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Sample records for cardiac flow assessment

  1. Cardiac tumors: echo assessment.

    Science.gov (United States)

    Mankad, Rekha; Herrmann, Joerg

    2016-12-01

    Cardiac tumors are exceedingly rare (0.001-0.03% in most autopsy series). They can be present anywhere within the heart and can be attached to any surface or be embedded in the myocardium or pericardial space. Signs and symptoms are nonspecific and highly variable related to the localization, size and composition of the cardiac mass. Echocardiography, typically performed for another indication, may be the first imaging modality alerting the clinician to the presence of a cardiac mass. Although echocardiography cannot give the histopathology, certain imaging features and adjunctive tools such as contrast imaging may aid in the differential diagnosis as do the adjunctive clinical data and the following principles: (1) thrombus or vegetations are the most likely etiology, (2) cardiac tumors are mostly secondary and (3) primary cardiac tumors are mostly benign. Although the finding of a cardiac mass on echocardiography may generate confusion, a stepwise approach may serve well practically. Herein, we will review such an approach and the role of echocardiography in the assessment of cardiac masses.

  2. Cardiac Risk Assessment

    Science.gov (United States)

    ... Risk Assessment Related tests: Lipid Profile , VLDL Cholesterol , hs-CRP , Lp(a) Overview | Common Questions | Related Pages What ... cardiac risk include: High-sensitivity C-reactive protein (hs-CRP) : Studies have shown that measuring CRP with a ...

  3. Relationship between cardiac function and resting cerebral blood flow

    DEFF Research Database (Denmark)

    Henriksen, Otto M; Jensen, Lars T; Krabbe, Katja;

    2014-01-01

    Although both impaired cardiac function and reduced cerebral blood flow are associated with ageing, current knowledge of the influence of cardiac function on resting cerebral blood flow (CBF) is limited. The aim of this study was to investigate the potential effects of cardiac function on CBF. CBF...... and cardiac output were measured in 31 healthy subjects 50-75 years old using magnetic resonance imaging techniques. Mean values of CBF, cardiac output and cardiac index were 43.6 ml per 100 g min(-1), 5.5 l min(-1) and 2.7 l min(-1) m(-2), respectively, in males, and 53.4 ml per 100 g min(-1), 4.3 l min(-1......) and 2.4 l min(-1) m(-2), respectively, in females. No effects of cardiac output or cardiac index on CBF or structural signs of brain ageing were observed. However, fractional brain flow defined as the ratio of total brain flow to cardiac output was inversely correlated with cardiac index (r(2) = 0.22, P...

  4. Ultrasound assessment of fetal cardiac function

    Science.gov (United States)

    Crispi, Fàtima; Valenzuela‐Alcaraz, Brenda; Cruz‐Lemini, Monica

    2015-01-01

    Abstract Introduction: Fetal heart evaluation with US is feasible and reproducible, although challenging due to the smallness of the heart, the high heart rate and limited access to the fetus. However, some cardiac parameters have already shown a strong correlation with outcomes and may soon be incorporated into clinical practice. Materials and Methods: Cardiac function assessment has proven utility in the differential diagnosis of cardiomyopathies or prediction of perinatal mortality in congenital heart disease. In addition, some cardiac parameters with high sensitivity such as MPI or annular peak velocities have shown promising results in monitoring and predicting outcome in intrauterine growth restriction or congenital diaphragmatic hernia. Conclusion: Cardiac function can be adequately evaluated in most fetuses when appropriate expertise, equipment and time are available. Fetal cardiac function assessment is a promising tool that may soon be incorporated into clinical practice to diagnose, monitor or predict outcome in some fetal conditions. Thus, more research is warranted to further define specific protocols for each fetal condition that may affect cardiac function. PMID:28191192

  5. Assessment of cardiac sympathetic nerve integrity with positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Raffel, David M. E-mail: raffel@umich.edu; Wieland, Donald M

    2001-07-01

    The autonomic nervous system plays a critical role in the regulation of cardiac function. Abnormalities of cardiac innervation have been implicated in the pathophysiology of many heart diseases, including sudden cardiac death and congestive heart failure. In an effort to provide clinicians with the ability to regionally map cardiac innervation, several radiotracers for imaging cardiac sympathetic neurons have been developed. This paper reviews the development of neuronal imaging agents and discusses their emerging role in the noninvasive assessment of cardiac sympathetic innervation.

  6. Simulation evaluation of quantitative myocardial perfusion assessment from cardiac CT

    Science.gov (United States)

    Bindschadler, Michael; Modgil, Dimple; Branch, Kelley R.; La Riviere, Patrick J.; Alessio, Adam M.

    2014-03-01

    Contrast enhancement on cardiac CT provides valuable information about myocardial perfusion and methods have been proposed to assess perfusion with static and dynamic acquisitions. There is a lack of knowledge and consensus on the appropriate approach to ensure 1) sufficient diagnostic accuracy for clinical decisions and 2) low radiation doses for patient safety. This work developed a thorough dynamic CT simulation and several accepted blood flow estimation techniques to evaluate the performance of perfusion assessment across a range of acquisition and estimation scenarios. Cardiac CT acquisitions were simulated for a range of flow states (Flow = 0.5, 1, 2, 3 ml/g/min, cardiac output = 3,5,8 L/min). CT acquisitions were simulated with a validated CT simulator incorporating polyenergetic data acquisition and realistic x-ray flux levels for dynamic acquisitions with a range of scenarios including 1, 2, 3 sec sampling for 30 sec with 25, 70, 140 mAs. Images were generated using conventional image reconstruction with additional image-based beam hardening correction to account for iodine content. Time attenuation curves were extracted for multiple regions around the myocardium and used to estimate flow. In total, 2,700 independent realizations of dynamic sequences were generated and multiple MBF estimation methods were applied to each of these. Evaluation of quantitative kinetic modeling yielded blood flow estimates with an root mean square error (RMSE) of ~0.6 ml/g/min averaged across multiple scenarios. Semi-quantitative modeling and qualitative static imaging resulted in significantly more error (RMSE = ~1.2 and ~1.2 ml/min/g respectively). For quantitative methods, dose reduction through reduced temporal sampling or reduced tube current had comparable impact on the MBF estimate fidelity. On average, half dose acquisitions increased the RMSE of estimates by only 18% suggesting that substantial dose reductions can be employed in the context of quantitative myocardial

  7. Intraoperative Cardiac Ultrasound Examination Using Vector Flow Imaging

    DEFF Research Database (Denmark)

    Hansen, Kristoffer Lindskov; Pedersen, Mads Møller; Møller-Sørensen, Hasse

    2013-01-01

    Conventional ultrasound (US) methods for blood velocity estimation only provide onedimensional and angle-dependent velocity estimates; thus, the complexity of cardiac flow has been difficult to measure. To circumvent these limitations, the Transverse Oscillation (TO) vector flow method has been...

  8. Cardiac cell proliferation assessed by EdU, a novel analysis of cardiac regeneration.

    Science.gov (United States)

    Zeng, Bin; Tong, Suiyang; Ren, Xiaofeng; Xia, Hao

    2016-08-01

    Emerging evidence suggests that mammalian hearts maintain the capacity for cardiac regeneration. Rapid and sensitive identification of cardiac cellular proliferation is prerequisite for understanding the underlying mechanisms and strategies of cardiac regeneration. The following immunologically related markers of cardiac cells were analyzed: cardiac transcription factors Nkx2.5 and Gata 4; specific marker of cardiomyocytes TnT; endothelial cell marker CD31; vascular smooth muscle marker smooth muscle myosin IgG; cardiac resident stem cells markers IsL1, Tbx18, and Wt1. Markers were co-localized in cardiac tissues of embryonic, neonatal, adult, and pathological samples by 5-ethynyl-2'-deoxyuridine (EdU) staining. EdU was also used to label isolated neonatal cardiomyocytes in vitro. EdU robustly labeled proliferating cells in vitro and in vivo, co-immunostaining with different cardiac cells markers. EdU can rapidly and sensitively label proliferating cardiac cells in developmental and pathological states. Cardiac cell proliferation assessed by EdU is a novel analytical tool for investigating the mechanism and strategies of cardiac regeneration in response to injury.

  9. Temporal changes in cardiac function and cerebral blood flow during sequential postmenopausal hormone replacement

    DEFF Research Database (Denmark)

    Sørensen, M B; Fritz-Hansen, T; Jensen, H H;

    2001-01-01

    OBJECTIVE: The purpose was to assess the temporal changes in cardiac function and cerebral blood flow during postmenopausal administration of estrogen with and without progestogen. STUDY DESIGN: Sixteen postmenopausal volunteers were assessed during estradiol plus sequential norethindrone acetate...... and placebo in two 12-week periods. Temporal changes were measured by magnetic resonance flow mapping 8 times. RESULTS: Systemic vascular resistance was reduced during estradiol (-6.9%; P ... (maximum increase, 5.2%; P Cerebral blood flow was reduced after 9 weeks of hormone replacement therapy (-37 mL/min; P =.01) but increased to baseline after...

  10. Flow measurements in cardiac MRI; Flussmessungen in der kardialen MRT

    Energy Technology Data Exchange (ETDEWEB)

    Lotz, J. [Medizinische Hochschule Hannover, Institut fuer Diagnostische Radiologie, Hannover (Germany)

    2007-04-15

    Phase-contrast flow measurements have become an established method in cardiac MRI. The quantification of intra- and extracardiac shunt volumes as well as the evaluation of valvular disease and aortic coarctation have proved their clinical usefulness. There are some rules that have to be followed when performing and analyzing phase-contrast flow measurements. With these rules in mind, quantitative phase-contrast flow measurements are a reliable and precise method for clinical use of cardiac MRI. (orig.) [German] Flussmessungen gehoeren zum Standardrepertoire der MRT des Herzens. Dabei stehen die Quantifizierungen intra- und extrakardialer Shuntvolumina sowie von Klappenvitien im Vordergrund. Aber auch die Abschaetzung von Stenosen, beispielsweise des Aortenisthmus v. a. ueber einen assoziierten Kollateralfluss, sind klinisch akzeptiert. Bei der Planung und Auswertung einer Phasenkontrastflussmessung muessen einige Regeln beachtet werden, um fehlerhafte Ergebnisse zu vermeiden. Dann aber ist die Phasenkontrastflussmessung eine wertvolle Ergaenzung fuer die taegliche Routine in der Herzbildgebung. (orig.)

  11. Functional Relevance of Coronary Artery Disease by Cardiac Magnetic Resonance and Cardiac Computed Tomography: Myocardial Perfusion and Fractional Flow Reserve

    Directory of Open Access Journals (Sweden)

    Gianluca Pontone

    2015-01-01

    Full Text Available Coronary artery disease (CAD is one of the leading causes of morbidity and mortality and it is responsible for an increasing resource burden. The identification of patients at high risk for adverse events is crucial to select those who will receive the greatest benefit from revascularization. To this aim, several non-invasive functional imaging modalities are usually used as gatekeeper to invasive coronary angiography, but the diagnostic yield of elective invasive coronary angiography remains unfortunately low. Stress myocardial perfusion imaging by cardiac magnetic resonance (stress-CMR has emerged as an accurate technique for diagnosis and prognostic stratification of the patients with known or suspected CAD thanks to high spatial and temporal resolution, absence of ionizing radiation, and the multiparametric value including the assessment of cardiac anatomy, function, and viability. On the other side, cardiac computed tomography (CCT has emerged as unique technique providing coronary arteries anatomy and more recently, due to the introduction of stress-CCT and noninvasive fractional flow reserve (FFR-CT, functional relevance of CAD in a single shot scan. The current review evaluates the technical aspects and clinical experience of stress-CMR and CCT in the evaluation of functional relevance of CAD discussing the strength and weakness of each approach.

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

    Directory of Open Access Journals (Sweden)

    M. Ceccarini

    2014-01-01

    Full Text Available 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.

  13. Risk assessment future cash flows

    OpenAIRE

    Chachina H. G.

    2012-01-01

    This article is about risk assessment in planning future cash flows. Discount rate in DCF-model must include four factors: risk cash flow, inflation, value of investments, turnover assets. This has an influence net present value cash flow and make his incomparable.

  14. Cardiac causes of pulmonary arterial hypertension: assessment with multidetector CT

    Energy Technology Data Exchange (ETDEWEB)

    Hoey, Edward T.D.; Gopalan, Deepa; Agrawal, S.K.B. [Papworth Hospital, Cambridge (United Kingdom); Screaton, Nicholas J. [Papworth Hospital, Cambridge (United Kingdom); Papworth Hospital NHS Trust, Diagnostic Centre, Department of Radiology, Papworth Everard, Cambridgeshire (United Kingdom)

    2009-11-15

    The causes of pulmonary arterial hypertension (PAH) are diverse and include multiple congenital and acquired cardiac diseases as well as diseases primarily affecting the pulmonary vasculature, lung, pleura and chest wall. The traditional role of CT in evaluating PAH includes assessment of pulmonary vasculature and lung parenchyma with limited assessment of the heart. Advances in multidetector CT technology with improved spatial and temporal resolution now permit accurate delineation of cardiac morphology. CT pulmonary angiography (CTPA) is widely utilised in the workup of patients with suspected pulmonary vascular disease and can identify both pulmonary and cardiac causes. As the initial presentation for CTPA is often precipitated by nonspecific, unexplained symptoms and therefore undertaken by a general radiologist, it is important that a systematic approach to the interpretation of these studies, including cardiac evaluation, is routinely adopted. This paper reviews the CT evaluation in pulmonary hypertension with a particular focus on the cardiac causes, their subclassification into congenital systemic to pulmonary shunts and secondary to left heart disease, and their imaging features. It emphasises the use of a systematic approach to interpretation of CTPA examinations both in patients with known PAH and those with previously unsuspected disease. (orig.)

  15. Radionuclide assessment of left ventricular function following cardiac surgery

    Energy Technology Data Exchange (ETDEWEB)

    Howe, W.R.; Jones, R.H.; Sabiston, D.C. Jr.

    1976-01-01

    Use of a high count-rate gamma scintillation camera permits the noninvasive assessment of left ventricular function by nuclear angiocardiography. Counts recorded from the region of the left ventricle at 50- or 100-msec intervals during the first transit of an intravenously administered bolus of radioisotope produce a high-fidelity indicator-dilution curve. Count fluctuations reflect left ventricular volume changes during the cardiac cycle and permit measurement of dv/dt, ejection fraction, mean transit time, and wall motion of this chamber. The present study evaluates (1) the accuracy of this technique compared to standard biplane cineangiography and (2) its usefulness in evaluating patients after cardiac surgery.

  16. Diagnostic Certified Assay: Neuromuscular and Cardiac Assessments

    Directory of Open Access Journals (Sweden)

    Rea Valaperta

    2013-01-01

    Full Text Available The expansion of the specific trinucleotide sequence, [CTG], is the molecular pathological mechanism responsible for the clinical manifestations of DM1. Many studies have described different molecular genetic techniques to detect DM1, but as yet there is no data on the analytical performances of techniques used so far in this disease. We therefore developed and validated a molecular method, “Myotonic Dystrophy SB kit,” to better characterize our DM1 population. 113 patients were examined: 20 DM1-positive, 11 DM1/DM2-negative, and13 DM1-negative/DM2-positive, who had a previous molecular diagnosis, while 69 were new cases. This assay correctly identified 113/113 patients, and all were confirmed by different homemade assays. Comparative analysis revealed that the sensitivity and the specificity of the new kit were very high (>99%. Same results were obtained using several extraction procedures and different concentrations of DNA. The distribution of pathologic alleles showed a prevalence of the “classical” form, while of the 96 nonexpanded alleles 19 different allelic types were observed. Cardiac and neuromuscular parameters were used to clinically characterize our patients and support the new genetic analysis. Our findings suggest that this assay appears to be a very robust and reliable molecular test, showing high reproducibility and giving an unambiguous interpretation of results.

  17. Epidural catheterization in cardiac surgery: The 2012 risk assessment

    Directory of Open Access Journals (Sweden)

    Thomas M Hemmerling

    2013-01-01

    Full Text Available Aims and Objectives: The risk assessment of epidural hematoma due to catheter placement in patients undergoing cardiac surgery is essential since its benefits have to be weighed against risks, such as the risk of paraplegia. We determined the risk of the catheter-related epidural hematoma in cardiac surgery based on the cases reported in the literature up to September 2012. Materials and Methods: We included all reported cases of epidural catheter placement for cardiac surgery in web and in literature from 1966 to September 2012. Risks of other medical and non-medical activities were retrieved from recent reviews or national statistical reports. Results: Based on our analysis the risk of catheter-related epidural hematoma is 1 in 5493 with a 95% confidence interval (CI of 1/970-1/31114. The risk of catheter-related epidural hematoma in cardiac surgery is similar to the risk in the general surgery population at 1 in 6,628 (95% CI 1/1,170-1/37,552. Conclusions: The present risk calculation does not justify not offering epidural analgesia as part of a multimodal analgesia protocol in cardiac surgery.

  18. Automatic assessment of cardiac perfusion MRI

    DEFF Research Database (Denmark)

    Ólafsdóttir, Hildur; Stegmann, Mikkel Bille; Larsson, Henrik B.W.

    2004-01-01

    In this paper, a method based on Active Appearance Models (AAM) is applied for automatic registration of myocardial perfusion MRI. A semi-quantitative perfusion assessment of the registered image sequences is presented. This includes the formation of perfusion maps for three parameters; maximum up...

  19. Interactive Hierarchical-Flow Segmentation of Scar Tissue From Late-Enhancement Cardiac MR Images.

    Science.gov (United States)

    Rajchl, Martin; Yuan, Jing; White, James A; Ukwatta, Eranga; Stirrat, John; Nambakhsh, Cyrus M S; Li, Feng P; Peters, Terry M

    2014-01-01

    We propose a novel multi-region image segmentation approach to extract myocardial scar tissue from 3-D whole-heart cardiac late-enhancement magnetic resonance images in an interactive manner. For this purpose, we developed a graphical user interface to initialize a fast max-flow-based segmentation algorithm and segment scar accurately with progressive interaction. We propose a partially-ordered Potts (POP) model to multi-region segmentation to properly encode the known spatial consistency of cardiac regions. Its generalization introduces a custom label/region order constraint to Potts model to multi-region segmentation. The combinatorial optimization problem associated with the proposed POP model is solved by means of convex relaxation, for which a novel multi-level continuous max-flow formulation, i.e., the hierarchical continuous max-flow (HMF) model, is proposed and studied. We demonstrate that the proposed HMF model is dual or equivalent to the convex relaxed POP model and introduces a new and efficient hierarchical continuous max-flow based algorithm by modern convex optimization theory. In practice, the introduced hierarchical continuous max-flow based algorithm can be implemented on the parallel GPU to achieve significant acceleration in numerics. Experiments are performed in 50 whole heart 3-D LE datasets, 35 with left-ventricular and 15 with right-ventricular scar. The experimental results are compared to full-width-at-half-maximum and Signal-threshold to reference-mean methods using manual expert myocardial segmentations and operator variabilities and the effect of user interaction are assessed. The results indicate a substantial reduction in image processing time with robust accuracy for detection of myocardial scar. This is achieved without the need for additional region constraints and using a single optimization procedure, substantially reducing the potential for error.

  20. Imminent Cardiac Risk Assessment via Optical Intravascular Biochemical Analysis

    Energy Technology Data Exchange (ETDEWEB)

    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

  1. Effects of dopamine infusion on cardiac and renal blood flows in dogs.

    Science.gov (United States)

    Furukawa, Shuji; Nagashima, Yukiko; Hoshi, Katsuichiro; Hirao, Hidehiro; Tanaka, Ryou; Maruo, Kohji; Yamane, Yoshihisa

    2002-01-01

    In veterinary medicine, dopamine is currently being administered clinically by infusion for treatment of kidney disorders at low doses (high doses (> or = 5 microg/kg/min). However, since high doses of dopamine cause peripheral vasoconstriction due to its effect on alpha adrenoceptors, high doses have no longer been recommended. The present study was conducted to explore possible regimens for the use of dopamine infusion in dogs. The regional (renal and cardiac) blood flow for 60 min was measured by using colored microspheres at three doses (3, 10 and 20 microg/kg/min) of dopamine infusion in healthy anesthetized mongrel dogs. The effects on kidney and peripheral hemodynamics at each dose and the resultant cardiac output, mean arterial blood pressure and total peripheral resistance were determined. Renal blood flow increased markedly at 3 microg/kg/min dopamine. Improvement in hemodynamics indicated by marked increase in cardiac blood flow, cardiac output and mean arterial blood pressure and decreased total peripheral resistance was observed at higher doses (10 and 20 microg/kg/min). At 10 microg/kg/min, in addition to the satisfactory increase in cardiac blood flow, there was also a stable satisfactory increase in renal blood flow. However, at 20 microg/kg/min, increased myocardial oxygen consumption (manifested by marked increased in cardiac output), arrythmia and irregular increase in renal blood flow were detected. This study suggests that the clinical use of dopamine infusion in dogs could be safely expanded to moderately higher doses.

  2. Effects of Blood Flow on the Heating of Cardiac Stents Due to Radio Frequency Fields

    OpenAIRE

    Elder, Nate Ian

    2013-01-01

    A safety concern during MRI scans with implanted medical devices is heating induced by the incident RF field. This research was performed to better understand the heating of cardiac stents during MRI. Heating of cardiac stents tends to occur at their ends. The temperature rise will be affected by blood flow through the lumen of the stent. In this work, an experiment was performed to simulate heating of a cardiac stent in the presence of blood flow during exposure to the electric field induced...

  3. In vitro Doppler ultrasound investigation of turbulence intensity in pulsatile flow with simulated cardiac variability.

    Science.gov (United States)

    Thorne, Meghan L; Poepping, Tamie L; Nikolov, Hristo N; Rankin, Richard N; Steinman, David A; Holdsworth, David W

    2009-01-01

    An in vitro investigation of turbulence intensity (TI) associated with a severe carotid stenosis in the presence of physiological cardiac variability is described. The objective of this investigation was to determine if fluctuations due to turbulence could be quantified with conventional Doppler ultrasound (DUS) in the presence of normal physiological cycle-to-cycle cardiac variability. An anthropomorphic model of a 70% stenosed carotid bifurcation was used in combination with a programmable flow pump to generate pulsatile flow with a mean flow rate of 6 mL/s. Utilizing the pump, we studied normal, nonrepetitive cycle-to-cycle cardiac variability (+/-3.9%) in flow, as well as waveform shapes with standard deviations equal to 0, 2 and 3 times the normal variation. Eighty cardiac cycles of Doppler data were acquired at two regions within the model, representing either laminar or turbulent flow; each measurement was repeated six times. Turbulence intensity values were found to be 11 times higher (p laminar region, with a mean difference of 24 cm/s. Twenty cardiac cycles were required for confidence in TI values. In conclusion, these results indicate that it is possible to quantify TI in vitro, even in the presence of normal and exaggerated cycle-to-cycle cardiac variability.

  4. QTc interval in the assessment of cardiac risk

    DEFF Research Database (Denmark)

    Elming, Hanne; Brendorp, Bente; Køber, Lars;

    2002-01-01

    with increased risk of arrhythmias. The paper gives a review of the possibilities to assess the risk of ventricular arrhythmia and/or cardiac death from QTc. Prolonged QTc may hold independent prognostic importance for mortality in common diseases as ischemic heart disease and diabetes mellitus where...... importance in hypertrophic cardiomyopathy or in the arrhythmogenic right ventricular disease. The degree of QTc prolonging during treatment with QTc prolonging drugs is prognostic for the risk of ventricular arrhythmia in form of torsade de pointes and QTc prolonging drugs should probably not be prescribed...

  5. Current status of assessment of fractional flow reserve

    Institute of Scientific and Technical Information of China (English)

    FANG Yi-min; Grisana Grootenhuijs-Triyasut; Pieter A. Doevendans; Yolande Appelman

    2009-01-01

    @@ Coronary angiography presently remains the main method for the diagnosis and instruction of epicardial coronary disease. However, precise characterization of the significance for any given stenosis is limited by the inability to identify intermediate coronary lesions responsible for ischemia.1-3 In clinical practice, in addition to the assessment of the anatomical details of vessel narrowing, a more precise assessment of the impediment to coronary blood flow has become extremely important. At present, several physiological parameters have been introduced to improve discrimination in functional coronary lesion severity during cardiac catheterization.

  6. Automatic Assessment of Socioeconomic Impact on Cardiac Rehabilitation

    Directory of Open Access Journals (Sweden)

    Mireia Calvo

    2013-10-01

    Full Text Available 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 €.

  7. Automatic assessment of socioeconomic impact on cardiac rehabilitation.

    Science.gov (United States)

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

    2013-10-25

    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 €.

  8. Trigeminal cardiac reflex and cerebral blood flow regulation

    Directory of Open Access Journals (Sweden)

    Dominga Lapi

    2016-10-01

    Full Text Available The stimulation of some facial regions is known to trigger the trigemino-cardiac reflex: the main stimulus is represented by the contact of the face with water. This phenomenon called diving reflex induces a set of reactions in the cardiovascular and respiratory systems occurring in all mammals, especially marine (whales, seals. During the immersion of the face in the water, the main responses are aimed at reducing the oxygen consumption of the organism. Accordingly reduction in heart rate, peripheral vasoconstriction, blood pooling in certain organs, especially the heart and brain, and an increase in blood pressure have been reported. Moreover, the speed and intensity of the reflex is inversely proportional to the temperature of the water: more cold the water, more reactions as described are strong. In the case of deep diving an additional effect, such as blood deviation, has been reported: the blood is requested within the lungs, to compensate for the increase in the external pressure, preventing them from collapsing.The trigeminal-cardiac reflex is not just confined to the diving reflex; recently it has been shown that a brief proprioceptive stimulation (10 min by jaw extension in rats produces interesting effects both at systemic and cerebral level, reducing the arterial blood pressure and vasodilating the pial arterioles. The arteriolar dilation is associated with rhythmic diameter changes characterized by an increase in the endothelial activity. Fascinating the stimulation of trigeminal nerve is able to activated the nitric oxide release by vascular endothelial. Therefore the aim of this review was to highlight the effects due to trigeminal cardiac reflex induced by a simple mandibular extension, because produced opposite effects compared to those elicited by the diving reflex as it induces hypotension and modulation of cerebral arteriolar tone.

  9. Trigeminal Cardiac Reflex and Cerebral Blood Flow Regulation

    Science.gov (United States)

    Lapi, Dominga; Scuri, Rossana; Colantuoni, Antonio

    2016-01-01

    The stimulation of some facial regions is known to trigger the trigemino-cardiac reflex: the main stimulus is represented by the contact of the face with water. This phenomenon called diving reflex induces a set of reactions in the cardiovascular and respiratory systems occurring in all mammals, especially marine (whales, seals). During the immersion of the face in the water, the main responses are aimed at reducing the oxygen consumption of the organism. Accordingly reduction in heart rate, peripheral vasoconstriction, blood pooling in certain organs, especially the heart, and brain and an increase in blood pressure have been reported. Moreover, the speed and intensity of the reflex is inversely proportional to the temperature of the water: more cold the water, more reactions as described are strong. In the case of deep diving an additional effect, such as blood deviation, has been reported: the blood is sequestered within the lungs, to compensate for the increase in the external pressure, preventing them from collapsing. The trigeminal-cardiac reflex is not just confined to the diving reflex; recently it has been shown that a brief proprioceptive stimulation (10 min) by jaw extension in rats produces interesting effects both at systemic and cerebral levels, reducing the arterial blood pressure, and vasodilating the pial arterioles. The arteriolar dilation is associated with rhythmic diameter changes characterized by an increase in the endothelial activity. Fascinating the stimulation of trigeminal nerve is able to activate the nitric oxide release by vascular endothelial cells. Therefore, the aim of this review was to highlight the effects due to trigeminal cardiac reflex induced by a simple mandibular extension. Opposite effects, such as hypotension, and modulation of cerebral arteriolar tone, were observed, when these responses were compared to those elicited by the diving reflex. PMID:27812317

  10. Scintigraphic assessment of cardiac sympathetic innervation with I-123-metaiodobenzylguanidine in cardiomyopathy. Special reference to cardiac arrhythmia

    Energy Technology Data Exchange (ETDEWEB)

    Asano, Takahisa; Otsuka, Nobuaki; Sone, Teruki; Mimura, Hiroaki; Yanagimoto, Shinichi; Tomomitsu, Tatsushi; Fukunaga, Masao [Kawasaki Medical School, Kurashiki, Okayama (Japan); Morita, Koichi

    1999-07-01

    Cardiac sympathetic imagings with I-123-metaiodobenzylguanidine (MIBG) were carried out in 5 cases with dilated cardiomyopathy (DCM), 26 cases with hypertrophic cardiomyopathy (HCM), and 4 cases without cardiac disease as a control to assess cardiac sympathetic innervation qualitatively and quantitatively, and to clarify the relation of MIBG accumulation to arrhythmia. MIBG scintigraphy was performed at 15 min. (early image) and 4 hr. (delayed image) after intravenous injection of MIBG 111 MBq. The MIBG uptake ratio of mediastinum (H/M) and the cardiac washout rate (WR) from early to delayed images were calculated. On both early and delayed SPECTs, MIBG uptake was assessed by defect scores (DSs). Regarding the cases with HCM, the MIBG uptake ratio, WR, and DS were also compared in cases with and without arrhythmia. In DCM, the MIBG uptake on delayed SPECT was markedly low, the H/M ratio was significantly lower, and the DS was significantly higher than in the control (all p<0.05). As for the WR, there was no significant difference between HCM, DCM and the control. In HCM, significantly reduced MIBG uptake was observed in cases with ventricular techycardia (VT) and in cases with atrial fibrillation (Af), as compared with cases without arrhythmia (all p<0.05). There results suggest that MIBG scintigraphy might be a useful tool in the assessment of cardiac sympathetic abnormalities in cardiomyopathy, especially in cases with arrhythmia. (author)

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  13. The coronary slow flow phenomenon: a new cardiac "Y" syndrome?

    Science.gov (United States)

    Leone, Maria Cristina; Gori, Tommaso; Fineschi, Massimo

    2008-01-01

    The coronary slow flow phenomenon (CSFP) is an angiographic finding that is characterised by delayed progression of the contrast medium during coronary angiography. The mechanism of this phenomenon remains unknown. In the present paper, we revise the current evidence regarding this phenomenon and discuss recent findings from our group reporting increased resting resistances in patients with the CSFP. We report that these patients had preserved blood flow responses to the intracoronary infusion of the vasodilator papaverine, demonstrating that the CSFP is not necessarily associated with an abnormal coronary flow reserve. Based on these findings and on the review of the current literature, we concur with the concept proposed by Beltrame et al. that the CSFP should be considered a separate clinical entity. Further studies are necessary to describe the clinical characteristics, including the prognosis, of these patients and to identify potential treatments.

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

    Science.gov (United States)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    Nillesen, M M; Lopata, R G P; Gerrits, I H; Thijssen, J M; De Korte, C L [Clinical Physics Laboratory-833, Department of Pediatrics, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands); De Boode, W P [Neonatology, Department of Pediatrics, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands); Huisman, H J [Department of Radiology, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands); Kapusta, L [Pediatric Cardiology, Department of Pediatrics, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands)], E-mail: m.m.nillesen@cukz.umcn.nl

    2009-04-07

    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

  16. Probing cardiac repolarization reserve in drug safety assessment

    NARCIS (Netherlands)

    Nalos, L.

    2011-01-01

    Excessive prolongation of cardiac repolarization, manifested as QT prolongation on ECG, is common unwanted side effect of many drugs and drug candidates. Prolongation of QT interval may lead to life threatening cardiac arrhythmia – Torsade de Point (TdP). Number of drugs was withdrawn from the marke

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

    Science.gov (United States)

    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 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

  18. Cardiac abnormalities assessed by non-invasive techniques in patients with newly diagnosed idiopathic inflammatory myopathies

    DEFF Research Database (Denmark)

    Diederichsen, Louise Pyndt; Simonsen, Jane Angel; Diederichsen, Axel Cosmus Pyndt;

    2015-01-01

    , cardiac troponin-I (TnI), electrocardiogram (standard 12-lead and 48-h Holter monitoring), echocardiography with tissue Doppler measures, cardiac magnetic resonance (CMR) imaging with T2 mapping and semi-quantitative (99m)technetium pyrophosphate ((99m)Tc-PYP) scintigraphy. RESULTS: Dyspnoea was present....... The myocardial (99m)Tc-PYP uptake and CMR results differed between patients and controls, albeit not with statistical significance. Overall, cardiac abnormalities were demonstrated in 9 (64%) of the patients versus 2 (14%) of the controls (p=0.02). CONCLUSIONS: Cardiac abnormalities assessed by TnI, ECG...

  19. Reduced peripheral arterial blood flow with preserved cardiac output during submaximal bicycle exercise in elderly heart failure

    Directory of Open Access Journals (Sweden)

    Leng Xiaoyan

    2009-11-01

    Full Text Available Abstract Background Older heart failure (HF patients exhibit exercise intolerance during activities of daily living. We hypothesized that reduced lower extremity blood flow (LBF due to reduced forward cardiac output would contribute to submaximal exercise intolerance in older HF patients. Methods and Results Twelve HF patients both with preserved and reduced left ventricular ejection fraction (LVEF (aged 68 ± 10 years without large (aorta or medium sized (iliac or femoral artery vessel atherosclerosis, and 13 age and gender matched healthy volunteers underwent a sophisticated battery of assessments including a peak exercise oxygen consumption (peak VO2, b physical function, c cardiovascular magnetic resonance (CMR submaximal exercise measures of aortic and femoral arterial blood flow, and d determination of thigh muscle area. Peak VO2 was reduced in HF subjects (14 ± 3 ml/kg/min compared to healthy elderly subjects (20 ± 6 ml/kg/min (p = 0.01. Four-meter walk speed was 1.35 ± 0.24 m/sec in healthy elderly verses 0.98 ± 0.15 m/sec in HF subjects (p p ≤ 0.03. Conclusion During CMR submaximal bike exercise in the elderly with heart failure, mechanisms other than low cardiac output are responsible for reduced lower extremity blood flow.

  20. PIE Nacelle Flow Analysis and TCA Inlet Flow Quality Assessment

    Science.gov (United States)

    Shieh, C. F.; Arslan, Alan; Sundaran, P.; Kim, Suk; Won, Mark J.

    1999-01-01

    This presentation includes three topics: (1) Analysis of isolated boattail drag; (2) Computation of Technology Concept Airplane (TCA)-installed nacelle effects on aerodynamic performance; and (3) Assessment of TCA inlet flow quality.

  1. QUALITY OF LIFE ASSESSMENT IN CARDIAC TRANSPLANT RECIPIENTS

    Directory of Open Access Journals (Sweden)

    A. O. Shevchenko

    2014-01-01

    Full Text Available Background. Quality of life (QoL is an important criterion for the treatment effi cacy that provides an important data regarding patient’s personal estimation of social adaptation and ability to perform daily duties.Methods. The study was aimed to evaluate QoL in cardiac transplant recipients. We have enrolled 42 stage D heart failure patients aged 29–61 (mean 39,23 ± 12,31 y/o, 38 males and 4 females, survived cardiac transplant surgery between Jan 2008 and Jan 2013. QoL was evaluated using the SF-36 survey prior to the heart surgery and during the follow-up period up to the 5 years.Results. Pre-operative assessment revealed low QoL indices of physical activity as well as general health status. Follow-up showed dramatic improvement in all QoL measures during 1 year after the surgery which was consistent through the whole observation period. There was an increase in physical functioning index by 2,8 times (p < 0,01, physical status dependent role functioning by 14 times (р < 0,0001, emotional status dependent role functioning by 3 times (р = 0,02, social functioning by 4,8 times (p = 0,002, pain threshold by 3 times (p = 0,02, psychic health by 3,6 times (p = 0,001, life activity by 2,6 times(p = 0,003, and total health by 1,6 times (p = 0,03. Physical activity was restored in 90% of patients during the fi rst year.Conclusion. The study shows signifi cant improvement in all QoL variables after heart transplantation in stage D heart failure patients. Main indices of physical, psychical, and social activities rise at the fi rst year and remain high during the 5-year period. These data support heart transplantation as a radical and effective method of terminal heart failure treatment.

  2. Exploration EVA Purge Flow Assessment

    Science.gov (United States)

    Navarro, Moses; Conger, Bruce; Campbell, Colin

    2011-01-01

    An advanced future spacesuit will require properly sized suit and helmet purge flow rates in order to sustain a crew member with a failed Portable Life Support System (PLSS) during an Extravehicular Activity (EVA). A computational fluid dynamics evaluation was performed to estimate the helmet purge flow rate required to washout carbon dioxide and to prevent the condensing ("fogging") of water vapor on the helmet visor. An additional investigation predicted the suit purge flow rate required to provide sufficient convective cooling to keep the crew member comfortable. This paper summarizes the results of these evaluations.

  3. Noninvasive Physiologic Assessment of Coronary Stenoses Using Cardiac CT

    Directory of Open Access Journals (Sweden)

    Lei Xu

    2015-01-01

    Full Text Available 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.

  4. Cardiac imaging for the assessment of patients being evaluated for kidney or liver transplantation.

    Science.gov (United States)

    Parikh, Kalindi; Appis, Andrew; Doukky, Rami

    2015-04-01

    Cardiac risk assessment prior to kidney and liver transplantation is controversial. Given the paucity of available organs, selecting appropriate recipients with favorable short- and long-term cardiovascular risk profile is crucial. Using noninvasive cardiac imaging tools to guide cardiovascular risk assessment and management can also be challenging and controversial. In this article, we address the burden of coronary artery disease among kidney and liver transplant candidates and review the literature pertaining to the diagnostic accuracy and the prognostic value of noninvasive cardiac imaging techniques in this population.

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

    Science.gov (United States)

    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.

  6. Cine magnetic resonance imaging for evaluation of cardiac structure and flow dynamics in congenital heart disease

    Energy Technology Data Exchange (ETDEWEB)

    Akagi, Teiji; Kiyomatsu, Yumi; Ohara, Nobutoshi; Takagi, Junichi; Sato, Noboru; Kato, Hirohisa (Kurume Univ., Fukuoka (Japan). School of Medicine); Eto, Takaharu

    1989-10-01

    Cine magnetic resonance imaging (Cine MRI) was performed in 20 patients aged 19 days to 13 years (mean 4.0 years), who had congenital heart disease confirmed at echocardiography or angiography. Prior to cine MRI, gated MRI was performed to evaluate for cardiac structure. Cine MRI was demonstrated by fast low fip angle shot imaging technique with a 30deg flip angle, 15 msec echo time, 30-40 msec pulse repetition time, and 128 x 128 acquisition matrix. Abnormalities of cardiac structure were extremely well defined in all patients by gated MRI. Intracardiac or intravascular blood flow were visualized in 17 (85%) of 20 patients by cine MRI. Left to right shunt flow through ventricular septal defect, atrial septal defect, and endocardial cushion defect were visualized with low signal intensity area. Low intensity jets flow through the site of re-coarctation of the aorta were also visualized. However, the good recording of cine MRI was not obtained because of artifacts in 3 of 20 patients (15%) who had severe congestive heart failure or respiratory arrhythmia. Gated MRI provides excellent visualization of fine structure, and cine MRI can provide high spatial resolution imaging of flow dynamic in a variety of congenital heart disease, noninvasively. (author).

  7. In situ cardiac perfusion reveals interspecific variation of intraventricular flow separation in reptiles.

    Science.gov (United States)

    Joyce, William; Axelsson, Michael; Altimiras, Jordi; Wang, Tobias

    2016-07-15

    The ventricles of non-crocodilian reptiles are incompletely divided and provide an opportunity for mixing of oxygen-poor blood and oxygen-rich blood (intracardiac shunting). However, both cardiac morphology and in vivo shunting patterns exhibit considerable interspecific variation within reptiles. In the present study, we develop an in situ double-perfused heart approach to characterise the propensity and capacity for shunting in five reptile species: the turtle Trachemys scripta, the rock python Python sebae, the yellow anaconda Eunectes notaeus, the varanid lizard Varanus exanthematicus and the bearded dragon Pogona vitticeps To simulate changes in vascular bed resistance, pulmonary and systemic afterloads were independently manipulated and changes in blood flow distribution amongst the central outflow tracts were monitored. As previously demonstrated in Burmese pythons, rock pythons and varanid lizards exhibited pronounced intraventricular flow separation. As pulmonary or systemic afterload was raised, flow in the respective circulation decreased. However, flow in the other circulation, where afterload was constant, remained stable. This correlates with the convergent evolution of intraventricular pressure separation and the large intraventricular muscular ridge, which compartmentalises the ventricle, in these species. Conversely, in the three other species, the pulmonary and systemic flows were strongly mutually dependent, such that the decrease in pulmonary flow in response to elevated pulmonary afterload resulted in redistribution of perfusate to the systemic circuit (and vice versa). Thus, in these species, the muscular ridge appeared labile and blood could readily transverse the intraventricular cava. We conclude that relatively minor structural differences between non-crocodilian reptiles result in the fundamental changes in cardiac function. Further, our study emphasises that functionally similar intracardiac flow separation evolved independently in

  8. Early embryonic intra-cardiac flow fields at three idealized ventricular morphologies

    Science.gov (United States)

    Pekkan, Kerem; Jamaly, Mohammad; Kara, Burak; Keller, Bradley; Sotiropoulos, Fotis

    2009-11-01

    Pulsatile 3D multiple inlet/outlet flow within tiny (100-300μm dia) embryonic ventricles feature distinct intra-cardiac flow streams whose role in regulating the morphogenesis of spiral aorto-pulmonary septum has long been debated. The low Re number flow regimes limit mixing of these streams as replicated in our flow-visualization experiments with chick embryos. A state-of-the art high-resolution immersed boundary CFD solver which was developed for complex patient-specific cardiovascular internal flow problems is applied and optimized for this problem. Idealized tubular ventricles at 3 major embryonic stages (straight, C- and D- loops) are created by our sketch-based anatomical editing tool. CFD results are validated with PIV measurements acquired from a micro-fabricated C-loop stage replica and in vivo flow vis data from confocal microscopy. This model provided the inlet velocity profile for arterial models and flow fields at the inner curvature of embryonic hearts for different ventricular topologies are compared for off-design modes.

  9. Determinants of Left Ventricular Mass and Hypertrophy in Hemodialysis Patients Assessed by Cardiac Magnetic Resonance Imaging

    OpenAIRE

    Patel, Rajan K.; Oliver, Scott; Mark, Patrick B.; Powell, Joanna R.; Emily P. McQuarrie; Traynor, James P.; Dargie, Henry J.; Jardine, Alan G.

    2009-01-01

    Background and objectives: Left ventricular hypertrophy (LVH) is an independent risk factor for premature cardiovascular death in hemodialysis (HD) patients and one of the three forms of uremic cardiomyopathy. Cardiovascular magnetic resonance (CMR) is a volume-independent technique to assess cardiac structure. We used CMR to assess the determinants of left ventricular mass (LVM) and LVH in HD patients.

  10. Assessment of cardiac output with transpulmonary thermodilution during exercise in humans

    DEFF Research Database (Denmark)

    Calbet, José A L; Boushel, Robert

    2015-01-01

    The accuracy and reproducibility of transpulmonary thermodilution (TPTd) to assess cardiac output (Q̇) in exercising men was determined using indocyanine green (ICG) dilution as a reference method. TPTd has been utilized for the assessment of Q̇ and preload indexes of global end-diastolic volume...

  11. Debris flows: behavior and hazard assessment

    Science.gov (United States)

    Iverson, Richard M.

    2014-01-01

    Debris flows are water-laden masses of soil and fragmented rock that rush down mountainsides, funnel into stream channels, entrain objects in their paths, and form lobate deposits when they spill onto valley floors. Because they have volumetric sediment concentrations that exceed 40 percent, maximum speeds that surpass 10 m/s, and sizes that can range up to ~109 m3, debris flows can denude slopes, bury floodplains, and devastate people and property. Computational models can accurately represent the physics of debris-flow initiation, motion and deposition by simulating evolution of flow mass and momentum while accounting for interactions of debris' solid and fluid constituents. The use of physically based models for hazard forecasting can be limited by imprecise knowledge of initial and boundary conditions and material properties, however. Therefore, empirical methods continue to play an important role in debris-flow hazard assessment.

  12. An Immersed Boundary Finite-Element Solver for Flow-Induced Deformation of Soft Structures with Application in Cardiac Flows

    Science.gov (United States)

    Bhardwaj, Rajneesh; Mittal, Rajat

    2011-11-01

    The modeling of complex biological phenomena such as cardiac mechanics is challenging. It involves complex three dimensional geometries, moving structure boundaries inside the fluid domain and large flow-induced deformations of the structure. We present a fluid-structure interaction solver (FSI) which couples a sharp-interface immersed boundary method for flow simulation with a powerful finite-element based structure dynamics solver. An implicit partitioned (or segregated) approach is implemented to ensure the stability of the solver. We validate the FSI solver with published benchmark for a configuration which involves a thin elastic plate attached to a rigid cylinder. The frequency and amplitude of the oscillations of the plate are in good agreement with published results and non-linear dynamics of the plate and its coupling with the flow field are discussed. The FSI solver is used to understand left-ventricular hemodynamics and flow-induced dynamics of mitral leaflets during early diastolic filling and results from this study are presented.

  13. Multisite Tissue Oxygenation Monitoring Indicates Organ-Specific Flow Distribution and Oxygen Delivery Related to Low Cardiac Output in Preterm Infants With Clinical Sepsis

    NARCIS (Netherlands)

    van der Laan, Michelle E.; Roofthooft, Marcus T. R.; Fries, Marian W. A.; Schat, Trijntje E.; Bos, Arend F.; Berger, Rolf M. F.; Kooi, Elisabeth M. W.

    2016-01-01

    Objectives: Cardiac output may be compromised in preterm infants with sepsis. Whether low cardiac output is associated with low tissue oxygen supply in these patients is unclear. The aim of the current study was to assess the association between cardiac output, assessed by echocardiography, and tiss

  14. Impact of pacing modality and biventricular pacing on cardiac output and coronary conduit flow in the post-cardiotomy patient.

    LENUS (Irish Health Repository)

    Healy, David G

    2012-02-03

    We have previously demonstrated the role of univentricular pacing modalities in influencing coronary conduit flow in the immediate post-operative period in the cardiac surgery patient. We wanted to determine the mechanism of this improved coronary conduit and, in addition, to explore the possible benefits with biventricular pacing. Sixteen patients undergoing first time elective coronary artery bypass grafting who required pacing following surgery were recruited. Comparison of cardiac output and coronary conduit flow was performed between VVI and DDD pacing with a single right ventricular lead and biventricular pacing lead placement. Cardiac output was measured using arterial pulse waveform analysis while conduit flow was measured using ultrasonic transit time methodology. Cardiac output was greatest with DDD pacing using right ventricular lead placement only [DDD-univentricular 5.42 l (0.7), DDD-biventricular 5.33 l (0.8), VVI-univentricular 4.71 l (0.8), VVI-biventricular 4.68 l (0.6)]. DDD-univentricular pacing was significantly better than VVI-univentricular (P=0.023) and VVI-biventricular pacing (P=0.001) but there was no significant advantage to DDD-biventricular pacing (P=0.45). In relation to coronary conduit flow, DDD pacing again had the highest flow [DDD-univentricular 55 ml\\/min (24), DDD-biventricular 52 ml\\/min (25), VVI-univentricular 47 ml\\/min (23), VVI-biventricular 50 ml\\/min (26)]. DDD-univentricular pacing was significantly better than VVI-univentricular (P=0.006) pacing but not significantly different to VVI-biventricular pacing (P=0.109) or DDD-biventricular pacing (P=0.171). Pacing with a DDD modality offers the optimal coronary conduit flow by maximising cardiac output. Biventricular lead placement offered no significant benefit to coronary conduit flow or cardiac output.

  15. Evaluation of coronary blood flow velocity during cardiac arrest with circulation maintained through mechanical chest compressions in a porcine model

    Directory of Open Access Journals (Sweden)

    Wagner Henrik

    2011-12-01

    Full Text Available Abstract Background Mechanical chest compressions (CCs have been shown capable of maintaining circulation in humans suffering cardiac arrest for extensive periods of time. Reports have documented a visually normalized coronary blood flow during angiography in such cases (TIMI III flow, but it has never been actually measured. Only indirect measurements of the coronary circulation during cardiac arrest with on-going mechanical CCs have been performed previously through measurement of the coronary perfusion pressure (CPP. In this study our aim was to correlate average peak coronary flow velocity (APV to CPP during mechanical CCs. Methods In a closed chest porcine model, cardiac arrest was established through electrically induced ventricular fibrillation (VF in eleven pigs. After one minute, mechanical chest compressions were initiated and then maintained for 10 minutes upon which the pigs were defibrillated. Measurements of coronary blood flow in the left anterior descending artery were made at baseline and during VF with a catheter based Doppler flow fire measuring APV. Furthermore measurements of central (thoracic venous and arterial pressures were also made in order to calculate the theoretical CPP. Results Average peak coronary flow velocity was significantly higher compared to baseline during mechanical chests compressions and this was observed during the entire period of mechanical chest compressions (12 - 39% above baseline. The APV slowly declined during the 10 min period of mechanical chest compressions, but was still higher than baseline at the end of mechanical chest compressions. CPP was simultaneously maintained at > 20 mmHg during the 10 minute episode of cardiac arrest. Conclusion Our study showed good correlation between CPP and APV which was highly significant, during cardiac arrest with on-going mechanical CCs in a closed chest porcine model. In addition APV was even higher during mechanical CCs compared to baseline. Mechanical

  16. Combination of principal component analysis and optical-flow motion compensation for improved cardiac MR thermometry

    Science.gov (United States)

    Toupin, S.; de Senneville, B. Denis; Ozenne, V.; Bour, P.; Lepetit-Coiffe, M.; Boissenin, M.; Jais, P.; Quesson, B.

    2017-02-01

    The use of magnetic resonance (MR) thermometry for the monitoring of thermal ablation is rapidly expanding. However, this technique remains challenging for the monitoring of the treatment of cardiac arrhythmia by radiofrequency ablation due to the heart displacement with respiration and contraction. Recent studies have addressed this problem by compensating in-plane motion in real-time with optical-flow based tracking technique. However, these algorithms are sensitive to local variation of signal intensity on magnitude images associated with tissue heating. In this study, an optical-flow algorithm was combined with a principal component analysis method to reduce the impact of such effects. The proposed method was integrated to a fully automatic cardiac MR thermometry pipeline, compatible with a future clinical workflow. It was evaluated on nine healthy volunteers under free breathing conditions, on a phantom and in vivo on the left ventricle of a sheep. The results showed that local intensity changes in magnitude images had lower impact on motion estimation with the proposed method. Using this strategy, the temperature mapping accuracy was significantly improved.

