of arterial walls is now a reality. In this case, the optical transducer is coupled to a near-infrared spectrometer. Revealing the arterial chemical health means that plaque vulnerability and imminent risk could be assessed by the physician. The classical emergency use of catherization involves a contrast agent and dynamic X-ray imaging to locate the constriction, determine its severity, and possibly perform angioplasty, and stent placement.

  11. The ability of stroke volume variation measured by a noninvasive cardiac output monitor to predict fluid responsiveness in mechanically ventilated children.

    PubMed

    Lee, Ji Yeon; Kim, Ji Young; Choi, Chang Hyu; Kim, Hong Soon; Lee, Kyung Cheon; Kwak, Hyun Jeong

    2014-02-01

    Continuous noninvasive cardiac output monitoring (NICOM) is a clinically useful tool in the pediatric setting. This study compared the ability of stroke volume variation (SVV) measured by NICOM with that of respiratory variations in the velocity of aortic blood flow (△Vpeak) and central venous pressure (CVP) to predict of fluid responsiveness in mechanically ventilated children after ventricular septal defect repair. The study investigated 26 mechanically ventilated children after the completion of surgery. At 30 min after their arrival in an intensive care unit, a colloid solution of 10 ml/kg was administrated for volume expansion. Hemodynamic variables, including CVP, stroke volume, and △Vpeak in addition to cardiac output and SVV in NICOM were measured before and 10 min after volume expansion. The patients with a stroke volume increase of more than 15 % after volume expansion were defined as responders. The 26 patients in the study consisted of 13 responders and 13 nonresponders. Before volume expansion, △Vpeak and SVV were higher in the responders (both p values <0.001). The areas under the receiver operating characteristic curves of △Vpeak, SVV, and CVP were respectively 0.956 (95 % CI 0.885-1.00), 0.888 (95 % CI 0.764-1.00), and 0.331 (95 % CI 0.123-0.540). This study showed that SVV by NICOM and △Vpeak by echocardiography, but not CVP, reliably predicted fluid responsiveness during mechanical ventilation after ventricular septal defect repair in children. PMID:23963186

  12. Pulse transit time measured by photoplethysmography improves the accuracy of heart rate as a surrogate measure of cardiac output, stroke volume and oxygen uptake in response to graded exercise.

    PubMed

    Pollonini, L; Padhye, N S; Re, R; Torricelli, A; Simpson, R J; Dacso, C C

    2015-05-01

    Heart rate (HR) is a valuable and widespread measure for physical training programs, although its description of conditioning is limited to the cardiac response to exercise. More comprehensive measures of exercise adaptation include cardiac output (Q̇), stroke volume (SV) and oxygen uptake (V̇O2), but these physiological parameters can be measured only with cumbersome equipment installed in clinical settings. In this work, we explore the ability of pulse transit time (PTT) to represent a valuable pairing with HR for indirectly estimating Q̇, SV and V̇O2 non-invasively. PTT was measured as the time interval between the peak of the electrocardiographic (ECG) R-wave and the onset of the photoplethysmography (PPG) waveform at the periphery (i.e. fingertip) with a portable sensor. Fifteen healthy young subjects underwent a graded incremental cycling protocol after which HR and PTT were correlated with Q̇, SV and V̇O2 using linear mixed models. The addition of PTT significantly improved the modeling of Q̇, SV and V̇O2 at the individual level ([Formula: see text] for SV, 0.548 for Q̇, and 0.771 for V̇O2) compared to predictive models based solely on HR ([Formula: see text] for SV, 0.503 for Q̇, and 0.745 for V̇O2). While challenges in sensitivity and artifact rejection exist, combining PTT with HR holds potential for development of novel wearable sensors that provide exercise assessment largely superior to HR monitors. PMID:25856085

  13. Using climate model output to assess the impacts of climate change on water resources

    SciTech Connect

    Cushman, R.M.

    1990-01-01

    The use of general circulation models (GCMs) to provide climate data for regional assessments of the impacts of changing climate on water resources stretches the limits of what the models were designed for. Problems that must be addressed include disagreement on a regional scale among GCMs and between the modeled and observed climate; coarse spatial resolution of the models; and simplistic representation of surface hydrology. It is important that continued progress be made in developing the methodology for using GCM output in climate-impact assessments. 18 refs.

  14. Phosphodiesterase inhibitor KMUP-3 displays cardioprotection via protein kinase G and increases cardiac output via G-protein-coupled receptor agonist activity and Ca(2+) sensitization.

    PubMed

    Liu, Chung-Pin; Yeh, Jwu-Lai; Liou, Shu-Fen; Wu, Bin-Nan; Chen, Ing-Jun

    2016-02-01

    KMUP-3 (7-{2-[4-(4-nitrobenzene) piperazinyl]ethyl}-1, 3-dimethylxanthine) displays cardioprotection and increases cardiac output, and is suggested to increase cardiac performance and improve myocardial infarction. To determine whether KMUP-3 improves outcomes in hypoperfused myocardium by inducing Ca(2+) sensitization to oppose protein kinase (PK)G-mediated Ca(2+) blockade, we measured left ventricular systolic blood pressure, maximal rates of pressure development, mean arterial pressure and heart rate in rats, and measured contractility and expression of PKs/RhoA/Rho kinase (ROCK)II in beating guinea pig left atria. Hemodynamic changes induced by KMUP-3 (0.5-3.0 mg/kg, intravenously) were inhibited by Y27632 [(R)-(+)-trans-4-1-aminoethyl)-N-(4-Pyridyl) cyclohexane carboxamide] and ketanserin (1 mg/kg, intravenously). In electrically stimulated left guinea pig atria, positive inotropy induced by KMUP-3 (0.1-100μM) was inhibited by the endothelial NO synthase (eNOS) inhibitors N-nitro-l-arginine methyl ester (L-NAME) and 7-nitroindazole, cyclic AMP antagonist SQ22536 [9-(terahydro-2-furanyl)-9H-purin-6-amine], soluble guanylyl cyclase (sGC) antagonist ODQ (1H-[1,2,4] oxadiazolo[4,3-a] quinoxalin-1-one), RhoA inhibitor C3 exoenzyme, β-blocker propranolol, 5-hydroxytryptamine 2A antagonist ketanserin, ROCK inhibitor Y27632 and KMUP-1 (7-{2-[4-(2-chlorobenzene) piperazinyl]ethyl}-1, 3-dimethylxanthine) at 10μM. Western blotting assays indicated that KMUP-3 (0.1-10μM) increased PKA, RhoA/ROCKII, and PKC translocation and CIP-17 (an endogenous 17-kDa inhibitory protein) activation. In spontaneous right atria, KMUP-3 induced negative chronotropy that was blunted by 7-nitroindazole and atropine. In neonatal myocytes, L-NAME inhibited KMUP-3-induced eNOS phosphorylation and RhoA/ROCK activation. In H9c2 cells, Y-27632 (50μM) and PKG antagonist KT5823 [2,3,9,10,11,12-hexahydro-10R- methoxy-2,9-dimethyl-1-oxo-9S,12R-epoxy-1H-diindolo(1,2,3-fg:3',2',1'-kl) pyrrolo(3,4-i)(1,6)benzodiazocine-10-carboxylic acid, methyl ester] (3μM) reversed KMUP-3 (1-100μM)-induced Ca(2+)-entry blockade. GPCR agonist activity of KMUP-3 appeared opposed to KMUP-1, and increased cardiac output via Ca(2+) sensitization, and displayed cardioprotection via cyclic GMP/PKG-mediated myocardial preconditioning in animal studies. PMID:26944323

  15. A model-free method for mass spectrometer response correction. [for oxygen consumption and cardiac output calculation

    NASA Technical Reports Server (NTRS)

    Shykoff, Barbara E.; Swanson, Harvey T.

    1987-01-01

    A new method for correction of mass spectrometer output signals is described. Response-time distortion is reduced independently of any model of mass spectrometer behavior. The delay of the system is found first from the cross-correlation function of a step change and its response. A two-sided time-domain digital correction filter (deconvolution filter) is generated next from the same step response data using a regression procedure. Other data are corrected using the filter and delay. The mean squared error between a step response and a step is reduced considerably more after the use of a deconvolution filter than after the application of a second-order model correction. O2 consumption and CO2 production values calculated from data corrupted by a simulated dynamic process return to near the uncorrupted values after correction. Although a clean step response or the ensemble average of several responses contaminated with noise is needed for the generation of the filter, random noise of magnitude not above 0.5 percent added to the response to be corrected does not impair the correction severely.

  16. Role Of Cardiac Mri In The Assessment Of Nonischemic Cardiomyopathies

    PubMed Central

    Nabi, Faisal

    2013-01-01

    In this review, we will highlight the role of late gadolinium enhancement, along with other strengths available by cardiac MRI, in determining the underlying etiology of various nonischemic cardiomyopathies. Furthermore, we will also emphasize how late gadolinium enhancement may serve as a novel risk stratification tool to further impact patient care. PMID:24066198

  17. The electrocardiogram in the assessment of the effect of drugs on cardiac arrhythmias.

    PubMed Central

    Reid, D S

    1978-01-01

    The search for the ideal antiarrhythmic drug continues since none of the available agents offers optimum antiarrhythmic therapy. The continuing search coupled with the interest in the mechanisms of cardiac arrhythmias has led to the development of new techniques for the study of arrhythmias and antiarrhythmic drugs. In this article it is proposed to discuss the electrocardiographic methods used in the assessment of antiarrhythmic drugs. Firstly, to discuss the electrocardiogram in the assessment of the clinical electrophysiological properties of a drug and secondly, the electrocardiogram in the assessment of the value of the drug in the management of cardiac arrhythmias in man. PMID:365208

  18. Assessment of pain during rest and during activities in the postoperative period of cardiac surgery

    PubMed Central

    de Mello, Larissa Coelho; Rosatti, Silvio Fernando Castro; Hortense, Priscilla

    2014-01-01

    Objective to assess the intensity and site of pain after Cardiac Surgery through sternotomy during rest and while performing five activities. Method descriptive study with a prospective cohort design. A total of 48 individuals participated in the study. A Multidimensional Scale for Pain Assessment was used. Results postoperative pain from cardiac surgery was moderate during rest and decreased over time. Pain was also moderate during activities performed on the 1st and 2nd postoperative days and decreased from the 3rd postoperative day, with the exception of coughing, which diminished only on the 6th postoperative day. Coughing, turning over, deep breathing and rest are presented in decreased order of intensity. The region of the sternum was the most frequently reported site of pain. Conclusion the assessment of pain in the individuals who underwent cardiac surgery during rest and during activities is extremely important to adapt management and avoid postoperative complications and delayed surgical recovery. PMID:24553714

  19. The new criterion for cardiac resynchronization therapy treatment assessed by two channels impedance cardiography

    NASA Astrophysics Data System (ADS)

    Peczalski, K.; Palko, T.; Wojciechowski, D.; Dunajski, Z.; Kowalewski, M.

    2013-04-01

    The cardiac resynchronization therapy is an effective treatment for systolic failure patients. Independent electrical stimulation of left and right ventricle corrects mechanical ventricular dyssynchrony. About 30-40% treated patients do not respond to therapy. In order to improve clinical outcome authors propose the two channels impedance cardiography for assessment of ventricular dyssynchrony. The proposed method is intended for validation of patients diagnosis and optimization of pacemaker settings for cardiac resynchronization therapy. The preliminary study has showed that bichannel impedance cardiography is a promising tool for assessment of ventricular dyssynchrony.

  20. Environmental impact assessment including indirect effects--a case study using input-output analysis

    SciTech Connect

    Lenzen, Manfred; Murray, Shauna A.; Korte, Britta; Dey, Christopher J

    2003-05-01

    Environmental impact assessment (EIA) is a process covered by several international standards, dictating that as many environmental aspects as possible should be identified in a project appraisal. While the ISO 14011 standard stipulates a broad-ranging study, off-site, indirect impacts are not specifically required for an Environmental Impact Statement (EIS). The reasons for this may relate to the perceived difficulty of measuring off-site impacts, or the assumption that these are a relatively insignificant component of the total impact. In this work, we describe a method that uses input-output analysis to calculate the indirect effects of a development proposal in terms of several indicator variables. The results of our case study of a Second Sydney Airport show that the total impacts are considerably higher than the on-site impacts for the indicators land disturbance, greenhouse gas emissions, water use, emissions of NO{sub x} and SO{sub 2}, and employment. We conclude that employing input-output analysis enhances conventional EIA, as it allows for national and international effects to be taken into account in the decision-making process.

  1. Short-Term Effects of Transjugular Intrahepatic Shunt on Cardiac Function Assessed by Cardiac MRI: Preliminary Results

    SciTech Connect

    Kovacs, A.; Schepke, M.; Heller, J.; Schild, H. H.; Flacke, S.

    2010-04-15

    The purpose of this study was to assess short-term effects of transjugular intrahepatic shunt (TIPS) on cardiac function with cardiac magnetic resonance imaging (MRI) in patients with liver cirrhosis. Eleven patients (six males and five females) with intractable esophageal varices or refractory ascites were imaged with MRI at 1.5 T prior to, within 24 h after, and 4-6 months after TIPS creation (n = 5). Invasive pressures were registered during TIPS creation. MRI consisted of a stack of contiguous slices as well as phase contrast images at all four valve planes and perpendicular to the portal vein. Imaging data were analyzed through time-volume curves and first derivatives. The portoatrial pressure gradient decreased from 19.8 {+-} 2.3 to 6.6 {+-} 2.3, accompanied by a nearly two fold increase in central pressures and pulmonary capillary wedge pressure immediately after TIPS creation. Left and right end diastolic volumes and stroke volumes increased by 11, 13, and 24%, respectively (p < 0.001), but dropped back to baseline at follow-up. End systolic volumes remained unchanged. E/A ratios remained within normal range. During follow-up the left ventricular mass was larger than baseline values in all patients, with an average increase of 7.9 g (p < 0.001). In conclusion, the increased volume load shunted to the heart after TIPS creation transiently exceeded the preload reserve of the right and left ventricle, leading to significantly increased pulmonary wedge pressures and persistent enlargement of the left and right atria. Normalization of cardiac dimensions was observed after months together with mild left ventricular hypertrophy.

  2. Assessing Cardiac Metabolism: A Scientific Statement From the American Heart Association.

    PubMed

    Taegtmeyer, Heinrich; Young, Martin E; Lopaschuk, Gary D; Abel, E Dale; Brunengraber, Henri; Darley-Usmar, Victor; Des Rosiers, Christine; Gerszten, Robert; Glatz, Jan F; Griffin, Julian L; Gropler, Robert J; Holzhuetter, Hermann-Georg; Kizer, Jorge R; Lewandowski, E Douglas; Malloy, Craig R; Neubauer, Stefan; Peterson, Linda R; Portman, Michael A; Recchia, Fabio A; Van Eyk, Jennifer E; Wang, Thomas J

    2016-05-13

    In a complex system of interrelated reactions, the heart converts chemical energy to mechanical energy. Energy transfer is achieved through coordinated activation of enzymes, ion channels, and contractile elements, as well as structural and membrane proteins. The heart's needs for energy are difficult to overestimate. At a time when the cardiovascular research community is discovering a plethora of new molecular methods to assess cardiac metabolism, the methods remain scattered in the literature. The present statement on "Assessing Cardiac Metabolism" seeks to provide a collective and curated resource on methods and models used to investigate established and emerging aspects of cardiac metabolism. Some of those methods are refinements of classic biochemical tools, whereas most others are recent additions from the powerful tools of molecular biology. The aim of this statement is to be useful to many and to do justice to a dynamic field of great complexity. PMID:27012580

  3. Assessment of Cardiac Motion Effects on the Fiber Architecture of the Human Heart In Vivo

    PubMed Central

    Viallon, Magalie; Delattre, Benedicte M. A.; Wang, Lihui; Pai, Vinay M.; Wen, Han; Xue, Hui; Guetter, Christoph; Croisille, Pierre; Zhu, Yuemin

    2015-01-01

    The use of diffusion tensor imaging (DTI) for studying the human heart in vivo is very challenging due to cardiac motion. This paper assesses the effects of cardiac motion on the human myocardial fiber architecture. To this end, a model for analyzing the effects of cardiac motion on signal intensity is presented. A Monte-Carlo simulation based on polarized light imaging data is then performed to calculate the diffusion signals obtained by the displacement of water molecules, which generate diffusion weighted (DW) images. Rician noise and in vivo motion data obtained from DENSE acquisition are added to the simulated cardiac DW images to produce motion-induced datasets. An algorithm based on principal components analysis filtering and temporal maximum intensity projection (PCATMIP) is used to compensate for motion-induced signal loss. Diffusion tensor parameters derived from motion-reduced DW images are compared to those derived from the original simulated DW images. Finally, to assess cardiac motion effects on in vivo fiber architecture, in vivo cardiac DTI data processed by PCATMIP are compared to those obtained from one trigger delay (TD) or one single phase acquisition. The results showed that cardiac motion produced overestimated fractional anisotropy and mean diffusivity as well as a narrower range of fiber angles. The combined use of shifted TD acquisitions and postprocessing based on image registration and PCATMIP effectively improved the quality of in vivo DW images and subsequently, the measurement accuracy of fiber architecture properties. This suggests new solutions to the problems associated with obtaining in vivo human myocardial fiber architecture properties in clinical conditions. PMID:23797241

  4. Assessment of cardiac motion effects on the fiber architecture of the human heart in vivo.

    PubMed

    Wei, Hongjiang; Viallon, Magalie; Delattre, Benedicte M A; Wang, Lihui; Pai, Vinay M; Wen, Han; Xue, Hui; Guetter, Christoph; Croisille, Pierre; Zhu, Yuemin

    2013-10-01

    The use of diffusion tensor imaging (DTI) for studying the human heart in vivo is very challenging due to cardiac motion. This paper assesses the effects of cardiac motion on the human myocardial fiber architecture. To this end, a model for analyzing the effects of cardiac motion on signal intensity is presented. A Monte-Carlo simulation based on polarized light imaging data is then performed to calculate the diffusion signals obtained by the displacement of water molecules, which generate diffusion weighted (DW) images. Rician noise and in vivo motion data obtained from DENSE acquisition are added to the simulated cardiac DW images to produce motion-induced datasets. An algorithm based on principal components analysis filtering and temporal maximum intensity projection (PCATMIP) is used to compensate for motion-induced signal loss. Diffusion tensor parameters derived from motion-reduced DW images are compared to those derived from the original simulated DW images. Finally, to assess cardiac motion effects on in vivo fiber architecture, in vivo cardiac DTI data processed by PCATMIP are compared to those obtained from one trigger delay (TD) or one single phase acquisition. The results showed that cardiac motion produced overestimated fractional anisotropy and mean diffusivity as well as a narrower range of fiber angles. The combined use of shifted TD acquisitions and postprocessing based on image registration and PCATMIP effectively improved the quality of in vivo DW images and subsequently, the measurement accuracy of fiber architecture properties. This suggests new solutions to the problems associated with obtaining in vivo human myocardial fiber architecture properties in clinical conditions. PMID:23797241

  5. Interruption of cardiac output does not affect short-term growth and metabolic rate in day 3 and 4 chick embryos.

    PubMed

    Burggren, W W; Warburton, S J; Slivkoff, M D

    2000-12-01

    The heart beat of vertebrate embryos has been assumed to begin when convective bulk transport by blood takes over from transport by simple diffusion. To test this hypothesis, we measured eye growth, cervical flexure and rates of oxygen consumption ( V(O2)) in day 3-4 chick embryos denied cardiac output by ligation of the outflow tract and compared them with those of embryos with an intact cardiovascular system. Eye diameter, used as the index for embryonic growth, increased at a rate of approximately 4.5-5 % h(-)(1) during the observation period. There was no significant difference (P>0.1) in the rate of increase in eye diameter between control (egg opened), sham-ligated (ligature present but not tied) and ligated embryos. Similarly, the normal progression of cervical flexure was not significantly altered by ligation (P>0.1). V(O2) (ml O(2 )g(-)(1 )h(-)(1)) at 38 degrees C, measured by closed respirometry, was not significantly different (P>0.1) on day 3 in sham-ligated (14.5+/-1.9 ml O(2 )g(-)(1 )h(-)(1)) and ligated 17.6+/-1.8 ml O(2 )g(-)(1 )h(-)(1)) embryos. Similarly, on day 4, V(O2) in sham-ligated and ligated embryos was statistically the same (sham-ligated 10. 5+/-2.9 ml O(2 )g(-)(1 )h(-)(1); ligated 9.7+/-2.9 ml O(2 )g(-)(1 )h(-)(1)). Expressed as a linear function of body mass (M), V(O2) in sham-ligated embryos was described by the equation V(O2)=-0.48M+24.06 (r(2)=0.36, N=18, P<0.01), while V(O2) in ligated embryos was described by the equation V(O2)=-0.53M+23.32 (r(2)=0.38, N=16, P<0.01). The regression line describing the relationship between body mass and V(O2) for pooled sham-ligated and ligated embryos (the two populations being statistically identical) was V(O2)=-0.47M+23.24. The slope of this regression line, which was significantly different from zero (r(2)=0.30, N=34, P<0.01), was similar to slopes calculated from previous studies over the same range of body mass.Collectively, these data indicate that growth and V(O2) are not dependent upon cardiac output and the convective blood flow it generates. Thus, early chick embryos join those of the zebrafish, clawed frog and axolotl in developing a heart beat and blood flow hours or days before required for convective oxygen and nutrient transport. We speculate that angiogenesis is the most likely role for the early development of a heart beat in vertebrate embryos. PMID:11076745

  6. Increased cardiac output, not pulmonary artery systolic pressure, increases intrapulmonary shunt in healthy humans breathing room air and 40% O2

    PubMed Central

    Elliott, Jonathan E; Duke, Joseph W; Hawn, Jerold A; Halliwill, John R; Lovering, Andrew T

    2014-01-01

    Blood flow through intrapulmonary arteriovenous anastomoses (IPAVAs) has been demonstrated to increase in healthy humans during a variety of conditions; however, whether or not this blood flow represents a source of venous admixture (/) that impairs pulmonary gas exchange efficiency (i.e. increases the alveolar-to-arterial difference (A–aDO2)) remains controversial and unknown. We hypothesized that blood flow through IPAVAs does provide a source of /. To test this, blood flow through IPAVAs was increased in healthy humans at rest breathing room air and 40% O2: (1) during intravenous adrenaline (epinephrine) infusion at 320 ng kg−1 min−1 (320 ADR), and (2) with vagal blockade (2 mg atropine), before and during intravenous adrenaline infusion at 80 ng kg−1 min−1 (ATR + 80 ADR). When breathing room air the A–aDO2 increased by 6 ± 2 mmHg during 320 ADR and by 5 ± 2 mmHg during ATR + 80 ADR, and the change in calculated / was +2% in both conditions. When breathing 40% O2, which minimizes contributions from diffusion limitation and alveolar ventilation-to-perfusion inequality, the A–aDO2 increased by 12 ± 7 mmHg during 320 ADR, and by 9 ± 6 mmHg during ATR + 80 ADR, and the change in calculated / was +2% in both conditions. During 320 ADR cardiac output () and pulmonary artery systolic pressure (PASP) were significantly increased; however, during ATR + 80 ADR only was significantly increased, yet blood flow through IPAVAs as detected with saline contrast echocardiography was not different between conditions. Accordingly, we suggest that blood flow through IPAVAs provides a source of intrapulmonary shunt, and is mediated primarily by increases in rather than PASP. PMID:25085889

  7. Jason-1: Main Outputs of The Assessment Phase and Preliminary Verification Results

    NASA Astrophysics Data System (ADS)

    Perbos, J.; Vincent, P.; Desai, S.; Menard, Y.; Fu, L. L.; Haines, B.; Parisot, F.; Escudier, P.; Kunstmann, G.

    On December 7, 2001, Jason-1 was successfully launched by a Boeing Delta 2 rocket from the Vandenberg site, CA. This satellite will maintain the high accuracy altime- ter service provided since 1992 by TOPEX/POSEIDON (T/P), ensuring the continu- ity in observing and monitoring the Ocean Dynamics (intra-seasonal to inter-annual changes, mean sea level, tides...). Despite four times less mass and power, the Jason-1 system has been designed to basically have the same performances as T/P, measuring sea surface topography at a centimetric level. This new CNES/NASA mission, also provides near real-time data for sea state and ocean forecast. The first 2 months of the Jason mission are dedicated to the assessment of the overall system. The goal is to check that all the elements of the onboard and ground systems are within the specifications : It concerns the satellite, the payload and the overall control and mission ground segment. After completion of the "Assessment phase" on mid-February 2002, Jason-1 entered a 6 month duration "Verification phase". Deriva- tion of the performances and error budget of the system and products is the major goal of this phase. In addition, various validation activities conducted by the Science and Project Teams of the mission will have started: global statistical analysis, in-situ and regional calibration and validation experiments, multi-satellite comparisons. of course, special care will be paid to T/P and Jason cross-calibration as the two satel- lites follow each other only 1 minute apart. Few weeks after the end of the assessment phase and the start of the verification phase, the main outputs demonstrating that the overall Jason-1 system is assessed will be presented. Preliminary validation results will also be displayed in this conference.

  8. Life Cycle Assessment of Mixed Municipal Solid Waste: Multi-input versus multi-output perspective.

    PubMed

    Fiorentino, G; Ripa, M; Protano, G; Hornsby, C; Ulgiati, S

    2015-12-01

    This paper analyses four strategies for managing the Mixed Municipal Solid Waste (MMSW) in terms of their environmental impacts and potential advantages by means of Life Cycle Assessment (LCA) methodology. To this aim, both a multi-input and a multi-output approach are applied to evaluate the effect of these perspectives on selected impact categories. The analyzed management options include direct landfilling with energy recovery (S-1), Mechanical-Biological Treatment (MBT) followed by Waste-to-Energy (WtE) conversion (S-2), a combination of an innovative MBT/MARSS (Material Advanced Recovery Sustainable Systems) process and landfill disposal (S-3), and finally a combination of the MBT/MARSS process with WtE conversion (S-4). The MARSS technology, developed within an European LIFE PLUS framework and currently implemented at pilot plant scale, is an innovative MBT plant having the main goal to yield a Renewable Refined Biomass Fuel (RRBF) to be used for combined heat and power production (CHP) under the regulations enforced for biomass-based plants instead of Waste-to-Energy systems, for increased environmental performance. The four scenarios are characterized by different resource investment for plant and infrastructure construction and different quantities of matter, heat and electricity recovery and recycling. Results, calculated per unit mass of waste treated and per unit exergy delivered, under both multi-input and multi-output LCA perspectives, point out improved performance for scenarios characterized by increased matter and energy recovery. Although none of the investigated scenarios is capable to provide the best performance in all the analyzed impact categories, the scenario S-4 shows the best LCA results in the human toxicity and freshwater eutrophication categories, i.e. the ones with highest impacts in all waste management processes. PMID:26257056

  9. [Remote monitoring of implantable cardiac devices: health technology assessment ].

    PubMed

    Ricci, Renato Pietro; Locati, Emanuela Teresa; Campana, Andrea; Cavallaro, Ciro; Giammaria, Massimo; Landolina, Maurizio; Marzegalli, Maurizio; Melissano, Donato

    2015-05-01

    Clinical follow-up of patients with cardiac implantable electronic devices is challenging because of the increasing technical complexity of devices and clinical complexity of patients. Remote monitoring (RM) offers the opportunity to optimize clinic workflow and to improve device monitoring and patient management by reducing in-hospital visits, physician and nurse time required for patient follow-up, and hospital and social costs. Continuous RM may lead to early detection of device malfunctions and clinical events, such as arrhythmias and heart failure. Early reaction may improve patient outcome. RM is easy to use and patients show a high level of acceptance and satisfaction. Implementing RM in daily practice may require changes in clinical workflow. Primary nursing-based models have demonstrated the best results. In spite of a favorable cost-benefit ratio, RM reimbursement still represents an issue in several European countries, including Italy, which limits widespread RM utilization. The fee-for-service payment approach, the global budget for device patient follow-up and/or integrated care packages for heart failure management represent the keys to introduce reimbursement and to improve patient care, while reducing healthcare costs. PMID:25994466

  10. Heart rate complexity: A novel approach to assessing cardiac stress reactivity.

    PubMed

    Brindle, Ryan C; Ginty, Annie T; Phillips, Anna C; Fisher, James P; McIntyre, David; Carroll, Douglas

    2016-04-01

    Correlation dimension (D2), a measure of heart rate (HR) complexity, has been shown to decrease in response to acute mental stress and relate to adverse cardiovascular health. However, the relationship between stress-induced changes in D2 and HR has yet to be established. The present studies aimed to assess this relationship systematically while controlling for changes in respiration and autonomic activity. In Study 1 (N = 25) D2 decreased during stress and predicted HR reactivity even after adjusting for changes in respiration rate, and cardiac vagal tone. This result was replicated in Study 2 (N = 162) and extended by including a measure of cardiac sympathetic activity; correlation dimension remained an independent predictor of HR reactivity in a hierarchical linear model containing measures of cardiac parasympathetic and sympathetic activity and their interaction. These results suggest that correlation dimension may provide additional information regarding cardiac stress reactivity above that provided by traditional measures of cardiac autonomic function. PMID:26585809

  11. Integrating input output analysis with risk assessment to evaluate the population risk of arsenic.

    PubMed

    Ma, Hwong-Wen; Shih, Hsiu-Ching; Hung, Ming-Lung; Chao, Chia-Wei; Li, Pei-Chiun

    2012-01-17

    Multimedia and site-specific risk assessments (RA) of major sources releasing arsenic (As) were converted into sector-based risk coefficients, which were integrated with the Input Output Table (IO) to analyze the association between sector activities and health risks. The developed IO-RA framework is a valuable tool for unfolding the risk chain linking the receptors, exposure pathways, emission sources, and production and consumption activities associated with various industrial sectors. The enlarged decision space along the chain can then be considered in planning risk management strategies. This case study estimates that air emissions of As result in 1.54 carcinogenic cases. Export is the primary driving force and accounts for approximately 48% of the final demand that leads to population risks of As. The ranking of the contribution of the five sectors in terms of total population risks is as follows: electricity supply (1.06E+00), steelmaking (2.2 × 10(-1)), cement kilns (1.50 × 10(-1)), semiconductor manufacturing (6.34 × 10(-2)) and incinerators (4.31 × 10(-2)). The electricity supply, steelmaking industry, and cement kilns are the major sectors, not only because their emissions directly cause risk but also because they have a stronger influence on the risk generated by other sectors. PMID:22192073

  12. Assessing and Improving Land Surface Model Outputs Over Africa Using GRACE, Field, and Remote Sensing Data

    NASA Astrophysics Data System (ADS)

    Ahmed, Mohamed; Sultan, Mohamed; Yan, Eugene; Wahr, John

    2016-02-01

    The Gravity Recovery and Climate Experiment (GRACE), along with other relevant field and remote sensing datasets, was used to assess the performance of two land surface models (LSMs: CLM4.5-SP and GLDAS-Noah) over the African continent and improve the outputs of the CLM4.5-SP model. Spatial and temporal analysis of monthly (January 2003-December 2010) Terrestrial Water Storage (TWS) estimates extracted from GRACE (TWSGRACE), CLM4.5-SP (TWSCLM4.5), and GLDAS-Noah (TWSGLDAS) indicates the following: (1) compared to GRACE, LSMs overestimate TWS in winter months and underestimate them in summer months; (2) the amplitude of annual cycle (AAC) of TWSGRACE is higher than that of TWSLSM (AAC: TWSGRACE > TWSGLDAS > TWSCLM4.5); (3) higher, and statistically significant correlations were observed between TWSGRACE and TWSGLDAS compared to those between TWSGRACE and TWSCLM4.5; (4) differences in forcing precipitation and temperature datasets for GLDAS-Noah and CLM4.5-SP models are unlikely to be the main cause for the observed discrepancies between TWSGRACE and TWSLSM; and (5) the CLM4.5-SP model overestimates evapotranspiration (ET) values in summer months and underestimates them in winter months compared to ET estimates extracted from field-based (FLUXNET-MTE) and satellite-based (MOD16 and GLEAM) ET measurements. A first-order correction was developed and applied to correct the CLM4.5-derived ET, soil moisture, groundwater, and TWS. The corrections improved the correspondence (i.e., higher correlation and comparable AAC) between TWSCLM4.5 and TWSGRACE over various climatic settings. Our findings suggest that similar straightforward correction approaches could potentially be developed and used to assess and improve the performance of a wide range of LSMs.

  13. Assessing and Improving Land Surface Model Outputs Over Africa Using GRACE, Field, and Remote Sensing Data

    NASA Astrophysics Data System (ADS)

    Ahmed, Mohamed; Sultan, Mohamed; Yan, Eugene; Wahr, John

    2016-05-01

    The Gravity Recovery and Climate Experiment (GRACE), along with other relevant field and remote sensing datasets, was used to assess the performance of two land surface models (LSMs: CLM4.5-SP and GLDAS-Noah) over the African continent and improve the outputs of the CLM4.5-SP model. Spatial and temporal analysis of monthly (January 2003-December 2010) Terrestrial Water Storage (TWS) estimates extracted from GRACE (TWSGRACE), CLM4.5-SP (TWSCLM4.5), and GLDAS-Noah (TWSGLDAS) indicates the following: (1) compared to GRACE, LSMs overestimate TWS in winter months and underestimate them in summer months; (2) the amplitude of annual cycle (AAC) of TWSGRACE is higher than that of TWSLSM (AAC: TWSGRACE > TWSGLDAS > TWSCLM4.5); (3) higher, and statistically significant correlations were observed between TWSGRACE and TWSGLDAS compared to those between TWSGRACE and TWSCLM4.5; (4) differences in forcing precipitation and temperature datasets for GLDAS-Noah and CLM4.5-SP models are unlikely to be the main cause for the observed discrepancies between TWSGRACE and TWSLSM; and (5) the CLM4.5-SP model overestimates evapotranspiration (ET) values in summer months and underestimates them in winter months compared to ET estimates extracted from field-based (FLUXNET-MTE) and satellite-based (MOD16 and GLEAM) ET measurements. A first-order correction was developed and applied to correct the CLM4.5-derived ET, soil moisture, groundwater, and TWS. The corrections improved the correspondence (i.e., higher correlation and comparable AAC) between TWSCLM4.5 and TWSGRACE over various climatic settings. Our findings suggest that similar straightforward correction approaches could potentially be developed and used to assess and improve the performance of a wide range of LSMs.

  14. Enhanced DEA model with undesirable output and interval data for rice growing farmers performance assessment

    NASA Astrophysics Data System (ADS)

    Khan, Sahubar Ali Mohd. Nadhar; Ramli, Razamin; Baten, M. D. Azizul

    2015-12-01

    Agricultural production process typically produces two types of outputs which are economic desirable as well as environmentally undesirable outputs (such as greenhouse gas emission, nitrate leaching, effects to human and organisms and water pollution). In efficiency analysis, this undesirable outputs cannot be ignored and need to be included in order to obtain the actual estimation of firms efficiency. Additionally, climatic factors as well as data uncertainty can significantly affect the efficiency analysis. There are a number of approaches that has been proposed in DEA literature to account for undesirable outputs. Many researchers has pointed that directional distance function (DDF) approach is the best as it allows for simultaneous increase in desirable outputs and reduction of undesirable outputs. Additionally, it has been found that interval data approach is the most suitable to account for data uncertainty as it is much simpler to model and need less information regarding its distribution and membership function. In this paper, an enhanced DEA model based on DDF approach that considers undesirable outputs as well as climatic factors and interval data is proposed. This model will be used to determine the efficiency of rice farmers who produces undesirable outputs and operates under uncertainty. It is hoped that the proposed model will provide a better estimate of rice farmers' efficiency.

  15. Productivity in Academia: An Assessment of Causal Linkages between Output and Outcome Indicators

    ERIC Educational Resources Information Center

    Wamala, Robert; Ssembatya, Vincent A.

    2015-01-01

    Purpose: The purpose of this paper is to investigate causal linkages between output and outcome indicators of productivity in academia. Design/methodology/approach: The duration of teaching service and the number of graduate students supervised to completion were adopted as output indicators of productivity. Equivalent outcome indicators were the…

  16. Assessing satellite AOD based and WRF/CMAQ output PM2.5 estimators

    NASA Astrophysics Data System (ADS)

    Cordero, Lina; Wu, Yonghua; Gross, Barry M.; Moshary, Fred

    2013-05-01

    Fine particulate matter measurements (PM2.5) are essential for air quality monitoring and related public health; however, the shortage of reliable measurmennts constrains researchers to use other means for obtaining reliable estimates over large scales. In particular, model forecasters and satellite community use their respective products to develop ground particulate matter estimations but few experiments have explored how the remote sensing approaches compare to the high resolution models. . In this paper we focus on studying the performance of the Moderate Resolution Imaging Spectroradiometer (MODIS) and the Geostationary Operational Environmental Satellites (GOES) regression based estimates in comparison to more direct bias corrected outputs from the Community Multiscale Air Quality (CMAQ) model, We use a two-year dataset (2005-2006) and apply urban, season and hour filters to illustrate the agreement between estimated and in-situ measured fine particulate matter from the New York State Department of Environmental Conservation (NYSDEC). We first begin by analyzing the correspondence between ground aerosol optical depth (AOD) measurements from an AERONET (AErosol RObotic NETwork) Cimel sun/sky radiometer with both satellite and model products in one urban location; we show that satellite readings perform better than model outputs, especially during the summer (RMODIS>=0.65, RCMAQ>=0.37). This is a clear symptom of the difficulty in the models to properly model realistic optical properties. We then turn to a direct assessment of PM2.5 presenting individual comparisons between ground PM2.5 measurements with satellite/model predictions and demonstrate the higher accuracy from model estimations (RurbanMODIS >= 0.74, RurbanCMAQ >= 0.77; Rnon-urbanMODIS >= 0.48, Rnon-urbanCMAQ >= 0.78). In general, we find that the bias corrected CMAQ estimates are superior to satellite based estimators except at very high resolution. Finally, we show that when using both model and satellite approximations as separate estimators merged optimally, our product (PM2.5 average) becomes closer to real measurements with improved correlations (RAVE ~ 0.86) in urban areas during the summer.

  17. Effects of active chronic cocaine use on cardiac sympathetic neuronal function assessed by carbon-11-hydroxyephedrine

    SciTech Connect

    Melon, P.G.; Boyd, C.J.; McVey, S. |

    1997-03-01

    Cardiac toxicity of cocaine has been linked to its inhibitory effect on norepinephrine reuptake by sympathetic nerve terminals of the heart. Carbon-11-hydroxyephedrine is a positron-emitting tracer that has been validated as a highly specific marker for norepinephrine transporter activity of the sympathetic nerve terminals and thus makes possible in vivo assessment of the effect of cocaine on norepinephrine reuptake and storage in the cardiac sympathetic nerve terminals. The aim of the study was to use the catecholamine analog {sup 11}C-hydroxyephedrine with PET to determine whether active chronic use of cocaine in women modifies the function of sympathetic nerve terminals of the heart. Six normal female volunteers and nine female active chronic cocaine users were studied. Cardiac regional {sup 11}C-hydroxyephedrine uptake and blood flow, as assessed with {sup 13}N-ammonia, were determined using semi-quantitative polar map analysis of myocardial tracer distribution. Carbon-11-hydroxyephedrine cardiac retention was quantified using dynamic data acquisition and kinetic analysis of blood and tissue activity. 27 refs., 4 figs., 3 tabs.

  18. Noninvasive Assessment of Tissue Heating During Cardiac Radiofrequency Ablation Using MRI Thermography

    PubMed Central

    Kolandaivelu, Aravindan; Zviman, Menekhem M.; Castro, Valeria; Lardo, Albert C.; Berger, Ronald D.; Halperin, Henry R.

    2010-01-01

    Background Failure to achieve properly localized, permanent tissue destruction is a common cause of arrhythmia recurrence after cardiac ablation. Current methods of assessing lesion size and location during cardiac radiofrequency ablation are unreliable or not suited for repeated assessment during the procedure. MRI thermography could be used to delineate permanent ablation lesions because tissue heating above 50°C is the cause of permanent tissue destruction during radiofrequency ablation. However, image artifacts caused by cardiac motion, the ablation electrode, and radiofrequency ablation currently pose a challenge to MRI thermography in the heart. In the current study, we sought to demonstrate the feasibility of MRI thermography during cardiac ablation. Methods and Results An MRI-compatible electrophysiology catheter and filtered radiofrequency ablation system was used to perform ablation in the left ventricle of 6 mongrel dogs in a 1.5-T MRI system. Fast gradient-echo imaging was performed before and during radiofrequency ablation, and thermography images were derived from the preheating and postheating images. Lesion extent by thermography was within 20% of the gross pathology lesion. Conclusions MR thermography appears to be a promising technique for monitoring lesion formation and may allow for more accurate placement and titration of ablation, possibly reducing arrhythmia recurrences. PMID:20657028

  19. The assessment of cardiac autonomic functions in adolescents with a family history of premature atherosclerosis

    PubMed Central

    Dursun, Huseyin; Kilicaslan, Baris; Aydin, Mehmet

    2014-01-01

    OBJECTIVES: Subclinical atherosclerosis has been recently detected in adolescents with a family history of premature atherosclerosis. However, no studies in the literature have assessed the cardiac autonomic functions of these adolescents. The aim of this study was to evaluate the cardiac autonomic functions of adolescents with a family history of premature atherosclerosis compared with those of age- and gender-matched adolescents without a family history of atherosclerosis. METHOD: We evaluated the cardiac autonomic functions of 36 adolescents with a family history of premature atherosclerosis (Group 1) and compared them with those of 31 age- and gender-matched adolescents whose parents did not have premature atherosclerosis (Group 2). Twenty-four-hour time domain (standard deviation of all normal sinus RR intervals [SDNN], standard deviation of the mean of normal RR intervals in each 5-minute segment [SDANN], root-mean-square differences in successive RR intervals) and frequency domain (very low frequency, low frequency, high frequency, low frequency/high frequency) parameters of heart rate variability were used for the evaluation of cardiac autonomic functions. RESULTS: There were no differences in the time and frequency domain parameters of heart rate variability between the two groups. Heart rate was negatively correlated with SDNN (r = -0.278, p = 0.035), while age was significantly correlated with root-mean-square differences in successive RR intervals, high frequency, low frequency and low frequency/high frequency (r = -0.264, -0.370, 0.265 and 0.374, respectively; p<0.05 for all). CONCLUSION: We found that the cardiac autonomic functions of adolescents with a family history of premature atherosclerosis were not different compared with those of adolescents without a positive family history of premature atherosclerosis. It appears that subclinical atherosclerosis does not reach a critical value such that it can alter cardiac autonomic functions in adolescence. PMID:25627994

  20. Renal Doppler and Novel Biomarkers to Assess Acute Kidney Injury in a Swine Model of Ventricular Fibrillation Cardiac Arrest

    PubMed Central

    Mei, Xue; Hang, Chen-Chen; Wang, Shuo; Li, Chun-Sheng; Yu, Ze-Xing

    2015-01-01

    Background: Majority of the research on cardiac arrest (CA) have focused on post-CA brain injury and myocardial dysfunction, the renal dysfunction and acute kidney injury (AKI) in other critical illnesses after CA have not been well described. This study was designed to assess AKI with renal Doppler and novel AKI biomarkers in a swine model of ventricular fibrillation cardiac arrest (VFCA). Methods: Thirty healthy piglets were divided into VFCA group (n = 22) and Sham group (n = 8) in a blinded manner. Mean arterial pressure, heart rate, and cardiac output were recorded continuously. Cardiac arrest (CA) was induced by programmed electric stimulation in the VFCA group, and then cardiopulmonary resuscitation was performed. Twenty piglets returned of spontaneous circulation (ROSC) and received intensive care. Blood and urine samples were collected for AKI biomarkers testing, and Color Doppler flow imaging was performed at baseline, 6 h, 12 h, and 24 h, respectively after ROSC. At ROSC 24 h, the animals were sacrificed and a semi-quantitative evaluation of pathologic kidney injury was performed. Results: In the VFCA group, corrected resistive index (cRI) increased from 0.47 ± 0.03 to 0.64 ± 0.06, and pulsatility index (PI) decreased from 0.82 ± 0.03 to 0.68 ± 0.04 after ROSC. Cystatin C (CysC) in both serum and urine samples increased at ROSC 6 h, but neutrophil gelatinase-associated lipocalin (NGAL) in serum increased to 5.34 ± 1.68 ng/ml at ROSC 6 h, and then decreased to 3.16 ± 0.69 ng/ml at ROSC 24 h while CysC increasing constantly. According to the renal histopathology, 18 of 20 animals suffered from kidney injury. The grade of renal injury was highly correlated with RI, cRI, NGAL, and CysC. Linear regression equation was established: Grade of renal injury = 0.002 × serum CysC + 6.489 × PI + 4.544 × cRI – 8.358 (r2 = 0.698, F = 18.506, P < 0.001). Conclusions: AKI is common in post-CA syndrome. Renal Doppler and novel AKI biomarkers in serum and urine are of significant importance as early predictors of post-CA AKI. PMID:26608988

  1. Noninvasive Physiologic Assessment of Coronary Stenoses Using Cardiac CT

    PubMed Central

    Fan, Zhanming

    2015-01-01

    Coronary CT angiography (CCTA) has become an important noninvasive imaging modality in the diagnosis of coronary artery disease (CAD). CCTA enables accurate evaluation of coronary artery stenosis. However, CCTA provides limited information on the physiological significance of stenotic lesions. A noninvasive one-stop-shop diagnostic test that can provide both anatomical significance and functional significance of stenotic lesions would be beneficial in the diagnosis and management of CAD. Recently, with the introduction of novel techniques, such as myocardial CT perfusion, CT-derived fractional flow reserve (FFRCT), and transluminal attenuation gradient (TAG), CCTA has emerged as a noninvasive method for the assessment of both anatomy of coronary lesions and its physiological consequences during a single study. This review provides an overview of the current status of new CT techniques for the physiologic assessments of CAD. PMID:25685790

  2. Spatiotemporal Downscaling of Global Climate Model Output for Assessing Soil Erosion and Crop Production Under Climate Change.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Spatial and temporal mismatches between coarse resolution output of General Circulation Models (GCMs) and fine resolution data requirements of ecosystems models are the major obstacles for assessing the site-specific climatic impacts of climate change on natural resources and ecosystems. The object...

  3. Assessing the blalock-hanlon atrioseptectomy at cardiac catheterization.

    PubMed

    Clark, E B; Rosenquist, G C

    1977-01-01

    Blalock-Hanlon atrial septectomy (BH) is performed to increase systemic and pulmonary venous mixing at the atrial level. Failure of clinical improvement may be related to inadequate intraatrial communication. A simple catheterization technique employing a balloon catheter is used to assess the presence or absence of the limbus of the foramen ovale following BH, since persistence of the limbus of the fossa ovalis after BH is associated with significantly smaller percentage of communication (atrial communication area/total atrial area). PMID:603909

  4. Assessing Risks and Benefits of Invasive Cardiac Procedures in Patients with Advanced Multimorbidity.

    PubMed

    Orkaby, Ariela R; Forman, Daniel E

    2016-05-01

    Age-related cardiovascular disease in older adults is more likely to occur in combination with other age-related diseases, with mounting interactive complexity as multiple morbidities accumulate. Although invasive cardiac procedures are frequently recommended for cardiovascular disease, their value is less certain in the context of age-related intricacies of care. Tools for risk assessment before invasive procedures are insensitive to risks corresponding to the unique challenges of older adults. Recognizing multimorbidity and other age-related risks provides opportunities to intervene and moderate dangers. By refocusing risk assessment in terms of patient-centered goals, the fundamental utility of invasive cardiac procedures may be reconsidered and alternative therapies prioritized. PMID:27113152

  5. Evaluation of optical imaging and spectroscopy approaches for cardiac tissue depth assessment

    SciTech Connect

    Lin, B; Matthews, D; Chernomordik, V; Gandjbakhche, A; Lane, S; Demos, S G

    2008-02-13

    NIR light scattering from ex vivo porcine cardiac tissue was investigated to understand how imaging or point measurement approaches may assist development of methods for tissue depth assessment. Our results indicate an increase of average image intensity as thickness increases up to approximately 2 mm. In a dual fiber spectroscopy configuration, sensitivity up to approximately 3 mm with an increase to 6 mm when spectral ratio between selected wavelengths was obtained. Preliminary Monte Carlo results provided reasonable fit to the experimental data.

  6. Bleeding risk assessment using whole blood impedance aggregometry and rotational thromboelastometry in patients following cardiac surgery.

    PubMed

    Petricevic, Mate; Biocina, Bojan; Milicic, Davor; Konosic, Sanja; Svetina, Lucija; Leki?, Ante; Zdilar, Boris; Burcar, Ivan; Milosevic, Milan; Brahimaj, Rifat; Samardzic, Jure; Gasparovic, Hrvoje

    2013-11-01

    Excessive bleeding after cardiopulmonary bypass (CPB) is risk factor for adverse outcomes after elective cardiac surgery (ECS). Differentiating between patients who bleed due to surgical issues and those whose excessive chest tube output (CTO) is due to coagulopathy, remains challenging. Bedside suitable tests to identify hemostatic disturbances and predict excessive bleeding are desirable. The study sought to evaluate prediction of excessive bleeding after ECS using two bedside suitable devices for platelet function and viscoelastic blood clot properties assessment. We enrolled 148 patients (105 male and 43 female) undergoing ECS in a prospective observational study. Patients were characterized as bleeders if their 24 h CTO exceeded the 75th percentile of distribution. Multiple electrode aggregometry (MEA, with ASPI, ADP and the TRAP test) and rotational thromboelastometry (TEM, with ExTEM, HepTEM and FibTEM test), were performed at three time points: preoperatively (T1), during CPB (T2), and after protamine administration (T3). The primary endpoint was CTO and the secondary endpoint was administration of blood products, 30-day and 1 year mortality. The best predictors of increased bleeding tendency were the tests performed after protamine administration (T3). At T3, patients characterized as bleeders had significantly lower MEA ASPI (median, 14 vs. 27 AUC, p = 0.004) and ADP test values (median, 22 vs. 41 AUC, p = 0.002) as well as TEM values expressed in maximum clot firmness after 30 min (MCF 30) for ExTEM (53 vs. 56 mm, p = 0.005), HepTEM (48 vs. 52 mm, p = 0.003) and FibTEM (8 vs. 11 mm, p < 0.001) test. 24 h CTO inversely correlated with both the MEA (ASPI test: r = -0.236, p = 0.004; ADP test: r = -0.299, p < 0.001), and TEM MCF 30 (ExTEM: r = -0.295, p < 0.001; HepTEM: -0.329, p < 0.001; FibTEM: -0.377, p < 0.001) test values. Our study showed that MEA and TEM are useful methods for prediction of excessive bleeding after ECS. In order to prevent excessive postoperative CTO, hemostatic interventions with timely and targeted blood component therapy according to MEA and TEM results should be considered. PMID:23341179

  7. Revised ESC/ESA Guidelines on non-cardiac surgery: cardiovascular assessment and management. Implications for preoperative clinical evaluation.

    PubMed

    Guarracino, F; Baldassarri, R; Priebe, H J

    2015-02-01

    Each year, an increasing number of elderly patients with cardiovascular disease undergoing non-cardiac surgery require careful perioperative management to minimize the perioperative risk. Perioperative cardiovascular complications are the strongest predictors of morbidity and mortality after major non-cardiac surgery. A Joint Task Force of the European Society of Cardiology (ESC) and the European Society of Anaesthesiology (ESA) has recently published revised Guidelines on the perioperative cardiovascular management of patients scheduled to undergo non-cardiac surgery, which represent the official position of the ESC and ESA on various aspects of perioperative cardiac care. According to the Guidelines effective perioperative cardiac management includes preoperative risk stratification based on preoperative assessment of functional capacity, type of surgery, cardiac risk factors, and cardiovascular function. The ESC/ESA Guidelines discourage indiscriminate routine preoperative cardiac testing, because it is time- and cost-consuming, resource-limiting, and does not improve perioperative outcome. They rather emphasize the importance of individualized preoperative cardiac evaluation and the cooperation between anesthesiologists and cardiologists. We summarize the relevant changes of the 2014 Guidelines as compared to the previous ones, with particular emphasis on preoperative cardiac testing. PMID:25384693

  8. A Simplified and Rapid Screening Assay using Zebrafish to Assess Cardiac Effects of Air Pollution-derived Particulate Matter

    EPA Science Inventory

    Comparative toxicity assessment of particulate matter (PM) from different sources will potentially inform the understanding of regional differences in PM-induced cardiac health effects by identifying PM sources linked to highest potency components. Conventional low-throughput in...