  17. Coronary grafts flow and cardiac pacing modalities: how to improve perioperative myocardial perfusion.

    LENUS (Irish Health Repository)

    D'Ancona, Giuseppe

    2012-02-03

    OBJECTIVE: Aim of this study was to investigate modifications of coronary grafts flow during different pacing modalities after CABG. MATERIALS AND METHODS: Two separate prospective studies were conducted in patients undergoing CABG and requiring intraoperative epicardial pacing. In a first study (22 patients) coronary grafts flows were measured during dual chamber pacing (DDD) and during ventricular pacing (VVI). In a second study (10 patients) flows were measured during DDD pacing at different atrio-ventricular (A-V) delay periods. A-V delay was adjusted in 25 ms increments from 25 to 250 ms and flow measurements were performed for each A-V delay increment. A transit time flowmeter was used for the measurements. RESULTS: An average of 3.4 grafts\\/patient were performed. In the first study, average coronary graft flow was 47.4+\\/-20.8 ml\\/min during DDD pacing and 41.8+\\/-18.2 ml\\/min during VVI pacing (P = 0.0004). Furthermore average systolic pressure was 94.3+\\/-10.1 mmHg during DDD pacing and 89.6+\\/-12.2 mmHg during VVV pacing (P = 0.0007). No significant differences in diastolic pressure were recorded during the two different pacing modalities. In the second study, maximal flows were achieved during DDD pacing with an A-V delay of 175 ms (54+\\/-9.6 ml\\/min) and minimal flows were detected at 25 ms A-V delay (38.1+\\/-4.7 ml\\/min) (P=ns). No significant differences in systolic or diastolic blood pressure were noticed during the different A-V delays. CONCLUSION: Grafts flowmetry provides an extra tool to direct supportive measures such as cardiac pacing after CABG. DDD mode with A-V delay around 175 ms. should be preferred to allow for maximal myocardial perfusion via the grafts.

  18. Pulmonary intravascular blood volume changes through the cardiac cycle in healthy volunteers studied by cardiovascular magnetic resonance measurements of arterial and venous flow

    Directory of Open Access Journals (Sweden)

    Arheden Hakan

    2009-10-01

    Full Text Available Abstract Background This study aims to present a novel method for using cardiovascular magnetic resonance (CMR to non-invasively quantify the variation in pulmonary blood volume throughout the cardiac cycle in humans. Methods 10 healthy volunteers (7 males, 3 female, age range 21-32 years were studied. The blood flow in the pulmonary artery and all pulmonary veins was quantified during free breathing using phase contrast velocity encoded CMR. The difference in flow between the pulmonary artery and the pulmonary veins was integrated to calculate the change in pulmonary blood volume throughout the cardiac cycle. Results The stroke volumes in the pulmonary artery and the sum of the pulmonary veins were (mean ± SEM 103 ± 6 ml and 95 ± 6 ml, respectively. The pulmonary blood volume variation (PBVV was 48 ± 5 ml, and the PBVV expressed as percent of the pulmonary artery stroke volume was 46 ± 3%. The maximum increase in pulmonary blood volume occurred 310 ± 12 ms after the R-wave from the ECG (32 ± 2% of the cardiac cycle. PBVV did not correlate to change in cross-sectional area in the pulmonary artery (R2 = 0.03, p = 0.66. Conclusion It is feasible to non-invasively quantify the change in pulmonary blood volume during the cardiac cycle in humans using CMR. The average pulmonary blood volume variation in healthy volunteers was approximately 50 ml and this was approximately 50% of the stroke volume. Further studies are needed to assess the utility of the pulmonary blood volume variation as a measure for identifying cardiac and pulmonary vascular disease.

  19. Performance of automated software in the assessment of segmental left ventricular function in cardiac CT: Comparison with cardiac magnetic resonance

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Rui [Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston, SC (United States); Capital Medical University, Department of Radiology, Beijing Anzhen Hospital, Beijing (China); Meinel, Felix G. [Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston, SC (United States); Ludwig-Maximilians-University Hospital, Institute for Clinical Radiology, Munich (Germany); Schoepf, U.J. [Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston, SC (United States); Medical University of South Carolina, Division of Cardiology, Department of Medicine, Charleston, SC (United States); Canstein, Christian [Siemens Medical Solutions USA, Malvern, PA (United States); Spearman, James V. [Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston, SC (United States); De Cecco, Carlo N. [Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston, SC (United States); University of Rome ' ' Sapienza' ' , Departments of Radiological Sciences, Oncology and Pathology, Latina (Italy)

    2015-12-15

    To evaluate the accuracy, reliability and time saving potential of a novel cardiac CT (CCT)-based, automated software for the assessment of segmental left ventricular function compared to visual and manual quantitative assessment of CCT and cardiac magnetic resonance (CMR). Forty-seven patients with suspected or known coronary artery disease (CAD) were enrolled in the study. Wall thickening was calculated. Segmental LV wall motion was automatically calculated and shown as a colour-coded polar map. Processing time for each method was recorded. Mean wall thickness in both systolic and diastolic phases on polar map, CCT, and CMR was 9.2 ± 0.1 mm and 14.9 ± 0.2 mm, 8.9 ± 0.1 mm and 14.5 ± 0.1 mm, 8.3 ± 0.1 mm and 13.6 ± 0.1 mm, respectively. Mean wall thickening was 68.4 ± 1.5 %, 64.8 ± 1.4 % and 67.1 ± 1.4 %, respectively. Agreement for the assessment of LV wall motion between CCT, CMR and polar maps was good. Bland-Altman plots and ICC indicated good agreement between CCT, CMR and automated polar maps of the diastolic and systolic segmental wall thickness and thickening. The processing time using polar map was significantly decreased compared with CCT and CMR. Automated evaluation of segmental LV function with polar maps provides similar measurements to manual CCT and CMR evaluation, albeit with substantially reduced analysis time. (orig.)

  20. Echocardiographic Assessment of Degenerative Mitral Stenosis: A Diagnostic Challenge of an Emerging Cardiac Disease.

    Science.gov (United States)

    Oktay, Ahmet Afşşin; Gilliland, Yvonne E; Lavie, Carl J; Ramee, Stephen J; Parrino, Patrick E; Bates, Michael; Shah, Sangeeta; Cash, Michael E; Dinshaw, Homeyar; Qamruddin, Salima

    2017-03-01

    Degenerative mitral stenosis (DMS) is characterized by decreased mitral valve (MV) orifice area and increased transmitral pressure gradient due to chronic noninflammatory degeneration and subsequent calcification of the fibrous mitral annulus and the MV leaflets. The "true" prevalence of DMS in the general population is unknown. DMS predominantly affects elderly individuals, many of whom have multiple other comorbidities. Transcatheter MV replacement techniques, although their long-term outcomes are yet to be tested, have been gaining popularity and may emerge as more effective and relatively safer treatment option for patients with DMS. Echocardiography is the primary imaging modality for evaluation of DMS and related hemodynamic abnormalities such as increased transmitral pressure gradient and pulmonary arterial pressure. Classic echocardiographic techniques used for evaluation of mitral stenosis (pressure half time, proximal isovelocity surface area, continuity equation, and MV area planimetry) lack validation for DMS. Direct planimetry with 3-dimensional echocardiography and color flow Doppler is a reasonable technique for determining MV area in DMS. Cardiac computed tomography is an essential tool for planning potential interventions or surgeries for DMS. This article reviews the current concepts on mitral annular calcification and its role in DMS. We then discuss the epidemiology, natural history, differential diagnosis, mechanisms, and echocardiographic assessment of DMS.

  1. Cardiac Imaging for Assessing Low-Gradient Severe Aortic Stenosis.

    Science.gov (United States)

    Clavel, Marie-Annick; Burwash, Ian G; Pibarot, Philippe

    2017-02-01

    Up to 40% of patients with aortic stenosis (AS) harbor discordant Doppler-echocardiographic findings, the most common of which is the presence of a small aortic valve area (≤1.0 cm(2)) suggesting severe AS, but a low gradient (<40 mm Hg) suggesting nonsevere AS. The purpose of this paper is to present the role of multimodality imaging in the diagnostic and therapeutic management of this challenging entity referred to as low-gradient AS. Doppler-echocardiography is critical to determine the subtype of low-gradient AS: that is, classical low-flow, paradoxical low-flow, or normal-flow. Patients with low-flow, low-gradient AS generally have a worse prognosis compared with patients with high-gradient or with normal-flow, low-gradient AS. Patients with low-gradient AS and evidence of severe AS benefit from aortic valve replacement (AVR). However, confirmation of the presence of severe AS is particularly challenging in these patients and requires a multimodality imaging approach including low-dose dobutamine stress echocardiography and aortic valve calcium scoring by multidetector computed tomography. Transcatheter AVR using a transfemoral approach may be superior to surgical AVR in patients with low-flow, low-gradient AS. Further studies are needed to confirm the best valve replacement procedure and prosthetic valve for each category of low-gradient AS and to identify patients with low-gradient AS in whom AVR is likely to be futile.

  2. Cardiac abnormalities assessed by non-invasive techniques in patients with newly diagnosed idiopathic inflammatory myopathies

    DEFF Research Database (Denmark)

    Diederichsen, Louise Pyndt; Simonsen, Jane Angel; Diederichsen, Axel Cosmus Pyndt

    2015-01-01

    inflammatory myopathies (IIM) by means of non-invasive techniques. METHODS: Fourteen patients with IIM (8 polymyositis, 4 dermatomyositis, 2 cancer-associated dermatomyositis) and 14 gender- and age- matched healthy control subjects were investigated. Participant assessments included a cardiac questionnaire...

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

    Science.gov (United States)

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

    2014-08-01

    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

  4. The utility of cardiac CT beyond the assessment of suspected coronary artery disease

    Energy Technology Data Exchange (ETDEWEB)

    Kakouros, N. [Johns Hopkins Hospital, Baltimore, MD (United States); Giles, J.; Crundwell, N.B. [Conquest Hospital, St Leonards-on-Sea, East Sussex (United Kingdom); McWilliams, E.T.M., E-mail: eric.mcwilliams@esht.nhs.uk [Conquest Hospital, St Leonards-on-Sea, East Sussex (United Kingdom)

    2012-07-15

    Extensive work has been done over recent years to improve the spatial and temporal resolution of electrocardiogram (ECG)-gated cardiac computed tomography (CT). Advances in both hardware and software analysis have enabled the development of non-invasive coronary angiography. However, these high-quality examinations lend themselves to multiple additional applications beyond coronary angiography. In this review, we illustrate and discuss some established and some emerging applications of ECG-gated cardiac CT beyond the assessment of suspected coronary disease, particularly in light of recent recommendations on the appropriate use of this technology.

  5. ASSESSMENT OF SELECTED CARDIAC FUNCTIONS OF SPORTSPERSON OF VADODARA CITY

    Directory of Open Access Journals (Sweden)

    Rachit Joshi

    2012-02-01

    Full Text Available Aims and objective: Sports activity had always been an epitome of physical fitness activities. Multiple studies have shown that people, who maintain appropriate body fitness, using judicious regimens of exercise and weight control, have the additional benefit of prolonged life. The aim of this study was to find out and confirm the fact that regular exercise or sports activity have a beneficial effect on the various system of our body especially the cardiovascular system. Methodology: A comparative study was carried out at IPCL sports complex of Vadodara city in between the sportsperson and control persons using unpaired ‘t’ test for resting heart rate and blood pressure. They were subjected to hopping test: following which the maximum heart rate achieved and time taken for recovery to resting heart rate was measured. Results: As a result of our study we came to know that sportsperson have a significantly lower resting heart rate; lower maximum heart rate achieved and a reduced recovery time after hopping test than sedentary individuals. Conclusion: Our study reaffirms the fact that regular physical activity in any form slows the rate of decline with age of most of the physiological parameters that we associate with health and fitness especially by decline in basal heart rate and increased cardiac reserves. [National J of Med Res 2012; 2(1.000: 47-50

  6. Valveless pumping mechanics of the embryonic heart during cardiac looping: Pressure and flow through micro-PIV.

    Science.gov (United States)

    Bark, D L; Johnson, B; Garrity, D; Dasi, L P

    2017-01-04

    Cardiovascular development is influenced by the flow-induced stress environment originating from cardiac biomechanics. To characterize the stress environment, it is necessary to quantify flow and pressure. Here, we quantify the flow field in a developing zebrafish heart during the looping stage through micro-particle imaging velocimetry and by analyzing spatiotemporal plots. We further build upon previous methods to noninvasively quantify the pressure field at a low Reynolds number using flow field data for the first time, while also comparing the impact of viscosity models. Through this method, we show that the atrium builds up pressure to ~0.25mmHg relative to the ventricle during atrial systole and that atrial expansion creates a pressure difference of ~0.15mmHg across the atrium, resulting in efficient cardiac pumping. With these techniques, it is possible to noninvasively fully characterize hemodynamics during heart development.

  7. Assessment of cardiac function in mice lacking the mitochondrial calcium uniporter.

    Science.gov (United States)

    Holmström, Kira M; Pan, Xin; Liu, Julia C; Menazza, Sara; Liu, Jie; Nguyen, Tiffany T; Pan, Haihui; Parks, Randi J; Anderson, Stasia; Noguchi, Audrey; Springer, Danielle; Murphy, Elizabeth; Finkel, Toren

    2015-08-01

    Mitochondrial calcium is thought to play an important role in the regulation of cardiac bioenergetics and function. The entry of calcium into the mitochondrial matrix requires that the divalent cation pass through the inner mitochondrial membrane via a specialized pore known as the mitochondrial calcium uniporter (MCU). Here, we use mice deficient of MCU expression to rigorously assess the role of mitochondrial calcium in cardiac function. Mitochondria isolated from MCU(-/-) mice have reduced matrix calcium levels, impaired calcium uptake and a defect in calcium-stimulated respiration. Nonetheless, we find that the absence of MCU expression does not affect basal cardiac function at either 12 or 20months of age. Moreover, the physiological response of MCU(-/-) mice to isoproterenol challenge or transverse aortic constriction appears similar to control mice. Thus, while mitochondria derived from MCU(-/-) mice have markedly impaired mitochondrial calcium handling, the hearts of these animals surprisingly appear to function relatively normally under basal conditions and during stress.

  8. Transesophageal echocardiography evaluation of the coronary blood flow and cardiac function in laparoscopic surgery and their correlation with operative wound

    Institute of Scientific and Technical Information of China (English)

    Xin-Sheng Chen

    2016-01-01

    Objective:To analyze the transesophageal echocardiography evaluation of the coronary blood flow and cardiac function in laparoscopic surgery and their correlation with operative wound.Methods:A total of 80 patients undergoing laparoscopic surgery in our hospital were randomly divided into standard pneumoperitoneum pressure group (12-15 mmHg) and high pneumoperitoneum pressure group (>15 mmHg) (n=40), and the differences in the levels of coronary blood flow and cardiac function parameters under transesophageal echocardiography as well as the content of stress hormones and acute phase proteins in serum were compared between two groups of patients.Results: Coronary blood flow parameters D, Q, PDV, MDV and DAR levels of standard pneumoperitoneum pressure group were significantly higher than those of high pneumoperitoneum pressure group; cardiac function parameters COLVOT, LVEF and LVFAC levels were significantly higher than those of high pneumoperitoneum pressure group; stress hormones Cor, Ang-Ⅰ, Ang-Ⅱ, NE, Glucagon and C-peptide as well as acute phase proteins CRP, YKL-40 and HMGB1 content in serum were significantly lower than those of high pneumoperitoneum pressure group while the acute phase protein PA content was significantly higher than that of high pneumoperitoneum pressure group.Conclusions:Transesophageal echocardiography can timely detect the excessive pneumoperitoneum damage in laparoscopic surgery to the coronary blood flow and cardiac function in patients, and also prevent the occurrence of excessive operative wound.

  9. Assessment of factors that influence weaning from long-term mechanical ventilation after cardiac surgery

    Directory of Open Access Journals (Sweden)

    Emília Nozawa

    2003-03-01

    Full Text Available OBJECTIVE: To analyze parameters of respiratory system mechanics and oxygenation and cardiovascular alterations involved in weaning tracheostomized patients from long-term mechanical ventilation after cardiac surgery. METHODS: We studied 45 patients in their postoperative period of cardiac surgery, who required long-term mechanical ventilation for more than 10 days and had to undergo tracheostomy due to unsuccessful weaning from mechanical ventilation. The parameters of respiratory system mechanics, oxigenation and the following factors were analyzed: type of surgical procedure, presence of cardiac dysfunction, time of extracorporeal circulation, and presence of neurologic lesions. RESULTS: Of the 45 patients studied, successful weaning from mechanical ventilation was achieved in 22 patients, while the procedure was unsuccessful in 23 patients. No statistically significant difference was observed between the groups in regard to static pulmonary compliance (p=0.23, airway resistance (p=0.21, and the dead space/tidal volume ratio (p=0.54. No difference was also observed in regard to the variables PaO2/FiO2 ratio (p=0.86, rapid and superficial respiration index (p=0.48, and carbon dioxide arterial pressure (p=0.86. Cardiac dysfunction and time of extracorporeal circulation showed a significant difference. CONCLUSION: Data on respiratory system mechanics and oxygenation were not parameters for assessing the success or failure. Cardiac dysfunction and time of cardiopulmonary bypass, however, significantly interfered with the success in weaning patients from mechanical ventilation.

  10. Using high resolution cardiac CT data to model and visualize patient-specific interactions between trabeculae and blood flow.

    Science.gov (United States)

    Kulp, Scott; Gao, Mingchen; Zhang, Shaoting; Qian, Zhen; Voros, Szilard; Metaxas, Dimitris; Axel, Leon

    2011-01-01

    In this paper, we present a method to simulate and visualize blood flow through the human heart, using the reconstructed 4D motion of the endocardial surface of the left ventricle as boundary conditions. The reconstruction captures the motion of the full 3D surfaces of the complex features, such as the papillary muscles and the ventricular trabeculae. We use visualizations of the flow field to view the interactions between the blood and the trabeculae in far more detail than has been achieved previously, which promises to give a better understanding of cardiac flow. Finally, we use our simulation results to compare the blood flow within one healthy heart and two diseased hearts.

  11. Hemodynamic and regional blood flow distribution responses to dextran, hydralazine, isoproterenol and amrinone during experimental cardiac tamponade

    Energy Technology Data Exchange (ETDEWEB)

    Millard, R.W.; Fowler, N.O.; Gabel, M.

    1983-06-01

    Four different interventions were examined in dogs with cardiac tamponade. Infusion of 216 to 288 ml saline solution into the pericardium reduced cardiac output from 3.5 +/- 0.3 to 1.7 +/- 0.2 liters/min as systemic vascular resistance increased from 4,110 +/- 281 to 6,370 +/- 424 dynes . s . cm-5. Left ventricular epicardial and endocardial blood flows were 178 +/- 13 and 220 +/- 12 ml/min per 100 g, respectively, and decreased to 72 +/- 14 and 78 +/- 11 ml/min per 100 g with tamponade. Reductions of 25 to 65% occurred in visceral and brain blood flows and in a composite brain sample. Cardiac output during tamponade was significantly increased by isoproterenol, 0.5 microgram/kg per min intravenously; hydralazine, 40 mg intravenously; dextran infusion or combined hydralazine and dextran, but not by amrinone. Total systemic vascular resistance was reduced by all interventions. Left ventricular epicardial flow was increased by isoproterenol, hydralazine and the hydralazine-dextran combination. Endocardial flow was increased by amrinone and the combination of hydralazine and dextran. Right ventricular myocardial blood flow increased with all interventions except dextran. Kidney cortical and composite brain blood flows were increased by both dextran alone and by the hydralazine-dextran combinations. Blood flow to small intestine was increased by all interventions as was that to large intestine by all except amrinone and hydralazine. Liver blood flow response was variable. The most pronounced hemodynamic and tissue perfusion improvements during cardiac tamponade were effected by combined vasodilation-blood volume expansion with a hydralazine-dextran combination. Isoproterenol had as dramatic an effect but it was short-lived. Amrinone was the least effective intervention.

  12. Assessment and prediction of debris-flow hazards

    Science.gov (United States)

    Wieczorek, Gerald F.; ,

    1993-01-01

    Study of debris-flow geomorphology and initiation mechanism has led to better understanding of debris-flow processes. This paper reviews how this understanding is used in current techniques for assessment and prediction of debris-flow hazards.

  13. Estimation of cardiac output and peripheral resistance using square-wave-approximated aortic flow signal

    Directory of Open Access Journals (Sweden)

    Nima eFazeli

    2012-07-01

    Full Text Available This paper presents a model-based approach to estimation of cardiac output (CO and total peripheral resistance (TPR. In the proposed approach, the response of cardiovascular system (CVS, described by the windkessel model, is tuned to the measurements of systolic, diastolic and mean arterial blood pressures (BP so as to yield optimal individual- and time-specific system time constant that is used to estimate CO and TPR. Unique aspects of the proposed approach are that it approximates the aortic flow as a train of square waves, and that it also assumes pressure-dependent arterial compliance, as opposed to the traditional windkessel model in which aortic flow is approximated as a train of impulses and constant arterial compliance is assumed. It was shown that the proposed model encompasses the standard windkessel model as a limiting case, and that it also yields more realistic BP waveform response than the standard windkessel model. The proposed approach has potential to outperform its standard counterpart by treating systolic, diastolic and mean BP as independent features in estimating CO and TPR, rather than solely resorting to pulse pressure as in the case of the standard windkessel model. Experimental results from in-vivo data collected from a number of animal subjects supports the viability of the proposed approach in that it could achieve approximately 29% and 24% reduction in CO and TPR errors when compared with its standard counterpart.

  14. Cardiac Risk Assessment, Morbidity Prediction, and Outcome in the Vascular Intensive Care Unit.

    LENUS (Irish Health Repository)

    Dover, Mary

    2013-09-17

    Objectives: The aim of this study is to examine the predictive value of the Lee revised cardiac risk index (RCRI) for a standard vascular intensive care unit (ICU) population as well as assessing the utility of transthoracic echocardiography and the impact of prior coronary artery disease (CAD) and coronary revascularization on patient outcome. Design: This is a retrospective review of prospectively maintained Vascubase and prospectively collected ICU data. Materials and Methods: Data from 363 consecutive vascular ICU admissions were collected. Findings were used to calculate the RCRI, which was then correlated with patient outcomes. All patients were on optimal medical therapy (OMT) in the form of cardioselective β-blocker, aspirin, statin, and folic acid. Results: There was no relationship found between a reduced ejection fraction and patient outcome. Mortality was significantly increased for patients with left ventricular hypertrophy (LVH) as identified on echo (14.9% vs 6.5%, P = .028). The overall complication rates were significantly elevated for patients with valvular dysfunction. Discrimination for the RCRI on receiver-operating characteristic analysis was poor, with an area under the receiver-operating characteristic curve of .621. Model calibration was reasonable with an Hosmer-Lemeshow Ĉ statistic of 2.726 (P = .256). Of those with known CAD, 41.22% of the patients receiving best medical treatment developed acute myocardial infarction (AMI) compared to 35.3% of those who previously underwent percutaneous cardiac intervention and 23.5% of those who had undergone coronary artery bypass grafting. There was 3-fold increase in major adverse clinical events in patients with troponin rise and LVH. Conclusions: The RCRI\\'s discriminatory capacity is low, and this raises difficulties in assessing cardiac risk in patients undergoing vascular intervention. The AMI is highest in the OMT group without prior cardiac intervention, which mandates protocols to

  15. The PhysioFlow thoracic impedancemeter is not valid for the measurements of cardiac hemodynamic parameters in chronic anemic patients.

    Directory of Open Access Journals (Sweden)

    Pascal Bogui

    Full Text Available The aim of the present study was to test the validity of the transthoracic electrical bioimpedance method PhysioFlow® to measure stroke volume in patients with chronic anemia. Stroke volume index (SVI, as well as cardiac index (CI obtained by transthoracic electrical bioimpedance method and doppler echocardiography were compared in healthy subjects (n = 25 and patients with chronic anemia (i.e. mainly with sickle cell anemia; n = 32, at rest. While doppler echocardiography was able to detect difference in SVI between the two populations, the Physioflow® failed to detect any difference. Bland & Altman analyses have demonstrated no interchangeability between the two methods to assess CI and SVI in anemic patients and healthy subjects. While doppler echocardiography displayed a good concordance for SVI results with those obtained in the literature for anemic patients, the Physioflow® did not. Finally, in contrast to doppler echocardiography: 1 the CI obtained with the Physioflow® was not correlated with the hemoglobin level and 2 the stroke volume determined by the Physioflow® was highly influenced by body surface area. In conclusion, our findings indicate that the Physioflow® device is inaccurate for the measurement of SVI and CI in patients with chronic anemia and has a poor accuracy for the measurement of these parameters in African healthy subjects.

  16. Early Diagnosis of Penetrating Cardiac and Pleural Injury by Extended Focused Assessment with Sonography for Trauma

    Science.gov (United States)

    Singaravelu, K. P.; Saya, Rama Prakasha; Pandit, Vinay R.

    2016-01-01

    In India, stab injury is not uncommon, but identifying potential life threatening conditions in the emergency room (ER) and initiating prompt treatment are challenging. This is a case report of a young patient who presented to the ER with assault injury to the chest and shock; timely extended focused assessment with sonography for trauma helped to fast-track the patient to the operating room. A brief review of diagnosis and management of penetrating cardiac injury is presented herewith.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  18. Magnetic resonance imaging assessment of cardiac dysfunction in δ-sarcoglycan null mice.

    Science.gov (United States)

    Wansapura, Janaka P; Millay, Douglas P; Dunn, R Scott; Molkentin, Jeffery D; Benson, D Woodrow

    2011-01-01

    Delta-sarcoglycan (δ-sarcoglycan) null, Scgd(-/-), mice develop cardiac and skeletal muscle histopathological alterations similar to those in humans with limb-girdle muscular dystrophy. The objective of this study was to assess the feasibility of using MRI to investigate cardiac dysfunction in Scgd(-/-) mice. Cardiac MRI of 8 month old Scgd(-/-) and wild type (WT) mice was performed. Compared to WT, Scgd(-/-) mice had significantly lower LV ejection fraction (44±5% vs. 66±4%, p=0.014), lower RV ejection fraction (25±2% vs. 51±3%, p<0.001) lower myocardial circumferential strain, (15.0±0.3% vs. 16.9±0.3%, p=0.007) and RV dilatation (54±3 μL vs. 40±3 μL, p=0.007). The regional circumferential strain also demonstrated significant temporal dyssynchrony between opposing regions of the Scgd(-/-) LV. Our results demonstrate severe cardiac dysfunction in Scgd(-/-) mice at 8 months. The study identifies a set of non-invasive markers that could be used to study efficacy of novel therapeutic agents in dystrophic mice.

  19. Open-loop (feed-forward) and feedback control of coronary blood flow during exercise, cardiac pacing, and pressure changes.

    Science.gov (United States)

    Pradhan, Ranjan K; Feigl, Eric O; Gorman, Mark W; Brengelmann, George L; Beard, Daniel A

    2016-06-01

    A control system model was developed to analyze data on in vivo coronary blood flow regulation and to probe how different mechanisms work together to control coronary flow from rest to exercise, and under a variety of experimental conditions, including cardiac pacing and with changes in coronary arterial pressure (autoregulation). In the model coronary flow is determined by the combined action of a feedback pathway signal that is determined by the level of plasma ATP in coronary venous blood, an adrenergic open-loop (feed-forward) signal that increases with exercise, and a contribution of pressure-mediated myogenic control. The model was identified based on data from exercise experiments where myocardial oxygen extraction, coronary flow, cardiac interstitial norepinephrine concentration, and arterial and coronary venous plasma ATP concentrations were measured during control and during adrenergic and purinergic receptor blockade conditions. The identified model was used to quantify the relative contributions of open-loop and feedback pathways and to illustrate the degree of redundancy in the control of coronary flow. The results indicate that the adrenergic open-loop control component is responsible for most of the increase in coronary blood flow that occurs during high levels of exercise. However, the adenine nucleotide-mediated metabolic feedback control component is essential. The model was evaluated by predicting coronary flow in cardiac pacing and autoregulation experiments with reasonable fits to the data. The analysis shows that a model in which coronary venous plasma adenine nucleotides are a signal in local metabolic feedback control of coronary flow is consistent with the available data.

  20. Dynamic proliferation assessment in flow cytometry.

    Science.gov (United States)

    Diermeier-Daucher, Simone; Brockhoff, Gero

    2010-09-01

    Dynamic proliferation assessment via flow cytometry is legitimately supposed to be the most powerful tool for recording cell cycle kinetics in-vitro. The preeminent feature is a single cell-based multi-informative analysis by temporal high-resolution. Flow cytometric approaches are based on labeling of proliferating cells via thymidine substitution by a base analog (e.g., 5-bromo-2'-deoxyuridine, BrdU) that is added to cell cultures either for a short period of time (pulse labeling) or continuously until cell harvesting. This unit describes the alternative use of the thymidine analog 5-ethynyl-2'-deoxyuridine (EdU) in place of BrdU for three different applications: (1) dynamic proliferation assessment by EdU pulse cell labeling; (2) the same approach as (1) but in combination with live/dead cell discrimination; and (3) dynamic cell cycle analysis based on continuous cell labeling with EdU and Hoechst fluorochrome quenching. In contrast to the detection of BrdU incorporation, EdU-positive cells can be identified by taking advantage of click chemistry, which facilitates a simplified and fast cell preparation. Further analysis options but also limitations of the utilization of EdU are discussed.

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

    Science.gov (United States)

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

    2008-09-01

    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.

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

    Science.gov (United States)

    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...

  3. Cardiac pathologies in female carriers of Duchenne muscular dystrophy assessed by cardiovascular magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Schelhorn, Juliane; Schemuth, Haemi; Nensa, Felix; Nassenstein, Kai; Forsting, Michael; Schlosser, Thomas [University Hospital Essen, Department of Diagnostic and Interventional Radiology and Neuroradiology, Essen (Germany); Schoenecker, Anne; Neudorf, Ulrich [University Hospital Essen, Department of Pediatric Cardiology, Essen (Germany); Schara, Ulrike [University Hospital Essen, Department of Pediatric Neurology, Essen (Germany)

    2015-10-15

    Duchenne muscular dystrophy (DMD) is the most common and severe dystrophinopathy. DMD carriers rarely present with clinical symptoms, but may suffer from cardiac involvement. Because echocardiographic findings are inconsistent and cardiac magnetic resonance imaging (CMRI) data are limited, this study sought to investigate asymptomatic carriers for cardiac abnormalities using CMRI. Fifteen genetically confirmed DMD carriers (age, 32.3 ± 10.2 years) were prospectively examined on a 1.5T MR system. Cine, T2, and late-gadolinium-enhanced (LGE) images were acquired, and were evaluated in consensus by two experienced readers. Left ventricular (LV) parameters were analysed semiautomatically, normalized to BSA. Normalized LV end-diastolic volume was increased in 7 % (73.7 ± 16.8 ml/m{sup 2}; range, 48-116 ml/m{sup 2}) and normalized LV end-systolic volume in 20 % (31.5 ± 13.3 ml/m{sup 2}; range, 15-74 ml/m{sup 2}). EF was reduced in 33 % (58.4 ± 7.6 %; range, 37-69 %) and normalized LV myocardial mass in 80 % (40.5 ± 6.8 g/m{sup 2}; range, 31-55 g/m{sup 2}). In 80 %, regional myocardial thinning was detected in more than one segment. In 13 % and 40 %, apical-lateral accentuation of LV non-compaction was present. LGE was found in 60 % (midmyocardial inferolateral accentuation). Given the high frequency of cardiac pathologies detected by CMRI, regular cardiac risk assessment is advisable for DMD carriers. Besides clinical examination, CMRI is an excellent tool for this purpose. (orig.)

  4. Vector flow mapping for assessing Beagle dogs′ left ventricular vortex in selective bi-polar single site cardiac pacing%超声血流向量成像评价健康比格犬心脏不同位点起搏左心室血流涡旋

    Institute of Scientific and Technical Information of China (English)

    丁戈琦; 尹立雪; 王志刚; 陆景; 李文华; 张红梅

    2015-01-01

    Objective To investigate the changes of left ventricular(LV) vortex strength(VS) and distribution during selective cardiac pacing in a phases of cardiac cycle using vector flow mapping techniques ,and associate with LV mechanical performance ,so as to provide basic experimental database for optimizing the sites of the artificial cardiac pacing in clinic conditions .Methods Eight heathy open‐chest Beagle dog models were employed for selective right ventricular apical (RVAP ) ,left ventricular apical (LVAP) and lateral wall pacing (LVLP) .The standard two‐dimensional apical three views with color Doppler flow and dynamic two‐dimensional images were acquired consecutively in three cardiac cycles for further off‐line analysis ,conventional parameters were measured at same time .Results Compared with baseline ,LVSV ,LVEF ,LVCO and dp/dtmax were both reduced ,and the parameters obtained leftside cardiac pacing were lower than that of right ventricular pacing ( P < 0 0.5) ,there′s no significant difference in E/Vp .The vortex pattern ,distribution and vorticity at six typical phases induced by selective cardiac pacing were totally different from those at baseline with sinus rhythm ,and leftside pacing were worsen than RVAP ,the LVAP were most obvious .On multivariable regression analysis ,the VS during ES (VSES ) at baseline was independently related to late‐diastolic VS and longitudinal strain (R2 = 0 6.3 ,P < 0 0.01 and P=0 0.03 ,respectively) .Conclusions The selective cardiac pacing could induce intracardiac vortex changes and differ from that at baseline ,and the persistence of vortex from late diastole into ES is a haemodynamic measure of coupling between diastole and systole .%目的:应用超声血流向量成像(VFM)技术评价健康比格犬心脏不同位点起搏心动周期内左室流场涡旋分布、强度变化及心肌力学参数,探讨起搏状态下心腔内涡旋变化特征,为临床优化人工心脏起搏位点提供流体

  5. Chronic impairment of leg muscle blood flow following cardiac catheterization in childhood. [/sup 133/Xe clearance measurements

    Energy Technology Data Exchange (ETDEWEB)

    Skovranek, J.; Samanek, M.

    1979-01-01

    In 99 patients with congenital heart defects or chronic respiratory disease without clinical symptoms of disturbances in peripheral circulation, resting and maximal blood flow in the anterior tibial muscle of both extremities were investigated 2.7 yrs (average) after cardiac catheterization. The method used involved /sup 133/Xe clearance. Resting blood flow was normal and no difference could be demonstrated between the extremity originally used for catheterization and the contralateral control extremity. No disturbance in maximal blood flow could be proved in the extremity used for catheterization by the venous route only. Maximal blood flow was significantly lower in that extremity where the femoral artery had been catheterized or cannulated for pressure measurement and blood sampling. The disturbance in maximal flow was shown regardless of whether the arterial catheterization involved the Seldinger percutaneous technique, arteriotomy, or mere cannulation of the femoral artery. The values in the involved extremity did not differ significantly from the values in a healthy population.

  6. Standardized echocardiographic assessment of cardiac function in normal adult zebrafish and heart disease models

    Science.gov (United States)

    Wang, Louis W.; Huttner, Inken G.; Santiago, Celine F.; Kesteven, Scott H.; Yu, Ze-Yan; Feneley, Michael P.

    2017-01-01

    ABSTRACT The zebrafish (Danio rerio) is an increasingly popular model organism in cardiovascular research. Major insights into cardiac developmental processes have been gained by studies of embryonic zebrafish. However, the utility of zebrafish for modeling adult-onset heart disease has been limited by a lack of robust methods for in vivo evaluation of cardiac function. We established a physiological protocol for underwater zebrafish echocardiography using high frequency ultrasound, and evaluated its reliability in detecting altered cardiac function in two disease models. Serial assessment of cardiac function was performed in wild-type zebrafish aged 3 to 12 months and the effects of anesthetic agents, age, sex and background strain were evaluated. There was a varying extent of bradycardia and ventricular contractile impairment with different anesthetic drugs and doses, with tricaine 0.75 mmol l−1 having a relatively more favorable profile. When compared with males, female fish were larger and had more measurement variability. Although age-related increments in ventricular chamber size were greater in females than males, there were no sex differences when data were normalized to body size. Systolic ventricular function was similar in both sexes at all time points, but differences in diastolic function were evident from 6 months onwards. Wild-type fish of both sexes showed a reliance on atrial contraction for ventricular diastolic filling. Echocardiographic evaluation of adult zebrafish with diphtheria toxin-induced myocarditis or anemia-induced volume overload accurately identified ventricular dilation and altered contraction, with suites of B-mode, ventricular strain, pulsed-wave Doppler and tissue Doppler indices showing concordant changes indicative of myocardial hypocontractility or hypercontractility, respectively. Repeatability, intra-observer and inter-observer correlations for echocardiographic measurements were high. We demonstrate that high

  7. Pain after Cardiac Surgery: A Review of the Assessment and Management

    Directory of Open Access Journals (Sweden)

    Parizad Razieh

    2014-10-01

    Full Text Available Objective: Surgery is among the causes of acute pain. One of the major problems of patients after surgical procedures is postoperative pain. Annually, millions of people throughout the world undergo surgery and experience different intensities of postoperative pain. Due to physiological changes and given the stability of the heart and lung, the management and control of pain is rarely considered as a priority in the care of patients after cardiac surgery. Cardiac surgical patients experience pain due to the surgical incision and between the ribs nerve injury created during the course of the surgery, and irritation and inflammation of the pleura by catheters. Control and management of pain in intensive care units (ICU are the main tasks in nursing care. The purpose of this review study was the investigation, assessment, and management of pain in patients after cardiac surgery. Materials and Methods: In this study, the literature available on Magiran, Google Scholar, ScienceDirect, and PubMed were collected, and after reviewing, the relevant literature was studied. Results: Although pain is one of the major stressors in patients undergoing surgery, the measures taken for the treatment and care of these patients are associated with experiencing pain. In this regard, all the resources have emphasized the using of guidelines and tools to assess patients' pain. However, in cardiac surgery patients, sufficient attention is not paid to pain control. Patients reported poorly controlled pain and experiences of moderate to severe pain after surgery. Conclusion: Pain is a subjective experience, and in patients who cannot report their pain, it should be considered important. According to numerous studies, pain control is not performed in ICUs. Thus, efforts should be made for appropriate control and reduction of pain, use of valid methods to determine and control pain, and improvement of the quality of the programs.

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

    Science.gov (United States)

    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.

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

    Institute of Scientific and Technical Information of China (English)

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

    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 ofventricular 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 retumed 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

  10. Applications of pulsed Doppler flow mapping to left sided cardiac valvular lesions.

    Science.gov (United States)

    Kalmanson, D; Veyrat, C; Gourtchiglouian, C; Bas, S; Abitbol, G

    The flow mapping procedure has been developed in parallel to the standard pulsed Doppler procedure. It has a different purpose--picking up flow signals at the site of lesions rather than calibrating velocities--and has its own methodology, developed within the last six years. On the basis of invasive correlations performed in 267 cases of valvular heart disease, we review the three-fold purpose of the flow mapping technique: diagnosing lesions, relying on the presence of flow anomalies; assessing their severity, relying on the spatial spreading of these flow signals; and identifying the site of the lesion, which is a specific advantage, relying on the anatomical location of these flow signals and/or on the direction of the jets. For example, using this technique, it is now possible to easily differentiate a cusp tear from a leak of a bioprosthesis, to measure the size of the leaks, and to reconstruct the image of aortic or mitral stenotic areas. These optimal results are only obtained using an appropriate methodology which mainly includes a) the selection of adequate two-dimensional short axis planes in order to explore the diseased valve in its entirety, because of frequent assymetrical orifices, and to pick up the jets at their starting point, b) measurements of the abnormal areas, c) when jets are studied, a three dimensional approach is required in order to cope with the three dimensional nature of the jet and to make available the calculation of three dimensional indices of severity.(ABSTRACT TRUNCATED AT 250 WORDS)

  11. Deformation analysis of 3D tagged cardiac images using an optical flow method

    Directory of Open Access Journals (Sweden)

    Gorman Robert C

    2010-03-01

    Full Text Available Abstract Background This study proposes and validates a method of measuring 3D strain in myocardium using a 3D Cardiovascular Magnetic Resonance (CMR tissue-tagging sequence and a 3D optical flow method (OFM. Methods Initially, a 3D tag MR sequence was developed and the parameters of the sequence and 3D OFM were optimized using phantom images with simulated deformation. This method then was validated in-vivo and utilized to quantify normal sheep left ventricular functions. Results Optimizing imaging and OFM parameters in the phantom study produced sub-pixel root-mean square error (RMS between the estimated and known displacements in the x (RMSx = 0.62 pixels (0.43 mm, y (RMSy = 0.64 pixels (0.45 mm and z (RMSz = 0.68 pixels (1 mm direction, respectively. In-vivo validation demonstrated excellent correlation between the displacement measured by manually tracking tag intersections and that generated by 3D OFM (R ≥ 0.98. Technique performance was maintained even with 20% Gaussian noise added to the phantom images. Furthermore, 3D tracking of 3D cardiac motions resulted in a 51% decrease in in-plane tracking error as compared to 2D tracking. The in-vivo function studies showed that maximum wall thickening was greatest in the lateral wall, and increased from both apex and base towards the mid-ventricular region. Regional deformation patterns are in agreement with previous studies on LV function. Conclusion A novel method was developed to measure 3D LV wall deformation rapidly with high in-plane and through-plane resolution from one 3D cine acquisition.

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

    Directory of Open Access Journals (Sweden)

    Heather Tulloch

    2014-12-01

    Full Text Available 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.

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

    Science.gov (United States)

    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.

  14. Quantitative assessment of myocardial blush grade in patients with coronary artery disease and in cardiac transplant recipients

    Institute of Scientific and Technical Information of China (English)

    Nina; Patricia; Hofmann; Hartmut; Dickhaus; Hugo; A; Katus; Grigorios; Korosoglou

    2014-01-01

    Quantitative assessment of myocardial perfusion by myocardial blush grade(MBG) is an angiographic computer-assisted method to assess myocardial tissue-level reperfusion in patients with acute coronary syndromes and microvascular integrity in heart transplant recipients with suspected cardiac allograft vasculopathy. This review describes the ability of quantitative MBG as a simple, fast and cost effective modality for the prompt diagnosis of impaired microvascular integrity during routine cardiac catheterization. Herein, we summarize the existing evidence, its usefulness in the clinical routine, and compare this method to other techniques which can be used for the assessment of myocardial perfusion.

  15. Radiographic assessment of the cardiac silhouette in clinically normal large- and small-breed dogs.

    Science.gov (United States)

    Mostafa, Ayman A; Berry, Clifford R

    2017-02-01

    OBJECTIVE To determine manubrium heart scores (MHSs) from measurements of cardiac short-axis length (cSAL) and long-axis length (cLAL) relative to the corresponding manubrium length (ML) on thoracic radiographic views of dogs and assess correlation of MHSs with vertebral heart scores (VHSs). ANIMALS 120 clinically normal large-breed dogs (LBDs) and small-breed dogs (SBDs). PROCEDURES On right lateral views (RLVs) and ventrodorsal views (VDVs) for each dog, cSAL and cLAL were measured and expressed as a ratio; the cSAL:ML ratio (short-MHS), cLAL:ML ratio (long-MHS), and cSAL-and-cLAL:ML ratio (overall-MHS) were also calculated. The VHS was determined from the RLV. Correlation of VHS with MHS was assessed. RESULTS On RLVs and VDVs, mean cSAL:cLAL ratios were 0.77 (SD, 0.05) and 0.72 (SD, 0.05), respectively, in 60 LBDs and 0.81 (SD, 0.06) and 0.78 (SD, 0.06), respectively, in 60 SBDs. In LBDs, mean short-MHS, long-MHS, and overall-MHS were 2.1 (SD, 0.22), 2.7 (SD, 0.24), and 4.8 (SD, 0.5), respectively, on RLVs and 2.3 (SD, 0.26), 3.2 (SD, 0.34), and 5.4 (SD, 0.6), respectively, on VDVs. In SBDs, mean short-MHS, long-MHS, and overall-MHS were 2.4 (SD, 0.39), 2.9 (SD, 0.50), and 5.3 (SD, 0.83), respectively, on RLVs and 2.5 (SD, 0.44), 3.2 (SD, 0.51), and 5.8 (SD, 0.92), respectively, on VDVs. Mean VHSs were 10.73 (SD, 0.52) and 10.27 (SD, 0.81) in LBDs and SBDs, respectively. A significant correlation was identified between VHS and each MHS in LBDs. CONCLUSIONS AND CLINICAL RELEVANCE In the dogs evaluated, radiographic cardiac dimensions and MHSs were correlated. Validity of the MHS for cardiac dimension assessment in other healthy dogs and dogs with cardiac disease warrants investigation.

  16. Noninvasive cardiac assessment in children of women with systemic lupus erythematosus

    Directory of Open Access Journals (Sweden)

    Maria de Fátima Monteitro Pereira Leite

    2003-11-01

    Full Text Available OBJECTIVE: Noninvasive cardiac assessment of newborns and infants of women with systemic lupus erythematosus. The children had no congenital total atrioventricular block and were compared with the children of healthy women. METHODS: We prospectively assessed 13 newborns and infants aged 1 to 60 days, children of women with systemic lupus erythematosus and without congenital total atrioventricular block. These children were compared with 30 children of women who had no lupus or anti-Ro/SSA antibodies, and no risk factors for congenital heart disease either. Their age groups matched. The following examinations were performed: cardiological physical examination, electrocardiography, echocardiography, and signal-averaged electrocardiography. RESULTS: The statistical analysis showed no significant difference in ventricular function or in the cardiac conduction system between the groups. CONCLUSION: In regard to the conduction system and ventricular function in the absence of total atrioventricular block, no statistically significant difference was observed between the children of women with systemic lupus erythematosus and children of healthy women.

  17. Debris flow hazards mitigation--Mechanics, prediction, and assessment

    Science.gov (United States)

    Chen, C.-L.; Major, J.J.

    2007-01-01

    These proceedings contain papers presented at the Fourth International Conference on Debris-Flow Hazards Mitigation: Mechanics, Prediction, and Assessment held in Chengdu, China, September 10-13, 2007. The papers cover a wide range of topics on debris-flow science and engineering, including the factors triggering debris flows, geomorphic effects, mechanics of debris flows (e.g., rheology, fluvial mechanisms, erosion and deposition processes), numerical modeling, various debris-flow experiments, landslide-induced debris flows, assessment of debris-flow hazards and risk, field observations and measurements, monitoring and alert systems, structural and non-structural countermeasures against debris-flow hazards and case studies. The papers reflect the latest devel-opments and advances in debris-flow research. Several studies discuss the development and appli-cation of Geographic Information System (GIS) and Remote Sensing (RS) technologies in debris-flow hazard/risk assessment. Timely topics presented in a few papers also include the development of new or innovative techniques for debris-flow monitoring and alert systems, especially an infra-sound acoustic sensor for detecting debris flows. Many case studies illustrate a wide variety of debris-flow hazards and related phenomena as well as their hazardous effects on human activities and settlements.

  18. TU-A-12A-09: Absolute Blood Flow Measurement in a Cardiac Phantom Using Low Dose CT

    Energy Technology Data Exchange (ETDEWEB)

    Ziemer, B; Hubbard, L; Lipinski, J; Molloi, S [University of California, Irvine, CA (United States)

    2014-06-15

    Purpose: To investigate a first pass analysis technique to measure absolute flow from low dose CT images in a cardiac phantom. This technique can be combined with a myocardial mass assignment to yield absolute perfusion using only two volume scans and reduce the radiation dose to the patient. Methods: A four-chamber cardiac phantom and perfusion chamber were constructed from poly-acrylic and connected with tubing to approximate anatomical features. The system was connected to a pulsatile pump, input/output reservoirs and power contrast injector. Flow was varied in the range of 1-2.67 mL/s with the pump operating at 60 beats/min. The system was imaged once a second for 14 seconds with a 320-row scanner (Toshiba Medical Systems) using a contrast-enhanced, prospective-gated cardiac perfusion protocol. Flow was calculated by the following steps: subsequent images of the perfusion volume were subtracted to find the contrast entering the volume; this was normalized by an upstream, known volume region to convert Hounsfield (HU) values to concentration; this was divided by the subtracted images time difference. The technique requires a relatively stable input contrast concentration and no contrast can leave the perfusion volume before the flow measurement is completed. Results: The flow calculated from the images showed an excellent correlation with the known rates. The data was fit to a linear function with slope 1.03, intercept 0.02 and an R{sup 2} value of 0.99. The average root mean square (RMS) error was 0.15 mL/s and the average standard deviation was 0.14 mL/s. The flow rate was stable within 7.7% across the full scan and served to validate model assumptions. Conclusion: Accurate, absolute flow rates were measured from CT images using a conservation of mass model. Measurements can be made using two volume scans which can substantially reduce the radiation dose compared with current dynamic perfusion techniques.

  19. Cerebral oximetry and cerebral blood flow monitoring in 2 pediatric survivors with out-of-hospital cardiac arrest.

    Science.gov (United States)

    Abramo, Thomas; Aggarwal, Nitin; Kane, Ian; Crossman, Kristen; Meredith, Mark

    2014-04-01

    In pediatric out-of-hospital cardiac arrest (POHCA), cardiovascular monitoring tools have improved resuscitative endeavors and cardiovascular outcomes but with still poor neurologic outcomes. Regarding cardiac arrest in patients with congenital heart disease during surgery, the application of cerebral oximetry with blood volume index (BVI) during the resuscitation has shown significant results and prognostic significance. We present 2 POHCA patients who had cerebral oximetry with BVI monitoring during their arrest and postarrest phase in the emergency department and its potential prognostic aspect.Basic procedures include left and right cerebral oximetry with BVI monitoring at every 5-second interval during cardiac arrest, resuscitation, and postarrest in 2 POHCA patients in the pediatric emergency department.Regional cerebral tissue oxygen saturation (rSo2) with BVI readings in these 2 POHCA survivors demonstrated interesting cerebral physiology, blood flow, and potential prognostic outcome. In 1 patient, the reference range of cerebral rSo2 with positive blood flow during arrest and postarrest phases consistently occurred. This neurologic monitoring had its significance when the resuscitation effectiveness was used and end-tidal CO2 changes were lost. The other patient's cerebral rSo2 with simultaneous BVI readings and trending showed the effectiveness of the emergency medical services (EMS) resuscitation.Cerebral oximetry with cerebral blood flow index monitoring in these POHCA survivors demonstrates compelling periarrest and postarrest cerebral physiology information and prognostication. Cerebral oximetry with cerebral BVI monitoring during these arrest phases has potential as a neurologic monitor for the resuscitative intervention's effectiveness and its possible neurologic prognostic application in the pediatric OCHA patients.