  9. Validation of On-Orbit Methodology for the Assessment of Cardiac Function and Changes in the Circulating Volume Using Ultrasound and Braslet-M Occlusion Cuffs

    NASA Technical Reports Server (NTRS)

    Hamilton, Douglas; Sargsyan, Ashot E.; Ebert, Douglas; Duncan, Michael; Bogomolov, Valery V.; Alferova, Irina V.; Matveev, Vladimir P.; Dulchavsky, Scott A.

    2010-01-01

    The objective of this joint U.S. - Russian project was the development and validation of an in-flight methodology to assess a number of cardiac and vascular parameters associated with circulating volume and its manipulation in long-duration space flight. Responses to modified Valsalva and Mueller maneuvers were measured by cardiac and vascular ultrasound (US) before, during, and after temporary volume reduction by means of Braslet-M thigh occlusion cuffs (Russia). Materials and Methods: The study protocol was conducted in 14 sessions on 9 ISS crewmembers, with an average exposure to microgravity of 122 days. Baseline cardiovascular measurements were taken by echocardiography in multiple modes (including tissue Doppler of both ventricles) and femoral and jugular vein imaging on the International Space Station (ISS). The Braslet devices were then applied and measurements were repeated after >10 minutes. The cuffs were then released and the hemodynamic recovery process was monitored. Modified Valsalva and Mueller maneuvers were used throughout the protocol. All US data were acquired by the HDI-5000 ultrasound system aboard the ISS (ATL/Philips, USA) during remotely guided sessions. The study protocol, including the use of Braslet-M for this purpose, was approved by the ISS Human Research Multilateral Review Board (HRMRB). Results: The effects of fluid sequestration on a number of echocardiographic and vascular parameters were readily detectable by in-flight US, as were responses to respiratory maneuvers. The overall volume status assessment methodology appears to be valid and practical, with a decrease in left heart lateral E (tissue Doppler) as one of the most reliable measures. Increase in the femoral vein cross-sectional areas was consistently observed with Braslet application. Other significant differences and trends within the extensive cardiovascular data were also observed. (Decreased - RV and LV preload indices, Cardiac Output, LV E all maneuvers, LV Stroke Volume). Conclusions: This Study: 1) Addressed specific aspects of operational space medicine and space physiology, including assessment of circulating volume disturbances 2) Expanded the applications of diagnostic ultrasound imaging and Doppler techniques in microgravity. 3) Used respiratory maneuvers against the background of acute circulating volume manipulations which appear to enhance our ability to noninvasively detect volume-dependency in a number of cardiac and vascular parameters. 4) Determined that Tei index is not clinically changed therefore contractility not altered in the face of reduced preload. 5) Determined that increased Femoral Vein Area indicating blood being sequestered in lower extremities correlates with reduced preload and cardiac output. 6) That Braslet may be the only feasible means of acutely treating high pressure pulmonary edema in reduced gravity environments.

  10. Cardiac activity in marine invertebrates in response to pollutants: Automated interpulse duration assessment

    SciTech Connect

    Lundebye, A.K.; Curtis, T.; Depledge, M.H.

    1995-12-31

    The updated method of the Computer-Aided Physiological Monitoring (CAPMON) system was used to study the effects of copper exposure on cardiac activity in the shore crab (Carcinus maenas) and the common mussel (Mytilus edulis). This new Automated Interpulse Duration Assessment (AIDA) system measures the time interval between heart beats, and was found to be a more sensitive tool for evaluating cardiac responses to pollutant exposure than other techniques. In addition to information regarding heart rate, also obtained by the CAPMON system (as beats per minute), the new system enables frequency distribution analysis of interpulse duration. An experiment involving C. maenas examined the effects of short term (24 h) and chronic exposure (4 weeks) to copper concentrations 0, 0.2, 0.4, 0.6 and 0.8 mgl{sup {minus}1} Cu. Subsequent recovery (6 weeks) of cardiac activity was also examined. In a second experiment mussels were exposed to one of five copper concentrations (in the range of 0--0.1 mgl{sup {minus}1} Cu) and `normal` cardiac activity was compared with activity after copper exposure. A dose-response relationship was established between copper concentration and heart rate in crabs. The control group had the longest mean inter-pulse duration, and mean interpulse duration decreased in a concentration-dependent manner for the copper treatments, reflecting an increase in heart rate. Distribution of interpulse duration changed from a variable, rather wide distribution in control crabs, to a sharp-peaked normal distribution in exposed crabs. Results after 4 weeks exposure were not significantly different from those found after 24 h. Return to normal cardiac activity was evident after a 6 week `recovery` period. Results from the mussel experiment showed burst activity followed by a decline in heart rate in response to copper exposure.

  11. Nuclear cardiac imaging for the assessment of myocardial viability

    PubMed Central

    Slart, R.H.J.A.; Bax, J.J.; van der Wall, E.E.; van Veldhuisen, D.J.; Jager, P.L.; Dierckx, R.A.

    2005-01-01

    An important aspect of the diagnostic and prognostic work-up of patients with ischaemic cardiomyopathy is the assessment of myocardial viability. Patients with left ventricular dysfunction who have viable myocardium are the patients at highest risk because of the potential for ischaemia but at the same time benefit most from revascularisation. It is important to identify viable myocardium in these patients, and radionuclide myocardial scintigraphy is an excellent tool for this. Single-photon emission computed tomography perfusion scintigraphy (SPECT), whether using 201thallium, 99mTc-sestamibi, or 99mTc- tetrofosmin, in stress and/or rest protocols, has consistently been shown to be an effective modality for identifying myocardial viability and guiding appropriate management. Metabolic and perfusion imaging with positron emission tomography radiotracers frequently adds additional information and is a powerful tool for predicting which patients will have an improved outcome from revascularisation. New techniques in the nuclear cardiology field, such as attenuation corrected SPECT, dual isotope simultaneous acquisition (DISA) SPECT and gated FDG PET are promising and will further improve the detection of myocardial viability. Also the combination of multislice computed tomography scanners with PET opens possibilities of adding coronary calcium scoring and noninvasive coronary angiography to myocardial perfusion imaging and quantification. ImagesFigure 1Figure 2Figure 3 PMID:25696432

  12. Computerized assessment of motion-contaminated calcified plaques in cardiac multidetector CT

    SciTech Connect

    King, Martin; Giger, Maryellen L.; Suzuki, Kenji; Bardo, Dianna M. E.; Greenberg, Brent; Lan Li; Pan Xiaochuan

    2007-12-15

    An automated method for evaluating the image quality of calcified plaques with respect to motion artifacts in noncontrast-enhanced cardiac computed tomography (CT) images is introduced. This method involves using linear regression (LR) and artificial neural network (ANN) regression models for predicting two patient-specific, region-of-interest-specific, reconstruction-specific and temporal phase-specific image quality indices. The first is a plaque motion index, which is derived from the actual trajectory of the calcified plaque and is represented on a continuous scale. The second is an assessability index, which reflects the degree to which a calcified plaque is affected by motion artifacts, and is represented on an ordinal five-point scale. Two sets of assessability indices were provided independently by two radiologists experienced in evaluating cardiac CT images. Inputs for the regression models were selected from 12 features characterizing the dynamic, morphological, and intensity-based properties of the calcified plaques. Whereas LR-velocity (LR-V) used only a single feature (three-dimensional velocity), the LR-multiple (LR-M) and ANN regression models used the same subset of these 12 features selected through stepwise regression. The regression models were parameterized and evaluated using a database of simulated calcified plaque images from the dynamic NCAT phantom involving nine heart rate/multi-sector gating combinations and 40 cardiac phases covering two cardiac cycles. Six calcified plaques were used for the plaque motion indices and three calcified plaques were used for both sets of assessability indices. In one configuration, images from the second cardiac cycle were used for feature selection and regression model parameterization, whereas images from the first cardiac cycle were used for testing. With this configuration, repeated measures concordance correlation coefficients (CCCs) and associated 95% confidence intervals for the LR-V, LR-M, and ANN were 0.817 [0.785, 0.848], 0.894 [0.869, 0.916], and 0.917 [0.892, 0.936] for the plaque motion indices. For the two sets of assessability indices, CCC values for the ANN model were 0.843 [0.791, 0.877] and 0.793 [0.747, 0.828]. These two CCC values were statistically greater than the CCC value of 0.689 [0.648, 0.727], which was obtained by comparing the two sets of assessability indices with each other. These preliminary results suggest that the variabilities of assessability indices provided by regression models can lie within the variabilities of the indices assigned by independent observers. Thus, the potential exists for using regression models and assessability indices for determining optimal phases for cardiac CT image interpretation.

  13. Assessment of diabetic cardiac autonomic neuropathy in type I diabetic mice.

    PubMed

    Yang, Bufan; Chon, Ki H

    2011-01-01

    Diabetic cardiac autonomic neuropathy (DCAN) is one of the most common complications of diabetes. One reason why the pathogenesis of DCAN is unclear is that non-invasive assessment of DCAN in humans and animals has been problematic. To overcome this limitation, we utilized a sensitive and non-invasive method to assess cardiac autonomic dysregulation from ECG records. The method, which could be easily applied to humans, is based on principal dynamic mode (PDM) analysis of heart rate variability (HRV). The method is unique, in that is able to separately identify the activities of the parasympathetic and sympathetic systems without pharmacological intervention. In our study, ECG was measured via telemetry in ten sex- and age-matched (4 month old male) C57 (n=5) and Akita (n=5) mice, a model of insulin-dependent type 1 diabetes. The results indicate significant reduced cardiac autonomic function in the diabetic mice in comparison to the controls. Further, both immunohistochemical and Western blot analyses show a reduction in nerve density in Akita mice as compared to the control mice, thus, corroborating our PDM data analysis of HRV records. PMID:22255842

  14. ICT Expenditures and Education Outputs/Outcomes in Selected Developed Countries: An Assessment of Relative Efficiency

    ERIC Educational Resources Information Center

    Aristovnik, Aleksander

    2013-01-01

    Purpose: The aim of the paper is to review some previous researches examining ICT efficiency and the impact of ICT on educational output/outcome as well as different conceptual and methodological issues related to performance measurement. Design/methodology/approach: This paper adopts a non-parametric methodology, i.e. data envelopment analysis

  15. ICT Expenditures and Education Outputs/Outcomes in Selected Developed Countries: An Assessment of Relative Efficiency

    ERIC Educational Resources Information Center

    Aristovnik, Aleksander

    2013-01-01

    Purpose: The aim of the paper is to review some previous researches examining ICT efficiency and the impact of ICT on educational output/outcome as well as different conceptual and methodological issues related to performance measurement. Design/methodology/approach: This paper adopts a non-parametric methodology, i.e. data envelopment analysis…

  16. Resource and Output Equity as a Mechanism for Assessing Educational Opportunity in Korean Middle School Education

    ERIC Educational Resources Information Center

    Houck, Eric A.; Eom, Moonyoung

    2012-01-01

    Korea is recognized as a high-performing country in international achievement studies; however, many researchers in and outside Korea have been worried about the existing gaps between high-socioeconomic and low-socioeconomic (SES) students in both student achievement and educational resources. We analyzed the resource and output equity of Korean…

  17. Risk Assessment of Mortality Following Intraoperative Cardiac Arrest Using POSSUM and P-POSSUM in Adults Undergoing Non-Cardiac Surgery

    PubMed Central

    Kim, Shin Hyung; Kil, Hae Keum; Kim, Hye Jin

    2015-01-01

    Purpose The Physiological and Operative Severity Score for enUmeration of Mortality and morbidity (POSSUM) and its Portsmouth modification (P-POSSUM) are comprehensive assessment methods for evaluating patient and surgical factors widely used to predict 30-day mortality rates. In this retrospective study, we evaluated the usefulness of POSSUM and P-POSSUM in predicting 30-day mortality after intraoperative cardiac arrests in adult patients undergoing non-cardiac surgery. Materials and Methods Among 190486 patients who underwent anesthesia, 51 experienced intraoperative cardiac arrest as defined in our study protocol. Predicted mortality rates were calculated using POSSUM and P-POSSUM equations and were compared with actual outcomes using exponential and linear analyses. In addition, a receiver operating characteristic curve analysis was undertaken, and area-under-the-curve (AUC) values with confidence intervals (CIs) were calculated for POSSUM and P-POSSUM. Results Among the 51 patients with intraoperative cardiac arrest, 32 (62.7%) died within 30 days postoperatively. The overall predicted 30-day mortality rates using POSSUM and P-POSSUM were 65.5% and 57.5%, respectively. The observed-to-predicted (O:E) ratio for the POSSUM 30-day mortality was 1.07, with no significant difference between the observed and predicted values (χ2=4.794; p=0.779). P-POSSUM predicted mortality equally well, with an O:E ratio of 1.10 (χ2=8.905; p=0.350). AUC values (95% CI) were 0.771 (0.634-0.908) and 0.785 (0.651-0.918) for POSSUM and P-POSSUM, respectively. Conclusion Both POSSUM and P-POSSUM performed well to predict overall 30-day mortality following intraoperative cardiac arrest in adults undergoing non-cardiac surgery at a university teaching hospital in Korea. PMID:26256987

  18. Low-carbon building assessment and multi-scale input-output analysis

    NASA Astrophysics Data System (ADS)

    Chen, G. Q.; Chen, H.; Chen, Z. M.; Zhang, Bo; Shao, L.; Guo, S.; Zhou, S. Y.; Jiang, M. M.

    2011-01-01

    Presented as a low-carbon building evaluation framework in this paper are detailed carbon emission account procedures for the life cycle of buildings in terms of nine stages as building construction, fitment, outdoor facility construction, transportation, operation, waste treatment, property management, demolition, and disposal for buildings, supported by integrated carbon intensity databases based on multi-scale input-output analysis, essential for low-carbon planning, procurement and supply chain design, and logistics management.

  19. On site assessment of cardiac function and neural regulation in amateur half marathon runners

    PubMed Central

    Dalla Vecchia, Laura; Traversi, Egidio; Porta, Alberto; Lucini, Daniela; Pagani, Massimo

    2014-01-01

    Objective Strenuous exercise variably modifies cardiovascular function. Only few data are available on intermediate levels of effort. We therefore planned a study in order to address the hypothesis that a half marathon distance would result in transient changes of cardiac mechanics, neural regulation and biochemical profile suggestive of a complex, integrated adaptation. Methods We enrolled 35 amateur athletes (42±7 years). Supine and standing heart rate variability and a complete echocardiographic evaluation were assessed on site after the completion of a half marathon (postrace) and about 1 month after (baseline). Biochemical tests were also measured postrace. Results Compared to baseline, the postrace left ventricular end-diastolic volume was smaller, peak velocity of E wave was lower, peak velocity of A wave higher, and accordingly the E/A ratio lower. The postrace heart and respiratory rate were higher and variance of RR interval lower, together with a clear shift towards a sympathetic predominance in supine position and a preserved response to orthostasis. At baseline, athletes were characterised by a lower, although still predominant, sympathetic drive with a preserved physiological response to standing. Conclusions Immediately after a half marathon there are clear marks that an elevated sympathetic cardiac drive outlasts the performance, together with decreased left ventricular diastolic volumes and slight modifications of the left ventricular filling pattern without additional signs of diastolic dysfunction or indices of transient left or right ventricular systolic abnormalities. Furthermore, no biochemical indices of any permanent cardiac damage were found. PMID:25332775

  20. Randomised Assessment of Treatment using Panel Assay of Cardiac markers--Contemporary Biomarker Evaluation (RATPAC CBE).

    PubMed Central

    Collinson, P O; Gaze, D C; Thokala, P; Goodacre, S

    2013-01-01

    OBJECTIVES To test the diagnostic accuracy for detecting an acute myocardial infarction (AMI) using highly sensitive troponin assays and a range of new cardiac biomarkers of plaque destabilisation, myocardial ischaemia and necrosis; to test the prognostic accuracy for detecting adverse cardiac events using highly sensitive troponin assays and this range of new cardiac biomarkers; and to estimate the cost-effectiveness of using highly sensitive troponin assays or this range of new cardiac biomarkers instead of an admission and 10- to 12-hour troponin measurement. DESIGN Substudy of the point-of-care arm of the RATPAC (Randomised Assessment of Treatment using Panel Assay of Cardiac markers) trial. SETTING The emergency departments of six hospitals. PARTICIPANTS Prospective admissions with chest pain and a non-diagnostic electrocardiogram randomised to point-of-care assessment or conventional management. INTERVENTIONS Blood samples taken on admission and 90 minutes from admission for measurement of cardiac markers [cardiac troponin I (cTnI), myoglobin and creatine kinase MB isoenzyme (CK-MB)] by point-of-care testing. An additional blood sample was taken at admission and 90 minutes from admission for analysis of high-sensitivity cTnI (two methods) and cardiac troponin T (cTnT), myoglobin, heart-type fatty acid-binding protein (H-FABP), copeptin and B-type natriuretic peptide (NTproBNP). MAIN OUTCOME MEASURES 1. Diagnostic accuracy compared with the universal definition of myocardial infarction utilising laboratory measurements of cardiac troponin performed at the participating sites together with measurements performed in a core laboratory. 2. Ability of biomarker measurements to predict major adverse cardiac events (death, non-fatal AMI, emergency revascularisation or hospitalisation for myocardial ischaemia) at 3 months' follow-up. 3. Comparison of incremental cost per quality-adjusted life-year (QALY) of different biomarker measurement strategies for the diagnosis of myocardial infarction. RESULTS Samples were available from 850 out of 1132 patients enrolled in the study. Measurement of admission myoglobin [area under the curve (AUC) 0.76] and CK-MB (AUC 0.84) was diagnostically inferior and did not add to the diagnostic efficiency of cTnI (AUC 0.90-0.94) or cTnT (AUC 0.92) measurement on admission. Simultaneous measurement of H-FABP and cTnT or cTnI did improve admission diagnostic sensitivity to 0.78-0.92, but only to the same level as that achieved with troponin measured on admission and at 90 minutes from admission (0.78-0.95). Copeptin (AUC 0.62) and NTproBNP (AUC 0.85) measured on admission were not useful as diagnostic markers. As a prognostic marker, troponin measured on admission using a high-sensitivity assay (AUC 0.73-0.83) was equivalent to NTproBNP measurement (AUC 0.77) on admission, but superior to copeptin measurement (AUC 0.58). From modelling, 10-hour troponin measurement is likely to be cost-effective compared with rapid rule-out strategies only if a £30,000 per QALY threshold is used and patients can be discharged as soon as a negative result is available. CONCLUSIONS The measurement of high-sensitivity cardiac troponin is the best single marker in patients presenting with chest pain. Additional measurements of myoglobin or CK-MB are not clinically effective or cost-effective. The optimal timing for measurement of cardiac troponin remains to be defined. Copeptin measurement is not recommended. H-FABP requires further investigation before it can be recommended for simultaneous measurement with high-sensitivity troponin in patients with acute chest pain. TRIAL REGISTRATION ISRCTN37823923. FUNDING This project was funded by the NIHR Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 17, No. 15. See the HTA programme website for further project information. PMID:23597479

  1. Motion corrected LV quantification based on 3D modelling for improved functional assessment in cardiac MRI.

    PubMed

    Liew, Y M; McLaughlin, R A; Chan, B T; Abdul Aziz, Y F; Chee, K H; Ung, N M; Tan, L K; Lai, K W; Ng, S; Lim, E

    2015-04-01

    Cine MRI is a clinical reference standard for the quantitative assessment of cardiac function, but reproducibility is confounded by motion artefacts. We explore the feasibility of a motion corrected 3D left ventricle (LV) quantification method, incorporating multislice image registration into the 3D model reconstruction, to improve reproducibility of 3D LV functional quantification. Multi-breath-hold short-axis and radial long-axis images were acquired from 10 patients and 10 healthy subjects. The proposed framework reduced misalignment between slices to subpixel accuracy (2.88 to 1.21 mm), and improved interstudy reproducibility for 5 important clinical functional measures, i.e. end-diastolic volume, end-systolic volume, ejection fraction, myocardial mass and 3D-sphericity index, as reflected in a reduction in the sample size required to detect statistically significant cardiac changes: a reduction of 21-66%. Our investigation on the optimum registration parameters, including both cardiac time frames and number of long-axis (LA) slices, suggested that a single time frame is adequate for motion correction whereas integrating more LA slices can improve registration and model reconstruction accuracy for improved functional quantification especially on datasets with severe motion artefacts. PMID:25768708

  2. Motion corrected LV quantification based on 3D modelling for improved functional assessment in cardiac MRI

    NASA Astrophysics Data System (ADS)

    Liew, Y. M.; McLaughlin, R. A.; Chan, B. T.; Aziz, Y. F. Abdul; Chee, K. H.; Ung, N. M.; Tan, L. K.; Lai, K. W.; Ng, S.; Lim, E.

    2015-04-01

    Cine MRI is a clinical reference standard for the quantitative assessment of cardiac function, but reproducibility is confounded by motion artefacts. We explore the feasibility of a motion corrected 3D left ventricle (LV) quantification method, incorporating multislice image registration into the 3D model reconstruction, to improve reproducibility of 3D LV functional quantification. Multi-breath-hold short-axis and radial long-axis images were acquired from 10 patients and 10 healthy subjects. The proposed framework reduced misalignment between slices to subpixel accuracy (2.88 to 1.21 mm), and improved interstudy reproducibility for 5 important clinical functional measures, i.e. end-diastolic volume, end-systolic volume, ejection fraction, myocardial mass and 3D-sphericity index, as reflected in a reduction in the sample size required to detect statistically significant cardiac changes: a reduction of 21-66%. Our investigation on the optimum registration parameters, including both cardiac time frames and number of long-axis (LA) slices, suggested that a single time frame is adequate for motion correction whereas integrating more LA slices can improve registration and model reconstruction accuracy for improved functional quantification especially on datasets with severe motion artefacts.

  3. Post-Traumatic Stress Disorder among Cardiac Patients: Prevalence, Risk Factors, and Considerations for Assessment and Treatment

    PubMed Central

    Tulloch, Heather; Greenman, Paul S.; Tassé, Vanessa

    2014-01-01

    There is increasing awareness of the impact of post-traumatic stress disorder (PTSD) on physical health, particularly cardiovascular disease. We review the literature on the role of trauma in the development of cardiovascular risk factors and disease, aftermath of a cardiac event, and risk for recurrence in cardiac patients. We explore possible mechanisms to explain these relationships, as well as appropriate assessment and treatment strategies for this population. Our main conclusion is that screening and referral for appropriate treatments are important given the high prevalence rates of PTSD in cardiac populations and the associated impact on morbidity and mortality. PMID:25545708

  4. A novel cardiac MR chamber volume model for mechanical dyssynchrony assessment

    NASA Astrophysics Data System (ADS)

    Song, Ting; Fung, Maggie; Stainsby, Jeffrey A.; Hood, Maureen N.; Ho, Vincent B.

    2009-02-01

    A novel cardiac chamber volume model is proposed for the assessment of left ventricular mechanical dyssynchrony. The tool is potentially useful for assessment of regional cardiac function and identification of mechanical dyssynchrony on MRI. Dyssynchrony results typically from a contraction delay between one or more individual left ventricular segments, which in turn leads to inefficient ventricular function and ultimately heart failure. Cardiac resynchronization therapy has emerged as an electrical treatment of choice for heart failure patients with dyssynchrony. Prior MRI techniques have relied on assessments of actual cardiac wall changes either using standard cine MR images or specialized pulse sequences. In this abstract, we detail a semi-automated method that evaluates dyssynchrony based on segmental volumetric analysis of the left ventricular (LV) chamber as illustrated on standard cine MR images. Twelve sectors each were chosen for the basal and mid-ventricular slices and 8 sectors were chosen for apical slices for a total of 32 sectors. For each slice (i.e. basal, mid and apical), a systolic dyssynchrony index (SDI) was measured. SDI, a parameter used for 3D echocardiographic analysis of dyssynchrony, was defined as the corrected standard deviation of the time at which minimal volume is reached in each sector. The SDI measurement of a healthy volunteer was 3.54%. In a patient with acute myocardial infarction, the SDI measurements 10.98%, 16.57% and 1.41% for basal, mid-ventricular and apical LV slices, respectively. Based on published 3D echocardiogram reference threshold values, the patient's SDI corresponds to moderate basal dysfunction, severe mid-ventricular dysfunction, and normal apical LV function, which were confirmed on echocardiography. The LV chamber segmental volume analysis model and SDI is feasible using standard cine MR data and may provide more reliable assessment of patients with dyssynchrony especially if the LV myocardium is thin or if the MR images have spatial resolution insufficient for proper resolution of wall thickness-features problematic for dyssynchrony assessment using existing MR techniques.

  5. Statistical Downscaling and Bias Correction of Climate Model Outputs for Climate Change Impact Assessment in the U.S. Northeast

    NASA Technical Reports Server (NTRS)

    Ahmed, Kazi Farzan; Wang, Guiling; Silander, John; Wilson, Adam M.; Allen, Jenica M.; Horton, Radley; Anyah, Richard

    2013-01-01

    Statistical downscaling can be used to efficiently downscale a large number of General Circulation Model (GCM) outputs to a fine temporal and spatial scale. To facilitate regional impact assessments, this study statistically downscales (to 1/8deg spatial resolution) and corrects the bias of daily maximum and minimum temperature and daily precipitation data from six GCMs and four Regional Climate Models (RCMs) for the northeast United States (US) using the Statistical Downscaling and Bias Correction (SDBC) approach. Based on these downscaled data from multiple models, five extreme indices were analyzed for the future climate to quantify future changes of climate extremes. For a subset of models and indices, results based on raw and bias corrected model outputs for the present-day climate were compared with observations, which demonstrated that bias correction is important not only for GCM outputs, but also for RCM outputs. For future climate, bias correction led to a higher level of agreements among the models in predicting the magnitude and capturing the spatial pattern of the extreme climate indices. We found that the incorporation of dynamical downscaling as an intermediate step does not lead to considerable differences in the results of statistical downscaling for the study domain.

  6. Assessment of Cardiac Autonomic Functions in Medical Students With Type D Personality

    PubMed Central

    Panwar, R. Abhilasha Singh

    2016-01-01

    Introduction Type D personality experiences joint occurrence of Negative Affectivity and Social Inhibition. It is an emerging risk factor for cardiovascular disease, with prevalence being 18-53% among cardiac patients. Type D personality people have exaggerated cardiovascular activity mediated by increased sympathetic drive and decreased vagal control of the heart which leads to enhanced risk of hypertension and is an independent risk factor for coronary heart disease. Aim To compare the cardiac autonomic function of Type D and non-Type D students. To compare cardiac autonomic functions among male and female students and students with and without family history of hypertension and coronary artery disease among Type D. To find the most affected test among Type D students. Materials and Methods Thirty Type D and 30 non- Type D medical students were identified by DS14. The Parasympathetic cardiac autonomic tests done assessed Heart Rate response to valsalva manoeuvre, immediate heart rate response to standing and heart rate variation during deep breathing. Sympathetic tests assessed BP response to standing and Sustained Hand Grip. The heart rate and R-R interval measurement were got from lead II of ECG recordings on Polyrite D. Statistical analysis was done using SPSS software. Unpaired student’s t-test was used and p-value <0.05 was considered to be statistically significant. Results Type D students showed slightly decreased parasympathetic activity and increased sympathetic activity when compared to non-Type D students even though there was no statistically significant difference between them. There is a statistically significant decrease in valsalva ratio among females (p<0.01) when compared to males. There is a statistically significant decrease in 30:15 ratio and BP response to handgrip (p<0.05) among students with family history of hypertension and coronary artery disease when compared with students with no family history of coronary artery disease. Valsalva ratio is the most affected test in Type D students. Conclusion Cardiac autonomic functions of Type D personality persons without cardiovascular disease is not different from that of non-Type D. Regular follow up studies over years are required to find if Type D personality is associated with cardiovascular risk in healthy individuals. PMID:27042454

  7. Wavelet transform analysis to assess oscillations in pial artery pulsation at the human cardiac frequency.

    PubMed

    Winklewski, P J; Gruszecki, M; Wolf, J; Swierblewska, E; Kunicka, K; Wszedybyl-Winklewska, M; Guminski, W; Zabulewicz, J; Frydrychowski, A F; Bieniaszewski, L; Narkiewicz, K

    2015-05-01

    Pial artery adjustments to changes in blood pressure (BP) may last only seconds in humans. Using a novel method called near-infrared transillumination backscattering sounding (NIR-T/BSS) that allows for the non-invasive measurement of pial artery pulsation (cc-TQ) in humans, we aimed to assess the relationship between spontaneous oscillations in BP and cc-TQ at frequencies between 0.5 Hz and 5 Hz. We hypothesized that analysis of very short data segments would enable the estimation of changes in the cardiac contribution to the BP vs. cc-TQ relationship during very rapid pial artery adjustments to external stimuli. BP and pial artery oscillations during baseline (70s and 10s signals) and the response to maximal breath-hold apnea were studied in eighteen healthy subjects. The cc-TQ was measured using NIR-T/BSS; cerebral blood flow velocity, the pulsatility index and the resistive index were measured using Doppler ultrasound of the left internal carotid artery; heart rate and beat-to-beat systolic and diastolic blood pressure were recorded using a Finometer; end-tidal CO2 was measured using a medical gas analyzer. Wavelet transform analysis was used to assess the relationship between BP and cc-TQ oscillations. The recordings lasting 10s and representing 10 cycles with a frequency of ~1 Hz provided sufficient accuracy with respect to wavelet coherence and wavelet phase coherence values and yielded similar results to those obtained from approximately 70cycles (70s). A slight but significant decrease in wavelet coherence between augmented BP and cc-TQ oscillations was observed by the end of apnea. Wavelet transform analysis can be used to assess the relationship between BP and cc-TQ oscillations at cardiac frequency using signals intervals as short as 10s. Apnea slightly decreases the contribution of cardiac activity to BP and cc-TQ oscillations. PMID:25804326

  8. [Assessment of the prognosis in patients who remain comatose after resuscitation from cardiac arrest].

    PubMed

    Ramberg, Emilie; Fedder, Anette Marianne; Dyrskog, Stig Eric; Degn, Niels Sanderhoff; Hassager, Christian; Jensen, Reinhold; Kirkegaard, Hans; Weber, Sven; Hoffmann-Petersen, Joachim Torp; Larsen, Niels Heden; Strange, Ditte Gry; Sonne, Morten; Lippert, Freddy K

    2014-06-30

    In Denmark there are around 3,500 unexpected cardiac arrests (CA) out of hospital each year. There is an unknown number of CA in hospitals. The survival rate after CA outside a hospital in Denmark is 10% after 30 days. There are varying data for the neurological outcome in this group of patients. The purpose of this work is to disseminate new knowledge and to help standardizing the treatment in the group of patients who remain comatose after being resuscitated from CA. Assessment of the prognosis for a patient in this group can be made after 72 hours and a multi-modal approach to the patient is required. PMID:25294674

  9. Use of a Three Dimensional Printed Cardiac Model to Assess Suitability for Biventricular Repair.

    PubMed

    Farooqi, Kanwal M; Gonzalez-Lengua, Carlos; Shenoy, Rajesh; Sanz, Javier; Nguyen, Khanh

    2016-05-01

    Three dimensional (3D) printing is rapidly gaining interest in the medical field for use in presurgical planning. We present the case of a seven-year-old boy with double outlet right ventricle who underwent a bidirectional Glenn anastomosis. We used a 3D cardiac model to assess his suitability for a biventricular repair. He underwent a left ventricle-to-aorta baffle with a right ventricle-to-pulmonary artery conduit placement. He did well postoperatively and was discharged home with no evidence of baffle obstruction and good biventricular function. A 3D printed model can provide invaluable intracardiac spatial information in these complex patients. PMID:27009890

  10. Developing a genetic fuzzy system for risk assessment of mortality after cardiac surgery.

    PubMed

    Nouei, Mahyar Taghizadeh; Kamyad, Ali Vahidian; Sarzaeem, MahmoodReza; Ghazalbash, Somayeh

    2014-10-01

    Cardiac events could be taken into account as the leading causes of death throughout the globe. Such events also trigger an undesirable increase in what treatment procedures cost. Despite the giant leaps in technological development in heart surgery, coronary surgery still carries the high risk of the mortality. Besides, there is still a long way ahead to accurately predict and assess the mortality risk. This study is an attempt to develop an expert system for the risk assessment of mortality following the cardiac surgery. The developed system involves three main steps. In the first step, a filtering feature selection method is applied to select the best features. In the second step, an ad hoc data-driven method is utilized to generate the preliminary fuzzy inference system. Finally, a hybrid optimization method is presented to select the optimum subset of the rules. The study relies on 1,811 samples to evaluate the diagnosis performance of the proposed system. The obtained classification accuracy is very promising with regard to other benchmark classification methods including binary logistic regression (LR) and multilayer perceptron neural network (MLP) with the same attributes. The developed system leads to 100% sensitivity and 84.7% specificity, while LR and MLP methods statistically come up with lower figures (65, 78.6 and 65%, 75.8%), respectively. Now, a fuzzy supportive tool can be potentially taken as an alternative for the current mortality risk assessment system that are applied in coronary surgeries, and are chiefly based on crisp database. PMID:25119238

  11. A Delay Vector Variance based Marker for an Output-Only Assessment of Structural Changes in Tension Leg Platforms

    NASA Astrophysics Data System (ADS)

    Jaksic, V.; Wright, C.; Mandic, D. P.; Murphy, J.; Pakrashi, V.

    2015-07-01

    Although aspects of power generation of many offshore renewable devices are well understood, their dynamic responses under high wind and wave conditions are still to be investigated to a great detail. Output only statistical markers are important for these offshore devices, since access to the device is limited and information about the exposure conditions and the true behaviour of the devices are generally partial, limited, and vague or even absent. The markers can summarise and characterise the behaviour of these devices from their dynamic response available as time series data. The behaviour may be linear or nonlinear and consequently a marker that can track the changes in structural situations can be quite important. These markers can then be helpful in assessing the current condition of the structure and can indicate possible intervention, monitoring or assessment. This paper considers a Delay Vector Variance based marker for changes in a tension leg platform tested in an ocean wave basin for structural changes brought about by single column dampers. The approach is based on dynamic outputs of the device alone and is based on the estimation of the nonlinearity of the output signal. The advantages of the selected marker and its response with changing structural properties are discussed. The marker is observed to be important for monitoring the as- deployed structural condition and is sensitive to changes in such conditions. Influence of exposure conditions of wave loading is also discussed in this study based only on experimental data.

  12. High-fat diet induces cardiac remodelling and dysfunction: assessment of the role played by SIRT3 loss

    PubMed Central

    Zeng, Heng; Vaka, Venkata Ramana; He, Xiaochen; Booz, George W; Chen, Jian-Xiong

    2015-01-01

    Mitochondrial dysfunction plays an important role in obesity-induced cardiac impairment. SIRT3 is a mitochondrial protein associated with increased human life span and metabolism. This study investigated the functional role of SIRT3 in obesity-induced cardiac dysfunction. Wild-type (WT) and SIRT3 knockout (KO) mice were fed a normal diet (ND) or high-fat diet (HFD) for 16 weeks. Body weight, fasting glucose levels, reactive oxygen species (ROS) levels, myocardial capillary density, cardiac function and expression of hypoxia-inducible factor (HIF)-1α/-2α were assessed. HFD resulted in a significant reduction in SIRT3 expression in the heart. Both HFD and SIRT3 KO mice showed increased ROS formation, impaired HIF signalling and reduced capillary density in the heart. HFD induced cardiac hypertrophy and impaired cardiac function. SIRT3 KO mice fed HFD showed greater ROS production and a further reduction in cardiac function compared to SIRT3 KO mice on ND. Thus, the adverse effects of HFD on cardiac function were not attributable to SIRT3 loss alone. However, HFD did not further reduce capillary density in SIRT3 KO hearts, implicating SIRT3 loss in HFD-induced capillary rarefaction. Our study demonstrates the importance of SIRT3 in preserving heart function and capillary density in the setting of obesity. Thus, SIRT3 may be a potential therapeutic target for obesity-induced heart failure. PMID:25782072

  13. High-fat diet induces cardiac remodelling and dysfunction: assessment of the role played by SIRT3 loss.

    PubMed

    Zeng, Heng; Vaka, Venkata Ramana; He, Xiaochen; Booz, George W; Chen, Jian-Xiong

    2015-08-01

    Mitochondrial dysfunction plays an important role in obesity-induced cardiac impairment. SIRT3 is a mitochondrial protein associated with increased human life span and metabolism. This study investigated the functional role of SIRT3 in obesity-induced cardiac dysfunction. Wild-type (WT) and SIRT3 knockout (KO) mice were fed a normal diet (ND) or high-fat diet (HFD) for 16 weeks. Body weight, fasting glucose levels, reactive oxygen species (ROS) levels, myocardial capillary density, cardiac function and expression of hypoxia-inducible factor (HIF)-1α/-2α were assessed. HFD resulted in a significant reduction in SIRT3 expression in the heart. Both HFD and SIRT3 KO mice showed increased ROS formation, impaired HIF signalling and reduced capillary density in the heart. HFD induced cardiac hypertrophy and impaired cardiac function. SIRT3 KO mice fed HFD showed greater ROS production and a further reduction in cardiac function compared to SIRT3 KO mice on ND. Thus, the adverse effects of HFD on cardiac function were not attributable to SIRT3 loss alone. However, HFD did not further reduce capillary density in SIRT3 KO hearts, implicating SIRT3 loss in HFD-induced capillary rarefaction. Our study demonstrates the importance of SIRT3 in preserving heart function and capillary density in the setting of obesity. Thus, SIRT3 may be a potential therapeutic target for obesity-induced heart failure. PMID:25782072

  14. Functional Cardiac Magnetic Resonance Imaging (MRI) in the Assessment of Myocardial Viability and Perfusion

    PubMed Central

    2003-01-01

    Executive Summary Objective The objective of this health technology policy assessment was to determine the effectiveness safety and cost-effectiveness of using functional cardiac magnetic resonance imaging (MRI) for the assessment of myocardial viability and perfusion in patients with coronary artery disease and left ventricular dysfunction. Results Functional MRI has become increasingly investigated as a noninvasive method for assessing myocardial viability and perfusion. Most patients in the published literature have mild to moderate impaired LV function. It is possible that the severity of LV dysfunction may be an important factor that can alter the diagnostic accuracy of imaging techniques. There is some evidence of comparable or better performance of functional cardiac MRI for the assessment of myocardial viability and perfusion compared with other imaging techniques. However limitations to most of the studies included: Functional cardiac MRI studies that assess myocardial viability and perfusion have had small sample sizes. Some studies assessed myocardial viability/perfusion in patients who had already undergone revascularization, or excluded patients with a prior MI (Schwitter et al., 2001). Lack of explicit detail of patient recruitment. Patients with LVEF >35%. Interstudy variability in post MI imaging time(including acute or chronic MI), when patients with a prior MI were included. Poor interobserver agreement (kappa statistic) in the interpretation of the results. Traditionally, 0.80 is considered “good”. Cardiac MRI measurement of myocardial perfusion to as an adjunct tool to help diagnose CAD (prior to a definitive coronary angiography) has also been examined in some studies, with methodological limitations, yielding comparable results. Many studies examining myocardial viability and perfusion report on the accuracy of imaging methods with limited data on long-term patient outcome and management. Kim et al. (2000) revealed that the transmural extent of hyperenhancement was significantly related to the likelihood of improvement in contractility after revascularization. However, the LVEF in the patient population was 43% prior to revascularization. It is important to know whether the technique has the same degree of accuracy in patients who have more severe LV dysfunction and who would most benefit from an assessment of myocardial viability. “Substantial” viability used as a measure of a patient’s ability to recover after revascularization has not been definitively reported (how much viability is enough?). Patients with severe LV dysfunction are more likely to have mixtures of surviving myocardium, including normal, infarcted, stunned and hibernating myocardium (Cowley et al., 1999). This may lead to a lack of homogeneity of response to testing and to revascularization and contribute to inter- and intra-study differences. There is a need for a large prospective study with adequate follow-up time for patients with CAD and LV dysfunction (LVEF<35%) comparing MRI and an alternate imaging technique. There is some evidence that MRI has comparable sensitivity, specificity and accuracy to PET for determining myocardial viability. However, there is a lack of evidence comparing the accuracy of these two techniques to predict LV function recovery. In addition, some studies refer to PET as the gold standard for the assessment of myocardial viability. Therefore, PET may be an ideal noninvasive imaging comparator to MRI for a prospective study with follow-up. To date, there is a lack of cost-effectiveness analyses (or any economic analyses) of functional cardiac MRI versus an alternate noninvasive imaging method for the assessment of myocardial viability/perfusion. Conclusion There is some evidence that the accuracy of functional cardiac MRI compares favourably with alternate imaging techniques for the assessment of myocardial viability and perfusion. There is insufficient evidence whether functional cardiac MRI can better select which patients [who have CAD and severe LV dysfunction (LVEF <35%)] may benefit from revascularization compared with an alternate noninvasive imaging technology. There is insufficient evidence whether functional cardiac MRI can better select which patients should proceed to invasive coronary angiography for the definitive diagnosis of CAD, compared with an alternate noninvasive imaging technology. There is a need for a large prospective (potentially multicentre) study with adequate follow-up time for patients with CAD and LV dysfunction (LVEF<35%) comparing MRI and PET. Since longer follow-up time may be associated with restenosis or graft occlusion, it has been suggested to have serial measurements after revascularization (Cowley et al., 1999). PMID:23074446

  15. Is cardiac magnetic resonance imaging as accurate as echocardiography in the assessment of aortic valve stenosis?

    PubMed

    Wong, Sophia; Spina, Roberto; Toemoe, Sianne; Dhital, Kumud

    2016-04-01

    A best evidence topic was written according to a structured protocol. The question addressed was: is cardiac magnetic resonance (CMR) imaging as accurate as echocardiography in the assessment of aortic valve stenosis? Altogether 239 papers were found using the reported search. Only 12 demonstrated the best evidence to answer the clinical question. Nine of these 12 papers found CMR to correlate well with transthoracic echocardiography (TTE) or transoesophageal echocardiography (TOE) in the evaluation of aortic valve stenosis. When aortic valve areas were measured with cardiac tomography (CT) or cardiac catheterization (CC), four papers found CMR to be more accurate than TTE. Eight of 12 papers found CMR to have excellent reliability and reproducibility, as demonstrated by the low inter- and intraobserver variability. Four papers did not estimate intra- or interobserver variability. One paper noted a sensitivity and specificity of 96 and 100%, respectively, when using CMR to detect severe aortic stenosis (AS) that had been diagnosed during CC. A second paper noted a lower sensitivity and specificity of 78 and 89%, respectively, but this was still better than the sensitivities and specificities found when using TOE or TTE to detect severe AS, as noted on CC. We conclude that current evidence finds echocardiography and CMR to be equally reliable in assessing aortic stenosis. CMR has better inter- and intraobserver reliability and demonstrates an advantage over echocardiography in the detection of severe AS with greater specificity and sensitivity. The final choice, however, is as likely to be influenced by the availability of magnetic resonance imaging and expertise in interpreting the results as by accuracy and reliability. PMID:26718319

  16. Assessment of cardiac single-photon emission computed tomography performance using a scanning linear observer

    SciTech Connect

    Lee, Chih-Jie; Kupinski, Matthew A.; Volokh, Lana

    2013-01-15

    Purpose: Single-photon emission computed tomography (SPECT) is widely used to detect myocardial ischemia and myocardial infarction. It is important to assess and compare different SPECT system designs in order to achieve the highest detectability of cardiac defects. Methods: Whitaker et al.'s study ['Estimating random signal parameters from noisy images with nuisance parameters: linear and scanning-linear methods,' Opt. Express 16(11), 8150-8173 (2008)] on the scanning linear observer (SLO) shows that the SLO can be used to estimate the location and size of signals. One major advantage of the SLO is that it can be used with projection data rather than with reconstruction data. Thus, this observer model assesses the overall hardware performance independent of any reconstruction algorithm. In addition, the computation time of image quality studies is significantly reduced. In this study, three systems based on the design of the GE cadmium zinc telluride-based dedicated cardiac SPECT camera Discovery 530c were assessed. This design, which is officially named the Alcyone Technology: Discovery NM 530c, was commercialized in August, 2009. The three systems, GE27, GE19, and GE13, contain 27, 19, and 13 detectors, respectively. Clinically, a human heart can be virtually segmented into three coronary artery territories: the left-anterior descending artery, left-circumflex artery, and right coronary artery. One of the most important functions of a cardiac SPECT system is to produce images from which a radiologist can accurately predict in which territory the defect exists [http://www.asnc.org/media/PDFs/PPReporting081511.pdf, Guideline from American Society of Nuclear Cardiology]. A good estimation of the extent of the defect from the projection images is also very helpful for determining the seriousness of the myocardial ischemia. In this study, both the location and extent of defects were estimated by the SLO, and the system performance was assessed by localization receiver operating characteristic (LROC) [P. Khurd and G. Gindi, 'Decision strategies maximizing the area under the LROC curve,' Proc. SPIE 5749, 150-161 (2005)] or estimation receiver operating characteristic (EROC) [E. Clarkson, 'Estimation receiver operating characteristic curve and ideal observers for combined detection/estimation tasks,' J. Opt. Soc. Am. A 24, B91-B98 (2007)] curves. Results: The area under the LROC/EROC curve (AULC/AUEC) and the true positive fraction (TPF) at a specific false positive fraction (FPF) can be treated as the figures of merit. For radii estimation with a 1 mm tolerance, the AUEC values of the GE27, GE19, and GE13 systems are 0.8545, 0.8488, and 0.8329, and the TPF at FPF = 5% are 77.1%, 76.46%, and 73.55%, respectively. The assessment of all three systems revealed that the GE19 system yields estimated information and cardiac defect detectability very close to those of the GE27 system while using eight fewer detectors. Thus, 30% of the expensive detector units can be removed with confidence. Conclusions: As the results show, a combination of the SLO and LROC/EROC curves can determine the configuration that yields the most relevant estimation/detection information. Thus, this is a useful method for assessing cardiac SPECT systems.

  17. Assessment of cardiac single-photon emission computed tomography performance using a scanning linear observer

    PubMed Central

    Lee, Chih-Jie; Kupinski, Matthew A.; Volokh, Lana

    2013-01-01

    Purpose: Single-photon emission computed tomography (SPECT) is widely used to detect myocardial ischemia and myocardial infarction. It is important to assess and compare different SPECT system designs in order to achieve the highest detectability of cardiac defects. Methods:Whitaker ’s study [“Estimating random signal parameters from noisy images with nuisance parameters: linear and scanning-linear methods,” Opt. Express 16(11), 8150–8173 (2008)]10.1364/OE.16.008150 on the scanning linear observer (SLO) shows that the SLO can be used to estimate the location and size of signals. One major advantage of the SLO is that it can be used with projection data rather than with reconstruction data. Thus, this observer model assesses the overall hardware performance independent of any reconstruction algorithm. In addition, the computation time of image quality studies is significantly reduced. In this study, three systems based on the design of the GE cadmium zinc telluride-based dedicated cardiac SPECT camera Discovery 530c were assessed. This design, which is officially named the Alcyone Technology: Discovery NM 530c, was commercialized in August, 2009. The three systems, GE27, GE19, and GE13, contain 27, 19, and 13 detectors, respectively. Clinically, a human heart can be virtually segmented into three coronary artery territories: the left-anterior descending artery, left-circumflex artery, and right coronary artery. One of the most important functions of a cardiac SPECT system is to produce images from which a radiologist can accurately predict in which territory the defect exists [http://www.asnc.org/media/PDFs/PPReporting081511.pdf, Guideline from American Society of Nuclear Cardiology]. A good estimation of the extent of the defect from the projection images is also very helpful for determining the seriousness of the myocardial ischemia. In this study, both the location and extent of defects were estimated by the SLO, and the system performance was assessed by localization receiver operating characteristic (LROC) [P. Khurd and G. Gindi, “Decision strategies maximizing the area under the LROC curve,” Proc. SPIE 5749, 150–161 (2005)]10.1117/12.595915 or estimation receiver operating characteristic (EROC) [E. Clarkson, “Estimation receiver operating characteristic curve and ideal observers for combined detection/estimation tasks,” J. Opt. Soc. Am. A 24, B91–B98 (2007)]10.1364/JOSAA.24.000B91 curves. Results: The area under the LROC/EROC curve (AULC/AUEC) and the true positive fraction (TPF) at a specific false positive fraction (FPF) can be treated as the figures of merit. For radii estimation with a 1 mm tolerance, the AUEC values of the GE27, GE19, and GE13 systems are 0.8545, 0.8488, and 0.8329, and the TPF at FPF = 5% are 77.1%, 76.46%, and 73.55%, respectively. The assessment of all three systems revealed that the GE19 system yields estimated information and cardiac defect detectability very close to those of the GE27 system while using eight fewer detectors. Thus, 30% of the expensive detector units can be removed with confidence. Conclusions: As the results show, a combination of the SLO and LROC/EROC curves can determine the configuration that yields the most relevant estimation/detection information. Thus, this is a useful method for assessing cardiac SPECT systems. PMID:23298097

  18. Assessment of adult body composition using bioelectrical impedance: comparison of researcher calculated to machine outputted values

    PubMed Central

    Franco-Villoria, Maria; Wright, Charlotte M; McColl, John H; Sherriff, Andrea; Pearce, Mark S

    2016-01-01

    Objectives To explore the usefulness of Bioelectrical Impedance Analysis (BIA) for general use by identifying best-evidenced formulae to calculate lean and fat mass, comparing these to historical gold standard data and comparing these results with machine-generated output. In addition, we explored how to best to adjust lean and fat estimates for height and how these overlapped with body mass index (BMI). Design Cross-sectional observational study within population representative cohort study. Setting Urban community, North East England Participants Sample of 506 mothers of children aged 7–8 years, mean age 36.3 years. Methods Participants were measured at a home visit using a portable height measure and leg-to-leg BIA machine (Tanita TBF-300MA). Measures Height, weight, bioelectrical impedance (BIA). Outcome measures Lean and fat mass calculated using best-evidenced published formulae as well as machine-calculated lean and fat mass data. Results Estimates of lean mass were similar to historical results using gold standard methods. When compared with the machine-generated values, there were wide limits of agreement for fat mass and a large relative bias for lean that varied with size. Lean and fat residuals adjusted for height differed little from indices of lean (or fat)/height2. Of 112 women with BMI >30 kg/m2, 100 (91%) also had high fat, but of the 16 with low BMI (<19 kg/m2) only 5 (31%) also had low fat. Conclusions Lean and fat mass calculated from BIA using published formulae produces plausible values and demonstrate good concordance between high BMI and high fat, but these differ substantially from the machine-generated values. Bioelectrical impedance can supply a robust and useful field measure of body composition, so long as the machine-generated output is not used. PMID:26743700

  19. Cardiac gated ventilation

    NASA Astrophysics Data System (ADS)

    Hanson, C. William, III; Hoffman, Eric A.

    1995-05-01

    There are several theoretic advantages to synchronizing positive pressure breaths with the cardiac cycle, including the potential for improving distribution of pulmonary and myocardial blood flow and enhancing cardiac output. We evaluated the effects of synchronizing respiration to the cardiac cycle using a programmable ventilator and electron beam CT (EBCT) scanning. The hearts of anesthetized dogs were imaged during cardiac gated respiration with a 50msec scan aperture. Multislice, short axis, dynamic image data sets spanning the apex to base of the left ventricle were evaluated to determine the volume of the left ventricular chamber at end-diastole and end-systole during apnea, systolic and diastolic cardiac gating. We observed an increase in cardiac output of up to 30% with inspiration gated to the systolic phase of the cardiac cycle in a nonfailing model of the heart.