  20. Improving the assessment of instream flow needs for fish populations

    Energy Technology Data Exchange (ETDEWEB)

    Sale, M.J. (Oak Ridge National Lab., TN (USA)); Otto, R.G. (Otto (R.G.) and Associates, Arlington, VA (USA))

    1991-01-01

    Instream flow requirements are one of the most frequent and most costly environmental issues that must be addressed in developing hydroelectric projects. Existing assessment methods for determining instream flow requirements have been criticized for not including all the biological response mechanisms that regulate fishery resources. A new project has been initiated to study the biological responses of fish populations to altered stream flows and to develop improved ways of managing instream flows. 21 refs., 3 figs.

  1. Cardiac remodeling following percutaneous mitral valve repair. Initial results assessed by cardiovascular magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Radunski, U.K [University Heart Center, Hamburg (Germany). Cardiology; Franzen, O. [Rigshospitalet, Copenhagen (Denmark). Cardiology; Barmeyer, A. [Klinikum Dortmund (Germany). Kardiologie; and others

    2014-10-15

    Percutaneous mitral valve repair with the MitraClip device (Abbott Vascular, Redwood City, California, USA) is a novel therapeutic option in patients with mitral regurgitation. This study evaluated the feasibility of cardiac volume measurements by cardiovascular magnetic resonance imaging (CMR) to assess reverse myocardial remodeling in patients after MitraClip implantation. 12 patients underwent CMR at baseline (BL) before and at 6 months follow-up (FU) after MitraClip implantation. Cine-CMR was performed in short- and long-axes for the assessment of left ventricular (LV), right ventricular (RV) and left atrial (LA) volumes. Assessment of endocardial contours was not compromised by the device-related artifact. No significant differences in observer variances were observed for LV, RV and LA volume measurements between BL and FU. LV end-diastolic (median 127 [IQR 96-150] vs. 112 [86-150] ml/m{sup 2}; p=0.03) and LV end-systolic (82 [54-91] vs. 69 [48-99] ml/m{sup 2}; p=0.03) volume indices decreased significantly from BL to FU. No significant differences were found for RV end-diastolic (94 [75-103] vs. 99 [77-123] ml/m{sup 2}; p=0.91), RV end-systolic (48 [42-80] vs. 51 [40-81] ml/m{sup 2}; p=0.48), and LA (87 [55-124] vs. 92 [48-137]R ml/m{sup 2}; p=0.20) volume indices between BL and FU. CMR enables the assessment of cardiac volumes in patients after MitraClip implantation. Our CMR findings indicate that percutaneous mitral valve repair results in reverse LV but not in RV or LA remodeling.

  2. 20-Hydroxyeicosatetraenoic Acid Inhibition by HET0016 Offers Neuroprotection, Decreases Edema, and Increases Cortical Cerebral Blood Flow in a Pediatric Asphyxial Cardiac Arrest Model in Rats.

    Science.gov (United States)

    Shaik, Jafar Sadik B; Poloyac, Samuel M; Kochanek, Patrick M; Alexander, Henry; Tudorascu, Dana L; Clark, Robert Sb; Manole, Mioara D

    2015-11-01

    Vasoconstrictive and vasodilatory eicosanoids generated after cardiac arrest (CA) may contribute to cerebral vasomotor disturbances and neurodegeneration. We evaluated the balance of vasodilator/vasoconstrictor eicosanoids produced by cytochrome P450 (CYP) metabolism, and determined their role on cortical perfusion, functional outcome, and neurodegeneration after pediatric asphyxial CA. Cardiac arrest of 9 and 12 minutes was induced in 16- to 18-day-old rats. At 5 and 120 minutes after CA, we quantified the concentration of CYP eicosanoids in the cortex and subcortical areas. In separate rats, we inhibited 20-hydroxyeicosatetraenoic acid (20-HETE) synthesis after CA and assessed cortical cerebral blood flow (CBF), neurologic deficit score, neurodegeneration, and edema. After 9 minutes of CA, vasodilator eicosanoids markedly increased versus sham. Conversely, after 12 minutes of CA, vasoconstrictor eicosanoid 20-HETE increased versus sham, without compensatory increases in vasodilator eicosanoids. Inhibition of 20-HETE synthesis after 12 minutes of CA decreased cortical 20-HETE levels, increased CBF, reduced neurologic deficits at 3 hours, and reduced neurodegeneration and edema at 48 hours versus vehicle-treated rats. In conclusion, cerebral vasoconstrictor eicosanoids increased after a pediatric CA of 12 minutes. Inhibition of 20-HETE synthesis improved cortical perfusion and short-term neurologic outcome. These results suggest that alterations in CYP eicosanoids have a role in cerebral hypoperfusion and neurodegeneration after CA and may represent important therapeutic targets.

  3. CMR Imaging With Rapid Visual T1 Assessment Predicts Mortality in Patients Suspected of Cardiac Amyloidosis

    Science.gov (United States)

    White, James A.; Kim, Han W.; Shah, Dipan; Fine, Nowell; Kim, Ki-Young; Wendell, David C.; Al-Jaroudi, Wael; Parker, Michele; Patel, Manesh; Gwadry-Sridhar, Femida; Judd, Robert M.; Kim, Raymond J.

    2014-01-01

    OBJECTIVES This study tested the diagnostic and prognostic utility of a rapid, visual T1 assessment method for identification of cardiac amyloidosis (CA) in a “real-life” referral population undergoing cardiac magnetic resonance for suspected CA. BACKGROUND In patients with confirmed CA, delayed-enhancement cardiac magnetic resonance (DE-CMR) frequently shows a diffuse, global hyperenhancement (HE) pattern. However, imaging is often technically challenging, and the prognostic significance of diffuse HE is unclear. METHODS Ninety consecutive patients referred for suspected CA and 64 hypertensive patients with left ventricular hypertrophy (LVH) were prospectively enrolled and underwent a modified DE-CMR protocol. After gadolinium administration a method for rapid, visual T1 assessment was used to identify the presence of diffuse HE during the scan, allowing immediate optimization of settings for the conventional DE-CMR that followed. The primary endpoint was all-cause mortality. RESULTS Among patients with suspected CA, 66% (59 of 90) demonstrated HE, with 81% (48 of 59) of these meeting pre-specified visual T1 assessment criteria for diffuse HE. Among hypertensive LVH patients, 6% (4 of 64) had HE, with none having diffuse HE. During 29 months of follow-up (interquartile range: 12 to 44 months), there were 50 (56%) deaths in patients with suspected CA and 4 (6%) in patients with hypertensive LVH. Multivariable analysis demonstrated that the presence of diffuse HE was the most important predictor of death in the group with suspected CA (hazard ratio: 5.5, 95% confidence interval: 2.7 to 11.0; p < 0.0001) and in the population as a whole (hazard ratio: 6.0, 95% confidence interval 3.0 to 12.1; p < 0.0001). Among 25 patients with myocardial histology obtained during follow-up, the sensitivity, specificity, and accuracy of diffuse HE in the diagnosis of CA were 93%, 70%, and 84%, respectively. CONCLUSIONS Among patients suspected of CA, the presence of diffuse HE by

  4. Assessment of inflammatory factors and cardiac troponin T in hemodialysis patients

    Directory of Open Access Journals (Sweden)

    Falaknazi Kianoosh

    2009-01-01

    Full Text Available Hemodialysis (HD patients suffer from chronic inflammations which make them at increased risk of cardiovascular diseases. The purpose of this study was to see if there is a significant association between inflammatory factors such as ferritin and C-reactive protein (CRP as well as troponin T in patients on HD. We assessed these serum factors as well as other known cardiac risk factors in 53 patients on HD. The serum ferritin and CRP levels were measured by chemiluminescence′s immune assay while troponin T levels were measured by electrochemist luminescence immune assay. We found that serum concentrations of CRP and ferritin were not significantly higher in patients on HD with known cardiac risk factors (compared with the control group (p< 0.05. However, the serum troponin T levels in HD patients with cardiovascular risk factors were significantly higher than the control group. Our study suggests that elevated serum troponin T levels can play an important role as a predictor of cardiovascular disease in HD patients. Also, inflammatory factors such as CRP and ferritin may be influenced by chronic inflammation or nutritional status of these patients.

  5. Echocardiographic and phonocardiographic assessment of the St. Jude cardiac valve prosthesis.

    Science.gov (United States)

    DePace, N L; Kotler, M N; Mintz, G S; Lichtenberg, R; Goel, I P; Segal, B L

    1981-09-01

    Forty-three consecutive patients with a St. Jude mitral, aortic, or combined prosthesis were studied by simultaneous phonocardiography and echocardiography. Twenty-eight patients had a mitral prosthesis, 20 an aortic prosthesis, and five had both. No opening click was recorded in any patient; however, a loud aortic or mitral closing click was recorded in all 43 patients. In patients with St. Jude mitral valve prosthesis, an echo-free space separated the two leaflets during diastole; seven of these also had a mid-diastolic closing and late diastolic reopening motion; two of the seven had an associated closing mid-diastolic click. A mid-diastolic rumble was recorded in six of 28 patients with St. Jude mitral valve prosthesis. In patients with a St. Jude aortic valve prosthesis, left atrium leaflet motion was recorded in 17 of 20 patients and was indistinguishable in appearance from echocardiograms obtained with various eccentric monocusp valves. In addition, we report one case of malfunction of a St. Jude mitral valve and one case of a paravalvular leak diagnosed by echophonocardiography. We concluded that the St. Jude cardiac prosthesis has variable normal phonocardiographic-echocardiographic patterns. Knowledge of these variable patterns is important in assessing patients with suspected malfunction of a St. Jude cardiac prosthesis.

  6. Assessing cardiac preload by the Initial Systolic Time Interval obtained from impedance cardiography

    Directory of Open Access Journals (Sweden)

    Jan H Meijer

    2010-01-01

    Full Text Available The Initial Systolic Time Interval (ISTI, obtained from the electrocardiogram (ECG and impedance cardiogram (ICG, is considered to be a measure for the time delay between the electrical and mechanical activity of the heart and reflects an early active period of the cardiac cycle. The clinical relevance of this time interval is subject of study. This paper presents preliminary results of a pilot study investigating the use of ISTI in evaluating and predicting the circulatory response to fluid administration in patients after coronary artery bypass graft surgery, by comparing ISTI with cardiac output (CO responsiveness. Also the use of the pulse transit time (PTT, earlier recommended for this purpose, is investigated. The results show an inverse relationship between ISTI and CO at all moments of fluid administration and also an inverse relationship between the changes ΔISTI and ΔCO before and after full fluid administration. No relationships between PTT and CO or ΔPTT and ΔCO were found. It is concluded that ISTI is dependent upon preload, and that ISTI has the potential to be used as a clinical parameter assessing preload.

  7. Sublingual Microcirculation is Impaired in Post-cardiac Arrest Patients

    DEFF Research Database (Denmark)

    G. Omar, Yasser; Massey, Michael; Wiuff Andersen, Lars;

    2013-01-01

    AIM: We hypothesized that microcirculatory dysfunction, similar to that seen in sepsis, occurs in post-cardiac arrest patients and that better microcirculatory flow will be associated with improved outcome. We also assessed the association between microcirculatory dysfunction and inflammatory...... markers in the post-cardiac arrest state. METHODS: We prospectively evaluated the sublingual microcirculation in post-cardiac arrest patients, severe sepsis/septic shock patients, and healthy control patients using Sidestream Darkfield microscopy. Microcirculatory flow was assessed using...... the microcirculation flow index (MFI) at 6 and 24h in the cardiac arrest patients, and within 6h of emergency department admission in the sepsis and control patients. RESULTS: We evaluated 30 post-cardiac arrest patients, 16 severe sepsis/septic shock patients, and 9 healthy control patients. Sublingual...

  8. Clinical effectiveness of centrifugal pump to produce pulsatile flow during cardiopulmonary bypass in patients undergoing cardiac surgery.

    Science.gov (United States)

    Gu, Y John; van Oeveren, Willem; Mungroop, Hubert E; Epema, Anne H; den Hamer, Inez J; Keizer, Jorrit J; Leuvenink, Ron P; Mariani, Massimo A; Rakhorst, Gerhard

    2011-02-01

    Although the centrifugal pump has been widely used as a nonpulsatile pump for cardiopulmonary bypass (CPB), little is known about its performance as a pulsatile pump for CPB, especially on its efficacy in producing hemodynamic energy and its clinical effectiveness. We performed a study to evaluate whether the Rotaflow centrifugal pump produces effective pulsatile flow during CPB and whether the pulsatile flow in this setting is clinically effective in adult patients undergoing cardiac surgery. Thirty-two patients undergoing CPB for elective coronary artery bypass grafting were randomly allocated to a pulsatile perfusion group (n = 16) or a nonpulsatile perfusion group (n = 16). All patients were perfused with the Rotaflow centrifugal pump. In the pulsatile group, the centrifugal pump was adjusted to the pulsatile mode (60 cycles/min) during aortic cross-clamping, whereas in the nonpulsatile group, the pump was kept in its nonpulsatile mode during the same period of time. Compared with the nonpulsatile group, the pulsatile group had a higher pulse pressure (P centrifugal pump is associated with a small gain of EEP and SHE, which does not seem to be clinically effective in adult cardiac surgical patients.

  9. 心腔流场可视化的超声观察%Ultrasonic Visualization of Cardiac Flow Field

    Institute of Scientific and Technical Information of China (English)

    唐红; 陈柳; 韦馨

    2012-01-01

      This paper introduced a concept of flow field and research technique for cardiac flow field. We mailnly reviewed the clinical application of vector flow mapping (VFM) on the Left ventricular diastolic and systolic flow transition,flow pattern in right atrium,pulmonary vein,left auricle and aortic arch.The quantification of aortic regurgitation,feasibility and accuracy of VFM in Qp/Qs was analyzed. Left Ventricular Vortex Analysis in ASD and PDA Patients was evaluated.%  本文简介了流场的概念以及心腔流场的研究技术,着重介绍了血流向量成像技术(VFM)的临床应用,包括左心室流场、右心房流场、肺静脉流场、左心耳流场、主动脉弓流场的观察,主动脉瓣反流的定量评估,定量体肺流量比Qp/Qs的准确性,评价房间隔缺损(ASD)、动脉导管未闭(PDA)患者左室腔涡流特征等。

  10. Debris Flow Hazard Assessment Based on Support Vector Machine

    Institute of Scientific and Technical Information of China (English)

    YUAN Lifeng; ZHANG Youshui

    2006-01-01

    Seven factors, including the maximum volume of once flow , occurrence frequency of debris flow , watershed area , main channel length , watershed relative height difference , valley incision density and the length ratio of sediment supplement are chosen as evaluation factors of debris flow hazard degree. Using support vector machine (SVM) theory, we selected 259 basic data of 37 debris flow channels in Yunnan Province as learning samples in this study. We create a debris flow hazard assessment model based on SVM. The model was validated though instance applications and showed encouraging results.

  11. Cardiac CT for the assessment of chest pain: Imaging techniques and clinical results

    Energy Technology Data Exchange (ETDEWEB)

    Becker, Hans-Christoph, E-mail: christoph.becker@med.uni-muenchen.de [Ludwig-Maximilians-University, Grosshadern Clinic, Department of Clinical Radiology, Marchioninistr. 15, 81377 Munich (Germany); Johnson, Thorsten [Ludwig-Maximilians-University, Grosshadern Clinic, Department of Clinical Radiology, Marchioninistr. 15, 81377 Munich (Germany)

    2012-12-15

    Immediate and efficient risk stratification and management of patients with acute chest pain in the emergency department is challenging. Traditional management of these patients includes serial ECG, laboratory tests and further on radionuclide perfusion imaging or ECG treadmill testing. Due to the advances of multi-detector CT technology, dedicated coronary CT angiography provides the potential to rapidly and reliably diagnose or exclude acute coronary artery disease. Life-threatening causes of chest pain, such as aortic dissection and pulmonary embolism can simultaneously be assessed with a single scan, sometimes referred to as “triple rule out” scan. With appropriate patient selection, cardiac CT can accurately diagnose heart disease or other sources of chest pain, markedly decrease health care costs, and reliably predict clinical outcomes. This article reviews imaging techniques and clinical results for CT been used to evaluate patients with chest pain entering the emergency department.

  12. Feasibility of measuring superior mesenteric artery blood flow during cardiac surgery under hypothermic cardiopulmonary bypass using transesophageal echocardiography: An observational study

    Directory of Open Access Journals (Sweden)

    Naveen G Singh

    2016-01-01

    Full Text Available Background: Abdominal complications being rare but results in high mortality, commonly due to splanchnic organ hypoperfusion during the perioperative period of cardiac surgery. There are no feasible methods to monitor intraoperative superior mesenteric artery blood flow (SMABF. Hence, the aim of this study was to evaluate the feasibility and to measure SMABF using transesophageal echocardiography (TEE during cardiac surgery under hypothermic cardiopulmonary bypass (CPB. Methodology: Thirty-five patients undergoing elective cardiac surgery under CPB were enrolled. Heart rate, mean arterial pressure (MAP, cardiac output (CO, SMABF, superior mesenteric artery (SMA diameter, superior mesentric artery blood flow over cardiac output (SMA/CO ratio and arterial blood lactates were recorded at three time intervals. T0: before sternotomy, T1: 30 min after initiation of CPB and T2: after sternal closure. Results: SMA was demonstrated in 32 patients. SMABF, SMA diameter, SMA/CO, MAP and CO-decreased significantly (P 0.05 between T0 and T2. Lactates increased progressively from T0 to T2. Conclusion: Study shows that there is decrease in SMABF during CPB and returns to baseline after CPB. Hence, it is feasible to measure SMABF using TEE in patients undergoing cardiac surgery under hypothermic CPB. TEE can be a promising tool in detecting and preventing splanchnic hypoperfusion during perioperative period.

  13. Novel phase-based noise reduction strategy for quantification of left ventricular function and mass assessment by cardiac CT: Comparison with cardiac magnetic resonance

    Energy Technology Data Exchange (ETDEWEB)

    Wai, Bryan, E-mail: bwai@partners.org [Cardiac MR PET CT Program, Division of Cardiology and Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts (United States); Thai, Wai-ee [Cardiac MR PET CT Program, Division of Cardiology and Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts (United States); Brown, Heather [Qi Imaging, Redwood City, California (United States); Truong, Quynh A. [Cardiac MR PET CT Program, Division of Cardiology and Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts (United States)

    2013-08-15

    Background: Tube current modulation in retrospective ECG gated cardiac computed tomography (CT) results in increased image noise and may reduce the accuracy of left ventricular (LV) ejection fraction (EF) and mass assessment. Objective: To examine the effects of a novel CT phase-based noise reduction (NR) algorithm on LV EF and mass quantification as compared to cardiac magnetic resonance (CMR). Methods: In 40 subjects, we compared the LV EF and mass between CT and CMR. In a subset of 24 subjects with tube current modulated CT, the effect of phase-based noise reduction strategies on contrast-to-noise ratio (CNR) and the assessment of LV EF and mass was compared to CMR. Results: There was excellent correlation between CT and CMR for EF (r = 0.94) and mass (r = 0.97). As compared to CMR, the limits of agreement improved with increasing strength of NR strategy. There was a systematic underestimation of LV mass by CT compared to CMR with no NR (−10.3 ± 10.1 g) and low NR (−10.3 ± 12.5 g), but was attenuated with high NR (−0.5 ± 8.3 g). Studies without NR had lower CNR compared to low and high NR at both the ES phase and ED phase (all p < 0.01). Conclusions: A high NR strategy on tube current modulated functional cardiac CT improves correlation of EF compared to CMR and reduces variability of EF and mass evaluation by increasing the CNR. In an effort to reduce radiation dose with tube current modulation, this strategy provides better image quality when LV function and mass quantification is needed.

  14. A new non-invasive statistical method to assess the spontaneous cardiac baroreflex in humans.

    Science.gov (United States)

    Ducher, M; Fauvel, J P; Gustin, M P; Cerutti, C; Najem, R; Cuisinaud, G; Laville, M; Pozet, N; Paultre, C Z

    1995-06-01

    1. A new method was developed to evaluate cardiac baroreflex sensitivity. The association of a high systolic blood pressure with a low heart rate or the converse is considered to be under the influence of cardiac baroreflex activity. This method is based on the determination of the statistical dependence between systolic blood pressure and heart rate values obtained non-invasively by a Finapres device. Our computerized analysis selects the associations with the highest statistical dependence. A 'Z-coefficient' quantifies the strength of the statistical dependence. The slope of the linear regression, computed on these selected associations, is used to estimate baroreflex sensitivity. 2. The present study was carried out in 11 healthy resting male subjects. The results obtained by the 'Z-coefficient' method were compared with those obtained by cross-spectrum analysis, which has already been validated in humans. Furthermore, the reproducibility of both methods was checked after 1 week. 3. The results obtained by the two methods were significantly correlated (r = 0.78 for the first and r = 0.76 for the second experiment, P < 0.01). When repeated after 1 week, the average results were not significantly different. Considering individual results, test-retest correlation coefficients were higher with the Z-analysis (r = 0.79, P < 0.01) than with the cross-spectrum analysis (r = 0.61, P < 0.05). 4. In conclusion, as the Z-method gives results similar to but more reproducible than the cross-spectrum method, it might be a powerful and reliable tool to assess baroreflex sensitivity in humans.

  15. GULLY-SPECIFIC DEBRIS FLOW HAZARD ASSESSMENT IN CHINA

    Institute of Scientific and Technical Information of China (English)

    LIU Xi-lin

    2003-01-01

    Techniques of gully-specific debris flow hazard assessment developed in four periods since the end of the1980s have been discussed in the present paper. The improvement for the empirical assessment method is the sectional-ized function transformation for the factor value, rather than the classified logical transformation. The theoretical equationof the gully-specific debris flow hazard is expressed as the definite integral of an exponential function and its numericalsolution is expressed by the Poisson Limit Equation. Current methods for assessment of debris flow hazard in China arestill valid and practical. The further work should be put on the study of the reliability (or unc ertainty) of the techniques.For the future, we should give a high priority to the relationship between debris flow magnitude and its frequency of occur-rence, make more developments of prediction model on debris flow magnitude, so as to finally reach the goal of assessingthe hazard of debris flow by theoretical model, and realize both actuality assessment and prediction appraisal of debris flow.

  16. Prehospital randomised assessment of a mechanical compression device in cardiac arrest (PaRAMeDIC trial protocol

    Directory of Open Access Journals (Sweden)

    McCabe Chris

    2010-11-01

    Full Text Available Abstract Background Survival after out-of-hospital cardiac arrest is closely linked to the quality of CPR, but in real life, resuscitation during prehospital care and ambulance transport is often suboptimal. Mechanical chest compression devices deliver consistent chest compressions, are not prone to fatigue and could potentially overcome some of the limitations of manual chest compression. However, there is no high-quality evidence that they improve clinical outcomes, or that they are cost effective. The Prehospital Randomised Assessment of a Mechanical Compression Device In Cardiac Arrest (PARAMEDIC trial is a pragmatic cluster randomised study of the LUCAS-2 device in adult patients with non-traumatic out-of-hospital cardiac arrest. Methods/design The primary objective of this trial is to evaluate the effect of chest compression using LUCAS-2 on mortality at 30 days post out-of-hospital cardiac arrest, compared with manual chest compression. Secondary objectives of the study are to evaluate the effects of LUCAS-2 on survival to 12 months, cognitive and quality of life outcomes and cost-effectiveness. Methods: Ambulance service vehicles will be randomised to either manual compression (control or LUCAS arms. Adult patients in out-of-hospital cardiac arrest, attended by a trial vehicle will be eligible for inclusion. Patients with traumatic cardiac arrest or who are pregnant will be excluded. The trial will recruit approximately 4000 patients from England, Wales and Scotland. A waiver of initial consent has been approved by the Research Ethics Committees. Consent will be sought from survivors for participation in the follow-up phase. Conclusion The trial will assess the clinical and cost effectiveness of the LUCAS-2 mechanical chest compression device. Trial Registration: The trial is registered on the International Standard Randomised Controlled Trial Number Registry (ISRCTN08233942.

  17. A multi-region assessment of population rates of cardiac catheterization and yield of high-risk coronary artery disease

    Directory of Open Access Journals (Sweden)

    Clement Fiona M

    2011-11-01

    Full Text Available Abstract Background There is variation in cardiac catheterization utilization across jurisdictions. Previous work from Alberta, Canada, showed no evidence of a plateau in the yield of high-risk disease at cardiac catheterization rates as high as 600 per 100,000 population suggesting that the optimal rate is higher. This work aims 1 To determine if a previously demonstrated linear relationship between the yield of high-risk coronary disease and cardiac catheterization rates persists with contemporary data and 2 to explore whether the linear relationship exists in other jurisdictions. Methods Detailed clinical information on all patients undergoing cardiac catheterization in 3 Canadian provinces was available through the Alberta Provincial Project for Outcomes Assessment in Coronary Heart (APPROACH disease and partner initiatives in British Columbia and Nova Scotia. Population rates of catheterization and high-risk coronary disease detection for each health region in these three provinces, and age-adjusted rates produced using direct standardization. A mixed effects regression analysis was performed to assess the relationship between catheterization rate and high-risk coronary disease detection. Results In the contemporary Alberta data, we found a linear relationship between the population catheterization rate and the high-risk yield. Although the yield was slightly less in time period 2 (2002-2006 than in time period 1(1995-2001, there was no statistical evidence of a plateau. The linear relationship between catheterization rate and high-risk yield was similarly demonstrated in British Columbia and Nova Scotia and appears to extend, without a plateau in yield, to rates over 800 procedures per 100,000 population. Conclusions Our study demonstrates a consistent finding, over time and across jurisdictions, of linearly increasing detection of high-risk CAD as population rates of cardiac catheterization increase. This internationally-relevant finding

  18. Cardiac sympathetic denervation in familial amyloid polyneuropathy assessed by iodine-123 metaiodobenzylguanidine scintigraphy and heart rate variability

    Energy Technology Data Exchange (ETDEWEB)

    Delahaye, N.; Le Guludec, D. [Department of Nuclear Medicine, Bichat Hospital, Paris (France); Dinanian, S.; Slama, M.S. [Department of Cardiology, A. Beclere Hospital, Paris (France); Mzabi, H.; Samuel, D. [Department of Hepatic Surgery, P. Brousse Hospital, Paris (France); Adams, D. [Department of Neurology, Bicetre Hospital, Paris (France); Merlet, P. [SHFJ, DSV-CEA, Orsay (France)

    1999-04-29

    Familial amyloid polyneuropathy (FAP) is a rare and severe hereditary form of amyloidosis, due to nervous deposits of a genetic variant transthyretin produced by the liver and characterized by both sensorimotor and autonomic neuropathy. Left ventricular systolic dysfunction is rare, but conduction disturbances and sudden deaths can occur. The neurological status of the heart has not been elucidated, and an alteration of the sympathetic nerves may be involved. We studied 17 patients (42{+-}12 years) before liver transplantation by iodine-123 metaiodobenzylguanidine (MIBG) scintigraphy, heart rate variability analysis, coronary angiography, radionuclide ventriculography, rest thallium single-photon emission tomography (SPET) and echocardiography. Coronary arteries, left ventricular systolic function and rest thallium SPET were normal in all patients. Only mild evidence of amyloid infiltration was found at echocardiographic examination. Cardiac MIBG uptake was dramatically decreased in patients compared with age-matched control subjects (heart-to-mediastinum activity ratio at 4 h: 1.36{+-}0.26 versus 1.98{+-}0.35, P<0.001), while there was no difference in MIBG washout rate. Heart rate variability analysis showed a considerable scatter of values, with high values in four patients despite cardiac sympathetic denervation as assessed by MIBG imaging. The clinical severity of the polyneuropathy correlated with MIBG uptake at 4 h but not with the heart rate variability indices. Cardiac MIBG uptake and the heart rate variability indices did not differ according to the presence or absence of conduction disturbances. Patients with FAP have sympathetic cardiac denervation as assessed by MIBG imaging despite a preserved left ventricular systolic function and cardiac perfusion, without correlation with conduction disturbances. Results of the heart rate variability analysis were more variable and this technique does not seem to be the best way to evaluate the extent of cardiac

  19. INFLUENCE OF MIMIC CARDIAC RATE ON HYDRODYNAMICS OF DIFFERENT MECHANICAL PROSTHETIC CARDIAC VALVES IN VITRO

    Institute of Scientific and Technical Information of China (English)

    Yin-ping Chu; Jin-lian Cheng; Ru-kun Chen; Yu-bo Fan; Fang Pu

    2005-01-01

    Objective To assess the influence of mimic cardiac rate on hydrodynamics of different mechanical prosthetic cardiac valves.Methods US-made CarboMedics bileaflet valve, China-made Jiuling bileaflet valve and C-L tilting disc valve were tested via a pulsatile flow simulator in the aortic position. Testing conditions were set at mimic cardiac rates of 55 bpm, 75 bpm, 100bpm with a constant mimic cardiac output of 4 L/min. The mean pressure differences (△P), leakage volumes (LEV) and closing volumes (CLV) across each valve, and effective orifice areas (EOA) were analyzed.Results Within physiological range, △p, LEV, and CLV decreased as mimic cardiac rate increased, with a large extent of variance. EOA increased along with an increase in mimic cardiac rate. It was a different response in terms of cardiac rate alteration for different types of mechanical prosthetic cardiac valves.Conclusion Mimic cardiac rate change affects hydrodynamics of mechanical prosthetic cardiac valves. Within physiological range, the hydrodynamic of prosthetic bileaflet valve is better than that of tilting disc valve.

  20. Cardiac injuries caused by blunt trauma: an autopsy based assessment of the injury pattern.

    Science.gov (United States)

    Turan, Arzu Akcay; Karayel, Ferah Anik; Akyildiz, Elif; Pakis, Isil; Uzun, Ibrahim; Gurpinar, Kagan; Atilmis, Umit; Kir, Ziya

    2010-01-01

    Nonpenetrating chest trauma with injury to the heart and aorta has become increasingly common, particularly as a result of rapid deceleration in high-speed vehicular accidents, over the past 2-3 decades. The high mortality rate of cardiac injuries and possible late onset complications make blunt cardiac injuries an important challenging point for legal medicine. One hundred and ninety cases with blunt cardiac injuries in a period of 3 years were analyzed retrospectively in terms of patterns of cardiac injury, survival times, and demographic profiles of the cases in this study.

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

    Science.gov (United States)

    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.

  2. MERCOSUR DEVELOPMENT: AN ASSESSMENT OF TRADE FLOWS

    Directory of Open Access Journals (Sweden)

    Rubiane Daniele Cardoso

    2016-05-01

    Full Text Available This paper search to analyze the effects of the formation of Mercosur Preferential Trade Agreement trade flows of member countries in the 1994-2009 period, using an extended gravity model that includes dummy variables for Mercosur, for UE and NAFTA (importants economic blocs, for the sectors of the economy and member country. The results show that Mercosur obtained the largest increases in trade among all regional integration schemes relevant to member countries, which highlights its importance for the members. When considering the analysis of the sectors, only agriculture had significant value, showing that the products were still predominant in this sector in the export of the Mercosur countries to all countries in the sample both in 1994, as in 2009.

  3. Environmental flow assessment for river Trebizat, BiH

    Science.gov (United States)

    Smolar-Zvanut, N.; Kupusovic, E.; Vucijak, B.; Mijatovic, A.; Grizelj, Z.; Antonelli, F.

    2009-04-01

    The alteration of the water flow downstream of dams is one of the most stressful factors influencing the aquatic and riverine ecosystem. The environmental flow assessment is a tool for finding the balance between water use by humans and nature and ensuring a long-term and good quality water supply both for human purposes and for ecosystems. In 2007/08 WWF has implemented a project in the Neretva basin (Bosnia and Herzegovina) with a focus on environmental flow evaluation for the river Trebizat, located in the western region of Herzegovina. The water regime of the Trebizat river is affected by the abstraction of its water for hydropower plants, irrigation and fish farming not to mention pollution problems. The Trebizat river flows through an area of remarkable ecological value hosting also protected areas (the travertine-formation around Kravice waterfall). The main aim of this paper is to present the results of the application of a methodology for environmental flow assessment, namely the GEP methodology (guaranteed ecological flow). It belongs to the category of hydrological environmental flow assessment methods and the test was done to assess the environmental flow in the river Trebizat. Using existing hydrological data as well as samples specifically collected on the field, the environmental flow was assessed applying the GEP methodology. Additionally, instream ecological values and critical parameters for environmental flow assessment were evaluated. The area was assessed in terms of its geography, climate conditions, historic heritage of the river, demography, geology of the river and its tributaries, river hydrology and morphology, ecological characteristics, river pollution, river use and river management. At five selected sampling sites along the Trebizat river, additional data on macrophytes, phytobenthos and physico-chemical parameters were collected and analysed. Although there have been many negative impacts in recent years on the Trebizat river, the

  4. Assessment of cardiac function by magnetic resonance imaging: segmented versus real time steady-state free precession sequences

    Energy Technology Data Exchange (ETDEWEB)

    Bezerra, Leonardo Bernardo [Rio Grande do Norte Univ., Natal, RN (Brazil)]. E-mail: warrenhellwind@yahoo.com.br; Marchiori, Edson; Pontes, Paulo V. [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Dept. de Radiologia

    2006-09-15

    Objective: to compare ventricular systolic parameters on segmented and real-time steady-state free precession cine-MRI sequences and ECG-gated MRI in patients presenting or not with cardiac arrhythmias. Materials and methods: ejection fraction and end-diastolic/end-systolic volumes have been compared in 31 patients, 11 presenting with cardiac arrhythmias, and 20 with regular sinus rhythm, using ECG-gated segmented and real-time sequences. The statistical analysis was performed using Pearson's correlation and Bland-Altman agreement plot, with p < 0.01. Results: real-time acquisitions demonstrated endocardial borders blurring effects, but both sequences presented a clear, positive correlation: ejection fraction r = 0.94; end-diastolic volume r = 0.93 and end-systolic volume r 0.98. The assessment of 11 patients with arrhythmias has not demonstrated a statistically significant difference, despite the lower blood pool-myocardial contrast ratio. Conclusion: real-time sequences may be utilized for cardiac function assessment, regardless the patient's cardiac rhythm. (author)

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

    Science.gov (United States)

    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.

  6. Vulnerability Assessment of Rainfall-Induced Debris Flow

    Science.gov (United States)

    Lu, G. Y.; Wong, D. W.; Chiu, L. S.

    2006-05-01

    Debris flow is a common hazard triggered by large amount of rainfall over mountainous areas. A debris flow event results from a complex interaction between rainfall and topographical properties of watersheds. Heavy rainfall facilitates this process by increasing pore water pressure, seepage force and reducing effective stress of soils (normal stress carried by soil particles at the points of contact). Since debris flow events are closely related to topography and rainfall, the goal of this research is to assess debris flow vulnerability related to these two factors. Objectives of this research are to: (1) examine new spatial interpolation techniques to estimate high spatial rainfall data relevant to debris flows. (2) develop topographical factors using Geography Information System (GIS) and remote sensing (RS) approaches and (3) combine the estimated rainfall and topographical factors to assess the vulnerability of debris flow. We examined three spatial interpolation techniques: adaptive inversed distance weight (AIDW), simple kriging and spatial disaggregation using wind induced-topographic effect that incorporates gauge measurements, satellite remote sensing data (TRMM). The topographical factors are derived from high resolution digital elevation model (DEM), and adopt fuzzy-based topographical models proposed by Tseng (2004). Estimated rainfall and topographical factors are processed by self-organizing maps (SOM) to provide vulnerability assessment. To demonstrate our technique, rainfall data collected by 39 rain gauges in the central part of Taiwan during the passage of Typhoon Tori-Ji around July 29, 2001 were used. Results indicate that the proposed spatial interpolation methods outperform existing methods (i.e. kriging, inverse distance weight, and co-kriging methods). The vulnerability assessment of 187 debris flows watersheds in the study area will be presented. Keyword: Debris flow, spatial interpolation, adaptive inverse distance weight, TRMM, self

  7. Cardiac Abnormalities in Adult Patients With Polymyositis or Dermatomyositis as Assessed by Noninvasive Modalities

    DEFF Research Database (Denmark)

    Diederichsen, L P; Simonsen, J A; Diederichsen, A C

    2016-01-01

    OBJECTIVE: Cardiac events are a major cause of death in patients with idiopathic inflammatory myopathies. The study objective was in a controlled setting to describe cardiac abnormalities by noninvasive methods in a cohort of patients with polymyositis (PM) or dermatomyositis (DM) and to identify...

  8. The effect of Glucagon-Like Peptide-2 on mesenteric blood flow and cardiac parameters in end-jejunostomy short bowel patients

    DEFF Research Database (Denmark)

    Bremholm, Lasse; Hornum, Mads; Andersen, Ulrik B;

    2011-01-01

    Exogenous Glucagon-Like Peptide-2 (GLP-2) treatment improves intestinal wet weight absorption in short bowel syndrome (SBS) patients. In healthy subjects, administration of GLP-2 increases small intestinal blood flow. The aim of the study was to evaluate the effect of GLP-2 on mesenteric blood flow...... and dynamic changes in cardiac parameters in SBS patients with jejunostomy and varying length of remnant small intestine....

  9. Cerebral blood flow assessment of preterm infants during respiratory therapy with the expiratory flow increase technique

    Directory of Open Access Journals (Sweden)

    Mariana Almada Bassani

    2016-06-01

    Full Text Available Abstract Objective: To assess the impact of respiratory therapy with the expiratory flow increase technique on cerebral hemodynamics of premature newborns. Methods: This is an intervention study, which included 40 preterm infants (≤34 weeks aged 8-15 days of life, clinically stable in ambient air or oxygen catheter use. Children with heart defects, diagnosis of brain lesion and/or those using vasoactive drugs were excluded. Ultrasonographic assessments with transcranial Doppler flowmetry were performed before, during and after the increase in expiratory flow session, which lasted 5min. Cerebral blood flow velocity and resistance and pulsatility indices in the pericallosal artery were assessed. Results: Respiratory physical therapy did not significantly alter flow velocity at the systolic peak (p=0.50, the end diastolic flow velocity (p=0.17, the mean flow velocity (p=0.07, the resistance index (p=0.41 and the pulsatility index (p=0.67 over time. Conclusions: The expiratory flow increase technique did not affect cerebral blood flow in clinically-stable preterm infants.

  10. Assessment of cardiac sympathetic nerve activity in children with chronic heart failure using quantitative iodine-123 metaiodobenzylguanidine imaging

    Energy Technology Data Exchange (ETDEWEB)

    Karasawa, Kensuke; Ayusawa, Mamoru; Noto, Nobutaka; Sumitomo, Naokata; Okada, Tomoo; Harada, Kensuke [Nihon Univ., Tokyo (Japan). School of Medicine

    2000-12-01

    Cardiac sympathetic nerve activity in children with chronic heart failure was examined by quantitative iodine-123 metaiodobenzylguanidine (MIBG) myocardial imaging in 33 patients aged 7.5{+-}6.1 years (range 0-18 years), including 8 with cardiomyopathy, 15 with congenital heart disease, 3 with anthracycrine cardiotoxicity, 3 with myocarditis, 3 with primary pulmonary hypertension and 1 with Pompe's disease. Anterior planar images were obtained 15 min and 3 hr after the injection of iodine-123 MIBG. The cardiac iodine-123 MIBG uptake was assessed as the heart to upper mediastinum uptake activity ratio of the delayed image (H/M) and the cardiac percentage washout rate (%WR). The severity of chronic heart failure was class I (no medication) in 8 patients, class II (no symptom with medication) in 9, class III (symptom even with medication) in 10 and class IV (late cardiac death) in 6. H/M was 2.33{+-}0.22 in chronic heart failure class I, 2.50{+-}0.34 in class II, 1.95{+-}0.61 in class III, and 1.39{+-}0.29 in class IV (p<0.05). %WR was 24.8{+-}12.8% in chronic heart failure class I, 23.3{+-}10.2% in class II, 49.2{+-}24.5% in class III, and 66.3{+-}26.5% in class IV (p<0.05). The low H/M and high %WR were proportionate to the severity of chronic heart failure. Cardiac iodine-123 MIBG showed cardiac adrenergic neuronal dysfunction in children with severe chronic heart failure. Quantitative iodine-123 MIBG myocardial imaging is clinically useful as a predictor of therapeutic outcome and mortality in children with chronic heart failure. (author)

  11. Cerebral blood flow during cardiopulmonary bypass in pediatric cardiac surgery: the role of transcranial Doppler – a systematic review of the literature

    Directory of Open Access Journals (Sweden)

    Sanders Stephen P

    2006-12-01

    Full Text Available Abstract Background Transcranial Doppler Ultrasound (TCD is a sensitive, real time tool for monitoring cerebral blood flow velocity (CBFV. This technique is fast, accurate, reproducible and noninvasive. In the setting of congenital heart surgery, TCD finds application in the evaluation of cerebral blood flow variations during cardiopulmonary bypass (CPB. Methodology We performed a search on human studies published on the MEDLINE using the keyword "trans cranial Doppler" crossed with "pediatric cardiac surgery" AND "cardio pulmonary by pass", OR deep hypothermic cardiac arrest", OR "neurological monitoring". Discussion Current scientific evidence suggests a good correlation between changes in cbral blood flow and mean cerebral artery (MCA blood flow velocity. The introduction of Doppler technology has allowed an accurate monitorization of cerebral blood flow (CBF during circulatory arrest and low-flow CPB. TCD has also been utilized in detecting cerebral emboli, improper cannulation or cross clamping of aortic arch vessels. Limitations of TCD routine utilization are represented by the need of a learning curve and some experience by the operators, as well as the need of implementing CBF informations with, for example, data on brain tissue oxygen delivery and consumption. Conclusion In this light, TCD plays an essential role in multimodal neurological monitorization during CPB (Near Infrared Spectroscopy, TCD, processed electro encephalography that, according to recent studies, can help to significantly improve neurological outcome after cardiac surgery in neonates and pediatric patients.

  12. Left ventricular flow analysis: recent advances in numerical methods and applications in cardiac ultrasound.

    Science.gov (United States)

    Borazjani, Iman; Westerdale, John; McMahon, Eileen M; Rajaraman, Prathish K; Heys, Jeffrey J; Belohlavek, Marek

    2013-01-01

    The left ventricle (LV) pumps oxygenated blood from the lungs to the rest of the body through systemic circulation. The efficiency of such a pumping function is dependent on blood flow within the LV chamber. It is therefore crucial to accurately characterize LV hemodynamics. Improved understanding of LV hemodynamics is expected to provide important clinical diagnostic and prognostic information. We review the recent advances in numerical and experimental methods for characterizing LV flows and focus on analysis of intraventricular flow fields by echocardiographic particle image velocimetry (echo-PIV), due to its potential for broad and practical utility. Future research directions to advance patient-specific LV simulations include development of methods capable of resolving heart valves, higher temporal resolution, automated generation of three-dimensional (3D) geometry, and incorporating actual flow measurements into the numerical solution of the 3D cardiovascular fluid dynamics.

  13. Current Imaging Modalities for assessing Ocular Blood Flow in Glaucoma

    OpenAIRE

    Mohindroo, Chirayu; Ichhpujani, Parul; Kumar, Suresh

    2016-01-01

    Glaucoma may be caused by an interplay of elevated intraocular pressure (IOP), vascular, genetic, anatomical, brain, and immune factors. The direct assessment of ocular hemodynam-ics offers promise for glaucoma detection, differentiation, and possibly new treatment modalities. All the methods currently in use to measure ocular blood flow have inherent limitations and measure different aspects of ocular blood flow. This review article attempts to provide detailed information on ocular perfu-si...

  14. Functional cardiac MRI for assessment of aortic valve disease; Aortenklappenstenose im MRT mit Dynamik und 3D

    Energy Technology Data Exchange (ETDEWEB)

    Sagmeister, F.; Ritter, C.; Machann, W.; Koestler, H.; Hahn, D.; Beer, M. [Universitaetsklinikum Wuerzburg, Institut fuer Roentgendiagnostik, Wuerzburg (Germany); Herrmann, S.; Voelker, W.; Weidemann, F. [Universitaetsklinikum Wuerzburg, Medizinische Klinik I, Wuerzburg (Germany)

    2010-06-15

    Aortic valve disease shows a rising incidence with the increasing mean age of Western populations. The detection of hemodynamic parameters, which transcends the mere assessment of valve morphology, has an important future potential concerning classification of the severity of disease. MRI allows a non-invasive and a spatially flexible view of the aortic valve and the adjacent anatomic region, left ventricular outflow tract (LVOT) and ascending aorta. Moreover, the technique allows the determination of functional hemodynamic parameters, such as flow velocities and effective orifice areas. The new approach of a serial systolic planimetry velocity-encoded MRI sequence (VENC-MRI) facilitates the sizing of blood-filled cardiac structures with the registration of changes in magnitude during systole. Additionally, the subvalvular VENC-MRI measurements improve the clinically important exact determination of the LVOT area with respect to its specific eccentric configuration and its systolic deformity. (orig.) [German] Erworbene Erkrankungen der Aortenklappe wie die Aortenklappenstenose zeigen mit zunehmender Alterungstendenz unserer Gesellschaft eine ansteigende Inzidenz. Die Erfassung ueber die reine Klappenmorphologie hinausgehender haemodynamischer Parameter hat ein wichtiges zukuenftiges Potenzial zur Schweregradeinschaetzung. Die MRT erlaubt eine nichtinvasive und raeumlich flexible Darstellung der Aortenklappe sowie ihrer benachbarten anatomischen Strukturen (linksventrikulaerer Ausflusstrakt/LVOT, Aorta ascendens). Darueber hinaus ist eine Bestimmung funktioneller haemodynamischer Parameter wie Flussgeschwindigkeiten und effektiven Oeffnungsflaechen (EOeF) moeglich. Der neue Ansatz einer seriellen Planimetrie geschwindigkeitskodierter MRT-Sequenzen (Velocity-encoding- [VENC-]MRT) erlaubt die Groessenbestimmung flussdurchstroemter kardialer Strukturen und die Aufzeichnung ihrer dynamischen Groessenveraenderung waehrend der Systole. Zusaetzlich ermoeglicht die

  15. Research on Standard Flow for materials life cycle assessment

    Institute of Scientific and Technical Information of China (English)

    DI Xiang-hua; NIE Zuo-ren; WANG Zhi-hong; ZUO Tie-yong

    2004-01-01

    For the sake of objectivity of the interpretation in life cycle assessment (LCA), the concept and the design proposal of Standard Flow were put forward. Standard Flow was defined as the collection of related environmental load parameters that represent the specific development degree of certain industrial process(es) by the function unit. A novel methodological approach called the Standard Flow Comparing, was developed for LCA. The indicator for potential of process improvement and its weighting factor were derived. To a certain degree the problem of the identification and selection of process development objects in LCA was solved. The concept of Standard Flow and the method of Standard Flow Comparing are introduced, formulized and analyzed.

  16. Canadian Cardiovascular Society Guidelines on Perioperative Cardiac Risk Assessment and Management for Patients Who Undergo Noncardiac Surgery.

    Science.gov (United States)

    Duceppe, Emmanuelle; Parlow, Joel; MacDonald, Paul; Lyons, Kristin; McMullen, Michael; Srinathan, Sadeesh; Graham, Michelle; Tandon, Vikas; Styles, Kim; Bessissow, Amal; Sessler, Daniel I; Bryson, Gregory; Devereaux, P J

    2017-01-01

    The Canadian Cardiovascular Society Guidelines Committee and key Canadian opinion leaders believed there was a need for up to date guidelines that used the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system of evidence assessment for patients who undergo noncardiac surgery. Strong recommendations included: 1) measuring brain natriuretic peptide (BNP) or N-terminal fragment of proBNP (NT-proBNP) before surgery to enhance perioperative cardiac risk estimation in patients who are 65 years of age or older, are 45-64 years of age with significant cardiovascular disease, or have a Revised Cardiac Risk Index score ≥ 1; 2) against performing preoperative resting echocardiography, coronary computed tomography angiography, exercise or cardiopulmonary exercise testing, or pharmacological stress echocardiography or radionuclide imaging to enhance perioperative cardiac risk estimation; 3) against the initiation or continuation of acetylsalicylic acid for the prevention of perioperative cardiac events, except in patients with a recent coronary artery stent or who will undergo carotid endarterectomy; 4) against α2 agonist or β-blocker initiation within 24 hours before surgery; 5) withholding angiotensin-converting enzyme inhibitor and angiotensin II receptor blocker starting 24 hours before surgery; 6) facilitating smoking cessation before surgery; 7) measuring daily troponin for 48 to 72 hours after surgery in patients with an elevated NT-proBNP/BNP measurement before surgery or if there is no NT-proBNP/BNP measurement before surgery, in those who have a Revised Cardiac Risk Index score ≥1, age 45-64 years with significant cardiovascular disease, or age 65 years or older; and 8) initiating of long-term acetylsalicylic acid and statin therapy in patients who suffer myocardial injury/infarction after surgery.

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

    Energy Technology Data Exchange (ETDEWEB)

    Cros, C., E-mail: caroline.cros@hotmail.co.uk [Safety Pharmacology, Global Safety Assessment, Safety Assessment UK, AstraZeneca R and D, Alderley Park, Macclesfield, SK10 4TG (United Kingdom); Skinner, M., E-mail: Matthew.Skinner@astrazeneca.com [Safety Pharmacology, Global Safety Assessment, Safety Assessment UK, AstraZeneca R and D, Alderley Park, Macclesfield, SK10 4TG (United Kingdom); Moors, J. [Safety Pharmacology, Global Safety Assessment, Safety Assessment UK, AstraZeneca R and D, Alderley Park, Macclesfield, SK10 4TG (United Kingdom); Lainee, P. [Sanofi-Aventis R and D, 371, rue du Pr Joseph Blayac, 34184 Montpellier Cedex 04 (France); Valentin, J.P. [Safety Pharmacology, Global Safety Assessment, Safety Assessment UK, AstraZeneca R and D, Alderley Park, Macclesfield, SK10 4TG (United Kingdom)

    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

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

    Directory of Open Access Journals (Sweden)

    Ghulam Murtaza

    2016-03-01

    Full Text Available 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.

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

    Science.gov (United States)

    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.

  20. Pulmonary Artery Catheter (PAC Accuracy and Efficacy Compared with Flow Probe and Transcutaneous Doppler (USCOM: An Ovine Cardiac Output Validation

    Directory of Open Access Journals (Sweden)

    Robert A. Phillips

    2012-01-01

    Full Text Available Background. The pulmonary artery catheter (PAC is an accepted clinical method of measuring cardiac output (CO despite no prior validation. The ultrasonic cardiac output monitor (USCOM is a noninvasive alternative to PAC using Doppler ultrasound (CW. We compared PAC and USCOM CO measurements against a gold standard, the aortic flow probe (FP, in sheep at varying outputs. Methods. Ten conscious sheep, with implanted FPs, had measurements of CO by FP, USCOM, and PAC, at rest and during intervention with inotropes and vasopressors. Results. CO measurements by FP, PAC, and USCOM were 4.0±1.2 L/min, 4.8±1.5 L/min, and 4.0±1.4 L/min, respectively, (=280, range 1.9 L/min to 11.7 L/min. Percentage bias and precision between FP and PAC, and FP and USCOM was −17 and 47%, and 1 and 36%, respectively. PAC under-measured Dobutamine-induced CO changes by 20% (relative 66% compared with FP, while USCOM measures varied from FP by 3% (relative 10%. PAC reliably detected −30% but not +40% CO changes, as measured by receiver operating characteristic area under the curve (AUC, while USCOM reliably detected ±5% changes in CO (AUC>0.70. Conclusions. PAC demonstrated poor accuracy and sensitivity as a measure of CO. USCOM provided equivalent measurements to FP across a sixfold range of outputs, reliably detecting ±5% changes.

  1. Impact of extracorporeal blood flow rate on blood pressure, pulse rate and cardiac output during haemodialysis

    DEFF Research Database (Denmark)

    Schytz, Philip Andreas; Mace, Maria Lerche; Soja, Anne Merete Boas

    2015-01-01

    BACKGROUND: If blood pressure (BP) falls during haemodialysis (HD) [intradialytic hypotension (IDH)] a common clinical practice is to reduce the extracorporeal blood flow rate (EBFR). Consequently the efficacy of the HD (Kt/V) is reduced. However, only very limited knowledge on the effect of redu...

  2. Delirium in cardiac surgery : a study on risk-assessment and long-term consequenses

    NARCIS (Netherlands)

    Koster, Sandra

    2011-01-01

    BACKGROUND: Delirium or acute confusion is a temporary mental disorder, which occurs frequently among hospitalized elderly patients. Patients who undergo cardiac surgery have an increased risk of developing delirium. Delirium is associated with many negative consequences. Therefore, prevention or ea

  3. Cardiac MRI assessment of right ventricular function: impact of right bundle branch block on the evaluation of cardiac performance parameters

    Energy Technology Data Exchange (ETDEWEB)

    Marterer, Robert; Tschauner, Sebastian; Sorantin, Erich [Medical University of Graz, Division of Pediatric Radiology, Department of Radiology, Graz (Austria); Zeng, Hongchun [First Affiliated Hospital of Xinjiang Medical University, Department of Ultrasonography, Urumqi (China); Koestenberger, Martin [Medical University of Graz, Division of Pediatric Cardiology, Department of Pediatrics and Adolescent Medicine, Graz (Austria)

    2015-12-15

    Right ventricular (RV) function represents a prognostic marker in patients with corrected congenital heart disease. In up to 80 % of these patients, right branch bundle block (RBBB) exists and leads to asynchronous ventricular contraction. The aim of this retrospective study was to evaluate the change of RV performance parameters considering delayed RV end-systolic contraction. RV volumes of 33 patients were assessed twice: 1) not taking account of RBBB (group I), and 2) considering RBBB (group II). According to the RV ejection fraction (EF) for both groups, RV function was classified in different categories (>50 % = normal, 40-50 % = mildly-, 30-40 % = moderately-, <30 % = severely-reduced). The mean time difference between maximal systolic contraction of the septum and RV free wall was 90.7 ms ± 42.6. Consequently, RV end-systolic volume was significantly decreased in group II (p < 0.001). Accordingly, RV stroke volume and RV EF were significantly higher in group II (p < 0.001). There was also a significant change in the assessment of RV function (p < 0.02). RBBB induced delayed RV contraction can be detected at CMR. Ignoring the RV physiology in RBBB patients leads to a statistically significant underscoring of RV performance parameters. (orig.)

  4. Kinetic assessment of measured mass flow rates and streamwise pressure distributions in microchannel gas flows

    Institute of Scientific and Technical Information of China (English)

    Jing Fan; Chong Xie; Jianzheng Jiang

    2007-01-01

    Measured mass flow rates and streamwise pressure distributions of gas flowing through microchannels were reported by many researchers. Assessment of these data is crucial before they are used in the examination of slip models and numerical schemes, and in the design of microchannel elements in various MEMS devices. On the basis of kinetic solutions of the mass flow rates and pressure distributions in microchannel gas flows, the measured data available are properly normalized and then are compared with each other. The 69 normalized data of measured pressure distributions are in excellent agreement, and 67 of them are within 1 ± 0.05. The normalized data of mass flow-rates ranging between 0.95 and 1 agree well with each other as the inlet Knudsen number Kni > 0.02, but they scat ter between 0.85 and 1.15 as Kni < 0.02 with, to some extent, a very interesting bifurcation trend.

  5. Accounting for environmental flow requirements in global water assessments

    NARCIS (Netherlands)

    Pastor, A.V.; Ludwig, F.; Biemans, H.; Hoff, H.; Kabat, P.

    2014-01-01

    As the water requirement for food production and other human needs grows, quantification of environmental flow requirements (EFRs) is necessary to assess the amount of water needed to sustain freshwater ecosystems. EFRs are the result of the quantification of water necessary to sustain the riverine

  6. Flow cytometric assessment of viability of lactic acid bacteria

    NARCIS (Netherlands)

    Bunthof, C.J.; Bloemen, K.; Breeuwer, P.; Rombouts, F.M.; Abee, T.

    2001-01-01

    The viability of lactic acid bacteria is crucial for their applications as dairy starters and as probiotics. We investigated the usefulness of flow cytometry (FCM) for viability assessment of lactic acid bacteria. The esterase substrate carboxyfluorescein diacetate (cFDA) and the dye exclusion DNA b

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

    Science.gov (United States)

    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

  8. Early assessment of sub-clinical cardiac involvement in systemic sclerosis (SSc) using delayed enhancement cardiac magnetic resonance (CE-MRI)

    Energy Technology Data Exchange (ETDEWEB)

    Di Cesare, Ernesto, E-mail: ernesto.dicesare@cc.univaq.it [Department of Radiology, University of L’Aquila, Via Vetoio 1, 67100 L’Aquila (Italy); Battisti, Sara; Di Sibio, Alessandra [Department of Radiology, University of L’Aquila, Via Vetoio 1, 67100 L’Aquila (Italy); Cipriani, Paola; Giacomelli, Roberto; Liakouli, Vasiliky; Ruscitti, Piero [Rheumatology Clinic, Department of Internal Medicine and Public Health, University of L’Aquila, L’Aquila (Italy); Masciocchi, Carlo [Department of Radiology, University of L’Aquila, Via Vetoio 1, 67100 L’Aquila (Italy)

    2013-06-15

    Objectives: Systemic sclerosis heart involvement (SHI) is one of systemic sclerosis (SSc) most frequent complications, both in diffuse (dcSSc) and limited (lcSSc) cutaneous forms of disease. Nowadays, SHI is a major factor decreasing SSc survival rate because, when clinically evident, is associated with 70% of mortality at 5 years. SHI shows different forms, primary and/or secondary. Primary myocardial SHI is characterized by fibrosis. Aim of our study is to assess the presence and pattern of fibrosis as detected by cardiac magnetic resonance (CMR) in systemic sclerosis. Methods: In this study, we used CE-MRI (contrast enhanced-MRI) in 58 female SSc patients. Images were evaluated to obtain functional parameters and to see presence, location and pattern (nodular, linear or diffuse) of myocardial LE, sign of fibrosis. CE-MRI findings were correlated with patients clinical setting. Results: Myocardial fibrosis was detected in 25 of 58 patients (43%). The main finding observed in 16 of these 25 patients was a late enhancement showing a linear pattern, without coronary distribution and sparing the sub-endocardial myocardial layers. A patchy nodular enhancement pattern was observed in 9 patients (36%). Patients with linear pattern presented dcSSc, on the contrary patients with nodular LE displayed the lcSSc form. Conclusions: This study shows that CE-MRI is a reliable technique to detect SHI earlier than other methods. SHI increase passive myocardial stiffness, proportional to collagen deposition degree, leading to cardiac remodelling with possible development of heart failure, even with normal ejection fraction. An early treatment of SHI might improve SSc patients outcome.

  9. Assessment of low-flow, low-gradient aortic stenosis: multimodality imaging is the key to success.

    Science.gov (United States)

    Clavel, Marie-Annick; Pibarot, Philippe

    2014-09-01

    In patients with aortic stenosis (AS), a low-flow state may occur with reduced LV ejection fraction (LVEF) (i.e., classic low flow) or with preserved LVEF (i.e., paradoxical low flow) and it is often associated with low gradient because the gradient is highly flow-dependent. Low-flow, low-gradient (LF-LG) AS is a frequent clinical entity generally associated with worse outcomes. A multimodality imaging approach, including comprehensive resting echocardiography, dobutamine stress echocardiography (DSE), and multidetector computed tomography (MDCT), is the key to successful management of patients with LF-LG AS, who represent a highly challenging subset from both a diagnostic and a therapeutic standpoint. DSE and quantification of aortic valve calcification by MDCT provide important information that is crucial to differentiate true-severe from pseudo-severe AS and therefore select the most appropriate therapy (i.e., AVR vs. medical). The assessment of LV flow reserve by DSE is useful to stratify the operative risk and guide decision making between surgical and transcatheter AVR. Other imaging biomarkers, such as the global LV longitudinal strain measured during DSE or the amount of myocardial fibrosis assessed by cardiac magnetic resonance imaging, may provide incremental information for risk stratification and therapeutic management in LF-LG AS, but additional studies are needed to validate and refine these emerging biomarkers further.

  10. Integrated imaging of cardiac anatomy, physiology, and viability.

    Science.gov (United States)

    Arrighi, James A

    2009-03-01

    Technologic developments in imaging will have a significant impact on cardiac imaging over the next decade. These advances will permit more detailed assessment of cardiac anatomy, complex assessment of cardiac physiology, and integration of anatomic and physiologic data. The distinction between anatomic and physiologic imaging is important. For assessing patients with known or suspected coronary artery disease, physiologic and anatomic imaging data are complementary. The strength of anatomic imaging rests in its ability to detect the presence of disease, whereas physiologic imaging techniques assess the impact of disease, such as whether a coronary atherosclerotic lesion limits myocardial blood flow. Research indicates that physiologic data are more prognostically important than anatomic data, but both may be important in patient management decisions. Integrated cardiac imaging is an evolving field, with many potential indications. These include assessment of coronary stenosis, myocardial viability, anatomic and physiologic characterization of atherosclerotic plaque, and advanced molecular imaging.

  11. Non-invasive automated assessment of the ratio of pulmonary to systemic flow in patients with atrial septal defects by the colour Doppler velocity profile integration method

    OpenAIRE

    Ueda, Y.; Hozumi, T; Yoshida, K.; Watanabe, H; Akasaka, T; Takagi, T; Yamamuro, A; Homma, S; Yoshikawa, J

    2002-01-01

    Background: The recent introduction of the automated cardiac flow measurement (ACM) method, using spatiotemporal integration of the Doppler velocity profile, provides a quick and accurate automated calculation of cardiac output.

  12. MR assessment of absolute myocardial blood flow and vasodilator flow reserve in patients with hypertrophic cardiomyopathy

    Energy Technology Data Exchange (ETDEWEB)

    Kawada, Nanaka; Sakuma, Hajime; Takeda, Kan; Nakagawa, Tsuyoshi; Yamakado, Tetsu; Nakano, Takeshi [Mie Univ., Tsu (Japan). School of Medicine

    1997-04-01

    Absolute coronary blood flow per myocardial mass and coronary flow reserve for the entire left ventricle were evaluated in normals and in patients with hypertrophic cardiomyopathy (HCM) by using fast cine MR imaging and fast velocity encoded cine (VENC) MR imaging. Nine healthy volunteers and 8 patients with HCM were studied with a 1.5 T imager. Breath-hold cine MR images encompassing the whole left ventricle were acquired on short axis imaging planes in order to evaluate myocardial mass. A fast VENC MR images were obtained to measure blood flow volume in the coronary sinus before and after dipyridamole administration (TR/TE=15/5 ms, FOV=28 x 22 cm, slice thickness=5 mm). Coronary flow reserve was calculated as a ratio of hyperemic to baseline coronary flow volumes. In the baseline state, coronary blood flow per myocardial mass was significantly lower in patients with HCM than in normal myocardium (0.56{+-}0.23 vs. 0.78{+-}0.27 ml/min/g, p<0.05). After dipyridamole administration, coronary blood flow per myocardial mass in patients with HCM increased substantially less than that in healthy subjects (0.99{+-}0.38 vs. 2.22{+-}0.55 ml/min/g, p<0.01), resulting in the significantly decreased coronary flow reserve ratio in HCM in comparison with that in normal myocardium (1.86{+-}0.56 vs. 3.11{+-}1.37, p<0.05). In conclusion, breath-hold velocity encoded cine MR imaging is a noninvasive technique which can provide assessments of altered coronary blood flow volume per myocardial mass and vasodilator flow reserve in patients with HCM. (author)

  13. Assessment for hydrodynamic masses of HANARO flow tubes

    Energy Technology Data Exchange (ETDEWEB)

    Ryu, Jeong Soo; Cho, Yeong Garp; Kim, Doo Kie; Woo, Jong Sug; Park, Jin Ho

    2000-06-01

    The effect of hydrodynamic masses is investigated in dynamic characteristics and seismic response analyses of the submerged HANARO hexagonal flow tubes. Consistent hydrodynamic masses of the surrounding water are evaluated by the prepared program using the finite element method, in which arbitrary cross-sections of submerged structures and boundary conditions of the surrounding fluid can be considered. Also lumped hydrodynamic masses are calculated using simple formula applied to hexagonal flow tubes in the infinite fluid. Modal analyses and seismic response spectrum analyses were performed using hydrodynamic masses obtained by the finite element method and the simple formula. The results of modal analysis were verified by comparing the results measured from modal tests. And the displacement results of the seismic response spectrum analysis were assessed by comparing the consistent and the lumped hydrodynamic masses obtained by various methods. Finally practical criteria based on parametric studies are proposed as the lumped hydrodynamic masses for HANARO flow tubes.

  14. Assessment of Equine Autoimmune Thrombocytopenia (EAT by flow cytometry

    Directory of Open Access Journals (Sweden)

    Schwarzwald Colin

    2001-04-01

    Full Text Available Abstract Rationale Thrombocytopenia is a platelet associated process that occurs in human and animals as result of i decreased production; ii increased utilization; iii increased destruction coupled to the presence of antibodies, within a process know as immune-mediated thrombocytopenia (IMT; or iv platelet sequestration. Thus, the differentiation of the origin of IMT and the development of reliable diagnostic approaches and methodologies are important in the clarification of IMT pathogenesis. Therefore, there is a growing need in the field for easy to perform assays for assessing platelet morphological characteristics paired with detection of platelet-bound IgG. Objectives This study is aimed to develop and characterize a single color flow cytometric assay for detection of platelet-bound IgG in horses, in combination with flow cytometric assessment of platelet morphological characteristics. Findings The FSC and SSC evaluation of the platelets obtained from the thrombocytopenic animals shows several distinctive features in comparison to the flow cytometric profile of platelets from healthy animals. The thrombocytopenic animals displayed i increased number of platelets with high FSC and high SSC, ii a significant number of those gigantic platelets had strong fluorescent signal (IgG bound, iii very small platelets or platelet derived microparticles were found significantly enhanced in one of the thrombocytopenic horses, iv significant numbers of these microplatelet/microparticles/platelet-fragments still carry very high fluorescence. Conclusions This study describes the development and characterization of an easy to perform, inexpensive, and noninvasive single color flow cytometric assay for detection of platelet-bound IgG, in combination with flow cytometric assessment of platelet morphological characteristics in horses.

  15. Study of Transthoracic Impedance Cardiogram for Assessment of Cardiac Hemodynamics in Atrial Fibrillation Patents

    Directory of Open Access Journals (Sweden)

    Vessela Krasteva

    2012-09-01

    Full Text Available This study aims to test the usability of the transthoracic impedance cardiogram (ICG for assessment of the quality of myocardial contractions in atrial fibrillation (AFIB vs. sinus rhythm (SR, using signals recorded via defibrillation pads during external cardioversion (ECV. Data from 88 patients with persistent AFIB who received planned ECV are processed. AFIB is treated with cardioverter/defibrillator DG4000 (Schiller Médical, France using a non-escalating protocol 200J/200J/200J. Successful ECV is defined as restoration of SR for gt 1min. The electrocardiogram (ECG, thoracic baseline impedance (Z and dynamic impedance components dZ, dZ/dt captured via self-adhesive pads in antero- apical position are processed. Heartbeat contractions are evaluated by several measures extracted from the mean ICG patterns during systole: from dZ pattern - ICG (peak amplitude, range, area; from dZ/dt pattern - ICG velocity (peak, range, area and left ventricular ejection time (LVET. The hemodynamical indices measured before and after ECV are: mean heart rate over 2 minutes (HR, standard deviation of HR (HRV, systolic (SysBP and diastolic (DiaBP blood pressure. When the rhythm converts from AFIB to SR (74 patients, all measures on dZ, dZ/dt patterns significantly increase: dZ (64-102%, dZ/dt (31-67%, LVET (18%, p lt 0.05. Significant decrease of HR (-36%, HRV (-53%, SysBP (-11% and DiaBP (-19% are also observed. Unsuccessful ECVs without conversion to SR (14 patients are, however, associated with non-significant increase of dZ (10-21%, dZ/dt (0.3-29%, LVET (9%, p gt 0.05 when comparing pre-shock AFIB vs. post-shock AFIB. No clear change in HR (-9% and HRV (6%, and slight decrease of SysBP (-10% and DiaBP (-8% are observed. The level of improvement of cardiac output quality in post-shock SR vs. pre-shock AFIB as estimated by ICG is related to a set of more than 60 clinical and hemodynamical parameters. Significant correlation coefficients are found to: Beta

  16. In Vitro Study of Influence of Mimic Cardiac Rate on Hydrodynamics of the Different Mechanical Cardiac Valve Prostheses

    Institute of Scientific and Technical Information of China (English)

    CHU Yin-ping; CHENG Jin-lian; CHEN Ru-kun; FAN Yu-bo; PU Fang

    2005-01-01

    Objective:To assess the influence of mimic cardiac rate on hydrodynamics of the different mechanical prosthetic cardiac valves. Methods: US-made CarboMedics bileaflet valve and China-made Jiuling bileaflet valve and C-L tilting disc valve have been tested in a pulsatile flow simulator in the aortic position. The testing condition was set at the mimic cardiac rate of 55 beats/min,75 beats/min,100beats/min and a constant mimic cardiac output of 4L/min. The mean pressure differences (△P) ,leakage volumes (LEV) and closing volumes (CLV) across each valve,and the effective orifice areas(EOA) have been analyzed. Results:Within the range of physiology,the △P,LEV and CLV were falling as the increasing of mimic cardiac rate,and the extent of variance was larger. The EOA was increasing with the increase of the mimic cardiac rate. It is a different response as the altering of the cardiac rate for the different type of the mechanical prosthetic cardiac valves.Conclusions:The change of the mimic cardiac rate can affect the hydrodynamics of the mechanical prosthetic cardiac valves. The hydrodynamics of the bileaflet valve prosthesis is better than the tilting disc valve.

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

    Science.gov (United States)

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

    2015-12-01

    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.

  18. A new method of assessing cardiac autonomic function and its comparison with spectral analysis and coefficient of variation of R-R interval.

    Science.gov (United States)

    Toichi, M; Sugiura, T; Murai, T; Sengoku, A

    1997-01-12

    A new non-linear method of assessing cardiac autonomic function was examined in a pharmacological experiment in ten healthy volunteers. The R-R interval data obtained under a control condition and in autonomic blockade by atropine and by propranolol were analyzed by each of the new methods employing Lorenz plot, spectral analysis and the coefficient of variation. With our method we derived two measures, the cardiac vagal index and the cardiac sympathetic index, which indicate vagal and sympathetic function separately. These two indices were found to be more reliable than those obtained by the other two methods. We anticipate that the non-invasive assessment of short-term cardiac autonomic function will come to be performed more reliably and conveniently by this method.

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

    Energy Technology Data Exchange (ETDEWEB)

    Petriz, João Luiz Fernandes, E-mail: jlpetriz@cardiol.br [Universidade Federal do Rio de Janeiro (UFRJ) / Instituto do Coração Edson Saad - Programa de Pós Graduação em Medicina (Cardiologia), Rio de Janeiro, RJ (Brazil); Hospital Barra D’Or, Rio de Janeiro, RJ (Brazil); Instituto D’Or de Pesquisa e Ensino, Rio de Janeiro, RJ (Brazil); Gomes, Bruno Ferraz de Oliveira; Rua, Braulio Santos [Hospital Barra D’Or, Rio de Janeiro, RJ (Brazil); Azevedo, Clério Francisco [Instituto D’Or de Pesquisa e Ensino, Rio de Janeiro, RJ (Brazil); Hadlich, Marcelo Souza [Universidade Federal do Rio de Janeiro (UFRJ) / Instituto do Coração Edson Saad - Programa de Pós Graduação em Medicina (Cardiologia), Rio de Janeiro, RJ (Brazil); Instituto D’Or de Pesquisa e Ensino, Rio de Janeiro, RJ (Brazil); Mussi, Henrique Thadeu Periard [Universidade Federal do Rio de Janeiro (UFRJ) / Instituto do Coração Edson Saad - Programa de Pós Graduação em Medicina (Cardiologia), Rio de Janeiro, RJ (Brazil); Hospital Barra D’Or, Rio de Janeiro, RJ (Brazil); Taets, Gunnar de Cunto [Instituto D’Or de Pesquisa e Ensino, Rio de Janeiro, RJ (Brazil); Nascimento, Emília Matos do; Pereira, Basílio de Bragança; Silva, Nelson Albuquerque de Souza e [Universidade Federal do Rio de Janeiro (UFRJ) / Instituto do Coração Edson Saad - Programa de Pós Graduação em Medicina (Cardiologia), Rio de Janeiro, RJ (Brazil)

    2015-02-15

    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. 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. 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. 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). 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.

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

    Directory of Open Access Journals (Sweden)

    João Luiz Fernandes Petriz

    2015-02-01

    Full Text Available 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

  1. Advanced neutron source reactor probabilistic flow blockage assessment

    Energy Technology Data Exchange (ETDEWEB)

    Ramsey, C.T.

    1995-08-01

    The Phase I Level I Probabilistic Risk Assessment (PRA) of the conceptual design of the Advanced Neutron Source (ANS) Reactor identified core flow blockage as the most likely internal event leading to fuel damage. The flow blockage event frequency used in the original ANS PRA was based primarily on the flow blockage work done for the High Flux Isotope Reactor (HFIR) PRA. This report examines potential flow blockage scenarios and calculates an estimate of the likelihood of debris-induced fuel damage. The bulk of the report is based specifically on the conceptual design of ANS with a 93%-enriched, two-element core; insights to the impact of the proposed three-element core are examined in Sect. 5. In addition to providing a probability (uncertainty) distribution for the likelihood of core flow blockage, this ongoing effort will serve to indicate potential areas of concern to be focused on in the preliminary design for elimination or mitigation. It will also serve as a loose-parts management tool.

  2. ASSESSMENT OF PLASTIC FLOWS AND STOCKS IN SERBIA USING MATERIAL FLOW ANALYSIS

    Directory of Open Access Journals (Sweden)

    Goran Vujić

    2010-01-01

    Full Text Available Material flow analysis (MFA was used to assess the amounts of plastic materials flows and stocks that are annually produced, consumed, imported, exported, collected, recycled, and disposed in the landfills in Serbia. The analysis revealed that approximatelly 269,000 tons of plastic materials are directly disposed in uncontrolled landfills in Serbia without any preatretment, and that siginificant amounts of these materials have already accumulated in the landfills. The substantial amounts of landfilled plastics represent not only a loss of valuable recourses, but also pose a seriuos treath to the environment and human health, and if the trend of direct plastic landfilling is continued, Serbia will face with grave consecequnces.

  3. Effects of short-term carvedilol on the cardiac sympathetic activity assessed by {sup 123}I-MIBG scintigraphy

    Energy Technology Data Exchange (ETDEWEB)

    Miranda, Sandra Marina Ribeiro de; Mesquita, Evandro Tinoco; Freire, Fabiano de Lima; Ribeiro, Mario Luiz; Nobrega, Antonio Claudio Lucas da; Mesquita, Claudio Tinoco, E-mail: sandramarina@cardiol.b [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil); Azevedo, Jader Cunha; Barbirato, Gustavo Borges; Coimbra, Alexandro [Hospital Pro-Cardiaco, Rio de Janeiro, RJ (Brazil); Dohmann, Hans Fernando da Rocha [Centro de Ensino e Pesquisa do Pro-Cardiaco (PROCEP), Rio de Janeiro, RJ (Brazil)

    2010-03-15

    Background: autonomic alterations in heart failure are associated with an increase in morbimortality. Several noninvasive methods have been employed to evaluate the sympathetic function, including the Meta-Iodobenzylguanidine ({sup 123}I-MIBG) scintigraphy imaging of the heart. Objective: to evaluate the cardiac sympathetic activity through {sup 123}I-MIBG scintigraphy, before and after three months of carvedilol therapy in patients with heart failure and left ventricular ejection fraction (LVEF) < 45%. Patients and methods: sixteen patients, aged 56.3 +- 12.6 years (11 males), with a mean LVEF of 28% +- 8% and no previous use of beta-blockers were recruited for the study. Images of the heart innervation were acquired with {sup 123}I-MIBG, and the serum levels of catecholamines (epinephrine, dopamine and norepinephrine) were measured; the radioisotope ventriculography (RIV) was performed before and after a three-month therapy with carvedilol. Results: patients' functional class showed improvement: before the treatment, 50% of the patients were FC II and 50% were FC III. After 3 months, 7 patients were FC I (43.8%) and 9 were FC II (56.2%), (rho = 0.0001). The mean LVEF assessed by RIV increased from 29% to 33% (rho = 0.017). There was no significant variation in cardiac adrenergic activity assessed by {sup 123}I-MIBG (early and late resting images and washout rate). No significant variation was observed regarding the measurement of catecholamines. Conclusion: the short-term treatment with carvedilol promoted the clinical and LVEF improvement. However, this was not associated to an improvement in the cardiac adrenergic activity, assessed by {sup 123}I-MIBG scintigraphy, as well as the measurement of circulating catecholamines. (author)

  4. Assessment of cardiac stroke volume in patients with implanted cardiac pacemaker using parametric electrical impedance tomography: a theoretical 2D study.

    Science.gov (United States)

    Mhajna, Muhammad; Abboud, Shimon

    2013-05-01

    The present theoretical study examines the ability to estimate cardiac stroke volume (CSV) in patients with implanted cardiac pacemaker using parametric electrical impedance tomography (pEIT) in a 2D computerized model of the thorax. CSV is a direct indicator of the cardiac pumping efficiency. The commonly used methods for measuring CSV require the invasive procedure of right heart catheterization or use expensive imaging techniques (i.e., MRI). Hence, experience with these techniques for diagnosis and monitoring has been limited to hospitalized patients. In the present study, pEIT scheme was applied in a computerized 2D model of the human thorax with implanted cardiac device to determine the left ventricular (LV) volume at different cardiac cycle phases. The LV was simulated as a prolate ellipse with its axes' lengths as the reconstruction parameters while all other geometries and conductivity values remained constant. An optimization was carried out in order to ensure that the ellipse is the appropriate model for the LV at each cardiac cycle phase. LV volumes calculated by both the pEIT algorithm and the ellipsoid model are consistent. A high correlation (ρ = 0.99) between the true and reconstructed volumes was found. The SV calculation error was ∼1%. The results suggest that the LV volume can be estimated using the pEIT method in a 2D computerized model, and that the method has the potential to be used for monitoring patients with implanted cardiac pacemaker.

  5. Assessment of the quality of existing patient educational tools focused on sudden cardiac arrest: a systematic evaluation by the Sudden Cardiac Arrest Thought Leadership Alliance

    Directory of Open Access Journals (Sweden)

    Hazelton G

    2013-04-01

    Full Text Available Garrett Hazelton,1 Sana M Al-Khatib,2,3 Gregg C Fonarow,4 Kevin L Thomas,3 David Hayes,5 Gillian D Sanders,2,3 Susan M Campbell,6 Clyde Yancy,7 Eric D Peterson,2,3 Samuel Sears8 1Department of Psychiatric Medicine, East Carolina University, Greenville, NC, 2Duke Clinical Research Institute, 3Department of Medicine, Duke University School of Medicine, Durham, NC, 4Division of Cardiology, Geffen School of Medicine at UCLA, Los Angeles, CA, 5Mayo Clinic, Rochester, MN, 6WomenHeart, The National Coalition for Women with Heart Disease, Washington, DC, 7Division of Cardiology, Feinburg School of Medicine, Northwestern University, Chicago, IL, 8Departments of Psychology and Cardiology, East Carolina University, Greenville, NC, USA Background: Conveying contemporary treatment options for those at risk of sudden cardiac arrest (SCA is challenging. The purpose of the present research was to evaluate the quality and usability of available patient educational tools relevant to SCA and its treatment options, such as implantable cardioverter defibrillators (ICDs. We hypothesized that this review would identify gaps in areas of information for the enhancement of patient education and decision-making materials. Methods: We used a formal instrument to assess specific domains of content, development, and effectiveness of 18 available SCA and ICD educational tools. The multidisciplinary review panel included two electrophysiologists, two general cardiologists, a cardiac psychologist, a health services researcher, and a patient advocate. Results: Of the 18 education tools, four were rated as “good, may need revisions, but sufficient for use”, 12 were rated as “marginal, needs revision prior to use”, and two were rated as “poor, inadequate for use”. None of the tools were rated as being of “very good” or “excellent” quality. Conclusion: There appear to be opportunities to improve the quality and completeness of existing educational tools for

  6. Quantitative assessment of left ventricular function with dual-source CT in comparison to cardiac magnetic resonance imaging: initial findings

    Energy Technology Data Exchange (ETDEWEB)

    Busch, S.; Johnson, T.R.C.; Wintersperger, B.J.; Minaifar, N.; Bhargava, A.; Rist, C.; Reiser, M.F.; Becker, C.; Nikolaou, K. [University of Munich, Department of Clinical Radiology, Munich (Germany)

    2008-03-15

    Cardiac magnetic resonance imaging and echocardiography are currently regarded as standard modalities for the quantification of left ventricular volumes and ejection fraction. With the recent introduction of dual-source computedtomography (DSCT), the increased temporal resolution of 83 ms should also improve the assessment of cardiac function in CT. The aim of this study was to evaluate the accuracy of DSCT in the assessment of left ventricular functional parameters with cardiac magnetic resonance imaging (MRI) as standard of reference. Fifteen patients (two female, 13 male; mean age 50.8 {+-} 19.2 years) underwent CT and MRI examinations on a DSCT (Somatom Definition; Siemens Medical Solutions, Forchheim, Germany) and a 3.0-Tesla MR scanner (Magnetom Trio; Siemens Medical Solutions), respectively. Multiphase axial CT images were analysed with a semiautomatic region growing algorithms (Syngo Circulation; Siemens Medical Solutions) by two independent blinded observers. In MRI, dynamic cine loops of short axis slices were evaluated with semiautomatic contour detection software (ARGUS; Siemens Medical Solutions) independently by two readers. End-systolic volume (ESV), end-diastolic volume (EDV), ejection fraction (EF) and stroke volume (SV) were determined for both modalities, and correlation coefficient, systematic error, limits of agreement and inter-observer variability were assessed. In DSCT, EDV and ESV were 135.8 {+-} 41.9 ml and 54.9 {+-} 29.6 ml, respectively, compared with 132.1 {+-} 40.8 ml EDV and 57.6 {+-} 27.3 ml ESV in MRI. Thus, EDV was overestimated by 3.7 ml (limits of agreement -46.1/+53.6), while ESV was underestimated by 2.6 ml (-36.6/+31.4). Mean EF was 61.6 {+-} 12.4% in DSCT and 57.9 {+-} 9.0% in MRI, resulting in an overestimation of EF by 3.8% with limits of agreement at -14.7 and +22.2%. Rank correlation rho values were 0.81 for EDV (P = 0.0024), 0.79 for ESV (P = 0.0031) and 0.64 for EF (P = 0.0168). The kappa value of inter

  7. Noninvasive assessment of cardiac output from arterial pressure profiles during exercise.

    Science.gov (United States)

    Antonutto, G; Girardis, M; Tuniz, D; di Prampero, P E

    1995-01-01

    The stroke volume of the left ventricle (SV) was assessed in nine young men (mean age 22.2, ranging from 20 to 25 years) during cycle ergometer upright exercise at exercise intensities from 60 to 150 W (about 20% to 80% of individual maximal aerobic power). The SV was calculated from noninvasive tracings of the arterial blood pressure, determined from photoplethysmograph records and compared to the SV determined simultaneously by pulsed Doppler echocardiography (PDE). Given the relationship SV = As.Z-1 in which A(s) is the area underneath the systolic pressure profile (in millimetres of mercury and second), and Z (in millimetres of mercury and second per millilitre) is the apparent hydraulic impedance of the circulatory system, a prerequisite for the assessment of SV from the photoplethysmograph tracings is a knowledge of Z. The experimental value of Z (hereafter defined Z*) was calculated by dividing A(s) (from the finger photoplethysmograph) by SV as obtained by PDE. When the whole group of subjects was considered, Z* was not greatly affected by the exercise intensity: it amounted to 0.089 (SD 0.028; n = 36). The Z was also estimated independently of any parameter other than heart rate (HR), mean (MAP) and pulse (PP) arterial blood pressure obtained from the photoplethysmograph. A computerized statistical method allowed us to interpolate the experimental values of Z*, HR, PP and MAP by the equation Zm = a.(b + c.HR + d.PP + e.MAP)-1, thus obtaining the coefficients a to e. The mean percentage error between Zm (calculated from the coefficients obtained and Z* was 21.8 (SD 14.3)%. However, it was observed that, in a given subject, Z* was significantly affected by the exercise intensity. Therefore, to improve the estimate of Z a second algorithm was developed to update the experimental value of Z determined initially at rest (Zin). This updated value (Zcor) of Z was calculated as Zcor = Zin. [(f/(i + g.(HR/HRin) + h.(PP/PPin) + 1.(MAP/MAPin)], where HRin, PPin

  8. Assessing preferential flow by simultaneously injecting nanoparticle and chemical tracers

    KAUST Repository

    Subramanian, S. K.

    2013-01-01

    The exact manner in which preferential (e.g., much faster than average) flow occurs in the subsurface through small fractures or permeable connected pathways of other kinds is important to many processes but is difficult to determine, because most chemical tracers diffuse quickly enough from small flow channels that they appear to move more uniformly through the rock than they actually do. We show how preferential flow can be assessed by injecting 2 to 5 nm carbon particles (C-Dots) and an inert KBr chemical tracer at different flow rates into a permeable core channel that is surrounded by a less permeable matrix in laboratory apparatus of three different designs. When the KBr tracer has a long enough transit through the system to diffuse into the matrix, but the C-Dot tracer does not, the C-Dot tracer arrives first and the KBr tracer later, and the separation measures the degree of preferential flow. Tracer sequestration in the matrix can be estimated with a Peclet number, and this is useful for experiment design. A model is used to determine the best fitting core and matrix dispersion parameters and refine estimates of the core and matrix porosities. Almost the same parameter values explain all experiments. The methods demonstrated in the laboratory can be applied to field tests. If nanoparticles can be designed that do not stick while flowing through the subsurface, the methods presented here could be used to determine the degree of fracture control in natural environments, and this capability would have very wide ranging value and applicability.

  9. Cardiac output assessment using oxygen consumption estimated from the left ventricular pressure-volume area.

    Science.gov (United States)

    Negroni, Jorge A; Lascano, Elena C; Bertolotti, Alejandro M; Gómez, Carmen B; Rodríguez Correa, Carlos A; Favaloro, Roberto R

    2010-01-01

    Use of a majority of structural variables (age, sex, height) to estimate oxygen consumption in the calculation of cardiac output (CO) by the Fick principle does not account for changes in physiological conditions. To improve this limitation, oxygen consumption was estimated based on the left ventricular pressure-volume area. A pilot study with 10 patients undergoing right cardiac catheterization showed that this approach was successful to estimate CO (r=0,73, vs. thermodilution measured CO). Further essays changing end-diastolic-volume in the pressure-volume area formula by body weight or body surface area showed that this last yielded the best correlation with the thermodilution measured CO (slope=1, ordinate =0.01 and r=0.93). These preliminary results indicate that use of a formula originated from the pressure-volume-area concept is a good alternative to estimate oxygen consumption for CO calculation.

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

    Science.gov (United States)

    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.

  11. Novel biomarkers for cardiac surgery-associated acute kidney injury: a skeptical assessment of their role.

    Science.gov (United States)

    Sidebotham, David

    2012-12-01

    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.

  12. Cardiopulmonary response to exercise and cardiac assessment in patients with turner syndrome.

    Science.gov (United States)

    Tancredi, Giancarlo; Versacci, Paolo; Pasquino, Anna Maria; Vittucci, Anna Chiara; Pucarelli, Ida; Cappa, Marco; Di Mambro, Corrado; Marino, Bruno

    2011-04-01

    Turner syndrome (TS) is a chromosomal disorder; however, little is known about the exercise tolerance of patients with this syndrome. The aim of the present study was to measure the maximal aerobic capacity and cardiac function using cardiopulmonary exercise testing and lung function tests and to evaluate the cardiac parameters using echocardiography in patients with TS and control subjects. A total of 50 women with TS (mean age 21.3 ± 8.5 years) and 56 age-matched controls (mean age 21.1 ± 3.7 years) were enrolled from the Pediatric Department of "Sapienza" University of Rome and underwent cardiopulmonary exercise testing, lung function testing, and echocardiography. The maximal oxygen uptake was lower in the patients with TS than in the controls (28.4 ± 4.0 vs 35.6 ± 6.2 ml/min/kg; p <0.0001). Also, the forced expiratory volume in 1 second, expressed as a percentage of the predicted value, was greater in the patients with TS than in the controls (116.2 ± 15.2% vs 102.8 ± 4.8%, p <0.0001). The patients with TS had a smaller left ventricle than did the controls. Tissue Doppler imaging revealed subclinical systolic and diastolic dysfunction in the left ventricle in those with TS but not in the controls. The left ventricular mass index was greater in the patients with TS than in the controls (38.6 ± 9.3 vs 27.2 ± 4.5 g/m(2.7), p <0.0001). In conclusion, the patients with TS had a lower maximal aerobic capacity and exercise tolerance than did the controls. The anatomic and functional cardiac aspects were peculiar to those with TS and might represent a specific cardiac phenotype.

  13. Preliminary Assessment of the Loss of Flow Accident for PGSFR

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Andong; Choi, Yong Won; Bae, Moohoon [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

    2014-10-15

    TRACE code have being considered as a candidate tool for SFR audit calculation for licensing review since 2012. On the basis of modeling and precalculation experience for the Demonstration Sodium cooled Fast Reactor (DSFR-600), TRACE code model for PGSFR was developed this year. In this paper, one of representing Design Base Event (DBE), Loss of Flow (LOF) accident was pre-calculated and Locked Rotor (LR) case was compared with LOF case since it could be a possible limiting case for LOF representing DBE. Sensitivity calculation for the LR case was implemented for identifying major parameters for the scenario. For the preparation of the review of licensing application for PGSFR, TRACE model for the PGSFR was developed and the loss of flow accident was precalculated. The locked pump rotor case was also calculated as a possible bounding case for the loss of flow scenario. Pre-calculation showed that the locked rotor case was similar or worst case to the loss of flow accident. Therefore, the locked rotor case should take into account in design base accident assessment of PGSFR. Sensitivity calculations for the rocked rotor case also studied for identification of unfixed design parameters influencing to estimation of inner surface temperature. Sensitivity result showed that the first temperature peak was largely influenced by reactor trip delay and second peak mostly influenced by pump coast down characteristic.

  14. Effects of DL-homocysteine thiolactone on cardiac contractility, coronary flow, and oxidative stress markers in the isolated rat heart: the role of different gasotransmitters.

    Science.gov (United States)

    Zivkovic, Vladimir; Jakovljevic, Vladimir; Pechanova, Olga; Srejovic, Ivan; Joksimovic, Jovana; Selakovic, Dragica; Barudzic, Nevena; Djuric, Dragan M

    2013-01-01

    Considering the adverse effects of DL-homocysteine thiolactone hydrochloride (DL-Hcy TLHC) on vascular function and the possible role of oxidative stress in these mechanisms, the aim of this study was to assess the influence of DL-Hcy TLHC alone and in combination with specific inhibitors of important gasotransmitters, such as L-NAME, DL-PAG, and PPR IX, on cardiac contractility, coronary flow, and oxidative stress markers in an isolated rat heart. The hearts were retrogradely perfused according to the Langendorff technique at a 70 cm H2O and administered 10  μM DL-Hcy TLHC alone or in combination with 30  μM L-NAME, 10  μM DL-PAG, or 10  μM PPR IX. The following parameters were measured: dp/dt max, dp/dt min, SLVP, DLVP, MBP, HR, and CF. Oxidative stress markers were measured spectrophotometrically in coronary effluent through TBARS, NO2, O2(-), and H2O2 concentrations. The administration of DL-Hcy TLHC alone decreased dp/dt max, SLVP, and CF but did not change any oxidative stress parameters. DL-Hcy TLHC with L-NAME decreased CF, O2(-), H2O2, and TBARS. The administration of DL-Hcy TLHC with DL-PAG significantly increased dp/dt max but decreased DLVP, CF, and TBARS. Administration of DL-Hcy TLHC with PPR IX caused a decrease in dp/dt max, SLVP, HR, CF, and TBARS.

  15. Effects of DL-Homocysteine Thiolactone on Cardiac Contractility, Coronary Flow, and Oxidative Stress Markers in the Isolated Rat Heart: The Role of Different Gasotransmitters

    Directory of Open Access Journals (Sweden)

    Vladimir Zivkovic

    2013-01-01

    Full Text Available Considering the adverse effects of DL-homocysteine thiolactone hydrochloride (DL-Hcy TLHC on vascular function and the possible role of oxidative stress in these mechanisms, the aim of this study was to assess the influence of DL-Hcy TLHC alone and in combination with specific inhibitors of important gasotransmitters, such as L-NAME, DL-PAG, and PPR IX, on cardiac contractility, coronary flow, and oxidative stress markers in an isolated rat heart. The hearts were retrogradely perfused according to the Langendorff technique at a 70 cm H2O and administered 10 μM DL-Hcy TLHC alone or in combination with 30 μM L-NAME, 10 μM DL-PAG, or 10 μM PPR IX. The following parameters were measured: dp/dt max, dp/dt min, SLVP, DLVP, MBP, HR, and CF. Oxidative stress markers were measured spectrophotometrically in coronary effluent through TBARS, NO2, O2-, and H2O2 concentrations. The administration of DL-Hcy TLHC alone decreased dp/dt max, SLVP, and CF but did not change any oxidative stress parameters. DL-Hcy TLHC with L-NAME decreased CF, O2-, H2O2, and TBARS. The administration of DL-Hcy TLHC with DL-PAG significantly increased dp/dt max but decreased DLVP, CF, and TBARS. Administration of DL-Hcy TLHC with PPR IX caused a decrease in dp/dt max, SLVP, HR, CF, and TBARS.

  16. Assessment of mathematical models for the flow in directional solidification

    Science.gov (United States)

    Lu, Jay W.; Chen, Falin

    1997-02-01

    In a binary solution unidirectionally solidified from below, the bulk melt and the eutectic solid is separated by a dendritic mushy zone. The mathematical formulation governing the fluid motion shall thus consist of the equations in the bulk melt and the mushy zone and the associated boundary conditions. In the bulk melt, assuming that the melt is a Newtonian fluid, the governing equations are the continuity equation, the Navier-Stokes equations, the heat conservation equation, and the solute conservation equation. In the mushy layer, however, the formulation of the momentum equation and the associated boundary conditions are diversified in previous investigations. In this paper, we discuss three mathematical models, which had been previously applied to study the flow induced by the solidification of binary solutions cooling from below. The assessment is given on the bases of the stability characteristics of the convective flow and the comparison between the numerical and experimental results.

  17. Limitations of early serum creatinine variations for the assessment of kidney injury in neonates and infants with cardiac surgery.

    Directory of Open Access Journals (Sweden)

    Mirela Bojan

    Full Text Available BACKGROUND: Changes in kidney function, as assessed by early and even small variations in serum creatinine (ΔsCr, affect survival in adults following cardiac surgery but such associations have not been reported in infants. This raises the question of the adequate assessment of kidney function by early ΔsCr in infants undergoing cardiac surgery. METHODOLOGY: The ability of ΔsCr within 2 days of surgery to assess the severity of kidney injury, accounted for by the risk of 30-day mortality, was explored retrospectively in 1019 consecutive neonates and infants. Patients aged ≤ 10 days were analyzed separately because of the physiological improvement in glomerular filtration early after birth. The Kml algorithm, an implementation of k-means for longitudinal data, was used to describe creatinine kinetics, and the receiver operating characteristic and the reclassification methodology to assess discrimination and the predictive ability of the risk of death. RESULTS: Three clusters of ΔsCr were identified: in 50% of all patients creatinine decreased, in 41.4% it increased slightly, and in 8.6% it rose abruptly. Mortality rates were not significantly different between the first and second clusters, 1.6% [0.0-4.1] vs 5.9% [1.9-10.9], respectively, in patients aged ≤ 10 days, and 1.6% [0.5-3.0] vs 3.8% [1.9-6.0] in older ones. Mortality rates were significantly higher when creatinine rose abruptly, 30.3% [15.1-46.2] in patients aged ≤ 10 days, and 15.1% [5.9-25.5] in older ones. However, only 41.3% of all patients who died had an abrupt increase in creatinine. ΔsCr improved prediction in survivors, but not in patients who died, and did not improve discrimination over a clinical mortality model. CONCLUSIONS: The present results suggest that a postoperative decrease in creatinine represents the normal course in neonates and infants with cardiac surgery, and that early creatinine variations lack sensitivity for the assessment of the severity of

  18. ASSESSMENT OF DIASTOLIC FUNCTION BY COMBINED TRNSMITRAL AND PULMONARY VENOUS FLOW VELOCITY CURVES

    Directory of Open Access Journals (Sweden)

    Nagabhushana

    2014-04-01

    Full Text Available BACKGROUND: Several clinical studies have reported that 30% to 50% of patients with congestive heart failure have preserved left ventricular systolic function and isolated diastolic dysfunction. Detection of diastolic dysfunction is important factor in cardiac evaluation of hypertensives. MATERIAL AND METHODS: retrospective study carried out in Medicine department, SIMS, Shimoga for one year from Jan 2013 to Jan 2014. 50 patients who are hypertensive without any abnormality were studied general and systemic examination done, 2d echocardiography done in which transmitral flow velocity (E/A and pulmonary venous A duration- mitral A duration (∆d is measured. RESULT: 32% of subjects were newly diagnosed hypertensives in our study. 56% of cases had normal diastolic function as defined by E/A ratio (>1, 18% of cases in our study with normal E/A ratio were found to have pseudonormal pattern of diastolic function. LVDD of 62% is found in this study. CONCLUSION: The abnormal diastolic function as assessed by abnormal E/A ratio was seen in 44% of cases. Abnormal ∆d was found in 18% of cases out of 56% who had normal E/A ratio. These cases are said to have ‘pseudonormal’ pattern of diastolic function. The current study demonstrated that the presence of LV diastolic dysfunction in hypertensive patients is actually greater than previously reported by studies that analyzed transmitral flow velocity curves alone. To avoid overlooking patients with diastolic dysfunction, the combined analysis of transmitral and pulmonary venous flow velocity curves is recommended.

  19. Role of Nuclear Medicine in the cardiac resinchronization therapy

    Energy Technology Data Exchange (ETDEWEB)

    Brandao, Simone Cristina Soares, E-mail: simonecordis@yahoo.com.br [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil); Giorgi, Maria Clementina Pinto; D' Orio, Silvana Angelina; Meneghetti, Jose Claudio [Instituto do Coracao (InCor/FM/USP), Sao Paulo, SP (Brazil)

    2011-10-15

    Cardiac resynchronization therapy (CRT) emerged as one of the most promising approaches in the treatment of cardiac dyssynchrony in heart failure patients' refractory to medical treatment. However, despite very promising clinical and functional results, individual response analyses show that a significant number of patients do not respond to treatment. The role of nuclear medicine and molecular imaging in the selection of CRT candidates by the assessment of cardiac dyssynchrony, myocardial viability, myocardial perfusion and blood flow and sympathetic cardiac activity has been discussed in this review. The potential utilization of this tool to improve the comprehension of detrimental effects of dyssynchrony on cardiac function and the evaluation and monitoring of the response to CRT were also considered. Other molecular targets that characterize glucose and fatty acid metabolism, apoptosis, angiotensin converting enzyme activity and angiogenesis that can be evaluated with this technique were described. (author)

  20. Detailed free span assessment for Mexilhao flow lines

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Antonio; Franco, Luciano; Eigbe, Uwa; BomfimSilva, Carlos [INTECSEA, Houston, TX (United States); Escudero, Carlos [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil)

    2009-07-01

    The subsea gas production system of Mexilhao Field SPS-35, Santos Basin, offshore Brazil, is composed basically of two rigid 12.75 inches production flow lines approximately 21 km long installed in a fairly rough seabed. During the basic design, the free span assessment was performed considering the maximum allowable free span length determined by the response model proposed by DNV-RP-F105. This approach resulted in a large number of predicted free span requiring corrections, leading to a higher capital cost for the project. In this sense, a detailed free span VIV fatigue assessment was proposed, considering multi-spans and multi-mode effects and also the post lay survey data. The assessment followed the DNV-RP-F105 recommendations for multi-spans and multi-mode effects, using Finite Element Analysis to determine the natural frequencies, mode shapes and corresponding stresses associated with the mode shapes. The assessment was performed in three stages, the first during the detailed design as part of the bottom roughness analysis using the expected residual pipelay tension. The second stage was performed after pipelay, considering the post-lay survey data, where the actual requirements for span correction were determined. Actual pipelay tension was used and seabed soil stiffness adjusted in the model to match the as-laid pipeline profile obtained from the survey data. The first and second stage assessments are seamlessly automated to speed up the evaluation process and allow for quick response in the field, which was important to keep the construction vessel time minimized. The third stage was performed once the corrections of the spans were made and the purpose was to confirm that the new pipeline configuration along the supported spans had sufficient fatigue life for the temporary and operational phases. For the assessment of all three stages, the probability of occurrence and directionality of the near bottom current was considered to improve prediction of the

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

    Science.gov (United States)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  3. Transcutaneous Vagus Nerve Stimulation: Retrospective Assessment of Cardiac Safety in a Pilot Study

    OpenAIRE

    Peter Michael Kreuzer; Michael eLandgrebe; Oliver eHusser; Markus eResch; Martin eSchecklmann; Florian eGeisreiter; Poeppl, Timm B.; Sarah Julia Prasser; Goeran eHajak; Berthold eLangguth

    2012-01-01

    Abstract BACKGROUND: Vagus nerve stimulation has been successfully used as a treatment strategy for epilepsy and affective disorders for years. Transcutaneous vagus nerve stimulation (tVNS) is a new non-invasive method to stimulate the vagus nerve, which has been shown to modulate neuronal activity in distinct brain areas. OBJECTIVES: Here we report effects of tVNS on cardiac function from a pilot study, which was conducted to evaluate the feasibility and safety of tVNS for the treatment of c...