  20. Animal welfare assessment at slaughter in Europe: moving from inputs to outputs.

    PubMed

    Velarde, Antonio; Dalmau, Antoni

    2012-11-01

    Producers, retailers and other food chain actors increasingly recognize that consumer concerns for good animal welfare represent a business opportunity that could be profitably incorporated into their commercial strategies. Therefore, during the last decade, numerous trade groups (producers, processors, retailers and restaurant chains) have developed certification systems with their suppliers which include elements of animal welfare. The Welfare Quality® project has developed an integrated and standardised welfare assessment system based on twelve welfare criteria grouped into four main principles (good feeding, good housing, good health and appropriate behaviour) according to how they are experienced by animals. One of the innovations of the Welfare Quality® assessment system is that it focuses more on outcome measures (e.g. directly related to animal body condition, health aspects, injuries, behaviour, etc.). This paper has the objective to discuss the rationale behind the welfare assessment and to describe the Welfare Quality® assessment of pigs and cattle at the slaughterhouse. PMID:22551869

  1. Prospective coronary angioscopy assessment of allograft coronary artery disease in human cardiac transplant recipients

    NASA Astrophysics Data System (ADS)

    Jain, Ashit; Ventura, Hector O.; Collins, Tyrone J.; Ramee, Stephen R.; White, Christopher J.

    1993-09-01

    Annual angiographic assessment to determine the presence or progression of allograft coronary artery disease (CAD) has been unable to modify the natural history of this disease. Coronary angioscopy is a sensitive method to detect the early presence of coronary artery disease and in a retrospective analysis severity of CAD by angioscopy correlated with the time since transplantation. The purpose of this study was to prospectively evaluate progression of coronary artery disease over a one year period in 40 cardiac transplant recipients. The progression of coronary artery disease as assessed by angioscopy is directly related to time after transplantation and therefore angioscopy may be the method of choice for detection and evaluation of therapeutic regimens to control allograft coronary artery disease.

  2. Noninvasive measurement of cardiac performance in recovery from exercise in heart failure patients

    PubMed Central

    Myers, Jonathan N; Gujja, Pradeep; Neelagaru, Suresh; Hsu, Leon; Burkhoff, Daniel

    2011-01-01

    OBJECTIVE: To examine the association between cardiac performance during recovery and the severity of heart failure, as determined by clinical and cardiopulmonary exercise test responses. METHODS: As part of a retrospective cohort study, 46 heart failure patients and 13 normal subjects underwent cardiopulmonary exercise testing while cardiac output was measured using a noninvasive device. Cardiac output in recovery was expressed as the slope of a single exponential relationship between cardiac output and time; the recovery-time constant was assessed in relation to indices of cardiac function, along with clinical, functional, and cardiopulmonary exercise responses. RESULTS: The recovery time constant was delayed in patients with heart failure compared with normal subjects (296.7±238 vs. 110.1±27 seconds, p <0.01), and the slope of the decline of cardiac output in recovery was steeper in normal subjects compared with heart failure patients (p<0.001). The slope of the decline in cardiac output recovery was inversely related to peak VO2 (r = -0.72, p<0.001) and directly related to the VE/VCO2 slope (r = 0.57, p<0.001). Heart failure patients with abnormal recovery time constants had lower peak VO2, lower VO2 at the ventilatory threshold, lower peak cardiac output, and a heightened VE/VCO2 slope during exercise. CONCLUSIONS: Impaired cardiac output recovery kinetics can identify heart failure patients with more severe disease, lower exercise capacity, and inefficient ventilation. Estimating cardiac output in recovery from exercise may provide added insight into the cardiovascular status of patients with heart failure. PMID:21655761

  3. A Study of Underprepared Students at One Community College: Assessing the Impact of Student and Institutional Input, Environmental, and Output Variables on Student Success. ASHE Annual Meeting Paper.

    ERIC Educational Resources Information Center

    Long, Patricia N.; Amey, Marilyn J.

    This study identified input, environmental, and output variables accounting for differences between successful and unsuccessful groups of underprepared students at Johnson County Community College (Kansas). The study applied an adaptation of Alexander Astin's input-environment-output model of assessing student and institutional effectiveness.…

  4. Cardiac index assessment using bioreactance in patients undergoing cytoreductive surgery in ovarian carcinoma.

    PubMed

    Kober, David; Trepte, Constantin; Petzoldt, Martin; Nitzschke, Rainer; Herich, Lena; Reuter, Daniel A; Haas, Sebastian

    2013-12-01

    This clinical study compared the cardiac index (CI) assessed by the totally non-invasive method of bioreactance (CIBR) (NICOM™, Cheetah Medical, Vancouver, USA) to transpulmonary thermodilution (CITD) during cytoreductive surgery in ovarian carcinoma. The hypothesis was that CI could be assessed by bioreactance in an accurate and precise manner including accurate trending ability when compared to transpulmonary thermodilution. In 15 patients CIBR and CITD were assessed after induction of anesthesia, after opening of the peritoneum, hourly during the operative procedure, and 30 min after extubation. Trending ability was assessed between the described timepoints. In total 84 points of measurement were analyzed. Concordance correlation coefficient for repeated measures correlating the CIBR and CITD was 0.32. Bias was 0.26 l/min/m(2) (limits of agreement -1.39 and 1.92 l/min/m(2)). The percentage error was 50.7 %. Trending ability quantified by the mean of angles θ which are made by the ΔCI vector and the line of identity (y = x) showed a value for CIBR of θ = 23.4°. CI assessment by bioreactance showed acceptable accuracy and trending ability. However, its precision was poor. Therefore, CI measurement can not be solely based on bioreactance in patients undergoing cytoreductive surgery in ovarian carcinoma. PMID:23689837

  5. An Adaptive Regional Input-Output Model and its Application to the Assessment of the Economic Cost of Katrina

    NASA Astrophysics Data System (ADS)

    Hallegatte, S.

    2006-12-01

    Recent events, especially natural disasters, have raised concerns about the response of local economies to large exogenous shocks. Clearly, our ability to assess the total economic costs of large-scale events like the Katrina's landfall is very poor, and numerous questions needs to be investigated. Among them, the taking into account of complex interactions within the economic system --- between economic sectors or regions --- is the topic of intense research. Several studies have approached these issues using Input-Output models, which are powerful tools to assess how a shock, on one or several sectors, propagate into the economy through intermediate consumption and demand. These models, however, have two main short-comings. First, since they do not take into account productive capacity, they cannot assess the consequence of a shock on the supply-side. Second, they do not allow for flexibility in the economic system in that producers and consumers cannot respond to a lack in input. The presentation will describe an adaptive regional input-output model, which aims at answering the previous concerns through the introduction of an hybrid modelling methodology. This model takes into account economic propagations through both intermediate demands and production shortages, and also represents the response of economic agents facing production shortages. An application of this model to the evaluation of the economic cost of Katrina will be demonstrated, highlighting both modelling and data issues. Also, beyond a simple "best-guess" assessment, systematic sensitivity analyses will be presented, allowing for an evaluation of the accuracy one can expect from such a model.

  6. Scintigraphic assessment of cardiac adrenergic innervation in patients with essential hypertension

    SciTech Connect

    Fujiwara, Y.; Hamada, M.; Shigematsu, Y.; Sumimoto, T.; Hamamoto, K.; Hiwada, K. )

    1991-01-01

    To assess the regional cardiac adrenergic innervation in patients with essential hypertension (EHT), simultaneous iodine-123 metaiodobenzylguanidine ((123I)MIBG) and thallium-201 (201Tl) myocardial imagings were performed in five patients with EHT, seven patients with hypertrophic cardiomyopathy (HCM), and seven normal subjects. Short axial images at rest were divided into five segments: anterior, septal, posterior, lateral, and apical segments. Percent regional uptake (%RU) of 201Tl except the septal segment in patients with EHT showed no significant difference. However, the %RU of (123I)MIBG at posterior, lateral, and apical segments was significantly lower than that at anterior and septal segments in EHT. This intraimage heterogeneity of (123I)MIBG was also observed in HCM. These results suggest that there is a difference in regional adrenergic innervation of the left ventricle with myocardial hypertrophy.

  7. [Cardiac tamponade following sternal puncture. Usefulness of ultrasound focussed assessment with sonography for trauma].

    PubMed

    Magaldi, M; Hervías, A; Perelló, L; Fontanals, J

    2014-03-01

    One of the aims of the medical profession is to be able to detect complications in patients during diagnostic tests and treatments. The early diagnosis of these complications can prevent a fatal outcome. The diagnosis is often based on clinical symptoms and supported by complementary tests. Diagnostic tests have been developed in the last few years that are rapid and easy to use, as well as being cost effective and minimally invasive. Focussed assessment with sonography for trauma ultrasound (echo-FAST) was introduced in the 1990s in the field of resuscitation as a test for the rapid detection of intra-abdominal and pericardial fluid in multiple injury patients, but its uses in other cases not involving trauma still raise doubts and controversy. A case is presented of a patient subjected to a sternal puncture for a bone marrow aspirate, who had a complication of a secondary cardiac tamponade, which was diagnosed early using echo-FAST. PMID:23352376

  8. Cardiac magnetic resonance for the assessment of myocardial viability: from pathophysiology to clinical practice.

    PubMed

    Dellegrottaglie, Santo; Guarini, Pasquale; Savarese, Gianluigi; Gambardella, Francesco; Lo Iudice, Francesco; Cirillo, Annapaola; Vitagliano, Alice; Formisano, Tiziana; Pellegrino, Angela M; Bossone, Eduardo; Perrone-Filardi, Pasquale

    2013-12-01

    Cardiac magnetic resonance (CMR) is commonly applied for the assessment of myocardial viability in patients with ischemic ventricular dysfunction, and it holds potential advantages over more traditional imaging modalities, including single-photon emission computed tomography (SPECT) and dobutamine stress echocardiography (DSE). CMR-based techniques for viability assessment include the evaluation of transmural extent of the scar using late gadolinium enhancement (LGE) images, the evaluation of end-diastolic wall thickness from resting cine images and the study of inotropic reserve during low-dose dobutamine infusion. During the past decade, the diffusion of the use of CMR for viability assessment confirmed the clinical strengths of this modality and, at the same time, helped to use old techniques with an increased level of awareness. With LGE CMR, both viable and nonviable dysfunctional myocardium can be visualized in a single image, allowing a direct quantification of the amount of regional viability, with a significant impact on the estimation of chance for recovery. As well, studies with CMR applied in the setting of ischemic heart disease allowed a better understanding of the best way to apply and interpret other tests for viability evaluation. For instance, it has been demonstrated that the transmural extension of the scar may influence the level of concordance between SPECT and DSE in assessing myocardial viability. The transmural extent of scar on LGE CMR also correlates with the timing of postrevascularization recovery of systolic function, with significant impact on the diagnostic accuracy of any applied imaging modality. PMID:23756415

  9. A Prospective Assessment of the Effect of Aminophylline Therapy on Urine Output and Inflammation in Critically Ill Children

    PubMed Central

    Tamburro, Robert F.; Thomas, Neal J.; Ceneviva, Gary D.; Dettorre, Michael D.; Brummel, Gretchen L.; Lucking, Steven E.

    2014-01-01

    Background: Aminophylline, an established bronchodilator, is also purported to be an effective diuretic and anti-inflammatory agent. However, the data to support these contentions are scant. We conducted a prospective, open-label, single arm, single center study to assess the hypothesis that aminophylline increases urine output and decreases inflammation in critically ill children. Methods: Children less than 18 years of age admitted to the pediatric intensive care unit who were prescribed aminophylline over a 24-h period were eligible for study. The use and dosing of aminophylline was independent of the study and was at the discretion of the clinical team. Data analyzed consisted of demographics, diagnoses, medications, and markers of pulmonary function, renal function, and inflammation. Data were collected at baseline and at 24-h after aminophylline initiation with primary outcomes of change in urine output and inflammatory cytokine concentrations. Results: Thirty-five patients were studied. Urine output increased significantly with aminophylline use [median increase 0.5 mL/kg/h (IQR: −0.3, 1.3), p = 0.05] while blood urea nitrogen and creatinine concentrations remained unchanged. Among patients with elevated C-reactive protein concentrations, levels of both interleukin-6 (IL-6) and IL-10 decreased at 24 h of aminophylline therapy. There were no significant differences in pulmonary compliance or resistance among patients invasively ventilated at both time points. Side effects of aminophylline were detected in 7 of 35 patients. Conclusion: Although no definitive conclusions can be drawn from this study, aminophylline may be a useful diuretic and effective anti-inflammatory medication in critically ill children. Given the incidence of side effects, the small sample size and the uncontrolled study design, further study is needed to inform the appropriate use of aminophylline in these children. PMID:24971305

  10. High-dose interleukin 2-induced myocarditis: can myocardial damage reversibility be assessed by cardiac MRI?

    PubMed

    Chow, Shien; Cove-Smith, Laura; Schmitt, Matthias; Hawkins, Robert

    2014-06-01

    High-dose interleukin 2 (HD-IL2) is one of the therapeutic options for patients with metastatic renal cell carcinoma. In well-selected patients with favorable clinical and pathologic features, it offers impressive response and potential long-term remission. It also has a place for treatment for metastatic malignant melanoma and in adoptive cell therapy. However, it is known for its intensive course and toxicities. Myocarditis is one of the known complications of this treatment and can pose a diagnostic challenge to treating oncologists because of its nonspecific and similar presentation to acute coronary syndrome (ACS). We report 3 short cases of HD-IL2-related myocarditis, which were either missed or misdiagnosed as ACS using conventional assessment but subsequently accurately diagnosed by cardiac magnetic resonant imaging (CMR). We discussed the clinical presentation of these cases and demonstrated the diagnostic advantage of CMR compared with standard investigations including its superior capability to assess myocardial reversibility, which has important short-term and long-term implications. The use of CMR also avoided unnecessary invasive intervention such as coronary angiogram in all 3 patients. These example cases call for effort to conduct prospective research to assess and confirm the utility of CMR, thus informing a more effective management pathway for immune-related myocarditis in HD-IL2 and other cancer immunotherapy. PMID:24810642

  11. Assessment of Cardiac Involvement in Myotonic Muscular Dystrophy by T1 Mapping on Magnetic Resonance Imaging

    PubMed Central

    Turkbey, Evrim B.; Gai, Neville; Lima, João A. C.; van der Geest, Rob J.; Wagner, Kathryn R.; Tomaselli, Gordon F.; Bluemke, David A.; Nazarian, Saman

    2012-01-01

    Background Patients with DM are at risk for atrioventricular block and left ventricular (LV) dysfunction. Non-invasive detection of diffuse myocardial fibrosis may improve disease management in this population. Objective Our aim was to define functional and post-contrast myocardial T1 time cardiac magnetic resonance (CMR) characteristics in myotonic muscular dystrophy (DM) patients. Methods Thirty-three DM patients (24 with type 1 and 9 with type 2) and 13 healthy volunteers underwent CMR for assessment of LV indices and evaluation of diffuse myocardial fibrosis by T1 mapping. The association of myocardial T1 time to ECG abnormalities and LV indices were examined among DM patients. Results DM patients had lower end-diastolic volume index (68.9 vs. 60.3 ml/m2, p=0.045), cardiac index (2.7 vs. 2.33 L/min/m2, p=0.005) and shorter myocardial T1time (394.5 vs. 441.4 ms, p<0.0001), compared to control subjects. Among DM patients, there was a positive association between higher T1 time and LV mass index (2.2 ms longer per gm/m2, p=0.006), LV end-diastolic volume index (1.3 ms longer per ml/m2, p=0.026), filtered QRS duration (1.2 ms longer per unit, p=0.005) and low-amplitude (<40mcV) late-potential duration (0.9 ms longer per unit, p=0.01). Using multivariate random effects regression, each 10 ms increase in myocardial T1 time of type 1 DM patients was independently associated with 1.3 ms increase in longitudinal PR and QRS intervals during follow-up. Conclusion DM is associated with structural alterations on CMR. Post-contrast myocardial T1 time was shorter in DM patients than controls likely reflecting the presence of diffuse myocardial fibrosis. PMID:22710483

  12. Cardiac risk in the treatment of breast cancer: assessment and management

    PubMed Central

    Valachis, Antonis; Nilsson, Cecilia

    2015-01-01

    As the number of long-term breast cancer survivors has increased, the side effects of adjuvant cancer therapy, such as cardiac toxicity, remain clinically important. Although the cardiac toxicity due to anthracyclines, radiotherapy, or trastuzumab is well-documented, several issues need to be clarified and are the subjects of extensive ongoing clinical research. This review summarizes the incidence of cardiac toxicity due to breast cancer adjuvant therapy and highlights the current trends in early detection and management of cardiac toxicities. PMID:25653554

  13. Regional assessment of LV wall in infarcted heart using tagged MRI and cardiac modelling

    NASA Astrophysics Data System (ADS)

    Jahanzad, Zeinab; Miin Liew, Yih; Bilgen, Mehmet; McLaughlin, Robert A.; Onn Leong, Chen; Chee, Kok Han; Aziz, Yang Faridah Abdul; Ung, Ngie Min; Lai, Khin Wee; Ng, Siew-Cheok; Lim, Einly

    2015-05-01

    A segmental two-parameter empirical deformable model is proposed for evaluating regional motion abnormality of the left ventricle. Short-axis tagged MRI scans were acquired from 10 healthy subjects and 10 postinfarct patients. Two motion parameters, contraction and rotation, were quantified for each cardiac segment by fitting the proposed model using a non-rigid registration algorithm. The accuracy in motion estimation was compared to a global model approach. Motion parameters extracted from patients were correlated to infarct transmurality assessed with delayed-contrast-enhanced MRI. The proposed segmental model allows markedly improved accuracy in regional motion analysis as compared to the global model for both subject groups (1.22-1.40 mm versus 2.31-2.55 mm error). By end-systole, all healthy segments experienced radial displacement by ~25-35% of the epicardial radius, whereas the 3 short-axis planes rotated differently (basal: 3.3° mid:  -1° and apical:  -4.6°) to create a twisting motion. While systolic contraction showed clear correspondence to infarct transmurality, rotation was nonspecific to either infarct location or transmurality but could indicate the presence of functional abnormality. Regional contraction and rotation derived using this model could potentially aid in the assessment of severity of regional dysfunction of infarcted myocardium.

  14. Regional assessment of LV wall in infarcted heart using tagged MRI and cardiac modelling.

    PubMed

    Jahanzad, Zeinab; Liew, Yih Miin; Bilgen, Mehmet; McLaughlin, Robert A; Leong, Chen Onn; Chee, Kok Han; Aziz, Yang Faridah Abdul; Ung, Ngie Min; Lai, Khin Wee; Ng, Siew-Cheok; Lim, Einly

    2015-05-21

    A segmental two-parameter empirical deformable model is proposed for evaluating regional motion abnormality of the left ventricle. Short-axis tagged MRI scans were acquired from 10 healthy subjects and 10 postinfarct patients. Two motion parameters, contraction and rotation, were quantified for each cardiac segment by fitting the proposed model using a non-rigid registration algorithm. The accuracy in motion estimation was compared to a global model approach. Motion parameters extracted from patients were correlated to infarct transmurality assessed with delayed-contrast-enhanced MRI. The proposed segmental model allows markedly improved accuracy in regional motion analysis as compared to the global model for both subject groups (1.22-1.40 mm versus 2.31-2.55 mm error). By end-systole, all healthy segments experienced radial displacement by ~25-35% of the epicardial radius, whereas the 3 short-axis planes rotated differently (basal: 3.3°; mid:  -1° and apical:  -4.6°) to create a twisting motion. While systolic contraction showed clear correspondence to infarct transmurality, rotation was nonspecific to either infarct location or transmurality but could indicate the presence of functional abnormality. Regional contraction and rotation derived using this model could potentially aid in the assessment of severity of regional dysfunction of infarcted myocardium. PMID:25919317

  15. Assessment of cardiac function using myocardial perfusion imaging technique on SPECT with 99mTc sestamibi

    NASA Astrophysics Data System (ADS)

    Gani, M. R. A.; Nazir, F.; Pawiro, S. A.; Soejoko, D. S.

    2016-03-01

    Suspicion on coronary heart disease can be confirmed by observing the function of left ventricle cardiac muscle with Myocardial Perfusion Imaging techniques. The function perfusion itself is indicated by the uptake of radiopharmaceutical tracer. The 31 patients were studied undergoing the MPI examination on Gatot Soebroto Hospital using 99mTc-sestamibi radiopharmaceutical with stress and rest conditions. Stress was stimulated by physical exercise or pharmacological agent. After two hours, the patient did rest condition on the same day. The difference of uptake percentage between stress and rest conditions will be used to determine the malfunction of perfusion due to ischemic or infarct. Degradation of cardiac function was determined based on the image-based assessment of five segments of left ventricle cardiac. As a result, 8 (25.8%) patients had normal myocardial perfusion and 11 (35.5%) patients suspected for having partial ischemia. Total ischemia occurred to 8 (25.8%) patients with reversible and irreversible ischemia and the remaining 4 (12.9%) patients for partial infarct with characteristic the percentage of perfusion ≤50%. It is concluded that MPI technique of image-based assessment on uptake percentage difference between stress and rest conditions can be employed to predict abnormal perfusion as complementary information to diagnose the cardiac function.

  16. Use of biomarkers for the assessment of chemotherapy-induced cardiac toxicity

    PubMed Central

    Christenson, Eric S.; James, Theodore; Agrawal, Vineet; Park, Ben H.

    2015-01-01

    Objectives To review the evidence for the use of various biomarkers in the detection of chemotherapy associated cardiac damage. Design and methods Pubmed.gov was queried using the search words chemotherapy and cardiac biomarkers with the filters of past 10 years, humans, and English language. An emphasis was placed on obtaining primary research articles looking at the utility of biomarkers for the detection of chemotherapy-mediated cardiac injury. Results Biomarkers may help identify patients undergoing treatment who are at high risk for cardiotoxicity and may assist in identification of a low risk cohort that does not necessitate continued intensive screening. cTn assays are the best studied biomarkers in this context and may represent a promising and potentially valuable modality for detecting cardiac toxicity in patients undergoing chemotherapy. Monitoring cTnI levels may provide information regarding the development of cardiac toxicity before left ventricular dysfunction becomes apparent on echocardiography or via clinical symptoms. A host of other biomarkers have been evaluated for their utility in the field of chemotherapy related cardiac toxicity with intermittent success; further trials are necessary to determine what role they may end up playing for prediction and prognostication in this setting. Conclusions Biomarkers represent an exciting potential complement or replacement for echocardiographic monitoring of chemotherapy related cardiac toxicity which may allow for earlier realization of the degree of cardiac damage occurring during treatment, creating the opportunity for more timely modulation of therapy. PMID:25445234

  17. Wearable seismocardiography: towards a beat-by-beat assessment of cardiac mechanics in ambulant subjects.

    PubMed

    Di Rienzo, M; Vaini, E; Castiglioni, P; Merati, G; Meriggi, P; Parati, G; Faini, A; Rizzo, F

    2013-11-01

    Seismocardiogram (SCG) is the measure of the micro-vibrations produced by the heart contraction and blood ejection into the vascular tree. Over time, a large body of evidence has been collected on the ability of SCG to reflect cardiac mechanical events such as opening and closure of mitral and aortic valves, atrial filling and point of maximal aortic blood ejection. We recently developed a smart garment, named MagIC-SCG, that allows the monitoring of SCG, electrocardiogram (ECG) and respiration out of the laboratory setting in ambulant subjects. The present pilot study illustrates the results of two different experiments performed to obtain a first evaluation on whether a dynamical assessment of indexes of cardiac mechanics can be obtained from SCG recordings obtained by MagIC-SCG. In the first experiment, we evaluated the consistency of the estimates of two indexes of cardiac contractility, the pre-ejection period, PEP, and the left ventricular ejection time, LVET. This was done in the lab, by reproducing an experimental protocol well known in literature, so that our measures derived from SCG could have been compared with PEP and LVET reference values obtained by traditional techniques. Six healthy subjects worn MagIC-SCG while assuming two different postures (supine and standing); PEP was estimated as the time interval between the Q wave in ECG and the SCG wave corresponding to the opening of aortic valve; LVET was the time interval between the SCG waves corresponding to the opening and closure of the aortic valve. The shift from supine to standing posture produced a significant increase in PEP and PEP/LVET ratio, a reduction in LVET and a concomitant rise in the LF/HF ratio in the RR interval (RRI) power spectrum. These results are in line with data available in literature thus providing a first support to the validity of our estimates. In the second experiment, we evaluated in one subject the feasibility of the beat-by-beat assessment of LVET during spontaneous behavior. The subject was continuously monitored by the smart garment from 8 am to 8 pm during a workday. From the whole recording, three data segments were selected: while the subject was traveling to work (M1), during work in the office (O) and while traveling back home (M2). LVET was estimated on a beat-by-beat basis from SCG and the RRI influence was removed by regression analysis. The LVET series displayed marked beat-by-beat fluctuations at the respiratory frequency. The amplitude of these fluctuations changed in the three periods and was lower when the LF/HF RRI power ratio was higher, at O, thus suggesting a possible influence of the autonomic nervous system on LVET short-term variability. To the best of our knowledge this case report provides for the first time a representation of the beat-by-beat dynamics of a systolic time interval during daily activity. The statistical characterization of these findings remains to be explored on a larger population. PMID:23664242

  18. Correlation of Prehypertension with Left Ventricular Mass Assessed by Cardiac Magnetic Resonance Imaging

    PubMed Central

    Mousa, Tarek M.; Akinseye, Oluwaseun A.; Berekashvili, Ketevan; Akinboboye, Olakunle O.

    2015-01-01

    Introduction. The purpose of this observational cross-sectional study was to assess left ventricular mass (LVM) in prehypertensive individuals in comparison to normotensives and to determine if central blood pressure (BP) correlates better with LVM index (LVMI) than brachial BP. Methods and Result. Brachial and central BP measurements were completed at first visit and at 4 weeks in 65 healthy volunteers who were at least 40 years old and not on medication. Subjects were divided into two groups of normotensives and prehypertensives based on JNC-7 criteria and LVM was obtained using cardiac magnetic resonance imaging. Prehypertensives had significantly higher LVMI compared to normotensives (P < 0.01). Brachial and central BP also both positively correlate with LVMI (r = 0.460, P < 0.01; r = 0.318, P = 0.012, resp.) in both groups and neither method was superior to the other. After multivariate regression analysis and adjusting for cardiovascular risk factors, prehypertension remained an independent determinant of LVM. Conclusion. Prehypertension is associated with cardiovascular target organ damage, and central BP was not superior to brachial BP or vice versa for association with LVMI. PMID:26543640

  19. Clinical Assessment of Intraventricular Blood Transport in Patients Undergoing Cardiac Resynchronization Therapy

    NASA Astrophysics Data System (ADS)

    Rossini, Lorenzo; Martinez-Legazpi, P.; Benito, Y.; Perez Del Villar, C.; Gonzalez-Mansilla, A.; Barrio, A.; Yotti, R.; Kahn, A. M.; Shadden, S. C.; Fernandez-Aviles, F.; Bermejo, J.; Del Alamo, J. C.

    2015-11-01

    In the healthy heart, left ventricular (LV) filling generates flow patterns which have been proposed to optimize blood transport by coupling diastole and systole phases. We present a novel image-based method to assess how flow patterns influence LV blood transport in patients undergoing cardiac resynchronization therapy (CRT). Solving the advection equation with time-varying inflow boundary conditions allows to track the transport of blood entering the LV in the different filling waves, as well as the transport barriers which couple filling and ejection. The velocity fields were obtained using echocardiographic color Doppler velocimetry, which provides two-dimensional time-resolved flow maps in the apical long axis three-chamber view of the LV. We analyze flow transport in a group of patients with CRT devices as well as in healthy volunteers. In the patients under CRT, the device programming was varied to analyze flow transport under different values of the atrioventricular (AV) conduction delay and to model tachycardia. This analysis illustrates how CRT influences the transit of blood inside the LV, contributes to conserving kinetic energy and favors the generation of hemodynamic forces that accelerate blood in the direction of the LV outflow tract.

  20. Assessment of potential drug-drug interactions and its associated factors in the hospitalized cardiac patients.

    PubMed

    Murtaza, Ghulam; Khan, Muhammad Yasir Ghani; Azhar, Saira; Khan, Shujaat Ali; Khan, Tahir M

    2016-03-01

    Drug-drug interactions (DDIs) may result in the alteration of therapeutic response. Sometimes they may increase the untoward effects of many drugs. Hospitalized cardiac patients need more attention regarding drug-drug interactions due to complexity of their disease and therapeutic regimen. This research was performed to find out types, prevalence and association between various predictors of potential drug-drug interactions (pDDIs) in the Department of Cardiology and to report common interactions. This study was performed in the hospitalized cardiac patients at Ayub Teaching Hospital, Abbottabad, Pakistan. Patient charts of 2342 patients were assessed for pDDIs using Micromedex® Drug Information. Logistic regression was applied to find predictors of pDDIs. The main outcome measure in the study was the association of the potential drug-drug interactions with various factors such as age, gender, polypharmacy, and hospital stay of the patients. We identified 53 interacting-combinations that were present in total 5109 pDDIs with median number of 02 pDDIs per patient. Overall, 91.6% patients had at least one pDDI; 86.3% were having at least one major pDDI, and 84.5% patients had at least one moderate pDDI. Among 5109 identified pDDIs, most were of moderate (55%) or major severity (45%); established (24.2%), theoretical (18.8%) or probable (57%) type of scientific evidence. Top 10 common pDDIs included 3 major and 7 moderate interactions. Results obtained by multivariate logistic regression revealed a significant association of the occurrence of pDDIs in patient with age of 60 years or more (p < 0.001), hospital stay of 7 days or longer (p < 0.001) and taking 7 or more drugs (p < 0.001). We found a high prevalence for pDDIs in the Department of Cardiology, most of which were of moderate severity. Older patients, patients with longer hospital stay and with elevated number of prescribed drugs were at higher risk of pDDIs. PMID:27013915

  1. Assessment of potential drug–drug interactions and its associated factors in the hospitalized cardiac patients

    PubMed Central

    Murtaza, Ghulam; Khan, Muhammad Yasir Ghani; Azhar, Saira; Khan, Shujaat Ali; Khan, Tahir M.

    2015-01-01

    Drug–drug interactions (DDIs) may result in the alteration of therapeutic response. Sometimes they may increase the untoward effects of many drugs. Hospitalized cardiac patients need more attention regarding drug–drug interactions due to complexity of their disease and therapeutic regimen. This research was performed to find out types, prevalence and association between various predictors of potential drug–drug interactions (pDDIs) in the Department of Cardiology and to report common interactions. This study was performed in the hospitalized cardiac patients at Ayub Teaching Hospital, Abbottabad, Pakistan. Patient charts of 2342 patients were assessed for pDDIs using Micromedex® Drug Information. Logistic regression was applied to find predictors of pDDIs. The main outcome measure in the study was the association of the potential drug–drug interactions with various factors such as age, gender, polypharmacy, and hospital stay of the patients. We identified 53 interacting-combinations that were present in total 5109 pDDIs with median number of 02 pDDIs per patient. Overall, 91.6% patients had at least one pDDI; 86.3% were having at least one major pDDI, and 84.5% patients had at least one moderate pDDI. Among 5109 identified pDDIs, most were of moderate (55%) or major severity (45%); established (24.2%), theoretical (18.8%) or probable (57%) type of scientific evidence. Top 10 common pDDIs included 3 major and 7 moderate interactions. Results obtained by multivariate logistic regression revealed a significant association of the occurrence of pDDIs in patient with age of 60 years or more (p < 0.001), hospital stay of 7 days or longer (p < 0.001) and taking 7 or more drugs (p < 0.001). We found a high prevalence for pDDIs in the Department of Cardiology, most of which were of moderate severity. Older patients, patients with longer hospital stay and with elevated number of prescribed drugs were at higher risk of pDDIs. PMID:27013915

  2. Detecting drug-induced prolongation of the QRS complex: New insights for cardiac safety assessment

    SciTech Connect

    Cros, C.; Skinner, M.; Moors, J.; Lainee, P.; Valentin, J.P.

    2012-12-01

    Background: Drugs slowing the conduction of the cardiac action potential and prolonging QRS complex duration by blocking the sodium current (I{sub Na}) may carry pro-arrhythmic risks. Due to the frequency-dependent block of I{sub Na}, this study assesses whether activity-related spontaneous increases in heart rate (HR) occurring during standard dog telemetry studies can be used to optimise the detection of class I antiarrhythmic-induced QRS prolongation. Methods: Telemetered dogs were orally dosed with quinidine (class Ia), mexiletine (class Ib) or flecainide (class Ic). QRS duration was determined standardly (5 beats averaged at rest) but also prior to and at the plateau of each acute increase in HR (3 beats averaged at steady state), and averaged over 1 h period from 1 h pre-dose to 5 h post-dose. Results: Compared to time-matched vehicle, at rest, only quinidine and flecainide induced increases in QRS duration (E{sub max} 13% and 20% respectively, P < 0.01–0.001) whereas mexiletine had no effect. Importantly, the increase in QRS duration was enhanced at peak HR with an additional effect of + 0.7 ± 0.5 ms (quinidine, NS), + 1.8 ± 0.8 ms (mexiletine, P < 0.05) and + 2.8 ± 0.8 ms (flecainide, P < 0.01) (calculated as QRS at basal HR-QRS at high HR). Conclusion: Electrocardiogram recordings during elevated HR, not considered during routine analysis optimised for detecting QT prolongation, can be used to sensitise the detection of QRS prolongation. This could prove useful when borderline QRS effects are detected. Analysing during acute increases in HR could also be useful for detecting drug-induced effects on other aspects of cardiac function. -- Highlights: ► We aimed to improve detection of drug-induced QRS prolongation in safety screening. ► We used telemetered dogs to test class I antiarrhythmics at low and high heart rate. ► At low heart rate only quinidine and flecainide induced an increase in QRS duration. ► At high heart rate the effects of two out of three antiarrhythmics were enhanced. ► Detection of a drug-induced prolongation of QRS was improved at high heart rate.

  3. Assessment of cardiac function during mechanical circulatory support: the quest for a suitable clinical index.

    PubMed

    Ferreira, Antonio L; Wang, Yajuan; Gorcsan, John; Antaki, James F

    2011-01-01

    A new index to assess left ventricular (LV) function in patients implanted with continuous flow left-ventricular assist devices (LVADs) is proposed. Derived from the pump flow signal, this index is defined as the coefficient (k) of the semilogarithmic relationship between "pseudo-ejection" fraction (pEF) and the volume discharged by the pump in diastole, (V d). pEF is defined as the ratio of the "pseudo-stroke volume" (pSV) to V d. The pseudo-stroke volume is the difference between V d and the volume discharged by the pump in systole (V s), both obtained by integrating pump flow with respect to time in a cardiac cycle. k was compared in-vivo with others two indices: the LV pressure-based index, M(TP), and the pump flow-based index, I(Q). M(TP) is the slope of the linear regression between the "triple-product" and end-diastolic pressure, EDP. The triple-product, TP = LV SP.dP/dt(max). HR, is the product of LV systolic pressure, maximum time-derivative of LV pressure, and heart rate. I(Q) is the slope of the linear regression between maximum time-derivative of pump flow, dQ/dt(max), and pump flow peak-to-peak amplitude variation, Q(P2P). To test the response of k to contractile state changes, contractility was altered through pharmacological interventions. The absolute value of k decreased from 1.354 ± 0.25 (baseline) to 0.685 ± 0.21 after esmolol infusion. The proposed index is sensitive to changes in inotropic state, and has the potential to be used clinically to assess contractile function of patients implanted with VAD. PMID:22254290

  4. Cardiac biomarkers in cats.

    PubMed

    Borgeat, K; Connolly, D J; Luis Fuentes, V

    2015-12-01

    Cardiac biomarkers have been used in cats as part of the clinical assessment of heart disease for over a decade. They are widely available to practitioners through commercial reference laboratories. The evidence base for the use of cardiac biomarkers (primarily N-terminal pro-B type natriuretic peptide and cardiac troponin I) in cats is comprehensively reviewed in this article, focusing on each of six specific areas: distinguishing cardiac from non-cardiac causes of respiratory distress; measurement of cardiac biomarkers in urine and pleural fluid; identification of occult cardiomyopathy; effects of systemic disease on circulating concentrations of cardiac biomarkers; point-of-care biomarker testing, and the possible prognostic utility of cardiac biomarker measurement. PMID:26776596

  5. Cost and effectiveness assessment of cardiac rehabilitation for dialysis patients following coronary bypass

    PubMed Central

    Huang, Yijian; Zhang, Rebecca; Culler, Steven; Kutner, Nancy

    2009-01-01

    Dialysis patients have a high risk of cardiovascular disease. In the general population, cardiac rehabilitation is recommended as a standard component of care and is covered by Medicare for patients who have undergone coronary artery bypass grafting (CABG). Previous investigation demonstrated survival benefit of cardiac rehabilitation in dialysis patients. This study investigated its impact on Medicare expenditure and its cost effectiveness. A cohort of 4,324 end-stage renal disease (ESRD) patients who initiated chronic hemodialysis and underwent CABG between 1998 and 2004 was selected from the United States Renal Data System. Cardiac rehabilitation was defined by Current Procedural Terminology codes for monitored and nonmonitored exercise in Medicare claims data. Medicare expenditure included inpatient and outpatient claims with cost adjusted to 1998 dollars. At 42 months of follow-up after a 6-month entry period following CABG hospitalization discharge, cardiac rehabilitation at baseline was associated with higher cumulative Medicare expenditure, incurring a statistically nonsignificant increment of $2,904 (95% CI: −7,028, 11,940). During the same period, cardiac rehabilitation was significantly associated with longer cumulative lifetime, having an incremental benefit of 76 days (95% CI: 22, 129). The incremental cost-effectiveness ratio was $13,887 per year of life saved, suggesting that cardiac rehabilitation is highly cost-effective in ESRD patients following CABG. PMID:18650790

  6. Comprehensible Output?

    ERIC Educational Resources Information Center

    Krashen, Stephen

    1998-01-01

    Discusses the comprehensible output (CO) hypothesis, which states that we acquire language when we attempt to transmit a message to a conversation partner, fail, try again, and eventually arrive at the correct form of the utterance. Examines weaknesses of the CO hypothesis in second language acquisition, suggesting that providing more…

  7. Preoperative levosimendan decreases mortality and the development of low cardiac output in high-risk patients with severe left ventricular dysfunction undergoing coronary artery bypass grafting with cardiopulmonary bypass

    PubMed Central

    Levin, Ricardo; Degrange, Marcela; Del Mazo, Carlos; Tanus, Eduardo; Porcile, Rafael

    2012-01-01

    BACKGROUND: The calcium sensitizer levosimendan has been used in cardiac surgery for the treatment of postoperative low cardiac output syndrome (LCOS) and difficult weaning from cardiopulmonary bypass (CPB). OBJECTIVES: To evaluate the effects of preoperative treatment with levosimendan on 30-day mortality, the risk of developing LCOS and the requirement for inotropes, vasopressors and intra-aortic balloon pumps in patients with severe left ventricular dysfunction. METHODS: Patient with severe left ventricular dysfunction and an ejection fraction <25% undergoing coronary artery bypass grafting with CPB were admitted 24 h before surgery and were randomly assigned to receive levosimendan (loading dose 10 μg/kg followed by a 23 h continuous infusion of 0.1μg/kg/min) or a placebo. RESULTS: From December 1, 2002 to June 1, 2008, a total of 252 patients were enrolled (127 in the levosimendan group and 125 in the control group). Individuals treated with levosimendan exhibited a lower incidence of complicated weaning from CPB (2.4% versus 9.6%; P<0.05), decreased mortality (3.9% versus 12.8%; P<0.05) and a lower incidence of LCOS (7.1% versus 20.8%; P<0.05) compared with the control group. The levosimendan group also had a lower requirement for inotropes (7.9% versus 58.4%; P<0.05), vasopressors (14.2% versus 45.6%; P<0.05) and intra-aortic balloon pumps (6.3% versus 30.4%; P<0.05). CONCLUSION: Patients with severe left ventricle dysfunction (ejection fraction <25%) undergoing coronary artery bypass grafting with CPB who were pretreated with levosimendan exhibited lower mortality, a decreased risk for developing LCOS and a reduced requirement for inotropes, vasopressors and intra-aortic balloon pumps. Studies with a larger number of patients are required to confirm whether these findings represent a new strategy to reduce the operative risk in this high-risk patient population. PMID:23620700

  8. Cardiac Rehabilitation

    MedlinePlus

    ... from the NHLBI on Twitter. What Is Cardiac Rehabilitation? Cardiac rehabilitation (rehab) is a medically supervised program ... be designed to meet your needs. The Cardiac Rehabilitation Team Cardiac rehab involves a long-term commitment ...

  9. Early cardiology assessment and intervention reduces mortality following myocardial injury after non-cardiac surgery (MINS)

    PubMed Central

    Hua, Alina; Pattenden, Holly; Leung, Maria; Davies, Simon; George, David A.; Raubenheimer, Hilgardt; Niwaz, Zakiyah

    2016-01-01

    Background Myocardial injury after non-cardiac surgery (MINS) is defined as troponin elevation of ≥0.03 ng/mL associated with 3.87-fold increase in early mortality. We sought to determine the impact of cardiology intervention on mortality in patients who developed MINS after general thoracic surgery. Methods A retrospective review was performed in patients over 5 years. Troponin was routinely measured and levels ≥0.04 ng/mL classified as positive. Data acquisition and mortality status was obtained via medical records and NHS tracing systems. Thirty-day mortality was compared on MINS cohort using Fisher’s exact square testing and logistic regression analysis. Results Troponin levels were measured in 491 (96%) of 511 patients. Eighty (16%) patients fulfilled the MINS criteria. Sixty-one (76%) received early cardiology consult and “myocardial infarction” stated in four (5%) patients. Risk assessment (for AMI) was undertaken; 20 (25%) patients were commenced on aspirin, four (5%) on β-blockers and one (1%) underwent percutaneous coronary intervention. Forty-nine (61%) patients received primary risk factor modifications and 26 (33%) had outpatient follow-up. There were no significant differences in the proportion of patients who died within 30 days post-operatively in the MINS group of 2.6% compared to the non-MINS group of 1.6% (P=0.625). The odds ratio for 30-day mortality in the MINS group was 1.69 (95% CI: 0.34 to 8.57, P=0.522). Conclusions MINS is common after general thoracic surgery. Early cardiology intervention reduced the expected hazard ratio of early death from 3.87 to an odds ratio of 1.69 with no significant difference in 30-day mortality for patients who developed MINS. PMID:27162667

  10. A Novel Quantitative Method for Diabetic Cardiac Autonomic Neuropathy Assessment in Type 1 Diabetic Mice

    PubMed Central

    Yang, Bufan; Posada-Quintero, Hugo F.; Siu, Kin L.; Rolle, Marsha; Brink, Peter; Birzgalis, Aija; Moore, Leon C.

    2014-01-01

    In this work, we used a sensitive and noninvasive computational method to assess diabetic cardiovascular autonomic neuropathy (DCAN) from pulse oximeter (photoplethysmographic; PPG) recordings from mice. The method, which could be easily applied to humans, is based on principal dynamic mode (PDM) analysis of heart rate variability (HRV). Unlike the power spectral density, PDM has been shown to be able to separately identify the activities of the parasympathetic and sympathetic nervous systems without pharmacological intervention. HRV parameters were measured by processing PPG signals from conscious 1.5- to 5-month-old C57/BL6 control mice and in Akita mice, a model of insulin-dependent type 1 diabetes, and compared with the gold-standard Western blot and immunohistochemical analyses. The PDM results indicate significant cardiac autonomic impairment in the diabetic mice in comparison to the controls. When tail-cuff PPG recordings were collected and analyzed starting from 1.5 months of age in both C57/Bl6 controls and Akita mice, onset of DCAN was seen at 3 months in the Akita mice, which persisted up to the termination of the recording at 5 months. Western blot and immunohistochemical analyses also showed a reduction in nerve density in Akita mice at 3 and 4 months as compared to the control mice, thus, corroborating our PDM data analysis of HRV records. Western blot analysis of autonomic nerve proteins corroborated the PPG-based HRV analysis via the PDM approach. In contrast, traditional HRV analysis (based on either the power spectral density or time-domain measures) failed to detect the nerve rarefaction. PMID:25097056

  11. A novel quantitative method for diabetic cardiac autonomic neuropathy assessment in type 1 diabetic mice.

    PubMed

    Chon, Ki H; Yang, Bufan; Posada-Quintero, Hugo F; Siu, Kin L; Rolle, Marsha; Brink, Peter; Birzgalis, Aija; Moore, Leon C

    2014-11-01

    In this work, we used a sensitive and noninvasive computational method to assess diabetic cardiovascular autonomic neuropathy (DCAN) from pulse oximeter (photoplethysmographic; PPG) recordings from mice. The method, which could be easily applied to humans, is based on principal dynamic mode (PDM) analysis of heart rate variability (HRV). Unlike the power spectral density, PDM has been shown to be able to separately identify the activities of the parasympathetic and sympathetic nervous systems without pharmacological intervention. HRV parameters were measured by processing PPG signals from conscious 1.5- to 5-month-old C57/BL6 control mice and in Akita mice, a model of insulin-dependent type 1 diabetes, and compared with the gold-standard Western blot and immunohistochemical analyses. The PDM results indicate significant cardiac autonomic impairment in the diabetic mice in comparison to the controls. When tail-cuff PPG recordings were collected and analyzed starting from 1.5 months of age in both C57/Bl6 controls and Akita mice, onset of DCAN was seen at 3 months in the Akita mice, which persisted up to the termination of the recording at 5 months. Western blot and immunohistochemical analyses also showed a reduction in nerve density in Akita mice at 3 and 4 months as compared to the control mice, thus, corroborating our PDM data analysis of HRV records. Western blot analysis of autonomic nerve proteins corroborated the PPG-based HRV analysis via the PDM approach. In contrast, traditional HRV analysis (based on either the power spectral density or time-domain measures) failed to detect the nerve rarefaction. PMID:25097056

  12. A time-saving method to assess power output at lactate threshold in well-trained and elite cyclists.

    PubMed

    Støren, Øyvind; Rønnestad, Bent R; Sunde, Arnstein; Hansen, Joar; Ellefsen, Stian; Helgerud, Jan

    2014-03-01

    The purpose of this study was to examine the relationship between lactate threshold (LT) as a percentage of maximal oxygen consumption (V[Combining Dot Above]O2max) and power output at LT (LTW) and also to investigate to what extent V[Combining Dot Above]O2max, oxygen cost of cycling (CC), and maximal aerobic power (MAP) determine LTW in cycling to develop a new time-saving model for testing LTW. To do this, 108 male competitive cyclists with an average V[Combining Dot Above]O2max of 65.2 ± 7.4 ml·kg·min and an average LTW of 274 ± 43 W were tested for V[Combining Dot Above]O2max, LT %V[Combining Dot Above]O2max, LTW, MAP, and CC on a test ergometer cycle. The product of MAP and individual LT in %V[Combining Dot Above]O2max was found to be a good determinant of LTW (R = 0.98, p < 0.0001). However, LT in %V[Combining Dot Above]O2max was found to be a poor determinant of LTW (R = 0.39, p < 0.0001). Based on these findings, we have suggested a new time-saving method for calculating LTW in well-trained cyclists. The benefits from this model come both from tracking LTW during training interventions and from regularly assessing training status in competitive cyclists. Briefly, this method is based on the present findings that LTW depends on LT in %V[Combining Dot Above]O2max, V[Combining Dot Above]O2max, and CC and may after an initial test session reduce the time for the subsequent testing of LTW by as much as 50% without the need for blood samples. PMID:23942166

  13. A mixed-unit input-output model for environmental life-cycle assessment and material flow analysis.

    PubMed

    Hawkins, Troy; Hendrickson, Chris; Higgins, Cortney; Matthews, H Scott; Suh, Sangwon

    2007-02-01

    Materials flow analysis models have traditionally been used to track the production, use, and consumption of materials. Economic input-output modeling has been used for environmental systems analysis, with a primary benefit being the capability to estimate direct and indirect economic and environmental impacts across the entire supply chain of production in an economy. We combine these two types of models to create a mixed-unit input-output model that is able to bettertrack economic transactions and material flows throughout the economy associated with changes in production. A 13 by 13 economic input-output direct requirements matrix developed by the U.S. Bureau of Economic Analysis is augmented with material flow data derived from those published by the U.S. Geological Survey in the formulation of illustrative mixed-unit input-output models for lead and cadmium. The resulting model provides the capabilities of both material flow and input-output models, with detailed material tracking through entire supply chains in response to any monetary or material demand. Examples of these models are provided along with a discussion of uncertainty and extensions to these models. PMID:17328219

  14. Intensity-level assessment of lower body plyometric exercises based on mechanical output of lower limb joints.

    PubMed

    Sugisaki, Norihide; Okada, Junichi; Kanehisa, Hiroaki

    2013-01-01

    The present study aimed to quantify the intensity of lower extremity plyometric exercises by determining joint mechanical output. Ten men (age, 27.3 ± 4.1 years; height, 173.6 ± 5.4 cm; weight, 69.4 ± 6.0 kg; 1-repetition maximum [1RM] load in back squat 118.5 ± 12.0 kg) performed the following seven plyometric exercises: two-foot ankle hop, repeated squat jump, double-leg hop, depth jumps from 30 and 60 cm, and single-leg and double-leg tuck jumps. Mechanical output variables (torque, angular impulse, power, and work) at the lower limb joints were determined using inverse-dynamics analysis. For all measured variables, ANOVA revealed significant main effects of exercise type for all joints (P < 0.05) along with significant interactions between joint and exercise (P < 0.01), indicating that the influence of exercise type on mechanical output varied among joints. Paired comparisons revealed that there were marked differences in mechanical output at the ankle and hip joints; most of the variables at the ankle joint were greatest for two-foot ankle hop and tuck jumps, while most hip joint variables were greatest for repeated squat jump or double-leg hop. The present results indicate the necessity for determining mechanical output for each joint when evaluating the intensity of plyometric exercises. PMID:23327555

  15. Quantitative Assessment of Left Ventricular Function and Myocardial Mass: A Comparison of Coronary CT Angiography with Cardiac MRI and Echocardiography

    PubMed Central

    Kara, Bedia; Nayman, Alaaddin; Guler, Ibrahim; Gul, Enes Elvin; Koplay, Mustafa; Paksoy, Yahya

    2016-01-01

    Summary Background The purpose of this study was to compare the left ventricular parameters obtained from multi-detector row computed tomography (MDCT) studies with two-dimensional echocardiography (2DE), and magnetic resonance imaging (MRI), which is accepted as the gold standard in the evaluation of left ventricular functions. The study also aimed to evaluate whether or not there is a relationship between the MR-Argus and CMR tools software programs which are used in post-process calculations of data obtained by MRI. Material/Methods Forty patients with an average age of 51.4±14.9 years who had been scanned with cardiac MDCT were evaluated with cardiac MRI and 2DE. End-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV), ejection fraction (EF), cardiac output (CO), and myocardial mass values calculated by MDCT, MRI, and 2DE were compared with each other. Two different MR software programs were used to compare left ventricular functions. The CMR tools LV tutorials method is accepted as the gold standard because it can be used in three-dimensional functional evaluation. The Pearson Correlation and Bland-Altman analysis were performed to compare the results from the two MR methods (MR-Argus and CMR tools) and the results from both the MDCT and the 2DE with the CMR tools results. Results Strong positive correlations for EF values were found between the MDCT and CMR tools (r=0.702 p<0.001), and between the MR-Argus and CMR tools (r=0.746 p<0.001). The correlation between the 2DE and CMR tools (r=0.449 p<0.004), however, was only moderate. Similar results were obtained for the other parameters. The strongest correlation for ESV, EDV, and EF was between the two MR software programs. The correlation coefficient between the MDCT and CMR tools is close to the correlation coefficient between the two software programs. While the correlation between 2DE and CMR tools was satisfactory for ESV, EDV, and CO values, it was at a moderate level for the other parameters. Conclusions Left ventricular functional analysis can be performed easily and reliably with cardiac MDCT used for coronary artery evaluation and it also gives more accurate results than 2DE. PMID:27026794

  16. A microchip-based multianalyte assay system for the assessment of cardiac risk.

    PubMed

    Christodoulides, Nick; Tran, Maiyen; Floriano, Pierre N; Rodriguez, Marc; Goodey, Adrian; Ali, Mehnaaz; Neikirk, Dean; McDevitt, John T

    2002-07-01

    The development of a novel chip-based multianalyte detection system with a cardiac theme is reported. This work follows the initial reports of "electronic taste chips" whereby multiple solution-phase analytes such as acids, bases, metal cations, and biological cofactors were detected and quantitated. The newly fashioned "cardiac chip" exploits a geometry that allows for isolation and entrapment of single polymeric spheres in micromachined pits while providing to each bead the rapid introduction of a series of reagents/washes through microfluidic structures. The combination of these miniaturized components fosters the completion of complex assays with short analysis times using small sample volumes. Optical signals derived from single beads are used to complete immunological tests that yield outstanding assay characteristics. The power and utility of this new methodology is demonstrated here for the simultaneous detection of the cardiac risk factors, C-reactive protein and interleukin-6, in human serum samples. This demonstration represents the first important step toward the development of a useful cardiac chip that targets numerous risk factors concurrently and one that can be customized readily for specific clinical settings. PMID:12141661

  17. Sympathetic restraint of respiratory sinus arrhythmia: implications for vagal-cardiac tone assessment in humans

    NASA Technical Reports Server (NTRS)

    Taylor, J. A.; Myers, C. W.; Halliwill, J. R.; Seidel, H.; Eckberg, D. L.