  4. Differentiation of myocardial ischemia and infarction assessed by dynamic computed tomography perfusion imaging and comparison with cardiac magnetic resonance and single-photon emission computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Tanabe, Yuki; Kido, Teruhito; Kurata, Akira; Miyagawa, Masao; Mochizuki, Teruhito [Ehime University Graduate School of Medicine, Department of Radiology, Toon, Ehime (Japan); Uetani, Teruyoshi; Kono, Tamami; Ogimoto, Akiyoshi [Ehime University Graduate School of Medicine, Department of Cardiology, Pulmonology, Hypertension and Nephrology, Toon, Ehime (Japan); Soma, Tsutomu [FUJIFILM RI Pharma Co., Ltd., QMS Group, Quality Assurance Department, Tokyo (Japan); Graduate School of Medicine, University of Tokyo, Department of Radiology, Tokyo (Japan); Murase, Kenya [Osaka University Graduate School of Medicine, Department of Medical Physics and Engineering, Division of Medical Technology and Science, Faculty of Health Science, Osaka (Japan); Iwaki, Hirotaka [Ehime University Graduate School of Medicine, Center for Clinical Research Data and Biostatistics, Toon, Ehime (Japan)

    2016-11-15

    To evaluate the feasibility of myocardial blood flow (MBF) by computed tomography from dynamic CT perfusion (CTP) for detecting myocardial ischemia and infarction assessed by cardiac magnetic resonance (CMR) or single-photon emission computed tomography (SPECT). Fifty-three patients who underwent stress dynamic CTP and either SPECT (n = 25) or CMR (n = 28) were retrospectively selected. Normal and abnormal perfused myocardium (ischemia/infarction) were assessed by SPECT/CMR using 16-segment model. Sensitivity and specificity of CT-MBF (mL/g/min) for detecting the ischemic/infarction and severe infarction were assessed. The abnormal perfused myocardium and severe infarction were seen in SPECT (n = 90 and n = 19 of 400 segments) and CMR (n = 223 and n = 36 of 448 segments). For detecting the abnormal perfused myocardium, sensitivity and specificity were 80 % (95 %CI, 71-90) and 86 % (95 %CI, 76-91) in SPECT (cut-off MBF, 1.23), and 82 % (95 %CI, 76-88) and 87 % (95 %CI, 80-92) in CMR (cut-off MBF, 1.25). For detecting severe infarction, sensitivity and specificity were 95 % (95 %CI, 52-100) and 72 % (95 %CI, 53-91) in SPECT (cut-off MBF, 0.92), and 78 % (95 %CI, 67-97) and 80 % (95 %CI, 58-86) in CMR (cut-off MBF, 0.98), respectively. Dynamic CTP has a potential to detect abnormal perfused myocardium and severe infarction assessed by SPECT/CMR using comparable cut-off MBF. (orig.)

  5. Water shortage risk assessment using spatiotemporal flow simulation

    Science.gov (United States)

    Hsieh, Hsin-I.; Su, Ming-Daw; Wu, Yii-Chen; Cheng, Ke-Sheng

    2016-12-01

    Paddy irrigation practices in Taiwan utilize complicated water conveyance networks which draw streamflows from different tributaries. Characterizing and simulating streamflow series is thus an essential task for irrigation risk assessment and planning mitigation measures. It generally involves modeling the temporal variation and spatial correlation of streamflow data at different sites. Like many other environmental variables, streamflows are asymmetric and non-Gaussian. Such properties exacerbate the difficulties in spatiotemporal modeling of streamflow data. A stochastic spatiotemporal simulation approach capable of generating non-Gaussian ten-day period streamflow data series at different sites is presented in this paper. Historical flow data from different flow stations in southern Taiwan were used to exemplify the application of the proposed model. Simulated realizations of the spatiotemporal anisotropic multivariate Pearson type III distribution were validated by comparing parameters and spatiotemporal correlation characteristics of the simulated data and the observed streamflow data. Risks of irrigation water shortage were estimated and the effect of mitigation measures was assessed using the simulated data.

  6. Assessing computer waste generation in Chile using material flow analysis.

    Science.gov (United States)

    Steubing, Bernhard; Böni, Heinz; Schluep, Mathias; Silva, Uca; Ludwig, Christian

    2010-03-01

    The quantities of e-waste are expected to increase sharply in Chile. The purpose of this paper is to provide a quantitative data basis on generated e-waste quantities. A material flow analysis was carried out assessing the generation of e-waste from computer equipment (desktop and laptop PCs as well as CRT and LCD-monitors). Import and sales data were collected from the Chilean Customs database as well as from publications by the International Data Corporation. A survey was conducted to determine consumers' choices with respect to storage, re-use and disposal of computer equipment. The generation of e-waste was assessed in a baseline as well as upper and lower scenarios until 2020. The results for the baseline scenario show that about 10,000 and 20,000 tons of computer waste may be generated in the years 2010 and 2020, respectively. The cumulative e-waste generation will be four to five times higher in the upcoming decade (2010-2019) than during the current decade (2000-2009). By 2020, the shares of LCD-monitors and laptops will increase more rapidly replacing other e-waste including the CRT-monitors. The model also shows the principal flows of computer equipment from production and sale to recycling and disposal. The re-use of computer equipment plays an important role in Chile. An appropriate recycling scheme will have to be introduced to provide adequate solutions for the growing rate of e-waste generation.

  7. Annual flow duration curves assessment in ephemeral small basins

    Science.gov (United States)

    Pumo, D.; Viola, F.; La Loggia, G.; Noto, L. V.

    2014-11-01

    Flow duration curve (FDC) represents a comprehensive signature of temporal runoff variability often used to synthesize catchment rainfall-runoff responses. A new model, the ModABa (MODel for Annual flow duration curves assessment in ephemeral small BAsins), is here introduced. It can be thought as a wide mosaic whose tesserae are frameworks, models or conceptual schemes separately developed in different studies and harmoniously interconnected with the final aim of reproducing the annual FDC in intermittent small catchments. Two separated seasons within the hydrological year are distinguished: a dry season, characterized by absence of streamflow, and a non-zero season. Streamflow is disaggregated into a subsurface component and a surface component that, in turn, is considered formed by two different contributions: impervious runoff and surface runoff from permeable areas induced by heavy rains. The FDCs of the two streamflow components are first separately and differently computed, and then combined to obtain the non-zero FDC. This last, together with the estimated probability of null streamflow, allows the annual FDC assessment through the theory of total probability. The ModABa is here tested on a small Italian catchment and the results show how the model, once calibrated, is able to accurately reproduce the empirical FDC for the analyzed case, starting from easily derivable parameters and commonly available climatic data. In this sense, the model reveals itself as a valid tool, potentially suitable for predictions at ungauged basins in a regionalization framework.

  8. Clinical features and risk assessment for cardiac surgery in adult congenital heart disease: Three years at a single Japanese center

    Directory of Open Access Journals (Sweden)

    Satoshi Kurokawa

    2014-04-01

    Conclusion: Cardiac surgery could be safely performed in most ACHD cases. Exercise tolerance testing can be useful in identifying patients at high risk of mortality or major complications. BNP can be valuable in predicting poor outcomes after cardiac surgery.

  9. Noninvasive assessment of treatment of cardiac allograft rejection with indium-111-labeled lymphocytes

    Energy Technology Data Exchange (ETDEWEB)

    Rosenbloom, M.; Eisen, H.J.; Laschinger, J.; Saffitz, J.E.; Sobel, B.E.; Bergmann, S.R.; Bolman, R.M. III

    1988-09-01

    We have shown previously that cardiac allograft rejection can be detected noninvasively with gamma scintigraphy after administration of indium-111 (111In)-labeled lymphocytes. To determine whether this technique could be used to monitor salvage immunosuppressive therapy in reversing rejection, 5 dogs were studied after thoracic heterotopic cardiac transplantation. Initial postoperative immunosuppression was maintained with cyclosporine (10-20 mg/kg/day) and prednisone (1 mg/kg/day) for 7 days after transplantation and then discontinued. Scintigraphy after administration of labeled lymphocytes was performed during initial immunosuppression and every 3 days after its termination. Endomyocardial biopsies were obtained on each day scintigraphy was performed. Once scintigraphic criteria for rejection were met (111In-lymphocyte uptake greater than mean +/- 2SD of normal myocardium), animals were treated with high dose methylprednisolone and cyclosporine. Myocardial 111In-lymphocyte activity compared with that in blood was 0.7 +/- 0.8 during initial immunosuppression, increased to 5.7 +/- 3.5 after termination of therapy (P less than 0.01), and diminished with salvage immunosuppressive therapy to 0.5 +/- 0.8 (P = NS compared with native hearts or allografts during initial immunosuppression). Scintigraphy accurately predicted all but one episode of biopsy-documented rejection and accurately detected reversal of rejection during salvage. Thus, scintigraphy with 111In-labeled lymphocytes should facilitate noninvasive monitoring of antirejection therapy in patients.

  10. Assessment of maternal cerebral blood flow in patients with preeclampsia

    Directory of Open Access Journals (Sweden)

    Mandić Vesna

    2005-01-01

    Full Text Available Introduction Systemic vasoconstrktion in preeclamptic patients increases vascular resistance, and is manifested by increased arterial blood flow velocity. The aim of the study is to evaluate if there is a change of Doppler indices in maternal medial cerbral artery (MCA in severe preeclampsia due to: 1 severity of clinical symptoms, 2 the beginning of eclamptic attack and 3 the application of anticonvidsive therapy. Material and methods A prospective clinical study included 92 pregnant women, gestational age 28-36 weeks. They were divided into three groups: normotensive (n=30, mild preeclampsia (n=33, and severe preeclampsia (n=29. We investigated maternal cerebral circulation by assessing the MCA. We registrated: pulsatility index (Pi, resistance index (Ri, Systolic/diastolic ratio (S/D, and the maximum systolic, end diastolic and medium velocity. Patients with severe preeclampsia were divided into two subgroups: subgroup 1 included patients without symptoms of threatening eclampsia (n=18; 62.06%; while subgroup 2 included those with symptoms of preeclampsia (n=11; 37.94%. All patients with severe preeclampsia were treated with magnesium sulfate (MgSO4, and cerebral blood flow was measured before and after the treatment. Statistical analysis was done by oneway ANOVA, Student t-test and t-paired sample test. The difference was considered to be significant if p < 0.05. Results Significantly increased Pi, Ri and all velocities were established in the group of patients with severe preeclampsia compared with the other two groups. In the group with severe preeclamsia we registrated significantly increased values of all velocities (patients with signs of threatening eclampsia. After MgSO4 treatment in patients with severe preeclampsia significantly decreased values of Pi, Ri, S/D ratio and all velocities were registered. Discussion In the studied group of patients with severe preclampsia we found increased velocity values, Pi and Ri, especially in

  11. Assessment of sub-clinical acute cellular rejection after heart transplantation: comparison of cardiac magnetic resonance imaging and endomyocardial biopsy

    Energy Technology Data Exchange (ETDEWEB)

    Krieghoff, Christian; Hildebrand, Lysann; Grothoff, Matthias; Lehmkuhl, Lukas; Luecke, Christian; Andres, Claudia; Nitzsche, Stefan; Riese, Franziska; Gutberlet, Matthias [University Leipzig - Heart Centre, Department of Diagnostic and Interventional Radiology, Leipzig (Germany); Barten, Markus J.; Strueber, Martin; Mohr, Friedrich Wilhelm [University Leipzig - Heart Centre, Department of Cardiac Surgery, Leipzig (Germany)

    2014-10-15

    Comparing the diagnostic value of multi-sequential cardiac magnetic resonance imaging (CMR) with endomyocardial biopsy (EMB) for sub-clinical cardiac allograft rejection. One hundred and forty-six examinations in 73 patients (mean age 53 ± 12 years, 58 men) were performed using a 1.5 Tesla system and compared to EMB. Examinations included a STIR (short tau inversion recovery) sequence for calculation of edema ratio (ER), a T1-weighted spin-echo sequence for assessment of global relative enhancement (gRE), and inversion-recovery sequences to visualize late gadolinium enhancement (LGE). Histological grade ≥1B was considered relevant rejection. One hundred and twenty-seven (127/146 = 87 %) EMBs demonstrated no or mild signs of rejection (grades ≤1A) and 19/146 (13 %) a relevant rejection (grade ≥1B). Sensitivity, specificity, positive predictive, and negative predictive values were as follows: ER: 63 %, 78 %, 30 %, and 93 %; gRE: 63 %, 70 %, 24 %, and 93 %; LGE: 68 %, 36 %, 13 %, and 87 %; with the combination of ER and gRE with at least one out of two positive: 84 %, 57 %, 23 %, and 96 %. ROC analysis revealed an area under the curve of 0.724 for ER and 0.659 for gRE. CMR parameters for myocarditis are useful to detect sub-clinical acute cellular rejection after heart transplantation. Comparable results to myocarditis can be achieved with a combination of parameters. (orig.)

  12. Assessment of normal left atrial appendage anatomy and function over gender and ages by dynamic cardiac CT

    Energy Technology Data Exchange (ETDEWEB)

    Boucebci, Samy; Velasco, Stephane; Duboe, Pier-Olivier; Tasu, Jean-Pierre [University of Poitiers, University Hospital, Department of Radiology, Poitiers (France); Pambrun, Thomas [University of Poitiers, University Hospital, Department of Cardiology, Poitiers (France); Ingrand, Pierre [University of Poitiers, University Institute of Public Health, Poitiers (France)

    2016-05-15

    The aim of this study was to evaluate variations in anatomy and function according to age and gender using cardiac computed tomography (CT) in a large prospective cohort of healthy patients. The left atrial appendage (LAA) is considered the most frequent site of intracardiac thrombus formation. However, variations in normal in vivo anatomy and function according to age and gender remain largely unknown. Three-dimensional (3D) cardiac reconstructions of the LAA were performed from CT scans of 193 consecutive patients. Parameters measured included LAA number of lobes, anatomical position of the LAA tip, angulation measured between the proximal and distal portions, minimum (iVol{sub min}) and maximum (iVol{sub max}) volumes indexed to body surface area (BSA), and ejection fraction (LAAEF). Relationship with age was assessed for each parameter. We found that men had longer and wider LAAs. The iVol{sub min} and iVol{sub max} increased by 0.23 and 0.19 ml per decade, respectively, while LAAEF decreased by 2 % per decade in both sexes. Although LAA volumes increase, LAAEF decreases with age in both sexes. (orig.)

  13. Cardiac fusion and complex congenital cardiac defects in thoracopagus twins: diagnostic value of cardiac CT

    Energy Technology Data Exchange (ETDEWEB)

    Goo, Hyun Woo [University of Ulsan College of Medicine, Asan Medical Center, Department of Radiology and Research Institute of Radiology, Seoul (Korea, Republic of); Park, Jeong-Jun [University of Ulsan College of Medicine, Asan Medical Center, Department of Pediatric Cardiac Surgery, Seoul (Korea, Republic of); Kim, Ellen Ai-Rhan [University of Ulsan College of Medicine, Asan Medical Center, Division of Neonatology, Department of Pediatrics, Seoul (Korea, Republic of); Won, Hye-Sung [University of Ulsan College of Medicine, Asan Medical Center, Department of Obstetrics and Gynecology, Seoul (Korea, Republic of)

    2014-09-15

    Most thoracopagus twins present with cardiac fusion and associated congenital cardiac defects, and assessment of this anatomy is of critical importance in determining patient care and outcome. Cardiac CT with electrocardiographic triggering provides an accurate and quick morphological assessment of both intracardiac and extracardiac structures in newborns, making it the best imaging modality to assess thoracopagus twins during the neonatal period. In this case report, we highlight the diagnostic value of cardiac CT in thoracopagus twins with an interatrial channel and complex congenital cardiac defects. (orig.)

  14. Cardiovascular devices; reclassification of intra-aortic balloon and control systems for acute coronary syndrome, cardiac and non-cardiac surgery, or complications of heart failure; effective date of requirement for premarket approval for intra-aortic balloon and control systems for septic shock or pulsatile flow generation. Final order.

    Science.gov (United States)

    2013-12-30

    The Food and Drug Administration (FDA) is issuing a final order to reclassify intra-aortic balloon and control system (IABP) devices when indicated for acute coronary syndrome, cardiac and non-cardiac surgery, or complications of heart failure, a preamendments class III device, into class II (special controls), and to require the filing of a premarket approval application (PMA) or a notice of completion of a product development protocol (PDP) for IABPs when indicated for septic shock or pulsatile flow generation.

  15. Databases for assessing the outcomes of the treatment of patients with congenital and paediatric cardiac disease - the perspective of cardiac surgery

    NARCIS (Netherlands)

    Jacobs, Marshall Lewis; Jacobs, Jeffrey Phillip; Franklin, Rodney C. G.; Mavroudis, Constantine; Lacour-Gayet, Francois; Tchervenkov, Christo I.; Walters, Hal; Bacha, Emile A.; Clarke, David Robinson; Gaynor, J. William; Spray, Thomas L.; Stellin, Giovanni; Ebels, Tjark; Maruszewski, Bohdan; Tobota, Zdzislaw; Kurosawa, Hiromi; Elliott, Martin

    2008-01-01

    This review includes a brief discussion, from the perspective of cardiac surgeons, of the rationale for creation and maintenance of multi-institutional databases of outcomes of congenital heart Surgery, together with a history of the evolution of such databases, a description of the current state of

  16. The role of out-of-hospital cardiac arrest in predicting hospital mortality for percutaneous coronary interventions in the Clinical Outcomes Assessment Program.

    Science.gov (United States)

    Maynard, Charles; Rao, Sunil V; Gregg, Mary; Phillips, Richard C; Reisman, Mark; Tucker, Eben; Goss, J Richard

    2009-01-01

    Published mortality models for percutaneous coronary intervention (PCI), including the Clinical Outcomes Assessment Program (COAP) model, have not considered the effect of out-ofhospital cardiac arrest. The primary objective of this study was to determine if the inclusion of out-of-hospital cardiac arrest altered the COAP mortality model for PCI. The COAP PCI database contains extensive demographic, clinical, procedural and outcome information, including out-of-hospital cardiac arrest, which was added to the data collection form in 2006. This study included 15,586 consecutive PCIs performed in 31 Washington State hospitals in 2006. Using development and test sets, the existing COAP PCI logistic regression mortality model was examined to assess the effect of out-of-hospital arrest on in-hospital mortality. Overall, 2% of individuals undergoing PCI had cardiac arrest prior to hospital arrival. Among 8 hospitals with PCI volumes 120 cases per year did. In-hospital mortality was 19% in the arrest group and was 1.0% in remaining procedures (p < 0.0001). In the new multivariate model, out-of-hospital cardiac arrest was highly associated with mortality (odds ratio = 5.50; 95% confidence interval [CI] = 3.28-9.25). When evaluated in the test set, the new model had excellent discrimination (c-statistic = 0.89; 95% CI = 0.85-0.93). Out-of-hospital cardiac arrest is an important determinant of risk-adjusted in-hospital mortality for PCI, particularly for hospitals with low volumes and relatively high volumes of cardiac arrest cases.

  17. Role of speckle tracking imaging in the assessment of myocardial regional ventricular function in experimental blunt cardiac injury

    Institute of Scientific and Technical Information of China (English)

    Wen-Hua Du; Xiang Wang; Xiu-Qin Xiong; Tao Li; Hua-Ping Liang

    2015-01-01

    Purpose:To evaluate the usefulness and information collecting ability of speckle tracking imaging techniques in the assessment of myocardial regional ventricular contractility in a rabbit model with blunt cardiac injury.Methods:Fifteen healthy New Zealand rabbits weighing (2.70 ± 0.28) kg were anesthetized (3% pentobarbital sodium/i.v) and impacted using the BIM-Ⅱ biological impact machine to induce myocardial contusion (MC).Hemodynamic parameters,such as heart rate,systolic pressure,mean arterial pressure,diastolic pressure and central venous pressure,were determined before and after MC.Further,parameters reflecting left ventricular functions,such as left ventricular end systolic pressure,left ventricular end diastolic pressure,isovolumic pressure (IP) and the maximal increasing/decreasing rate of left intraventricular pressure (±dp/dtmax),were also determined before and after MC.Left ventricular functions were determined either by two dimensional transthoracic echocardiography or by speckle tracking imaging for segmental abnormal ventricular wall motions.Results:Heart rate,systolic pressure,diastolic pressure and mean arterial pressure decreased significantly but transiently,while central venous pressure markedly increased after MC.In contrast to significant changes in diastolic functions,there was no significant change in cardiac systolic functions after MC.The speckle tracking imaging demonstrated that strain values of different myocardial segment significantly decreased post impact,and that of the ventricular segment decreased from segment to segment.Conclusion:Speckle tracking imaging is useful and informative to assess myocardial regional dysfunctions post MC.

  18. CIS-Based Risk Assessment of Debris Flow Disasters in the Upper Reach of Yangtze River

    Institute of Scientific and Technical Information of China (English)

    HAN Yongshun; LIU Hongjiang; ZHONG Dunlun; SU Fenghuan; LI Chaokui

    2007-01-01

    This paper discussed theory and methodologies of debris-flow risk assessment and established an implementation process according to indicators of debris-flow hazard degree, vulnerability, risk degree, etc. Among these methodologies, historical and potential hazard degree was comprehensively considered into hazard assessment and hazard index was presented to indicate the debris-flow hazard degree. Regarding debris-flow vulnerability assessment, its statistical data and calculating procedure were based on the hazard-degree regionalization instead of administrative divisions, which improved the assessing scientificity and precision. These quantitative methodologies integrated with Geography Information System (GIS) were applied to the risk assessment of debris flows in the upper reach of Yangtze River. Its results were in substantial agreement on investigation data and the actual distribution of debris flows, which showed that these principles and methodologies were reasonable and feasible and can provide basis or reference for debris-flow risk assessment and disaster management.

  19. Image-based assessment of fractional flow reserve.

    Science.gov (United States)

    Tu, Shengxian; Bourantas, Christos V; Nørgaard, Bjarne L; Kassab, Ghassan S; Koo, Bon-Kwon; Reiber, Johan H C

    2015-01-01

    Pressure-derived fractional flow reserve (FFR) is an index of the haemodynamic significance of a coronary lesion. Numerous studies have provided robust evidence that FFR-guided percutaneous coronary intervention is associated with better clinical outcomes and reduces the need for repeat revascularisation. Although FFR is regarded as the gold standard for assessing lesion severity, it has limited clinical applications, mainly because it is a relatively expensive and time-consuming procedure. To overcome these limitations, several computational-based methodologies have been developed which enable estimation of the FFR in three-dimensional models derived from anatomic imaging data. Multislice computed tomographic coronary angiography and quantitative coronary angiography have been proposed for coronary reconstruction and computational evaluation of the FFR. In this review article, we describe the currently available methodologies for the computational estimation of FFR, present evidence derived from their clinical evaluations, stress their limitations, and discuss their potential value in clinical practice.

  20. Review and assessment of turbulence models for hypersonic flows

    Science.gov (United States)

    Roy, Christopher J.; Blottner, Frederick G.

    2006-10-01

    Accurate aerodynamic prediction is critical for the design and optimization of hypersonic vehicles. Turbulence modeling remains a major source of uncertainty in the computational prediction of aerodynamic forces and heating for these systems. The first goal of this article is to update the previous comprehensive review of hypersonic shock/turbulent boundary-layer interaction experiments published in 1991 by Settles and Dodson (Hypersonic shock/boundary-layer interaction database. NASA CR 177577, 1991). In their review, Settles and Dodson developed a methodology for assessing experiments appropriate for turbulence model validation and critically surveyed the existing hypersonic experiments. We limit the scope of our current effort by considering only two-dimensional (2D)/axisymmetric flows in the hypersonic flow regime where calorically perfect gas models are appropriate. We extend the prior database of recommended hypersonic experiments (on four 2D and two 3D shock-interaction geometries) by adding three new geometries. The first two geometries, the flat plate/cylinder and the sharp cone, are canonical, zero-pressure gradient flows which are amenable to theory-based correlations, and these correlations are discussed in detail. The third geometry added is the 2D shock impinging on a turbulent flat plate boundary layer. The current 2D hypersonic database for shock-interaction flows thus consists of nine experiments on five different geometries. The second goal of this study is to review and assess the validation usage of various turbulence models on the existing experimental database. Here we limit the scope to one- and two-equation turbulence models where integration to the wall is used (i.e., we omit studies involving wall functions). A methodology for validating turbulence models is given, followed by an extensive evaluation of the turbulence models on the current hypersonic experimental database. A total of 18 one- and two-equation turbulence models are reviewed

  1. Evaluation of changes of intracranial blood flow after carotid artery stenting using digital subtraction angiography flow assessment

    Institute of Scientific and Technical Information of China (English)

    Hajime; Wada; Masato; Saito; Kyousuke; Kamada

    2015-01-01

    AIM: To evaluate the changes of intracranial blood flow after carotid artery stenting(CAS), using the flow assessment application "Flow-Insight", which was developed in our department.METHODS: Twenty patients treated by CAS participated in this study. We analyzed the change in concentration of the contrast media at the anterior-posterior and profile view image with the flow assessment application "Flow-Insight". And we compared the results with N-isopropyl-p-[123I] iodoamphetamine-single-photon emission computed tomography(IMP SPECT) performed before and after the treatment. RESULTS: From this study, 200% of the parameter "blood flow" change in the post/pre-treatment is suggested as the critical line of the hyperperfusion syndrome arise. Although the observed blood flow increase in the digital subtraction angiography system did not strongly correlate with the rate of increase of SPECT, the "Flow-Insight" reflected the rate of change of the vessels well. However, for patients with reduced reserve blood flow before CAS, a highly elevated site was in agreement with the site analysis results. CONCLUSION: We concluded that the cerebral angiography flow assessment application was able to more finely reveal hyperperfusion regions in the brain after CAS compared to SPECT.

  2. Assessment of intramural blood flow and neurogenic control in intact and hypertrophic urinary bladder with harmonic analysis of bioimpedance in rats.

    Science.gov (United States)

    Kirpatovsky, V I; Mudraya, I S; Revenko, S V; Nesterov, A V; Gavrilov, I Yu; Khromov, R A; Bablumyan, A Yu

    2012-08-01

    High-resolution impedancometry and harmonic (Fourier) analysis of variable component of bioimpedance revealed rhythmic oscillations of urinary bladder bioimpedance at the Mayer wave, respiration, and heartbeat frequencies. The power values of the corresponding Mayer, respiratory, and cardiac peaks were calculated to assess circulation in the urinary bladder wall and its autonomic nervous control at various stages of infusion cystometry in intact rats and in the rats with preliminary formed infravesical obstruction (IVO). In intact rats, filling of the bladder with physiological saline diminished the power of the first (fundamental) cardiac peak attesting to a decrease of the blood flow in the bladder wall. Simultaneously, the power of low-frequency Mayer peak reflecting sympathetic activity increased, while the power of respiratory peak decreased supposedly reflecting abatement of the parasympathetic influences. Bladder voiding was accompanied by a decrease of Mayer peak and increase of the respiratory one. Prior to infusion cystometry, the intravesical pressure in IVO rats was elevated while the power of fundamental cardiac peak was below the control value. Filling the bladder in these rats was accompanied by further decrease of the cardiac peak reflecting still greater drop in blood supply. In control rats, voiding the bladder normalized the vesical circulation assessed by the cardiac peak, while in IVO rats this peak remained decreased. The reciprocal changes of Mayer and respiratory peaks observed during infusion cystometry in the norm were replaced by unidirectional decrease in the power of both peaks in IVO rats, which probably attest to disturbance of autonomic nervous control in the hypertrophic urinary bladder in these rats.

  3. Cardiac magnetic resonance, transthoracic and transoesophageal echocardiography: a comparison of in vivo assessment of ventricular function in rats.

    Science.gov (United States)

    Richardson, J D; Bertaso, A G; Frost, L; Psaltis, P J; Carbone, A; Koschade, B; Wong, D T; Nelson, A J; Paton, S; Williams, K; Azarisman, S; Worthley, M I; Teo, K S; Gronthos, S; Zannettino, A C W; Worthley, S G

    2013-10-01

    In vivo assessment of ventricular function in rodents has largely been restricted to transthoracic echocardiography (TTE). However 1.5 T cardiac magnetic resonance (CMR) and transoesophageal echocardiography (TOE) have emerged as possible alternatives. Yet, to date, no study has systematically assessed these three imaging modalities in determining ejection fraction (EF) in rats. Twenty rats underwent imaging four weeks after surgically-induced myocardial infarction. CMR was performed on a 1.5 T scanner, TTE was conducted using a 9.2 MHz transducer and TOE was performed with a 10 MHz intracardiac echo catheter. Correlation between the three techniques for EF determination and analysis reproducibility was assessed. Moderate-strong correlation was observed between the three modalities; the greatest between CMR and TOE (intraclass correlation coefficient (ICC) = 0.89), followed by TOE and TTE (ICC = 0.70) and CMR and TTE (ICC = 0.63). Intra- and inter-observer variations were excellent with CMR (ICC = 0.99 and 0.98 respectively), very good with TTE (0.90 and 0.89) and TOE (0.87 and 0.84). Each modality is a viable option for evaluating ventricular function in rats, however the high image quality and excellent reproducibility of CMR offers distinct advantages even at 1.5 T with conventional coils and software.

  4. Water Resource Inventory and Assessment - Flow Map Poster: Ankeny National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This flow map depicts the flow and control of water on Ankeny National Wildlife Refuge. It was produced as part of the Water Resource Inventory and Assessment...

  5. Predictive value of assessing diastolic strain rate on survival in cardiac amyloidosis patients with preserved ejection fraction.

    Directory of Open Access Journals (Sweden)

    Dan Liu

    Full Text Available Since diastolic abnormalities are typical findings of cardiac amyloidosis (CA, we hypothesized that speckle-tracking-imaging (STI derived longitudinal early diastolic strain rate (LSRdias could predict outcome in CA patients with preserved left ventricular ejection fraction (LVEF >50%.Diastolic abnormalities including altered early filling are typical findings and are related to outcome in CA patients. Reduced longitudinal systolic strain (LSsys assessed by STI predicts increased mortality in CA patients. It remains unknown if LSRdias also related to outcome in these patients.Conventional echocardiography and STI were performed in 41 CA patients with preserved LVEF (25 male; mean age 65±9 years. Global and segmental LSsys and LSRdias were obtained in six LV segments from apical 4-chamber views.Nineteen (46% out of 41 CA patients died during a median of 16 months (quartiles 5-35 months follow-up. Baseline mitral annular plane systolic excursion (MAPSE, 6 ± 2 vs. 8 ± 3 mm, global LSRdias and basal-septal LSRdias were significantly lower in non-survivors than in survivors (all p < 0.05. NYHA class, number of non-cardiac organs involved, MAPSE, mid-septal LSsys, global LSRdias, basal-septal LSRdias and E/LSRdias were the univariable predictors of all-cause death. Multivariable analysis showed that number of non-cardiac organs involved (hazard ratio [HR] = 1.96, 95% confidence interval [CI] 1.17-3.26, P = 0.010, global LSRdias (HR = 7.30, 95% CI 2.08-25.65, P = 0.002, and E/LSRdias (HR = 2.98, 95% CI 1.54-5.79, P = 0.001 remained independently predictive of increased mortality risk. The prognostic performance of global LSRdias was optimal at a cutoff value of 0.85 S-1 (sensitivity 68%, specificity 67%. Global LSRdias < 0.85 S-1 predicted a 4-fold increased mortality in CA patients with preserved LVEF.STI-derived early diastolic strain rate is a powerful independent predictor of survival in CA patients with preserved LVEF.

  6. Scintigraphic assessment of regional cardiac sympathetic nervous system in patients with single-vessel coronary artery disease

    Energy Technology Data Exchange (ETDEWEB)

    Sakata, Kazuyuki; Yoshida, Hiroshi; Nawada, Ryuzo; Obayashi, Kazuhiko; Tamekiyo, Hiromichi; Mochizuki, Mamoru [Shizuoka General Hospital (Japan)

    2000-06-01

    In coronary artery disease, the cardiac sympathetic nervous system is closely associated with myocardial ischemia. I-123 metaiodobenzylguanidine (MIBG) imaging allows us to assess the cardiac sympathetic nervous system regionally. One-hundred and eleven patients with single-vessel disease underwent regional quantitative analysis of MIBG imaging before successful percutaneous transluminal coronary angioplasty (PTCA), and repeat angiography 6 months after PTCA. Based on the results of the follow-up left ventriculogram, patients were divided into 3 groups: 39 angina pectoris (AP), 48 prior myocardial infarction without asynergy (MI without asynergy) and 24 prior myocardial infarction with asynergy (Ml with asynergy). AP and MI without asynergy had significant correlations between uptake parameters and regional washout in the territory of diseased vessels, among which the severity score in AP was the most closely correlated with regional washout (r=0.79, p<0.0001). These correlations disappeared in MI with asynergy. To compare regional MIBG parameters in the territory of the diseased vessel as well as in the territories of the other major coronary arteries among the 3 groups, we examined MIBG parameters in 57 patients with left anterior descending artery (LAD) disease selected from among the study patients. Regional washout in the territory of the LAD was significantly higher in the MI without asynergy group than in the other two groups. The left circumflex artery (LCX) region showed significantly reduced MlBG uptake and an increased extent score in the MI with asynergy group compared with the AP group, although only a difference in the extent score existed between the MI with asynergy group and the AP group in the right coronary artery (RCA) region. In addition, the global ejection fraction before PTCA showed a significant negative correlation with each regional washout rate. In this way, regional quantitative analysis of MIBG imaging can detect the regional

  7. Estimation of cardiac motion in cine-MRI sequences by correlation transform optical flow of monogenic features distance

    Science.gov (United States)

    Gao, Bin; Liu, Wanyu; Wang, Liang; Liu, Zhengjun; Croisille, Pierre; Delachartre, Philippe; Clarysse, Patrick

    2016-12-01

    Cine-MRI is widely used for the analysis of cardiac function in clinical routine, because of its high soft tissue contrast and relatively short acquisition time in comparison with other cardiac MRI techniques. The gray level distribution in cardiac cine-MRI is relatively homogenous within the myocardium, and can therefore make motion quantification difficult. To ensure that the motion estimation problem is well posed, more image features have to be considered. This work is inspired by a method previously developed for color image processing. The monogenic signal provides a framework to estimate the local phase, orientation, and amplitude, of an image, three features which locally characterize the 2D intensity profile. The independent monogenic features are combined into a 3D matrix for motion estimation. To improve motion estimation accuracy, we chose the zero-mean normalized cross-correlation as a matching measure, and implemented a bilateral filter for denoising and edge-preservation. The monogenic features distance is used in lieu of the color space distance in the bilateral filter. Results obtained from four realistic simulated sequences outperformed two other state of the art methods even in the presence of noise. The motion estimation errors (end point error) using our proposed method were reduced by about 20% in comparison with those obtained by the other tested methods. The new methodology was evaluated on four clinical sequences from patients presenting with cardiac motion dysfunctions and one healthy volunteer. The derived strain fields were analyzed favorably in their ability to identify myocardial regions with impaired motion.

  8. Cardiac remodeling following percutaneous mitral valve repair - initial results assessed by cardiovascular magnetic resonance imaging

    DEFF Research Database (Denmark)

    Radunski, U K; Franzen, O; Barmeyer, A

    2014-01-01

    (CMR) to assess reverse myocardial remodeling in patients after MitraClip implantation. MATERIALS AND METHODS: 12 patients underwent CMR at baseline (BL) before and at 6 months follow-up (FU) after MitraClip implantation. Cine-CMR was performed in short- and long-axes for the assessment of left...

  9. Novel cardiac nuclear magnetic resonance method for noninvasive assessment of myocardial fibrosis in hemodialysis patients.

    Science.gov (United States)

    Graham-Brown, Matthew P M; March, Daniel S; Churchward, Darren R; Stensel, David J; Singh, Anvesha; Arnold, Ranjit; Burton, James O; McCann, Gerry P

    2016-10-01

    Left ventricular hypertrophy and myocardial fibrosis frequently occur in patients with end-stage renal disease receiving hemodialysis therapy and are associated with poor prognosis. Native T1 mapping is a novel cardiac magnetic resonance imaging technique that measures native myocardial T1 relaxation, a surrogate of myocardial fibrosis. Here we compared global and segmental native myocardial T1 time and global longitudinal, circumferential and segmental strain, and cardiac function of 35 hemodialysis patients and 22 control individuals. The median native global T1 time was significantly higher in the hemodialysis than the control group (1270 vs. 1085 ms), with the septal regions of hemodialysis patients having significantly higher median T1 times than nonseptal regions (1293 vs. 1252 ms). The mean peak global circumferential strain and global longitudinal strain were both significantly reduced in hemodialysis patients compared with controls (-18.3 vs. -21.7 and -16.1 vs. -20.4, respectively). Systolic strain was also significantly reduced in the septum compared with the nonseptal myocardium in hemodialysis patients (-16.2 vs. -21.9) but not in control subjects. Global circumferential strain and longitudinal strain significantly correlated with global native T1 values (r = 0.41 and 0.55, respectively), and the septal native T1 significantly correlated with the septal systolic strain (r = 0.46). Thus, myocardial fibrosis may be assessed noninvasively with native T1 mapping; the interventricular septum appears to be particularly prone to the development of fibrosis in hemodialysis patients.

  10. Intra- and inter-reader reproducibility of blood flow measurements on the ascending aorta and pulmonary artery using cardiac magnetic resonance.

    Science.gov (United States)

    Di Leo, Giovanni; D'Angelo, Ida Daniela; Alì, Marco; Cannaò, Paola Maria; Mauri, Giovanni; Secchi, Francesco; Sardanelli, Francesco

    2017-03-01

    The aim of our study was to estimate the intra- and inter-reader reproducibility of blood flow measurements in the ascending aorta and main pulmonary artery using cardiac magnetic resonance (CMR) and a semi-automated segmentation method. The ethics committee approved this retrospective study. A total of 50 consecutive patients (35 males and 15 females; mean age±standard deviation 27±13 years) affected by congenital heart disease were reviewed. They underwent CMR for flow analysis of the ascending aorta and main pulmonary artery (1.5 T, through-plane phase-contrast sequences). Two independent readers (R1, trained radiology resident; R2, lower-trained technician student) obtained segmented images twice (>10-day interval), using a semi-automated method of segmentation. Peak velocity, forward and backward flows were obtained. Bland-Altman analysis was used and reproducibility was reported as complement to 100% of the ratio between the coefficient of repeatability and the mean. R1 intra-reader reproducibility for the aorta was 99% (peak velocity), 95% (forward flow) and 49% (backward flow); for the pulmonary artery, 99%, 91% and 90%, respectively. R2 intra-reader reproducibility was 92%, 91% and 38%; 98%, 86% and 87%, respectively. Inter-reader reproducibility for the aorta was 91%, 85% and 20%; for the pulmonary artery 96%, 75%, and 82%, respectively. Our results showed a good to excellent reproducibility of blood flow measurements of CMR together with a semiautomated method of segmentation, for all variables except the backward flow of the ascending aorta, with a limited impact of operator's training.

  11. Optical coherence tomography provides an ability to assess mechanical property of cardiac wall of developing outflow tract in embryonic heart in vivo

    Science.gov (United States)

    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.

  12. Linking water quality and quantity in environmental flow assessment in deteriorated ecosystems: a food web view.

    Science.gov (United States)

    Chen, He; Ma, Lekuan; Guo, Wei; Yang, Ying; Guo, Tong; Feng, Cheng

    2013-01-01

    Most rivers worldwide are highly regulated by anthropogenic activities through flow regulation and water pollution. Environmental flow regulation is used to reduce the effects of anthropogenic activities on aquatic ecosystems. Formulating flow alteration-ecological response relationships is a key factor in environmental flow assessment. Traditional environmental flow models are characterized by natural relationships between flow regimes and ecosystem factors. However, food webs are often altered from natural states, which disturb environmental flow assessment in such ecosystems. In ecosystems deteriorated by heavy anthropogenic activities, the effects of environmental flow regulation on species are difficult to assess with current modeling approaches. Environmental flow management compels the development of tools that link flow regimes and food webs in an ecosystem. Food web approaches are more suitable for the task because they are more adaptive for disordered multiple species in a food web deteriorated by anthropogenic activities. This paper presents a global method of environmental flow assessment in deteriorated aquatic ecosystems. Linkages between flow regimes and food web dynamics are modeled by incorporating multiple species into an ecosystem to explore ecosystem-based environmental flow management. The approach allows scientists and water resources managers to analyze environmental flows in deteriorated ecosystems in an ecosystem-based way.

  13. Computed tomography assessment of lung structure in patients undergoing cardiac surgery with cardiopulmonary bypass

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, R.R.; Sawada, A.Y.; Fukuda, M.J.; Neves, F.H.; Carmona, M.J.; Auler, J.O.; Malbouisson, L.M.S., E-mail: malbouisson@hcnet.usp.b [Universidade de Sao Paulo (USP), SP (Brazil). Faculdade de Medicina. Hospital das Clinicas; Pelosi, P. [Universita' degli Studi dell' Insubria, Varese (Italy). Dipt. Ambiente, Salute e Sicurezza; Rouby, J.-J. [University Pierre and Marie Curie, Paris (France). La Pitie Salpetriere Hospital. Dept. of Anesthesiology and Critical Care and Medicine

    2011-06-15

    Hypoxemia is a frequent complication after coronary artery bypass graft (CABG) with cardiopulmonary bypass (CPB), usually attributed to atelectasis. Using computed tomography (CT), we investigated postoperative pulmonary alterations and their impact on blood oxygenation. Eighteen non-hypoxemic patients (15 men and 3 women) with normal cardiac function scheduled for CABG under CPB were studied. Hemodynamic measurements and blood samples were obtained before surgery, after intubation, after CPB, at admission to the intensive care unit, and 12, 24, and 48 h after surgery. Pre- and postoperative volumetric thoracic CT scans were acquired under apnea conditions after a spontaneous expiration. Data were analyzed by the paired Student t-test and one-way repeated measures analysis of variance. Mean age was 63 {+-} 9 years. The PaO{sub 2}/FiO{sub 2} ratio was significantly reduced after anesthesia induction, reaching its nadir after CPB and partially improving 12 h after surgery. Compared to preoperative CT, there was a 31% postoperative reduction in pulmonary gas volume (P < 0.001) while tissue volume increased by 19% (P < 0.001). Non-aerated lung increased by 253 {+-} 97 g (P < 0.001), from 3 to 27%, after surgery and poorly aerated lung by 72 {+-} 68 g (P < 0.001), from 24 to 27%, while normally aerated lung was reduced by 147 {+-} 119 g (P < 0.001), from 72 to 46%. No correlations (Pearson) were observed between PaO{sub 2}/FiO{sub 2} ratio or shunt fraction at 24 h postoperatively and postoperative lung alterations. The data show that lung structure is profoundly modified after CABG with CPB. Taken together, multiple changes occurring in the lungs contribute to postoperative hypoxemia rather than atelectasis alone. (author)

  14. Assessment of Cardiac Functional Alterations of Ankylosing Spondylitis Patients without Cardiovascular Risk Factors

    Directory of Open Access Journals (Sweden)

    Alper Kepez

    2013-08-01

    Full Text Available Introduction: The aim of this study is to evaluate cardiac functional alterations of ankylosing spondylitis patients without any cardiovascular risk factors.Patients and Methods: Thirty seven consecutive akylosing spondylitis patients without any cardiovascular risk factors constituted our study patient population (age: 41.4 ± 11.1 years, 28 male. Electrocardiographs (ECG of all patients were obtained and all patients underwent comprehensive transthoracic echocardiographic examination. QRS durations, p wave dispersion and corrected QT dispersion (QTcd values were calculated from 12-lead ECG’s. Data reflecting left ventricular systolic and diastolic functions were obtained from echocardiographic examinations. Data of patients were compared with the data of 28 age-and gender matched healthy control subjects (age: 40.1 ± 10.5 years, 19 male.Results: There were no significant differences between patients and controls regarding QRS durations, p wave dispersion and QTcd values. There were also no significant differences between patients and controls regarding parameters reflecting left ventricular systolic and diastolic functions. Annular velocities at mitral and tricuspid annulus levels evaluated with pulsed-wave tissue Doppler imaging were also similar as well. Two (7.2% subjects in the control group and 2 (5.4% patients in the akylosing spondylitis group had minimal aortic regurgitation (p= 0.51. Conclusion: We could not demonstrate any electrocardiographic or echocardiographic evidence of structural myocardial alterations in a small sample of akylosing spondylitis patients free of cardiovascular risk factors. Effects of frequently encountered co-existent cardiovascular risk factors of ankylosing spondylitis patients might have contributed to the conflicting literature data related with this topic.

  15. Canines as sentinel species for assessing chronic exposures to air pollutants: part 2. Cardiac pathology.

    Science.gov (United States)

    Calderón-Garcidueñas, L; Gambling, T M; Acuña, H; García, R; Osnaya, N; Monroy, S; Villarreal-Calderón, A; Carson, J; Koren, H S; Devlin, R B

    2001-06-01

    The principal objective of this study is to evaluate by light and electron microscopy (LM, EM) the heart tissues in stray southwest and northeast metropolitan Mexico City (SWMMC, NEMMC) dogs and compare their findings to those from 3 less polluted cities (Cuernavaca, Tlaxcala, and Tuxpam). Clinically healthy mongrel dogs, including 109 from highly polluted SWMMC and NEMMC, and 43 dogs from less polluted cities were studied. Dogs residing in cities with lower levels of pollutants showed little or no cardiac abnormalities. Mexico City and Cuernavaca dogs exhibited LM myocardial alterations including apoptotic myocytes, endothelial and immune effector cells, degranulated mast cells associated with scattered foci of mononuclear cells in left and right ventricles and interventricular septum, and clusters of adipocytes interspersed with mononuclear cells. Vascular changes included scattered polymorphonuclear leukocytes (PMN) margination and microthrombi in capillaries, and small venous and arteriolar blood vessels. Small veins exhibited smooth muscle cell hyperplasia, and arteriolar blood vessels showed deposition of particulate matter (PM) in the media and adventitia. Unmyelinated nerve fibers showed endoneural and epineural degranulated mast cells. EM examination of myocardial mast cells showed distended and abundant rough endoplasmic reticulum with few secretory granules. Myocardial capillaries exhibited fibrin deposition and their endothelial cells displayed increased luminal and abluminal pinocytic activity and the formation of anemone-like protrusions of the endothelium into the lumen. A close association between myocardial findings, lung epithelial and endothelial pathology, and chronic inflammatory lung changes was noted. The myocardial changes described in dogs exposed to ambient air pollutants may form the basis for developing hypothesis-driven mechanistic studies that might explain the epidemiological data of increased cardiovascular morbidity and mortality in

  16. Unrecognized Myocardial Infarction Assessed by Cardiac Magnetic Resonance Imaging--Prognostic Implications.

    Directory of Open Access Journals (Sweden)

    Anna M Nordenskjöld

    Full Text Available 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.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.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.ClinicalTrials.gov NTC01257282.

  17. Left ventricular modelling: a quantitative functional assessment tool based on cardiac magnetic resonance imaging

    Science.gov (United States)

    Conti, C. A.; Votta, E.; Corsi, C.; De Marchi, D.; Tarroni, G.; Stevanella, M.; Lombardi, M.; Parodi, O.; Caiani, E. G.; Redaelli, A.

    2011-01-01

    We present the development and testing of a semi-automated tool to support the diagnosis of left ventricle (LV) dysfunctions from cardiac magnetic resonance (CMR). CMR short-axis images of the LVs were obtained in 15 patients and processed to detect endocardial and epicardial contours and compute volume, mass and regional wall motion (WM). Results were compared with those obtained from manual tracing by an expert cardiologist. Nearest neighbour tracking and finite-element theory were merged to calculate local myocardial strains and torsion. The method was tested on a virtual phantom, on a healthy LV and on two ischaemic LVs with different severity of the pathology. Automated analysis of CMR data was feasible in 13/15 patients: computed LV volumes and wall mass correlated well with manually extracted data. The detection of regional WM abnormalities showed good sensitivity (77.8%), specificity (85.1%) and accuracy (82%). On the virtual phantom, computed local strains differed by less than 14 per cent from the results of commercial finite-element solver. Strain calculation on the healthy LV showed uniform and synchronized circumferential strains, with peak shortening of about 20 per cent at end systole, progressively higher systolic wall thickening going from base to apex, and a 10° torsion. In the two pathological LVs, synchronicity and homogeneity were partially lost, anomalies being more evident for the more severely injured LV. Moreover, LV torsion was dramatically reduced. Preliminary testing confirmed the validity of our approach, which allowed for the fast analysis of LV function, even though future improvements are possible. PMID:22670208

  18. Three-dimensional binding sites volume assessment during cardiac pacing lead extraction

    Directory of Open Access Journals (Sweden)

    Bich Lien Nguyen

    2015-07-01

    Conclusions: Real-time 3D binding sites assessment is feasible and improves transvenous lead extraction outcomes. Its role as a complementary information requires extensive validation, and might be beneficial for a tailored strategy.