    2001-01-01

    Clinicians and experimentalists routinely estimate vagal-cardiac nerve traffic from respiratory sinus arrhythmia. However, evidence suggests that sympathetic mechanisms may also modulate respiratory sinus arrhythmia. Our study examined modulation of respiratory sinus arrhythmia by sympathetic outflow. We measured R-R interval spectral power in 10 volunteers that breathed sequentially at 13 frequencies, from 15 to 3 breaths/min, before and after beta-adrenergic blockade. We fitted changes of respiratory frequency R-R interval spectral power with a damped oscillator model: frequency-dependent oscillations with a resonant frequency, generated by driving forces and modified by damping influences. beta-Adrenergic blockade enhanced respiratory sinus arrhythmia at all frequencies (at some, fourfold). The damped oscillator model fit experimental data well (39 of 40 ramps; r = 0.86 +/- 0.02). beta-Adrenergic blockade increased respiratory sinus arrhythmia by amplifying respiration-related driving forces (P < 0.05), without altering resonant frequency or damping influences. Both spectral power data and the damped oscillator model indicate that cardiac sympathetic outflow markedly reduces heart period oscillations at all frequencies. This challenges the notion that respiratory sinus arrhythmia is mediated simply by vagal-cardiac nerve activity. These results have important implications for clinical and experimental estimation of human vagal cardiac tone.

  18. Optogenetics-enabled assessment of viral gene and cell therapy for restoration of cardiac excitability.

    PubMed

    Ambrosi, Christina M; Boyle, Patrick M; Chen, Kay; Trayanova, Natalia A; Entcheva, Emilia

    2015-01-01

    Multiple cardiac pathologies are accompanied by loss of tissue excitability, which leads to a range of heart rhythm disorders (arrhythmias). In addition to electronic device therapy (i.e. implantable pacemakers and cardioverter/defibrillators), biological approaches have recently been explored to restore pacemaking ability and to correct conduction slowing in the heart by delivering excitatory ion channels or ion channel agonists. Using optogenetics as a tool to selectively interrogate only cells transduced to produce an exogenous excitatory ion current, we experimentally and computationally quantify the efficiency of such biological approaches in rescuing cardiac excitability as a function of the mode of application (viral gene delivery or cell delivery) and the geometry of the transduced region (focal or spatially-distributed). We demonstrate that for each configuration (delivery mode and spatial pattern), the optical energy needed to excite can be used to predict therapeutic efficiency of excitability restoration. Taken directly, these results can help guide optogenetic interventions for light-based control of cardiac excitation. More generally, our findings can help optimize gene therapy for restoration of cardiac excitability. PMID:26621212

  19. Optogenetics-enabled assessment of viral gene and cell therapy for restoration of cardiac excitability

    PubMed Central

    Ambrosi, Christina M.; Boyle, Patrick M.; Chen, Kay; Trayanova, Natalia A.; Entcheva, Emilia

    2015-01-01

    Multiple cardiac pathologies are accompanied by loss of tissue excitability, which leads to a range of heart rhythm disorders (arrhythmias). In addition to electronic device therapy (i.e. implantable pacemakers and cardioverter/defibrillators), biological approaches have recently been explored to restore pacemaking ability and to correct conduction slowing in the heart by delivering excitatory ion channels or ion channel agonists. Using optogenetics as a tool to selectively interrogate only cells transduced to produce an exogenous excitatory ion current, we experimentally and computationally quantify the efficiency of such biological approaches in rescuing cardiac excitability as a function of the mode of application (viral gene delivery or cell delivery) and the geometry of the transduced region (focal or spatially-distributed). We demonstrate that for each configuration (delivery mode and spatial pattern), the optical energy needed to excite can be used to predict therapeutic efficiency of excitability restoration. Taken directly, these results can help guide optogenetic interventions for light-based control of cardiac excitation. More generally, our findings can help optimize gene therapy for restoration of cardiac excitability. PMID:26621212

  20. MIBG scintigraphic assessment of cardiac adrenergic activity in response to altitude hypoxia

    SciTech Connect

    Richalet, J.P.; Merlet, P.; Bourguignon, M.; Le-Trong, J.L.; Keromes, A.; Rathat, C.; Jouve, B.; Hot, M.A.; Castaigne, A.; Syrota, A. )

    1990-01-01

    High altitude hypoxia induces a decrease in the cardiac chronotropic function at maximal exercise or in response to isoproterenol infusion, suggesting an alteration in the cardiac sympathetic activation. Iodine-123 metaiodobenzylguanidine (({sup 123}I)MIBG) was used to map scintigraphically the cardiac sympathetic neuronal function in six male subjects (aged 32 {plus minus} 7 yr) after an exposure to high altitude that created hypoxic conditions. Results obtained just after return to sea level (RSL) were compared with the normal values obtained after 2 or 3 mo of normoxia (N). A static image was created as the sum of the 16-EKG gated images recorded for 10 min in the anterior view of the chest at 20, 60, 120, and 240 min after injection. Regions of interest were located over the heart (H), lungs (L), and mediastinum (M) regions. There was a significant decrease in the H/M and the L/M ratios in RSL compared to N condition. Plasma norepinephrine concentration was elevated during the stay at altitude but not significantly different in RSL compared to N. In conclusion, cardiac ({sup 123}I)MIBG uptake is reduced after an exposure to altitude hypoxia, supporting the hypothesis of an hypoxia-induced reduction of adrenergic neurotransmitter reserve in the myocardium. Furthermore, the observed significant decrease in pulmonary MIBG uptake suggests an alteration of endothelial cell function after exposure to chronic hypoxia.

  1. Assessment of Myocardial Infarction by Cardiac Magnetic Resonance Imaging and Long-Term Mortality

    PubMed Central

    Petriz, João Luiz Fernandes; Gomes, Bruno Ferraz de Oliveira; Rua, Braulio Santos; Azevedo, Clério Francisco; Hadlich, Marcelo Souza; Mussi, Henrique Thadeu Periard; Taets, Gunnar de Cunto; do Nascimento, Emília Matos; Pereira, Basílio de Bragança; e Silva, Nelson Albuquerque de Souza

    2015-01-01

    Background Cardiac magnetic resonance imaging provides detailed anatomical information on infarction. However, few studies have investigated the association of these data with mortality after acute myocardial infarction. Objective To study the association between data regarding infarct size and anatomy, as obtained from cardiac magnetic resonance imaging after acute myocardial infarction, and long-term mortality. Methods A total of 1959 reports of “infarct size” were identified in 7119 cardiac magnetic resonance imaging studies, of which 420 had clinical and laboratory confirmation of previous myocardial infarction. The variables studied were the classic risk factors – left ventricular ejection fraction, categorized ventricular function, and location of acute myocardial infarction. Infarct size and acute myocardial infarction extent and transmurality were analyzed alone and together, using the variable named “MET-AMI”. The statistical analysis was carried out using the elastic net regularization, with the Cox model and survival trees. Results The mean age was 62.3 ± 12 years, and 77.3% were males. During the mean follow-up of 6.4 ± 2.9 years, there were 76 deaths (18.1%). Serum creatinine, diabetes mellitus and previous myocardial infarction were independently associated with mortality. Age was the main explanatory factor. The cardiac magnetic resonance imaging variables independently associated with mortality were transmurality of acute myocardial infarction (p = 0.047), ventricular dysfunction (p = 0.0005) and infarcted size (p = 0.0005); the latter was the main explanatory variable for ischemic heart disease death. The MET-AMI variable was the most strongly associated with risk of ischemic heart disease death (HR: 16.04; 95%CI: 2.64-97.5; p = 0.003). Conclusion The anatomical data of infarction, obtained from cardiac magnetic resonance imaging after acute myocardial infarction, were independently associated with long-term mortality, especially for ischemic heart disease death. PMID:25424161

  2. Stress cardiac MR imaging: the role of stress functional assessment and perfusion imaging in the evaluation of ischemic heart disease.

    PubMed

    Al Sayari, Saeed; Kopp, Sebastien; Bremerich, Jens

    2015-03-01

    Stress cardiac magnetic resonance imaging can provide valuable information for the diagnosis and management of ischemic heart disease (IHD). It plays an important role in the initial diagnosis in patients with acute chest pain, in the diagnosis of complications post myocardial infarction (MI), in the assessment of the right ventricle after an acute MI, to detect complications due to or after interventions, in prediction of myocardial recovery, to detect inducible ischemia in patients with known IHD, in differentiating ischemic from non-ischemic dilated cardiomyopathy, and in risk stratification. PMID:25727000

  3. Towards an atrio-ventricular delay optimization assessed by a computer model for cardiac resynchronization therapy

    NASA Astrophysics Data System (ADS)

    Ojeda, David; Le Rolle, Virginie; Tse Ve Koon, Kevin; Thebault, Christophe; Donal, Erwan; Hernández, Alfredo I.

    2013-11-01

    In this paper, lumped-parameter models of the cardiovascular system, the cardiac electrical conduction system and a pacemaker are coupled to generate mitral ow pro les for di erent atrio-ventricular delay (AVD) con gurations, in the context of cardiac resynchronization therapy (CRT). First, we perform a local sensitivity analysis of left ventricular and left atrial parameters on mitral ow characteristics, namely E and A wave amplitude, mitral ow duration, and mitral ow time integral. Additionally, a global sensitivity analysis over all model parameters is presented to screen for the most relevant parameters that a ect the same mitral ow characteristics. Results provide insight on the in uence of left ventricle and atrium in uence on mitral ow pro les. This information will be useful for future parameter estimation of the model that could reproduce the mitral ow pro les and cardiovascular hemodynamics of patients undergoing AVD optimization during CRT.

  4. Assessing quality in cardiac surgery: why this is necessary in the twenty-first century

    NASA Technical Reports Server (NTRS)

    Swain, J. A.; Hartz, R. S.

    2000-01-01

    The cost and high-profile nature of coronary surgery means that this is an area of close public scrutiny. As much pioneering work in data collection and risk analyses has been carried out by cardiac surgeons, substantial information exists and the correct interpretation of that data is identified as an important issue. This paper considers the background and history of risk-adjustment in cardiac surgery, the uses of quality data, examines the observed/expected mortality ratio and looks at issues such as cost and reactions to outliers. The conclusion of the study is that the continuation of accurate data collection by the whole operative team and a strong commitment to constantly improving quality is crucial to its meaningful application.

  5. Novel Biomarkers for Cardiac Surgery-Associated Acute Kidney Injury: A Skeptical Assessment of Their Role

    PubMed Central

    Sidebotham, David

    2012-01-01

    Abstract: Cardiac surgery-associated acute kidney injury (AKI) is common and is associated with a high mortality rate. Traditional biomarkers of AKI (creatinine and urea) increase slowly in response to renal injury, are insensitive to mild degrees of AKI, and are influenced by nonrenal factors. There is considerable interest in novel biomarkers of AKI such as neutrophil gelatinase-associated lipocalin that increase rapidly after renal injury, detect mild degrees of AKI, and are less subject to nonrenal factors. It has been postulated that the early diagnosis of cardiac surgery-associated AKI using novel biomarkers will result in improved outcomes. However, there is little evidence that interventions started early in the course of evolving AKI enhance renal recovery. Until effective therapies are developed that significantly improve the outcome from AKI, there is little benefit from early diagnosis using novel biomarkers. PMID:23441566

  6. Echo motion imaging with adaptive clutter filter for assessment of cardiac blood flow

    NASA Astrophysics Data System (ADS)

    Takahashi, Hiroki; Hasegawa, Hideyuki; Kanai, Hiroshi

    2015-07-01

    Visualization of the vortex blood flow in the cardiac chamber is a potential diagnostic tool for the evaluation of cardiac function. In the present study, a method for automatic selection of the desirable cutoff frequency of a moving target indicator filter, namely, a clutter filter, was proposed in order to visualize complex blood flows by the ultrahigh-frame-rate imaging of echoes from blood particles while suppressing clutter echoes. In this method, the cutoff frequency was adaptively changed as a function of the velocity of the heart wall (clutter source) in each frame. The feasibility of the proposed method was examined through the measurement of a healthy volunteer using parallel receive beamforming with a single transmission of a non-steered diverging beam. Using the moving target indicator filter as above with the cutoff frequency determined by the proposed method, the vortex-like blood flow in the cardiac chamber was visualized as movements of echoes from blood particles at a very high frame rate of 6024 Hz while suppressing clutter echoes.

  7. Assessment of Cardiac Functions in Infants with Cow’s Milk Allergy

    PubMed Central

    Ece, İbrahim; Demirören, Kaan; Demir, Nihat; Uner, Abdurrahman; Balli, Sevket

    2014-01-01

    Background Cow’s milk allergy is the most common food allergy in children, with rates estimated at 1.9% to 4.9%. Clinical phenotypes of cow’s milk allergy are varied and involve 1 or more target organs, with the main targets being the skin, respiratory system, and gastrointestinal tract. To date, no studies have investigated detailed cardiac function in children with cow’s milk allergy. The current study aimed to investigate cardiac function in infants with cow’s milk allergy. Material/Methods We studied 42 infants with cow’s milk allergy and 30 age- and sex-matched healthy subjects. Cardiac functions were evaluated by M-mode, pulsed-wave, and tissue Doppler echocardiography. Results There were no significant differences in ejection fraction or mitral and tricuspid annular plane systolic excursion between the 2 groups. Pulsed-wave Doppler-derived E/A ratios in mitral and tricuspid valves were similar in both groups. Ea/Aa ratios in the left ventricle posterior wall and right ventricle free wall were lower in patients with cow’s milk allergy than in the control group. The E/Ea ratio in the left ventricle, isovolumic relaxation time, deceleration time, and right and left ventricular myocardial performance indices were higher in patients in the study group. Conclusions Our study identified reduced early diastolic tissue Doppler velocities in infants with cow’s milk allergy. PMID:25098395

  8. Cardiac Catheterization

    MedlinePlus

    ... from the NHLBI on Twitter. What Is Cardiac Catheterization? Cardiac catheterization (KATH-eh-ter-ih-ZA-shun) is a ... disease. Doctors also can use ultrasound during cardiac catheterization to see blockages in the coronary arteries. Ultrasound ...

  9. How to Approach the Assessment of Cardiac Allograft Vasculopathy in the Modern Era: Review of Invasive Imaging Modalities.

    PubMed

    Javaheri, Ali; Saha, Naveen; Lilly, Scott M

    2016-04-01

    Heart transplantation is one of the most definitive therapies for end-stage heart failure. The therapy is unfortunately marred by the devastating complications of cardiac allograft vasculopathy (CAV). Non-invasive screening and assessment for CAV has been greatly limited by both low sensitivity and poor correlation with adverse outcomes. As such, invasive imaging with coronary angiography has emerged as the gold standard for detection of CAV. Although conventional coronary angiography serves well for larger lesions, the modality has been significantly enhanced with adjunct imaging to visualize the intimal hyperplasia that is a hallmark of the disease process. These modalities include intravascular ultrasound (IVUS) and optical coherence tomography (OCT). In the following review, we summarize both the invasive and non-invasive assessments of CAV. We further conclude that the current evidence poorly supports the use of non-invasive testing for early CAV and that a transition should be considered to routine early angiography with adjunctive intravascular imaging. PMID:26879390

  10. Ejection fraction assessment and survival: An analysis of the Sudden Cardiac Death in Heart Failure Trial (SCD-HeFT)

    PubMed Central

    Gula, Lorne J.; Klein, George J.; Hellkamp, Anne S.; Massel, David; Krahn, Andrew D.; Skanes, Allan C.; Yee, Raymond; Anderson, Jill; Johnson, George W.; Poole, Jeanne E.; Mark, Daniel B.; Lee, Kerry L.; Bardy, Gust H.

    2008-01-01

    Background Ejection fraction (EF) is an important method of mortality prediction among cardiac patients, and has been used to identify the highest risk patients for enrollment in the defibrillator primary prevention trials. Evidence suggests that measures of EF by different imaging modalities may not be equivalent. In the Sudden Cardiac Death in Heart Failure Trial (SCD-HeFT) the type of imaging modality for EF assessment was not mandated. Methods Baseline assessment of EF was performed using either echocardiography, radionuclide angiography (RNA), or contrast angiography. Multivariable analysis using a Cox proportional hazards model was used to examine whether the modality of assessing EF affected the likelihood of survival. Results Among the 2,521 patients enrolled in SCD-HeFT, EF was measured by RNA in 616 (24%), echocardiography in 1,469 (58%), and contrast angiography in 436 (17%). Mean EF as measured by RNA was 25.1 ± 6.9%, by echocardiography was 23.8 ± 6.9%, by and by angiography 21.9 ± 6.9%. These measures were significantly different (p<0.001) and each pair-wise comparison differed significantly (p<0.001 for each). Multivariable analysis showed no significant difference in survival between patients enrolled based on RNA versus echocardiography (hazard ratio 1.06, 95% CI: 0.88,1.28), RNA versus angiography (hazard ratio 1.25, 95% CI: 0.97,1.62), or echocardiography versus angiography (hazard ratio 1.18, 95% CI: 0.94,1.48). Conclusions Among patients enrolled in SCD-HeFT the distribution of ejection fractions measured by radionuclide angiography differed from those measured by echocardiography or contrast angiograms. Survival did not differ according to modality of EF assessment. PMID:19033019

  11. Georgia`s timber industry: An assessment of timber product output and use, 1995. Forest Service resource bulletin

    SciTech Connect

    Johnson, T.G.; Jenkins, A.; Wells, J.L.

    1997-05-01

    This report contains the findings of a 1995 canvass of all primary wood-using plants in Georgia and presents changes in product output and residue use since 1992. It complements the Forest Inventory and Analysis (FIA) periodic inventory of volume and removals from the State`s timberland. The canvass was conducted to determine the amount and source of wood receipts and annual timber product drain by county in 1995 and to determine interstate and cross-regional movement of industrial roundwood. Only primary wood-using mills were canvassed. Primary mills are those that process roundwood in log or bolt form or as chipped roundwood.

  12. South Carolina`s timber industry: An assessment of timber product output and use, 1995. Forest Service resource bulletin

    SciTech Connect

    Johnson, T.G.; Jenkins, A.; Stratton, D.P.; Bischoff, P.S.

    1997-05-01

    This report contains the findings of a 1995 canvass of all primary wood-using plants in South Carolina and presents changes in product output and residue use since 1994. It complements the Forest Inventory and Analysis (FIA) periodic inventory of volume and removals from the State`s timberland. The canvass was conducted to determine the amount and source of wood receipts and annual timber product drain by county in 1995 and to determine interstate and cross-regional movement of industrial roundwood. Only primary wood-using mills were canvassed. Primary mills are those that process roundwood in log or bolt form or as chipped roundwood.

  13. North Carolina`s timber industry: An assessment of timber product output and use, 1994. Forest Service resource bulletin

    SciTech Connect

    Johnson, T.G.; Brown, D.R.

    1996-03-01

    This report contains the findings of a 1994 canvas of all primary wood-using plants in North Carolina and presents changes in product output and residue use since 1992. It complements the Forest Inventory and Analysis periodic inventory of volume and removals from the State`s timberland. The canvass was conducted to determine the amount and source of wood receipts and annual timber product drain by county in 1994 and to determine interstate and cross-regional movement of industrial roundwood. Only primary wood-using mills were canvassed. Primary mills are those that process roundwood in log or bolt form or as chipped roundwood.

  14. Non-invasive cardiac imaging techniques and vascular tools for the assessment of cardiovascular disease in type 2 diabetes mellitus

    PubMed Central

    Beishuizen, E. D.; Pereira, A. M.; Rabelink, T. J.; Smit, J. W.; Tamsma, J. T.; Huisman, M. V.; Jukema, J. W.

    2008-01-01

    Cardiovascular disease is the major cause of mortality in type 2 diabetes mellitus. The criteria for the selection of those asymptomatic patients with type 2 diabetes who should undergo cardiac screening and the therapeutic consequences of screening remain controversial. Non-invasive techniques as markers of atherosclerosis and myocardial ischaemia may aid risk stratification and the implementation of tailored therapy for the patient with type 2 diabetes. In the present article we review the literature on the implementation of non-invasive vascular tools and cardiac imaging techniques in this patient group. The value of these techniques as endpoints in clinical trials and as risk estimators in asymptomatic diabetic patients is discussed. Carotid intima–media thickness, arterial stiffness and flow-mediated dilation are abnormal long before the onset of type 2 diabetes. These vascular tools are therefore most likely to be useful for the identification of ‘at risk’ patients during the early stages of atherosclerotic disease. The additional value of these tools in risk stratification and tailored therapy in type 2 diabetes remains to be proven. Cardiac imaging techniques are more justified in individuals with a strong clinical suspicion of advanced coronary heart disease (CHD). Asymptomatic myocardial ischaemia can be detected by stress echocardiography and myocardial perfusion imaging. The more recently developed non-invasive multi-slice computed tomography angiography is recommended for exclusion of CHD, and can therefore be used to screen asymptomatic patients with type 2 diabetes, but has the associated disadvantages of high radiation exposure and costs. Therefore, we propose an algorithm for the screening of asymptomatic diabetic patients, the first step of which consists of coronary artery calcium score assessment and exercise ECG. PMID:18607561

  15. Assessment of cardiac proteome dynamics with heavy water: slower protein synthesis rates in interfibrillar than subsarcolemmal mitochondria

    PubMed Central

    Dabkowski, Erinne R.; Shekar, Kadambari Chandra; Li, Ling; Ribeiro, Rogerio F.; Walsh, Kenneth; Previs, Stephen F.; Sadygov, Rovshan G.; Willard, Belinda; Stanley, William C.

    2013-01-01

    Traditional proteomics provides static assessment of protein content, but not synthetic rates. Recently, proteome dynamics with heavy water (2H2O) was introduced, where 2H labels amino acids that are incorporated into proteins, and the synthesis rate of individual proteins is calculated using mass isotopomer distribution analysis. We refine this approach with a novel algorithm and rigorous selection criteria that improve the accuracy and precision of the calculation of synthesis rates and use it to measure protein kinetics in spatially distinct cardiac mitochondrial subpopulations. Subsarcolemmal mitochondria (SSM) and interfibrillar mitochondria (IFM) were isolated from adult rats, which were given 2H2O in the drinking water for up to 60 days. Plasma 2H2O and myocardial 2H-enrichment of amino acids were stable throughout the experimental protocol. Multiple tryptic peptides were identified from 28 proteins in both SSM and IFM and showed a time-dependent increase in heavy mass isotopomers that was consistent within a given protein. Mitochondrial protein synthesis was relatively slow (average half-life of 30 days, 2.4% per day). Although the synthesis rates for individual proteins were correlated between IFM and SSM (R2 = 0.84; P < 0.0001), values in IFM were 15% less than SSM (P < 0.001). In conclusion, administration of 2H2O results in stable enrichment of the cardiac precursor amino acid pool, with the use of refined analytical and computational methods coupled with cell fractionation one can measure synthesis rates for cardiac proteins in subcellular compartments in vivo, and protein synthesis is slower in mitochondria located among the myofibrils than in the subsarcolemmal region. PMID:23457012

  16. Combining clinical and thallium data optimizes preoperative assessment of cardiac risk before major vascular surgery

    SciTech Connect

    Eagle, K.A.; Coley, C.M.; Newell, J.B.; Brewster, D.C.; Darling, R.C.; Strauss, H.W.; Guiney, T.E.; Boucher, C.A.

    1989-06-01

    STUDY OBJECTIVE: To determine whether clinical markers and preoperative dipyridamole-thallium imaging are both useful in predicting ischemic events after vascular surgery. Two hundred fifty-four consecutive patients were referred to a nuclear cardiology laboratory before surgery. Forty-four patients had surgery cancelled or postponed after clinical evaluation and dipyridamole-thallium imaging. Surgery was not confirmed for ten. Two hundred patients receiving prompt vascular surgery were the study group. Thirty patients (15%) had early postoperative cardiac ischemic events, with cardiac death in 6 (3%) and nonfatal myocardial infarction in 9 (4.5%). Logistic regression identified five clinical predictors (Q waves, history of ventricular ectopic activity, diabetes, advanced age, angina) and two dipyridamole-thallium predictors of postoperative events. Of patients with none of the clinical variables (n = 64), only 2 (3.1%; 95% CI, 0% to 8%) had ischemic events with no cardiac deaths. Ten of twenty (50%; 95% CI, 29% to 71%) patients with three or more clinical markers had events. Eighteen of one hundred sixteen (15.5%; 95% CI, 7% to 21%) patients with either 1 or 2 clinical predictors had events. Within this group, 2 of 62 (3.2%; 95% CI, 0% to 8%) patients without thallium redistribution had events compared with 16 events in 54 patients (29.6%; 95% CI, 16% to 44%) with thallium redistribution. The multivariate model using both clinical and thallium variables showed significantly higher specificity at equivalent sensitivity levels than models using either clinical or thallium variables alone. Preoperative dipyridamole-thallium imaging appears most useful to stratify vascular patients determined to be at intermediate risk by clinical evaluation.

  17. SVM-based classification of LV wall motion in cardiac MRI with the assessment of STE

    NASA Astrophysics Data System (ADS)

    Mantilla, Juan; Garreau, Mireille; Bellanger, Jean-Jacques; Paredes, José Luis

    2015-01-01

    In this paper, we propose an automated method to classify normal/abnormal wall motion in Left Ventricle (LV) function in cardiac cine-Magnetic Resonance Imaging (MRI), taking as reference, strain information obtained from 2D Speckle Tracking Echocardiography (STE). Without the need of pre-processing and by exploiting all the images acquired during a cardiac cycle, spatio-temporal profiles are extracted from a subset of radial lines from the ventricle centroid to points outside the epicardial border. Classical Support Vector Machines (SVM) are used to classify features extracted from gray levels of the spatio-temporal profile as well as their representations in the Wavelet domain under the assumption that the data may be sparse in that domain. Based on information obtained from radial strain curves in 2D-STE studies, we label all the spatio-temporal profiles that belong to a particular segment as normal if the peak systolic radial strain curve of this segment presents normal kinesis, or abnormal if the peak systolic radial strain curve presents hypokinesis or akinesis. For this study, short-axis cine- MR images are collected from 9 patients with cardiac dyssynchrony for which we have the radial strain tracings at the mid-papilary muscle obtained by 2D STE; and from one control group formed by 9 healthy subjects. The best classification performance is obtained with the gray level information of the spatio-temporal profiles using a RBF kernel with 91.88% of accuracy, 92.75% of sensitivity and 91.52% of specificity.

  18. Real time assessment of RF cardiac tissue ablation with optical spectroscopy

    SciTech Connect

    Demos, S G; Sharareh, S

    2008-03-20

    An optical spectroscopy approach is demonstrated allowing for critical parameters during RF ablation of cardiac tissue to be evaluated in real time. The method is based on incorporating in a typical ablation catheter transmitting and receiving fibers that terminate at the tip of the catheter. By analyzing the spectral characteristics of the NIR diffusely reflected light, information is obtained on such parameters as, catheter-tissue proximity, lesion formation, depth of penetration of the lesion, formation of char during the ablation, formation of coagulum around the ablation site, differentiation of ablated from healthy tissue, and recognition of micro-bubble formation in the tissue.

  19. Interarterial course of the right coronary artery: assessment with cardiac computed tomography and myocardial perfusion imaging.

    PubMed

    Husmann, Lars; Valenta, Ines; Veit-Haibach, Patrick; Alkadhi, Hatem; Largiader, Thomas; Kaufmann, Philipp A

    2008-05-01

    A 50-year-old well-trained cyclist reported increasing brief episodes of chest pain over the last 8 years at maximum exercise during alpine bicycle training. Previous cardiac stress testing on a supine bicycle ergometer revealed nonspecific ST-T abnormalities. In June 2007, the patient was referred for computed tomography coronary angiography, which revealed a coronary anomaly, with the right coronary artery originating from the left coronary sinus and taking an interarterial course between the ascending aorta and the pulmonary trunk. There were no atherosclerotic alterations in the coronary arteries. Subsequent bicycle exercise stress and myocardial perfusion imaging revealed no myocardial perfusion defect. PMID:18431148

  20. The biostability of cardiac lead insulation materials as assessed from long-term human implants.

    PubMed

    Wilkoff, Bruce L; Rickard, John; Tkatchouk, Ekaterina; Padsalgikar, Ajay D; Gallagher, Genevieve; Runt, James

    2016-02-01

    Accelerated in vitro biostability studies are useful for making relativistic comparisons between materials. However, no in vitro study can completely replicate the complex biochemical and biomechanical environment that a material experiences in the human body. To overcome this limitation, three insulation materials [Optim™ insulation (OPT), Pellethane® 55D (P55D), and silicone elastomer] from cardiac leads that were clinically implanted for up to five years were characterized using visual inspection, SEM, ATR-FTIR, GPC, and tensile testing. Surface cracking was not observed in OPT or silicone samples. Shallow cracking was observed in 17/41 (41%) explanted P55D samples. ATR-FTIR indicated minor surface oxidation in some OPT and P55D samples. OPT molecular weight decreased modestly (∼20%) at 2-3 years before stabilizing at 4-5 years. OPT tensile strength decreased modestly (∼25%) at 2-3 years before stabilizing at 4-5 years. OPT elongation at 4-5 years was unchanged from controls. P55D had no significant changes in molecular weight or tensile properties. Overall, results for OPT and P55D were consistent with and limited to cosmetic surface oxidation. Silicone demonstrated excellent biostability with no identifiable degradation. This study of explanted cardiac leads revealed that OPT, P55D, and silicone elastomer demonstrate similar and excellent biostability through five years of implantation in human patients. PMID:25891020

  1. Assessment of total cardiac repolarization’s spatial distribution among patients with aortic sclerosis

    PubMed Central

    Turan, Oguzhan Ekrem; Ozturk, Mustafa; Ilter, Abdulselam; Inc, Mustafa; Karaman, Kayihan; Kiris, Gulhanim; Kutlu, Merih

    2015-01-01

    Objective: To measure the Tp-e value, which shows the spatial distribution of cardiac repolarization and is defined as a possible predictor for ventricular arrhythmia among patients with aortic sclerosis (AS), and to compare this parameter’s length to QTc length within the same population. Method: 60 patients that have been diagnosed with AS have been prospectively included in this study. Results: 60 AS and 64 control patients were evaluated as part of the study. The median age, prevalence for hypertension and diabetes, baseline medications and laboratory results of the groups were similar. The Electrocardiographic QT length of both groups were found similar. In the AS group Tp-e tangent and Tp-e tail values were more longer than control group (P < 0.001). Tp-e tangent index and Tp-e tail index values were also statistically higher among AS patients when compared to the control group. (P < 0.001). Conclusion: Our study showed that Tp-e durations had increased in AS patients with no structural coronary heart disease. AS causes local degeneration on the aortic root and also has a negative effect on the total cardiac spatial repolarization. PMID:26064308

  2. Mission-Driven Expected Impact: Assessing Scholarly Output for 2013 Association to Advance Collegiate Schools of Business Standards

    ERIC Educational Resources Information Center

    Goulet, Laurel R.; Lopes, Kevin J.; White, John Bryan

    2016-01-01

    As of the 2016-2017 academic year, all schools undergoing Association to Advance Collegiate Schools of Business accreditation will be assessed on the new standards that were ratified in 2013, which include the assessment of the impact of portfolios of intellectual contributions. The authors discuss key ideas underlying a business school's research

  3. Mission-Driven Expected Impact: Assessing Scholarly Output for 2013 Association to Advance Collegiate Schools of Business Standards

    ERIC Educational Resources Information Center

    Goulet, Laurel R.; Lopes, Kevin J.; White, John Bryan

    2016-01-01

    As of the 2016-2017 academic year, all schools undergoing Association to Advance Collegiate Schools of Business accreditation will be assessed on the new standards that were ratified in 2013, which include the assessment of the impact of portfolios of intellectual contributions. The authors discuss key ideas underlying a business school's research…

  4. Southeast`s timber industry: An assessment of timber product output and use, 1995. Forest Service resource bulletin

    SciTech Connect

    Johnson, T.G.

    1998-01-01

    This report contains the findings of a 1995 canvass of all primary wood-using plants in the Southeast and presents changes in product output and residue use since 1992. It complements the Forest Inventory and Analysis periodic inventory of volume and removals from the timberland in Southeastern States. The canvass was conducted to determine the amount and source of wood receipts and annual timber product drain by county in 1995 and to determine interstate and cross-regional movement of industrial roundwood. Only primary wood-using mills were canvassed. Primary mills are those that process roundwood in log or bolt form or as chipped roundwood. Examples of industrial roundwood products are saw logs, pulpwood, veneer logs, poles, and logs used for composite board products.

  5. Assessing the long-term performance of terrestrial ecosystem models in northeastern United States: linking model structure and output

    NASA Astrophysics Data System (ADS)

    Liu, Y.; Matthes, J. H.; Moore, D. J.; Dietze, M.; Arellano, A. F.; Dawson, A.; Fox, A. M.; Goring, S. J.; McLachlan, J. S.; Montane, F.; Moreno, G.; Poulter, B.; Quaife, T. L.; Ricciuto, D. M.; Schaefer, K. M.; Steinkamp, J.; Williams, J. W.; Team, P.

    2014-12-01

    Terrestrial biosphere models are being used to forecast ecosystem response to future climate change. However, the predictions of these models do not agree, and their ability to accurately represent decadal- and longer-scale ecological processes has rarely been tested. Here we investigate how the structure of the terrestrial biosphere models affects their ability to accurately simulate vegetation dynamics over the past 1000 years. Six models and model variations are involved, including the Ecosystem Demography 2 model (ED2), the Community Land Model (CLM4.0, CLM4.5, CLM4.5-dynamic vegetation), and the Lund-Postdam-Jena models (LPJ-GUESS and LPJ-wsl). Using common paleoclimatic drivers and modeling protocols, we simulated vegetation changes in the northeastern US with these models for the past 1000 years. We compared the model outputs with paleoecological/historical benchmark datasets (paleo-vegetation data reconstructed from fossil pollen records and pre-EuroAmerican vegetation data from the Public Land Survey and Town Proprietor Surveys) to evaluate model performance. We characterized the models based on how they represented photosynthesis, water relations, soil, biogeochemical cycling, and vegetation dynamics. Models with similar structures behaved more similarly over time; we found that model attributes of both fast (e.g. photosynthesis) and slow processes (e.g. vegetation dynamics) affect model long-term predictions. However, the effect of model attributes varies among regions and across time. In addition to model structure, parameter uncertainty among models also appears to contribute to the differences in model output. We are currently working on assimilating paleoecological data into a subset of the terrestrial biosphere models to constrain the key model parameters and state variables, and in turn, to better evaluate the effect of model structure alone on model performance.

  6. [Cardiac neuroses].

    PubMed

    Simson, U; Martin, K; Janssen, P L

    2001-09-01

    Cardiac neurosis is defined as heart complaints for which no organic cause can be found. Other common terms are "cardiac anxiety neurosis", "cardiac anxiety disorder", "cardiac phobia", "functional heart complaints" and "somatoform autonomous functional disorders of the cardiovascular system" (ICD-10). Although cardiac neurosis is rarely diagnosed, it is estimated that approximately 30 bis 40% of patients with cardiovascular disorders are actually suffering from functional complaints. Predisposing to the development of cardiac neurosis are insufficient internalization processes during childhood, leading to an insoluble autonomy dependency conflict. Cardiac neurosis is treated with drugs and psychotherapy. PMID:11554103

  7. Assessment of nonpenetrating captive bolt stunning followed by electrical induction of cardiac arrest in veal calves.

    PubMed

    Bartz, B; Collins, M; Stoddard, G; Appleton, A; Livingood, R; Sobcynski, H; Vogel, K D

    2015-09-01

    The purpose of this study was to evaluate the impact of nonpenetrating captive bolt stunning followed by electrical induction of cardiac arrest on veal calf welfare, veal quality, and blood yield. Ninety calves from the same farm were randomly assigned to 1 of 2 treatment groups in a balanced unpaired comparison design. The first treatment group (the "head-only" method-application of the pneumatic nonpenetrating stun to the frontal plate of the skull at the intersection of 2 imaginary lines extending from the lateral canthus to the opposite poll [CONTROL]) was stunned with a nonpenetrating captive bolt gun ( = 45). The second group ( = 45) was stunned with a nonpenetrating captive bolt gun followed by secondary electrical induction of cardiac arrest (the "head/heart" method-initial application of the pneumatic nonpenetrating captive bolt stun followed by 1 s application of an electrical stun to the ventral region of the ribcage directly caudal to the junction of the humerus and scapula while the stunned calf was in lateral recumbence [HEAD/HEART]). Stunning efficacy was the indicator of animal welfare used in this study. All calves were instantly rendered insensible by the initial stun and did not display common indicators of return to consciousness. For meat quality evaluation, all samples were collected from the 12th rib region of the longissimus thoracis. Meat samples were evaluated for color, drip loss, ultimate pH, cook loss, and Warner-Bratzler shear force. The L* values (measure of meat color lightness) were darker ( < 0.05) in the HEAD/HEART group (45.08 ± 0.72) than the CONTROL group (47.10 ± 0.72). There were no differences ( > 0.05) observed in a* (redness) and b* (yellowness) values between treatments. No differences ( > 0.05) were observed in drip loss, ultimate pH, cook loss, and Warner-Bratzler shear force. The blood yield from the CONTROL group (7,217.9 ± 143.5 g) was greater ( < 0.05) than that from the HEAD/HEART group (6,656.4 ± 143.5 g). Overall, the data indicated no difference between the CONTROL and HEAD/HEART groups with regard to animal welfare because the initial stun was effective in all calves. However, longissimus thoracis L* and blood yield were negatively impacted by the HEAD/HEART method. The data in this study suggest that secondary induction of cardiac arrest is not necessary with effective nonpenetrating captive bolt stunning in veal calves. PMID:26440354

  8. The Role of Magnetic Resonance Imaging and Cardiac Computed Tomography in the Assessment of Left Atrial Anatomy, Size, and Function

    PubMed Central

    Kuchynka, Petr; Podzimkova, Jana; Masek, Martin; Lambert, Lukas; Cerny, Vladimir; Danek, Barbara; Palecek, Tomas

    2015-01-01

    In the last decade, there has been increasing evidence that comprehensive evaluation of the left atrium is of utmost importance. Numerous studies have clearly demonstrated the prognostic value of left atrial volume for long-term outcome. Furthermore, advances in catheter ablation procedures used for the treatment of drug-refractory atrial fibrillation require the need for detailed knowledge of left atrial and pulmonary venous morphology as well of atrial wall characteristics. This review article discusses the role of cardiac magnetic resonance and computed tomography in assessment of left atrial size, its normal and abnormal morphology, and function. Special interest is paid to the utility of these rapidly involving noninvasive imaging methods before and after atrial fibrillation ablation. PMID:26221583

  9. Tools for assessing quality of life in cardiology and cardiac surgery

    PubMed Central

    Pudlo, Robert; Jaworska, Izabela; Byrczek-Godula, Kamila; Gąsior, Mariusz

    2016-01-01

    The holistic concept of health, popularization of knowledge, as well as social and economic factors have contributed to the growing interest in research concerning quality of life in cardiovascular diseases. The value of direct measurements of the patient's well-being and the extent of their functioning in everyday life (i.e., health-related quality of life; HRQoL) has gained appreciation. Questionnaires are the most popular method of measuring quality of life. On the basis of the literature, we can conclude that the Short-Form Health Survey (SF-36) questionnaire is one of the most widely used tools measuring the quality of life of patients undergoing cardiological treatment and cardiac surgery.

  10. Safety assessment and biodistribution of povidone as a coating material for cardiac pacing leads

    SciTech Connect

    Jay, M.; Digenis, G.A.

    1983-01-01

    Cardiac pacing leads coated with povidone-(/sup 131/I) were implanted in dogs and the leaching of radioactivity from the leads was monitored by external scintigraphy. The activity which had dissipated from the pacing leads was not as (/sup 131/I)-iodide, but as povidone-(/sup 131/I). Only 50% (mean) of the activity remained on the pacing leads after two weeks while a significant amount of radioactivity was eliminated via urine and feces. The liver was a major site of accumulation of retained activity which had leached off the pacing leads. There was no evidence of large pieces of povidone-(/sup 131/I) in the lungs of the dogs, all of which appeared healthy at the time of sacrifice. The results of this study support the conclusions of a long-term study indicating that povidone is a safe and suitable coating material for pacing leads.

  11. On-chip assessment of human primary cardiac fibroblasts proliferative responses to uniaxial cyclic mechanical strain.

    PubMed

    Ugolini, Giovanni Stefano; Rasponi, Marco; Pavesi, Andrea; Santoro, Rosaria; Kamm, Roger; Fiore, Gianfranco Beniamino; Pesce, Maurizio; Soncini, Monica

    2016-04-01

    Cardiac cell function is substantially influenced by the nature and intensity of the mechanical loads the cells experience. Cardiac fibroblasts (CFs) are primarily involved in myocardial tissue remodeling: at the onset of specific pathological conditions, CFs activate, proliferate, differentiate, and critically alter the amount of myocardial extra-cellular matrix with important consequences for myocardial functioning. While cyclic mechanical strain has been shown to increase matrix synthesis of CFs in vitro, the role of mechanical cues in CFs proliferation is unclear. We here developed a multi-chamber cell straining microdevice for cell cultures under uniform, uniaxial cyclic strain. After careful characterization of the strain field, we extracted human heart-derived CFs and performed cyclic strain experiments. We subjected cells to 2% or 8% cyclic strain for 24 h or 72 h, using immunofluorescence to investigate markers of cell morphology, cell proliferation (Ki67, EdU, phospho-Histone-H3) and subcellular localization of the mechanotransduction-associated transcription factor YAP. Cell morphology was affected by cyclic strain in terms of cell area, cell and nuclear shape and cellular alignment. We additionally observed a strain intensity-dependent control of cell growth: a significant proliferation increase occurred at 2% cyclic strain, while time-dependent effects took place upon 8% cyclic strain. The YAP-dependent mechano-transduction pathway was similarly activated in both strain conditions. These results demonstrate a differential effect of cyclic strain intensity on human CFs proliferation control and provide insights into the YAP-dependent mechano-sensing machinery of human CFs. Biotechnol. Bioeng. 2016;113: 859-869. © 2015 Wiley Periodicals, Inc. PMID:26444553

  12. Prevalence of troponin elevations in patients with cardiac arrest and implications for assessing quality of care in hypothermia centers.

    PubMed

    Kontos, Michael C; Ornato, Joseph P; Kurz, Michael C; Roberts, Charlotte S; Gossip, Michelle; Dhindsa, Harinder S; Reid, Renee D; Peberdy, Mary A

    2013-10-01

    The prevalence of troponin elevations in patients with cardiac arrest (CA) using newer generation troponin assays when the ninety-ninth percentile is used has not been well described. We studied patients admitted with CA without ST elevation myocardial infarction (MI). Treatment included a multidisciplinary protocol that included routine use of hypothermia for appropriate patients. Serial assessment of cardiac biomarkers, including troponin I was obtained over the initial 24 to 36 hours. Patients were classified into 1 of 5 groups on the basis of multiples of the ninety-ninth percentile (upper reference limit [URL]), using the peak troponin I value: <1×, 1 to 3×, 3 to 5×, 5 to 10×, and >10×. Serial changes between the initial and second troponin I values were also assessed. A total of 165 patients with CA (mean age 58 ± 16, 67% men) were included. Troponin I was detectable in all but 2 patients (99%); all others had peak troponin I values that were greater than or equal to the URL. Most patients had peak troponin I values >10× URL, including patients with ventricular fibrillation or ventricular tachycardia (85%), asystole (50%), and pulseless electrical activity (59%). Serial changes in troponin I were present in almost all patients: ≥20% change in 162 (98%), ≥30% change in 159 (96%), and an absolute increase of ≥0.02 ng/ml in 85% of patients. In conclusion, almost all patients with CA who survived to admission had detectable troponin I, most of whom met biomarker guideline criteria for MI. Given the high mortality of these patients, these data have important implications for MI mortality reporting at CA treatment centers. PMID:23800547

  13. Application of Lidar Data in the Assessment of Observed and Model Output Temperature Soundings During the Pacific 2001 Field Study.

    NASA Astrophysics Data System (ADS)

    Strawbridge, K. B.; Snyder, B. J.

    2002-12-01

    Surface and airborne lidar, along with upper air soundings and model derived soundings were examined over the course of the Pacific 2001 Air Quality Field Study. The general region of interest in this report is the Georgia Basin with a focus on the Lower Fraser Valley of British Columbia. Data included the following: RASCAL (Rapid Acquisition SCanning Aerosol Lidar), a surface-based scanning lidar facility at the Langley Lochiel site, operating close to 16 hours each day; AERIAL (AERosol Imaging Airborne Lidar), a simultaneous upward/downward airborne lidar system providing 9 flights during the field study; radiosondes, released 4 times daily from the Langley Poppy site; and once-daily 3.3 km resolution MC2 (Mesoscale Compressible Community weather prediction) model output. Methods of diagnosing mixing heights amongst the various datasets are outlined. The higher resolution lidar data provides a means of calibrating mixing heights from radiosondes and also allows a means of evaluating model derived soundings. Results show that in most cases there is good agreement amongst the various sources of data. This data is then used to demonstrate the variation of mixing height with sea breeze activity over the Lower Fraser Valley.

  14. Aerobic exercise intensity assessment and prescription in cardiac rehabilitation: a joint position statement of the European Association for Cardiovascular Prevention and Rehabilitation, the American Association of Cardiovascular and Pulmonary Rehabilitation and the Canadian Association of Cardiac Rehabilitation.

    PubMed

    Mezzani, Alessandro; Hamm, Larry F; Jones, Andrew M; McBride, Patrick E; Moholdt, Trine; Stone, James A; Urhausen, Axel; Williams, Mark A

    2013-06-01

    Aerobic exercise intensity prescription is a key issue in cardiac rehabilitation, being directly linked to both the amount of improvement in exercise capacity and the risk of adverse events during exercise. This joint position statement aims to provide professionals with up-to-date information regarding the identification of different exercise intensity domains, the methods of direct and indirect determination of exercise intensity for both continuous and interval aerobic training, the effects of the use of different exercise protocols on exercise intensity prescription and the indications for recommended exercise training prescription in specific cardiac patients' groups. The importance of functional evaluation through exercise testing prior to starting an aerobic training program is strongly emphasized, and ramp incremental cardiopulmonary exercise test, when available, is proposed as the gold standard for a physiologically comprehensive exercise intensity assessment and prescription. This may allow a shift from a 'range-based' to a 'threshold-based' aerobic exercise intensity prescription, which, combined with thorough clinical evaluation and exercise-related risk assessment, could maximize the benefits obtainable by the use of aerobic exercise training in cardiac rehabilitation. PMID:23104970

  15. Absorbed dose assessment of cardiac and other tissues around the cardiovascular system in brachytherapy with 90Sr/90Y source by Monte Carlo simulation.

    PubMed

    Saghamanesh, S; Karimian, A; Abdi, M

    2011-09-01

    Cardiac disease is one of the most important causes of death in the world. Coronary artery stenosis is a very common cardiac disease. Intravascular brachytherapy (IVBT) is one of the radiotherapy methods which have been used recently in coronary artery radiation therapy for the treatment of restenosis. (90)Sr/(90)Y, a beta-emitting source, is a proper option for cardiovascular brachytherapy. In this research, a Monte Carlo simulation was done to calculate dosimetry parameters and effective equivalent doses to the heart and its surrounding tissues during IVBT. The results of this study were compared with the published experimental data and other simulations performed by different programs but with the same source of radiation. A very good agreement was found between results of this work and the published data. An assessment of the risk for cardiac and other sensitive soft tissues surrounding the treated vessel during (90)Sr/(90)Y IVBT was also performed in the study. PMID:21831866

  16. Optical coherence tomography provides an ability to assess mechanical property of cardiac wall of developing outflow tract in embryonic heart in vivo

    NASA Astrophysics Data System (ADS)

    Li, Peng; Wang, Ruikang K.

    2012-12-01

    Knowledge of the biomechanical/elastic property of the cardiac wall is of fundamental importance in improving our understanding of cardiac development, particularly the interaction between the wall dynamics and hemodynamics in the developing outflow tract (OFT). We describe a method that employs optical coherence tomography (OCT) as a means to noninvasively measure the local elastic property of the cardiac wall in vivo. The method uses a time-lapse sequence of OCT images that represent the dynamic behavior of the OFT longitudinal section to calculate the regional wall pulse wave velocity (PWV), upon which the Young's modulus of the cardiac wall is deduced by the use of the Moens-Korteweg equation. The experimental results show that the foot-to-foot PWV ranges from 3.2 to 6.6 mm/s with a mean of 4.7 mm/s, and the averaged Young's modulus is 0.36 Pa, both of which are comparable to the documented values of stage HH17 atrioventricular canal tissue. The proposed method that provides the quantitative mechanical assessment may play a significant role in the understanding of the cardiac development.

  17. A thorough QT study to assess the effects of tbo-filgrastim on cardiac repolarization in healthy subjects

    PubMed Central

    Adar, Liat; Avisar, Noa; Lammerich, Andreas; Kleiman, Robert B; Spiegelstein, Ofer

    2015-01-01

    Tbo-filgrastim is a recombinant human granulocyte colony-stimulating factor approved by the US Food and Drug Administration to reduce the duration of severe neutropenia in patients with nonmyeloid malignancies receiving myelosuppressive anticancer drugs associated with a clinically significant incidence of febrile neutropenia. We assessed the effect of tbo-filgrastim on cardiac conduction and repolarization in healthy subjects. A three-arm, parallel-group, active- and placebo-controlled, double-blind study randomized healthy adults to a single 5 μg/kg intravenous tbo-filgrastim infusion, a single intravenous placebo infusion, or a single 400 mg moxifloxacin oral dose. The primary end point was placebo-corrected time-matched change from baseline in QT interval corrected using a QT individual correction (QTcI) method. Secondary end points included heart rate, PR interval, QRS duration, change in electrocardiogram patterns, correlation between QTcI change from baseline (milliseconds) and tbo-filgrastim serum concentrations, and safety variables. A total of 145 subjects were enrolled (50 tbo-filgrastim, 50 placebo, 45 moxifloxacin). Peak placebo-corrected change from baseline for QTcI with tbo-filgrastim was 3.5 milliseconds, with a two-sided 95% upper confidence interval of 7.2 milliseconds, demonstrating no signal for any tbo-filgrastim effect on QTc. Concentration-effect modeling showed no evidence of an effect of tbo-filgrastim on cardiac repolarization. Tbo-filgrastim produced no clinically significant changes in other electrocardiogram parameters. Tbo-filgrastim was well tolerated. PMID:26028962

  18. Quantitative Assessment of Artifacts on Cardiac Magnetic Resonance Imaging of Patients with Pacemakers and Implantable Cardioverter Defibrillators

    PubMed Central

    Sasaki, Takeshi; Hansford, Rozann; Zviman, Menekhem M; Kolandaivelu, Aravindan; Bluemke, David A; Berger, Ronald D; Calkins, Hugh; Halperin, Henry R; Nazarian, Saman

    2011-01-01

    Background The safety and clinical utility of magnetic resonance imaging at 1.5T in patients with cardiac implantable devices such as pacemakers (PM) and implantable cardioverter defibrillators (ICD) have been reported. This study aims to evaluate the extent of artifacts on cardiac magnetic resonance (CMR) in patients with PM and ICD (PM/ICD). Methods and Results A total of 71 CMR studies were performed with an established safety protocol in patients with pre-pectoral PM/ICD. The artifact area around the PM/ICD generator was measured in all short axis (SA), horizontal (HLA) and vertical long axis (VLA) SSFP cine planes. The location and extent of artifacts were also assessed in all SA (20 sectors/plane), HLA, and VLA (6 sectors/plane) late gadolinium enhanced CMR (LGE-CMR) planes. The artifact area on cine CMR was significantly larger with ICD versus PM generators in each plane (P<0.001, respectively). In patients with left-sided ICD or biventricular ICD systems, the percentages of sectors with any artifacts on LGE-CMR were 53.7%, 48.0% and 49.2% in SA, HLA and VLA planes, respectively. Meanwhile, patients with left-sided PM or right-sided PM/ICD had fewer artifacts. Anterior and apical regions were severely affected by artifact due to left-sided PM/ICD generators. Conclusions In contrast to patients with right-sided PM/ICD and left-sided PM, the anterior and apical left ventricle can be affected by susceptibility artifacts in patients with left-sided ICD. Artifact reduction methodologies will be necessary to improve the performance of CMR in patients with left sided ICD systems. PMID:21946701

  19. Protocol for the China PEACE (Patient-centered Evaluative Assessment of Cardiac Events) Million Persons Project pilot

    PubMed Central

    Lu, Jiapeng; Xuan, Si; Downing, Nicholas S; Wu, Chaoqun; Li, Li; Krumholz, Harlan M; Jiang, Lixin

    2016-01-01

    Introduction Collection of high-quality data from large populations is considered essential to generate knowledge that is critical to an era of precision medicine. Cardiovascular disease (CVD) is a leading cause of mortality in China and is a suitable focus of an initiative to discover factors that would improve our ability to assess and modify individual risk. Methods and analysis The pilot phase of China PEACE (Patient-centered Evaluative Assessment of Cardiac Events) Million Persons Project is being conducted during 2014–2015 in four provinces across China to demonstrate the feasibility of a population-based assessment. It is designed to screen 0.4 million community-dwelling residents aged 40–75 years with measurements of blood pressure, height and weight, a lipid blood test, and a questionnaire on cardiovascular-related health status. Participants identified at high risk of CVD receive further health assessments, including ECG, ultrasound scan, blood and urine analysis, and a questionnaire on lifestyle and medical history. Collection of blood and urine samples is used to establish a biobank. High-risk subjects are also counselled with suggestions regarding potential lifestyle changes. In addition, high-risk subjects are followed-up either in a return clinic visit or by telephone interview, with measurement of blood pressure, weight, ECG, and a questionnaire on survival status, hospitalisations and lifestyle. The first 0.1 million participants screened were used to conduct a preliminary analysis, with information on baseline characteristics, health-related behaviours, anthropometric variables, medical history, and prevalence of high-risk subjects. Ethics and dissemination The central ethics committee at the China National Center for Cardiovascular Disease (NCCD) approved the pilot. Written informed consent is obtained from all participants on entry into the project. Findings will be disseminated in future peer-reviewed papers and will inform strategies aimed at developing precise methods of assessing and modifying risk. Trial registration number NCT02536456. PMID:26729395

  20. Cardiac Assessment Risk Evaluation (Care Study) of African American College Women

    ERIC Educational Resources Information Center

    Brown, Sandra C.; Geiselman, Paula J.; Copeland, Amy L.; Gordon, Carol; Dudley, Mary; Manogin, Toni; Backstedt, Carol; Pourciau, Cathi; Ghebretatios, Ghenet

    2005-01-01

    Objective: To identify physiological and psychosocial variables of young African American women that may serve as a risk factor for heart disease and to assess their health promotion programme preferences. Method: A descriptive design was used to assess the cardiovascular risk factors of 100 African American women ages 18 to 40 years, enrolled in…

  1. Cardiac Assessment Risk Evaluation (Care Study) of African American College Women

    ERIC Educational Resources Information Center

    Brown, Sandra C.; Geiselman, Paula J.; Copeland, Amy L.; Gordon, Carol; Dudley, Mary; Manogin, Toni; Backstedt, Carol; Pourciau, Cathi; Ghebretatios, Ghenet

    2005-01-01

    Objective: To identify physiological and psychosocial variables of young African American women that may serve as a risk factor for heart disease and to assess their health promotion programme preferences. Method: A descriptive design was used to assess the cardiovascular risk factors of 100 African American women ages 18 to 40 years, enrolled in

  2. Assessment of the role of the renin-angiotensin system in cardiac contractility utilizing the renin inhibitor remikiren.

    PubMed Central

    van Kats, J. P.; Sassen, L. M.; Danser, A. H.; Polak, M. P.; Soei, L. K.; Derkx, F. H.; Schalekamp, M. A.; Verdouw, P. D.

    1996-01-01

    1. The role of the renin-angiotensin system in the regulation of myocardial contractility is still debated. In order to investigate whether renin inhibition affects myocardial contractility and whether this action depends on intracardiac rather than circulating angiotensin II, the regional myocardial effects of systemic (i.v.) and intracoronary (i.c.) infusions of the renin inhibitor remikiren, were compared and related to the effects on systemic haemodynamics and circulating angiotensin II in open-chest anaesthetized pigs (25-30 kg). The specificity of the remikiren-induced effects was tested (1) by studying its i.c. effects after administration of the AT1-receptor antagonist L-158,809 and (2) by measuring its effects on contractile force of porcine isolated cardiac trabeculae. 2. Consecutive 10 min i.v. infusions of remikiren were given at 2, 5, 10 and 20 mg min-1. Mean arterial pressure (MAP), cardiac output (CO), heart rate (HR), systemic vascular resistance (SVR), myocardial oxygen consumption (MVO2) and left ventricular (LV) dP/dtmax were not affected by remikiren at 2 and 5 mg min-1, and were lowered at higher doses. At the highest dose, MAP decreased by 48%, CO by 13%, HR by 14%, SVR by 40%, MVO2 by 28% and LV dp/dtmax by 52% (mean values; P < 0.05 for difference from baseline, n = 5). The decrease in MVO2 was accompanied by a decrease in myocardial work (MAP x CO), but the larger decline in work (55% vs. 28%; P < 0.05) implies a reduced myocardial efficiency ((MAP x CO)/MVO2). 3. Consecutive 10 min i.c. infusions of remikiren were given at 0.2, 0.5, 1, 2, 5 and 10 mg min-1. MAP, CO, MVO2 and LV dP/dtmax were not affected by remikiren at 0.2, 0.5 and 1 mg min-1, and were reduced at higher doses. At the highest dose, MAP decreased by 31%, CO by 26%, MVO2 by 46% and LV dP/dtmax by 43% (mean values; P < 0.05 for difference from baseline, n = 6). HR and SVR did not change at any dose. 4. Thirty minutes after a 10 min i.v. infusion of the AT1 receptor antagonist, L-158,809 at 1 mg min-1, consecutive 10 min i.c. infusions (n = 5) of remikiren at 2, 5 and 10 mg min-1 no longer affected CO and MVO2, and decreased LV dP/dtmax by maximally 27% (P < 0.05) and MAP by 14% (P < 0.05), which was less than without AT1-receptor blockade (P < 0.05). HR and SVR remained unaffected. 5. Plasma renin activity and angiotensin I and II were reduced to levels at or below the detection limit at doses of remikiren that were not high enough to affect systemic haemodynamics or regional myocardial function, both after i.v. and i.c. infusion. 6. Remikiren (10(-10) to 10(-4) M) did not affect contractile force of porcine isolated cardiac trabeculae precontracted with noradrenaline. In trabeculae that were not precontracted no decrease in baseline contractility was observed with remikiren in concentrations up to 10(-5) M, whereas at 10(-4) M baseline contractility decreased by 19% (P < 0.05). 7. Results show that with remikiren i.v., at the doses we used, blood pressure was lowered primarily by vasodilation and with remikiren i.c. by cardiac depression. The blood levels of remikiren required for its vasodilator action are lower than the levels affecting cardiac contractile function. A decrease in circulating angiotensin II does not appear to be the sole explanation for these haemodynamic responses. Data support the contention that myocardial contractility is increased by renin-dependent angiotensin II formation in the heart. PMID:8851507

  3. Cardiac arrest

    MedlinePlus

    Sudden cardiac arrest, SCA; Cardiopulmonary arrest; Circulatory arrest ... While some people refer to a heart attack as a cardiac arrest, they are not the same thing. A heart attack occurs when a blocked artery stops the flow ...

  4. Cardiac rehabilitation

    MedlinePlus

    Cardiac rehabilitation (rehab) is a program that helps you live better with heart disease. It is often prescribed to ... Ades PA, et al. Core Components of Cardiac Rehabilitation/Secondary Prevention Programs: 2007 Update: A Scientific Statement ...

  5. Unrecognized Myocardial Infarction Assessed by Cardiac Magnetic Resonance Imaging – Prognostic Implications

    PubMed Central

    Ahlström, Håkan; Bjerner, Tomas; Duvernoy, Olov; Eggers, Kai M.; Fröbert, Ole; Hadziosmanovic, Nermin

    2016-01-01

    Background Clinically unrecognized myocardial infarctions (UMI) are not uncommon and may be associated with adverse outcome. The aims of this study were to determine the prognostic implication of UMI in patients with stable suspected coronary artery disease (CAD) and to investigate the associations of UMI with the presence of CAD. Methods and Findings In total 235 patients late gadolinium enhancement cardiovascular magnetic resonance (LGE-CMR) imaging and coronary angiography were performed. For each patient with UMI, the stenosis grade of the coronary branch supplying the infarcted area was determined. UMIs were present in 25% of the patients and 67% of the UMIs were located in an area supplied by a coronary artery with a stenosis grade ≥70%. In an age- and gender-adjusted model, UMI independently predicted the primary endpoint (composite of death, myocardial infarction, resuscitated cardiac arrest, hospitalization for unstable angina pectoris or heart failure within 2 years of follow-up) with an odds ratio of 2.9; 95% confidence interval 1.1–7.9. However, this association was abrogated after adjustment for age and presence of significant coronary disease. There was no difference in the primary endpoint rates between UMI patients with or without a significant stenosis in the corresponding coronary artery. Conclusions The presence of UMI was associated with a threefold increased risk of adverse events during follow up. However, the difference was no longer statistically significant after adjustments for age and severity of CAD. Thus, the results do not support that patients with suspicion of CAD should be routinely investigated by LGE-CMR for UMI. However, coronary angiography should be considered in patients with UMI detected by LGE-CMR. Trial Registration ClinicalTrials.gov NTC01257282 PMID:26885831

  6. Source location of air pollution and cardiac autonomic function: trajectory cluster analysis for exposure assessment.

    PubMed

    Park, Sung Kyun; O'Neill, Marie S; Stunder, Barbara J B; Vokonas, Pantel S; Sparrow, David; Koutrakis, Petros; Schwartz, Joel

    2007-08-01

    Although many studies report that exposure to air pollution harms health, few have examined associations between pollution sources and health outcomes. We hypothesized that pollution originating in different locations has different associations with heart rate variability (HRV) among 497 men from the Normative Aging Study in Boston, Massachusetts. We identified the paths that air masses traveled ('back-trajectories') before arriving in Boston on the days the men were examined. Next, we classified these trajectories into six clusters. We examined whether the association of measured air pollutants with HRV (standard deviation of normal-to-normal intervals, high-frequency power (HF) and low-frequency power (LF), and LF/HF ratio) differed by cluster. We also examined whether the clusters alone (not considering air pollution measurements) showed different associations with HRV. The effects of black carbon (BC) on all HRV measures were strongest on days with southwest trajectories. Subjects who were examined on days where air parcels came from west had the strongest associations with ozone. All particle pollutants (particulate matter <2.5 microm in aerodynamic diameter (PM2.5), BC, and sulfates) were associated with increased LF/HF ratio on days with relatively short trajectories, which are related to local, slow-moving air masses. We also observed significant increases in LF/HF in days where air came from the northwest and west, compared to north trajectory days. Health effects associated with exposure to air pollution can be evaluated using pollutant concentrations as well as aspects of the pollution mixture captured by identifying locations where air masses originate. Independent effects of both these indicators of pollution exposure were seen on cardiac autonomic function. PMID:17299527

  7. In Vivo Quantitative Assessment of Myocardial Structure, Function, Perfusion and Viability Using Cardiac Micro-computed Tomography

    PubMed Central

    van Deel, Elza; Ridwan, Yanto; van Vliet, J. Nicole; Belenkov, Sasha; Essers, Jeroen

    2016-01-01

    The use of Micro-Computed Tomography (MicroCT) for in vivo studies of small animals as models of human disease has risen tremendously due to the fact that MicroCT provides quantitative high-resolution three-dimensional (3D) anatomical data non-destructively and longitudinally. Most importantly, with the development of a novel preclinical iodinated contrast agent called eXIA160, functional and metabolic assessment of the heart became possible. However, prior to the advent of commercial MicroCT scanners equipped with X-ray flat-panel detector technology and easy-to-use cardio-respiratory gating, preclinical studies of cardiovascular disease (CVD) in small animals required a MicroCT technologist with advanced skills, and thus were impractical for widespread implementation. The goal of this work is to provide a practical guide to the use of the high-speed Quantum FX MicroCT system for comprehensive determination of myocardial global and regional function along with assessment of myocardial perfusion, metabolism and viability in healthy mice and in a cardiac ischemia mouse model induced by permanent occlusion of the left anterior descending coronary artery (LAD). PMID:26967592

  8. In Vivo Quantitative Assessment of Myocardial Structure, Function, Perfusion and Viability Using Cardiac Micro-computed Tomography.

    PubMed

    van Deel, Elza; Ridwan, Yanto; van Vliet, J Nicole; Belenkov, Sasha; Essers, Jeroen

    2016-01-01

    The use of Micro-Computed Tomography (MicroCT) for in vivo studies of small animals as models of human disease has risen tremendously due to the fact that MicroCT provides quantitative high-resolution three-dimensional (3D) anatomical data non-destructively and longitudinally. Most importantly, with the development of a novel preclinical iodinated contrast agent called eXIA160, functional and metabolic assessment of the heart became possible. However, prior to the advent of commercial MicroCT scanners equipped with X-ray flat-panel detector technology and easy-to-use cardio-respiratory gating, preclinical studies of cardiovascular disease (CVD) in small animals required a MicroCT technologist with advanced skills, and thus were impractical for widespread implementation. The goal of this work is to provide a practical guide to the use of the high-speed Quantum FX MicroCT system for comprehensive determination of myocardial global and regional function along with assessment of myocardial perfusion, metabolism and viability in healthy mice and in a cardiac ischemia mouse model induced by permanent occlusion of the left anterior descending coronary artery (LAD). PMID:26967592

  9. Low-dose exposure of silica nanoparticles induces cardiac dysfunction via neutrophil-mediated inflammation and cardiac contraction in zebrafish embryos.

    PubMed

    Duan, Junchao; Yu, Yang; Li, Yang; Li, Yanbo; Liu, Hongcui; Jing, Li; Yang, Man; Wang, Ji; Li, Chunqi; Sun, Zhiwei

    2016-06-01

    The toxicity mechanism of nanoparticles on vertebrate cardiovascular system is still unclear, especially on the low-level exposure. This study was to explore the toxic effect and mechanisms of low-dose exposure of silica nanoparticles (SiNPs) on cardiac function in zebrafish embryos via the intravenous microinjection. The dosage of SiNPs was based on the no observed adverse effect level (NOAEL) of malformation assessment in zebrafish embryos. The mainly cardiac toxicity phenotypes induced by SiNPs were pericardial edema and bradycardia but had no effect on atrioventricular block. Using o-Dianisidine for erythrocyte staining, the cardiac output of zebrafish embryos was decreased in a dose-dependent manner. Microarray analysis and bioinformatics analysis were performed to screen the differential expression genes and possible pathway involved in cardiac function. SiNPs induced whole-embryo oxidative stress and neutrophil-mediated cardiac inflammation in Tg(mpo:GFP) zebrafish. Inflammatory cells were observed in atrium of SiNPs-treated zebrafish heart by histopathological examination. In addition, the expression of TNNT2 protein, a cardiac contraction marker in heart tissue had been down-regulated compared to control group using immunohistochemistry. Confirmed by qRT-PCR and western blot assays, results showed that SiNPs inhibited the calcium signaling pathway and cardiac muscle contraction via the down-regulated of related genes, such as ATPase-related genes (atp2a1l, atp1b2b, atp1a3b), calcium channel-related genes (cacna1ab, cacna1da) and the regulatory gene tnnc1a for cardiac troponin C. Moreover, the protein level of TNNT2 was decreased in a dose-dependent manner. For the first time, our results demonstrated that SiNPs induced cardiac dysfunction via the neutrophil-mediated cardiac inflammation and cardiac contraction in zebrafish embryos. PMID:26551753

  10. Methods for reducing biases and errors in regional photochemical model outputs for use in emission reduction and exposure assessments

    NASA Astrophysics Data System (ADS)

    Porter, P. Steven; Rao, S. Trivikrama; Hogrefe, Christian; Gego, Edith; Mathur, Rohit

    2015-07-01

    In the United States, regional-scale photochemical models are being used to design emission control strategies needed to meet the relevant National Ambient Air Quality Standards (NAAQS) within the framework of the attainment demonstration process. Previous studies have shown that the current generation of regional photochemical models can have large biases and errors in simulating absolute levels of pollutant concentrations. Studies have also revealed that regional air quality models were not always accurately reproducing even the relative changes in ozone air quality stemming from changes in emissions. This paper introduces four approaches to adjust for model bias and errors in order to provide greater confidence for their use in estimating future concentrations as well as using modeled pollutant concentrations in exposure assessments. The four methods considered here are a mean and variance (MV) adjustment, temporal component decomposition (TC) adjustment of modeled concentrations, and two variants of cumulative distribution function (CDF) mapping. These methods were compared against each other as well as against unadjusted model concentrations and a version of the relative response approach based on unadjusted model predictions. The analysis uses ozone concentrations simulated by the Community Multiscale Air Quality (CMAQ) model for the northeastern United States domain for the years 1996-2005. Ensuring that base case conditions are adequately represented through the combined use of observations and model simulations is shown to result in improved estimates of future air quality under changing emissions and meteorological conditions.

  11. Magnetic resonance-compatible model of isolated working heart from large animal for multimodal assessment of cardiac function, electrophysiology, and metabolism.

    PubMed

    Vaillant, Fanny; Magat, Julie; Bour, Pierre; Naulin, Jérôme; Benoist, David; Loyer, Virginie; Vieillot, Delphine; Labrousse, Louis; Ritter, Philippe; Bernus, Olivier; Dos Santos, Pierre; Quesson, Bruno

    2016-05-15

    To provide a model close to the human heart, and to study intrinsic cardiac function at the same time as electromechanical coupling, we developed a magnetic resonance (MR)-compatible setup of isolated working perfused pig hearts. Hearts from pigs (40 kg, n = 20) and sheep (n = 1) were blood perfused ex vivo in the working mode with and without loaded right ventricle (RV), for 80 min. Cardiac function was assessed by measuring left intraventricular pressure and left ventricular (LV) ejection fraction (LVEF), aortic and mitral valve dynamics, and native T1 mapping with MR imaging (1.5 Tesla). Potential myocardial alterations were assessed at the end of ex vivo perfusion from late-Gadolinium enhancement T1 mapping. The ex vivo cardiac function was stable across the 80 min of perfusion. Aortic flow and LV-dP/dtmin were significantly higher (P < 0.05) in hearts perfused with loaded RV, without differences for heart rate, maximal and minimal LV pressure, LV-dP/dtmax, LVEF, and kinetics of aortic and mitral valves. T1 mapping analysis showed a spatially homogeneous distribution over the LV. Simultaneous recording of hemodynamics, LVEF, and local cardiac electrophysiological signals were then successfully performed at baseline and during electrical pacing protocols without inducing alteration of MR images. Finally, (31)P nuclear MR spectroscopy (9.4 T) was also performed in two pig hearts, showing phosphocreatine-to-ATP ratio in accordance with data previously reported in vivo. We demonstrate the feasibility to perfuse isolated pig hearts in the working mode, inside an MR environment, allowing simultaneous assessment of cardiac structure, mechanics, and electrophysiology, illustrating examples of potential applications. PMID:26968545

  12. 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 71.48.5 years and a mean APACHE II score of 37.07.6 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 scores (p=0.04). A MAP <65 mmHg was the only hemodynamic parameter significantly predicting the primary endpoint (OR: 4.1, CI: 1.1 - 14.8, p=0.008), whereas the remaining hemodynamic variables CVP, ScvO2, Hematocrit, Troponin I and left ventricular ejection fraction (LVEF) seemed to have no influence on survival. Besides, non-survivors had a significantly higher age (74.19.0 vs. 68.46.9, p=0.01). If hypotension coincided with an age ?72 years, the 28-day mortality rate escalated to 88%. Conclusions: In our study, we identified a risk group with an exceedingly high mortality rate: the patients with an age ?72 years and presenting with hypotension (MAP <65 mmHg). These data can be easily obtained at the time of the very first patient contact. As a result, an aggressive and a more effective treatment can be initiated within the first minutes of the primary care, possibly reducing organ failure and short-term mortality in this risk group. PMID:26392804

  13. Undersampled Cine 3D tagging for rapid assessment of cardiac motion

    PubMed Central

    2012-01-01

    Background CMR allows investigating cardiac contraction, rotation and torsion non-invasively by the use of tagging sequences. Three-dimensional tagging has been proposed to cover the whole-heart but data acquisition requires three consecutive breath holds and hence demands considerable patient cooperation. In this study we have implemented and studied k-t undersampled cine 3D tagging in conjunction with k-t PCA reconstruction to potentially permit for single breath-hold acquisitions. Methods The performance of undersampled cine 3D tagging was investigated using computer simulations and in-vivo measurements in 8 healthy subjects and 5 patients with myocardial infarction. Fully sampled data was obtained and compared to retrospectively and prospectively undersampled acquisitions. Fully sampled data was acquired in three consecutive breath holds. Prospectively undersampled data was obtained within a single breath hold. Based on harmonic phase (HARP) analysis, circumferential shortening, rotation and torsion were compared between fully sampled and undersampled data using Bland-Altman and linear regression analysis. Results In computer simulations, the error for circumferential shortening was 2.8 ± 2.3% and 2.7 ± 2.1% for undersampling rates of R = 3 and 4 respectively. Errors in ventricular rotation were 2.5 ± 1.9% and 3.0 ± 2.2% for R = 3 and 4. Comparison of results from fully sampled in-vivo data acquired with prospectively undersampled acquisitions showed a mean difference in circumferential shortening of −0.14 ± 5.18% and 0.71 ± 6.16% for R = 3 and 4. The mean differences in rotation were 0.44 ± 1.8° and 0.73 ± 1.67° for R = 3 and 4, respectively. In patients peak, circumferential shortening was significantly reduced (p < 0.002 for all patients) in regions with late gadolinium enhancement. Conclusion Undersampled cine 3D tagging enables significant reduction in scan time of whole-heart tagging and facilitates quantification of shortening, rotation and torsion of the left ventricle without adding significant errors compared to previous 3D tagging approaches. PMID:22935509

  14. Bibliometric Assessment of European and Sub-Saharan African Research Output on Poverty-Related and Neglected Infectious Diseases from 2003 to 2011

    PubMed Central

    Gurney, Karen A.; Mgone, Charles S.

    2015-01-01

    Background The European & Developing Countries Clinical Trials Partnership (EDCTP) is a partnership of European and sub-Saharan African countries that aims to accelerate the development of medical interventions against poverty-related diseases (PRDs). A bibliometric analysis was conducted to 1) measure research output from European and African researchers on PRDs, 2) describe collaboration patterns, and 3) assess the citation impact of clinical research funded by EDCTP. Methodology/Principal Findings Disease-specific research publications were identified in Thomson Reuters Web of Science using search terms in titles, abstracts and keywords. Publication data, including citation counts, were extracted for 2003–2011. Analyses including output, share of global papers, normalised citation impact (NCI), and geographical distribution are presented. Data are presented as five-year moving averages. European EDCTP member countries accounted for ~33% of global research output in PRDs and sub-Saharan African countries for ~10% (2007–2011). Both regions contributed more to the global research output in malaria (43.4% and 22.2%, respectively). The overall number of PRD papers from sub-Saharan Africa increased markedly (>47%) since 2003, particularly for HIV/AIDS (102%) and tuberculosis (TB) (81%), and principally involving Southern and East Africa. For 2007–2011, European and sub-Saharan African research collaboration on PRDs was highly cited compared with the world average (NCI in brackets): HIV/AIDS 1.62 (NCI: 1.16), TB 2.11 (NCI: 1.06), malaria 1.81 (NCI: 1.22), and neglected infectious diseases 1.34 (NCI: 0.97). The NCI of EDCTP-funded papers for 2003–2011 was exceptionally high for HIV/AIDS (3.24), TB (4.08) and HIV/TB co-infection (5.10) compared with global research benchmarks (1.14, 1.05 and 1.35, respectively). Conclusions The volume and citation impact of papers from sub-Saharan Africa has increased since 2003, as has collaborative research between Europe and sub-Saharan Africa. >90% of publications from EDCTP-funded research were published in high-impact journals and are highly cited. These findings corroborate the benefit of collaborative research on PRDs. PMID:26262756

  15. Relationship between adductor pollicis muscle thickness and subjective global assessment in a cardiac intensive care unit

    PubMed Central

    Karst, Fernanda Pickrodt; Vieira, Renata Monteiro; Barbiero, Sandra

    2015-01-01

    Objective To verify the relationship between the adductor pollicis muscle thickness test and the subjective global assessment and to correlate it with other anthropometric methods. Methods This observational cross-sectional study was conducted in the intensive care unit of a cardiology hospital in the state of Rio Grande do Sul, Brazil. The hospitalized patients underwent subjective global assessment and adductor pollicis muscle thickness tests on both hands, along with measurement of the right calf circumference. Laboratory parameters, length of stay, vital signs and electronic medical record data and tests were all collected. Results The study population included 83 patients, of whom 62% were men. The average age was 68.6 ± 12.5 years. The most common reason for hospitalization was acute myocardial infarction (34.9%), and the most common pathology was systolic blood pressure (63.9%), followed by diabetes mellitus (28.9%). According to subjective global assessment classifications, 62.7% of patients presented no nutritional risk, 20.5% were moderately malnourished and 16.9% were severely malnourished. Women had a higher nutritional risk, according to both the subjective global assessment and the adductor pollicis muscle thickness test, the cutoff for which was < 6.5mm (54.8%; p = 0.001). The pathology presenting the greatest nutritional risk was congestive heart failure (p = 0.001). Evaluation of the receiver operating characteristic (ROC) curve between adductor pollicis muscle thickness and subjective global assessment showed the accuracy of the former, with an area of 0.822. Conclusion Adductor pollicis muscle thickness proved to be a good method for evaluating nutritional risk. PMID:26761475

  16. Bleeding risk assessment in patients undergoing elective cardiac surgery using ROTEM(®) platelet and Multiplate(®) impedance aggregometry.

    PubMed

    Petricevic, M; Konosic, S; Biocina, B; Dirkmann, D; White, A; Mihaljevic, M Z; Ivancan, V; Konosic, L; Svetina, L; Görlinger, K

    2016-06-01

    Impaired platelet function is a major risk factor for peri-operative bleeding and transfusion. This prospective, observational study enrolled 101 consecutive patients undergoing elective cardiac surgery with cardiopulmonary bypass. Platelet function was assessed by two whole blood impedance aggregometers (ROTEM(®) platelet and Multiplate(®) ), using three different activators (arachidonic acid, adenosine diphosphate and thrombin receptor-activating peptide-6), at three peri-operative time points (before anaesthesia, after aortic declamping and 5-10 min after protamine administration). Platelet function was impaired over the time-course in all assays. Results after protamine administration demonstrated the best correlation with postoperative chest tube drainage. Patients with a chest tube drainage exceeding the 75th percentile of the entire study population, during the first 24 postoperative hours, were characterised to have excessive bleeding. Both devices provided similar predictability for postoperative chest tube drainage and red blood cell transfusion requirements. The latter was associated with the degree of platelet inhibition and the number of pathways inhibited determined respective cut-off values. PMID:26763378

  17. China Patient-centered Evaluative Assessment of Cardiac Events Prospective Study of Acute Myocardial Infarction: Study Design

    PubMed Central

    Li, Jing; Dreyer, Rachel P; Li, Xi; Du, Xue; Downing, Nicholas S; Li, Li; Zhang, Hai-Bo; Feng, Fang; Guan, Wen-Chi; Xu, Xiao; Li, Shu-Xia; Lin, Zhen-Qiu; Masoudi, Frederick A; Spertus, John A; Krumholz, Harlan M; Jiang, Li-Xin

    2016-01-01

    Background: Despite the rapid growth in the incidence of acute myocardial infarction (AMI) in China, there is limited information about patients’ experiences after AMI hospitalization, especially on long-term adverse events and patient-reported outcomes (PROs). Methods: The China Patient-centered Evaluative Assessment of Cardiac Events (PEACE)-Prospective AMI Study will enroll 4000 consecutive AMI patients from 53 diverse hospitals across China and follow them longitudinally for 12 months to document their treatment, recovery, and outcomes. Details of patients’ medical history, treatment, and in-hospital outcomes are abstracted from medical charts. Comprehensive baseline interviews are being conducted to characterize patient demographics, risk factors, presentation, and healthcare utilization. As part of these interviews, validated instruments are administered to measure PROs, including quality of life, symptoms, mood, cognition, and sexual activity. Follow-up interviews, measuring PROs, medication adherence, risk factor control, and collecting hospitalization events are conducted at 1, 6, and 12 months after discharge. Supporting documents for potential outcomes are collected for adjudication by clinicians at the National Coordinating Center. Blood and urine samples are also obtained at baseline, 1- and 12-month follow-up. In addition, we are conducting a survey of participating hospitals to characterize their organizational characteristics. Conclusion: The China PEACE-Prospective AMI study will be uniquely positioned to generate new information regarding patient's experiences and outcomes after AMI in China and serve as a foundation for quality improvement activities. PMID:26712436

  18. [Multidisciplinary team in cardiac rehabilitation and secondary prevention, from the assessment to the education: an educational project].

    PubMed

    Da Vico, Letizia; Ciompi, Maddalena; Schinin, Francesca; Sogaro, Elena; Mannelli, Weruska; Cortini, Sandro

    2014-03-01

    The authors explain the training project: "Multidisciplinarity in cardiac rehabilitation and secondary prevention: from the evaluation to the therapeutic education", the rationale and purpose of a pathway for patients with ischemic heart disease treated in the acute phase with both medical and surgical means, and then placed in a rehabilitation program. The training project was transformed into a learning event for the Region of Sicily and later for the Region of Tuscany that has adopted it, encouraging the spread over the entire region. It highlights the role of the team, which focuses on the patient, converging on it multidisciplinary expertise whose goal is the reintegration of the subjects in their life-context, with appropriate evaluation, treatment and changes in lifestyle. From the valuations and declining the specific interventions to each job profile according to the principle of synergy obtained by multi-professional integration. All phases of the training project (assessment, intervention, evaluation) are addressed by each of the professionals (nurse, dietitian, physiotherapist, psychologist) that under the responsibility of the cardiologist realize, within the welfare, a concrete process of therapeutic education from which no one can ignore the "vision" of a global care of the patient. PMID:25481939

  19. [Multidisciplinary team in cardiac rehabilitation and secondary prevention, from the assessment to the education: an educational project].

    PubMed

    Da Vico, Letizia; Ciompi, Maddalena; Schinin, Francesca; Sogaro, Elena; Mannelli, Weruska; Cortini, Sandro

    2014-03-01

    The authors explain the training project: "Multidisciplinarity in cardiac rehabilitation and secondary prevention: from the evaluation to the therapeutic education", the rationale and purpose of a pathway for patients with ischemic heart disease treated in the acute phase with both medical and surgical means, and then placed in a rehabilitation program. The training project was transformed into a learning event for the Region of Sicily and later for the Region of Tuscany that has adopted it, encouraging the spread over the entire region. It highlights the role of the team, which focuses on the patient, converging on it multidisciplinary expertise whose goal is the reintegration of the subjects in their life-context, with appropriate evaluation, treatment and changes in lifestyle. From the valuations and declining the specific interventions to each job profile according to the principle of synergy obtained by multi-professional integration. All phases of the training project (assessment, intervention, evaluation) are addressed by each of the professionals (nurse, dietitian, physiotherapist, psychologist) that under the responsibility of the cardiologist realize, within the welfare, a concrete process of therapeutic education from which no one can ignore the "vision" of a global care of the patient. PMID:25508791

  20. Assessment of the intrapulmonary ventilation-perfusion distribution after the Fontan procedure for complex cardiac anomalies: Relation to pulmonary hemodynamics

    SciTech Connect

    Matsushita, T.; Matsuda, H.; Ogawa, M.; Ohno, K.; Sano, T.; Nakano, S.; Shimazaki, Y.; Nakahara, K.; Arisawa, J.; Kozuka, T. )

    1990-03-15

    In 12 patients who underwent the Fontan procedure for complex cardiac anomalies, lung scanning with xenon-133 was performed to assess the intrapulmonary ventilation-perfusion distribution, and comparison was made with a control group. All data were then analyzed in relation to either pre- or postoperative pulmonary hemodynamic data. In ventilation scans, the intrapulmonary distribution in the right lung was almost normal. In perfusion scans, an abnormal increased upper to lower lobe perfusion ratio greater than the normal value found in the control group was noted in seven patients (58.3%). There was a significant correlation (p less than 0.02) between the upper to lower lobe perfusion ratio and postoperative pulmonary vascular resistance. Furthermore, this perfusion ratio correlated inversely with the preoperative (p less than 0.005) and postoperative (p less than 0.02) right pulmonary artery area index, defined as the ratio of cross-sectional area to the normal value. Of five patients with less than 90% arterial oxygen saturation, four showed an abnormal distribution of pulmonary blood flow greater than the normal perfusion ratio. No patient had evidence of a pulmonary arteriovenous fistula by the echocardiographic contrast study. These results suggest that abnormal distribution of pulmonary blood flow to the upper lung segment may develop in patients after the Fontan procedure, and that insufficient size of the pulmonary artery before operation and the consequent postoperative elevation of pulmonary vascular resistance may be responsible for this perfusion abnormality.

  1. Paving the Route to Plasma miR-208a-3p as an Acute Cardiac Injury Biomarker: Preclinical Rat Data Supports Its Use in Drug Safety Assessment.

    PubMed

    Glineur, Stéphanie F; De Ron, Pierrette; Hanon, Etienne; Valentin, Jean-Pierre; Dremier, Sarah; Nogueira da Costa, André

    2016-01-01

    Drug-induced cardiac injury (DICI) detection remains a major safety issue in drug development. While circulating microRNAs (miRs) have emerged as promising translational biomarkers, novel early detection biomarkers of cardiotoxicity are needed. This work aims at evaluating whether a panel of putative cardiac injury plasma miRs could serve as early DICI biomarkers in a 4-day rat preclinical model. Out of a panel of 68 selected targets, we identified plasma miR-208a-3p as being significantly upregulated after single administration with either isoproterenol (ISO) or allylamine (AAM). This provides the first evidence of miR-208a-3p detection after AAM administration. Moreover, similarly to cardiac troponins (cTn), plasma miR-208a-3p expression profile appears to be compound-specific with most significant early changes occurring in ISO-treated rats. Overall, miR-208a-3p performance in detecting the severity of myocardial injury, as well as the magnitude of miR-208a-3p increase after ISO or AAM administration, were comparable to that of cTn. Our results highlight the importance of assessing the whole time-dependent profiles of miR expression. Hence, time course evaluation revealed plasma miR candidates whose expression was not stable across the duration of the study in the vehicle group, restricting their utility as cardiac injury-specific biomarkers. In light of these findings, miR-208a-3p has a potential to complement the existing biomarkers of cardiac injury specifically in the context of evaluating toxicity in a time-dependant manner. Assessment of miR-208a-3p in other DICI settings would strengthen its robustness as an early detection biomarker leading to a warranted extensive and rigorous validation. PMID:26454886

  2. Effect of a Cognitive Aid on Adherence to Perioperative Assessment and Management Guidelines for the Cardiac Evaluation of Non-Cardiac Surgical Patients

    PubMed Central

    Bridges, Kathryn H; Stiegler, Marjorie P; Schell, Randall M; DiLorenzo, Amy N; Ehrenfeld, Jesse M; Nietert, Paul J; McEvoy, Matthew D

    2014-01-01

    BACKGROUND The 2007 American College of Cardiologists/American Heart Association Guidelines on Perioperative Cardiac Evaluation and Care for Noncardiac Surgery is the standard for perioperative cardiac evaluation. Recent work has shown residents and anesthesiologists do not apply these guidelines when tested. This research hypothesized that a decision support tool would improve adherence to this consensus guideline. METHODS Anesthesiology residents at 4 training programs participated in an unblinded prospective randomized cross-over trial in which they completed two tests covering clinical scenarios. One quiz was completed from memory and one with the aid of an electronic decision support tool. Performance was evaluated by overall score (% correct), number of incorrect answers with possibly increased cost or risk of care, and the amount of time required to complete the quizzes both with and without the cognitive aid. The primary outcome was the proportion of correct responses attributable to the use of the decision support tool. RESULTS All anesthesiology residents at four institutions were recruited and 111 residents participated. Use of the decision support tool resulted in a 25% improvement in adherence to guidelines compared to memory alone (p<0.0001), and participants made 77% fewer incorrect responses that would have resulted in increased costs. Use of the tool was associated with a 3.4-minute increase in time to complete the test (p<0.001). CONCLUSIONS Use of an electronic decision support tool significantly improved adherence to the guidelines as compared to memory alone. The decision support tool also prevented inappropriate management steps possibly associated with increased healthcare costs. PMID:24705442

  3. Assessing Late Cardiopulmonary Function in Patients with Repaired Tetralogy of Fallot Using Exercise Cardiopulmonary Function Test and Cardiac Magnetic Resonance

    PubMed Central

    Yang, Ming-Chun; Chen, Chun-An; Chiu, Hsin-Hui; Chen, Ssu-Yuan; Wang, Jou-Kou; Lin, Ming-Tai; Chiu, Shuenn-Nan; Lu, Chun-Wei; Huang, Shu-Chien; Wu, Mei-Hwan

    2015-01-01

    Background Patients with repaired tetralogy of Fallot (TOF) usually experience progressive right ventricle (RV) dysfunction due to pulmonary regurgitation (PR). This could further worsen the cardiopulmonary function. This study aimed to compare the changes in patient exercise cardiopulmonary test and cardiac magnetic resonance imaging, and consider the implication of these changes. Methods Our study examined repaired TOF patients who underwent cardiopulmonary exercise test (CPET) to obtain maximal (peak oxygen consumption, peak VO2) and submaximal parameters (oxygen uptake efficiency plateau, oxygen uptake efficiency plateau (OUEP), and ratio of minute ventilation to carbon dioxide production, VE/VCO2 slope). Additionally, the hemodynamic status was assessed by using cardiac magnetic resonance. Criteria for exclusion included TOF patients with pulmonary atresia, atrioventricular septal defect, or absence of pulmonary valve syndrome. Results We enrolled 158 patients whose mean age at repair was 7.8 ± 9.1 years (range 0.1-49.2 years) and the mean patient age at CPET was 29.5 ± 12.2 years (range 7.0-57.0 years). Severe PR (PR fraction ≥ 40%) in 53 patients, moderate in 55, and mild (PR fraction < 20%) in 50 patients were noted. The mean RV end-diastolic volume index (RVEDVi) was 113 ± 35 ml/m2, with 7 patients observed to have a RVEDVi > 163 ml/m2. The mean left ventricular ejection fraction (LVEF) was 63 ± 8%, left ventricular end-diastolic volume index (LVEDVi) was 65 ± 12 ml/m2, and LVESVi was 25 ± 14 ml/m2. CPET revealed significantly decreased peak VO2 (68.5 ± 14.4% of predicted), and fair OUEP (90.3 ± 14.1% of predicted) and VE/VCO2 slope (27.1 ± 5.3). PR fraction and age at repair were negatively correlated with maximal and submaximal exercise indicators (peak VO2 and OUEP). Left ventricular (LV) function and size were positively correlated with peak VO2 and OUEP. Conclusions The results of CPET showed that patients with repaired TOF had a low maximal exercise capacity (peak VO2), but a fair submaximal exercise capacity (OUEP and VE/VCO2 slope), suggesting limited exercise capability in high intensity circumstances. PR, LV function and age at total repair were the most important determinants of CPET performance. PMID:27122911

  4. Naturally occurring cardiac glycosides.

    PubMed

    Radford, D J; Gillies, A D; Hinds, J A; Duffy, P

    1986-05-12

    Cardiac glycoside poisoning from the ingestion of plants, particularly of oleanders, occurs with reasonable frequency in tropical and subtropical areas. We have assessed a variety of plant specimens for their cardiac glycoside content by means of radioimmunoassays with antibodies that differ in their specificity for cardiac glycosides. Significant amounts of immunoreactive cardiac glycoside were found to be present in the ornamental shrubs: yellow oleander (Thevetia peruviana); oleander (Nerium oleander); wintersweet (Carissa spectabilis); bushman's poison (Carissa acokanthera); sea-mango (Cerbera manghas); and frangipani (Plumeria rubra); and in the milkweeds: redheaded cotton-bush (Asclepias curassavica); balloon cotton (Asclepias fruiticosa); king's crown (Calotropis procera); and rubber vine (Cryptostegia grandifolia). The venom gland of the cane toad (Bufo marinus) also contained large quantities of cardiac glycosides. The competitive immunoassay method permits the rapid screening of specimens that are suspected to contain cardiac glycosides. Awareness of the existence of these plant and animal toxins and their dangers allows them to be avoided and poisoning prevented. The method is also useful for the confirmation of the presence of cardiac glycosides in serum in cases of poisoning. PMID:3086679

  5. Assessment of cerebellar pulsation in dogs with and without Chiari-like malformation and syringomyelia using cardiac-gated cine magnetic resonance imaging.

    PubMed

    Driver, C J; Watts, V; Bunck, A C; Van Ham, L M; Volk, H A

    2013-10-01

    Canine Chiari-like malformation (CM) is characterised by herniation of part of the cerebellum through the foramen magnum. In humans with Chiari type I malformation (CM-I), abnormal pulsation of the cerebellum during the cardiac cycle has been documented and is pivotal to theories for the pathogenesis of syringomyelia (SM). In this retrospective study, cardiac-gated cine balanced fast field echo (bFEE) magnetic resonance imaging (MRI) was used to assess pulsation of the brain in dogs and to objectively measure the degree of cerebellar pulsation with the neck in a flexed position. Overall, 17 Cavalier King Charles Spaniels (CKCS) with CM, including eight with SM and nine without SM, were compared with six small breed control dogs. Linear regions of interest were generated for the length of cerebellar herniation from each phase of the cardiac cycle and the degree of cerebellar pulsation was subsequently calculated. Age, bodyweight and angle of neck flexion were also compared. CKCS with CM and SM had significantly greater pulsation of the cerebellum than control dogs (P=0.003) and CKCS with CM only (P=0.031). There was no significant difference in age, bodyweight and angle of neck flexion between the three groups. Cardiac-gated cine bFEE MRI permitted the dynamic visualisation of cerebellar pulsation in dogs. These findings support the current theories regarding the pathogenesis of SM secondary to CM and further highlight the similarities between canine CM and human CM-I. PMID:23770398

  6. Introduction--databases and the assessment of complications associated with the treatment of patients with congenital cardiac disease.

    PubMed

    Jacobs, Jeffrey P

    2008-12-01

    The Multi-Societal Database Committee for Pediatric and Congenital Heart Disease was established in 2005 with the goal of providing the infrastructure, spanning geographical and subspecialty boundaries, for collaboration between health care professionals interested in the analysis of outcomes of treatments provided to patients with congenital cardiac disease, with the ultimate aim of improvement in the quality of care provided to these patients. The purpose of these collaborative efforts is to promote the highest quality comprehensive cardiac care to all patients with congenital heart disease, from the fetus to the adult, regardless of the patient's economic means, with an emphasis on excellence in teaching, research and community service. This manuscript provides the Introduction to the 2008 Supplement to Cardiology in the Young titled: "Databases and The Assessment of Complications associated with the Treatment of Patients with Congenital Cardiac Disease". This Supplement was prepared by The Multi-Societal Database Committee for Pediatric and Congenital Heart Disease. The Multi-Societal Database Committee for Pediatric and Congenital Heart Disease offers the following definition of the term "Complication": "A complication is an event or occurrence that is associated with a disease or a healthcare intervention, is a departure from the desired course of events, and may cause, or be associated with, suboptimal outcome. A complication does not necessarily represent a breech in the standard of care that constitutes medical negligence or medical malpractice. An operative or procedural complication is any complication, regardless of cause, occurring (1) within 30 days after surgery or intervention in or out of the hospital, or (2) after 30 days during the same hospitalization subsequent to the operation or intervention. Operative and procedural complications include both intraoperative/intraprocedural complications and postoperative/postprocedural complications in this time interval." The Multi-Societal Database Committee for Pediatric and Congenital Heart Disease offers the following definition of the term "Adverse Event": "An adverse event is a complication that is associated with a healthcare intervention and is associated with suboptimal outcome. Adverse events represent a subset of complications. Not all medical errors result in an adverse event; the administration of an incorrect dose of a medication is a medical error, but it does not always result in an adverse event. Similarly, not all adverse events are the result of medical error. A child may develop pneumonia after an atrial septal defect repair despite intra- and peri-operative management that is free of error. Complications of the underlying disease state, which are not related to a medical intervention, are not adverse events. For example, a patient who presents for medical care with metastatic lung cancer has already developed a complication (Metastatic spread) of the primary lung cancer without any healthcare intervention. Furthermore, complications not associated with suboptimal outcome or harm are not adverse events and are known as no harm events. The patient who receives an incorrect dose of a medication without harm has experienced a no harm event, but not an adverse event." Based on the above definitions, it is apparent that The Multi-Societal Database Committee for Pediatric and Congenital Heart Disease has taken an inclusive approach to defining the universe of complications. Complications may or may not be associated with healthcare intervention and may or may not be associated with suboptimal outcome. Meanwhile, adverse events must be associated with healthcare intervention and must be associated with suboptimal outcome. PMID:19063774

  7. Assessment of the Turkish Version of the King's Stool Chart for Evaluating Stool Output and Diarrhea Among Patients Receiving Enteral Nutrition.

    PubMed

    Sucu Dag, Gülten; Dicle, Aklime; Saka, Osman; Whelan, Kevin

    2015-01-01

    The purpose of this study was to evaluate the reliability and validity of the Turkish version of the King's Stool Chart (KSC-Tr) in patients receiving enteral nutrition. In total, 212 stool samples taken from 25 patients receiving enteral nutrition during 393 sick days in two intensive care units were assessed using the KSC-Tr. Overall, 110 of 212 stools (51.9%) were characterized as liquid and 111 of 212 stools (52.4%) were characterized as less than 100 g. The daily stool score of patients receiving antibiotics, a risk factor for diarrhea, was higher (mean = 13.6; SD = 10.1) than that of patients not receiving antibiotics (mean = 9.3; SD = 5.0) (p = .001). Diarrhea occurred on more days when patients received antibiotics (62/329; 18.8%) than on days when they did not (3/64; 4.7%) (p = .005). Interobserver agreement of two independent nurses' assessments on 44 stool samples was examined and was good for both stool consistency (κ = 0.76) and stool weight (κ = 0.75). In the intensive care unit, the KSC-Tr can be used as a valid and reliable tool for monitoring diarrhea and stool output in patients receiving enteral nutrition. PMID:25946479

  8. Monte Carlo simulations to assess differentiation between defects in cardiac SPECT

    NASA Astrophysics Data System (ADS)

    Chrysanthou-Baustert, I.; Parpottas, Y.; Demetriadou, O.; Christofides, S.; Yiannakkaras, Ch; Kaolis, D.; Wasilewska-Radwanska, M.

    2011-09-01

    Differentiating between various types of lesions in nuclear cardiology is a challenge. This work assesses the level of differentiation achievable between various low contrast lesions, as encountered in nuclear cardiology. The parameters investigated are defect extend, defect thickness and perfusion reduction of the defect. The images have been obtained through Monte Carlo Simulations with the program SIMIND. Results show that acceptable size resolution is obtained for defects with an extend over 25×25mm. When thickness and perfusion reduction are both unknown, the imaging results are confounding. In this work, thickness and perfusion reduction cannot be differentiated. If one of the variables is known (thickness or perfusion reduction), imaging results can differentiate between the other unknown variable.

  9. Remote detection of mental workload changes using cardiac parameters assessed with a low-cost webcam.

    PubMed

    Bousefsaf, Frdric; Maaoui, Choubeila; Pruski, Alain

    2014-10-01

    We introduce a new framework for detecting mental workload changes using video frames obtained from a low-cost webcam. Image processing in addition to a continuous wavelet transform filtering method were developed and applied to remove major artifacts and trends on raw webcam photoplethysmographic signals. The measurements are performed on human faces. To induce stress, we have employed a computerized and interactive Stroop color word test on a set composed by twelve participants. The electrodermal activity of the participants was recorded and compared to the mental workload curve assessed by merging two parameters derived from the pulse rate variability and photoplethysmographic amplitude fluctuations, which reflect peripheral vasoconstriction changes. The results exhibit strong correlation between the two measurement techniques. This study offers further support for the applicability of mental workload detection by remote and low-cost means, providing an alternative to conventional contact techniques. PMID:25150821

  10. Cardiac function after surgery for subaortic stenosis: non-invasive assessment of left ventricular performance.

    PubMed Central

    Chan, K Y; Redington, A N; Rigby, M L; Gibson, D G

    1991-01-01

    OBJECTIVE--To examine left ventricular function after surgical resection of subaortic stenosis during childhood. DESIGN--Left ventricular performance was measured non-invasively in all patients who responded to an invitation for formal assessment. SETTING--Outpatient study, tertiary referral centre. PATIENTS--Twenty three (12 male and 11 female) patients (age range 3 to 31 years) of 43 consecutive patients with fixed subaortic stenosis undergoing surgical resection between 1975 and 1989 reattended for formal assessment 16 months to 15 years (median 4 years 4 months) after operation. MAIN OUTCOME MEASURES--Left ventricular dimension, left ventricular wall thickness, left ventricular Doppler inflow velocities, and left ventricular diastolic pressure (measured from apexcardiograms). Results were compared with those in controls individually matched for age and sex. RESULTS--All patients were symptom free. Left ventricular cavity dimensions were normal, as was the mean fractional shortening. Posterior wall thickness tended to be greater in the patients and there was a significant increase in septal thickness. Normalised peak rate of posterior wall thinning was significantly lower in the patients and the isovolumic relaxation time was significantly shorter. Doppler inflow velocity measurements showed that early diastolic mitral flow acceleration time was normal but deceleration time was significantly shorter in the patients. The ratio of mitral flow in early diastole (E) to E plus mitral flow in late diastole (A) was significantly higher in the patients and in two patients there was complete absence of A wave flow despite large A waves on the apexcardiogram. CONCLUSIONS--Systolic function was well preserved in patients after operation for subaortic stenosis. A restrictive pattern of left ventricular filling was common, however, and presumably reflected a response to the chronic pressure load and to surgery in the paediatric heart. Images PMID:1883668

  11. Renal function assessment in child and adolescent heart transplant recipients during routine cardiac catheterization.

    PubMed

    Lin, Kimberly Y; Furth, Susan L; Schwartz, George J; Shaddy, Robert E; Ruebner, Rebecca L

    2014-11-01

    CKD identification after pediatric heart transplantation (PHT) is limited by inaccuracies in estimates of GFR. We hypothesized that GFR can be measured by a modified iohexol clearance protocol in PHT recipients and that the CKiD formula provides a better estimate of GFR than other estimating equations. A cross-sectional study of PHT recipients, ages 2-18 yr, undergoing coronary angiography was undertaken. The angiography dose of iohexol was divided by the area under the curve from three iohexol levels post-infusion to calculate GFR. Agreement between iGFR and multiple estimating equations (eGFR) was assessed. In 31 subjects, median age was 15.0 yr (IQR 7.6, 16.6). Mean iGFR was 93.8 (s.d. 22.5) mL/min/1.73 m(2) ; 16 (52%) had an iGFR <90 mL/min/1.73 m(2) . The full CKiD formula (mean eGFR 88.9, s.d. 14.9) had low bias (-5.0), narrowest 95% limits of agreement (-42.0, 32.1), highest 30% (94%) and 10% (52%) accuracy, and highest correlation coefficient (0.576) relative to iGFR. We describe a novel modified iohexol clearance method to assess GFR after PHT. Over half of the cohort had an iGFR <90, suggesting CKD. The full CKiD formula performs best with respect to bias, accuracy, and correlation. PMID:25112413

  12. Assessment of Liver Fibrosis Using Fast Strain-Encoded (FSENC) MRI Driven by Inherent Cardiac Motion

    PubMed Central

    Harouni, Ahmed A.; Gharib, Ahmed M.; Osman, Nael F.; Morse, Caryn; Heller, Theo; Abd-Elmoniem, Khaled Z.