  19. Utility of comprehensive assessment of strain dyssynchrony index by speckle tracking imaging for predicting response to cardiac resynchronization therapy.

    Science.gov (United States)

    Tatsumi, Kazuhiro; Tanaka, Hidekazu; Yamawaki, Kouhei; Ryo, Keiko; Omar, Alaa Mabrouk Salem; Fukuda, Yuko; Norisada, Kazuko; Matsumoto, Kensuke; Onishi, Tetsuari; Gorcsan, John; Yoshida, Akihiro; Kawai, Hiroya; Hirata, Ken-ichi

    2011-02-01

    The strain delay index is reportedly a marker of dyssynchrony and residual myocardial contractility. The aim of this study was to test the hypothesis that a relatively simple version of the strain dyssynchrony index (SDI) can predict response to cardiac resynchronization therapy (CRT) and that combining assessment of radial, circumferential, and longitudinal SDI can further improve the prediction of responders. A total of 52 patients who underwent CRT were studied. The SDI was calculated as the average difference between peak and end-systolic strain from 6 segments for radial and circumferential SDI and 18 segments for longitudinal SDI. Conventional dyssynchrony measures were assessed by interventricular mechanical delay, the Yu index, and radial dyssynchrony by speckle tracking strain. Response was defined as a ≥15% decrease in end-systolic volume after 3 months. Of the individual parameters, radial SDI ≥6.5% was the best predictor of response to CRT, with sensitivity of 81%, specificity of 81%, and an area under the curve of 0.87 (p SDIs was 100%. In contrast, rates in patients with either 1 or no positive SDIs were 42% and 22%, respectively (p SDIs). In conclusion, the SDI can successfully predict response to CRT, and the combined approach leads to more accurate prediction than using individual parameters.

  20. Cardiac MRI assessed left ventricular hypertrophy in differentiating hypertensive heart disease from hypertrophic cardiomyopathy attributable to a sarcomeric gene mutation

    Energy Technology Data Exchange (ETDEWEB)

    Sipola, Petri [Kuopio University Hospital, Department of Clinical Radiology, Kuopio (Finland); University of Eastern Finland, Institute of Clinical Medicine, Faculty of Health Sciences, Kuopio (Finland); Magga, Jarkko; Peuhkurinen, Keijo [Kuopio University Hospital, Department of Medicine, Kuopio (Finland); Husso, Minna [Kuopio University Hospital, Department of Clinical Radiology, Kuopio (Finland); Jaeaeskelaeinen, Pertti; Kuusisto, Johanna [Kuopio University Hospital, Department of Medicine, Kuopio (Finland); Kuopio University Hospital, Heart Center, P.O. Box 1777, Kuopio (Finland)

    2011-07-15

    To evaluate the value of cardiac magnetic resonance imaging (CMRI)-assessed left ventricular hypertrophy (LVH) in differentiating between hypertensive heart disease and hypertrophic cardiomyopathy (HCM). 95 unselected subjects with mild-to-moderate hypertension, 24 patients with HCM attributable to the D175N mutation of the {alpha}-tropomyosin gene and 17 control subjects were studied by cine CMRI. Left ventricular (LV) quantitative and qualitative characteristics were evaluated. LV maximal end-diastolic wall thickness, wall thickness-to-LV volume ratio, end-diastolic septum thickness and septum-to-lateral wall thickness ratio were useful measures for differentiating between LVH due to hypertension and HCM. The most accurate measure for identifying patients with HCM was the LV maximal wall thickness {>=}17 mm, with a sensitivity, specificity, negative predictive value, positive predictive value, and accuracy of 90%, 93%, 86%, 95% and 91%, respectively. LV maximal wall thickness in the anterior wall, or regional bulging in left ventricular wall was found only in patients with HCM. LV mass index was not discriminant between patients with HCM and those with LVH due to hypertension. LV maximal thickness measured by CMRI is the best anatomical parameter in differentiating between LVH due to mild-to-moderate hypertension and HCM attributable to a sarcomeric mutation. CMRI assessment of location and quality of LVH is also of value in differential diagnosis. (orig.)

  1. Influence of cardiac decentralization on cardioprotection.

    Directory of Open Access Journals (Sweden)

    John G Kingma

    Full Text Available The role of cardiac nerves on development of myocardial tissue injury after acute coronary occlusion remains controversial. We investigated whether acute cardiac decentralization (surgical modulates coronary flow reserve and myocardial protection in preconditioned dogs subject to ischemia-reperfusion. Experiments were conducted on four groups of anesthetised, open-chest dogs (n = 32: 1- controls (CTR, intact cardiac nerves, 2- ischemic preconditioning (PC; 4 cycles of 5-min IR, 3- cardiac decentralization (CD and 4- CD+PC; all dogs underwent 60-min coronary occlusion and 180-min reperfusion. Coronary blood flow and reactive hyperemic responses were assessed using a blood volume flow probe. Infarct size (tetrazolium staining was related to anatomic area at risk and coronary collateral blood flow (microspheres in the anatomic area at risk. Post-ischemic reactive hyperemia and repayment-to-debt ratio responses were significantly reduced for all experimental groups; however, arterial perfusion pressure was not affected. Infarct size was reduced in CD dogs (18.6 ± 4.3; p = 0.001, data are mean ± 1 SD compared to 25.2 ± 5.5% in CTR dogs and was less in PC dogs as expected (13.5 ± 3.2 vs. 25.2 ± 5.5%; p = 0.001; after acute CD, PC protection was conserved (11.6 ± 3.4 vs. 18.6 ± 4.3%; p = 0.02. In conclusion, our findings provide strong evidence that myocardial protection against ischemic injury can be preserved independent of extrinsic cardiac nerve inputs.

  2. Measurement and Assessment of Flow Quality in Wind Tunnels Project

    Data.gov (United States)

    National Aeronautics and Space Administration — New wind tunnel flow quality test and analysis procedures have been developed and will be used to establish standardized turbulent flow quality measurement...

  3. Advances in cardiac magnetic resonance imaging of congenital heart disease

    Energy Technology Data Exchange (ETDEWEB)

    Driessen, Mieke M.P. [University of Utrecht, University Medical Center Utrecht, Department of Radiology, PO Box 85500, Utrecht (Netherlands); University of Utrecht, University Medical Center Utrecht, Department of Cardiology, PO Box 85500, Utrecht (Netherlands); The Interuniversity Cardiology Institute of the Netherlands (ICIN) - Netherlands Heart Institute, PO Box 19258, Utrecht (Netherlands); Breur, Johannes M.P.J. [Wilhelmina Children' s Hospital, University Medical Center Utrecht, Department of Pediatric Cardiology, PO Box 85500, Utrecht (Netherlands); Budde, Ricardo P.J.; Oorschot, Joep W.M. van; Leiner, Tim [University of Utrecht, University Medical Center Utrecht, Department of Radiology, PO Box 85500, Utrecht (Netherlands); Kimmenade, Roland R.J. van; Sieswerda, Gertjan Tj [University of Utrecht, University Medical Center Utrecht, Department of Cardiology, PO Box 85500, Utrecht (Netherlands); Meijboom, Folkert J. [University of Utrecht, University Medical Center Utrecht, Department of Cardiology, PO Box 85500, Utrecht (Netherlands); Wilhelmina Children' s Hospital, University Medical Center Utrecht, Department of Pediatric Cardiology, PO Box 85500, Utrecht (Netherlands)

    2015-01-01

    Due to advances in cardiac surgery, survival of patients with congenital heart disease has increased considerably during the past decades. Many of these patients require repeated cardiovascular magnetic resonance imaging to assess cardiac anatomy and function. In the past decade, technological advances have enabled faster and more robust cardiovascular magnetic resonance with improved image quality and spatial as well as temporal resolution. This review aims to provide an overview of advances in cardiovascular magnetic resonance hardware and acquisition techniques relevant to both pediatric and adult patients with congenital heart disease and discusses the techniques used to assess function, anatomy, flow and tissue characterization. (orig.)

  4. Cardiac arrest

    Science.gov (United States)

    ... Article.jsp. Accessed June 16, 2014. Myerburg RJ, Castellanos A. Approach to cardiac arrest and life-threatening ... PA: Elsevier Saunders; 2011:chap 63. Myerburg RJ, Castellanos A. Cardiac arrest and audden aardiac death. In: ...

  5. Pre-pregnancy risk assessment and counselling of the cardiac patient

    NARCIS (Netherlands)

    Pieper, P. G.

    2011-01-01

    Pregnant women with heart disease often have an increased risk of maternal cardiovascular and offspring complications. The magnitude of these risks varies depending on the type and severity of the underlying disease. Therefore risk assessment should be performed before pregnancy. This can be accompl

  6. Multimodality cardiac image analysis for the assessment of coronary artery disease

    NARCIS (Netherlands)

    Gupta, Vikas

    2013-01-01

    Coronary artery disease(CAD) is one of the leading causes of mortality and morbidity worldwide. Clinically, it refers to atherosclerotic changes in the coronary arteries and is usually assessed with a stress electrocardiogram and conventional coronary angiography(CCA). CCA, however, is an invasive t

  7. Absolute assessment of aortic valve stenosis by planimetry using cardiovascular magnetic resonance imaging: Comparison with transoesophageal echocardiography, transthoracic echocardiography, and cardiac catheterisation

    Energy Technology Data Exchange (ETDEWEB)

    Reant, Patricia [Department of Cardiology and Echocardiography, Hopital Cardiologique Haut-Leveque, Bordeaux-Pessac (France); University of Victor Segalen, F33076 Bordeaux (France)]. E-mail: patreant@free.fr; Lederlin, Mathieu [Department of Radiology, Hopital Cardiologique Haut-Leveque, Bordeaux-Pessac (France); University of Victor Segalen, F33076 Bordeaux (France); Lafitte, Stephane [Department of Cardiology and Echocardiography, Hopital Cardiologique Haut-Leveque, Bordeaux-Pessac (France); University of Victor Segalen, F33076 Bordeaux (France); Serri, Karim [Department of Cardiology and Echocardiography, Hopital Cardiologique Haut-Leveque, Bordeaux-Pessac (France); University of Victor Segalen, F33076 Bordeaux (France); Montaudon, Michel [Department of Radiology, Hopital Cardiologique Haut-Leveque, Bordeaux-Pessac (France); University of Victor Segalen, F33076 Bordeaux (France); Inserm E356, F33076 Bordeaux (France); Corneloup, Olivier [Department of Radiology, Hopital Cardiologique Haut-Leveque, Bordeaux-Pessac (France); University of Victor Segalen, F33076 Bordeaux (France); Roudaut, Raymond [Department of Cardiology and Echocardiography, Hopital Cardiologique Haut-Leveque, Bordeaux-Pessac (France); University of Victor Segalen, F33076 Bordeaux (France); Laurent, Francois [Department of Radiology, Hopital Cardiologique Haut-Leveque, Bordeaux-Pessac (France); University of Victor Segalen, F33076 Bordeaux (France); Inserm E356, F33076 Bordeaux (France)

    2006-08-15

    Objective: The aims of this study were to investigate absolute assessment of aortic valve area (AVA), before surgery for aortic stenosis, using cardiovascular magnetic resonance (CMR) in comparison with transoesophageal echocardiography (TEE) and with effective AVA indirectly obtained by routine techniques i.e. transthoracic echocardiography (TTE) and cardiac catheterisation. Materials and methods: Absolute AVA planimetry was performed by TEE and CMR steady state free precession sequences obtained through the aortic valvular plane. Effective AVA was calculated by the continuity equation in TTE and by cardiac catheterisation (Gorlin formula). Results: Thirty-nine patients with aortic valve stenosis, mean age 71.7 {+-} 7.6 years, with a mean AVA of 0.93 {+-} 0.31 cm{sup 2} as measured by TEE, were enrolled in the study. Mean differences were: between CMR and TEE planimetry: d = 0.01 {+-} 0.14 cm{sup 2}, between CMR and cardiac catheterisation: d = 0.05 {+-} 0.13 cm{sup 2}, between CMR and TTE: d = 0.10 {+-} 0.17 cm{sup 2}, between TTE and TEE: d = 0.10 {+-} 0.18 cm{sup 2}, between TTE and cardiac catheterisation: d 0.06 {+-} 0.16 cm{sup 2}, and between TEE and cardiac catheterisation: d = 0.07 {+-} 0.13 cm{sup 2}. Mean intraobserver and interobserver differences of CMR planimetry were d = 0.02 {+-} 0.07 cm{sup 2} and d = 0.03 {+-} 0.14 cm{sup 2}, respectively. Conclusion: CMR planimetry of the AVA is a noninvasive and reproducible technique to evaluate stenotic aortic valves and can be used as an alternative to echocardiography or cardiac catheterisation.

  8. Diagnostic performance of cardiac imaging methods to diagnose ischaemia-causing coronary artery disease when directly compared with fractional flow reserve as a reference standard

    DEFF Research Database (Denmark)

    Danad, Ibrahim; Szymonifka, Jackie; Twisk, Jos W R

    2016-01-01

    ), and cardiac magnetic resonance (MRI) imaging when directly compared with an FFR reference standard. METHOD AND RESULTS: PubMed and Web of Knowledge were searched for investigations published between 1 January 2002 and 28 February 2015. Studies performing FFR in at least 75% of coronary vessels......AIMS: The aim of this study was to determine the diagnostic performance of single-photon emission computed tomography (SPECT), stress echocardiography (SE), invasive coronary angiography (ICA), coronary computed tomography angiography (CCTA), fractional flow reserve (FFR) derived from CCTA (FFRCT...... for the diagnosis of ischaemic coronary artery disease (CAD) were included. Twenty-three articles reporting on 3788 patients and 5323 vessels were identified. Meta-analysis was performed for pooled sensitivity, specificity, likelihood ratios (LR), diagnostic odds ratio, and summary receiver operating characteristic...

  9. High-Throughput Assessment of Drug Cardiac Safety Using a High-Speed Impedance Detection Technology-Based Heart-on-a-Chip

    Directory of Open Access Journals (Sweden)

    Xi Zhang

    2016-07-01

    Full Text Available Drug cardiac safety assessments play a significant role in drug discovery. Drug-induced cardiotoxicity is one of the main reasons for drug attrition, even when antiarrhythmic drugs can otherwise effectively treat the arrhythmias. Consequently, efficient drug preclinical assessments are needed in the drug industry. However, most drug efficacy assessments are performed based on electrophysiological tests of cardiomyocytes in vitro and cannot effectively provide information on drug-induced dysfunction of cardiomyocyte beating. Here we present a heart-on-a-chip device for evaluating the drug cardiac efficacy using a high-speed impedance detection technology. Verapamil and doxorubicin were utilized to test this heart-on-a-chip, and multiple parameters of cardiomyocyte beating status are used to reveal the effects of drugs. The results show that drug efficacy or cardiotoxicity can be determined by this heart-on-a-chip. We believe this heart-on-a-chip will be a promising tool for the preclinical assessment of drug cardiac efficacy.

  10. China Patient-centered Evaluative Assessment of Cardiac Events Prospective Study of Acute Myocardial Infarction:Study Design

    Institute of Scientific and Technical Information of China (English)

    Jing Li; Rachel P Dreyer; Xi Li; Xue Du; Nicholas S Downing; Li Li; Hai-Bo Zhang

    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.

  11. Assessment of microembolization associated with revascularization in acute myocardial infarction: MDCT cardiac perfusion and function study.

    Science.gov (United States)

    Saeed, Maythem; Hetts, Steven W; Do, Loi; Wilson, Mark W

    2013-12-01

    To use multi-detector computed tomography (MDCT) for assessing the effects of coronary microemboli on pre-existing acute myocardial infarct (AMI) and to compare this pathology to LAD microembolization and occlusion/reperfusion. An angioplasty balloon catheter was placed in the LAD coronary artery of pigs under X-ray guidance. Four animals served as controls without intervention (group A) and an additional 24 animals (8/group) were subjected to microembolization (group B), occlusion/reperfusion (group C) or combination of the two insults (group D). MDCT was used to assess perfusion, LV function and viability. At postmortem, the LV sections were stained with hematoxylin/eosin and triphenyltetrazolium chloride (TTC). Dynamic perfusion and helical cine MDCT demonstrated decline in regional LV perfusion and function, respectively, after all interventions. MDCT showed significant differences in ejection fraction between groups: A = 57.5 ± 4.7%, B = 40.3 ± 0.5% P 0.7). Microscopic examination confirmed the presence of patchy and contiguous necrosis, MVO, edema and calcium deposits. Dynamic and helical cine MDCT imaging can grade LV dysfunction and perfusion deficit, respectively. DE-MDCT demonstrated a large and persistent MVO zone after microembolization of pre-existing AMI. Furthermore, it has the potential to visualize patchy microinfarct, detect perfusion deficits and dysfunction at the border zone after microembolization of pre-existing AMI.

  12. DOWNFLOW code and LIDAR technology for lava flow analysis and hazard assessment at Mount Etna

    OpenAIRE

    Alessandro Fornaciai; Simone Tarquini; Massimiliano Favalli

    2011-01-01

    The use of a lava-flow simulation (DOWNFLOW) probabilistic code and airborne light detection and ranging (LIDAR) technology are combined to analyze the emplacement of compound lava flow fields at Mount Etna (Sicily, Italy). The goal was to assess the hazard posed by lava flows. The LIDAR-derived time series acquired during the 2006 Mount Etna eruption records the changing topography of an active lava-flow field. These short-time-interval, high-resolution topographic surveys provide a detailed...

  13. [Fractional flow reserve and instantaneous wave-free ratio for the physiological assessment of coronary artery stenosis in the catheterization laboratory: Practical tips].

    Science.gov (United States)

    Picard, F; Tadros, V X; Pighi, M; Spagnoli, V; De Hemptinne, Q; Ly, H Q

    2017-02-01

    In recent years, a large body of evidence has revealed the limitations of angiographic evaluation in determining the physiological significance of coronary stenosis, particularly when these are intermediate lesions. Percutaneous coronary interventions (PCI) guided by physiological assessment using fractional flow reserve (FFR) have been shown to reduce cardiovascular events when compared to angiography alone. Recently, another coronary physiologic parameter has been introduced: the "instantaneous wave-free ratio" (iFR). In this review, we will discuss the FFR, the iFR, and their use in the functional assessment of coronary stenosis in the cardiac catheterization laboratory. This review will cover theoretical aspects for non-interventional cardiologists, as well as practice points and common pitfalls related to coronary physiological assessment for interventional cardiologists.

  14. Assessment of cerebellar pulsation in dogs with and without Chiari-like malformation and syringomyelia using cardiac-gated cine magnetic resonance imaging.

    Science.gov (United States)

    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.

  15. Use of I-123 MIBG cardiac scintigraphy to assess the impact of carvedilol on cardiac adrenergic neuronal function in childhood dilated cardiomyopathy; Interet de la scintigraphie cardiaque a l'I-123 MIBG pour evaluer l'impact du carvedilol sur la fonction neuronale adrenergique cardiaque dans les myocardiopathies dilatees de l'enfant

    Energy Technology Data Exchange (ETDEWEB)

    Maunoury, C. [Hopital Europeen Georges Pompidou (HEGP), Dept. de Physiologie et Radio-Isotopes, 75 - Paris (France); Acar, P. [Centre Hospitalier Universitaire, Service de Cardiologie Pediatrique, Hopital des Enfants, 31 - Toulouse (France); Sidi, D. [Centre Hospitalier Universitaire Necker-Enfants-Malades, 75 - Paris (France)

    2006-04-15

    I-123 MIBG cardiac scintigraphy is a useful tool to assess cardiac adrenergic neuronal function, which is impaired in children with dilated cardiomyopathy (DCM). In adults with DCM, long-term treatment with carvedilol improves both cardiac adrenergic neuronal function and left ventricular function. The aim of this prospective study was to evaluate the impact of carvedilol on cardiac adrenergic neuronal function and on left ventricular function in seventeen patients (11 female, 6 male, mean age 39 {+-} 57 months, range 1 - 168 months) with DCM. All patients underwent I-123 MIBG cardiac scintigraphy and equilibrium radio-nuclide angiography before and after a 6 month period of carvedilol therapy. A static anterior view of the chest was acquired 4 hours after intravenous injection of 20 to 75 MBq of I-123 MIBG. Cardiac neuronal uptake of I-123 MIBG was measured using the heart to mediastinum count ratio (HMR). Radionuclide left ventricular ejection fraction (LVEF) was assessed following a standard protocol. There was no major cardiac events (death or transplantation) during the follow-up period. I-123 MIBG cardiac uptake and left ventricular function respectively increased by 38% and 65% after 6 months of treatment with carvedilol (HMR 223 {+-} 49% vs 162 {+-} 26%, p < 0.0001 and LVEF = 43 {+-} 17% vs 26 {+-} 11%, p < 0.0001). Carvedilol can improve cardiac adrenergic neuronal function and left ventricular function in children with DCM. Further studies are needed to assess the relationship between improvement in I-123 MIBG cardiac uptake and the beneficial effects of carvedilol on morbidity and mortality. (authors)

  16. Assessment of flow distribution in the mouse fetal circulation at late gestation by high-frequency Doppler ultrasound.

    Science.gov (United States)

    Zhou, Yu-Qing; Cahill, Lindsay S; Wong, Michael D; Seed, Mike; Macgowan, Christopher K; Sled, John G

    2014-08-15

    This study used high-frequency ultrasound to evaluate the flow distribution in the mouse fetal circulation at late gestation. We studied 12 fetuses (embryonic day 17.5) from 12 pregnant CD1 mice with 40 MHz ultrasound to assess the flow in 11 vessels based on Doppler measurements of blood velocity and M-mode measurements of diameter. Specifically, the intrahepatic umbilical vein (UVIH), ductus venosus (DV), foramen ovale (FO), ascending aorta (AA), main pulmonary artery (MPA), ductus arteriosus (DA), descending thoracic aorta (DTA), common carotid artery (CCA), inferior vena cava (IVC), and right and left superior vena cavae (RSVC, LSVC) were examined, and anatomically confirmed by micro-CT. The mouse fetal circulatory system was found to be similar to that of the humans in terms of the major circuit and three shunts, but characterized by bilateral superior vena cavae and a single umbilical artery. The combined cardiac output (CCO) was 1.22 ± 0.05 ml/min, with the left ventricle (flow in AA) contributing 47.8 ± 2.3% and the right ventricle (flow in MPA) 52.2 ± 2.3%. Relative to the CCO, the flow percentages were 13.6 ± 1.0% for the UVIH, 10.4 ± 1.1% for the DV, 35.6 ± 2.4% for the DA, 41.9 ± 2.6% for the DTA, 3.8 ± 0.3% for the CCA, 29.5 ± 2.2% for the IVC, 12.7 ± 1.0% for the RSVC, and 9.9 ± 0.9% for the LSVC. The calculated flow percentage was 16.6 ± 3.4% for the pulmonary circulation and 31.2 ± 5.3% for the FO. In conclusion, the flow in mouse fetal circulation can be comprehensively evaluated with ultrasound. The baseline data of the flow distribution in normal mouse fetus serve as the reference range for future studies.

  17. Development of the Assessment Items of Debris Flow Using the Delphi Method

    Science.gov (United States)

    Byun, Yosep; Seong, Joohyun; Kim, Mingi; Park, Kyunghan; Yoon, Hyungkoo

    2016-04-01

    In recent years in Korea, Typhoon and the localized extreme rainfall caused by the abnormal climate has increased. Accordingly, debris flow is becoming one of the most dangerous natural disaster. This study aimed to develop the assessment items which can be used for conducting damage investigation of debris flow. Delphi method was applied to classify the realms of assessment items. As a result, 29 assessment items which can be classified into 6 groups were determined.

  18. Assessments of Coronary Artery Visibility and Radiation Dose in Infants with Congenital Heart Disease on Cardiac 128-slice CT and on Cardiac 64-slice CT.

    Science.gov (United States)

    Cui, Y; Huang, M; Zheng, J; Li, J; Liu, H; Liang, C

    2016-01-01

    The aim of this study was to compare the coronary artery visibility and radiation dose in infants with CHD on cardiac 128-slice CT and on cardiac 64-slice CT. The images of 200 patients were analyzed in this study, 100 patients were selected randomly from a group of 789 infants (coronary artery segments was graded on a four-point scale. The coronary arteries were considered to be detected or visible when grade was 2 or higher. The visibility of the coronary artery segments and the radiation dose was compared between the two groups. Except for the rate of LM (96 vs. 99%), the detection rates of the total, LAD, LCX, RCA, and the proximal segment of the RCA in the 256-slice CT group were significantly higher than those in the 64-slice CT group (51.7, 53.33, 33.67, 53.33, and 99 vs. 34.8, 34.33, 18, 30.67, and 75%, respectively). The counts of visibility score (4/3/2/1) for the LM and the proximal segment of the RCA were 62/22/12/4 and 56/20/17/7, respectively, in the 128-slice CT group and 17/42/30/1 and 9/30/38/25, respectively, in the 64-slice CT group. There were significant differences, especially for score 4 and 3, between the two groups. The radiation dose in the 128-slice CT group was significantly decreased than those in the 64-slice CT group (CTDIvol 1.88 ± 0.51 vs. 5.61 ± 0.63 mGy; SSDE 4.48 ± 1.15 vs. 13.97 ± 1.52 mGy; effective radiation dose 1.36 ± 0.44 vs. 4.06 ± 0.7 mSv). With reduced radiation dose, the visibility of the coronary artery in infants with CHD via prospective ECG-triggered mode on a 128-slice CT is superior to that of the 64-slice CT using retrospective ECG-gated spiral mode.

  19. Assessing Cardiac Injury in Mice With Dual Energy-MicroCT, 4D-MicroCT, and MicroSPECT Imaging After Partial Heart Irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Chang-Lung; Min, Hooney [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States); Befera, Nicholas; Clark, Darin; Qi, Yi [Center for In Vivo Microscopy, Department of Radiology, Duke University Medical Center, Durham, North Carolina (United States); Das, Shiva [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States); Johnson, G. Allan; Badea, Cristian T. [Center for In Vivo Microscopy, Department of Radiology, Duke University Medical Center, Durham, North Carolina (United States); Kirsch, David G., E-mail: david.kirsch@duke.edu [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States); Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, North Carolina (United States)

    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

  20. Debris flow hazard assessment for the Oregon Caves National Monument

    Science.gov (United States)

    Friday, John

    1983-01-01

    After experiencing a devastating debris flow in the Oregon Caves National Monument, the National Park Service needs an evaluation of the hazard of additional flows. Soil properties at six random sites were compared with those at the source of the debris flow. Although all sites had soils that could become unstable with sufficient moisture, soil at one site had properties similar to those at the scar and the potential for another flow was confirmed. The report suggests that winter weather conditions be closely monitored and compared to the antecedent conditions prior to the known failure. When the threshold for additional mass wasting is believed imminent, appropriate action can be taken to insure the safety of work personnel and the public. The peak streamflow that preceded the 5,200 cu yds of debris is estimated to have a 0.5 percent chance of being equaled or exceeded in any given year. (USGS)

  1. Radiation dose assessment in a 320-detector-row CT scanner used in cardiac imaging

    Energy Technology Data Exchange (ETDEWEB)

    Goma, Carles; Ruiz, Agustin; Jornet, Nuria; Latorre, Artur; Pallerol, Rosa M.; Carrasco, Pablo; Eudaldo, Teresa; Ribas, Montserrat [Servei de Radiofisica i Radioproteccio, Hospital de la Santa Creu i Sant Pau, Sant Antoni Maria Claret 167, 08025 Barcelona (Spain)

    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

  2. Use of cardiac biomarkers in neonatology.

    Science.gov (United States)

    Vijlbrief, Daniel C; Benders, Manon J N L; Kemperman, Hans; van Bel, Frank; de Vries, Willem B

    2012-10-01

    Cardiac biomarkers are used to identify cardiac disease in term and preterm infants. This review discusses the roles of natriuretic peptides and cardiac troponins. Natriuretic peptide levels are elevated during atrial strain (atrial natriuretic peptide (ANP)) or ventricular strain (B-type natriuretic peptide (BNP)). These markers correspond well with cardiac function and can be used to identify cardiac disease. Cardiac troponins are used to assess cardiomyocyte compromise. Affected cardiomyocytes release troponin into the bloodstream, resulting in elevated levels of cardiac troponin. Cardiac biomarkers are being increasingly incorporated into clinical trials as indicators of myocardial strain. Furthermore, cardiac biomarkers can possibly be used to guide therapy and improve outcome. Natriuretic peptides and cardiac troponins are potential tools in the diagnosis and treatment of neonatal disease that is complicated by circulatory compromise. However, clear reference ranges need to be set and validation needs to be carried out in a population of interest.

  3. Evaluation of cardiac blood blow, metabolism and sympathetic nerve function in patients with cardiac failure using PET and SPECT. Prognostic diagnosis based on the analysis of aggravating factors of the disease

    Energy Technology Data Exchange (ETDEWEB)

    Ishida, Yoshio; Shimozu, Junko; Yasumura, Yoshio; Nagatani, Kenzo; Miyatake, Kunio [National Cardiovascular Center, Suita, Osaka (Japan)

    1998-02-01

    Focusing on the failure of energy metabolism, which is assumed to be attributed to the cardiac muscle disorder of a patient with cardiac failure, the characteristics and diagnostic significance of the metabolic disorders of cadiac muscles were investigated in those patients. The diagnostic efficacy of {beta}-methyl iodophenyl pentadecanoic acid (BMIPP) which is a imaging agent for lipid metabolism in the cardiac muscle was assessed in the clinical states of cardiac failure due to pulmonary hypertension. Even if there was a considerable increase in the mean pulmonary arterial pressure (mPAP), the initial accumulation of BMIPP linearly increased, similarly to the increase in the accumulation of MIBI, a blood flow agent. The initial accumulation of BMIPP was thought to reflect a thicken cardiac muscle and/or increased blood flow. Also, its washing-out rate was suggested to be usable as an clinical indicator to estimate the loading of ventricular pressure. (M.N.)

  4. Transcranial Doppler Blood Flow Assessment in Patients With Mild Heart Failure: Correlates With Neuroimaging and Cognitive Performance

    NARCIS (Netherlands)

    Vogels, R.L.C.; Oosterman, J.M.; Laman, D.M.; Gouw, A.A.; Schroeder-Tanka, J.M.; Scheltens, P.; Flier, W.M. van der; Weinstein, H.C.

    2008-01-01

    Cardiac output and cerebral perfusion are reduced in patients with advanced stages of heart failure. Our aim was to determine whether cerebral blood flow velocity measured by transcranial Doppler ultrasonography was reduced in outpatients with mild heart failure in comparison to controls and, if so,

  5. Rubidium-82 PET-CT for quantitative assessment of myocardial blood flow: validation in a canine model of coronary artery stenosis

    Energy Technology Data Exchange (ETDEWEB)

    Lautamaeki, Riikka; Higuchi, Takahiro; Merrill, Jennifer; Voicu, Corina; Bengel, Frank M. [Johns Hopkins Medical Institutions, Department of Radiology, Division of Nuclear Medicine, Baltimore, MD (United States); George, Richard T.; Kitagawa, Kakuya; DiPaula, Anthony; Lima, Joao A.C. [Johns Hopkins Medical Institutions, Department of Medicine, Division of Cardiology, Baltimore, MD (United States); Nekolla, Stephan G. [Technischen Universitaet Muenchen, Nuklearmedizinische Klinik und Poliklinik, Klinikum rechts der Isar, Munich (Germany); Lardo, Albert C. [Johns Hopkins Medical Institutions, Department of Medicine, Division of Cardiology, Baltimore, MD (United States); Johns Hopkins Medical Institutions, Department of Biomedical Engineering, Baltimore, MD (United States)

    2009-04-15

    Absolute quantification of myocardial blood flow expands the diagnostic potential of PET for assessment of coronary artery disease. {sup 82}Rb has significantly contributed to increasing utilization of PET; however, clinical studies are still mostly analysed qualitatively. The aim of this study was to reevaluate the feasibility of {sup 82}Rb for flow quantification, using hybrid PET-CT in an animal model of coronary stenosis. Nine dogs were prepared with experimental coronary artery stenosis. Dynamic PET was performed for 8 min after {sup 82}Rb(1480-1850 MBq) injection during adenosine-induced vasodilation. Microspheres were injected simultaneously for reference flow measurements. CT angiography was used to determine the myocardial regions related to the stenotic vessel. Two methods for flow calculation were employed: a two-compartment model including a spill-over term, and a simplified retention index. The two-compartment model data were in good agreement with microsphere flow (y=0.84x+0.20; r=0.92, p<0.0001), although there was variability in the physiological flow range <3 ml/g per minute (y=0.54x+0.53; r=0.53, p=0.042). Results from the retention index also correlated well with microsphere flow (y=0.47x+0.52; r=0.75, p=0.0004). Error increased with higher flow, but the correlation was good in the physiological range (y=0.62x+0.29; r=0.84, p=0.0001). Using current state-of-the-art PET-CT systems, quantification of myocardial blood flow is feasible with {sup 82}Rb. A simplified approach based on tracer retention is practicable in the physiological flow range. These results encourage further testing of the robustness and usefulness in the clinical context of cardiac hybrid imaging. (orig.)

  6. Cardiac Sarcoidosis.

    Science.gov (United States)

    Birnie, David; Ha, Andrew C T; Gula, Lorne J; Chakrabarti, Santabhanu; Beanlands, Rob S B; Nery, Pablo

    2015-12-01

    Studies suggest clinically manifest cardiac involvement occurs in 5% of patients with pulmonary/systemic sarcoidosis. The principal manifestations of cardiac sarcoidosis (CS) are conduction abnormalities, ventricular arrhythmias, and heart failure. Data indicate that an 20% to 25% of patients with pulmonary/systemic sarcoidosis have asymptomatic (clinically silent) cardiac involvement. An international guideline for the diagnosis and management of CS recommends that patients be screened for cardiac involvement. Most studies suggest a benign prognosis for patients with clinically silent CS. Immunosuppression therapy is advocated for clinically manifest CS. Device therapy, with implantable cardioverter defibrillators, is recommended for some patients.

  7. Anti-addiction drug ibogaine inhibits voltage-gated ionic currents: A study to assess the drug's cardiac ion channel profile

    Energy Technology Data Exchange (ETDEWEB)

    Koenig, Xaver; Kovar, Michael; Rubi, Lena; Mike, Agnes K.; Lukacs, Peter; Gawali, Vaibhavkumar S.; Todt, Hannes [Center for Physiology and Pharmacology, Department of Neurophysiology and -pharmacology, Medical University of Vienna, 1090 Vienna (Austria); Hilber, Karlheinz, E-mail: karlheinz.hilber@meduniwien.ac.at [Center for Physiology and Pharmacology, Department of Neurophysiology and -pharmacology, Medical University of Vienna, 1090 Vienna (Austria); Sandtner, Walter [Center for Physiology and Pharmacology, Institute of Pharmacology, Medical University of Vienna, 1090 Vienna (Austria)

    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

  8. Bridging Minds: A Mixed Methodology to Assess Networked Flow.

    Science.gov (United States)

    Galimberti, Carlo; Chirico, Alice; Brivio, Eleonora; Mazzoni, Elvis; Riva, Giuseppe; Milani, Luca; Gaggioli, Andrea

    2015-01-01

    The main goal of this contribution is to present a methodological framework to study Networked Flow, a bio-psycho-social theory of collective creativity applying it on creative processes occurring via a computer network. First, we draw on the definition of Networked Flow to identify the key methodological requirements of this model. Next, we present the rationale of a mixed methodology, which aims at combining qualitative, quantitative and structural analysis of group dynamics to obtain a rich longitudinal dataset. We argue that this integrated strategy holds potential for describing the complex dynamics of creative collaboration, by linking the experiential features of collaborative experience (flow, social presence), with the structural features of collaboration dynamics (network indexes) and the collaboration outcome (the creative product). Finally, we report on our experience with using this methodology in blended collaboration settings (including both face-to-face and virtual meetings), to identify open issues and provide future research directions.

  9. Assessment of subchannel code ASSERT-PV for flow-distribution predictions

    Energy Technology Data Exchange (ETDEWEB)

    Nava-Dominguez, A., E-mail: navadoma@aecl.ca; Rao, Y.F., E-mail: raoy@aecl.ca; Waddington, G.M., E-mail: waddingg@aecl.ca

    2014-08-15

    Highlights: • Assessment of the subchannel code ASSERT-PV 3.2 for the prediction of flow distribution. • Open literature and in-house experimental data to quantify ASSERT-PV predictions. • Model changes assessed against vertical and horizontal flow experiments. • Improvement of flow-distribution predictions under CANDU-relevant conditions. - Abstract: This paper reports an assessment of the recently released subchannel code ASSERT-PV 3.2 for the prediction of flow-distribution in fuel bundles, including subchannel void fraction, quality and mass fluxes. Experimental data from open literature and from in-house tests are used to assess the flow-distribution models in ASSERT-PV 3.2. The prediction statistics using the recommended model set of ASSERT-PV 3.2 are compared to those from previous code versions. Separate-effects sensitivity studies are performed to quantify the contribution of each flow-distribution model change or enhancement to the improvement in flow-distribution prediction. The assessment demonstrates significant improvement in the prediction of flow-distribution in horizontal fuel channels containing CANDU bundles.

  10. Benchmarking Computational Fluid Dynamics Models for Application to Lava Flow Simulations and Hazard Assessment

    Science.gov (United States)

    Dietterich, H. R.; Lev, E.; Chen, J.; Cashman, K. V.; Honor, C.

    2015-12-01

    Recent eruptions in Hawai'i, Iceland, and Cape Verde highlight the need for improved lava flow models for forecasting and hazard assessment. Existing models used for lava flow simulation range in assumptions, complexity, and the degree to which they have been validated against analytical solutions, experiments, and natural observations. In order to assess the capabilities of existing models and test the development of new codes, we conduct a benchmarking study of computational fluid dynamics models for lava flows, including VolcFlow, OpenFOAM, Flow3D, and COMSOL. Using new benchmark scenarios defined in Cordonnier et al. (2015) as a guide, we model Newtonian, Herschel-Bulkley and cooling flows over inclined planes, obstacles, and digital elevation models with a wide range of source conditions. Results are compared to analytical theory, analogue and molten basalt experiments, and measurements from natural lava flows. Our study highlights the strengths and weakness of each code, including accuracy and computational costs, and provides insights regarding code selection. We apply the best-fit codes to simulate the lava flows in Harrat Rahat, a predominately mafic volcanic field in Saudi Arabia. Input parameters are assembled from rheology and volume measurements of past flows using geochemistry, crystallinity, and present-day lidar and photogrammetric digital elevation models. With these data, we use our verified models to reconstruct historic and prehistoric events, in order to assess the hazards posed by lava flows for Harrat Rahat.

  11. Regional myocardial blood flow, metabolism and function assessed noninvasively by positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Schelbert, H.R.; Phelps, M.E.; Hoffman, E.; Huang, S.; Kuhl, D.E.

    1979-01-01

    Positron emission computed tomography is a new technique for the noninvasive measure of myocardial blood flow, mechanical function and, in particular, metabolism. The capability of this new study means is due to the technological innovations of the imaging device and the availability of radioactive tracers that are specific for blood flow and metabolism. The device permits recording of cross-sectional images of the left ventricular myocardium that reflect quantitatively regional tracer tissue concentrations. By employing tracer kinetic models this new technique permits the measurement of regional glucose and fatty acid metabolism of the heart. While already an important new tool for investigative studies into cardiac physiology and pathophysiology, the clinical utility of positron emission tomography remains to be defined.

  12. Correlation of 64 row MDCT, echocardiography and cardiac catheterization angiography in assessment of pulmonary arterial anatomy in children with cyanotic congenital heart disease

    Energy Technology Data Exchange (ETDEWEB)

    Chandrashekhar, Guruprasadh, E-mail: cguruprasadh@gmail.com [Departments of Radiodiagnosis and Imaging, Post Graduate Institute of Medical Education and Research, Sector-12, Chandigarh 160012 (India); Sodhi, Kushaljit Singh, E-mail: sodhiks@gmail.com [Departments of Radiodiagnosis and Imaging, Post Graduate Institute of Medical Education and Research, Sector-12, Chandigarh 160012 (India); Saxena, Akshay Kumar, E-mail: fatakshay@yahoo.com [Departments of Radiodiagnosis and Imaging, Post Graduate Institute of Medical Education and Research, Sector-12, Chandigarh 160012 (India); Rohit, Manoj Kumar, E-mail: rohitmanoj@gmail.com [Department of Pediatric Cardiology, Post Graduate Institute of Medical Education and Research, Sector-12, Chandigarh 160012 (India); Khandelwal, Niranjan, E-mail: khandelwaln@hotmail.com [Departments of Radiodiagnosis and Imaging, Post Graduate Institute of Medical Education and Research, Sector-12, Chandigarh 160012 (India)

    2012-12-15

    Objective: To study the correlation of low-dose 64-row multi-detector computed tomography (MDCT) with echocardiography and cardiac catheterization angiography (CCA) in the assessment of pulmonary arterial anatomy in children with cyanotic congenital heart disease (CCHD). Materials and methods: This prospective study included 105 children (74 males, 31 females) with CCHD, in the age group of 2 months to 20 years, who underwent 64-row MDCT examination (low-dose CT protocol), echocardiography and CCA for the assessment of pulmonary arteries, including visualization, presence of confluence, stenosis and collaterals. Statistical analysis was performed using the non-parametric statistical analysis test to evaluate the concordance or discordance between echocardiography, MDCT and CCA. Results: 64-row MDCT detected significantly more main and branch pulmonary arteries, patent pulmonary confluences, and more cases of pulmonary artery stenosis. CCA detected more major aorto-pulmonary collaterals than MDCT, whereas echocardiography failed to identify these major aorto-pulmonary collaterals. The effective CT radiation dose to patients less than 2 years of age was in the range of 0.7–2.5 mSv, where as the dose in patients more than 2 years of age ranged from that of 2.1 to 4.2 mSv, which is much less than the radiation dose reported in cardiac catheterization angiography. Conclusion: In cases where cardiac MRI cannot be performed, or is not sufficiently informative, low-dose 64-row MDCT correlates well with CCA and can provide adequate information about pulmonary arterial anatomy in children with cyanotic congenital heart disease, and can replace invasive cardiac catheterization angiography with markedly reduced radiation dosage to the patient.

  13. Assessment of a peak flow whistle in nonasthmatic children.

    Science.gov (United States)

    Terblanche, E; Fourie, P R; Wessels, J A

    1999-06-01

    We tested the agreement of peak expiratory flow (PEF) measurements between an electronic spirometer and a peak flow whistle (Whistle Watch, HarMed, Capetown, South Africa). One hundred and three healthy children between ages 6-13 years and with no previous experience in lung function tests participated in the study. Sequential PEF-readings were obtained from the spirometer and the peak flow whistle; all children had an equal number of attempts using both devices. In the case of the spirometer, the highest PEF reading of three acceptable and reproducible efforts was noted as the best PEF (PEF(SPIRO)). Whistle Watch readings were taken as the highest value when the child could activate the whistle. Despite a strong correlation (r = 0.91; R2 = 83%) between the readings of the spirometer and Whistle Watch, there was a lack of agreement between the two devices. For any individual subject, the 95% probability interval ranged between +30.4 to -47 L.min(-1); 64% of the children obtained higher PEF-values on Whistle Watch, compared to the spirometer. These findings suggest that the whistle sound of the peak flow whistle was a significant incentive, which resulted in greater maximal expiratory efforts.

  14. Assessment of environmental flow requirement effects at an estuary

    NARCIS (Netherlands)

    Fatemi, Seyed Ehsan; Vafaie, Freydon; Bressers, Hans

    2013-01-01

    This paper describes the application of dynamic system modelling to investigate the consequences for water supply of maintaining environmental flow requirements in the Gorganrud River Basin in Iran. In this study the output results of Vensim and Weap models were compared and found to match each othe

  15. Coronary Flow Velocity Reserve Assessed by Transthoracic Doppler

    DEFF Research Database (Denmark)

    Michelsen, Marie M; Pena, Adam; Mygind, Naja D;

    2016-01-01

    of the left anterior descending coronary artery in two-dimensional color Doppler mode, and (4) gradual, consistent increases of characteristic, well-defined flow velocity curves in pulsed-wave mode. RESULTS: The mean age (SD) was 62.1 ± 9.7 years. On the basis of the evaluations, patients were divided...

  16. Assessment of salivary flow rate: biologic variation and measure error.

    NARCIS (Netherlands)

    Jongerius, P.H.; Limbeek, J. van; Rotteveel, J.J.

    2004-01-01

    OBJECTIVE: To investigate the applicability of the swab method in the measurement of salivary flow rate in multiple-handicap drooling children. To quantify the measurement error of the procedure and the biologic variation in the population. STUDY DESIGN: Cohort study. METHODS: In a repeated measurem

  17. Accounting for environmental flow requirements in global water assessments

    NARCIS (Netherlands)

    Pastor, A.V.; Ludwig, F.; Biemans, H.; Hoff, H.; Kabat, P.

    2013-01-01

    With growing water needs for food production, it is necessary to improve the quantification of "Environmental Flow Requirements (EFRs)" to secure enough water for the freshwater ecosystems. In this study, five methods for calculating EFRs were compared to 11 case studies of locally-calculated EFRs.

  18. Effects of feeding and hypoxia on cardiac performance and gastrointestinal blood flow during critical speed swimming in the sea bass Dicentrarchus labrax.

    Science.gov (United States)

    Dupont-Prinet, A; Claireaux, G; McKenzie, D J

    2009-10-01

    Previous studies have shown that if European sea bass are exercised after feeding, they can achieve a significantly higher maximum metabolic rate (MMR) than when fasted. They can meet combined metabolic demands of digestion (specific dynamic action, SDA) and maximal aerobic exercise, with no decline in swimming performance. If, however, exposed to mild hypoxia (50% saturation), bass no longer achieve higher MMR after feeding but they swim as well fed as fasted, due to an apparent ability to defer the SDA response. This study explored patterns of cardiac output (Q(A)) and blood flow to the gastrointestinal tract (Q(GI)) associated with the higher MMR after feeding, and with the ability to prioritise swimming in hypoxia. Sea bass (mean mass approximately 325 g, forklength approximately 27 cm) were instrumented with flow probes to measure Q(A) and Q(GI) during an incremental critical swimming speed (U(crit)) protocol in a tunnel respirometer, to compare each animal either fasted or 6h after a meal of fish fillet equal to 3% body mass. Feeding raised oxygen uptake (M(O2)) prior to exercise, an SDA response associated with increased Q(A) (+30%) and Q(GI) (+100%) compared to fasted values. As expected, when exercised the fed bass maintained the SDA load throughout the protocol and achieved 14% higher MMR than when fasted, and the same U(crit) (approximately 100 cm s(-1)). Both fed and fasted bass showed pronounced increases in Q(A) and decreases in Q(GI) during exercise and the higher MMR of fed bass was not associated with higher maximum Q(A) relative to when fasted, or to any differences in Q(GI) at maximum Q(A). In hypoxia prior to exercise, metabolic and cardiac responses to feeding were similar compared to normoxia. Hypoxia caused an almost 60% reduction to MMR and 30% reduction to U(crit), but neither of these traits differed between fed or fasted bass. Despite hypoxic limitations to MMR and U(crit), maximum Q(A) and patterns of Q(GI) during exercise in fasted and

  19. Ventricular synchronicity: observations comparing pulse flow and tissue Doppler assessment in a Chinese healthy adult cohort

    Institute of Scientific and Technical Information of China (English)

    QUAN Xin; ZHU Tian-gang; GUO Shi; MA Jian-xin; WANG Xin; GUO Ji-hong

    2012-01-01

    Background Mechanical asynchrony is an important parameter in predicting the response to cardiac resynchronization therapy,but detailed knowledge about cardiac timing in healthy persons is scarce.Therefore,in the current study,we sought to investigate the physiological status of interventricular synchronicity using pulse wave flow and tissue Doppler imaging in a healthy Chinese population.Methods Eighty-eight healthy volunteers underwent standard flow and tissue Doppler echocardiographic examinations.Ventricular inflow and outflow pulse wave flow Doppler patterns were recorded together with annulus pulse tissue Doppler imaging.Time intervals from the beginning of the QRS complex to the onset,peak and end of each wave were measured.Results The onsets of systole between left and right ventricles were highly synchronized by both imaging modalities.However,the left ventricle reached the peak flow ejection and peak mechanical contraction earlier than the right ventricle,(165.61±26.23) ms vs.(204.3±34.55) ms (P <0.01) and (133.62±26.19) ms vs.(191.25±38.47) ms (P <0.01).Time to peak early diastolic relaxation was earlier in the left ventricle than in the right heart,(500.23±56.52) me vs.(524.94±47.42) ms (P <0.01).Conclusions Left and right ventricles were well synchronized at the onsets of systole and diastole even though interventricular peak systolic and peak early diastolic dyssynchrony was observed in healthy people by pulse wave Doppler imaging.In addition,diastolic timing events were slightly affected by age and gender.

  20. Cardiac tumors: optimal cardiac MR sequences and spectrum of imaging appearances.

    LENUS (Irish Health Repository)

    O'Donnell, David H

    2012-02-01

    OBJECTIVE: This article reviews the optimal cardiac MRI sequences for and the spectrum of imaging appearances of cardiac tumors. CONCLUSION: Recent technologic advances in cardiac MRI have resulted in the rapid acquisition of images of the heart with high spatial and temporal resolution and excellent myocardial tissue characterization. Cardiac MRI provides optimal assessment of the location, functional characteristics, and soft-tissue features of cardiac tumors, allowing accurate differentiation of benign and malignant lesions.

  1. Assessment of blood flow velocity and pulsatility in cerebral perforating arteries with 7-T quantitative flow MRI.

    Science.gov (United States)

    Bouvy, W H; Geurts, L J; Kuijf, H J; Luijten, P R; Kappelle, L J; Biessels, G J; Zwanenburg, J J M

    2016-09-01

    Thus far, blood flow velocity measurements with MRI have only been feasible in large cerebral blood vessels. High-field-strength MRI may now permit velocity measurements in much smaller arteries. The aim of this proof of principle study was to measure the blood flow velocity and pulsatility of cerebral perforating arteries with 7-T MRI. A two-dimensional (2D), single-slice quantitative flow (Qflow) sequence was used to measure blood flow velocities during the cardiac cycle in perforating arteries in the basal ganglia (BG) and semioval centre (CSO), from which a mean normalised pulsatility index (PI) per region was calculated (n = 6 human subjects, aged 23-29 years). The precision of the measurements was determined by repeated imaging and performance of a Bland-Altman analysis, and confounding effects of partial volume and noise on the measurements were simulated. The median number of arteries included was 14 in CSO and 19 in BG. In CSO, the average velocity per volunteer was in the range 0.5-1.0 cm/s and PI was 0.24-0.39. In BG, the average velocity was in the range 3.9-5.1 cm/s and PI was 0.51-0.62. Between repeated scans, the precision of the average, maximum and minimum velocity per vessel decreased with the size of the arteries, and was relatively low in CSO and BG compared with the M1 segment of the middle cerebral artery. The precision of PI per region was comparable with that of M1. The simulations proved that velocities can be measured in vessels with a diameter of more than 80 µm, but are underestimated as a result of partial volume effects, whilst pulsatility is overestimated. Blood flow velocity and pulsatility in cerebral perforating arteries have been measured directly in vivo for the first time, with moderate to good precision. This may be an interesting metric for the study of haemodynamic changes in aging and cerebral small vessel disease. © 2015 The Authors NMR in Biomedicine Published by John Wiley & Sons Ltd.

  2. Cardiac Malpositions

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Shi Joon; Im, Chung Gie; Yeon, Kyung Mo; Hasn, Man Chung [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    1979-06-15

    Cardiac Malposition refers to any position of the heart other than a left-sided heart in a situs solitus individual. Associated cardiac malformations are so complex that even angiocardiographic and autopsy studies may not afford an accurate information. Although the terms and classifications used to describe the internal cardiac anatomy and their arterial connections in cardiac malpositions differ and tend to be confusing, common agreement exists on the need for a segmental approach to diagnosis. Authors present 18 cases of cardiac malpositions in which cardiac catheterization and angiocardiography were done at the Department of Radiology, Seoul National University Hospital between 1971 and 1979. Authors analyzed the clinical, radiographic, operative and autopsy findings with the emphasis on the angiocardiographic findings. The results are as follows: 1. Among 18 cases with cardiac malpositions, 6 cases had dextrocardia with situs inversus, 9 cases had dextrocardia with situs solitus and 3 cases had levocardia with situs inversus. 2. There was no genuine exception to visceroatrial concordance rule. 3. Associated cardiac malpositions were variable and complex with a tendency of high association of transposition and double outlet varieties with dextrocardia in situs solitus and levocardia in situs inversus. Only one in 6 cases of dextrocardia with situs inversus had pure transposition. 4. In two cases associated pulmonary atresia was found at surgery which was not predicted by angiocardiography. 5. Because many of the associated complex lesions can be corrected surgically provided the diagnosis is accurate, the selective biplane angiocardiography with or without cineradiography is essential.

  3. The vulnerability assessment of rainfall-induced debris flows in Taiwan

    Science.gov (United States)

    Lu, George Yen-Hsu

    2007-12-01

    A debris flow vulnerability assessment which incorporates topographic and rainfall effects is developed. Rainfall at a scale compatible with the resolution of digital elevation model is obtained using a neural network estimation method with a wind induced topographic effect and rainfall derived from satellite rain estimates and an improved inverse distance weight method. The technique is tested using data collected during the passage of typhoon Tori-Ji on July 2001, which caused massive debris flows in central Taiwan. Numerous debris flows triggered by the typhoon were used as control for the study. The results show that the proposed wind-topography neural network (WTNN) technique outperforms other popular interpolation techniques, including inversed distance weight method (IDW), ordinary kriging (OK), co-kriging method, and multiple linear regression method. Multiple fuzzy-logic-based debris flow susceptibility factors are used to characterize watersheds. Self-organizing maps (SOM) was adopted for the debris flow vulnerability assessment by incorporating estimated rainfall and debris flow susceptibility factors. The result examined by contingency table agrees to the assessment proposed by Soil and Water Conservation Bureau of Taiwan and National Science and Technology Center for Hazard Reduction of Taiwan. An index of vulnerability representing the degrees of hazard is implemented in a GIS-based decision support system which decision maker can use to manage debris flow environmental issues. Key Words. Debris flow, spatial interpolation, vulnerability assessment, satellite rainfall, neural network, GIS.

  4. Regional cerebral blood flow assessed by 133Xe inhalation and emission tomography

    DEFF Research Database (Denmark)

    Shirahata, N; Henriksen, L; Vorstrup, S

    1985-01-01

    Regional cerebral blood flow (rCBF) in the cerebral hemispheres and the cerebellum was measured by single photon emission computed tomography with inhalation of 133Xe in 39 normal volunteers at test. The goal of this study was to assess the normal flow pattern and its variations. Five parallel...

  5. Necessity of angiotensin-converting enzyme-related gene for cardiac functions and longevity of Drosophila melanogaster assessed by optical coherence tomography

    Science.gov (United States)

    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.

  6. Use of an Implantable Loop Recorder in a Chimpanzee (Pan troglodytes) to Monitor Cardiac Arrhythmias and Assess the Effects of Acupuncture and Laser Therapy.

    Science.gov (United States)

    Magden, Elizabeth R; Sleeper, Meg M; Buchl, Stephanie J; Jones, Rebekah A; Thiele, Erica J; Wilkerson, Gregory K

    2016-02-01

    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.

  7. A new classifier-based strategy for in-silico ion-channel cardiac drug safety assessment

    Directory of Open Access Journals (Sweden)

    Hitesh eMistry

    2015-03-01

    Full Text Available There is currently a strong interest in using high-throughput in-vitro ion-channel screening data to make predictions regarding the cardiac toxicity potential of a new compound in both animal and human studies. A recent FDA think tank encourages the use of biophysical mathematical models of cardiac myocytes for this prediction task. However, it remains unclear whether this approach is the most appropriate. Here we examine five literature data-sets that have been used to support the use of four different biophysical models and one statistical model for predicting cardiac toxicity in numerous species using various endpoints. We propose a simple model that represents the balance between repolarisation and depolarisation forces and compare the predictive power of the model against the original results (leave-one-out cross-validation. Our model showed equivalent performance when compared to the four biophysical models and one statistical model. We therefore conclude that this approach should be further investigated in the context of early cardiac safety screening when in-vitro potency data is generated.

  8. Longer-Term Assessment of Trastuzumab-Related Cardiac Adverse Events in the Herceptin Adjuvant (HERA) Trial

    NARCIS (Netherlands)

    Procter, Marion; Suter, Thomas M.; de Azambuja, Evandro; Dafni, Urania; van Dooren, Veerle; Muehlbauer, Susanne; Climent, Miguel Angel; Rechberger, Ernst; Liu, Walter Tsang-Wu; Toi, Mazakasu; Coombes, R. Charles; Dodwell, David; Pagani, Olivia; Madrid, Jorge; Hall, Marcia; Chen, Shin-Cheh; Focan, Christian; Muschol, Michael; van Veldhuisen, Dirk J.; Piccart-Gebhart, Martine J.

    2010-01-01

    Purpose We investigated the incidence of cardiac adverse events in patients with early breast cancer in the Herceptin Adjuvant (HERA) trial who were treated with 1 year of trastuzumab after completion of (neo)adjuvant chemotherapy. Patients and Methods The HERA trial is a three-group, randomized tri

  9. A prospective study of paediatric cardiac surgical microsystems: assessing the relationships between non-routine events, teamwork and patient outcomes

    NARCIS (Netherlands)

    Schraagen, J.M.C.; Schouten, T.; Smit, M.; Haas, F.; Beek, D. van der; Ven, J. van der; Barach, P.

    2011-01-01

    Objective: Paediatric cardiac surgery has a low error tolerance and demands high levels of cognitive and technical performance. Growing evidence suggests that further improvements in patient outcomes depend on system factors, in particular, effective team skills. The hypotheses that small intraopera

  10. Tissue-Doppler assessment of cardiac left ventricular function during short-term adjuvant epirubicin therapy for breast cancer

    DEFF Research Database (Denmark)

    Appel, Jon M; Sogaard, Peter; Mortensen, Christiane E;

    2011-01-01

    It has been hypothesized that the extent of acute anthracycline-induced cardiotoxicity reflects the risk for late development of heart failure. The aim of this study was to examine if short-term changes in cardiac function can be detected even after low-dose adjuvant epirubicin therapy for breast...... cancer when using Doppler tissue imaging of longitudinal left ventricular function....

  11. Comprehensive cardiac rehabilitation

    DEFF Research Database (Denmark)

    Kruse, Marie; Hochstrasser, Stefan; Zwisler, Ann-Dorthe O;

    2006-01-01

    OBJECTIVES: The costs of comprehensive cardiac rehabilitation are established and compared to the corresponding costs of usual care. The effect on health-related quality of life is analyzed. METHODS: An unprecedented and very detailed cost assessment was carried out, as no guidelines existed...... for the situation at hand. Due to challenging circumstances, the cost assessment turned out to be ex-post and top-down. RESULTS: Cost per treatment sequence is estimated to be approximately euro 976, whereas the incremental cost (compared with usual care) is approximately euro 682. The cost estimate is uncertain...... and may be as high as euro 1.877. CONCLUSIONS: Comprehensive cardiac rehabilitation is more costly than usual care, and the higher costs are not outweighed by a quality of life gain. Comprehensive cardiac rehabilitation is, therefore, not cost-effective....

  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

    Directory of Open Access Journals (Sweden)

    Lewis JE

    2011-09-01

    Full Text Available John E Lewis1, Stacey L Tannenbaum1, Jinrun Gao3, Angelica B Melillo1, Evan G Long1, Yaima Alonso2, Janet Konefal1, Judi M Woolger2, Susanna Leonard1, Prabjot K Singh1, Lawrence Chen1, Eduard Tiozzo1 1Department of Psychiatry and Behavioral Sciences, 2Department of Medicine, University of Miami Miller School of Medicine, Miami, FL, 3State Farm Insurance, Bloomington, IL, USA 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

  13. Feasibility of automatic assessment of four-chamber cardiac function with MDCT: Initial clinical application and validation

    Energy Technology Data Exchange (ETDEWEB)

    Abadi, Sobhi [Radiology Department, Rambam Health Care Campus and Technion - Israel Institute of Technology, P.O.B. 9602, Haifa 31096 (Israel)], E-mail: s_abadi@rambam.health.gov.il; Roguin, Ariel [Cardiology Department, Rambam Health Care Campus and Technion - Israel Institute of Technology, P.O.B. 9602, Haifa 31096 (Israel); Engel, Ahuva [Radiology Department, Rambam Health Care Campus and Technion - Israel Institute of Technology, P.O.B. 9602, Haifa 31096 (Israel); Lessick, Jonathan [Cardiology Department, Rambam Health Care Campus and Technion - Israel Institute of Technology, P.O.B. 9602, Haifa 31096 (Israel)], E-mail: j_lessick@rambam.health.gov.il

    2010-04-15

    Background: The ability to perform a simultaneous analysis of ventricular and atrial volumes may provide clinically useful information for diagnosis and prognosis. We aimed to evaluate the feasibility and clinical value of a novel algorithm that performs fully automatic evaluation of the four cardiac chambers and myocardium from gated CT datasets. Methods: 50 patients were studied-Group 1: 30 consecutive unselected patients, Group 2A: 10 patients after myocardial infarction and Group 2B: 10 normal controls. Fully automatic, segmentation of the heart was performed with a model-based segmentation algorithm requiring no user input other than loading the datasets. Qualitative and quantitative evaluation of segmentation quality was performed. Left ventricular (LV) and right ventricular (RV) stroke volumes (SV) were compared. Results: Overall, segmentation succeeded in all patients although 11/500 (2.2%) cardiac chambers achieved poor segmentation grading. Correlation coefficients between automatic and manually derived volumes were excellent (r > 0.98) for all chambers. Bland-Altman analysis showed minimal bias (-1.0 ml, 0.4 ml, -1.8 ml) for the LV and RV, and right atria, respectively, with mild overestimation of LV myocardial volume (5.2 ml). Significant, yet consistent, overestimation of left atrial volume (23.6 ml) due to inclusion of proximal pulmonary veins was observed. LV and RV ejection fraction (r = 0.91 and 0.98) and SV (r = 0.98 and 0.99) also correlated closely with minimal bias (<2%). Most significantly, LV SV (91.0 {+-} 21.6 ml) correlated highly with RV SV (81.7 {+-} 18.2 ml, r = 0.86). Outliers could usually be explained by valvular regurgitation. Conclusions: Fully automatic segmentation of all cardiac chambers can be achieved with high accuracy over multiple cardiac phases, enabling reliable comprehensive evaluation of four-chamber cardiac function.

  14. Remote sensing of rainfall for debris-flow hazard assessment

    Science.gov (United States)

    Wieczorek, G.F.; Coe, J.A.; Godt, J.W.; ,

    2003-01-01

    Recent advances in remote sensing of rainfall provide more detailed temporal and spatial data on rainfall distribution. Four case studies of abundant debris flows over relatively small areas triggered during intense rainstorms are examined noting the potential for using remotely sensed rainfall data for landslide hazard analysis. Three examples with rainfall estimates from National Weather Service Doppler radar and one example with rainfall estimates from infrared imagery from a National Oceanic and Atmospheric Administration satellite are compared with ground-based measurements of rainfall and with landslide distribution. The advantages and limitations of using remote sensing of rainfall for landslide hazard analysis are discussed. ?? 2003 Millpress,.

  15. Feasibility of free-breathing, GRAPPA-based, real-time cardiac cine assessment of left-ventricular function in cardiovascular patients at 3 T

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Xiaomei, E-mail: xiaomeizhunanjing@163.com [Institute of Clinical Radiology, Ludwig-Maximilians-University Hospital, Marchioninistrasse 15, 81377 Munich (Germany); Department of Radiology, The First Affiliated Hospital of Nanjing Medical University, 300, Guangzhou Road, 210029 Nanjing, Jiangsu (China); Schwab, Felix, E-mail: flixschwab@googlemail.com [Institute of Clinical Radiology, Ludwig-Maximilians-University Hospital, Marchioninistrasse 15, 81377 Munich (Germany); Marcus, Roy, E-mail: Roy.Marcus@med.uni-muenchen.de [Institute of Clinical Radiology, Ludwig-Maximilians-University Hospital, Marchioninistrasse 15, 81377 Munich (Germany); Hetterich, Holger, E-mail: Holger.Hetterich@med.uni-muenchen.de [Institute of Clinical Radiology, Ludwig-Maximilians-University Hospital, Marchioninistrasse 15, 81377 Munich (Germany); Theisen, Daniel, E-mail: daniel.theisen@me.com [Institute of Clinical Radiology, Ludwig-Maximilians-University Hospital, Marchioninistrasse 15, 81377 Munich (Germany); Kramer, Harald, E-mail: Harald.Kramer@med.uni-muenchen.de [Institute of Clinical Radiology, Ludwig-Maximilians-University Hospital, Marchioninistrasse 15, 81377 Munich (Germany); Notohamiprodjo, Mike, E-mail: Mike.Notohamiprodjo@med.lmu.de [Department of Radiology, University of Tuebingen, Hoppe-Seyler-Str. 3, 72076 Tuebingen (Germany); Schlett, Christopher L., E-mail: Christopher.Schlett@med.uni-heidelberg.de [Department of Radiology, University of Heidelberg, Neuenheimer Feld 110, 69120 Heidelberg (Germany); Nikolaou, Konstantin, E-mail: Konstantin.Nikolaou@med.uni-tuebingen.de [Department of Radiology, University of Tuebingen, Hoppe-Seyler-Str. 3, 72076 Tuebingen (Germany); Reiser, Maximilian F., E-mail: Maximilian.Reiser@med.uni-muenchen.de [Institute of Clinical Radiology, Ludwig-Maximilians-University Hospital, Marchioninistrasse 15, 81377 Munich (Germany); and others

    2015-05-15

    Highlights: • Grappa-based real time cine cardiac MRI is feasible for assessment of left ventricular function. • Significant underestimation of systolic function, peak ejection and filling rates needs to be considered. • Heart rate is the only positive predictor of the deviation of obtained parameters. - Abstract: Objectives: To determine the feasibility of free-breathing, GRAPPA-based, real-time (RT) cine 3 T cardiac magnetic resonance imaging (MRI) with high acceleration factors for the assessment of left-ventricular function in a cohort of patients as compared to conventional segmented cine imaging. Materials and methods: In this prospective cohort study, subjects with various cardiac conditions underwent MRI involving two RT cine sequences (high resolution and low resolution) and standard segmented cine imaging. Standard qualitative and quantitative parameters of left-ventricular function were quantified. Results: Among 25 subjects, 24 were included in the analysis (mean age: 50.5 ± 21 years, 67% male, 25% with cardiomyopathy). RT cine derived quantitative parameters of volumes and left ventricular mass were strongly correlated with segmented cine imaging (intraclass correlation coefficient [ICC]: >0.72 for both RT cines) but correlation for peak ejection and filling rates were moderate to poor for both RT cines (ICC < 0.40). Similarly, RT cines significantly underestimated peak ejection and filling rates (>103.2 ± 178 ml/s). Among patient-related factors, heart rate was strongly predictive for deviation of measurements (p < 0.05). Conclusions: RT cine MRI at 3 T is feasible for qualitative and quantitative assessment of left ventricular function for low and high-resolution sequences but results in significant underestimation of systolic function, peak ejection and filling rates.

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

    Science.gov (United States)

    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.

  17. Sensing Cardiac Electrical Activity With a Cardiac Myocyte--Targeted Optogenetic Voltage Indicator

    NARCIS (Netherlands)

    Chang Liao, Mei-Ling; de Boer, Teun P; Mutoh, Hiroki; Raad, Nour; Richter, Claudia; Wagner, Eva; Downie, Bryan R; Unsöld, Bernhard; Arooj, Iqra; Streckfuss-Bömeke, Katrin; Döker, Stephan; Luther, Stefan; Guan, Kaomei; Wagner, Stefan; Lehnart, Stephan E; Maier, Lars S; Stühmer, Walter; Wettwer, Erich; van Veen, Toon; Morlock, Michael M; Knöpfel, Thomas; Zimmermann, Wolfram-Hubertus

    2015-01-01

    RATIONALE: Monitoring and controlling cardiac myocyte activity with optogenetic tools offer exciting possibilities for fundamental and translational cardiovascular research. Genetically encoded voltage indicators may be particularly attractive for minimal invasive and repeated assessments of cardiac

  18. Assessing continuum postulates in simulations of granular flow

    Energy Technology Data Exchange (ETDEWEB)

    Rycroft, Chris; Kamrin, Ken; Bazant, Martin

    2008-08-26

    Continuum mechanics relies on the fundamental notion of a mesoscopic volume"element" in which properties averaged over discrete particles obey deterministic relationships. Recent work on granular materials suggests a continuum law may be inapplicable, revealing inhomogeneities at the particle level, such as force chains and slow cage breaking. Here, we analyze large-scale three-dimensional Discrete-Element Method (DEM) simulations of different granular flows and show that an approximate"granular element" defined at the scale of observed dynamical correlations (roughly three to five particle diameters) has a reasonable continuum interpretation. By viewing all the simulations as an ensemble of granular elements which deform and move with the flow, we can track material evolution at a local level. Our results confirm some of the hypotheses of classical plasticity theory while contradicting others and suggest a subtle physical picture of granular failure, combining liquid-like dependence on deformation rate and solid-like dependence on strain. Our computational methods and results can be used to guide the development of more realistic continuum models, based on observed local relationships betweenaverage variables.

  19. Hazard Assessment of Debris-Flow along the Baicha River in Heshigten Banner, Inner Mongolia, China

    Science.gov (United States)

    Cao, Chen; Xu, Peihua; Chen, Jianping; Zheng, Lianjing; Niu, Cencen

    2016-01-01

    This study focused on a cloud model approach for considering debris-flow hazard assessment, in which the cloud model provided a model for transforming the qualitative and quantitative expressions. Additionally, the entropy method and analytical hierarchy process were united for calculating the parameters weights. The weighting method avoids the disadvantages inherent in using subjective or objective methods alone. Based on the cloud model and component weighting method, a model was established for the analysis of debris-flow hazard assessment. There are 29 debris-flow catchments around the pumped storage power station in the study area located near Zhirui (Inner Mongolia, China). Field survey data and 3S technologies were used for data collection. The results of the cloud model calculation process showed that of the 29 catchments, 25 had low debris-flow hazard assessment, three had moderate hazard assessment, and one had high hazard assessment. The widely used extenics method and field geological surveys were used to validate the proposed approach. This approach shows high potential as a useful tool for debris-flow hazard assessment analysis. Compared with other prediction methods, it avoids the randomness and fuzziness in uncertainty problems, and its prediction results are considered reasonable. PMID:28036079

  20. Assessing Measures of Order Flow Toxicity via Perfect Trade Classification

    DEFF Research Database (Denmark)

    Andersen, Torben G.; Bondarenko, Oleg

    . The VPIN metric involves decomposing volume into active buys and sells. We use the best-bid-offer (BBO) files from the CME Group to construct (near) perfect trade classification measures for the E-mini S&P 500 futures contract. We investigate the accuracy of the ELO Bulk Volume Classification (BVC) scheme...... and find it inferior to a standard tick rule based on individual transactions. Moreover, when VPIN is constructed from accurate classification, it behaves in a diametrically opposite way to BVC-VPIN. We also find the latter to have forecast power for short-term volatility solely because it generates...... systematic classification errors that are correlated with trading volume and return volatility. When controlling for trading intensity and volatility, the BVC-VPIN measure has no incremental predictive power for future volatility. We conclude that VPIN is not suitable for measuring order flow imbalances....

  1. Avaliação nutricional subjetiva global em pacientes cardiopatas Subjective global assessment of nutritional status in cardiac patients

    Directory of Open Access Journals (Sweden)

    Aurea Kaoru Yamauti

    2006-12-01

    capacity, and diagnosis and underwent physical examination. Then, anthropometric measurements were obtained (body weight, mid-arm circumference, triceps skinfold thickness, and arm muscle circumference. Serum albumin, total lymphocyte count and anthropometric measurements were determined for the objective assessment of patients with congestive heart failure. An ROC curve was used to analyze sensitivity, specificity and accuracy of SGA compared to the objective assessment. RESULTS: Patients' age was 57.7 ± 15.7, and the majority was male (67.9%. The ROC curve showed score 16 as SGA cut-off point with the highest sensitivity (62.2% and specificity (55.7%. The area under the curve was 0.601 (95% CI: 0.487 - 0.715. Anthropometric assessment showed malnutrition prevalence at 51.9% by SGA and 42.5% by, with accuracy of 65.3% in men and 44.1% in women. In patients with congestive heart failure, SGA assessed malnutrition prevalence was 60.4%, while objective assessment was 32.1% with accuracy of 67.6% in men and 31.3% in women. CONCLUSION: SGA detected a greater number of malnourished patients than the objective evaluation. Its performance in identifying malnutrition was better in men. It also detected cardiac patients at nutritional risk.

  2. Doppler Assessment of Uterine Blood Flow in Recurrent Pregnancy Loss

    Directory of Open Access Journals (Sweden)

    Maryam Barzin

    2011-05-01

    Full Text Available Recurrent spontaneous abortion affects 2%-5% of"ncouples. Uterine perfusion is considered as one of the"nfactors that influences the success of implantation."nDuring the normal menstrual cycle, the impedance"nto uterine artery blood flow diminishes progressively"nduring the luteal phase, reaching the lowest values"nin the period coinciding with the implantation time."nImpedance of uterine arteries is a good indicator of"nthe possibility of a subsequent pregnancy. High blood"nflow resistance is associated with a reduced conception"nrate and women with lower pulsatility index values"nhave the highest possibility of becoming pregnant. An"nimpaired uterine perfusion could play a major role in"nthe pathogenesis of recurrent spontaneous abortion. In"nthis study, we examined sixty women with recurrent"nspontaneous abortion and a control group including"nthirty normal women with at least one previous"nuncomplicated pregnancy and without history of any"nabortion. Transvaginal sonography associated with"nDoppler flow measurement was performed during"nthe midluteal phase of a cycle in all women. The"nmeasurement of the ascending branch of both right"nand left uterine arteries was taken lateral to the cervix"nat the level of the internal os. The pulsatility and"nresistance index of both uterine arteries were calculated"nand compared in both groups. In this presentation we"nreport our finding in two groups. We also explain the"nexact method of study and present some interesting"ncases

  3. DOWNFLOW code and LIDAR technology for lava flow analysis and hazard assessment at Mount Etna

    Directory of Open Access Journals (Sweden)

    Alessandro Fornaciai

    2011-12-01

    Full Text Available The use of a lava-flow simulation (DOWNFLOW probabilistic code and airborne light detection and ranging (LIDAR technology are combined to analyze the emplacement of compound lava flow fields at Mount Etna (Sicily, Italy. The goal was to assess the hazard posed by lava flows. The LIDAR-derived time series acquired during the 2006 Mount Etna eruption records the changing topography of an active lava-flow field. These short-time-interval, high-resolution topographic surveys provide a detailed quantitative picture of the topographic changes. The results highlight how the flow field evolves as a number of narrow (5-15 m wide disjointed flow units that are fed simultaneously by uneven lava pulses that advance within formed channels. These flow units have widely ranging advance velocities (3-90 m/h. Overflows, bifurcations and braiding are also clearly displayed. In such a complex scenario, the suitability of deterministic codes for lava-flow simulation can be hampered by the fundamental difficulty of measuring the flow parameters (e.g. the lava discharge rate, or the lava viscosity of a single flow unit. However, the DOWNFLOW probabilistic code approaches this point statistically and needs no direct knowledge of flow parameters. DOWNFLOW intrinsically accounts for complexities and perturbations of lava flows by randomly varying the pre-eruption topography. This DOWNFLOW code is systematically applied here over Mount Etna, to derive a lava-flow hazard map based on: (i the topography of the volcano; (ii the probability density function for vent opening; and (iii a law for the expected lava-flow length for all of the computational vents considered. Changes in the hazard due to the recent morphological evolution of Mount Etna have also been addressed.

  4. Assessment of cardiac sympathetic nerve abnormalities by {sup 123}I-MIBG (metaiodobenzylguanidine) myocardial scintigraphy in diabetic patients undergoing hemodialysis

    Energy Technology Data Exchange (ETDEWEB)

    Ohashi, Hiroshige; Oda, Hiroshi; Matsuno, Yukihiko [Prefectural Gifu Hospital (Japan)] [and others

    1995-05-01

    We compared cardiac sympathetic nerve abnormalities in patients hemodialyzed because of diabetic nephropathy (DN, n=18) and chronic glomerulonephritis (CGN, n=21). {sup 123}I-metaiodobenzylguanidine (MIBG) myocardial scintigraphy was performed in this study. SPECT and anterior planar myocardial images were obtained 15 minutes after (initial images) and 4 hours after (delayed images) an injection of MIBG. The following results were obtained: (1) SPECT showed more defects in DN than in CGN. (2) The heart to superior mediastinum uptake ratio (H/M) was lower in DN than in CGN. These findings suggest that myocardial uptake of MIBG in DN is significantly impaired because of cardiac sympathetic nerve abnormalities. These abnormalities may affect the prognosis in DN. (author).

  5. Diagnostic performance of cardiac imaging methods to diagnose ischaemia-causing coronary artery disease when directly compared with fractional flow reserve as a reference standard: a meta-analysis

    Science.gov (United States)

    Danad, Ibrahim; Szymonifka, Jackie; Twisk, Jos W.R.; Norgaard, Bjarne L.; Zarins, Christopher K.; Knaapen, Paul

    2017-01-01

    Aims The aim of this study was to determine the diagnostic performance of single-photon emission computed tomography (SPECT), stress echocardiography (SE), invasive coronary angiography (ICA), coronary computed tomography angiography (CCTA), fractional flow reserve (FFR) derived from CCTA (FFRCT), and cardiac magnetic resonance (MRI) imaging when directly compared with an FFR reference standard. Method and results PubMed and Web of Knowledge were searched for investigations published between 1 January 2002 and 28 February 2015. Studies performing FFR in at least 75% of coronary vessels for the diagnosis of ischaemic coronary artery disease (CAD) were included. Twenty-three articles reporting on 3788 patients and 5323 vessels were identified. Meta-analysis was performed for pooled sensitivity, specificity, likelihood ratios (LR), diagnostic odds ratio, and summary receiver operating characteristic curves. In contrast to ICA, CCTA, and FFRCT reports, studies evaluating SPECT, SE, and MRI were largely retrospective, single-centre and with generally smaller study samples. On a per-patient basis, the sensitivity of CCTA (90%, 95% CI: 86–93), FFRCT (90%, 95% CI: 85–93), and MRI (90%, 95% CI: 75–97) were higher than for SPECT (70%, 95% CI: 59–80), SE (77%, 95% CI: 61–88), and ICA (69%, 95% CI: 65–75). The highest and lowest per-patient specificity was observed for MRI (94%, 95% CI: 79–99) and for CCTA (39%, 95% CI: 34–44), respectively. Similar specificities were noted for SPECT (78%, 95% CI: 68–87), SE (75%, 95% CI: 63–85), FFRCT (71%, 95% CI: 65–75%), and ICA (67%, 95% CI: 63–71). On a per-vessel basis, the highest sensitivity was for CCTA (pooled sensitivity, 91%: 88–93), MRI (91%: 84–95), and FFRCT (83%, 78–87), with lower sensitivities for ICA (71%, 69–74), and SPECT (57%: 49–64). Per-vessel specificity was highest for MRI (85%, 79–89), FFRCT (78%: 78–81), and SPECT (75%: 69–80), whereas ICA (66%: 64–68) and CCTA (58%: 55

  6. Preserved metabolic coupling and cerebrovascular reactivity during mild hypothermia after cardiac arrest.

    NARCIS (Netherlands)

    Bisschops, L.L.A.; Hoedemaekers, C.W.E.; Simons, K.S.; Hoeven, J.G. van der

    2010-01-01

    OBJECTIVE: Although mild hypothermia improves outcome in patients after out-of-hospital cardiac arrest, the cardiodepressive effects of hypothermia may lead to secondary brain damage. This study was performed to assess the cerebral blood flow, cerebral oxygen extraction, and cerebrovascular reactivi

  7. Prehospital randomised assessment of a mechanical compression device in cardiac arrest (PaRAMeDIC) trial protocol

    OpenAIRE

    McCabe Chris; Lamb Sarah E; Lall Ranjit; Horton Jessica; Deakin Charles; Cooke Matthew W; Woollard Malcolm; Perkins Gavin D; Quinn Tom; Slowther Anne; Gates Simon

    2010-01-01

    Abstract Background Survival after out-of-hospital cardiac arrest is closely linked to the quality of CPR, but in real life, resuscitation during prehospital care and ambulance transport is often suboptimal. Mechanical chest compression devices deliver consistent chest compressions, are not prone to fatigue and could potentially overcome some of the limitations of manual chest compression. However, there is no high-quality evidence that they improve clinical outcomes, or that they are cost ef...

  8. The assessment of cardiac functions by tissue Doppler-derived myocardial performance index in patients with Behcet's disease.

    Science.gov (United States)

    Tavil, Yusuf; Ozturk, Mehmet Akif; Sen, Nihat; Kaya, Mehmet Gungor; Hizal, Fatma; Poyraz, Fatih; Turfan, Murat; Onder, Meltem; Gurer, Mehmet Ali; Cengel, Atiye

    2008-03-01

    Vascular involvement is one of the major characteristics of Behcet's disease (BD). However, there are controversial findings regarding cardiac involvement in BD. Although early reports demonstrated that there is diastolic dysfunction in BD, conflicting results were found in the following trials. Hence, a new method for more objectively estimating the cardiac functions is needed. For this aim, we used high-usefulness tissue Doppler echocardiography for detailed analysis of cardiac changes in BD patients because this method was superior to other conventional echocardiographic techniques. The study population included 42 patients with BD (19 men, 23 women; mean age, 35 +/- 10 years, mean disease duration, 2.7 +/- 1.6 years) and 30 healthy subjects (14 men, 16 women; mean age, 38 +/- 7 years). Cardiac functions were determined using echocardiography, comprising standard two-dimensional and conventional Doppler and tissue Doppler imaging (TDI). Peak systolic myocardial velocity at mitral annulus, early diastolic mitral annular velocity (Em), late diastolic mitral annular velocity (Am), Em/Am, and myocardial performance index (MPI) were calculated by TDI. The conventional echocardiographic parameters and tissue Doppler measurements were similar between the groups. Tissue Doppler derived mitral relaxation time was longer (75 +/- 13 vs 63 +/- 16 msn, p = 0.021) in patients with BD. There was statistically significant difference between the two groups regarding left ventricular MPI (0.458 +/- 0.072 vs 0.416 +/- 0.068%, p = 0.016), which were calculated from tissue Doppler systolic time intervals. There was also significant correlation between the disease duration and MPI (r = 0.38, p = 0.017). We have demonstrated that tissue Doppler-derived myocardial left ventricular relaxation time and MPI were impaired in BD patients, although systolic and diastolic function parameters were comparable in the patients and controls.

  9. Cardiac cameras.

    Science.gov (United States)

    Travin, Mark I

    2011-05-01

    Cardiac imaging with radiotracers plays an important role in patient evaluation, and the development of suitable imaging instruments has been crucial. While initially performed with the rectilinear scanner that slowly transmitted, in a row-by-row fashion, cardiac count distributions onto various printing media, the Anger scintillation camera allowed electronic determination of tracer energies and of the distribution of radioactive counts in 2D space. Increased sophistication of cardiac cameras and development of powerful computers to analyze, display, and quantify data has been essential to making radionuclide cardiac imaging a key component of the cardiac work-up. Newer processing algorithms and solid state cameras, fundamentally different from the Anger camera, show promise to provide higher counting efficiency and resolution, leading to better image quality, more patient comfort and potentially lower radiation exposure. While the focus has been on myocardial perfusion imaging with single-photon emission computed tomography, increased use of positron emission tomography is broadening the field to include molecular imaging of the myocardium and of the coronary vasculature. Further advances may require integrating cardiac nuclear cameras with other imaging devices, ie, hybrid imaging cameras. The goal is to image the heart and its physiological processes as accurately as possible, to prevent and cure disease processes.

  10. Linking rainfall-induced landslides with debris flows runout patterns towards catchment scale hazard assessment

    Science.gov (United States)

    Fan, Linfeng; Lehmann, Peter; McArdell, Brian; Or, Dani

    2017-03-01

    Debris flows and landslides induced by heavy rainfall represent an ubiquitous and destructive natural hazard in steep mountainous regions. For debris flows initiated by shallow landslides, the prediction of the resulting pathways and associated hazard is often hindered by uncertainty in determining initiation locations, volumes and mechanical state of the mobilized debris (and by model parameterization). We propose a framework for linking a simplified physically-based debris flow runout model with a novel Landslide Hydro-mechanical Triggering (LHT) model to obtain a coupled landslide-debris flow susceptibility and hazard assessment. We first compared the simplified debris flow model of Perla (1980) with a state-of-the art continuum-based model (RAMMS) and with an empirical model of Rickenmann (1999) at the catchment scale. The results indicate that predicted runout distances by the Perla model are in reasonable agreement with inventory measurements and with the other models. Predictions of localized shallow landslides by LHT model provides information on water content of released mass. To incorporate effects of water content and flow viscosity as provided by LHT on debris flow runout, we adapted the Perla model. The proposed integral link between landslide triggering susceptibility quantified by LHT and subsequent debris flow runout hazard calculation using the adapted Perla model provides a spatially and temporally resolved framework for real-time hazard assessment at the catchment scale or along critical infrastructure (roads, railroad lines).

  11. Trends in Flow-based Biosensing Systems for Pesticide Assessment

    Directory of Open Access Journals (Sweden)

    Jean-Louis Marty

    2006-10-01

    Full Text Available This review gives a survey on the state of the art of pesticide detection usingflow-based biosensing systems for sample screening. Although immunosensor systems havebeen proposed as powerful pesticide monitoring tools, this review is mainly focused onenzyme-based biosensors, as they are the most commonly employed when using a flowsystem. Among the different detection methods able to be integrated into flow-injectionanalysis (FIA systems, the electrochemical ones will be treated in more detail, due to theirhigh sensitivity, simple sample pretreatment, easy operational procedures and real-timedetection. During the last decade, new trends have been emerging in order to increase theenzyme stability, the sensitivity and selectivity of the measurements, and to lower thedetection limits. These approaches are based on (i the design of novel matrices for enzymeimmobilisation, (ii new manifold configurations of the FIA system, sometimes includingminiaturisation or lab-on-chip protocols thanks to micromachining technology, (iii the useof cholinesterase enzymes either from various commercial sources or genetically modifiedwith the aim of being more sensitive, (iv the incorporation of other highly specificenzymes, such as organophosphate hydrolase (OPH or parathion hydrolase (PH and (v thecombination of different electrochemical methods of detection. This article discusses thesenovel strategies and their advantages and limitations.

  12. Reevaluating multicolor flow cytometry to assess microbial viability.

    Science.gov (United States)

    Buysschaert, Benjamin; Byloos, Bo; Leys, Natalie; Van Houdt, Rob; Boon, Nico

    2016-11-01

    Flow cytometry is a rapid and quantitative method to determine bacterial viability. Although different stains can be used to establish viability, staining protocols are inconsistent and lack a general optimization approach. Very few "true" multicolor protocols, where dyes are combined in one sample, have been developed for microbiological applications. In this mini-review, the discrepancy between protocols for cell-permeant nucleic acid and functional stains are discussed as well as their use as viability dyes. Furthermore, optimization of staining protocols for a specific setup are described. Original data using the red-excitable SYTO dyes SYTO 59 to 64 and SYTO 17, combined with functional stains, for double and triple staining applications is also included. As each dye and dye combination behaves differently within a certain combination of medium matrix, microorganism, and instrument, protocols need to be tuned to obtain reproducible results. Therefore, single, double, and triple stains are reviewed, including the different parameters that influence staining such as stain kinetics, optimal stain concentration, and the effect of the chelator EDTA as membrane permeabilizer. In the last section, we highlight the need to investigate the stability of multicolor assays to ensure correct results as multiwell autoloaders are now commonly used.

  13. Qualitative Assessment of Flow and Transport Mechanisms in Bioremediation Processes

    Science.gov (United States)

    Terry, N.; Hou, Z.

    2008-12-01

    Recent studies suggest that time-lapse crosshole geophysical methods may be effective in monitoring subsurface hydrological and biochemical mechanisms. These methods have potential to provide a minimally invasive, cost-effective, high resolution, field relevant means to gain information previously limited to wellbore data. Our study area is located at a DOE Hanford site, an area heavily polluted with toxic chromate. Time- lapse crosshole seismic and radar data sets have been collected in order to monitor spatio-temporal responses to these processes. Before using these data for parameter estimation and monitoring hydrobiogeochemical processes, we need to 1) identify the critical parameters involved in these processes; 2) determine the sensitivity of seismic/radar responses to these parameters; and 3) choose the most appropriate forward modeling approach for forward and inverse modeling. In this study, we treat critical parameters (e.g., hydraulic conductivity, flow rate, and the dispersion coefficients) as random variables, which can be described by their probabilistic density distributions. Then we adopt stochastic sampling method within the Minimum relative entropy (MRE) framework to generate many realistic models based on the welllog data. From here, the geophysical (crosshole seismic and radar) responses are computed using different forward models to study the sensitivity of the responses to those aforementioned parameters, and the performances of the different forward modeling approaches are compared. Finally, geophysical data are used for hydrobiogeochemical parameter estimation through Bayesian inverse modeling. Our study provides guidance on favorable situations in which borehole geophysical data can be effectively used for monitoring subsurface hydrobiogeochemical processes.

  14. Assessing the performance of ultrafast vector flow imaging in the neonatal heart via multiphysics modeling and in-vitro experiments.

    Science.gov (United States)

    Van Cauwenberge, Joris; Lovstakken, Lasse; Fadnes, Solveig; Rodriguez-Molares, Alfonso; Vierendeels, Jan; Segers, Patrick; Swillens, Abigail

    2016-08-01

    Ultrafast vector flow imaging would benefit newborn patients with congenital heart disorders, but still requires thorough validation before translation to clinical practice. This study investigates 2D speckle tracking of intraventricular blood flow in neonates when transmitting diverging waves at ultrafast frame rate. Computational and in-vitro studies enabled us to quantify the performance and identify artefacts related to the flow and the imaging sequence. First, synthetic ultrasound images of a neonate's left ventricular flow pattern were obtained with the ultrasound simulator Field II by propagating point scatterers according to 3D intraventricular flow fields obtained with computational fluid dynamics (CFD). Non-compounded diverging waves (opening angle of 60°) were transmitted at a pulse repetition frequency of 9 kHz. Speckle tracking of the B-mode data provided 2D flow estimates at 180 Hz, which were compared to the CFD flow field. We demonstrated that the diastolic inflow jet showed a strong bias in the lateral velocity estimates at the edges of the jet, as confirmed by additional in-vitro tests on a jet flow phantom. Further, speckle tracking performance was highly dependent on the cardiac phase with low flows (flow gradients and out-of-plane flow as deteriorating factors. Despite the observed artefacts, a good overall performance of 2D speckle tracking was obtained with a median magnitude underestimation and angular deviation of respectively 28% and 13.5° during systole, and 16% and 10.5° during diastole.

  15. Assessing the Performance of Ultrafast Vector Flow Imaging in the Neonatal Heart via Multiphysics Modeling and In Vitro Experiments.

    Science.gov (United States)

    Van Cauwenberge, Joris; Lovstakken, Lasse; Fadnes, Solveig; Rodriguez-Morales, Alfonso; Vierendeels, Jan; Segers, Patrick; Swillens, Abigail

    2016-11-01

    Ultrafast vector flow imaging would benefit newborn patients with congenital heart disorders, but still requires thorough validation before translation to clinical practice. This paper investigates 2-D speckle tracking (ST) of intraventricular blood flow in neonates when transmitting diverging waves at ultrafast frame rate. Computational and in vitro studies enabled us to quantify the performance and identify artifacts related to the flow and the imaging sequence. First, synthetic ultrasound images of a neonate's left ventricular flow pattern were obtained with the ultrasound simulator Field II by propagating point scatterers according to 3-D intraventricular flow fields obtained with computational fluid dynamics (CFD). Noncompounded diverging waves (opening angle of 60°) were transmitted at a pulse repetition frequency of 9 kHz. ST of the B-mode data provided 2-D flow estimates at 180 Hz, which were compared with the CFD flow field. We demonstrated that the diastolic inflow jet showed a strong bias in the lateral velocity estimates at the edges of the jet, as confirmed by additional in vitro tests on a jet flow phantom. Furthermore, ST performance was highly dependent on the cardiac phase with low flows (flow gradients, and out-of-plane flow as deteriorating factors. Despite the observed artifacts, a good overall performance of 2-D ST was obtained with a median magnitude underestimation and angular deviation of, respectively, 28% and 13.5° during systole and 16% and 10.5° during diastole.

  16. Multi-slice spiral computed tomography assessment of cardiac diverticula%多层螺旋CT对心脏憩室的诊断价值

    Institute of Scientific and Technical Information of China (English)

    周碧; 赵静; 朱洪章; 杨有优

    2015-01-01

    目的:探讨多层螺旋CT(MSCT)在心脏憩室诊断中的临床价值。方法回顾性分析11例心脏憩室患者的临床及MSCT资料,行多种后处理技术分析心脏憩室形态表现及其他并发异常。结果11例患者心脏憩室均为单发,分别位于左心室(4例)、右心房(3例)、左心房(2例)、右心室(2例)。10例憩室呈囊袋状,1例憩室呈不规则管状,以窄颈与心腔相通,最大径2.5~8.8 cm。本组3例纤维型心室憩室壁薄、伴钙化,2例肌肉型心室憩室壁较厚。3例右心房憩室合并房间隔缺损,1例左心室憩室合并复杂心内外畸形。结论 MSCT能清楚显示心脏憩室位置、形态及大小,可为心室憩室类型判断提供依据,并能提示合并的心内外异常,是较为理想的心脏憩室非侵入性检查手段。%Objective To assess the value of multi-slice spiral computed tomography (MSCT) in the diagnosis of cardiac diverticula. Methods Cardiac MSCT of 11 patients with surgically or pathologically confirmed cardiac diverticula were retrospectively analyzed. Results The cardiac diverticula were isolated and located in the left ventricle (4), right atrium (3), left atrium (2) and right ventricle(2). The diverticula were protruding sac-like(10) or irregular tube-like(1) in shape with longitudinal diameters of 2.5-8.8 cm and were connected to the cardiac cavity by a narrow neck. The diverticular walls were unevenly thin and calcified in 3 fibrous ventricular diverticula and thick in 2 muscular diverticula..Three right atrial diverticula were associated with atrial septal defect and 1 left ventricular diverticulum was accompanied with complex malformations. Conclusion MSCT can clearly depict the location, morphology, size and type of cardiac diverticula and the associated cardiac malformation.

  17. Avaliação da doença vascular do enxerto no transplante cardíaco: experiência de um centro brasileiro Assessment of cardiac allograft vasculopathy in cardiac transplantation: experience of a Brazilian center

    Directory of Open Access Journals (Sweden)

    Elide Sbardellotto Mariano da Costa

    2012-10-01

    allograft vasculopathy (CAV, important causes of mortality after transplantation. OBJECTIVE: To assess the relationship between intravascular ultrasound (IVUS results and endomyocardial biopsy (BX reports in the follow-up of patients undergoing cardiac transplantation in a Brazilian reference service. METHODS: A retrospective epidemiological observational study was carried out with patients undergoing orthotopic cardiac transplantation from 2000 to 2009. The study assessed the medical records of those patients and the results of the IVUS and BX routinely performed in the clinical post-transplant follow-up, as well as the therapy used. RESULTS: Of the 77 patients assessed, 63.63% were males, their ages ranging from 22 to 69 years. Regarding the IVUS results, 33.96% of the patients were classified as Stanford class I, and 32.08%, as Stanford class IV. Of the 143 BX reports, 51.08% were 1R, and 0.69%, 3R. The Quilty effect was described in 14.48% of the BX reports. All patients used antiproliferative agents, 80.51% used calcineurin inhibitors, and 19.48% used proliferation signal inhibitors. CONCLUSION: The assessment of cardiac transplant patients by use of IVUS provides detailed information for the early and sensitive diagnosis of CAV, which is complemented by histological data derived from BX, establishing a possible causal relationship between CAV and humoral rejection episodes.

  18. Simulation and Assessment of Whole Life-Cycle Carbon Emission Flows from Different Residential Structures

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    Rikun Wen

    2016-08-01

    Full Text Available To explore the differences in carbon emissions over the whole life-cycle of different building structures, the published calculated carbon emissions from residential buildings in China and abroad were normalized. Embodied carbon emission flows, operations stage carbon emission flows, demolition and reclamation stage carbon emission flows and total life-cycle carbon emission flows from concrete, steel, and wood structures were obtained. This study is based on the theory of the social cost of carbon, with an adequately demonstrated social cost of carbon and social discount rate. Taking into consideration both static and dynamic situations and using a social discount rate of 3.5%, the total life-cycle carbon emission flows, absolute carbon emission and building carbon costs were calculated and assessed. The results indicated that concrete structures had the highest embodied carbon emission flows and negative carbon emission flows in the waste and reclamation stage. Wood structures that started the life-cycle with stored carbon had the lowest carbon emission flows in the operations stage and relatively high negative carbon emission flows in the reclamation stage. Wood structures present the smallest carbon footprints for residential buildings.

  19. Assessment of the kinetic-frictional model for dense granular flow

    Institute of Scientific and Technical Information of China (English)

    Boon Ho Ng; Yulong Ding; Mojtaba Ghadiri

    2008-01-01

    This paper aims to quantitatively assess the application of kinetic-frictional model to simulate the motion of dry granular materials in dense condition, in particular, the annular shearing in Couette configuration. The weight of frictional stress was varied to study the contribution of the frictional stress in dense granular flows. The results show that the pure kinetic-theory-based computational fluid dynamics (CFD) model (without frictional stress) over-predicts the dominant solids motion of dense granular flow while adding frictional stress [Schaeffer, D. G. (1987). Instability in the evolution equations describing incompressible granular flow. Journal of Differential Equations, 66(1), 19-50] with the solids pressure of [Lun, C. KTK., Savage, S. B., Jeffrey, D. J., & Chepurniy, N. (1984). Kinetic theories for granular flow: Inelastic particles in Couette flow and slightly inelastic particles in a general flow field. Journal of Fluid Mechanics, 140, 223-256] in the CFD model improves the simulation to better conform available experimental results. The results also suggest that frictional stress transmission plays an important role in dense granular flow and should not be neglected in granular flow simulations. Compatible simulation results to the experimental data are seen by increasing the weight of frictional stress to a factor of 1.25-1.5. These improved simulation results suggest the current constitutive relations (kinetic-frictional model) need to be improved in order to better reflect the real dense granular flow.

  20. Cardiac Electrophysiology: Normal and Ischemic Ionic Currents and the ECG

    Science.gov (United States)

    Klabunde, Richard E.

    2017-01-01

    Basic cardiac electrophysiology is foundational to understanding normal cardiac function in terms of rate and rhythm and initiation of cardiac muscle contraction. The primary clinical tool for assessing cardiac electrical events is the electrocardiogram (ECG), which provides global and regional information on rate, rhythm, and electrical…

  1. In vivo functional imaging of blood flow and wall strain rate in outflow tract of embryonic chick heart using ultrafast spectral domain optical coherence tomography

    Science.gov (United States)

    Li, Peng; Yin, Xin; Shi, Liang; Rugonyi, Sandra; Wang, Ruikang K.

    2012-09-01

    During cardiac development, the cardiac wall and flowing blood are two important cardiac tissues that constantly interact with each other. This dynamic interaction defines appropriate biomechanical environment to which the embryonic heart is exposed. Quantitative assessment of the dynamic parameters of wall tissues and blood flow is required to further our understanding of cardiac development. We report the use of an ultrafast 1310-nm dual-camera spectral domain optical coherence tomography (SDOCT) system to characterize/image, in parallel, the dynamic radial strain rate of the myocardial wall and the Doppler velocity of the underlying flowing blood within an in vivo beating chick embryo. The OCT system operates at 184-kHz line scan rate, providing the flexibility of imaging the fast blood flow and the slow tissue deformation within one scan. The ability to simultaneously characterize tissue motion and blood flow provides a useful approach to better understand cardiac dynamics during early developmental stages.