    2014-01-01

    Purpose An external driver-free MRI method for assessment of liver fibrosis offers a promising non-invasive tool for diagnosis and monitoring of liver disease. Lately, the heart’s intrinsic motion and MR tagging have been utilized for the quantification of liver strain. However, MR tagging requires multiple breath-hold acquisitions and substantial post-processing. This work proposes a fast strain-encoded (FSENC) MRI methodology to measure the peak strain (Sp) in the liver’s left lobe, which is in close proximity and caudal to the heart. Additionally, a new method is introduced to measure heart-induced shear wave velocity (SWV) inside the liver. Methods Phantom and in-vivo experiments (11 healthy subjects, and 11 patients with liver fibrosis) were conducted. Reproducibility experiments were performed in seven healthy subjects. Results Peak liver strain Sp significantly decreased in fibrotic liver compared healthy liver (6.46%±2.27% vs. 12.49%±1.76%, P<0.05). Heart-induced SWV significantly increased in patients compared to healthy subjects (0.15±0.04 m/s vs. 0.63±0.32 m/s, P<0.05). Reproducibility analysis yielded no significant difference in Sp (P=0.47) or SWV (P=0.56). Conclusion Accelerated external driver-free noninvasive assessment of left liver lobe strain and shear wave velocity is feasible using strain-encoded MRI. The two measures significantly separate healthy subjects from patients with fibrotic liver. PMID:25081734

  13. An Assessment of Emergency Department Post-Cardiac Arrest Care Variation in Michigan.

    PubMed

    Kotini-Shah, Pavitra; Camp-Rogers, Teresa R; Swor, Robert A; Sawyer, Kelly N

    2016-03-01

    Implementation of postarrest care by individual physicians and systems has been slow. Deadoption, or discontinuation of therapeutic hypothermia (TH) treatment targets, after recent prospective study results has not been well reported. This study assesses practices in the early stages of postarrest care across emergency departments (EDs) in Michigan. A 27-question Internet-based survey was distributed to EDs in Michigan in September 2013. To assess changes in practice after publication of Nielsen et al., we sent follow-up questions to all original respondents a year later. Observational data and descriptive statistics are reported. From the 142 EDs identified, we excluded critical access hospitals (N = 35), free standing EDs (N = 7), EDs that transfer critical patients to tertiary centers (N = 21), and exclusive children's hospitals (N = 3). Of the remaining 76 hospitals, we received 64 (84.2%) responses. We identified 15 respondents with a protocol to specifically initiate ED TH and transfer patients to a higher level of care. The 49 remaining were mostly teaching institutions (N = 34, 69%) and gave the ED physician the ability to initiate TH (N = 40, 82%). On follow-up 12 months later, we received 33/40 (83%) responses, of which only 5 indicated formal or informal change in TH practice or target temperature. There is substantial variation in the practice of ED postarrest care and initiation of TH across the state of Michigan, but few ED TH protocols were changed in a year's time. The consequences of postarrest treatment variability at the state and ED levels are likely under-recognized as an influence on outcome variation between regions. PMID:26654317

  14. Assessing Cardiac Injury in Mice With Dual Energy-MicroCT, 4D-MicroCT, and MicroSPECT Imaging After Partial Heart Irradiation

    SciTech Connect

    Lee, Chang-Lung; Min, Hooney; Befera, Nicholas; Clark, Darin; Qi, Yi; Das, Shiva; Johnson, G. Allan; Badea, Cristian T.; Kirsch, David G.

    2014-03-01

    Purpose: To develop a mouse model of cardiac injury after partial heart irradiation (PHI) and to test whether dual energy (DE)-microCT and 4-dimensional (4D)-microCT can be used to assess cardiac injury after PHI to complement myocardial perfusion imaging using micro-single photon emission computed tomography (SPECT). Methods and Materials: To study cardiac injury from tangent field irradiation in mice, we used a small-field biological irradiator to deliver a single dose of 12 Gy x-rays to approximately one-third of the left ventricle (LV) of Tie2Cre; p53{sup FL/+} and Tie2Cre; p53{sup FL/−} mice, where 1 or both alleles of p53 are deleted in endothelial cells. Four and 8 weeks after irradiation, mice were injected with gold and iodinated nanoparticle-based contrast agents, and imaged with DE-microCT and 4D-microCT to evaluate myocardial vascular permeability and cardiac function, respectively. Additionally, the same mice were imaged with microSPECT to assess myocardial perfusion. Results: After PHI with tangent fields, DE-microCT scans showed a time-dependent increase in accumulation of gold nanoparticles (AuNp) in the myocardium of Tie2Cre; p53{sup FL/−} mice. In Tie2Cre; p53{sup FL/−} mice, extravasation of AuNp was observed within the irradiated LV, whereas in the myocardium of Tie2Cre; p53{sup FL/+} mice, AuNp were restricted to blood vessels. In addition, data from DE-microCT and microSPECT showed a linear correlation (R{sup 2} = 0.97) between the fraction of the LV that accumulated AuNp and the fraction of LV with a perfusion defect. Furthermore, 4D-microCT scans demonstrated that PHI caused a markedly decreased ejection fraction, and higher end-diastolic and end-systolic volumes, to develop in Tie2Cre; p53{sup FL/−} mice, which were associated with compensatory cardiac hypertrophy of the heart that was not irradiated. Conclusions: Our results show that DE-microCT and 4D-microCT with nanoparticle-based contrast agents are novel imaging approaches complementary to microSPECT for noninvasive assessment of the change in myocardial vascular permeability and cardiac function of mice in whom myocardial injury develops after PHI.

  15. Real-Time Assessment of Cardiac Perfusion, Coronary Angiography, and Acute Intravascular Thrombi Using Dual-Channel Near-Infrared Fluorescence Imaging

    PubMed Central

    Tanaka, Eiichi; Chen, Frederick Y.; Flaumenhaft, Robert; Graham, Gwenda J.; Laurence, Rita G.; Frangioni, John V.

    2009-01-01

    Objectives We have developed an image-guided surgery system based on invisible near-infrared (NIR) fluorescent light. Presently, the only clinically-available NIR fluorophore is indocyanine green (ICG), which fluoresces at ? 800 nm and is used for coronary angiography. Our objective was to determine if methylene blue (MB), already FDA-approved for other indications, has useful NIR fluorescence properties for image-guided cardiac surgery. Methods The optical properties of MB were measured after dissolution in 100% serum. Biodistribution and clearance were quantified in organs and tissues after intravenous bolus injection of 2 mg/kg MB in N = 3 rats. Coronary arteriography and cardiac perfusion were imaged in real-time after intravenous bolus injection of 1 mg/kg MB in N = 5 pigs with coronary obstructions. Coronary angiography and acute thrombi were assessed using 800 nm fluorophores, ICG and IR-786-labeled platelets, respectively. Results The peak absorbance and emission of MB as a NIR fluorophore occur at 667 nm and 686 nm, respectively. After intravenous injection, MB provides highly sensitive coronary angiography. A lipophilic cation, MB is extracted rapidly into tissue, with myocardium displaying unusually high uptake. MB permits real-time visualization and quantitative assessment of myocardial perfusion. Because of absent spectral overlap, use of two independent fluorophores on our imaging system permits simultaneous quantification of perfusion, venous drainage and/or intravascular thrombi. Conclusions MB is an effective NIR fluorophore that provides direct visualization of coronary arteriography and cardiac perfusion. In conjunction with ? 800 nm NIR fluorophores, important functional assessments during cardiac surgery are also possible. PMID:19577070

  16. Update on intravenous dipyridamole cardiac imaging in the assessment of ischemic heart disease

    SciTech Connect

    Younis, L.T.; Chaitman, B.R. )

    1990-01-01

    Intravenous dipyridamole is a relative selective coronary vasodilator which, when combined with thallium-201, provides a useful technique to assess myocardial perfusion. The intravenous dipyridamole is administered as an infusion at a rate of 0.14 mg/kg/min for 4 minutes. In the presence of significant coronary artery disease the increase of coronary blood flow is disproportionate between vessels with and without significant coronary lesions, providing the basis for detecting regional differences in flow using thallium-201. The test can be used alone or combined with low level exercise to increase test sensitivity. The test is safe when performed under medical supervision and when patient selection is done appropriately. Most of the side effects induced by dipyridamole infusion are well tolerated by patients and readily reversed with intravenous aminophylline and sublingual nitroglycerin. The average sensitivity and specificity of the dipyridamole thallium scintigraphy test from the major studies are 76% and 70%, respectively. The test is very useful in providing prognostic information in patients who are unable to exercise. A reversible thallium defect after dipyridamole infusion has been shown to be associated with significant mortality and morbidity in patients with documented or suspected coronary artery disease. The use of intravenous dipyridamole has been extended into other modalities of imaging, including 2-dimensional and Doppler echocardiography, to study functional changes in the left ventricular induced by the infusion of intravenous dipyridamole. 52 references.

  17. Radiation dose assessment in a 320-detector-row CT scanner used in cardiac imaging

    SciTech Connect

    Goma, Carles; Ruiz, Agustin; Jornet, Nuria; Latorre, Artur; Pallerol, Rosa M.; Carrasco, Pablo; Eudaldo, Teresa; Ribas, Montserrat

    2011-03-15

    Purpose: In the present era of cone-beam CT scanners, the use of the standardized CTDI{sub 100} as a surrogate of the idealized CTDI is strongly discouraged and, consequently, so should be the use of the dose-length product (DLP) as an estimate of the total energy imparted to the patient. However, the DLP is still widely used as a reference quantity to normalize the effective dose for a given scan protocol mainly because the CTDI{sub 100} is an easy-to-measure quantity. The aim of this article is therefore to describe a method for radiation dose assessment in large cone-beam single axial scans, which leads to a straightforward estimation of the total energy imparted to the patient. The authors developed a method accessible to all medical physicists and easy to implement in clinical practice in an attempt to update the bridge between CT dosimetry and the estimation of the effective dose. Methods: The authors used commercially available material and a simple mathematical model. The method described herein is based on the dosimetry paradigm introduced by the AAPM Task Group 111. It consists of measuring the dose profiles at the center and the periphery of a long body phantom with a commercial solid-state detector. A weighted dose profile is then calculated from these measurements. To calculate the CT dosimetric quantities analytically, a Gaussian function was fitted to the dose profile data. Furthermore, the Gaussian model has the power to condense the z-axis information of the dose profile in two parameters: The single-scan central dose, f(0), and the width of the profile, {sigma}. To check the energy dependence of the solid-state detector, the authors compared the dose profiles to measurements made with a small volume ion chamber. To validate the overall method, the authors compared the CTDI{sub 100} calculated analytically to the measurement made with a 100 mm pencil ion chamber. Results: For the central and weighted dose profiles, the authors found a good agreement between the measured dose profile data and the fitted Gaussian functions. The solid-state detector had no energy dependence--within the energy range of interest--and the analytical model succeeded in reproducing the absolute dose values obtained with the pencil ion chamber. For the case of large cone-beam single axial scans, the quantity that better characterizes the total energy imparted to the patient is the weighted dose profile integral (DPI{sub w}). The DPI{sub w} can be easily determined from the two parameters that define the Gaussian functions: f(0) and {sigma}. The authors found that the DLP underestimated the total energy imparted to the patient by more than 20%. The authors also found that the calculated CT dosimetric quantities were higher than those displayed on the scanner console. Conclusions: The authors described and validated a method to assess radiation dose in large cone-beam single axial scans. This method offers a simple and more accurate estimation of the total energy imparted to the patient, thus offering the possibility to update the bridge between CT dosimetry and the estimation of the effective dose for cone-beam CT examinations in radiology, nuclear medicine, and radiation therapy.

  18. 7 Tesla (T) human cardiovascular magnetic resonance imaging using FLASH and SSFP to assess cardiac function: validation against 1.5 T and 3 T

    PubMed Central

    Suttie, J. J.; DelaBarre, L.; Pitcher, A.; van de Moortele, P. F.; Dass, S.; Snyder, C. J.; Francis, J. M.; Metzger, G. J.; Weale, P.; Ugurbil, K.; Neubauer, S.; Robson, M.; Vaughan, T.

    2012-01-01

    We report the first comparison of cardiovascular magnetic resonance imaging (CMR) at 1.5 T, 3 T and 7 T field strengths using steady state free precession (SSFP) and fast low angle shot (FLASH) cine sequences. Cardiac volumes and mass measurements were assessed for feasibility, reproducibility and validity at each given field strength using FLASH and SSFP sequences. Ten healthy volunteers underwent retrospectively electrocardiogram (ECG) gated CMR at 1.5 T, 3 T and 7 T using FLASH and SSFP sequences. B1 and B0 shimming and frequency scouts were used to optimise image quality. Cardiac volume and mass measurements were not significantly affected by field strength when using the same imaging sequence (P > 0.05 for all parameters at 1.5 T, 3 T and 7 T). SSFP imaging returned larger end diastolic and end systolic volumes and smaller left ventricular masses than FLASH imaging at 7 T, and at the lower field strengths (P < 0.05 for each parameter). However, univariate general linear model analysis with fixed effects for sequence and field strengths found an interaction between imaging sequence and field strength (P = 0.03), with a smaller difference in volumes and mass measurements between SSFP and FLASH imaging at 7 T than 1.5 T and 3 T. SSFP and FLASH cine imaging at 7 T is technically feasible and provides valid assessment of cardiac volumes and mass compared with CMR imaging at 1.5 T and 3 T field strengths. PMID:21774009

  19. Anti-addiction drug ibogaine inhibits voltage-gated ionic currents: A study to assess the drug's cardiac ion channel profile

    SciTech Connect

    Koenig, Xaver; Kovar, Michael; Rubi, Lena; Mike, Agnes K.; Lukacs, Peter; Gawali, Vaibhavkumar S.; Todt, Hannes; Hilber, Karlheinz; Sandtner, Walter

    2013-12-01

    The plant alkaloid ibogaine has promising anti-addictive properties. Albeit not licenced as a therapeutic drug, and despite hints that ibogaine may perturb the heart rhythm, this alkaloid is used to treat drug addicts. We have recently reported that ibogaine inhibits human ERG (hERG) potassium channels at concentrations similar to the drugs affinity for several of its known brain targets. Thereby the drug may disturb the heart's electrophysiology. Here, to assess the drug's cardiac ion channel profile in more detail, we studied the effects of ibogaine and its congener 18-Methoxycoronaridine (18-MC) on various cardiac voltage-gated ion channels. We confirmed that heterologously expressed hERG currents are reduced by ibogaine in low micromolar concentrations. Moreover, at higher concentrations, the drug also reduced human Na{sub v}1.5 sodium and Ca{sub v}1.2 calcium currents. Ion currents were as well reduced by 18-MC, yet with diminished potency. Unexpectedly, although blocking hERG channels, ibogaine did not prolong the action potential (AP) in guinea pig cardiomyocytes at low micromolar concentrations. Higher concentrations (≥ 10 μM) even shortened the AP. These findings can be explained by the drug's calcium channel inhibition, which counteracts the AP-prolonging effect generated by hERG blockade. Implementation of ibogaine's inhibitory effects on human ion channels in a computer model of a ventricular cardiomyocyte, on the other hand, suggested that ibogaine does prolong the AP in the human heart. We conclude that therapeutic concentrations of ibogaine have the propensity to prolong the QT interval of the electrocardiogram in humans. In some cases this may lead to cardiac arrhythmias. - Highlights: • We study effects of anti-addiction drug ibogaine on ionic currents in cardiomyocytes. • We assess the cardiac ion channel profile of ibogaine. • Ibogaine inhibits hERG potassium, sodium and calcium channels. • Ibogaine’s effects on ion channels are a potential source of cardiac arrhythmias. • 18-Methoxycoronaridine has a lower affinity for cardiac ion channels than ibogaine.

  20. Assessment of phase based dose modulation for improved dose efficiency in cardiac CT on an anthropomorphic motion phantom

    NASA Astrophysics Data System (ADS)

    Budde, Adam; Nilsen, Roy; Nett, Brian

    2014-03-01

    State of the art automatic exposure control modulates the tube current across view angle and Z based on patient anatomy for use in axial full scan reconstructions. Cardiac CT, however, uses a fundamentally different image reconstruction that applies a temporal weighting to reduce motion artifacts. This paper describes a phase based mA modulation that goes beyond axial and ECG modulation; it uses knowledge of the temporal view weighting applied within the reconstruction algorithm to improve dose efficiency in cardiac CT scanning. Using physical phantoms and synthetic noise emulation, we measure how knowledge of sinogram temporal weighting and the prescribed cardiac phase can be used to improve dose efficiency. First, we validated that a synthetic CT noise emulation method produced realistic image noise. Next, we used the CT noise emulation method to simulate mA modulation on scans of a physical anthropomorphic phantom where a motion profile corresponding to a heart rate of 60 beats per minute was used. The CT noise emulation method matched noise to lower dose scans across the image within 1.5% relative error. Using this noise emulation method to simulate modulating the mA while keeping the total dose constant, the image variance was reduced by an average of 11.9% on a scan with 50 msec padding, demonstrating improved dose efficiency. Radiation dose reduction in cardiac CT can be achieved while maintaining the same level of image noise through phase based dose modulation that incorporates knowledge of the cardiac reconstruction algorithm.

  1. Cardiac metastases

    PubMed Central

    Bussani, R; De‐Giorgio, F; Abbate, A; Silvestri, F

    2007-01-01

    Tumours metastatic to the heart (cardiac metastases) are among the least known and highly debated issues in oncology, and few systematic studies are devoted to this topic. Although primary cardiac tumours are extremely uncommon (various postmortem studies report rates between 0.001% and 0.28%), secondary tumours are not, and at least in theory, the heart can be metastasised by any malignant neoplasm able to spread to distant sites. In general, cardiac metastases are considered to be rare; however, when sought for, the incidence seems to be not as low as expected, ranging from 2.3% and 18.3%. Although no malignant tumours are known that diffuse preferentially to the heart, some do involve the heart more often than others—for example, melanoma and mediastinal primary tumours. This paper attempts to review the pathophysiology of cardiac metastatic disease, epidemiology and clinical presentation of cardiac metastases, and pathological characterisation of the lesions. PMID:17098886

  2. Comparisons of four categories of waste recycling in China's paper industry based on physical input-output life-cycle assessment model.

    PubMed

    Liang, Sai; Zhang, Tianzhu; Xu, Yijian

    2012-03-01

    Waste recycling for paper production is an important component of waste management. This study constructs a physical input-output life-cycle assessment (PIO-LCA) model. The PIO-LCA model is used to investigate environmental impacts of four categories of waste recycling in China's paper industry: crop straws, bagasse, textile wastes and scrap paper. Crop straw recycling and wood utilization for paper production have small total intensity of environmental impacts. Moreover, environmental impacts reduction of crop straw recycling and wood utilization benefits the most from technology development. Thus, using crop straws and wood (including wood wastes) for paper production should be promoted. Technology development has small effects on environmental impacts reduction of bagasse recycling, textile waste recycling and scrap paper recycling. In addition, bagasse recycling and textile waste recycling have big total intensity of environmental impacts. Thus, the development of bagasse recycling and textile waste recycling should be properly limited. Other pathways for reusing bagasse and textile wastes should be explored and evaluated. Moreover, imports of scrap paper should be encouraged to reduce large indirect impacts of scrap paper recycling on domestic environment. PMID:22100716

  3. Comparisons of four categories of waste recycling in China's paper industry based on physical input-output life-cycle assessment model

    SciTech Connect

    Liang Sai; Zhang, Tianzhu; Xu Yijian

    2012-03-15

    Highlights: Black-Right-Pointing-Pointer Using crop straws and wood wastes for paper production should be promoted. Black-Right-Pointing-Pointer Bagasse and textile waste recycling should be properly limited. Black-Right-Pointing-Pointer Imports of scrap paper should be encouraged. Black-Right-Pointing-Pointer Sensitivity analysis, uncertainties and policy implications are discussed. - Abstract: Waste recycling for paper production is an important component of waste management. This study constructs a physical input-output life-cycle assessment (PIO-LCA) model. The PIO-LCA model is used to investigate environmental impacts of four categories of waste recycling in China's paper industry: crop straws, bagasse, textile wastes and scrap paper. Crop straw recycling and wood utilization for paper production have small total intensity of environmental impacts. Moreover, environmental impacts reduction of crop straw recycling and wood utilization benefits the most from technology development. Thus, using crop straws and wood (including wood wastes) for paper production should be promoted. Technology development has small effects on environmental impacts reduction of bagasse recycling, textile waste recycling and scrap paper recycling. In addition, bagasse recycling and textile waste recycling have big total intensity of environmental impacts. Thus, the development of bagasse recycling and textile waste recycling should be properly limited. Other pathways for reusing bagasse and textile wastes should be explored and evaluated. Moreover, imports of scrap paper should be encouraged to reduce large indirect impacts of scrap paper recycling on domestic environment.

  4. Assessment of Left Ventricular Function in Cardiac MSCT Imaging by a 4D Hierarchical Surface-Volume Matching Process.

    PubMed

    Garreau, Mireille; Simon, Antoine; Boulmier, Dominique; Coatrieux, Jean-Louis; Le Breton, Hervé

    2006-01-01

    Multislice computed tomography (MSCT) scanners offer new perspectives for cardiac kinetics evaluation with 4D dynamic sequences of high contrast and spatiotemporal resolutions. A new method is proposed for cardiac motion extraction in multislice CT. Based on a 4D hierarchical surface-volume matching process, it provides the detection of the heart left cavities along the acquired sequence and the estimation of their 3D surface velocity fields. A Markov random field model is defined to find, according to topological descriptors, the best correspondences between a 3D mesh describing the left endocardium at one time and the 3D acquired volume at the following time. The global optimization of the correspondences is realized with a multiresolution process. Results obtained on simulated and real data show the capabilities to extract clinically relevant global and local motion parameters and highlight new perspectives in cardiac computed tomography imaging. PMID:23165027

  5. Use of an Implantable Loop Recorder in a Chimpanzee (Pan troglodytes) to Monitor Cardiac Arrhythmias and Assess the Effects of Acupuncture and Laser Therapy.

    PubMed

    Magden, Elizabeth R; Sleeper, Meg M; Buchl, Stephanie J; Jones, Rebekah A; Thiele, Erica J; Wilkerson, Gregory K

    2016-01-01

    Cardiovascular disease is a leading cause of death in captive chimpanzees and is often associated with myocardial fibrosis, which increases the risk of cardiac arrhythmias. In this case report, we present a 36-y-old male chimpanzee (Pan troglodytes) diagnosed with frequent ventricular premature complexes (VPC). We placed a subcutaneous implantable loop recorder for continual ECG monitoring to assess his arrhythmias without the confounding effects of anesthetics. During his initial treatment with the antiarrhythmia medication amiodarone, he developed thrombocytopenia, and the drug was discontinued. After reviewing other potential therapies for the treatment of cardiac arrhythmias, we elected to try acupuncture and laser therapy in view of the positive results and the lack of adverse side effects reported in humans. We used 2 well-known cardiac acupuncture sites on the wrist, PC6 (pericardium 6) and HT7 (heart 7), and evaluated the results of the therapy by using the ECG recordings from the implantable loop recorder. Although periodic increases in the animal's excitement level introduced confounding variables that caused some variation in the data, acupuncture and laser therapy appeared to decrease the mean number of VPC/min in this chimpanzee. PMID:26884410

  6. Necessity of angiotensin-converting enzyme-related gene for cardiac functions and longevity of Drosophila melanogaster assessed by optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Liao, Fang-Tsu; Chang, Cheng-Yi; Su, Ming-Tsan; Kuo, Wen-Chuan

    2014-01-01

    Prior studies have established the necessity of an angiotensin-converting enzyme-related (ACER) gene for heart morphogenesis of Drosophila. Nevertheless, the physiology of ACER has yet to be comprehensively understood. Herein, we employed RNA interference to down-regulate the expression of ACER in Drosophila's heart and swept source optical coherence tomography to assess whether ACER is required for cardiac functions in living adult flies. Several contractile parameters of Drosophila heart, including the heart rate (HR), end-diastolic diameter (EDD), end-systolic diameter (ESD), percent fractional shortening (%FS), and stress-induced cardiac performance, are shown, which are age dependent. These age-dependent cardiac functions declined significantly when ACER was down-regulated. Moreover, the lifespans of ACER knock-down flies were significantly shorter than those of wild-type control flies. Thus, we posit that ACER, the Drosophila ortholog of mammalian angiotensin-converting enzyme 2 (ACE2), is essential for both heart physiology and longevity of animals. Since mammalian ACE2 controls many cardiovascular physiological features and is implicated in cardiomyopathies, our findings that ACER plays conserved roles in genetically tractable animals will pave the way for uncovering the genetic pathway that controls the renin-angiotensin system.

  7. A pilot study to assess the feasibility of a submaximal exercise test to measure individual response to cardiac medication in dogs with acquired heart failure.

    PubMed

    Ferasin, L; Marcora, S

    2007-08-01

    Exercise testing is not commonly used in canine medicine because of several limitations. The aim of this study was to investigate the suitability of a treadmill test to measure the exercise capacity of untrained canine cardiac patients and to measure some biological parameters that might reflect the tolerance of dogs with heart failure to submaximal exercise. The exercise capacity of seven dogs with naturally occurring heart failure was evaluated before the institution of cardiac medication and 7 days after the beginning of the study. An additional re-examination was requested after 28 days. The exercise test was performed on a motorized treadmill at three different speeds (0.5 m/s, 1.0 m/s and 1.5 m/s). The following parameters were measured at the end of each stage and after 20 min recovery: heart rate, rectal temperature, glucose, lactate, aspartate aminotransferase, creatine kinase, PvO(2), PvCO(2), pH, haematocrit, bicarbonate, sodium, potassium and chloride. Serum cardiac troponin-I was also measured at the beginning of the test and at the end of the recovery period. Owners' perception reflected the ability of their dogs to exercise on the treadmill. Lactate level increased noticeably with the intensity of the exercise test, and its variation coincided with different exercise tolerance observed by the owners. Heart rate seemed to follow a similar trend in the few dogs presented in sinus rhythm. None of the remaining parameters appeared to be sensitive indicators of activity level in the dogs used in this study. The treadmill exercise test in dogs with acquired heart failure is feasible and might provide useful information for assessing individual response to cardiac medication. Lactate and heart rate seemed to reflect individual levels of exercise tolerance, although further studies are necessary to confirm the reliability and repeatability of this test. PMID:17253114

  8. Assessment of the Right Ventricular Function and Mass Using Cardiac Multi-Detector Computed Tomography in Patients with Chronic Obstructive Pulmonary Disease

    PubMed Central

    Hur, Jin; Kim, Sang Jin; Ryu, Young Hoon; Kim, Hyung Jung

    2007-01-01

    Objective We wanted to assess the relationship between measurements of the right ventricular (RV) function and mass, with using cardiac multi-detector computed tomography (MDCT) and the severity of chronic obstructive pulmonary disease (COPD) as determined by the pulmonary function test (PFT). Materials and Methods Measurements of PFT and cardiac MDCT were obtained in 33 COPD patients. Using the Global Initiative for Chronic Obstructive Lung Disease (GOLD) classification, the patients were divided into three groups according to the severity of the disease: stage I (mild, n = 4), stage II (moderate, n = 15) and stage III (severe, n = 14). The RV function and the wall mass were obtained by cardiac MDCT. The results were compared among the groups using the Student-Newman-Keuls method. Pearson's correlation was used to evaluate the relationship between the right ventricular ejection fraction (RVEF) and the wall mass results with the PFT results. P-values less than 0.05 were considered statistically significant. Results The RVEF and mass were 47±3% and 41±2 g in stage I, 46±6% and 46±5 g in stage II, and 35±5% and 55±6 g in stage III, respectively. The RVEF was significantly lower in stage III than in stage I and II (p < 0.01). The RV mass was significantly different among the three stages, according to the disease severity of COPD (p < 0.05). The correlation was excellent between the MDCT results and forced expiratory volume in 1 sec (r = 0.797 for RVEF and r = -0.769 for RV mass) and forced expiratory volume in 1 sec to the forced vital capacity (r = 0.745 for RVEF and r = -0.718 for RV mass). Conclusion Our study shows that the mean RV wall mass as measured by cardiac MDCT correlates well with the COPD disease severity as determined by PFT. PMID:17277559

  9. Assessment of DNA double-strand breaks induced by intravascular iodinated contrast media following in vitro irradiation and in vivo, during paediatric cardiac catheterization.

    PubMed

    Gould, Richard; McFadden, Sonyia L; Horn, Simon; Prise, Kevin M; Doyle, Philip; Hughes, Ciara M

    2016-03-01

    Paediatric cardiac catheterizations may result in the administration of substantial amounts of iodinated contrast media and ionizing radiation. The aim of this work was to investigate the effect of iodinated contrast media in combination with in vitro and in vivo X-ray radiation on lymphocyte DNA. Six concentrations of iodine (15, 17.5, 30, 35, 45, and 52.5 mg of iodine per mL blood) represented volumes of iodinated contrast media used in the clinical setting. Blood obtained from healthy volunteers was mixed with iodinated contrast media and exposed to radiation doses commonly used in paediatric cardiac catheterizations (0 mGy, 70 mGy, 140 mGy, 250 mGy and 450 mGy). Control samples contained no iodine. For in vivo experimentation, pre and post blood samples were collected from children undergoing cardiac catheterization, receiving iodine concentrations of up to 51 mg of iodine per mL blood and radiation doses of up to 400 mGy. Fluorescence microscopy was performed to assess γH2AX-foci induction, which corresponded to the number of DNA double-strand breaks. The presence of iodine in vitro resulted in significant increases of DNA double-strand breaks beyond that induced by radiation for ≥17.5 mg/mL iodine to blood. The in vivo effects of contrast media on children undergoing cardiac catheterization resulted in a 19% increase in DNA double-strand breaks in children receiving an average concentration of 19 mg/mL iodine to blood. A larger investigation is required to provide further information of the potential benefit of lowering the amount of iodinated contrast media received during X-ray radiation investigations. Copyright © 2015 John Wiley & Sons, Ltd. PMID:26549792

  10. Nonexercise cardiac stress testing

    SciTech Connect

    Vacek, J.L.; Baldwin, T. )

    1989-09-15

    Many patients who require evaluation for coronary artery disease are unable to undergo exercise stress testing because of physiologic or psychological limitations. Drs Vacek and Baldwin describe three alternative methods for assessment of cardiac function in these patients, all of which have high levels of diagnostic sensitivity and specificity. 23 references.

  11. Digital cardiac imaging

    SciTech Connect

    Buda, A.J.; Delp, E.J.

    1985-01-01

    This book contains 16 papers. Some of the titles are: The analysis of left ventricular function with digital subtraction angiography; Digital radiographic assessment of coronary flow reserve; Clinical application of cardiac CT; Digital two-dimensional echocardiography; and Magnetic resonance imaging of the heart.

  12. Fetal cardiac function in intrauterine growth retardation.

    PubMed

    Rizzo, G; Arduini, D

    1991-10-01

    Blood-flow velocity waveforms are altered in several peripheral vascular beds of fetuses whose intrauterine growth is retarded because of placental insufficiency. We investigated these concomitant changes in cardiac function. Color and pulsed Doppler echocardiographic recordings were performed in 124 fetuses with intrauterine growth retardation. These fetuses were free of structural and chromosomal abnormalities and were characterized by increased umbilical artery resistance and reduced middle cerebral artery resistance. Twenty-four of these fetuses were also studied at weekly intervals until the onset of antepartum late heart rate decelerations. Blood-flow velocity waveforms were obtained from the aortic and pulmonary valves, and the following variables were measured: peak systolic velocity, time to peak velocity, the product of time velocity integral multiplied by heart rate, left and right cardiac output, and the right/left ratios of the product of time velocity integrals multiplied by heart rate and cardiac output. When compared with previously established norms, both aortic and pulmonary peak systolic velocities and pulmonary time to peak velocity were reduced; aortic time to peak velocity increased. Left cardiac output and the product of the aortic time velocity integral multiplied by the heart rate increased and right cardiac output and the product of the pulmonary time velocity integral multiplied by the heart rate decreased, resulting in reduced right/left ratios. In the 24 fetuses studied longitudinally, time to peak velocities and the right/left flow ratios remained stable. However, aortic and pulmonary peak velocities and cardiac output declined significantly in contrast to an expected rise with advancing gestation. The fall in cardiac output and aortic and pulmonary peak velocities was directly related to umbilical artery pH at birth. This study provides evidence of a modified cardiac function that seems to deteriorate progressively with the advancing gestation of fetuses with intrauterine growth retardation. PMID:1951546

  13. Assessing the Impacts of Climate Change on the Distribution of Trout Species in the Sierra Nevada Region of California Using Output from a Landscape Scale Hydrological Model

    NASA Astrophysics Data System (ADS)

    Anthony, M. M.; Ficklin, D. L.; Stewart, I. T.; Knouft, J.

    2014-12-01

    Species distribution models (SDMs) are statistical tools that combine data on the locations where a species is known to occur with data on the environment. The resulting species-environment relationships are then used to identify regions a species could occupy and are often used to make predictions about how a species will respond to climate change. The data used in SDMs generally exhibit a pattern known as spatial autocorrelation (SAC), which is the positive association between the proximity of sample locations. The presence of SAC violates the statistical assumptions that must be met for unbiased estimation of species-environment relationships and can cause traditional SDMs to exhibit low predictive accuracy. To determine the effects of SAC on predicting species' responses to climate change, the distributions of three species of trout were predicted throughout the Sierra Nevada mountain range in California. Measures of contemporary streamflow, water temperature, dissolved oxygen, and sediment concentration are based on model outputs from the Soil and Water Assessment Tool (SWAT) landscape scale hydrological model. SWAT-derived future hydrological conditions driven by downscaled General Circulation Models (GCMs) indicate that increasing temperatures and changes in precipitation will alter these variables across the region, all of which have the ability to negatively impact the distribution of trout species. Trout distribution data along with data on contemporary stream flow, water temperature, dissolved oxygen and sediment concentration from the years 1990 to 1999 were used to develop both spatial and non-spatial SDMs for each species. These species-environment relationships along with data on future environmental conditions for the years 2050-2059 derived from three separate GCM scenarios were then used to predict the future distribution of each species. Predictions from spatial and non-spatial models will be discussed with a focus on the difference in area and the amount of overlap between current and future distributions of each species.

  14. Cardiac Rehabilitation

    MedlinePlus

    Cardiac rehabilitation (rehab) is a medically supervised program to help people who have A heart attack Angioplasty or coronary artery bypass grafting for coronary heart disease A heart valve repair or replacement A ...

  15. Cardiac Sarcoidosis

    MedlinePlus

    ... do at National Jewish Health? We provide comprehensive cardiology evaluation and consultation and non-invasive cardiac testing. ... the whole person, not just the disease. Our cardiology team works with healthcare providers from all areas ...

  16. Cardiac CT

    MedlinePlus

    ... type of CT scan is called a coronary CT angiography (an-je-OG-rah-fee), or CTA. Overview ... called atrial fibrillation (AF). The pictures that cardiac CT creates of the pulmonary veins can help guide procedures used to treat ...

  17. Cardiac Catheterization

    MedlinePlus

    ... done during a cardiac catheterization include: closing small holes inside the heart repairing leaky or narrow heart ... bandage. It's normal for the site to be black and blue, red, or slightly swollen for a ...

  18. Cardiac MRI

    MedlinePlus

    ... from the NHLBI on Twitter. What Is Cardiac MRI? Magnetic resonance imaging (MRI) is a safe, noninvasive test that creates detailed ... and no instruments are inserted into your body. MRI uses radio waves, magnets, and a computer to ...

  19. Cardiac Dysfunction during Exercise in Uncomplicated Type 2 Diabetes

    PubMed Central

    REGENSTEINER, JUDITH G.; BAUER, TIMOTHY A.; REUSCH, JANE E. B.; QUAIFE, ROBERT A.; CHEN, MARCUS Y.; SMITH, SUSAN C.; MILLER, TYLER M.; GROVES, BERTRON M.; WOLFEL, EUGENE E.

    2010-01-01

    Purpose Type 2 diabetes mellitus (T2DM) has been associated with reduced peak exercise capacity (V̇O2peak). The causes of this impairment are not clearly established, but evidence suggests that abnormalities in cardiac function play a significant role. We hypothesized that exercise would be associated with impaired cardiac function and hemodynamics in recently diagnosed T2DM, even in the absence of clinically evident cardiovascular complications. Methods After baseline normal echocardiography screening, 10 premenopausal women with uncomplicated T2DM (average duration of diagnosed T2DM, 3.6 yr) and 10 healthy nondiabetic women of similar age, weight, and activity levels performed a peak cardiopulmonary exercise test while instrumented with an indwelling pulmonary artery catheter for assessing cardiac function. On separate days, technetium-99m sestamibi (cardolite) imaging was performed to assess myocardial perfusion at rest and peak exercise in seven T2DM and seven control patients. Results Resting measures of cardiac hemodynamics were similar in T2DM and control subjects. Absolute V̇O2peak (mL·min−1) and peak cardiac output (L·min−1) tended to be lower in T2DM than in control subjects but did not reach statistical significance. However, pulmonary capillary wedge pressure (PCWP) rose significantly more during exercise in T2DM than in controls (148% vs 109% increase at peak exercise, P < 0.01). Normalized myocardial perfusion index was lower in persons with diabetes than in controls (11.0 ± 3.5 × e−9 vs 17.5 ± 8.1 × e−9, respectively, P < 0.05) and inversely related to peak exercise PCWP (R = −0.56, P < 0.05). Conclusions Cardiac hemodynamics during graded exercise are altered in women with recently diagnosed T2DM as demonstrated by the disproportionate increase in PCWP at peak exercise compared with controls subjects. Cardiac abnormalities observed are potentially early signs of subclinical cardiac dysfunction associated with T2DM, which may precede the more greatly impaired cardiac function at rest and with exercise observed in longer established T2DM. PMID:19346991

  20. Using MERRA, AMIP II, CMIP5 Outputs to Assess Actual and Potential Building Climate Zone Change and Variability From the Last 30 Years Through 2100

    NASA Astrophysics Data System (ADS)

    Stackhouse, P. W.; Westberg, D. J.; Hoell, J. M., Jr.; Chandler, W.; Zhang, T.

    2014-12-01

    In the US, residential and commercial building infrastructure combined consumes about 40% of total energy usage and emits about 39% of total CO2emission (DOE/EIA "Annual Energy Outlook 2013"). Thus, increasing the energy efficiency of buildings is paramount to reducing energy costs and emissions. Building codes, as used by local and state enforcement entities are typically tied to the dominant climate within an enforcement jurisdiction classified according to various climate zones. These climates zones are based upon a 30-year average of local surface observations and are developed by DOE and ASHRAE (formerly known as the American Society of Hearting, Refrigeration and Air-Conditioning Engineers). A significant shortcoming of the methodology used in constructing such maps is the use of surface observations (located mainly near airports) that are unequally distributed and frequently have periods of missing data that need to be filled by various approximation schemes. This paper demonstrates the usefulness of using NASA's Modern Era Retrospective-analysis for Research and Applications (MERRA) atmospheric data assimilation to derive the ASHRAE climate zone maps and then using MERRA to define the last 30 years of variability in climate zones. These results show that there is a statistically significant increase in the area covered by warmer climate zones and some tendency for a reduction of area in colder climate zones that require longer time series to confirm. Using the uncertainties of the basic surface temperature and precipitation parameters from MERRA as determined by comparison to surface measurements, we first compare patterns and variability of ASHRAE climate zones from MERRA relative to present day climate model runs from AMIP simulations to establish baseline sensitivity. Based upon these results, we assess the variability of the ASHRAE climate zones according to CMIP runs through 2100 using an ensemble analysis that classifies model output changes by percentiles. Estimates of statistical significance are then compared to original model variability during the AMIP period. This work quantifies and tests for significance the changes seen in the various US regions that represent a potential contribution by NASA to the ongoing National Climate Assessment.

  1. Cardiac cephalgia.

    PubMed

    Torres-Yaghi, Yasar; Salerian, Justin; Dougherty, Carrie

    2015-04-01

    "Cardiac cephalgia" is a type of secondary headache disorder, usually initiated by exertion that is related to myocardial ischemia. Primary exertional headaches such as sex-, cough-, or exercise-induced headaches are typically benign. Cardiac cephalgia, on the other hand, can have life-threatening complications. Due to overlapping features and similarities in presentation, cardiac cephalgia can be misdiagnosed as a primary headache disorder such as migraine. However, the management of these conditions is unique, and treatment of cardiac cephalgia with vasoconstrictors intended for migraine can potentially worsen myocardial ischemia. Thus, it is important to make the correct diagnosis by evaluating cardiac function with an electrocardiogram and/or stress testing. In this review, we examine reported cases of cardiac cephalgia from the past 5 years to highlight the importance of this condition in the differential diagnosis of a headache in a patient with a history of cardiovascular risk factors, as well as to discuss the appropriate approach to diagnosis and the proposed pathogenic mechanisms of this condition. PMID:25819974

  2. Cardiac catheterization and angiography, 3d Ed

    SciTech Connect

    Grossman, W.

    1986-01-01

    This textbook was first published in 1974 and subsequently revised in 1980. The current edition, in seven parts and 33 chapters, has been extensively rewritten, and new chapters have been added that present recently developed techniques. The references have been updated to 1985. The purpose of this work is to provide a concise description of the major techniques employed in cardiac catheterization and angiography. Part 1 deals with the history, general principles, and practice of cardiac catheterization and angiography. In part 2, various techniques of cardiac catheterization are discussed and compared. In part 3, techniques for the determination of cardiac output, pressure, resistance, valve area, and shunt flow are described. Part 4 deals briefly with coronary angiography, cardiac ventriculography, pulmonary angiography, and aortography. In part 5, techniques for evaluating cardiac function and intracardiac electrophysiology are presented. The characteristic hemodynamic and angiographic abnormalities in specific disorders are described in part 6. Part 7 deals with special catheter techniques.

  3. Feasibility of cognitive functional assessment in cardiac arrest survivors using an abbreviated laptop-based neurocognitive battery.

    PubMed

    Iannacone, Stephen; Leary, Marion; Esposito, Emily C; Ruparel, Kosha; Savitt, Adam; Mott, Allison; Richard, Jan A; Gur, Ruben C; Abella, Benjamin S

    2014-09-01

    Cardiac arrest survivors exhibit varying degrees of neurological recovery even in the setting of targeted temperature management (TTM) use, ranging from severe impairments to making a seemingly full return to neurologic baseline function. We sought to explore the feasibility of utilizing a laptop-based neurocognitive battery to identify more subtle cognitive deficits in this population. In a convenience sample of cardiac arrest survivors discharged with a cerebral performance category (CPC) of 1, we evaluated the use of a computerized neurocognitive battery (CNB) in this group compared to a healthy control normative population. The CNB was designed to test 11 specific neurocognitive domains, including such areas as working memory and spatial processing. Testing was scored for both accuracy and speed. In a feasibility convenience sample of 29 cardiac arrest survivors, the mean age was 52.9±16.7 years; 12 patients received postarrest TTM and 17 did not receive TTM. Patients tolerated the battery well and performed at normative levels for both accuracy and speed on most of the 11 domains, but showed reduced accuracy of working memory and speed of spatial memory with large magnitudes (>1 SD), even among those receiving TTM. Across all domains, including those using speed and accuracy, 7 of the 29 subjects (24%) achieved statistically significant scores lower from the normative population in two or more domains. In this population of CPC 1 cardiac arrest survivors, a sensitive neurocognitive battery was feasible and suggests that specific cognitive deficits can be detected compared to a normative population, despite CPC 1 designation. Such testing might allow improved measurement of outcomes following TTM interventions in future trials. PMID:25010524

  4. Feasibility of Cognitive Functional Assessment in Cardiac Arrest Survivors Using an Abbreviated Laptop-Based Neurocognitive Battery

    PubMed Central

    Iannacone, Stephen; Esposito, Emily C.; Ruparel, Kosha; Savitt, Adam; Mott, Allison; Richard, Jan A.; Gur, Ruben C.; Abella, Benjamin S.

    2014-01-01

    Cardiac arrest survivors exhibit varying degrees of neurological recovery even in the setting of targeted temperature management (TTM) use, ranging from severe impairments to making a seemingly full return to neurologic baseline function. We sought to explore the feasibility of utilizing a laptop-based neurocognitive battery to identify more subtle cognitive deficits in this population. In a convenience sample of cardiac arrest survivors discharged with a cerebral performance category (CPC) of 1, we evaluated the use of a computerized neurocognitive battery (CNB) in this group compared to a healthy control normative population. The CNB was designed to test 11 specific neurocognitive domains, including such areas as working memory and spatial processing. Testing was scored for both accuracy and speed. In a feasibility convenience sample of 29 cardiac arrest survivors, the mean age was 52.9±16.7 years; 12 patients received postarrest TTM and 17 did not receive TTM. Patients tolerated the battery well and performed at normative levels for both accuracy and speed on most of the 11 domains, but showed reduced accuracy of working memory and speed of spatial memory with large magnitudes (>1 SD), even among those receiving TTM. Across all domains, including those using speed and accuracy, 7 of the 29 subjects (24%) achieved statistically significant scores lower from the normative population in two or more domains. In this population of CPC 1 cardiac arrest survivors, a sensitive neurocognitive battery was feasible and suggests that specific cognitive deficits can be detected compared to a normative population, despite CPC 1 designation. Such testing might allow improved measurement of outcomes following TTM interventions in future trials. PMID:25010524

  5. Echocardiographic assessment of left ventricular function in thyrotoxicosis and implications for the therapeutics of thyrotoxic cardiac disease

    PubMed Central

    Anakwue, Raphael C; Onwubere, Basden J; Ikeh, Vincent; Anisiuba, Benedict; Ike, Samuel; Anakwue, Angel-Mary C

    2015-01-01

    Introduction Thyrotoxicosis is an endocrine disorder with prominent cardiovascular manifestations. Thyroid hormone acts through genomic and non-genomic mechanisms to regulate cardiac function. Echocardiography is a useful, non-invasive, easily accessible, and affordable tool for studying the structural and physiological function of the heart. Aim We studied thyrotoxicosis patients in a Nigerian Teaching Hospital and employed trans-thoracic echocardiography to find out if there were abnormalities in the hearts of these patients. Methods Fifty adult thyrotoxicosis patients diagnosed with clinical and thyroid function tests in the medical out-patient unit of the hospital were recruited and we performed transthoracic echocardiography with a Sonos 2000 HP machine. Results We documented the presence of abnormalities in the following proportion of thyrotoxicosis patients: left ventricular enhanced systolic function in 30%, enhanced diastolic function in 34%, diastolic dysfunction in 34%, heart failure with preserved ejection fraction in10%, heart failure with reduced ejection fraction in 6%, and left ventricular hypertrophy in 34%. Conclusion Echocardiography was useful in the stratification of cardiac function abnormalities and is indispensable as a guide in the choice of therapeutic options in patients with thyrocardiac disease. The finding of left ventricular enhanced systolic and diastolic functions signify early echocardiographic detectable cardiac abnormalities in thyrotoxicosis, and the clinical management includes the use of anti-thyroid drugs and β-adrenoceptor blockade. Diastolic dysfunction in thyrotoxicosis patients asymptomatic for cardiac disease should be treated with anti-thyroid drugs, and β-adrenoceptor blockade. The judicious application of clinical therapeutics will guide the use of anti-thyroid drugs, diuretics, digoxin, angiotensin inhibitors, and β-adrenoceptor blockade in the successful management of thyrotoxicosis patients with heart failure and reduced, preserved, or increased ejection fraction: parameters which are derived from echocardiography. PMID:25709461

  6. Magnetic Resonance Elastography as a Method for the Assessment of Effective Myocardial Stiffness throughout the Cardiac Cycle

    PubMed Central

    Kolipaka, Arunark; Araoz, Philip A.; McGee, Kiaran P.; Manduca, Armando; Ehman, Richard L.

    2011-01-01

    Magnetic resonance elastography (MRE) is a noninvasive technique in which images of externally generated waves propagating in tissue are used to measure stiffness. The first aim is to determine, from a range of driver configurations the optimal driver for the purpose of generating waves within the heart in vivo. The second aim is to quantify the shear stiffness of normal myocardium throughout the cardiac cycle using MRE and to compare MRE stiffness to left ventricular (LV) chamber pressure in an in vivo pig model. MRE was performed in 6-pigs with 6-different driver setups including no motion, 3-noninvasive drivers and 2-invasive drivers. MRE wave displacement amplitudes were calculated for each driver. During the same MRI examination, LV pressure and MRI-measured LV volume were obtained, and MRE myocardial stiffness was calculated for 20 phases of the cardiac cycle. No discernible waves were imaged when no external motion was applied, and a single pneumatic drum driver produced higher amplitude waves than the other noninvasive drivers (P <0.05). Pressure-volume loops overlaid onto stiffness-volume loops showed good visual agreement. Pressure and MRE-measured effective stiffness showed good correlation (R2 = 0.84). MRE shows potential as a noninvasive method for estimating effective myocardial stiffness throughout the cardiac cycle. PMID:20578052

  7. Functional Assessment of Cardiac Responses of Adult Zebrafish (Danio rerio) to Acute and Chronic Temperature Change Using High-Resolution Echocardiography.

    PubMed

    Lee, Ling; Genge, Christine E; Cua, Michelle; Sheng, Xiaoye; Rayani, Kaveh; Beg, Mirza F; Sarunic, Marinko V; Tibbits, Glen F

    2016-01-01

    The zebrafish (Danio rerio) is an important organism as a model for understanding vertebrate cardiovascular development. However, little is known about adult ZF cardiac function and how contractile function changes to cope with fluctuations in ambient temperature. The goals of this study were to: 1) determine if high resolution echocardiography (HRE) in the presence of reduced cardiodepressant anesthetics could be used to accurately investigate the structural and functional properties of the ZF heart and 2) if the effect of ambient temperature changes both acutely and chronically could be determined non-invasively using HRE in vivo. Heart rate (HR) appears to be the critical factor in modifying cardiac output (CO) with ambient temperature fluctuation as it increases from 78 5.9 bpm at 18C to 162 9.7 bpm at 28C regardless of acclimation state (cold acclimated CA- 18C; warm acclimated WA- 28C). Stroke volume (SV) is highest when the ambient temperature matches the acclimation temperature, though this difference did not constitute a significant effect (CA 1.17 0.15 ?L at 18C vs 1.06 0.14 ?l at 28C; WA 1.10 0.13 ?L at 18C vs 1.12 0.12 ?l at 28C). The isovolumetric contraction time (IVCT) was significantly shorter in CA fish at 18C. The CA group showed improved systolic function at 18C in comparison to the WA group with significant increases in both ejection fraction and fractional shortening and decreases in IVCT. The decreased early peak (E) velocity and early peak velocity / atrial peak velocity (E/A) ratio in the CA group are likely associated with increased reliance on atrial contraction for ventricular filling. PMID:26730947

  8. Functional Assessment of Cardiac Responses of Adult Zebrafish (Danio rerio) to Acute and Chronic Temperature Change Using High-Resolution Echocardiography

    PubMed Central

    Cua, Michelle; Sheng, Xiaoye; Rayani, Kaveh; Beg, Mirza F.; Sarunic, Marinko V.; Tibbits, Glen F.

    2016-01-01

    The zebrafish (Danio rerio) is an important organism as a model for understanding vertebrate cardiovascular development. However, little is known about adult ZF cardiac function and how contractile function changes to cope with fluctuations in ambient temperature. The goals of this study were to: 1) determine if high resolution echocardiography (HRE) in the presence of reduced cardiodepressant anesthetics could be used to accurately investigate the structural and functional properties of the ZF heart and 2) if the effect of ambient temperature changes both acutely and chronically could be determined non-invasively using HRE in vivo. Heart rate (HR) appears to be the critical factor in modifying cardiac output (CO) with ambient temperature fluctuation as it increases from 78 ± 5.9 bpm at 18°C to 162 ± 9.7 bpm at 28°C regardless of acclimation state (cold acclimated CA– 18°C; warm acclimated WA– 28°C). Stroke volume (SV) is highest when the ambient temperature matches the acclimation temperature, though this difference did not constitute a significant effect (CA 1.17 ± 0.15 μL at 18°C vs 1.06 ± 0.14 μl at 28°C; WA 1.10 ± 0.13 μL at 18°C vs 1.12 ± 0.12 μl at 28°C). The isovolumetric contraction time (IVCT) was significantly shorter in CA fish at 18°C. The CA group showed improved systolic function at 18°C in comparison to the WA group with significant increases in both ejection fraction and fractional shortening and decreases in IVCT. The decreased early peak (E) velocity and early peak velocity / atrial peak velocity (E/A) ratio in the CA group are likely associated with increased reliance on atrial contraction for ventricular filling. PMID:26730947

  9. Adverse Left Ventricular Remodeling and Age Assessed with Cardiac MR Imaging: The Multi-Ethnic Study of Atherosclerosis.

    PubMed

    Eng, John; McClelland, Robyn L; Gomes, Antoinette S; Hundley, W Gregory; Cheng, Susan; Wu, Colin O; Carr, J Jeffrey; Shea, Steven; Bluemke, David A; Lima, Joao A C

    2016-03-01

    Purpose To evaluate age-related left ventricular (LV) remodeling during longitudinal observation of a large cohort of asymptomatic individuals who were free of clinical cardiovascular disease at baseline. Materials and Methods The applicable institutional review boards approved this study, and all participants gave informed consent. Cardiac magnetic resonance (MR) imaging was used to identify longitudinal changes in LV structure and function in 2935 participants who underwent baseline and follow-up cardiac MR imaging in the Multi-Ethnic Study of Atherosclerosis. Participants were free of clinical cardiovascular disease at baseline. Participants who experienced an incident coronary heart disease event were excluded. Data were analyzed with multivariable mixed-effects regression models in which the outcome was cardiac MR imaging measurement, and the covariates included follow-up time and cardiac risk factors. Results Participants were aged 54-94 years at follow-up, and 53% of the participants were women. Median time between baseline and follow-up cardiac MR imaging was 9.4 years. Over this period, LV mass increased in men and decreased slightly in women (8.0 and -1.6 g per decade, respectively; P < .001). In both men and women, LV end-diastolic volume decreased (-9.8 and -13.3 mL per decade, respectively; P < .001), stroke volume decreased (-8.8 and -8.6 mL per decade, respectively; P < .001), and mass-to-volume ratio increased (0.14 and 0.11 g/mL per decade, respectively; P < .001). Change in LV mass was positively associated with systolic blood pressure and body mass index and negatively associated with treated hypertension and high-density lipoprotein cholesterol level. In men, the longitudinal LV mass increase was in contrast to a cross-sectional pattern of LV mass decrease. Conclusion As patients age, the LV responds differently in its mass and volume between men and women, although both men and women experience increased concentric LV remodeling with age. In men, the opposition of longitudinal and cross-sectional changes in LV mass highlights the importance of longitudinal study. (©) RSNA, 2015 Online supplemental material is available for this article. PMID:26485617

  10. Hard copy output technologies

    SciTech Connect

    Herzog, D.G.

    1987-01-01

    This book contains the proceedings from the January 13-14, 1987 conference sponsored by SPIE - The International Society for Optical Engineering. The four sessions covered the following topics: Electronic Printing and Hard Copy Output Technologies; Recording and Printing Media; Hard Copy Output Technologies - Business Graphics; and High Resolution Printing and Recording Systems. Eighteen papers are presented in this volume.

  11. Cardiac sarcoidosis

    PubMed Central

    Smedema, J.P.; Zondervan, P.E.; van Hagen, P.; ten Cate, F.J.; Bresser, P.; Doubell, A.F.; Pattynama, P.; Hoogsteden, H.C.; Balk, A.H.M.M.

    2002-01-01

    Sarcoidosis is a multi-system granulomatous disorder of unknown aetiology. Symptomatic cardiac involvement occurs in approximately 5% of patients. The prevalence of sarcoidosis in the Netherlands is unknown, but estimated to be approximately 20 per 100,000 population (3200 patients). We report on five patients who presented with different manifestations of cardiac sarcoidosis, and give a brief review on the current management of this condition. Magnetic Resonance Imaging (MRI) can be of great help in diagnosing this condition as well as in the follow-up of the response to therapy. ImagesFigure 1Figure 2Figure 3Figure 4Figure 5Figure 6 PMID:25696121

  12. Anti-addiction drug ibogaine inhibits voltage-gated ionic currents: A study to assess the drug's cardiac ion channel profile☆

    PubMed Central

    Koenig, Xaver; Kovar, Michael; Rubi, Lena; Mike, Agnes K.; Lukacs, Peter; Gawali, Vaibhavkumar S.; Todt, Hannes; Hilber, Karlheinz; Sandtner, Walter

    2013-01-01

    The plant alkaloid ibogaine has promising anti-addictive properties. Albeit not licenced as a therapeutic drug, and despite hints that ibogaine may perturb the heart rhythm, this alkaloid is used to treat drug addicts. We have recently reported that ibogaine inhibits human ERG (hERG) potassium channels at concentrations similar to the drugs affinity for several of its known brain targets. Thereby the drug may disturb the heart's electrophysiology. Here, to assess the drug's cardiac ion channel profile in more detail, we studied the effects of ibogaine and its congener 18-Methoxycoronaridine (18-MC) on various cardiac voltage-gated ion channels. We confirmed that heterologously expressed hERG currents are reduced by ibogaine in low micromolar concentrations. Moreover, at higher concentrations, the drug also reduced human Nav1.5 sodium and Cav1.2 calcium currents. Ion currents were as well reduced by 18-MC, yet with diminished potency. Unexpectedly, although blocking hERG channels, ibogaine did not prolong the action potential (AP) in guinea pig cardiomyocytes at low micromolar concentrations. Higher concentrations (≥ 10 μM) even shortened the AP. These findings can be explained by the drug's calcium channel inhibition, which counteracts the AP-prolonging effect generated by hERG blockade. Implementation of ibogaine's inhibitory effects on human ion channels in a computer model of a ventricular cardiomyocyte, on the other hand, suggested that ibogaine does prolong the AP in the human heart. We conclude that therapeutic concentrations of ibogaine have the propensity to prolong the QT interval of the electrocardiogram in humans. In some cases this may lead to cardiac arrhythmias. PMID:23707769

  13. Anti-addiction drug ibogaine inhibits voltage-gated ionic currents: a study to assess the drug's cardiac ion channel profile.

    PubMed

    Koenig, Xaver; Kovar, Michael; Rubi, Lena; Mike, Agnes K; Lukacs, Peter; Gawali, Vaibhavkumar S; Todt, Hannes; Hilber, Karlheinz; Sandtner, Walter

    2013-12-01

    The plant alkaloid ibogaine has promising anti-addictive properties. Albeit not licensed as a therapeutic drug, and despite hints that ibogaine may perturb the heart rhythm, this alkaloid is used to treat drug addicts. We have recently reported that ibogaine inhibits human ERG (hERG) potassium channels at concentrations similar to the drugs affinity for several of its known brain targets. Thereby the drug may disturb the heart's electrophysiology. Here, to assess the drug's cardiac ion channel profile in more detail, we studied the effects of ibogaine and its congener 18-Methoxycoronaridine (18-MC) on various cardiac voltage-gated ion channels. We confirmed that heterologously expressed hERG currents are reduced by ibogaine in low micromolar concentrations. Moreover, at higher concentrations, the drug also reduced human Nav1.5 sodium and Cav1.2 calcium currents. Ion currents were as well reduced by 18-MC, yet with diminished potency. Unexpectedly, although blocking hERG channels, ibogaine did not prolong the action potential (AP) in guinea pig cardiomyocytes at low micromolar concentrations. Higher concentrations (≥ 10 μM) even shortened the AP. These findings can be explained by the drug's calcium channel inhibition, which counteracts the AP-prolonging effect generated by hERG blockade. Implementation of ibogaine's inhibitory effects on human ion channels in a computer model of a ventricular cardiomyocyte, on the other hand, suggested that ibogaine does prolong the AP in the human heart. We conclude that therapeutic concentrations of ibogaine have the propensity to prolong the QT interval of the electrocardiogram in humans. In some cases this may lead to cardiac arrhythmias. PMID:23707769

  14. Assessment of the dose distribution inside a cardiac cath lab using TLD measurements and Monte Carlo simulations

    NASA Astrophysics Data System (ADS)

    Baptista, M.; Teles, P.; Cardoso, G.; Vaz, P.

    2014-11-01

    Over the last decade, there was a substantial increase in the number of interventional cardiology procedures worldwide, and the corresponding ionizing radiation doses for both the medical staff and patients became a subject of concern. Interventional procedures in cardiology are normally very complex, resulting in long exposure times. Also, these interventions require the operator to work near the patient and, consequently, close to the primary X-ray beam. Moreover, due to the scattered radiation from the patient and the equipment, the medical staff is also exposed to a non-uniform radiation field that can lead to a significant exposure of sensitive body organs and tissues, such as the eye lens, the thyroid and the extremities. In order to better understand the spatial variation of the dose and dose rate distributions during an interventional cardiology procedure, the dose distribution around a C-arm fluoroscopic system, in operation in a cardiac cath lab at Portuguese Hospital, was estimated using both Monte Carlo (MC) simulations and dosimetric measurements. To model and simulate the cardiac cath lab, including the fluoroscopic equipment used to execute interventional procedures, the state-of-the-art MC radiation transport code MCNPX 2.7.0 was used. Subsequently, Thermo-Luminescent Detector (TLD) measurements were performed, in order to validate and support the simulation results obtained for the cath lab model. The preliminary results presented in this study reveal that the cardiac cath lab model was successfully validated, taking into account the good agreement between MC calculations and TLD measurements. The simulated results for the isodose curves related to the C-arm fluoroscopic system are also consistent with the dosimetric information provided by the equipment manufacturer (Siemens). The adequacy of the implemented computational model used to simulate complex procedures and map dose distributions around the operator and the medical staff is discussed, in view of the optimization principle (and the associated ALARA objective), one of the pillars of the international system of radiological protection.

  15. Dipyridamole cardiac imaging

    SciTech Connect

    Iskandrian, A.S.; Heo, J.; Askenase, A.; Segal, B.L.; Auerbach, N.

    1988-02-01

    Dipyridamole cardiac imaging is a useful alternative technique to exercise stress testing in the evaluation of patients with ischemic heart disease. Intravenous dipyridamole is still in the investigational phase, while oral dipyridamole is widely available. The hemodynamic effects of dipyridamole include an increase in coronary blood flow (due to coronary vasodilation) which is in excess of the increase in myocardial oxygen consumption and cardiac output. The disparity in the increase in coronary blood flow relative to the cardiac output results in an increase in myocardial thallium activity and an increase in the myocardial/background activity ratio. The quality of the thallium images is better or similar to that of exercise thallium images. The optimal dose of intravenous dipyridamole is 0.56 mg/kg, and of the oral dose it is 300 to 400 mg, although higher doses may be necessary in some patients. Analysis of the thallium images has been to a large extent based on visual inspection of the planar images. Delayed images are helpful to establish the nature of the perfusion abnormalities (transient or fixed). The process of redistribution is based on disparate rates of washout from the normal and abnormal zones. The sensitivity and specificity of dipyridamole thallium imaging, whether intravenous or oral, have been shown in a number of studies to be quite adequate and comparable to that achieved during exercise thallium imaging. Dipyridamole two-dimensional echocardiography has also been used in the detection of coronary artery disease; transient (new or worsening of preexisting) wall motion abnormalities have been found to be a specific marker of coronary artery disease. Transmural as well as regional coronary steal phenomena have been postulated as the mechanism for dipyridamole-induced regional wall motion abnormalities. 65 references.

  16. [Cardiac amyloidosis].

    PubMed

    Hoyer, Caroline; Angermann, Christiane E; Knop, Stefan; Ertl, Georg; Störk, Stefan

    2008-03-15

    Amyloidoses are a heterogeneous group of multisystem disorders, which are characterized by an extracellular deposition of amyloid fibrils. Typically affected are the heart, liver, kidneys, and nervous system. More than half of the patients die due to cardiac involvement. Clinical signs of cardiac amyloidosis are edema of the lower limbs, hepatomegaly, ascites and elevated jugular vein pressure, frequently in combination with dyspnea. There can also be chest pain, probably due to microvessel disease. Dysfunction of the autonomous nervous system or arrhythmias may cause low blood pressure, dizziness, or recurrent syncope. The AL amyloidosis caused by the deposition of immunoglobulin light chains is the most common form. It can be performed by monoclonal gammopathy. The desirable treatment therapy consists of high-dose melphalan therapy twice followed by autologous stem cell transplantation. Due to the high peritransplantation mortality, selection of appropriate patients is mandatory. The ATTR amyloidosis is an autosomal dominant disorder caused by the amyloidogenic form of transthyretin, a plasmaprotein that is synthesized in the liver. Therefore, liver transplantation is the only curative therapy. The symptomatic treatment of cardiac amyloidosis is based on the current guidelines for chronic heart failure according to the patient's New York Heart Association (NYHA) state. Further types of amyloidosis with possible cardiac involvement comprise the senile systemic amyloidosis caused by the wild-type transthyretin, secondary amyloidosis after chronic systemic inflammation, and the beta(2)-microglobulin amyloidosis after long-term dialysis treatment. PMID:18344065

  17. The relationships between self-assessed habitual physical activity and non-invasive measures of cardiac autonomic modulation in young healthy volunteers.

    PubMed

    Sandercock, Gavin R H; Hardy-Shepherd, Darren; Nunan, David; Brodie, David

    2008-09-01

    Heart rate variability estimates cardiac autonomic modulation, but the relationship between habitual physical activity and heart rate variability remains unclear. The aims of this study were to compare RR-interval and heart rate variability indices in individuals of different habitual physical activity levels, and examine the relationship between habitual physical activity and heart rate variability. Ninety-two healthy volunteers (47 men, 45 women; mean age 23.1 years, s = 2.1) were divided into tertiles according to the Baecke Questionnaire score. Standard heart rate variability indices were derived from 5-min resting RR-interval recordings with paced respiration (0.25 Hz). Between-group differences and the relationship between habitual physical activity and heart rate variability were assessed. More active participants (tertiles 2-3) had longer RR-intervals than those in tertile 1 (P < 0.05). Participants in tertile 2 had higher root mean squared differences of successive normal RR-intervals than those in tertile 1 and a higher standard deviation of normal RR-intervals than those in tertiles 1 and 3. There was a positive linear relationship between habitual activity and RR-interval. Differing RR-interval lengths were found in subgroups of young individuals according to level of habitual physical activity. More active individuals showed resting bradycardia without evidence of enhanced cardiac parasympathetic modulation. The mechanism linking habitual physical activity and RR-interval length appears to be independent of physiological mechanisms that can be measured by heart rate variability. PMID:18608846

  18. [Multiple cardiac rhabdomyoma associated to intrauterine death].

    PubMed

    Morales-Quispe, Jorge A; Espínola-Zavaleta, Nilda; Caballero-Caballero, Rocío; Brunner-Cruz, Guadalupe; Uribe Alcántara, Sergio

    2011-01-01

    Rhabdomyoma is the most common cardiac tumor detected during fetal life and childhood; nevertheless its incidence is very low. This is a histologically benign tumor, but in some cases may cause hemodynamic repercussion with date of low cardiac output, arrhythmias and exceptionally intrauterine death as occurred in our case, which was detected by obstetric ultrasound and fetal echocardiogram and corroborated by histological study. PMID:21975236

  19. Adaptive detection of missed text areas in OCR outputs: application to the automatic assessment of OCR quality in mass digitization projects

    NASA Astrophysics Data System (ADS)

    Ben Salah, Ahmed; Ragot, Nicolas; Paquet, Thierry

    2013-01-01

    The French National Library (BnF*) has launched many mass digitization projects in order to give access to its collection. The indexation of digital documents on Gallica (digital library of the BnF) is done through their textual content obtained thanks to service providers that use Optical Character Recognition softwares (OCR). OCR softwares have become increasingly complex systems composed of several subsystems dedicated to the analysis and the recognition of the elements in a page. However, the reliability of these systems is always an issue at stake. Indeed, in some cases, we can find errors in OCR outputs that occur because of an accumulation of several errors at different levels in the OCR process. One of the frequent errors in OCR outputs is the missed text components. The presence of such errors may lead to severe defects in digital libraries. In this paper, we investigate the detection of missed text components to control the OCR results from the collections of the French National Library. Our verification approach uses local information inside the pages based on Radon transform descriptors and Local Binary Patterns descriptors (LBP) coupled with OCR results to control their consistency. The experimental results show that our method detects 84.15% of the missed textual components, by comparing the OCR ALTO files outputs (produced by the service providers) to the images of the document.

  20. Power output measurement during treadmill cycling.

    PubMed

    Coleman, D A; Wiles, J D; Davison, R C R; Smith, M F; Swaine, I L

    2007-06-01

    The study aim was to consider the use of a motorised treadmill as a cycling ergometry system by assessing predicted and recorded power output values during treadmill cycling. Fourteen male cyclists completed repeated cycling trials on a motorised treadmill whilst riding their own bicycle fitted with a mobile ergometer. The speed, gradient and loading via an external pulley system were recorded during 20-s constant speed trials and used to estimate power output with an assumption about the contribution of rolling resistance. These values were then compared with mobile ergometer measurements. To assess the reliability of measured power output values, four repeated trials were conducted on each cyclist. During level cycling, the recorded power output was 257.2 +/- 99.3 W compared to the predicted power output of 258.2 +/- 99.9 W (p > 0.05). For graded cycling, there was no significant difference between measured and predicted power output, 268.8 +/- 109.8 W vs. 270.1 +/- 111.7 W, p > 0.05, SEE 1.2 %. The coefficient of variation for mobile ergometer power output measurements during repeated trials ranged from 1.5 % (95 % CI 1.2 - 2.0 %) to 1.8 % (95 % CI 1.5 - 2.4 %). These results indicate that treadmill cycling can be used as an ergometry system to assess power output in cyclists with acceptable accuracy. PMID:17497583

  1. Myocardial Dysfunction and Shock after Cardiac Arrest

    PubMed Central

    Jentzer, Jacob C.; Chonde, Meshe D.; Dezfulian, Cameron

    2015-01-01

    Postarrest myocardial dysfunction includes the development of low cardiac output or ventricular systolic or diastolic dysfunction after cardiac arrest. Impaired left ventricular systolic function is reported in nearly two-thirds of patients resuscitated after cardiac arrest. Hypotension and shock requiring vasopressor support are similarly common after cardiac arrest. Whereas shock requiring vasopressor support is consistently associated with an adverse outcome after cardiac arrest, the association between myocardial dysfunction and outcomes is less clear. Myocardial dysfunction and shock after cardiac arrest develop as the result of preexisting cardiac pathology with multiple superimposed insults from resuscitation. The pathophysiology involves cardiovascular ischemia/reperfusion injury and cardiovascular toxicity from excessive levels of inflammatory cytokine activation and catecholamines, among other contributing factors. Similar mechanisms occur in myocardial dysfunction after cardiopulmonary bypass, in sepsis, and in stress-induced cardiomyopathy. Hemodynamic stabilization after resuscitation from cardiac arrest involves restoration of preload, vasopressors to support arterial pressure, and inotropic support if needed to reverse the effects of myocardial dysfunction and improve systemic perfusion. Further research is needed to define the role of postarrest myocardial dysfunction on cardiac arrest outcomes and identify therapeutic strategies. PMID:26421284

  2. Robotic cardiac surgery: an anaesthetic challenge.

    PubMed

    Wang, Gang; Gao, Changqing

    2014-08-01

    Robotic cardiac surgery with the da Vinci robotic surgical system offers the benefits of a minimally invasive procedure, including a smaller incision and scar, reduced risk of infection, less pain and trauma, less bleeding and blood transfusion requirements, shorter hospital stay and decreased recovery time. Robotic cardiac surgery includes extracardiac and intracardiac procedures. Extracardiac procedures are often performed on a beating heart. Intracardiac procedures require the aid of peripheral cardiopulmonary bypass via a minithoracotomy. Robotic cardiac surgery, however, poses challenges to the anaesthetist, as the obligatory one-lung ventilation (OLV) and CO2 insufflation may reduce cardiac output and increase pulmonary vascular resistance, potentially resulting in hypoxaemia and haemodynamic compromise. In addition, surgery requires appropriate positioning of specialised cannulae such as an endopulmonary vent, endocoronary sinus catheter, and endoaortic clamp catheter under the guidance of transoesophageal echocardiography. Therefore, cardiac anaesthetists should have a working knowledge of these systems, OLV and haemodynamic support. PMID:24958894

  3. Estimates of embodied global energy and air-emission intensities of Japanese products for building a Japanese input-output life cycle assessment database with a global system boundary.

    PubMed

    Nansai, Keisuke; Kondo, Yasushi; Kagawa, Shigemi; Suh, Sangwon; Nakajima, Kenichi; Inaba, Rokuta; Tohno, Susumu

    2012-08-21

    To build a life cycle assessment (LCA) database of Japanese products embracing their global supply chains in a manner requiring lower time and labor burdens, this study estimates the intensity of embodied global environmental burden for commodities produced in Japan. The intensity of embodied global environmental burden is a measure of the environmental burden generated globally by unit production of the commodity and can be used as life cycle inventory data in LCA. The calculation employs an input-output LCA method with a global link input-output model that defines a global system boundary grounded in a simplified multiregional input-output framework. As results, the intensities of embodied global environmental burden for 406 Japanese commodities are determined in terms of energy consumption, greenhouse-gas emissions (carbon dioxide, methane, nitrous oxide, perfluorocarbons, hydrofluorocarbons, sulfur hexafluoride, and their summation), and air-pollutant emissions (nitrogen oxide and sulfur oxide). The uncertainties in the intensities of embodied global environmental burden attributable to the simplified structure of the global link input-output model are quantified using Monte Carlo simulation. In addition, by analyzing the structure of the embodied global greenhouse-gas intensities we characterize Japanese commodities in the context of LCA embracing global supply chains. PMID:22881452

  4. Estimates of Embodied Global Energy and Air-Emission Intensities of Japanese Products for Building a Japanese Input–Output Life Cycle Assessment Database with a Global System Boundary

    PubMed Central

    2012-01-01

    To build a life cycle assessment (LCA) database of Japanese products embracing their global supply chains in a manner requiring lower time and labor burdens, this study estimates the intensity of embodied global environmental burden for commodities produced in Japan. The intensity of embodied global environmental burden is a measure of the environmental burden generated globally by unit production of the commodity and can be used as life cycle inventory data in LCA. The calculation employs an input–output LCA method with a global link input–output model that defines a global system boundary grounded in a simplified multiregional input–output framework. As results, the intensities of embodied global environmental burden for 406 Japanese commodities are determined in terms of energy consumption, greenhouse-gas emissions (carbon dioxide, methane, nitrous oxide, perfluorocarbons, hydrofluorocarbons, sulfur hexafluoride, and their summation), and air-pollutant emissions (nitrogen oxide and sulfur oxide). The uncertainties in the intensities of embodied global environmental burden attributable to the simplified structure of the global link input–output model are quantified using Monte Carlo simulation. In addition, by analyzing the structure of the embodied global greenhouse-gas intensities we characterize Japanese commodities in the context of LCA embracing global supply chains. PMID:22881452

  5. Microdialysis Assessment of Cerebral Perfusion during Cardiac Arrest, Extracorporeal Life Support and Cardiopulmonary Resuscitation in Rats – A Pilot Trial

    PubMed Central

    Schober, Andreas; Warenits, Alexandra M.; Testori, Christoph; Weihs, Wolfgang; Hosmann, Arthur; Högler, Sandra; Sterz, Fritz; Janata, Andreas; Scherer, Thomas; Magnet, Ingrid A. M.; Ettl, Florian; Laggner, Anton N.; Herkner, Harald; Zeitlinger, Markus

    2016-01-01

    Cerebral metabolic alterations during cardiac arrest, cardiopulmonary resuscitation (CPR) and extracorporeal cardiopulmonary life support (ECLS) are poorly explored. Markers are needed for a more personalized resuscitation and post—resuscitation care. Aim of this study was to investigate early metabolic changes in the hippocampal CA1 region during ventricular fibrillation cardiac arrest (VF-CA) and ECLS versus conventional CPR. Male Sprague-Dawley rats (350g) underwent 8min untreated VF-CA followed by ECLS (n = 8; bloodflow 100ml/kg), mechanical CPR (n = 18; 200/min) until return of spontaneous circulation (ROSC). Shams (n = 2) were included. Glucose, glutamate and lactate/pyruvate ratio were compared between treatment groups and animals with and without ROSC. Ten animals (39%) achieved ROSC (ECLS 5/8 vs. CPR 5/18; OR 4,3;CI:0.7–25;p = 0.189). During VF-CA central nervous glucose decreased (0.32±0.1mmol/l to 0.04±0.01mmol/l; p<0.001) and showed a significant rise (0.53±0.1;p<0.001) after resuscitation. Lactate/pyruvate (L/P) ratio showed a 5fold increase (31 to 164; p<0.001; maximum 8min post ROSC). Glutamate showed a 3.5-fold increase to (2.06±1.5 to 7.12±5.1μmol/L; p<0.001) after CA. All parameters normalized after ROSC with no significant differences between ECLS and CPR. Metabolic changes during ischemia and resuscitation can be displayed by cerebral microdialysis in our VF-CA CPR and ECLS rat model. We found similar microdialysate concentrations and patterns of normalization in both resuscitation methods used. Institutional Protocol Number: GZ0064.11/3b/2011 PMID:27175905

  6. Assessment of global cardiac uptake of Radiolabeled Iron Oxide Nanoparticles in Apolipoprotein E-Deficient Mice: implications for imaging cardiovascular inflammation

    PubMed Central

    de Barros, André Luís Branco; Chacko, Ann-Marie; Mikitsh, John L.; Zaki, Ajlan Al; Salavati, Ali; Saboury, Babak; Tsourkas, Andrew; Alavi, Abass

    2014-01-01

    Purpose Atherosclerosis is a leading cause of death in industrialized countries and is characterized by the accumulation of lipids and inflammatory cells, including macrophages, in blood vessel walls. Therefore, the ability to image macrophages could help identify plaques that are precursors of acute thrombotic events. Previous research has shown that long-circulating, nanoparticles could be used to detect macrophages within atherosclerotic plaques of the aorta. By conducting this study, we investigated whether global cardiac uptake of radiolabeled nanoparticles could allow assessment of total macrophage burden in the coronary arteries. Procedures Dextran-coated Iron Oxide Nanoparticles (IONPs) were labeled with iodine-125 via Bolton-Hunter (SHPP) method. IONPs were characterized by means of dynamic light scattering and transmission electronic microscopy. Biodistribution studies were performed in healthy and atherosclerotic mice. Additionally, digital autoradiography of hearts from both healthy and atherosclerotic mice was performed to assess regional and global atherosclerotic burden. Results The [125I]IONPs exhibited high radiolabel stability and long blood circulation, which eventually led to high heart uptake in apoE −/− mice when compared with healthy controls. Furthermore, digital autoradiography showed substantially enhanced emission of signals from the hearts of atherosclerotic mice, while no or minimal cardiac signals were detected in healthy mice. Conclusions This preparation showed adequate physical-chemical properties for in vivo studies, such as small size (~30 nm), good radiolabel stability, and long circulation time. There was also significant accumulation in the heart of apoE−/− mice compared with that of healthy control animals. These findings suggest that radiolabeled dextran-coated iron oxide nanoparticles may have potential to become a useful tool to detect macrophages in the atherosclerosis plaques of coronary arteries; however, these preliminary findings should be confirmed by further studies in a larger scale in various atherosclerosis models. PMID:24297372

  7. Assessment of RCM output from the ENSEMBLES RT3 project in AMMA-region: focus on Senegal actual climate reproduction and effects on simulated crop yields

    NASA Astrophysics Data System (ADS)

    Oettli, Pascal; Sultan, Benjamin; Baron, Christian; Vrac, Mathieu

    2010-05-01

    In West-Africa countries, most economies and people depend on rainfed agriculture. In this area, rainfall is highly variable and, from the period 1931-1960 to 1968-1990, the annual rainfall has decreased 15 to 40%. Since the mid 1990's, an increase in rainfall is detected, but only to reach the level of 1970's rainfall. The aim of this study is to determine if large-scale fields, interpolated at local-scale are able (i) to reproduce observed climate at station and (ii) to simulate observed crop yields. Another objective of this study is to see if a combination of dynamical and statistical downscaling methods is useful to correct biases due to scale change. For that, we use data from some synoptic stations in Senegal and simulated data provided by the European project ENSEMBLES. Among research themes (RT) of this project, one (RT3) had the responsibility for providing improved climate model tools developed in the context of regional climate models (RCMs), at spatial scales of 50km at AMMA-region. RT3 provides 15-year experiments over West Africa driven by the ERA-INTERIM reanalysis of the ECMWF. A statistical method (CDF-transform), developed to generate local cumulative distribution functions of surface climate variables from large-scale fields is used to correct biases in RCM output, due to large-scale information basically interpolated at local-scale. In the present study, a deterministic crop model, SARRA-H, is used to simulate sorghum yields for the actual period, at local scale. This crop model simulates yield attainable under water-limited conditions by simulating the soil water balance, potential and actual evapotranspiration, phenology, potential and water-limited carbon assimilation, and biomass partitioning. SARRA-H model is driven by 4 meteorological datasets, at synoptic station scale: - observations, - ERA-INTERIM, - original RCM output, - corrected RCM output.

  8. Bayesian Sensitivity Analysis of a Cardiac Cell Model Using a Gaussian Process Emulator

    PubMed Central

    Chang, Eugene T Y; Strong, Mark; Clayton, Richard H

    2015-01-01

    Models of electrical activity in cardiac cells have become important research tools as they can provide a quantitative description of detailed and integrative physiology. However, cardiac cell models have many parameters, and how uncertainties in these parameters affect the model output is difficult to assess without undertaking large numbers of model runs. In this study we show that a surrogate statistical model of a cardiac cell model (the Luo-Rudy 1991 model) can be built using Gaussian process (GP) emulators. Using this approach we examined how eight outputs describing the action potential shape and action potential duration restitution depend on six inputs, which we selected to be the maximum conductances in the Luo-Rudy 1991 model. We found that the GP emulators could be fitted to a small number of model runs, and behaved as would be expected based on the underlying physiology that the model represents. We have shown that an emulator approach is a powerful tool for uncertainty and sensitivity analysis in cardiac cell models. PMID:26114610

  9. Cardiac optogenetics

    PubMed Central

    2013-01-01

    Optogenetics is an emerging technology for optical interrogation and control of biological function with high specificity and high spatiotemporal resolution. Mammalian cells and tissues can be sensitized to respond to light by a relatively simple and well-tolerated genetic modification using microbial opsins (light-gated ion channels and pumps). These can achieve fast and specific excitatory or inhibitory response, offering distinct advantages over traditional pharmacological or electrical means of perturbation. Since the first demonstrations of utility in mammalian cells (neurons) in 2005, optogenetics has spurred immense research activity and has inspired numerous applications for dissection of neural circuitry and understanding of brain function in health and disease, applications ranging from in vitro to work in behaving animals. Only recently (since 2010), the field has extended to cardiac applications with less than a dozen publications to date. In consideration of the early phase of work on cardiac optogenetics and the impact of the technique in understanding another excitable tissue, the brain, this review is largely a perspective of possibilities in the heart. It covers the basic principles of operation of light-sensitive ion channels and pumps, the available tools and ongoing efforts in optimizing them, overview of neuroscience use, as well as cardiac-specific questions of implementation and ideas for best use of this emerging technology in the heart. PMID:23457014

  10. Cardiac Surgery

    PubMed Central

    Weisse, Allen B.

    2011-01-01

    Well into the first decades of the 20th century, medical opinion held that any surgical attempts to treat heart disease were not only misguided, but unethical. Despite such reservations, innovative surgeons showed that heart wounds could be successfully repaired. Then, extracardiac procedures were performed to correct patent ductus arteriosus, coarctation of the aorta, and tetralogy of Fallot. Direct surgery on the heart was accomplished with closed commissurotomy for mitral stenosis. The introduction of the heart-lung machine and cardiopulmonary bypass enabled the surgical treatment of other congenital and acquired heart diseases. Advances in aortic surgery paralleled these successes. The development of coronary artery bypass grafting greatly aided the treatment of coronary heart disease. Cardiac transplantation, attempts to use the total artificial heart, and the application of ventricular assist devices have brought us to the present day. Although progress in the field of cardiovascular surgery appears to have slowed when compared with the halcyon times of the past, substantial challenges still face cardiac surgeons. It can only be hoped that sufficient resources and incentive can carry the triumphs of the 20th century into the 21st. This review covers past developments and future opportunities in cardiac surgery. PMID:22163121

  11. Comparison of Two Pain Assessment Tools, “Facial Expression” and “Critical Care Pain Observation Tool” in Intubated Patients After Cardiac Surgery

    PubMed Central

    Kiavar, Majid; Azarfarin, Rasoul; Totonchi, Ziae; Tavakoli, Fatemeh; Alizadehasl, Azin; Teymouri, Mitra

    2016-01-01

    Background: Critical-care patients are at higher risk of untreated pain, because they are often unable to communicate owing to altered mental status, tracheal intubation and sedation. Objectives: This study compared two pain assessment tools on tracheal intubated critically ill patients in a cardiac post-anesthesia care unit, who were unable to communicate verbally. The studied tools were “critical-care pain observation tool (CPOT)” and “facial expression (FE)”. Patients and Methods: This was a prospective study based on diagnostic test evaluation. A sample of 91 intubated patients was selected from cardiac post-anesthesia care unit. Collected data were demographic characteristics, vital signs, FE and CPOT tools’ scale. Pain was assessed with CPOT and FE scores five times. The first assessment was performed in at least 3 hours after admission of patients to ICU. Then, the pain intensity was reassessed every 30 minutes. In addition, blood pressure, heart rate, respiratory rate and oxygen saturation were measured simultaneously. Results: At the first period, the frequency of “severe” pain intensity using the CPOT was 58.2% and with the FE tool was 67% (P = 0.001). Both tools demonstrated reduction in severity of pain on second and third assessment times. Significantly increasing level of pain and blood pressure due to nursing painful procedures (endo-tracheal suctioning, changing patient’s position, etc.), were obtained by CPOT in fourth assessment. FE was not able to detect such important findings (κ = 0.249). In the fifth step, pain intensity was reduced. The most agreement between the two tools was observed when the reported pain was “severe” (κ = 0.787, P < 0.001) and “mild” (κ = 0.851, P < 0.001). Conclusions: The sensitivity of CPOT was higher for detection and evaluation of pain in intubated postoperative patients compared with “Facial Expression”. Best agreement between these tools was observed in two extremes of pain intensity.

  12. Cardiac mechanics: Physiological, clinical, and mathematical considerations

    NASA Technical Reports Server (NTRS)

    Mirsky, I. (Editor); Ghista, D. N.; Sandler, H.

    1974-01-01

    Recent studies concerning the basic physiological and biochemical principles underlying cardiac muscle contraction, methods for the assessment of cardiac function in the clinical situation, and mathematical approaches to cardiac mechanics are presented. Some of the topics covered include: cardiac ultrastructure and function in the normal and failing heart, myocardial energetics, clinical applications of angiocardiography, use of echocardiography for evaluating cardiac performance, systolic time intervals in the noninvasive assessment of left ventricular performance in man, evaluation of passive elastic stiffness for the left ventricle and isolated heart muscle, a conceptual model of myocardial infarction and cardiogenic shock, application of Huxley's sliding-filament theory to the mechanics of normal and hypertrophied cardiac muscle, and a rheological modeling of the intact left ventricle. Individual items are announced in this issue.

  13. Cardiac cone-beam CT

    SciTech Connect

    Manzke, Robert . E-mail: robert.manzke@philips.com

    2005-10-15

    This doctoral thesis addresses imaging of the heart with retrospectively gated helical cone-beam computed tomography (CT). A thorough review of the CT reconstruction literature is presented in combination with a historic overview of cardiac CT imaging and a brief introduction to other cardiac imaging modalities. The thesis includes a comprehensive chapter about the theory of CT reconstruction, familiarizing the reader with the problem of cone-beam reconstruction. The anatomic and dynamic properties of the heart are outlined and techniques to derive the gating information are reviewed. With the extended cardiac reconstruction (ECR) framework, a new approach is presented for the heart-rate-adaptive gated helical cardiac cone-beam CT reconstruction. Reconstruction assessment criteria such as the temporal resolution, the homogeneity in terms of the cardiac phase, and the smoothness at cycle-to-cycle transitions are developed. Several reconstruction optimization approaches are described: An approach for the heart-rate-adaptive optimization of the temporal resolution is presented. Streak artifacts at cycle-to-cycle transitions can be minimized by using an improved cardiac weighting scheme. The optimal quiescent cardiac phase for the reconstruction can be determined automatically with the motion map technique. Results for all optimization procedures applied to ECR are presented and discussed based on patient and phantom data. The ECR algorithm is analyzed for larger detector arrays of future cone-beam systems throughout an extensive simulation study based on a four-dimensional cardiac CT phantom. The results of the scientific work are summarized and an outlook proposing future directions is given. The presented thesis is available for public download at www.cardiac-ct.net.

  14. Partial scan artifact reduction (PSAR) for the assessment of cardiac perfusion in dynamic phase-correlated CT

    SciTech Connect

    Stenner, Philip; Schmidt, Bernhard; Bruder, Herbert; Allmendinger, Thomas; Haberland, Ulrike; Flohr, Thomas; Kachelriess, Marc

    2009-12-15

    Purpose: Cardiac CT achieves its high temporal resolution by lowering the scan range from 2{pi} to {pi} plus fan angle (partial scan). This, however, introduces CT-value variations, depending on the angular position of the {pi} range. These partial scan artifacts are of the order of a few HU and prevent the quantitative evaluation of perfusion measurements. The authors present the new algorithm partial scan artifact reduction (PSAR) that corrects a dynamic phase-correlated scan without a priori information. Methods: In general, a full scan does not suffer from partial scan artifacts since all projections in [0, 2{pi}] contribute to the data. To maintain the optimum temporal resolution and the phase correlation, PSAR creates an artificial full scan p{sub n}{sup AF} by projectionwise averaging a set of neighboring partial scans p{sub n}{sup P} from the same perfusion examination (typically N{approx_equal}30 phase-correlated partial scans distributed over 20 s and n=1,...,N). Corresponding to the angular range of each partial scan, the authors extract virtual partial scans p{sub n}{sup V} from the artificial full scan p{sub n}{sup AF}. A standard reconstruction yields the corresponding images f{sub n}{sup P}, f{sub n}{sup AF}, and f{sub n}{sup V}. Subtracting the virtual partial scan image f{sub n}{sup V} from the artificial full scan image f{sub n}{sup AF} yields an artifact image that can be used to correct the original partial scan image: f{sub n}{sup C}=f{sub n}{sup P}-f{sub n}{sup V}+f{sub n}{sup AF}, where f{sub n}{sup C} is the corrected image. Results: The authors evaluated the effects of scattered radiation on the partial scan artifacts using simulated and measured water phantoms and found a strong correlation. The PSAR algorithm has been validated with a simulated semianthropomorphic heart phantom and with measurements of a dynamic biological perfusion phantom. For the stationary phantoms, real full scans have been performed to provide theoretical reference values. The improvement in the root mean square errors between the full and the partial scans with respect to the errors between the full and the corrected scans is up to 54% for the simulations and 90% for the measurements. Conclusions: The phase-correlated data now appear accurate enough for a quantitative analysis of cardiac perfusion.

  15. Diodes stabilize LED output

    NASA Technical Reports Server (NTRS)

    Deters, R. A.

    1977-01-01

    Small-signal diodes are placed in series with light-emitting diodes (LED's) to stabilize LED output against temperature fluctuations. Simple inexpensive method compensates for thermal fluctuations over a broad temperature range. Requiring few components, technique is particularly useful where circuit-board space is limited.

  16. Effects of exercise rehabilitation on cardiac electrical instability assessed by T-wave alternans during ambulatory electrocardiogram monitoring in coronary artery disease patients without and with diabetes mellitus.

    PubMed

    Kenttä, Tuomas; Tulppo, Mikko P; Nearing, Bruce D; Karjalainen, Jaana J; Hautala, Arto J; Kiviniemi, Antti M; Huikuri, Heikki V; Verrier, Richard L

    2014-09-15

    Effects of exercise rehabilitation on electrocardiographic markers of risk for sudden cardiac death have not been adequately studied. We examined effects of controlled exercise training on T-wave alternans (TWA) in 24-hour ambulatory electrocardiogram recordings in patients with stable coronary artery disease (CAD) without and with type 2 diabetes mellitus (DM). Consecutive patients with angiographically confirmed CAD were recruited to join the ARTEMIS (Innovation to Reduce Cardiovascular Complications of Diabetes at the Intersection) study. Exercise (n = 65) and control groups (n = 65) were matched on age, sex, DM, and previous myocardial infarction. Ambulatory electrocardiograms were recorded before and after a 2-year training period. TWA was assessed using time domain-modified moving average method by an investigator blinded to patients' clinical status. Average TWA values decreased in the rehabilitation group but not in control patients (rehabilitation [mean ± SEM]: 52.8 ± 1.7 μV vs 48.7 ± 1.5 μV, p <0.001; control: 53.7 ± 1.7 μV vs 54.3 ± 1.6 μV, p = 0.746). Changes in TWA differed between the groups (rehabilitation: -4.1 ± 1.2 μV vs controls: +0.6 ± 1.1 μV, p = 0.005). In CAD + DM patients, 50% (n = 9) of the 18 positive TWA cases were converted with exercise versus 10% (n = 2 of 20) of controls (p = 0.020). In CAD patients, 30% (n = 8 of 27) of positive TWA cases were converted with exercise versus 4% (n = 1 of 28) of controls (p = 0.012). In conclusion, this is the first report of the effectiveness of exercise rehabilitation to reduce TWA, a marker of sudden cardiac death risk, in patients with stable CAD. PMID:25107578

  17. The China Patient-Centred Evaluative Assessment of Cardiac Events (China PEACE)-Prospective Study of 3-Vessel Disease: rationale and design

    PubMed Central

    Rao, Chenfei; Bongiovanni, Tasce; Li, Xi; Gao, Huawei; Zhang, Heng; Li, Jing; Zhao, Yan; Yuan, Xin; Hua, Kun; Hu, Shengshou; Krumholz, Harlan M; Jiang, Lixin; Zheng, Zhe

    2016-01-01

    Introduction Complex coronary artery disease (left main and three-vessel disease) carries high risks of adverse events and cost burden. However, in China, little is known about which patients are directed toward which treatment strategies and what outcomes are being achieved. Methods and analysis Using the China PEACE (Patient-centered Evaluative Assessment of Cardiac Events) research network, this prospective study of three-Vessel Disease, the China PEACE-3VD study, has a plan to consecutively register over 4000 patients with a diagnosis of 3VD and/or left-main disease by elective coronary angiography at 24 large cardiovascular centres in China. We centrally conducted medical record abstraction and SYNTAX Score calculation for all registered patients. The sites invited patients to the prospective cohort, and conducted 1-year follow-up on major events, including cardiac events, symptoms, secondary prevention and quality of life. The estimated entire sample size of eligible patients of 4000 was determined based on both feasibility and consideration of adequate statistical precision for describing the treatment decisions, guidelines adherence and appropriateness of treatment for patients with complex coronary artery diseases. The study is designed to investigate patient, clinician and hospital factors associated with each treatment strategy (percutaneous coronary intervention, coronary artery bypass grafting or medical therapy) as well as appropriateness of treatment choice, current guideline compliance and patient-reported outcomes for patients with complex coronary artery disease in large cardiovascular centres in China, as a foundation for enhanced knowledge in the field and to assist quality improvement initiatives. Ethics and dissemination The study protocol was approved by the ethics committee at the China National Center for Cardiovascular Diseases. Findings will be shared with participating hospitals, policymakers and the academic community, to promote quality monitoring, quality improvement and the efficient allocation, and use of coronary revascularisation procedures in China. Trial registration number NCT01625312; Pre-results PMID:26880670

  18. Time course of circulatory and metabolic recovery of cat brain after cardiac arrest assessed by perfusion- and diffusion-weighted imaging and MR-spectroscopy.

    PubMed

    Krep, Henning; Bttiger, Bernd W; Bock, Christian; Kerskens, Christian M; Radermacher, Bernd; Fischer, Matthias; Hoehn, Mathias; Hossmann, Konstantin Alexander

    2003-09-01

    Brain recovery after cardiac arrest (CA) was assessed in cats using arterial spin tagging perfusion-weighted imaging (PWI), diffusion-weighted imaging (DWI), and 1H-spectroscopy (1H-MRS). Cerebral reperfusion and metabolic recovery was monitored in the cortex and in basal ganglia for 6 h after cardiopulmonary resuscitation (CPR). Furthermore, the effects of an hypertonic/hyperoncotic solution (7.5% NaCl/6% hydroxyl ethyl starch, HES) and a tissue-type plasminogen activator (TPA), applied during CPR, were assessed on brain recovery. CA and CPR were carried out in the MR scanner by remote control. CA for 15-20 min was induced by electrical fibrillation of the heart, followed by CPR using a pneumatic vest. PWI after successful CPR revealed initial cerebral hyperperfusion followed by delayed hypoperfusion. Initial cerebral recirculation was improved after osmotic treatment. Osmotic and thrombolytic therapy were ineffective in ameliorating delayed hypoperfusion. Calculation of the apparent diffusion coefficient (ADC) from DWI demonstrated complete recovery of ion and water homeostasis in all animals. 1H-MRS measurements of lactate suggested an extended preservation of post-ischaemic anaerobic metabolism after TPA treatment. The combination of noninvasive MR techniques is a powerful tool for the evaluation of therapeutical strategies on circulatory and metabolic cerebral recovery after experimental cerebral ischaemia. PMID:12969612

  19. Cardiac Vagal Regulation and Early Peer Status

    ERIC Educational Resources Information Center

    Graziano, Paulo A.; Keane, Susan P.; Calkins, Susan D.

    2007-01-01

    A sample of 341 5 1/2-year-old children participating in an ongoing longitudinal study was the focus of a study on the relation between cardiac vagal regulation and peer status. To assess cardiac vagal regulation, resting measures of respiratory sinus arrhythmia (RSA) and RSA change (suppression) to 3 cognitively and emotionally challenging tasks…

  20. An updated model for nitrate uptake modelling in plants. II. Assessment of active root involvement in nitrate uptake based on integrated root system age: measured versus modelled outputs

    PubMed Central

    Malagoli, Philippe; Le Deunff, Erwan

    2014-01-01

    Background and Aims An updated version of a mechanistic structural–functional model was developed to predict nitrogen (N) uptake throughout the growth cycle by a crop of winter oilseed rape, Brassica napus, grown under field conditions. Methods The functional component of the model derives from a revisited conceptual framework that combines the thermodynamic Flow–Force interpretation of nitrate uptake isotherms and environmental and in planta effects on nitrate influx. Estimation of the root biomass (structural component) is based upon a combination of root mapping along the soil depth profile in the field and a relationship between the specific root length and external nitrate concentration. The root biomass contributing actively to N uptake was determined by introduction of an integrated root system age that allows assignment of a root absorption capacity at a specific age of the root. Key Results Simulations were well matched to measured data of N taken up under field conditions for three levels of N fertilization. The model outputs indicated that the two topsoil layers (0–30 and 30–60 cm) contained 75–88 % of the total root length and biomass, and accounted for 90–95 % of N taken up at harvest. Conclusions This conceptual framework provides a model of nitrate uptake that is able to respond to external nitrate fluctuations at both functional and structural levels. PMID:24709791

  1. An updated model for nitrate uptake modelling in plants. II. Assessment of active root involvement in nitrate uptake based on integrated root system age: measured versus modelled outputs.

    PubMed

    Malagoli, Philippe; Le Deunff, Erwan

    2014-05-01

    Background and Aims An updated version of a mechanistic structural-functional model was developed to predict nitrogen (N) uptake throughout the growth cycle by a crop of winter oilseed rape, Brassica napus, grown under field conditions. Methods The functional component of the model derives from a revisited conceptual framework that combines the thermodynamic Flow-Force interpretation of nitrate uptake isotherms and environmental and in planta effects on nitrate influx. Estimation of the root biomass (structural component) is based upon a combination of root mapping along the soil depth profile in the field and a relationship between the specific root length and external nitrate concentration. The root biomass contributing actively to N uptake was determined by introduction of an integrated root system age that allows assignment of a root absorption capacity at a specific age of the root. Key Results Simulations were well matched to measured data of N taken up under field conditions for three levels of N fertilization. The model outputs indicated that the two topsoil layers (0-30 and 30-60 cm) contained 75-88 % of the total root length and biomass, and accounted for 90-95 % of N taken up at harvest. Conclusions This conceptual framework provides a model of nitrate uptake that is able to respond to external nitrate fluctuations at both functional and structural levels. PMID:24709791

  2. [Progress on cardiac imaging techniques].

    PubMed

    Vivancos-Delgado, Ricardo; Gómez de Diego, José J; Aguilar-Torres, Río; Forteza-Alberti, José F

    2011-01-01

    The development of a noninvasive diagnostic test follows a typical timeline: description, enthusiasm, clinical assessment and application, and epidemiological study. However, for techniques such as echocardiography that are widely available, have no harmful effects and are inexpensive, clinical applications may become widespread before they have been evaluated. Real progress is being made with the use of new methodologies, such as myocardial deformation echocardiography and three-dimensional echocardiography. Three-dimensional transesophageal echocardiography has returned echocardiography to its place at the center of modern cardiac diagnosis after it had been displaced in recent years by cardiac multislice CT and cardiac magnetic resonance. However, the new radiological techniques that have helped to reduce radiation exposure to patients and that have improved image acquisition could restore CT to the heart of general cardiac diagnosis. At the moment, it is not possible to displace the echocardiography from its central role in cardiac imaging. This article contains a review of the most important publications on echocardiography, magnetic resonance imaging and cardiac CT that have appeared recently in cardiology journals, mainly during 2010. PMID:21276488

  3. Climate Model Output Rewriter

    Energy Science and Technology Software Center (ESTSC)

    2004-06-21

    CMOR comprises a set of FORTRAN 90 dunctions that can be used to produce CF-compliant netCDF files. The structure of the files created by CMOR and the metadata they contain fulfill the requirements of many of the climate community’s standard model experiments (which are referred to here as "MIPS", which stands for "model intercomparison project", including, for example, AMIP, CMIP, CFMIP, PMIP, APE, and IPCC scenario runs), CMOR was not designed to serve as anmore » all-purpose wfiter of CF-compliant netCDF files, but simply to reduce the effort required to prepare and manage MIP data. Although MIPs encourage systematic analysis of results across models, this is only easy to do if the model output is written in a common format with files structured similarly and with sufficient metadata uniformly stored according to a common standard. Individual modeling groups store their data in different ways. but if a group can read its own data with FORTRAN, then it should easily be able to transform the data, using CMOR, into the common format required by the MIPs, The adoption of CMOR as a standard code for exchanging climate data will facilitate participation in MIPs because after learning how to satisfy the output requirements of one MIP, it will be easy to prepare output for the other MIPs.« less

  4. An electrophysiological study of the accessory olfactory bulb in the rabbit--II. Input-output relations as assessed from analysis of intra- and extracellular unit recordings.

    PubMed

    Reinhardt, W; MacLeod, N K; Ladewig, J; Ellendorff, F

    1983-09-01

    The input-output relations of the rabbit accessory olfactory bulb were studied by intra- and extracellular single unit recordings following electrical stimulation of the vomeronasal nerves, the lateral olfactory tract and the corticomedial amygdala. Cellular activity of accessory bulb mitral cells evoked by stimulation of the vomeronasal nerves consisted of a brief excitation with a latency of 16 ms. This initial response was followed by a period of reduced firing probability which was due to an inhibitory postsynaptic potential. In many cases this secondary response was followed by a second excitatory postsynaptic potential on which action potentials were generated at higher stimulus intensities. Deeper cells in the granule cell layer responded with a long latency, long duration, excitation, often consisting of bursts of 2-3 spikes. The majority of mitral cells were antidromically invaded by amygdala stimulation. The latencies of the antidromic spikes showed a wide range of variation (12-80 ms). Due to this great variation in antidromic latency the inhibitory postsynaptic potential following the antidromic action potential was rather modest but prolonged in duration. In many cases the onset of the inhibitory postsynaptic potential preceded the antidromic response. The majority of cells did not respond to lateral olfactory tract stimulation. Only 10% of the tested cells were invaded antidromically by stimulation at this site. These neurons were also driven antidromically by amygdala stimulation. We conclude that, although the physiological characteristics of mitral cells of the main and accessory olfactory bulb are very similar, there are important differences. The efferent fibres of the accessory bulb conduct at very slow and variable rates and project directly to the corticomedial amygdala. PMID:6646419

  5. The aging myostatin null phenotype: reduced adiposity, cardiac hypertrophy, enhanced cardiac stress response, and sexual dimorphism.

    PubMed

    Jackson, Melissa F; Luong, Dung; Vang, Dor Dor; Garikipati, Dilip K; Stanton, James B; Nelson, O Lynne; Rodgers, Buel D

    2012-06-01

    The natural aging process results in the physiological decline of multiple tissues and organ systems. Changes commonly occur with middle age and include decreased skeletal muscle mass, bone mineral density, cardiac output, and insulin sensitivity, and increased adiposity, all of which can contribute to the onset of sarcopenia, osteoporosis, heart failure, or type 2 diabetes. Recent studies suggest that myostatin may influence many of these systems. We therefore sought to determine whether they are affected by aging, especially in 'middle-aged' Mstn-/- mice (12-20 months old (m.o.)). Although body weights were similar in wild-type (WT) and Mstn-/- mice, lean fat-free mass and skeletal muscles composed of predominantly type I, II, and mixed fibers were significantly heavier in Mstn-/- mice. These differences were accompanied by lower total adiposity, especially in female mice, white and brown fat pad weights, and adipocyte size. Hearts were heavier in Mstn-/- mice across a large age range (3-24 m.o.) and exhibited signs of dilated cardiomyopathy at rest, which include lower strain measurements compared with WT myocardium. However, Mstn-/- mice responded better to isoproterenol stress tests with greater increases in fractional shortening and ejection fraction-differences that were again more apparent in females and which are consistent with physiological cardiac hypertrophy. Spleens and kidneys were also smaller, although histologically normal, in Mstn-/- mice. These data together suggest that attenuating myostatin could potentially prevent or possibly treat pathological conditions that develop with age. Additional studies are nevertheless needed to definitively assess potential risks to cardiac function. PMID:22431133

  6. [Cardiac surgery in the aged].

    PubMed

    Asano, K

    1988-01-01

    One hundred and seven patients aged greater than or equal to 60 years with cardiac surgery were reviewed. These patients underwent open heart surgery at University Hospital of Tokyo and JR Tokyo General Hospital during 1981 to 1987. Prevalence of the elderly with 60 years or older in all patients with cardiac surgery increased 4.1% to 20% during these seven years. Surgery for ischemic heart disease has become more common. There were less number of cases with valvular heart disease referred for surgery, but, not a few cases with calcified aortic valve or floppy mitral valve had valve replacement. Operative results were as follows: Hospital death was 6/107 patients (5.6%) and three patients died after discharge. This group of old patients was occasionally associated (14/107, 13%) with a variety of diseases including bronchial asthma, diabetes mellitus, and other atherosclerotic lesion or liver dysfunction. Valvular heart disease was not rarely complicated with ischemic heart disease. Postoperative complications were mainly due to renal failure, respiratory failure or low output syndrome, possibly related to associated disease. Intra-aortic balloon pumping was performed in seven of 107 patients, four of whom eventually died. In conclusion, there is a relatively high risk in cardiac surgery in old aged patients with associated diseases. We have to manage carefully old patients to avoid major postoperative complications including cardiac, respiratory and renal events. Much more old patients will have open heart surgery in the future. PMID:3274213

  7. An electricity-focused economic input-output model: Life-cycle assessment and policy implications of future electricity generation scenarios

    NASA Astrophysics Data System (ADS)

    Marriott, Joe

    The electricity industry is extremely important to both our economy and our environment. We would like to be able to examine the economic, environmental and policy implications of both future electricity scenarios which include advanced generation technologies such as gasified coal, and of the products and processes which will use them, along with the interaction of this industry with the rest of the economy. This work builds upon an existing economic input-output framework, by adding detail about the electricity industry, specifically by differentiating among the various functions of the sector, and the different means of generating power. The mix of electricity consumed at any stage in the life-cycle of a product, process or industrial sector has a significant effect on the associated inventory of emissions. Fossil fuel or nuclear generators, large-scale hydroelectric, and renewable options such as geothermal, wind and solar each have a unique set of issues---both in the production of electricity at the plant and throughout the supply chain. Decision makers need better information regarding the environmental and economic impact of the electricity industry, including full supply chain details---the interaction of the electricity industry with the other 500 sectors of the economy. A systematic method for creating updated state level and sector generation mixes is developed. The results show that most sector mixes are very close to the U.S. average due to geographic dispersion of industries, but that some sectors are different, and they tend to be important raw material extraction or primary manufacturing industries. We then build a flexible framework for creating new sectors, supply chains and emission factors for the generation, transmission and distribution portions of the electricity industry. We look at scenarios of the present and future, for electricity and for particular products, and develop results which show environmental impacts split up by generation type, and with full supply chain detail. For analyses of the current electricity system and products, economic and environmental results match well with external verification sources, but for analyses of the future, there is significant uncertainty.

  8. Heart rate variability as a measure of autonomic regulation of cardiac activity for assessing stress and welfare in farm animals -- a review.

    PubMed

    von Borell, Eberhard; Langbein, Jan; Després, Gérard; Hansen, Sven; Leterrier, Christine; Marchant-Forde, Jeremy; Marchant-Forde, Ruth; Minero, Michela; Mohr, Elmar; Prunier, Armelle; Valance, Dorothée; Veissier, Isabelle

    2007-10-22

    Measurement of heart rate variability (HRV) is a non-invasive technique that can be used to investigate the functioning of the autonomic nervous system, especially the balance between sympathetic and vagal activity. It has been proven to be very useful in humans for both research and clinical studies concerned with cardiovascular diseases, diabetic autonomic dysfunction, hypertension and psychiatric and psychological disorders. Over the past decade, HRV has been used increasingly in animal research to analyse changes in sympathovagal balance related to diseases, psychological and environmental stressors or individual characteristics such as temperament and coping strategies. This paper discusses current and past HRV research in farm animals. First, it describes how cardiac activity is regulated and the relationships between HRV, sympathovagal balance and stress and animal welfare. Then it proceeds to outline the types of equipment and methodological approaches that have been adapted and developed to measure inter-beats intervals (IBI) and estimate HRV in farm animals. Finally, it discusses experiments and conclusions derived from the measurement of HRV in pigs, cattle, horses, sheep, goats and poultry. Emphasis has been placed on deriving recommendations for future research investigating HRV, including approaches for measuring and analysing IBI data. Data from earlier research demonstrate that HRV is a promising approach for evaluating stress and emotional states in animals. It has the potential to contribute much to our understanding and assessment of the underlying neurophysiological processes of stress responses and different welfare states in farm animals. PMID:17320122

  9. Assessing the Relative Integrity of Formed Cardiac Linear Lesions by Recording Both Focal Monophasic Action Potentials and Contact Forces: A Technical Brief

    PubMed Central

    Benscoter, Mark A.

    2015-01-01

    The use of therapeutic ablation in patients with atrial fibrillation has become a mainstay in the treatment of this disease, yet often these individuals require multiple procedures. In other words, successful first time treatments are impacted by challenges, including the generation of linear lesions in certain anatomies like the mitral isthmus of the left atrium. Hence, there is a need to find ways to address the presence of unwanted conduction gaps at the time of lesion creation. In this paper, we describe a novel approach to examine conduction gaps, by using a proof of concept device to examine local electrical activation within the cardiac areas of an applied lesion, i.e., to locate gaps in the lesion set. To accomplish this, both epicardial and endocardial linear ablation lines composed of spot lesions with conduction gaps were created in a porcine model. The forces necessary to elicit monophasic action potentials (MAP) were collected from >200 measurements on the epicardium of the right ventricle. Ablations were then performed on the ventricular epicardium and left atrial mitral isthmus endocardially, while recording MAPs. We were able to successfully demonstrate the use of a proof of concept device to identify conduction gaps in linear lesion sets; furthermore, we were able to determine required contact forces to appropriately determine focal electrical changes of the underlying tissues. New catheter designs that incorporate capabilities to record focal MAPs could be employed clinically to better assess a given lesion quality and/or to determine the existence of an undesired conduction gap.

  10. Left atrial volume assessment in atrial fibrillation using multimodality imaging: a comparison of echocardiography, invasive three-dimensional CARTO and cardiac magnetic resonance imaging.

    PubMed

    Rabbat, Mark G; Wilber, David; Thomas, Kevin; Malick, Owais; Bashir, Atif; Agrawal, Anoop; Biswas, Santanu; Sanagala, Thriveni; Syed, Mushabbar A

    2015-06-01

    Left atrial size in atrial fibrillation is a strong predictor of successful ablation and cardiovascular events. Cardiac magnetic resonance multislice method (CMR-MSM) is the current gold standard for left atrial volume (LAV) assessment but is time consuming. We investigated whether LAV with more rapid area-length method by echocardiography (Echo-AL) or cardiac magnetic resonance (CMR-AL) and invasive measurement by 3D-CARTO mapping during ablation correlate with the CMR-MSM. We studied 250 consecutive patients prior to atrial fibrillation ablation. CMR images were acquired on 3T scanner to measure LAV by MSM and biplane area-length method. Standard echocardiography views were used to calculate LAV by biplane area-length method. LAV during ablation was measured by 3D-CARTO mapping. LAV was compared using intra-class correlation (ICC), Pearson's correlation and Bland-Altman plots. CMR-MSM was used as the reference standard. Mean LAV using CMR-MSM was 112.7 ± 36.7 ml. CMR-AL method overestimated LAV by 13.3 ± 21.8 ml (11.2%, p < 0.005) whereas 3D-CARTO and Echo-AL underestimated LAV by 8.3 ± 22.6 and 24.0 ± 27.6 ml respectively (8.7% and 20.0% respectively, p < 0.005). There was no significant difference between paroxysmal and persistent atrial fibrillation. CMR-AL and 3D-CARTO correlated and agreed well with CMR-MSM (r = 0.87 and 0.74, ICC = 0.80 and 0.77 respectively). However, Echo-AL had poor correlation and agreement with CMR-MSM (r = 0.66 and ICC = 0.48). Bland-Altman plots confirmed these findings. CMR-AL method may be used as an alternative to CMR-MSM, as it is non-invasive, rapid, and correlates well with CMR-MSM. LAV by different modalities should not be used interchangeably. PMID:25761533

  11. Assessment of dedicated low-dose cardiac micro-CT reconstruction algorithms using the left ventricular volume of small rodents as a performance measure

    SciTech Connect

    Maier, Joscha; Sawall, Stefan; Kachelrieß, Marc

    2014-05-15

    Purpose: Phase-correlated microcomputed tomography (micro-CT) imaging plays an important role in the assessment of mouse models of cardiovascular diseases and the determination of functional parameters as the left ventricular volume. As the current gold standard, the phase-correlated Feldkamp reconstruction (PCF), shows poor performance in case of low dose scans, more sophisticated reconstruction algorithms have been proposed to enable low-dose imaging. In this study, the authors focus on the McKinnon-Bates (MKB) algorithm, the low dose phase-correlated (LDPC) reconstruction, and the high-dimensional total variation minimization reconstruction (HDTV) and investigate their potential to accurately determine the left ventricular volume at different dose levels from 50 to 500 mGy. The results were verified in phantom studies of a five-dimensional (5D) mathematical mouse phantom. Methods: Micro-CT data of eight mice, each administered with an x-ray dose of 500 mGy, were acquired, retrospectively gated for cardiac and respiratory motion and reconstructed using PCF, MKB, LDPC, and HDTV. Dose levels down to 50 mGy were simulated by using only a fraction of the projections. Contrast-to-noise ratio (CNR) was evaluated as a measure of image quality. Left ventricular volume was determined using different segmentation algorithms (Otsu, level sets, region growing). Forward projections of the 5D mouse phantom were performed to simulate a micro-CT scan. The simulated data were processed the same way as the real mouse data sets. Results: Compared to the conventional PCF reconstruction, the MKB, LDPC, and HDTV algorithm yield images of increased quality in terms of CNR. While the MKB reconstruction only provides small improvements, a significant increase of the CNR is observed in LDPC and HDTV reconstructions. The phantom studies demonstrate that left ventricular volumes can be determined accurately at 500 mGy. For lower dose levels which were simulated for real mouse data sets, the HDTV algorithm shows the best performance. At 50 mGy, the deviation from the reference obtained at 500 mGy were less than 4%. Also the LDPC algorithm provides reasonable results with deviation less than 10% at 50 mGy while PCF and MKB reconstruction show larger deviations even at higher dose levels. Conclusions: LDPC and HDTV increase CNR and allow for quantitative evaluations even at dose levels as low as 50 mGy. The left ventricular volumes exemplarily illustrate that cardiac parameters can be accurately estimated at lowest dose levels if sophisticated algorithms are used. This allows to reduce dose by a factor of 10 compared to today's gold standard and opens new options for longitudinal studies of the heart.

  12. Random output and hospital performance.

    PubMed

    Barros, Pedro Pita

    2003-11-01

    Many countries are under pressure to reform health care financing and delivery. Hospital care is one part of the health system that is under scrutiny. Private management initiatives are a possible way to increase efficiency in health care delivery. This motivates the interest in developing methodologies to assess hospital performance, recognizing hospitals as a different sort of firm. We present a simple way to describe hospital production: hospital output as a change in the distribution of survival probabilities. This output definition allows us to separate hospital production from patients' characteristics. The notion of "better performance" has a precise meaning: (first-order) stochastic dominance of a distribution of survival probabilities over another distribution. As an illustration, we compare, for an important DRG, private and public management and find that private management performs better, mainly in the range of high-survival probabilities. The measured performance difference cannot be attributed to input prices or to economies of scale and/or scope. It reflects pure technological and organisational differences. PMID:14686628

  13. Comparison of the cardiac pumping capability and cardiac pumping reserve in double-muscled and conventional calves.

    PubMed

    Amory, H; McEntee, K; Linden, A S; Desmecht, D J; Beduin, J M; D'Orio, V; Lekeux, P M

    1993-12-01

    Hereditary muscular hypertrophy is a character that has been selected in several animal species for industrial meat production. The selection of this character in cattle produces animals of exceptional commercial value but ones with a lower aerobic capacity than that of conventional cattle. The purpose of this work was to study the role of cardiac function as a potential limiting factor of aerobic capacity in double-muscled calves. Two groups of healthy calves were studied, one consisting of nine calves of conventional conformation and the other of nine double-muscled calves. Pulmonary arterial and capillary wedge, central venous, and systemic arterial pressures were measured by fluid-filled catheters and recorded together with the electrocardiogram. Cardiac output was measured by the thermodilution technique. From these measurements, the heart rate, the cardiac and the stroke indices, the pulmonary and the systemic vascular resistances, and the cardiac power output were calculated. The parameters were recorded under basal resting conditions and during incremental dobutamine challenge, which allowed determination of the resting cardiac power output, the cardiac pumping capability, and the cardiac reserve. Dobutamine challenge induced a significant rise in cardiac and stroke indices, heart rate, and cardiac power output, a significant decrease in pulmonary and systemic vascular resistances, and no change in systemic and pulmonary arterial pressures. The cardiac reserve obtained in the present study was low in comparison with those previously reported in humans, dogs, and horses. This may be related to the poor running capability of bovine species relative to that of the former species.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8180890

  14. [Cardiac rehabilitation after myocardial infarction].

    PubMed

    Ghannem, M; Ghannem, L; Ghannem, L

    2015-12-01

    Although the proofs of the benefits of cardiac rehabilitation accumulate, many patients are not sent to rehabilitation units, especially younger and very elderly patients. As the length of stay in acute care units decreases, rehabilitation offers more time to fully assess the patients' conditions and needs. Meta-analyses of randomised trials suggest that mortality can be improved by as much as 20-30%. In addition, rehabilitation helps managing risk factors, including hyperlipidemia, diabetes, smoking and sedentary behaviours. Physical training also helps improving exercise capacity. Because of all of these effects, cardiac rehabilitation for post-myocardial infarction patients has been given a class IA recommendation in current guidelines. PMID:26548984

  15. Cardiac regeneration therapy: connections to cardiac physiology.

    PubMed

    Takehara, Naofumi; Matsubara, Hiroaki

    2011-12-01

    Without heart transplantation, a large number of patients with failing hearts worldwide face poor outcomes. By means of cardiomyocyte regeneration, cardiac regeneration therapy is emerging with great promise as a means for restoring loss of cardiac function. However, the limited success of clinical trials using bone marrow-derived cells and myoblasts with heterogeneous constituents, transplanted at a wide range of cell doses, has led to disagreement on the efficacy of cell therapy. It is therefore essential to reevaluate the evidence for the efficacy of cell-based cardiac regeneration therapy, focusing on targets, materials, and methodologies. Meanwhile, the revolutionary innovation of cardiac regeneration therapy is sorely needed to help the millions of people who suffer heart failure from acquired loss of cardiomyocytes. Cardiac regeneration has been used only in limited species or as a developing process in the rodent heart; now, the possibility of cardiomyocyte turnover in the human heart is being revisited. In the pursuit of this concept, the use of cardiac stem/progenitor stem cells in the cardiac niche must be focused to usher in a second era of cardiac regeneration therapy for the severely injured heart. In addition, tissue engineering and cellular reprogramming will advance the next era of treatment that will enable current cell-based therapy to progress to "real" cardiac regeneration therapy. Although many barriers remain, the prevention of refractory heart failure through cardiac regeneration is now becoming a realistic possibility. PMID:21963835

  16. A methodology for fast assessments to the electrical activity of barrel fields in vivo: from population inputs to single unit outputs

    PubMed Central

    Riera, Jorge J.; Goto, Takakuni; Kawashima, Ryuta

    2014-01-01

    Here we propose a methodology to analyze volumetric electrical activity of neuronal masses in the somatosensory barrel field of Wistar rats. The key elements of the proposed methodology are a three-dimensional microelectrode array, which was customized by our group to observe extracellular recordings from an extended area of the barrel field, and a novel method for the current source density analysis. By means of this methodology, we were able to localize single barrels from their event-related responses to single whisker deflection. It was also possible to assess the spatiotemporal dynamics of neuronal aggregates in several barrels at the same time with the resolution of single neurons. We used simulations to study the robustness of our methodology to unavoidable physiological noise and electrode configuration. We compared the accuracy to reconstruct neocortical current sources with that obtained with a previous method. This constitutes a type of electrophysiological microscopy with high spatial and temporal resolution, which could change the way we analyze the activity of cortical neurons in the future. PMID:24550785

  17. Assessment of radiochromic gel dosimeter based on Turnbull Blue dye for relative output factor measurements of the Leksell Gamma Knife® PerfexionTM

    NASA Astrophysics Data System (ADS)

    Kozubikova, P.; Solc, J.; Novotny, J., Jr.; Pilarova, K.; Pipek, J.; Koncekova, J.

    2015-01-01

    The aim of the study was to perform assessment of radiochromic gel dosimeter based on Turnbull blue dye formed by irradiation (TB gel dosimeter) for measurement of ROFs for 4 mm and 8 mm collimators for the Leksell Gamma Knife PerfexionTM. All measurements have been carried out using home-made spherical Perspex glass phantom of diameter 160 mm. TB gel dosimeters were scanned using homemade optical CT scanner. The results are compared with vendor recommended Monte Carlo calculated ROFs values of 0.814 and 0.900 for 4 mm and 8 mm collimators, respectively. The comparisons between the gel measurements and the treatment planning system (TPS) calculation are presented in the form of 2D isodoses for the central slices and 1D profile. Measured ROF 0.746 and 0.874 for 4 mm and 8 mm collimators respectively are in a reasonable agreement with vendor recommended values and measured relative dose distribution in a central slice and measured profiles of all shots show excellent correspondence with TPS.

  18. Quantitative Assessment of Cardiac Function in Fetuses of Women with Maternal Gestational Thyroid Dysfunction Using VVI Echocardiography

    PubMed Central

    Liu, Meixin; Yu, Jing; Fu, Xiuxiu; Wan, Wei

    2015-01-01

    Background The study aimed to investigate the clinical value of velocity vector imaging (VVI) in assessing heart function in fetuses of pregnant women with thyroid dysfunction. The inter-observer and intra-observer variability was assessed for all VVI parameters observed. Material/Methods The participants were enrolled from singleton pregnant women with gestational ages ranging 24+0 to 40+1 weeks who visited the Department of Obstetrics and Gynecology at the Affiliated Hospital of Qingdao University, China, for prenatal care from July 2011 to February 2014. Digital 2-dimensional (2D) dynamic 4-chamber images of the heart were collected. A total of qualified 226 images from 125 fetuses of pregnant women with normal thyroid (control group), 64 fetuses of pregnant women with hypothyroidism (hypothyroidism group), and 37 fetuses of pregnant women with hyperthyroidism (hyperthyroidism group) were interrogated offline using VVI software. The echocardiographic parameters including the myocardium peak systolic velocity (Vs), peak diastolic velocity (Vd), peak systolic strain (S), peak systolic strain rate (SRs), peak diastolic strain rate (SRd) of RV and LV, were obtained from the velocity curves of 2D myocardial motion. The heart rate was measured using a virtual M-mode algorithm built into the software. Results The study found that the longitudinal Vs and Vd of both ventricles in the control group gradually decreased from basal segments to apical segments and significantly increased over the gestation. S, SRs, and SRd of both ventricles remained stable after middle gestation. Compared with the control group, the hypothyroidism and hyperthyroidism groups exhibited significantly reduced S, SRs, and SRd, even for fetuses at 24-weeks gestation. There were no significant differences in global Vs and global Vd between the control group and the hyperthyroidism or hypothyroidism groups. Conclusions The thyroid dysfunction of pregnant women may damage fetal heart function, and VVI could be a sensitive technique to measure the variation of fetal heart function. PMID:26427319

  19. Cardiac output and cardiac contractility by impedance cardiography during exercise of runners

    NASA Technical Reports Server (NTRS)

    Kubicek, W. G.; Tracy, R. A.

    1994-01-01

    Most of the solid state electronic engineering of the system now generally known as the Minnesota Impedance Cardiograph was performed with the support of a five-year contract, NAS9-4500, with the NASA Lyndon B. Johnson Space Center, Houston, Texas. This contract ran from 1965 to 1970. In addition to the engineering design and development of the hardware, the contract called for testing on both animals and human subjects. This project also provided funds to construct twenty impedance cardiographs and place them in selected research and clinical facilities for further evaluation. This, then, led to the First Symposium on Impedance Cardiography, held at the NASA Lyndon B. Johnson Space Center, Houston, Texas, 2-4 June 1969. Twenty-four excellent papers were presented.

  20. Short-term cardiac adaptation to severe haemodilution: an echocardiographic study in normal and hypertensive subjects.

    PubMed

    Bombardini, T; Borghi, B; Zacà, F; Picano, E; Caroli, G C

    1994-05-01

    In order to avoid transfusion risks and optimize blood bank resources, in recent years many blood sparing techniques have been proposed, including severe haemodilution. The aim of this study is to assess the pattern of normal haemodynamic and cardiac adaptation to severe haemodilution in patients undergoing major orthopaedic surgery and refusing blood transfusions for religious reasons (the patients were Jehovah's Witnesses). Two-dimensionally guided M-mode echocardiograms were performed at baseline and 4 days after major orthopaedic surgery in 26 Jehovah's Witnesses (age 61 +/- 11 years), with normal regional and global baseline left ventricular function and no valvular disease. Left ventricular (LV) volumes were estimated by using the Teichholz formula. From the latter, we calculated ejection fraction and stroke volume, cardiac output (stroke volume x heart rate), and total peripheral resistance estimated as mean arterial pressure by cuff sphygmomanometer x 80/cardiac output. On the basis of LV mass (ASE-cube corrected by Devereux), two groups were identified: non-hypertrophic (LV mass index < 110 g.m-2 in women and < 130 g.m-2 in males) and hypertrophic. In the 19 patients without LV hypertrophy, haemoglobin decreased from 13.5 +/- 1.6 (mean +/- standard deviation) g.dl-1 (at baseline) to 8.7 +/- 1.3 post-operation (P < 0.01), and peripheral vascular resistances fell from 2131 +/- 450 to 1278 +/- 310 (dyne.s.cm-5) (P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8056003

  1. Cardiac AAV9 Gene Delivery Strategies in Adult Canines: Assessment by Long-term Serial SPECT Imaging of Sodium Iodide Symporter Expression.

    PubMed

    Moulay, Gilles; Ohtani, Tomohito; Ogut, Ozgur; Guenzel, Adam; Behfar, Atta; Zakeri, Rosita; Haines, Philip; Storlie, Jimmy; Bowen, Lorna; Pham, Linh; Kaye, David; Sandhu, Gurpreet; O'Connor, Michael; Russell, Stephen; Redfield, Margaret

    2015-07-01

    Heart failure is a leading cause of morbidity and mortality, and cardiac gene delivery has the potential to provide novel therapeutic approaches. Adeno-associated virus serotype 9 (AAV9) transduces the rodent heart efficiently, but cardiotropism, immune tolerance, and optimal delivery strategies in large animals are unclear. In this study, an AAV9 vector encoding canine sodium iodide symporter (NIS) was administered to adult immunocompetent dogs via epicardial injection, coronary infusion without and with cardiac recirculation, or endocardial injection via a novel catheter with curved needle and both end- and side-holes. As NIS mediates cellular uptake of clinical radioisotopes, expression was tracked by single-photon emission computerized tomography (SPECT) imaging in addition to Western blot and immunohistochemistry. Direct epicardial or endocardial injection resulted in strong cardiac expression, whereas expression after intracoronary infusion or cardiac recirculation was undetectable. A threshold myocardial injection dose that provides robust nonimmunogenic expression was identified. The extent of transmural myocardial expression was greater with the novel catheter versus straight end-hole needle delivery. Furthermore, the authors demonstrate that cardiac NIS reporter gene expression and duration can be quantified using serial noninvasive SPECT imaging up to 1 year after vector administration. These data are relevant to efforts to develop cardiac gene delivery as heart failure therapy. PMID:25915925

  2. Effects of lorazepam on cardiac vagal tone during rest and mental stress: assessment by means of spectral analysis.

    PubMed

    Tulen, J H; Mulder, G; Pepplinkhuizen, L; Man in 't Veld, A J; van Steenis, H G; Moleman, P

    1994-02-01

    Dose-dependent effects of intravenously administered lorazepam on haemodynamic fluctuations were studied by means of spectral analysis, in order to elucidate sympathetic and parasympathetic components in cardiovascular control during situations of rest and mental stress after benzodiazepine administration. In a double-blind randomized cross-over study, nine male volunteers participated in two sessions: a placebo and lorazepam session. During these sessions, the subjects repeatedly performed a 10-min version of the Stroop Color Word Test (CWT), with 10 min of rest between the CWTs. Lorazepam was administered before each rest period in increasing doses of 0.0, 0.06, 0.13, 0.25 and 0.5 mg (total cumulative dose: 0.94 mg). During the placebo session the subjects received five placebo injections. For five of the nine subjects the lorazepam session was their first session. Heat rate (HR), blood pressure (BP) and respiration were recorded continuously. Power spectra were calculated per 2.5-min periods for HR, systolic (SBP) and diastolic BP (DBP). Spectral density was assessed for three frequency bands: low (LFB: 0.02-0.06 Hz), mid (MFB: 0.07-0.14 Hz) and high (HFB: 0.15-0.40 Hz). During the consecutive periods of rest, lorazepam induced a dose-dependent decrease in HR, and a dose-dependent increase in LFB, MFB and HFB power of HR, but lorazepam had no effect on BP. The effects were significant after 0.44 mg lorazepam for HR and HFB power, and after 0.94 mg lorazepam for the HR fluctuations in the LFB and MFB. Lorazepam did not influence the cardiovascular responses to the CWT.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7846210

  3. Taurine depresses cardiac contractility and enhances systemic heart glucose utilization in the cuttlefish, Sepia officinalis.

    PubMed

    MacCormack, Tyson J; Callaghan, N I; Sykes, A V; Driedzic, W R

    2016-02-01

    Taurine is the most abundant amino acid in the blood of the cuttlefish, Sepia officinalis, where levels can exceed 200 mmol L(-1). In mammals, intracellular taurine modulates cardiac Ca(2+) handling and carbohydrate metabolism at much lower concentrations but it is not clear if it exerts similar actions in cephalopods. Blood Ca(2+) levels are high in cephalopods and we hypothesized that taurine would depress cardiac Ca(2+) flux and modulate contractility in systemic and branchial hearts of cuttlefish. Heart performance was assessed with an in situ perfused systemic heart preparation and contractility was evaluated using isometrically contracting systemic and branchial heart muscle rings. Stroke volume, cardiac output, and Ca(2+) sensitivity were significantly lower in systemic hearts perfused with supplemental taurine (100 mmol L(-1)) than in controls. In muscle ring preparations, taurine impaired relaxation at high contraction frequencies, an effect abolished by supra-physiological Ca(2+) levels. Taurine did not affect oxygen consumption in non-contracting systemic heart muscle, but extracellular glucose utilization was twice that of control preparations. Collectively, our results suggest that extracellular taurine depresses cardiac Ca(2+) flux and potentiates glucose utilization in cuttlefish. Variations in taurine levels may represent an important mechanism for regulating cardiovascular function and metabolism in cephalopods. PMID:26644087

  4. Diabetes and cardiac autonomic neuropathy: Clinical manifestations, cardiovascular consequences, diagnosis and treatment

    PubMed Central

    Balcıoğlu, Akif Serhat; Müderrisoğlu, Haldun

    2015-01-01

    Cardiac autonomic neuropathy (CAN) is a frequent chronic complication of diabetes mellitus with potentially life-threatening outcomes. CAN is caused by the impairment of the autonomic nerve fibers regulating heart rate, cardiac output, myocardial contractility, cardiac electrophysiology and blood vessel constriction and dilatation. It causes a wide range of cardiac disorders, including resting tachycardia, arrhythmias, intraoperative cardiovascular instability, asymptomatic myocardial ischemia and infarction and increased rate of mortality after myocardial infarction. Etiological factors associated with autonomic neuropathy include insufficient glycemic control, a longer period since the onset of diabetes, increased age, female sex and greater body mass index. The most commonly used methods for the diagnosis of CAN are based upon the assessment of heart rate variability (the physiological variation in the time interval between heartbeats), as it is one of the first findings in both clinically asymptomatic and symptomatic patients. Clinical symptoms associated with CAN generally occur late in the disease process and include early fatigue and exhaustion during exercise, orthostatic hypotension, dizziness, presyncope and syncope. Treatment is based on early diagnosis, life style changes, optimization of glycemic control and management of cardiovascular risk factors. Medical therapies, including aldose reductase inhibitors, angiotensin-converting enzyme inhibitors, prostoglandin analogs and alpha-lipoic acid, have been found to be effective in randomized controlled trials. The following article includes the epidemiology, clinical findings and cardiovascular consequences, diagnosis, and approaches to prevention and treatment of CAN. PMID:25685280

  5. Protocol for the China PEACE (Patient-centered Evaluative Assessment of Cardiac Events) retrospective study of coronary catheterisation and percutaneous coronary intervention

    PubMed Central

    Li, Jing; Dharmarajan, Kumar; Li, Xi; Lin, Zhenqiu; Normand, Sharon-Lise T; Krumholz, Harlan M; Jiang, Lixin

    2014-01-01

    Introduction During the past decade, the volume of percutaneous coronary intervention (PCI) in China has risen by more than 20-fold. Yet little is known about patterns of care and outcomes across hospitals, regions and time during this period of rising cardiovascular disease and dynamic change in the Chinese healthcare system. Methods and analysis Using the China PEACE (Patient-centered Evaluative Assessment of Cardiac Events) research network, the Retrospective Study of Coronary Catheterisation and Percutaneous Coronary Intervention (China PEACE-Retrospective CathPCI Study) will examine a nationally representative sample of 11 900 patients who underwent coronary catheterisation or PCI at 55 Chinese hospitals during 2001, 2006 and 2011. We selected patients and study sites using a two-stage cluster sampling design with simple random sampling stratified within economical-geographical strata. A central coordinating centre will monitor data quality at the stages of case ascertainment, medical record abstraction and data management. We will examine patient characteristics, diagnostic testing patterns, procedural treatments and in-hospital outcomes, including death, complications of treatment and costs of hospitalisation. We will additionally characterise variation in treatments and outcomes by patient characteristics, hospital, region and study year. Ethics and dissemination The China PEACE collaboration is designed to translate research into improved care for patients. The study protocol was approved by the central ethics committee at the China National Center for Cardiovascular Diseases (NCCD) and collaborating hospitals. Findings will be shared with participating hospitals, policymakers and the academic community to promote quality monitoring, quality improvement and the efficient allocation and use of coronary catheterisation and PCI in China. Registration details http://www.clinicaltrials.gov (NCT01624896). PMID:24607563

  6. Assessment of the cardiac safety of prucalopride in healthy volunteers: a randomized, double-blind, placebo- and positive-controlled thorough QT study

    PubMed Central

    Mendzelevski, Boaz; Ausma, Jannie; Chanter, Dennis O; Robinson, Patricia; Kerstens, Rene; Vandeplassche, Lieve; Camm, John

    2012-01-01

    AIMS To assess steady-state effects of therapeutic and supra-therapeutic doses of prucalopride on the QT interval using a novel design involving a parallel placebo group with nested crossover for positive control. METHODS A double-blind, double-dummy, placebo- and active-controlled study was conducted in 120 healthy male and female volunteers (NCT00903747). Volunteers were randomized to receive prucalopride 2–10 mg once daily (therapeutic and supratherapeutic doses, respectively) (group 1), placebo with 400 mg moxifloxacin on day 1 (group 2a), or placebo with moxifloxacin on day 15 (group 2b). Twelve-lead 24 h Holter ECGs recorded at various time-points were evaluated blind and centrally. RESULTS Estimated mean difference in study specific corrected QT interval (QTcSS) time-matched change from baseline between prucalopride (2 and 10 mg) and placebo was <5 ms at all time points (maximum mean difference: 3.83 ms at 3.5 h post dose on day 5 with 2 mg [90% Cl −0.33, 6.38 ms]). Upper limits of the two-sided 90% CI for QTcSS were all <10 ms. There were no outlying QTcSS values >450 ms and no subjects had an increase >60 ms following prucalopride. Moxifloxacin produced the expected significant changes in QTcSS (>5 ms, maximum of +12.7 ms at 5 h post dose) at all time-points except 1 h post dose. Prucalopride resulted in small increases in heart rate (maximum of 5.8 beats min–1), which were similar for 2 and 10 mg. Prucalopride was well tolerated after first day of treatment. CONCLUSION Prucalopride at both therapeutic and supra therapeutic doses has no clinically significant effects on cardiac repolarisation in healthy volunteers. PMID:21848574

  7. Cerebral Oximetry as a Real-Time Monitoring Tool to Assess Quality of In-Hospital Cardiopulmonary Resuscitation and Post Cardiac Arrest Care

    PubMed Central

    Ibrahim, Akram W; Trammell, Antoine R; Austin, Harland; Barbour, Kenya; Onuorah, Emeka; House, Dorothy; Miller, Heather L; Tutt, Chandila; Combs, Deborah; Phillips, Roger; Dickert, Neal W; Zafari, A Maziar

    2015-01-01

    Background Regional cerebral oxygen saturation (rSO2) as assessed by near infrared frontal cerebral spectroscopy decreases in circulatory arrest and increases with high-quality cardiopulmonary resuscitation. We hypothesized that higher rSO2 during cardiopulmonary resuscitation and after return of spontaneous circulation (ROSC) would predict survival to discharge and neurological recovery. Methods and Results This prospective case series included patients experiencing in-hospital cardiac arrest. Cerebral oximetry was recorded continuously from initiation of resuscitation until ROSC and up to 48 hours post-arrest. Relationships between oximetry data during these time periods and outcomes of resuscitation survival and survival to discharge were analyzed. The cohort included 27 patients. Nineteen (70.3%) achieved ROSC, and 8 (29.6%) survived to discharge. Median arrest duration was 20.8 minutes (range =8 to 74). There was a significant difference in rSO2 between resuscitation survivors and resuscitation nonsurvivors at initiation of the resuscitative efforts (35% versus 17.5%, P =0.03) and during resuscitation (36% versus 15%, P =0.0008). No significant association was observed between rSO2 at ROSC or during the post-arrest period and survival to discharge. Among patients who survived to discharge, there was no association between cerebral performance category and rSO2 at ROSC, during resuscitation, or post-arrest. Conclusions Higher rSO2 levels at initiation of resuscitation and during resuscitation are associated with resuscitation survival and may reflect high-quality cardiopulmonary resuscitation. However, in this small series, rSO2 was not predictive of good neurological outcome. Larger studies are needed to determine whether this monitoring modality can be used to improve clinical outcomes. PMID:26307569

  8. Cardiac overexpression of human VEGF165 by recombinant Semliki Forest virus leads to adverse effects in pressure-induced heart failure

    PubMed Central

    Loot, A.E.; Roks, A.J.M.; Westermann, D.; Orzechowski, H-D.; Tschpe, C.; Wilschut, J.C.; Tio, R.A.; van Gilst, W.H.; Henning, R.H.

    2007-01-01

    Semliki Forest virus (SFV) is an efficient vector for cardiac gene delivery. The relatively short transgene expression induced by SFV seems appropriate for angiogenic gene therapy. We tested the effects of SFV expressing vascular endothelial growth factor (VEGF) on cardiac angiogenesis and heart failure in the mRen2 transgenic rat. Six-week-old mRen2 rats received SFV-VEGF or control virus (n=7 each) administered intracoronarily. Twelve days after transfection, cardiac capillary density and function were assessed. Capillary density in cardiac regions where SFV expression was highest had decreased by 20% in the SFV-VEGF-treated group. The decrease in capillary density was accompanied by impaired systolic function as illustrated by increased endsystolic volumes and a 34% decrease in cardiac output. We conclude that the time frame of SFV expression is sufficient to induce structural alterations, but that VEGF in mRen2 transgenic rats did not elicit the expected angiogenic effect. Rather, capillary density was decreased and subsequently cardiac function was impaired. This paradoxical finding is possibly related to the pathophysiology associated with this model and warrants caution if one is to pursue VEGF-mediated, angiogenic therapy before proceeding to a clinical setting. (Neth Heart J 2007;15:335-41.18167566) PMID:18167566

  9. Cardiac overexpression of human VEGF(165) by recombinant Semliki Forest virus leads to adverse effects in pressure-induced heart failure.

    PubMed

    Loot, A E; Roks, A J M; Westermann, D; Orzechowski, H-D; Tschpe, C; Wilschut, J C; Tio, R A; van Gilst, W H; Henning, R H

    2007-01-01

    Semliki Forest virus (SFV) is an efficient vector for cardiac gene delivery. The relatively short transgene expression induced by SFV seems appropriate for angiogenic gene therapy. We tested the effects of SFV expressing vascular endothelial growth factor (VEGF) on cardiac angiogenesis and heart failure in the mRen2 transgenic rat.Six-week-old mRen2 rats received SFV-VEGF or control virus (n=7 each) administered intracoronarily. Twelve days after transfection, cardiac capillary density and function were assessed. Capillary density in cardiac regions where SFV expression was highest had decreased by 20% in the SFV-VEGF-treated group. The decrease in capillary density was accompanied by impaired systolic function as illustrated by increased endsystolic volumes and a 34% decrease in cardiac output.We conclude that the time frame of SFV expression is sufficient to induce structural alterations, but that VEGF in mRen2 transgenic rats did not elicit the expected angiogenic effect. Rather, capillary density was decreased and subsequently cardiac function was impaired. This paradoxical finding is possibly related to the pathophysiology associated with this model and warrants caution if one is to pursue VEGF-mediated, angiogenic therapy before proceeding to a clinical setting. (Neth Heart J 2007;15:335-41.). PMID:18167566

  10. What Is Cardiac Rehabilitation?

    MedlinePlus

    ANSWERS by heart Treatments + Tests What Is Cardiac Rehabilitation? A cardiac rehabilitation (rehab) program takes place in a hospital or ... special help in making lifestyle changes. During your rehabilitation program you’ll… • Have a medical evaluation to ...

  11. Influence of cirrhosis in cardiac surgery outcomes

    PubMed Central

    Lopez-Delgado, Juan C; Esteve, Francisco; Javierre, Casimiro; Ventura, Josep L; Mañez, Rafael; Farrero, Elisabet; Torrado, Herminia; Rodríguez-Castro, David; Carrio, Maria L

    2015-01-01

    Liver cirrhosis has evolved an important risk factor for cardiac surgery due to the higher morbidity and mortality that these patients may suffer compared with general cardiac surgery population. The presence of contributing factors for a poor outcome, such as coagulopathy, a poor nutritional status, an adaptive immune dysfunction, a degree of cirrhotic cardiomyopathy, and a degree of renal and pulmonary dysfunction, have to be taken into account for surgical evaluation when cardiac surgery is needed, together with the degree of liver disease and its primary complications. The associated pathophysiological characteristics that liver cirrhosis represents have a great influence in the development of complications during cardiac surgery and the postoperative course. Despite the population of cirrhotic patients who are referred for cardiac surgery is small and recommendations come from small series, since liver cirrhotic patients have increased their chance of survival in the last 20 years due to the advances in their medical care, which includes liver transplantation, they have been increasingly considered for cardiac surgery. Indeed, there is an expected rise of cirrhotic patients within the cardiac surgical population due to the increasing rates of non-alcoholic fatty liver disease and non-alcoholic steatohepatitis, especially in western countries. In consequence, a more specific approach is needed in the assessment of care of these patients if we want to improve their management. In this article, we review the pathophysiology and outcome prediction of cirrhotic patients who underwent cardiac surgery. PMID:25914775

  12. Can Exercise Capacity Assessed by the 6 Minute Walk Test Predict the Development of Major Adverse Cardiac Events in Patients with STEMI after Fibrinolysis?

    PubMed Central

    Hassan, Ayman K. M.; Dimitry, Salwa R.; Agban, George W.

    2014-01-01

    Background To assess the added value of the 6 minute walk test distance (6MWTD) in the risk-stratification methods for patients with ST -segment elevation myocardial infarction (STEMI) treated with fibrinolysis. Methodology/Principal Findings This is a prospective cohort study of one hundred consecutive patients with STEMI, who had received fibrinolysis, at Assuit University Hospital. All patients underwent 6MWT pre- discharge and were followed up for 3 months to monitor the incidence of major adverse cardiac events (MACE). Patients were divided into 3 groups according to the level of 6MWTD (level I>450 m, level II = 300–450 m and level III<300 m). Among the study population, the median 6MWT distance was 370 meters (interquartile range 162–462). The mean age was 60.9±10.7 years, 71.9% of them were males, 2/3 had anterior MI. only 10.5% had successful thrombolysis. Compared to patients in level I (>450 m), patients in level III (<300 m) were more likely to have clinical risk factors as hypertension, diabetes and impaired renal function. The patient's mean TIMI score was 3.4±2.2, the mean GRACE score was 150.5±27.7. There was a significant negative correlation between the 6 MWTD and GRACE risk score (r = −0.80, p<0.001). At 3 months of follow-up, 51% had MACE including 16% were dead. Multivariate logistic regression analysis identified that the GRACE risk score and 6MWT distance levels were the best predictors of the MACE at 3 month of follow up. The incidence of MACE was 4 times higher in patients with high GRACE risk score who couldn't walk more than 300 meters (OR = 4.66, 95% CI = 1.1–14.5, p = 0.006). Conclusions/Significance In patients with STEMI treated with fibrinolysis, the addition of 6MWTD assessment pre-discharge to the traditional GRACE risk score improved the risk prediction of cardiovascular events at 3 month follow up. PMID:24905094

  13. Haemodynamic goal-directed therapy in cardiac and vascular surgery. A systematic review and meta-analysis.

    PubMed

    Giglio, Mariateresa; Dalfino, Lidia; Puntillo, Filomena; Rubino, Giovanni; Marucci, Massimo; Brienza, Nicola

    2012-11-01

    In cardiovascular surgery, reduced organ perfusion and oxygen delivery contribute to increased postoperative morbidity and prolonged intensive care unit stay. Goal-directed therapy (GDT), a perioperative haemodynamic strategy aiming to increase cardiac output, is helpful in preventing postoperative complications, but studies in the context of cardiovascular surgery have produced conflicting results. The purpose of the present meta-analysis is to determine the effects of perioperative haemodynamic goal-directed therapy on mortality and morbidity in cardiac and vascular surgery. MEDLINE, EMBASE, The Cochrane Library and the DARE databases were searched until July 2011. Randomized controlled trials reporting on adult cardiac or vascular surgical patients managed with perioperative GDT or according to routine haemodynamic practice were included. Primary outcome measures were mortality and morbidity. Data synthesis was obtained by using odds ratio (OR) with 95% confidence interval (CI) by a random effects model. An OR <1 favoured GDT. Statistical heterogeneity was assessed by Q and I(2) statistics. Eleven articles (five cardiac surgery and six vascular procedures), enrolling a total sample of 1179 patients, were included in the analysis. As compared with routine haemodynamic practice, perioperative GDT did not reduce mortality in either cardiac or vascular surgery (pooled OR 0.87; 95% CI 0.37-2.02; statistical power 64%). GDT significantly reduced the number of cardiac patients with complications (OR 0.34; 95% CI 0.18-0.63; P = 0.0006), but no effect was observed in vascular patients (OR, 0.84; 95% CI 0.45-1.56; P = 0.58). Perioperative GDT prevents postoperative complications in cardiac surgery patients, while it has no effect in vascular surgery. The different characteristics and comorbidities of the population enrolled could explain these conflicting results. More trials conforming to the characteristics of low-risk-of-bias studies and enrolling a larger and well-defined population of patients are needed to better clarify the effect of GDT in the specific setting of cardiovascular surgery. PMID:22833509

  14. Serial Input Output

    SciTech Connect

    Waite, Anthony; /SLAC

    2011-09-07

    Serial Input/Output (SIO) is designed to be a long term storage format of a sophistication somewhere between simple ASCII files and the techniques provided by inter alia Objectivity and Root. The former tend to be low density, information lossy (floating point numbers lose precision) and inflexible. The latter require abstract descriptions of the data with all that that implies in terms of extra complexity. The basic building blocks of SIO are streams, records and blocks. Streams provide the connections between the program and files. The user can define an arbitrary list of streams as required. A given stream must be opened for either reading or writing. SIO does not support read/write streams. If a stream is closed during the execution of a program, it can be reopened in either read or write mode to the same or a different file. Records represent a coherent grouping of data. Records consist of a collection of blocks (see next paragraph). The user can define a variety of records (headers, events, error logs, etc.) and request that any of them be written to any stream. When SIO reads a file, it first decodes the record name and if that record has been defined and unpacking has been requested for it, SIO proceeds to unpack the blocks. Blocks are user provided objects which do the real work of reading/writing the data. The user is responsible for writing the code for these blocks and for identifying these blocks to SIO at run time. To write a collection of blocks, the user must first connect them to a record. The record can then be written to a stream as described above. Note that the same block can be connected to many different records. When SIO reads a record, it scans through the blocks written and calls the corresponding block object (if it has been defined) to decode it. Undefined blocks are skipped. Each of these categories (streams, records and blocks) have some characteristics in common. Every stream, record and block has a name with the condition that each stream, record or block name must be unique in its category (i.e. all streams must have different names, but a stream can have the same name as a record). Each category is an arbitrary length list which is handled by a 'manager' and there is one manager for each category.

  15. Validation of On-Orbit Methodology for the Assessment of Cardiac Function and Changes in the Circulating Volume Using "Braslet-M" Occlusion Cuffs

    NASA Technical Reports Server (NTRS)

    Hamilton, D. R.; Sargsyan, A. E.; Garcia, K. M.; Ebert, D.; Feiveson, A. H.; Alferova, I. V.; Dulchavsky, S. A.; Matveev, V. P.; Bogomolov, V. V.; Duncan, J. M.

    2011-01-01

    BACKGROUND: The transition to microgravity eliminates the hydrostatic gradients in the vascular system. The resulting fluid redistribution commonly manifests as facial edema, engorgement of the external neck veins, nasal congestion, and headache. This experiment examined the responses to modified Valsalva and Mueller maneuvers as measured by cardiac and vascular ultrasound in a baseline microgravity steady state, and under the influence of thigh occlusion cuffs (Braslet cuffs). METHODS: Nine International Space Station crewmember subjects (Expeditions 16 - 20) were examined in 15 experiment sessions 101 46 days after launch (mean SD; 33 - 185). 27 cardiac and vascular parameters were obtained under three respiratory conditions (baseline, Valsalva, and Mueller) before and after tightening of the Braslet cuffs for a total of 162 data points per session. The quality of cardiac and vascular ultrasound examinations was assured through remote monitoring and guidance by Investigators from the NASA Telescience Center in Houston, TX, USA. RESULTS: Fourteen of the 81 measured conditions were significantly different with Braslet application and were apparently related to cardiac preload reduction or increase in the venous volume sequestered in the lower extremity. These changes represented 10 of the 27 parameters measured. In secondary analysis, 7 of the 27 parameters were found to respond differently to respiratory maneuvers depending on the presence or absence of thigh compression, with a total of 11 differences. CONCLUSIONS: Acute application of Braslet occlusion cuffs causes lower extremity fluid sequestration and exerts proportionate measurable effects on cardiac performance in microgravity. Ultrasound techniques measuring the hemodynamic effects of thigh cuffs in combination with respiratory maneuvers may serve as an effective tool in determining the volume status of a cardiac or hemodynamically compromised patient in microgravity.

  16. A rare case of primary cardiac lymphoma.

    PubMed

    Khan-Kheil, Ayisha Mehtab; Mustafa, Hanif Muhammad; Anand, Dhakshinamurthy Vijay; Banerjee, Prithwish

    2015-01-01

    A 71-year-old man presented with shortness of breath and tachycardia along with systemic symptoms of weight loss and lethargy. A pulmonary embolus was the initial suspected diagnosis but through extensive investigations a rarer cause of his symptoms was identified. This case demonstrates the importance of cardiac imaging in the assessment and non-invasive tissue characterisation of a suspected cardiac tumour; in our case, this was subsequently confirmed by careful histological/immunocytochemical evaluation of the pericardial effusion as a primary cardiac B-cell non-Hodgkin's lymphoma, thus enabling appropriate management leading to an excellent clinical outcome. PMID:26538249

  17. Delivering expert cardiac support in the community.

    PubMed

    Paynter, Mike

    2007-10-01

    This article outlines how cardiac problems can be assessed in the primary care environment, improving patient care and helping alleviate some of the operational and financial burdens on secondary and emergency care providers. It examines the approach that Bridgwater Community Hospital took in monitoring and managing cardiac conditions within primary care. By opting for a cardiac telemedicine service, clinicians get fast, expert interpretation of ECG results, enabling them to deliver timely and more effective, preventative care, as well as delivering clear cost benefits across the trust, and ensuring healthcare resources are optimized. PMID:18073646

  18. Lightweight multiple output converter development

    NASA Technical Reports Server (NTRS)

    Kisch, J. J.; Martinelli, R. M.

    1978-01-01

    A high frequency, multiple output power conditioner was developed and breadboarded using an eight-stage capacitor diode voltage multiplier to provide +1200 Vdc, and a three-stage for -350 Vdc. In addition, two rectifier bridges were capacitively coupled to the eight-stage multiplier to obtain 0.5 and 0.65 a dc constant current outputs referenced to +1200 Vdc. Total power was 120 watts, with an overall efficiency of 85 percent at the 80 kHz operating frequency. All outputs were regulated to three percent or better, with complete short circuit protection. The power conditioner component weight and efficiency were compared to the equivalent four outputs of the 10 kHz conditioner for the 8 cm ion engine. Weight reduct