  2. Noninvasive monitoring of cardiac function in a chronic ischemic heart failure model in the rat: Assessment with tissue Doppler and non-Doppler 2D strain echocardiography

    Directory of Open Access Journals (Sweden)

    Baumann Gert

    2011-05-01

    Full Text Available Abstract Objectives Feasibility of noninvasive monitoring of cardiac function after surgically induced ischemic cardiomyopathy with tissue Doppler and non-Doppler 2D strain echocardiography in rats. Background The optimal method for quantitative assessment of global and regional ventricular function in rats with chronic heart failure for research purposes remains unclear. Methods 20 rats underwent suture ligation of the left anterior descending coronary artery via a left thoracotomy to induce ischemic cardiomyopathy. Echocardiographic examination with estimation of left ventricular wall thickness, diameters, fractional shortening, ejection fraction, wall velocities as well as radial strain were performed before and 4 weeks after surgery. Results Mean LVEF decreased from 70 ± 6% to 40 ± 8% (p Conclusion It is feasible to assess dimensions, global function, and regional contractility with echocardiography in rats suffering from chronic heart failure after myocardial infarction. Particularly regional function can be exactly evaluated if tissue Doppler and 2D strain is used.

  3. Site-specific Vulnerability Assessment for Debris Flows: Two Case Studies

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Here the vulnerability is defined as the potential total maximum losses due to a debris flow damaging event for a specific debris flow fan. The vulnerability is classified into property vulnerability and population vulnerability. Assessment indexes include the assets of buildings, traffic facilities, lifeline works, personal properties, and land resources for property vulnerability; age, education, and wealth of the inhabitants, natural population growth rate, and population density for population vulnerability. The vulnerability is expressed as the sum of the transformed values of the losses of property and population. Two study cases with post-fact damages by historic debris flow events in Sichuan of SW China are presented.

  4. Assessment of the debris-flow susceptibility in tropical mountains using clast distribution patterns

    Science.gov (United States)

    de Carvalho Faria Lima Lopes, Laís; de Almeida Prado Bacellar, Luís; Amorim Castro, Paulo de Tarso

    2016-12-01

    Channel morphometric parameters and clast distribution patterns in selected basins of the Ferriferous Quadrangle tropical mountains, Brazil, were analyzed in order to assess susceptibility to debris flows. Median bed surface clast size (D50) in the main stream channel of these basins shows a coarsening downstream trend with drainage areas of up to 6 km2, which is attributed to debris flow dominated-channels by some authors. The composition and roundness of the bed load, clast sand, and the presence of allochthonous large boulders throughout the channels also suggest the occurrence of past debris flow in the region. Luminescence Optically Stimulated (LOE) dating points out that debris flow could have occurred as a consequence of climate changes in the Late Pleistocene and Holocene and it can now be triggered by deforestation or extreme rainfall events. There has not been any record of past debris flow in the study area, or in other mountainous regions of Brazil where debris flows have recently occurred. Thus, the adopted approach can be useful to assess debris flow susceptibility in this and other similar areas.

  5. A biological tool to assess flow connectivity in reference temporary streams from the Mediterranean Basin

    Energy Technology Data Exchange (ETDEWEB)

    Cid, N., E-mail: ncid@ub.edu [Grup de Recerca “Freshwater Ecology and Management (FEM)”, Departament d' Ecologia, Universitat de Barcelona, Catalonia (Spain); Verkaik, I. [Grup de Recerca “Freshwater Ecology and Management (FEM)”, Departament d' Ecologia, Universitat de Barcelona, Catalonia (Spain); García-Roger, E.M. [Grup de Recerca “Freshwater Ecology and Management (FEM)”, Departament d' Ecologia, Universitat de Barcelona, Catalonia (Spain); Institut Cavanilles de Biodiversitat i Biologia Evolutiva, Universitat de València (Spain); Rieradevall, M.; Bonada, N. [Grup de Recerca “Freshwater Ecology and Management (FEM)”, Departament d' Ecologia, Universitat de Barcelona, Catalonia (Spain); Sánchez-Montoya, M.M. [Department of Ecology and Hydrology, Regional Campus of International Excellence “Campus Mare Nostrum”—University of Murcia (Spain); Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB), Berlin (Germany); Gómez, R.; Suárez, M.L.; Vidal-Abarca, M.R. [Department of Ecology and Hydrology, Regional Campus of International Excellence “Campus Mare Nostrum”—University of Murcia (Spain); Demartini, D.; Buffagni, A.; Erba, S. [Instituto di Ricerca Sulle Acque (CNR-IRSA) (Italy); Karaouzas, I.; Skoulikidis, N. [Hellenic Center for Marine Research (HCMR) (Greece); Prat, N. [Grup de Recerca “Freshwater Ecology and Management (FEM)”, Departament d' Ecologia, Universitat de Barcelona, Catalonia (Spain)

    2016-01-01

    Many streams in the Mediterranean Basin have temporary flow regimes. While timing for seasonal drought is predictable, they undergo strong inter-annual variability in flow intensity. This high hydrological variability and associated ecological responses challenge the ecological status assessment of temporary streams, particularly when setting reference conditions. This study examined the effects of flow connectivity in aquatic macroinvertebrates from seven reference temporary streams across the Mediterranean Basin where hydrological variability and flow conditions are well studied. We tested for the effect of flow cessation on two streamflow indices and on community composition, and, by performing random forest and classification tree analyses we identified important biological predictors for classifying the aquatic state either as flowing or disconnected pools. Flow cessation was critical for one of the streamflow indices studied and for community composition. Macroinvertebrate families found to be important for classifying the aquatic state were Hydrophilidae, Simuliidae, Hydropsychidae, Planorbiidae, Heptageniidae and Gerridae. For biological traits, trait categories associated to feeding habits, food, locomotion and substrate relation were the most important and provided more accurate predictions compared to taxonomy. A combination of selected metrics and associated thresholds based on the most important biological predictors (i.e. Bio-AS Tool) were proposed in order to assess the aquatic state in reference temporary streams, especially in the absence of hydrological data. Although further development is needed, the tool can be of particular interest for monitoring, restoration, and conservation purposes, representing an important step towards an adequate management of temporary rivers not only in the Mediterranean Basin but also in other regions vulnerable to the effects of climate change. - Highlights: • The effect of flow connectivity on macroinvertebrate

  6. Assessment of the dose distribution inside a cardiac cath lab using TLD measurements and Monte Carlo simulations

    Science.gov (United States)

    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

  7. Prognostic factors for mortality among patients above the 6th decade undergoing non-cardiac surgery: cares - clinical assessment and research in elderly surgical patients

    Directory of Open Access Journals (Sweden)

    Adriana Nunes Machado

    2008-01-01

    Full Text Available PURPOSE: To ascertain perioperative morbimortality and identify prognostic factors for mortality among patients >55 years who undergo non-cardiac surgery. METHODS: A retrospective cohort of 403 patients relating to perioperative morbidity-mortality. Data were collected from a standardized protocol on gender, age, comorbidities, medications used, smoking, alcohol abuse, chronic use of benzodiazepine, nutritional status, presence of anemia, activities of daily living, American Society of Anesthesiology classification, Detsky's modified cardiac risk index - American College of Physicians, renal function evaluation, pulmonary risk according to the Torrington scale, risk of thromboembolic events, presence of malignant disease and complementary examinations. RESULTS: The mean age of the subjects was 70.8 ± 8.1 years. The "very old" (>80 years represented 14%. The mortality rate was 8.2%, and the complication rate was 15.8%. Multiple logistic regression showed that a history of coronary heart disease (OR: 3.75; p=0.02 and/or valvular heart disease (OR: 31.79; p=0.006 were predictors of mortality. The American Society of Anesthesiology classification was shown to be the best scale to mark risk (OR: 3.01; p=0.016. Nutritional status was a protective factor, in which serum albumin increases of 1 mg/dl decreased risk by 63%. DISCUSSION: The results indicate that serum albumin, coronary heart disease, valvular heart disease and the American Society of Anesthesiology classification could be prognostic predictors for aged patients in a perioperative setting. In this sample, provided that pulmonary, cardiac and thromboembolic risks were properly controlled, they did not constitute risk factors for mortality. Furthermore, continuous effort to learn more about the preoperative assessment of elderly patients could yield intervention possibilities and minimize morbimortality.

  8. Anti-addiction drug ibogaine inhibits voltage-gated ionic currents: a study to assess the drug's cardiac ion channel profile.

    Science.gov (United States)

    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.

  9. Fractional flow reserve and resting indices for coronary physiologic assessment: Practical guide, tips, and tricks.

    Science.gov (United States)

    Picard, Fabien; Pighi, Michele; Ly, Hung Q

    2017-02-04

    Physiologic assessment using fractional flow reserve (FFR) to guide percutaneous coronary interventions (PCI) has been demonstrated to improve clinical outcomes, compared to angiography-guided PCI. Recently, resting indices such as resting Pd/Pa, "instantaneous wave-free ratio", and contrast medium induced FFR have been evaluated for the assessment of the functional consequences of coronary lesions. Herein, we review and discuss the use of FFR and other indices for the functional assessment of coronary lesions. This review will cover theoretical aspects, as well as practical points and common pitfalls related to coronary physiological assessment. © 2017 Wiley Periodicals, Inc.

  10. Cardiac echinococcosis

    Directory of Open Access Journals (Sweden)

    Ivanović-Krstić Branislava A.

    2002-01-01

    Full Text Available Cardiac hydatid disease is rare. We report on an uncommon hydatid cyst localized in the right ventricular wall, right atrial wall tricuspid valve left atrium and pericard. A 33-year-old woman was treated for cough, fever and chest pain. Cardiac echocardiograpic examination revealed a round tumor (5.8 x 4 cm in the right ventricular free wall and two smaller cysts behind that tumor. There were cysts in right atrial wall and tricuspidal valve as well. Serologic tests for hydatidosis were positive. Computed tomography finding was consistent with diagnosis of hydatid cyst in lungs and right hylar part. Surgical treatment was rejected due to great risk of cardiac perforation. Medical treatment with albendazole was unsuccessful and the patient died due to systemic hydatid involvement of the lungs, liver and central nervous system.

  11. Current Roles and Future Applications of Cardiac CT: Risk Stratification of Coronary Artery Disease

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Yeonyee Elizabeth [Department of Cardiology, Cardiovascular Center, Seoul National University Bundang Hospital, Seongnam 463-707 (Korea, Republic of); Lim, Tae-Hwan [Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 138-736 (Korea, Republic of)

    2014-07-01

    Cardiac computed tomography (CT) has emerged as a noninvasive modality for the assessment of coronary artery disease (CAD), and has been rapidly integrated into clinical cares. CT has changed the traditional risk stratification based on clinical risk to image-based identification of patient risk. Cardiac CT, including coronary artery calcium score and coronary CT angiography, can provide prognostic information and is expected to improve risk stratification of CAD. Currently used conventional cardiac CT, provides accurate anatomic information but not functional significance of CAD, and it may not be sufficient to guide treatments such as revascularization. Recently, myocardial CT perfusion imaging, intracoronary luminal attenuation gradient, and CT-derived computed fractional flow reserve were developed to combine anatomical and functional data. Although at present, the diagnostic and prognostic value of these novel technologies needs to be evaluated further, it is expected that all-in-one cardiac CT can guide treatment and improve patient outcomes in the near future.

  12. Clinical impact of left ventricular eccentricity index using cardiac MRI in assessment of right ventricular hemodynamics and myocardial fibrosis in congenital heart disease

    Energy Technology Data Exchange (ETDEWEB)

    Yamasaki, Yuzo; Kamitani, Takeshi; Yamanouchi, Torahiko; Honda, Hiroshi [Kyushu University, Departments of Clinical Radiology, Graduate School of Medical Sciences, Fukuoka (Japan); Nagao, Michinobu; Kawanami, Satoshi [Kyushu University, Molecular Imaging and Diagnosis, Graduate School of Medical Sciences, Fukuoka (Japan); Yamamura, Kenichiro [Kyushu University, Pediatrics, Graduate School of Medical Sciences, Fukuoka (Japan); Sakamoto, Ichiro [Kyushu University, Cardiovascular Medicine, Graduate School of Medical Sciences, Fukuoka (Japan); Yabuuchi, Hidetake [Kyushu University, Health SciencesGraduate School of Medical Sciences, Fukuoka (Japan)

    2016-10-15

    To investigate the utility of eccentricity index (EI) using cardiac cine MRI for the assessment of right ventricular (RV) hemodynamics in congenital heart disease (CHD). Fifty-five patients with CHD (32 women; mean age, 40.7 ± 20.9 years) underwent both cardiac MRI and right heart catheterization. EI was defined as the ratio of the distance between the anterior-posterior wall and the septal-lateral wall measured in the short-axis of mid-ventricular cine MRI. Correlations between EIs and RV hemodynamic parameters were analyzed. EIs were compared between patients with and without late gadolinium enhancement (LGE). A strong correlation between mean pulmonary artery pressure (PAP) and systolic EI (r = 0.81, p < 0.0001) and a moderate negative correlation between diastolic EI and RV ejection fraction (EF) (r = -0.62, p < 0.0001) were observed. Receiver operating characteristic analysis revealed optimal EI thresholds for detecting patients with mean PAP ≥40 mmHg with C-statistics of 0.90 and patients with RVEF <40 % with C-statistics of 0.78. Systolic EIs were significantly greater for patients with LGE (1.45 ± 0.05) than for those without LGE (1.15 ± 0.07; p < 0.001). EI offers a simple, comprehensive index that can predict pulmonary hypertension and RV dysfunction in CHD. (orig.)

  13. Aortic stiffness is associated with cardiac function and cerebral small vessel disease in patients with type 1 diabetes mellitus: assessment by magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Elderen, Saskia G.C. van; Brandts, A.; Westenberg, J.J.M.; Grond, J. van der; Buchem, M.A. van; Kroft, L.J.M.; Roos, A. de [Leiden University Medical Center, Department of Radiology, Leiden (Netherlands); Tamsma, J.T.; Romijn, J.A.; Smit, J.W.A. [Leiden University Medical Center, Department of Endocrinology, Leiden (Netherlands)

    2010-05-15

    To evaluate, with the use of magnetic resonance imaging (MRI), whether aortic pulse wave velocity (PWV) is associated with cardiac left ventricular (LV) function and mass as well as with cerebral small vessel disease in patients with type 1 diabetes mellitus (DM). We included 86 consecutive type 1 DM patients (49 male, mean age 46.9 {+-} 11.7 years) in a prospective, cross-sectional study. Exclusion criteria included aortic/heart disease and general MRI contra-indications. MRI of the aorta, heart and brain was performed for assessment of aortic PWV, as a marker of aortic stiffness, systolic LV function and mass, as well as for the presence of cerebral white matter hyperintensities (WMHs), microbleeds and lacunar infarcts. Multivariate linear or logistic regression was performed to analyse the association between aortic PWV and outcome parameters, with covariates defined as age, gender, mean arterial pressure, heart rate, BMI, smoking, DM duration and hypertension. Mean aortic PWV was 7.1 {+-} 2.5 m/s. Aortic PWV was independently associated with LV ejection fraction (ss= -0.406, P = 0.006), LV stroke volume (ss=-0.407, P = 0.001), LV cardiac output (ss= -0.458, P = 0.001), and with cerebral WMHs (P < 0.05). There were no independent associations between aortic stiffness and LV mass, cerebral microbleeds or lacunar infarcts. Aortic stiffness is independently associated with systolic LV function and cerebral WMHs in patients with type 1 DM. (orig.)

  14. The relationships between self-assessed habitual physical activity and non-invasive measures of cardiac autonomic modulation in young healthy volunteers.

    Science.gov (United States)

    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.

  15. Dual-enhancement cardiac computed tomography for assessing left atrial thrombus and pulmonary veins before radiofrequency catheter ablation for atrial fibrillation.

    Science.gov (United States)

    Hur, Jin; Pak, Hui-Nam; Kim, Young Jin; Lee, Hye-Jeong; Chang, Hyuk-Jae; Hong, Yoo Jin; Choi, Byoung Wook

    2013-07-15

    Noninvasive imaging that provides anatomic information while excluding intracardiac thrombus would be of significant clinical value for patients referred for catheter ablation of atrial fibrillation (AF). This study assessed the diagnostic performance of a dual-enhancement single-phase cardiac computed tomography (CT) protocol for thrombus and circulatory stasis detection in AF patients before catheter ablation. We studied 101 consecutive symptomatic AF patients (71 men and 30 women; mean age, 61.8 years) who were scheduled to have catheter ablation. All patients had undergone pre-AF ablation CT imaging and transesophageal echocardiography on the same day. CT was performed with prospective electrocardiographic gating, and scanning began 180 seconds after the test bolus. Mean left atrial appendage (LAA)/ascending aorta Hounsfield unit (HU) ratios were measured on CT images. Among the 101 patients, 9 thrombi and 18 spontaneous echo contrasts were detected by transesophageal echocardiography. The overall sensitivity, specificity, positive predictive value, and negative predictive value of CT for the detection of thrombi in the LAA were 89%, 100%, 100%, and 99%, respectively. The mean LAA/ascending aorta HU ratios were significantly different between thrombus and circulatory stasis (0.17 vs 0.33, p = 0.002). Dual-enhancement single-scan cardiac CT is a sensitive modality for detecting and differentiating LAA thrombus and circulatory stasis.

  16. Assessment of changes in liver blood flow after food intake—comparison of ICG clearance and echo-Doppler

    OpenAIRE

    Burggraaf, J; Schoemaker, H C; Cohen, A F

    1996-01-01

    Echo-Doppler measurements of portal venous blood flow in intrahepatic branches and indocyanine green (ICG) clearance after continuous i.v. infusion as measure for liver blood flow were compared to evaluate the increase in splanchnic blood flow after food intake. It was shown that both methods assessed the changes in flow in a similar manner. Changes in blood flow in intrahepatic portal vein branches measured with echo-Doppler adequately predicted the change in ICG concentrations. Hence, echo-...

  17. 4D phase contrast flow imaging for in-stent flow visualization and assessment of stent patency in peripheral vascular stents – A phantom study

    Energy Technology Data Exchange (ETDEWEB)

    Bunck, Alexander C., E-mail: alexander.bunck@uk-koeln.de [Department of Clinical Radiology, University Hospital Münster, Albert-Schweitzer-Campus 1, Building A1, 48149 Muenster (Germany); Department of Radiology, University Hospital Cologne, Kerpener Strasse 62, 50937 Cologne (Germany); Jüttner, Alena, E-mail: alenajuettner@gmx.de [Department of Clinical Radiology, University Hospital Münster, Albert-Schweitzer-Campus 1, Building A1, 48149 Muenster (Germany); Kröger, Jan Robert, E-mail: jr.kroeger@uni-muenster.de [Department of Clinical Radiology, University Hospital Münster, Albert-Schweitzer-Campus 1, Building A1, 48149 Muenster (Germany); Burg, Matthias C., E-mail: m_burg03@uni-muenster.de [Department of Clinical Radiology, University Hospital Münster, Albert-Schweitzer-Campus 1, Building A1, 48149 Muenster (Germany); Kugel, Harald, E-mail: kugel@uni-muenster.de [Department of Clinical Radiology, University Hospital Münster, Albert-Schweitzer-Campus 1, Building A1, 48149 Muenster (Germany); Niederstadt, Thomas, E-mail: tnieders@uni-muenster.de [Department of Clinical Radiology, University Hospital Münster, Albert-Schweitzer-Campus 1, Building A1, 48149 Muenster (Germany); Tiemann, Klaus, E-mail: Klaus.Tiemann@ukmuenster.de [Department of Cardiology and Angiology, University Hospital Münster, Albert-Schweitzer-Campus 1, Building A1, 48149 Muenster (Germany); Schnackenburg, Bernhard, E-mail: bernhard.schnackenburg@philips.com [Philips Medical Systems DMC GmbH, Röntgenstraße 24, 22335 Hamburg (Germany); Crelier, Gerard R., E-mail: crelier@biomed.ee.ethz.ch [Institute for Biomedical Engineering, ETH and University of Zurich, ETZ F 95, Gloriastrasse 35, 8092 Zurich (Switzerland); and others

    2012-09-15

    Purpose: 4D phase contrast flow imaging is increasingly used to study the hemodynamics in various vascular territories and pathologies. The aim of this study was to assess the feasibility and validity of MRI based 4D phase contrast flow imaging for the evaluation of in-stent blood flow in 17 commonly used peripheral stents. Materials and methods: 17 different peripheral stents were implanted into a MR compatible flow phantom. In-stent visibility, maximal velocity and flow visualization were assessed and estimates of in-stent patency obtained from 4D phase contrast flow data sets were compared to a conventional 3D contrast-enhanced magnetic resonance angiography (CE-MRA) as well as 2D PC flow measurements. Results: In all but 3 of the tested stents time-resolved 3D particle traces could be visualized inside the stent lumen. Quality of 4D flow visualization and CE-MRA images depended on stent type and stent orientation relative to the magnetic field. Compared to the visible lumen area determined by 3D CE-MRA, estimates of lumen patency derived from 4D flow measurements were significantly higher and less dependent on stent type. A higher number of stents could be assessed for in-stent patency by 4D phase contrast flow imaging (n = 14) than by 2D phase contrast flow imaging (n = 10). Conclusions: 4D phase contrast flow imaging in peripheral vascular stents is feasible and appears advantageous over conventional 3D contrast-enhanced MR angiography and 2D phase contrast flow imaging. It allows for in-stent flow visualization and flow quantification with varying quality depending on stent type.

  18. A review of environmental flow assessment: methodologies and application in the Qianhe River

    Science.gov (United States)

    Hao, C. F.; He, L. M.; Niu, C. W.; Jia, Y. W.

    2016-08-01

    Environmental flow is of great significance for maintenance of ecological services in the riverine ecosystem. The paper reviews present methodologies for environmental flow assessment on the basis of three classifications, including the Hydrological Index Methodologies, the Hydraulic Rating Methodologies and the Habitat Simulation Methodologies. Both advantages and disadvantages of each classification are fully analysed, as well as applicable conditions. Moreover, representative methods of different classifications are applied to prescribe environmental flow in the Qianhe River of north China with consideration of hydrological series, hydraulic characteristics and habitat suitability of targeted species. The results of environment flow by the Montana Method, Wetted Perimeter Method and Physical Habitat Simulation System are 1.23 m3/s, 2.07 m3/s and 0.52 m3/s for the Qianyang section in middle reach of the Qianhe River. In view of seasonal variation of the Qianhe River, the paper recommends 1.23 m3/s as the minimum runoff in the dry season and 2.07 m3/s in the wet season. For further improvement of environmental flow assessment, studies of quantitative correspondence relationship between each component of instream flow and its ecological functions of riverine ecosystem, and the development of Holistic Methodologies by combination of various methodologies and multi-disciplinary information have great potential.

  19. Flow cytometry of sputum: assessing inflammation and immune response elements in the bronchial airways**

    Science.gov (United States)

    Rationale: The evaluation of sputum leukocytes by flow cytometry is an opportunity to assess characteristics of cells residing in the central airways, yet it is hampered by certain inherent properties of sputum including mucus and large amounts of contaminating cells and debris. ...

  20. Comparative assessment of predictions in ungauged basins – Part 2: Flood and low flow studies

    Directory of Open Access Journals (Sweden)

    J. L. Salinas

    2013-07-01

    Full Text Available The objective of this paper is to assess the performance of methods that predict low flows and flood runoff in ungauged catchments. The aim is to learn from the similarities and differences between catchments in different places, and to interpret the differences in performance in terms of the underlying climate-landscape controls. The assessment is performed at two levels. The Level 1 assessment is a meta-analysis of 14 low flow prediction studies reported in the literature involving 3112 catchments, and 20 flood prediction studies involving 3023 catchments. The Level 2 assessment consists of a more focused and detailed analysis of individual basins from selected studies from Level 1 in terms of how the leave-one-out cross-validation performance depends on climate and catchment characteristics as well as on the regionalisation method. The results indicate that both flood and low flow predictions in ungauged catchments tend to be less accurate in arid than in humid climates and more accurate in large than in small catchments. There is also a tendency towards a somewhat lower performance of regressions than other methods in those studies that apply different methods in the same region, while geostatistical methods tend to perform better than other methods. Of the various flood regionalisation approaches, index methods show significantly lower performance in arid catchments than regression methods or geostatistical methods. For low flow regionalisation, regional regressions are generally better than global regressions.

  1. Assessment of cardiac autonomic functions by heart rate recovery, heart rate variability and QT dynamicity parameters in patients with acromegaly.

    Science.gov (United States)

    Dural, Muhammet; Kabakcı, Giray; Cınar, Neşe; Erbaş, Tomris; Canpolat, Uğur; Gürses, Kadri Murat; Tokgözoğlu, Lale; Oto, Ali; Kaya, Ergün Barış; Yorgun, Hikmet; Sahiner, Levent; Dağdelen, Selçuk; Aytemir, Kudret

    2014-04-01

    Cardiovascular complications are the most common causes of morbidity and mortality in acromegaly. However, there is little data regarding cardiac autonomic functions in these patients. Herein, we aimed to investigate several parameters of cardiac autonomic functions in patients with acromegaly compared to healthy subjects. We enrolled 20 newly diagnosed acromegalic patients (55% female, age:45.7 ± 12.6 years) and 32 age- and gender-matched healthy subjects. All participants underwent 24 h Holter recording. Heart rate recovery (HRR) indices were calculated by subtracting 1st, 2nd and 3rd minute heart rates from maximal heart rate. All patients underwent heart rate variability (HRV) and QT dynamicity analysis. Baseline characteristics were similar except diabetes mellitus and hypertension among groups. Mean HRR1 (29.2 ± 12.3 vs 42.6 ± 6.5, p = 0.001), HRR2 (43.5 ± 15.6 vs 61.1 ± 10.8, p = 0.001) and HRR3 (46.4 ± 16.2 vs 65.8 ± 9.8, p = 0.001) values were significantly higher in control group. HRV parameters as, SDNN [standard deviation of all NN intervals] (p = 0.001), SDANN [SD of the 5 min mean RR intervals] (p = 0.001), RMSSD [root square of successive differences in RR interval] (p = 0.001), PNN50 [proportion of differences in successive NN intervals >50 ms] (p = 0.001) and high-frequency [HF] (p = 0.001) were significantly decreased in patients with acromegaly; but low frequency [LF] (p = 0.046) and LF/HF (p = 0.001) were significantly higher in acromegaly patients. QTec (p = 0.009), QTac/RR slope (p = 0.017) and QTec/RR slope (p = 0.01) were significantly higher in patients with acromegaly. Additionally, there were significant negative correlation of disease duration with HRR2, HRR3, SDNN, PNN50, RMSSD, variability index. Our study results suggest that cardiac autonomic functions are impaired in patients with acromegaly. Further large scale studies are needed to exhibit the prognostic significance of impaired autonomic functions in patients with

  2. Cardiac Rehabilitation

    Science.gov (United States)

    ... your risk of future heart problems, and to improve your health and quality of life. Cardiac rehabilitation programs increase ... exercise routine at home or at a local gym. You may also continue to ... health concerns. Education about nutrition, lifestyle and weight loss ...

  3. Assessing Geomorphic and Vegetative Responses to Environmental Flows in the Willamette River Basin

    Science.gov (United States)

    Mangano, J.; Jones, K.; Wallick, R.; Bach, L.; Olson, M.; Bervid, H.

    2015-12-01

    On regulated rivers, restoring flow regimes is a process-based restoration approach that may strongly affect downstream ecosystems. Developing realistic flow targets with meaningful geomorphic and ecological benefits, however, is challenging. For instance, hydraulic, geomorphic and biological processes are affected by more than manipulating water release—sediment supply and transport conditions also require consideration. Also, funding and programmatic directives rarely require the monitoring necessary to adaptively manage environmental flow programs. Recent research in the Willamette River basin in support of the Sustainable Rivers Project (SRP) demonstrates how such a monitoring program can be implemented. At the reach scale, initial efforts have assessed geomorphic and vegetative changes in alluvial sections of the Middle Fork Willamette and McKenzie Rivers using repeat mapping from aerial photographs and flow analyses. Overall, both rivers are largely stable because of reduced discharge, bed-material supply and local revetments, but some reaches of the McKenzie River are more dynamic, perhaps reflecting greater inputs of sediment from unregulated tributaries and higher magnitude peak flows. Repeat, reach-scale mapping on the Middle Fork Willamette River shows that frequent bankfull flows are able to scour minimally vegetated gravel bars and sustain a patchwork of actively shifting bed-material sediment. Repeat mapping on the McKenzie River in summer 2015 will reveal insights about the geomorphic effectiveness of bankfull flows. At the site scale, monitoring at two bars in summer 2015 is linking streamflow with the establishment of black cottonwood. Lastly, a review of hydrographs from 2000-2015 and retrospectively applying stakeholder-defined flow targets showed substantial variability in meeting objectives for the timing and types of flows under traditional regulated conditions and the SRP. Altogether, these related efforts help link streamflow, geomorphic

  4. Assessment of spatial flow patterns in unsaturated sandy alluvial sediments using high- resolution GPR.

    Science.gov (United States)

    Haarder, E. B.; Looms, M. C.; Nielsen, L.; Jensen, K. H.

    2008-12-01

    of assessing unsaturated flow.

  5. Assessing uncertainties in remotely sensed lava flow emplacement - results from an indoor analog experiment

    Science.gov (United States)

    Pick, Leonie; Zakšek, Klemen; Lombardo, Valerio; Hort, Matthias

    2016-04-01

    Infrared satellite images are an easily accessible data source for monitoring the radiant power (RP) emitted from lava flows during effusive eruptions in close to real time. Although not necessary for RP estimations, lava temperature is a crucial parameter in the determination of the flow's convected heat. In conjunction with the flow's spatial extent it assists the identification of potentially threatened areas and thereby the overall lava inundation hazard assessment. The accurate determination of the flow's size and temperature is however afflicted with uncertainty as the lava occupies only a small fraction (wire temperatures corresponding to barely glowing (experiment 1), glowing (experiment 2) and strongly glowing (experiment 3) was confirmed. The deviation of the hotspot's pixel fraction yielded by the Dual-Band method from the theoretically calculated one was found to be within the expected limits given that the hotspot is larger than about 3 % of the pixel area, a resolution boundary most remotely sensed volcanic hotspots fall below.

  6. Real-time cardiac metabolism assessed with hyperpolarized [1-13C]acetate in a large-animal model

    DEFF Research Database (Denmark)

    Flori, Alessandra; Liserani, Matteo; Frijia, Francesca

    2015-01-01

    to 3 mmol. The Na[1-13C]acetate formulation was characterized by a liquid-state polarization of 14.2% and a T1Eff in vivo of 17.6 ± 1.7 s. In vivo Na[1-13C]acetate kinetics displayed a bimodal shape: [1-13C]acetyl carnitine (AcC) was detected in a slice covering the cardiac volume, and the signal of 13...... relaxation rate (r1). Our study proved the feasibility and the limitations of administration of large doses of hyperpolarized [1-13C]acetate to study the myocardial conversion of [1-13C]acetate in [1-13C]acetyl-carnitine generated by acetyltransferase in healthy pigs...

  7. A review of intraoperative goal-directed therapy using arterial waveform analysis for assessment of cardiac output.

    Science.gov (United States)

    Mehta, Neil; Fernandez-Bustamante, Ana; Seres, Tamas

    2014-01-01

    Increasing evidence shows that goal-directed hemodynamic management can improve outcomes in surgical and intensive care settings. Arterial waveform analysis is one of the different techniques used for guiding goal-directed therapy. Multiple proprietary systems have developed algorithms for obtaining cardiac output from an arterial waveform, including the FloTrac, LiDCO, and PiCCO systems. These systems vary in terms of how they analyze the arterial pressure waveform as well as their requirements for invasive line placement and calibration. Although small-scale clinical trials using these monitors show promising data, large-scale multicenter trials are still needed to better determine how intraoperative goal-directed therapy with arterial waveform analysis can improve patient outcomes. This review provides a comparative analysis of the different arterial waveform monitors for intraoperative goal-directed therapy.

  8. THE ASSESSMENT AND REDUCTION OF CARDIAC EVENTS RISK IN NONCARDIAC OPERATIONS: IS THERE A NEED FOR REVIEW OF RECOMMENDATIONS?

    Directory of Open Access Journals (Sweden)

    A. N. Sumin

    2013-01-01

    Full Text Available One of the pressing problems of modern cardiology is the cardiac complications risk evaluation and correction in noncardiac surgery. Recent international guidelines on this issue have focused on the pharmacological prevention of complications while reducing the preoperative examination and preventive revascularization. The reason for this experts position has been a series of studies DECREASE, performed in the Erasmus Medical Center (The Netherlands under the supervision of Professor D. Poldermans. However, this summer the results of these studies have found no scientific value because of the significant irregularities in their conduct. It makes to have a new look at the problem of perioperative medicine, to rethink the available scientific evidence. In this review we discussed in detail the use of beta-blockers in noncardiac surgery in view of new circumstances.

  9. THE ASSESSMENT AND REDUCTION OF CARDIAC EVENTS RISK IN NONCARDIAC OPERATIONS: IS THERE A NEED FOR REVIEW OF RECOMMENDATIONS?

    Directory of Open Access Journals (Sweden)

    A. N. Sumin

    2015-09-01

    Full Text Available One of the pressing problems of modern cardiology is the cardiac complications risk evaluation and correction in noncardiac surgery. Recent international guidelines on this issue have focused on the pharmacological prevention of complications while reducing the preoperative examination and preventive revascularization. The reason for this experts position has been a series of studies DECREASE, performed in the Erasmus Medical Center (The Netherlands under the supervision of Professor D. Poldermans. However, this summer the results of these studies have found no scientific value because of the significant irregularities in their conduct. It makes to have a new look at the problem of perioperative medicine, to rethink the available scientific evidence. In this review we discussed in detail the use of beta-blockers in noncardiac surgery in view of new circumstances.

  10. A Review of Intraoperative Goal-Directed Therapy Using Arterial Waveform Analysis for Assessment of Cardiac Output

    Directory of Open Access Journals (Sweden)

    Neil Mehta

    2014-01-01

    Full Text Available Increasing evidence shows that goal-directed hemodynamic management can improve outcomes in surgical and intensive care settings. Arterial waveform analysis is one of the different techniques used for guiding goal-directed therapy. Multiple proprietary systems have developed algorithms for obtaining cardiac output from an arterial waveform, including the FloTrac, LiDCO, and PiCCO systems. These systems vary in terms of how they analyze the arterial pressure waveform as well as their requirements for invasive line placement and calibration. Although small-scale clinical trials using these monitors show promising data, large-scale multicenter trials are still needed to better determine how intraoperative goal-directed therapy with arterial waveform analysis can improve patient outcomes. This review provides a comparative analysis of the different arterial waveform monitors for intraoperative goal-directed therapy.

  11. Cardiac tissue engineering: cell seeding, cultivation parameters, and tissue construct characterization.

    Science.gov (United States)

    Carrier, R L; Papadaki, M; Rupnick, M; Schoen, F J; Bursac, N; Langer, R; Freed, L E; Vunjak-Novakovic, G

    1999-09-01

    Cardiac tissue engineering has been motivated by the need to create functional tissue equivalents for scientific studies and cardiac tissue repair. We previously demonstrated that contractile cardiac cell-polymer constructs can be cultivated using isolated cells, 3-dimensional scaffolds, and bioreactors. In the present work, we examined the effects of (1) cell source (neonatal rat or embryonic chick), (2) initial cell seeding density, (3) cell seeding vessel, and (4) tissue culture vessel on the structure and composition of engineered cardiac muscle. Constructs seeded under well-mixed conditions with rat heart cells at a high initial density ((6-8) x 10(6) cells/polymer scaffold) maintained structural integrity and contained macroscopic contractile areas (approximately 20 mm(2)). Seeding in rotating vessels (laminar flow) rather than mixed flasks (turbulent flow) resulted in 23% higher seeding efficiency and 20% less cell damage as assessed by medium lactate dehydrogenase levels (p laminar and dynamic, yielded constructs with a more active, aerobic metabolism as compared to constructs cultured in mixed or static flasks. After 1-2 weeks of cultivation, tissue constructs expressed cardiac specific proteins and ultrastructural features and had approximately 2-6 times lower cellularity (p < 0.05) but similar metabolic activity per unit cell when compared to native cardiac tissue.

  12. [ASSESSING THE IMPACT OF CARDIAC DYSSYNCHRONY ON QUALITY OF LIFE IN PATIENTS WITH CHRONIC HEART FAILURE IN COMBINATION WITH TYPE 2 DIABETES MELLITUS].

    Science.gov (United States)

    Vlasenko, M A; Rodionova, Iu V; Lopin, D O

    2014-01-01

    In the article considers the influence of type 2 diabetes mellitus (T2DM) and cardiac dyssyn- chrony (DYS) on health-related quality of life (HRQoL) in patients with chronic heart failure (CHF) by means of Minnesota Living with Heart Failure Questionnaire (MLHFQ). It was found a negative impact of T2DM both on the overall assessment; and on the physical and emotional components of the HRQoL.in patients with CHE DYS also has a negative effect on HRQoL both in patients with isolated CHF and patients with CHF and concomitant T2DM, but its influence is mediated mainly by physical component. There were a number of factors that contribute to the DYS development in patients of studied groups identified, including the poor state of carbohydrate and lipid metabolism compensation, activation of systemic inflammation. It is expedient to study HRQoL to optimize therapeutic strategies in these patients.

  13. Assessment of the adequacy of bronchial stenting by flow-volume loops

    Energy Technology Data Exchange (ETDEWEB)

    McLaren, Clare A.; Roebuck, Derek J. [Great Ormond Street Hospital for Children, Department of Radiology, London (United Kingdom); Pigott, Nick; Elliott, Martin J. [Great Ormond Street Hospital for Children, Cardiothoracic Unit, London (United Kingdom); Dunne, Catherine [Great Ormond Street Hospital for Children, Department of Physiotherapy, London (United Kingdom)

    2006-08-15

    Airway compression is a common problem in children with certain forms of congenital heart disease. Although various surgical approaches are available to overcome this form of airway obstruction, internal stenting is necessary in a minority of patients. It can be difficult to assess the success of stenting at the time of the procedure, and the interval to successful extubation is usually used as an outcome measure. Measurement of relevant parameters of respiratory physiology with flow-volume and volume-pressure loops permits immediate quantitative assessment of the adequacy of stenting. A 3-month-old infant who underwent bronchial stenting and physiological assessment at the time of the procedure is described. (orig.)

  14. Catastrophic debris flows transformed from landslides in volcanic terrains : mobility, hazard assessment and mitigation strategies

    Science.gov (United States)

    Scott, Kevin M.; Macias, Jose Luis; Naranjo, Jose Antonio; Rodriguez, Sergio; McGeehin, John P.

    2001-01-01

    Communities in lowlands near volcanoes are vulnerable to significant volcanic flow hazards in addition to those associated directly with eruptions. The largest such risk is from debris flows beginning as volcanic landslides, with the potential to travel over 100 kilometers. Stratovolcanic edifices commonly are hydrothermal aquifers composed of unstable, altered rock forming steep slopes at high altitudes, and the terrain surrounding them is commonly mantled by readily mobilized, weathered airfall and ashflow deposits. We propose that volcano hazard assessments integrate the potential for unanticipated debris flows with, at active volcanoes, the greater but more predictable potential of magmatically triggered flows. This proposal reinforces the already powerful arguments for minimizing populations in potential flow pathways below both active and selected inactive volcanoes. It also addresses the potential for volcano flank collapse to occur with instability early in a magmatic episode, as well as the 'false-alarm problem'-the difficulty in evacuating the potential paths of these large mobile flows. Debris flows that transform from volcanic landslides, characterized by cohesive (muddy) deposits, create risk comparable to that of their syneruptive counterparts of snow and ice-melt origin, which yield noncohesive (granular) deposits, because: (1) Volcano collapses and the failures of airfall- and ashflow-mantled slopes commonly yield highly mobile debris flows as well as debris avalanches with limited runout potential. Runout potential of debris flows may increase several fold as their volumes enlarge beyond volcanoes through bulking (entrainment) of sediment. Through this mechanism, the runouts of even relatively small collapses at Cascade Range volcanoes, in the range of 0.1 to 0.2 cubic kilometers, can extend to populated lowlands. (2) Collapse is caused by a variety of triggers: tectonic and volcanic earthquakes, gravitational failure, hydrovolcanism, and

  15. PET and SPET tracers for mapping the cardiac nervous system

    Energy Technology Data Exchange (ETDEWEB)

    Langer, Oliver; Halldin, Christer [Department of Clinical Neuroscience, Psychiatry Section, Karolinska Institute, Karolinska Hospital, 17176 Stockholm (Sweden)

    2002-03-01

    The human cardiac nervous system consists of a sympathetic and a parasympathetic branch with (-)-norepinephrine and acetylcholine as the respective endogenous neurotransmitters. Dysfunction of the cardiac nervous system is implicated in various types of cardiac disease, such as heart failure, myocardial infarction and diabetic autonomic neuropathy. In vivo assessment of the distribution and function of cardiac sympathetic and parasympathetic neurones with positron emission tomography (PET) and single-photon emission tomography (SPET) can be achieved by means of a number of carbon-11-, fluorine-18-, bromine-76- and iodine-123-labelled tracer molecules. Available tracers for mapping sympathetic neurones can be divided into radiolabelled catecholamines, such as 6-[{sup 18}F]fluorodopamine, (-)-6-[{sup 18}F]fluoronorepinephrine and (-)-[{sup 11}C]epinephrine, and radiolabelled catecholamine analogues, such as [{sup 123}I]meta-iodobenzylguanidine, [{sup 11}C]meta-hydroxyephedrine, [{sup 18}F]fluorometaraminol, [{sup 11}C]phenylephrine and meta-[{sup 76}Br]bromobenzylguanidine. Resistance to metabolism by monoamine oxidase and catechol-O-methyl transferase simplifies the myocardial kinetics of the second group. Both groups of compounds are excellent agents for an overall assessment of sympathetic innervation. Biomathematical modelling of tracer kinetics is complicated by the complexity of the steps governing neuronal uptake, retention and release of these agents as well as by their high neuronal affinity, which leads to partial flow dependence of uptake. Mapping of cardiac parasympathetic neurones is limited by a low density and focal distribution pattern of these neurones in myocardium. Available tracers are derivatives of vesamicol, a molecule that binds to a receptor associated with the vesicular acetylcholine transporter. Compounds like (-)-[{sup 18}F]fluoroethoxybenzovesamicol display a high degree of non-specific binding in myocardium which restricts their utility

  16. Impact of pericardial adhesions on diastolic function as assessed by vortex formation time, a parameter of transmitral flow efficiency

    Directory of Open Access Journals (Sweden)

    Heys Jeffrey J

    2010-09-01

    Full Text Available Abstract Background Pericardial adhesions are a pathophysiological marker of constrictive pericarditis (CP, which impairs cardiac filling by limiting the total cardiac volume compliance and diastolic filling function. We studied diastolic transmitral flow efficiency as a new parameter of filling function in a pericardial adhesion animal model. We hypothesized that vortex formation time (VFT, an index of optimal efficient diastolic transmitral flow, is altered by patchy pericardial-epicardial adhesions. Methods In 8 open-chest pigs, the heart was exposed while preserving the pericardium. We experimentally simulated early pericardial constriction and patchy adhesions by instilling instant glue into the pericardial space and using pericardial-epicardial stitches. We studied left ventricular (LV function and characterized intraventricular blood flow with conventional and Doppler echocardiography at baseline and following the experimental intervention. Results Significant decreases in end-diastolic volume, ejection fraction, stroke volume, and late diastolic filling velocity reflected the effects of the pericardial adhesions. The mean VFT value decreased from 3.61 ± 0.47 to 2.26 ± 0.45 (P = 0.0002. Hemodynamic variables indicated the inhibiting effect of pericardial adhesion on both contraction (decrease in systolic blood pressure and +dP/dt decreased and relaxation (decrease in the magnitude of -dP/dt and prolongation of Tau function. Conclusion Patchy pericardial adhesions not only negatively impact LV mechanical functioning but the decrease of VFT from normal to suboptimal value suggests impairment of transmitral flow efficiency.

  17. Development of the Hydroecological Integrity Assessment Process for Determining Environmental Flows for New Jersey Streams

    Science.gov (United States)

    Kennen, Jonathan G.; Henriksen, James A.; Nieswand, Steven P.

    2007-01-01

    The natural flow regime paradigm and parallel stream ecological concepts and theories have established the benefits of maintaining or restoring the full range of natural hydrologic variation for physiochemical processes, biodiversity, and the evolutionary potential of aquatic and riparian communities. A synthesis of recent advances in hydroecological research coupled with stream classification has resulted in a new process to determine environmental flows and assess hydrologic alteration. This process has national and international applicability. It allows classification of streams into hydrologic stream classes and identification of a set of non-redundant and ecologically relevant hydrologic indices for 10 critical sub-components of flow. Three computer programs have been developed for implementing the Hydroecological Integrity Assessment Process (HIP): (1) the Hydrologic Indices Tool (HIT), which calculates 171 ecologically relevant hydrologic indices on the basis of daily-flow and peak-flow stream-gage data; (2) the New Jersey Hydrologic Assessment Tool (NJHAT), which can be used to establish a hydrologic baseline period, provide options for setting baseline environmental-flow standards, and compare past and proposed streamflow alterations; and (3) the New Jersey Stream Classification Tool (NJSCT), designed for placing unclassified streams into pre-defined stream classes. Biological and multivariate response models including principal-component, cluster, and discriminant-function analyses aided in the development of software and implementation of the HIP for New Jersey. A pilot effort is currently underway by the New Jersey Department of Environmental Protection in which the HIP is being used to evaluate the effects of past and proposed surface-water use, ground-water extraction, and land-use changes on stream ecosystems while determining the most effective way to integrate the process into ongoing regulatory programs. Ultimately, this scientifically defensible

  18. High-throughput tri-colour flow cytometry technique to assess Plasmodium falciparum parasitaemia in bioassays

    DEFF Research Database (Denmark)

    Tiendrebeogo, Regis W; Adu, Bright; Singh, Susheel K

    2014-01-01

    BACKGROUND: Unbiased flow cytometry-based methods have become the technique of choice in many laboratories for high-throughput, accurate assessments of malaria parasites in bioassays. A method to quantify live parasites based on mitotracker red CMXRos was recently described but consistent...... distinction of early ring stages of Plasmodium falciparum from uninfected red blood cells (uRBC) remains a challenge. METHODS: Here, a high-throughput, three-parameter (tri-colour) flow cytometry technique based on mitotracker red dye, the nucleic acid dye coriphosphine O (CPO) and the leucocyte marker CD45...

  19. Instream flow assessment and economic valuation: a survey of nonmarket benefits research

    Science.gov (United States)

    Douglas, Aaron J.; Johnson, Richard L.

    1993-01-01

    Instream flow benefits for United States streams and rivers have recently been investigated by a number of resource economists. These valuation efforts differ in scope, method, and quantitative results. An assessment and review of these valuation efforts is presented. The various sources of differences in non‐market values produced by these studies are explored in some detail. The considerable difficulty of producing estimates of instream flow benefits values that consider all of the pertinent policy and technical issues is delineated in various policy contexts. Evidence is presented that indicates that the considerable policy impact of recent research on this topic is justified despite considerable variation in the magnitude of the estimates.

  20. 75 FR 8412 - Office of New Reactors: Interim Staff Guidance on Assessing Ground Water Flow and Transport of...

    Science.gov (United States)

    2010-02-24

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Office of New Reactors: Interim Staff Guidance on Assessing Ground Water Flow and Transport of... Sections 2.4.12 and 2.4.13 regarding the assessment of ground water flow and transport of...

  1. Cardiac Calcification

    Directory of Open Access Journals (Sweden)

    Morteza Joorabian

    2011-05-01

    Full Text Available There is a spectrum of different types of cardiac"ncalcifications with the importance and significance"nof each type of cardiac calcification, especially"ncoronary artery calcification. Radiologic detection of"ncalcifications within the heart is quite common. The"namount of coronary artery calcification correlates"nwith the severity of coronary artery disease (CAD."nCalcification of the aortic or mitral valve may indicate"nhemodynamically significant valvular stenosis."nMyocardial calcification is a sign of prior infarction,"nwhile pericardial calcification is strongly associated"nwith constrictive pericarditis. A spectrum of different"ntypes of cardiac calcifications (linear, annular,"ncurvilinear,... could be seen in chest radiography and"nother imaging modalities. So a carful inspection for"ndetection and reorganization of these calcifications"nshould be necessary. Numerous modalities exist for"nidentifying coronary calcification, including plain"nradiography, fluoroscopy, intravascular ultrasound,"nMRI, echocardiography, and conventional, helical and"nelectron-beam CT (EBCT. Coronary calcifications"ndetected on EBCT or helical CT can be quantifie,"nand a total calcification score (Cardiac Calcification"nScoring may be calculated. In an asymptomatic"npopulation and/or patients with concomitant risk"nfactors like diabetes mellitus, determination of the"npresence of coronary calcifications identifies the"npatients at risk for future myocardial infarction and"ncoronary artery disease. In patients without coronary"ncalcifications, future cardiovascular events could"nbe excluded. Therefore, detecting and recognizing"ncalcification related to the heart on chest radiography"nand other imaging modalities such as fluoroscopy, CT"nand echocardiography may have important clinical"nimplications.

  2. Arterial aging and arterial disease : interplay between central hemodynamics, cardiac work, and organ flow-implications for CKD and cardiovascular disease

    NARCIS (Netherlands)

    London, Gerard; Covic, Adrian; Goldsmith, David; Wiecek, Andrzej; Suleymanlar, Gultekin; Ortiz, Alberto; Massy, Ziad; Lindholm, Bengt; Martinez-Castelao, Alberto; Fliser, Danilo; Agarwal, Rajiv; Jager, Kitty J.; Dekker, Friedo W.; Blankestijn, Peter J.; Zoccali, Carmine

    2011-01-01

    Cardiovascular disease is an important cause of morbidity and mortality in patients with chronic kidney disease (CKD) and end-stage renal disease (ESRD). All epidemiological studies have clearly shown that accelerated arterial and cardiac aging is characteristic of these populations. Arterial premat

  3. Myocardial bridging in a survivor of sudden cardiac near-death : Role of intracoronary Doppler flow measurements and angiography during dobutamine stress in the clinical evaluation

    NARCIS (Netherlands)

    Tio, RA; VanGelder, IC; Boonstra, PW; Crijns, HJGM

    1997-01-01

    Extensive myocardial bridging in the left anterior descending coronary artery was found in a 46 year old survivor of sudden cardiac near-death. Positron emission tomography and dobutamine stress echocardiography revealed ischaemia in the myocardium distal to the bridging. Spasm was excluded as cause

  4. Whole-heart cine MRI in a single breath-hold. A compressed sensing accelerated 3D acquisition technique for assessment of cardiac function

    Energy Technology Data Exchange (ETDEWEB)

    Wech, T.; Koestler, H. [Wuerzburg Univ. (Germany). Inst. of Radiology; Wuerzburg Univ. (Germany). Comprehensive Heart Failure Center; Pickl, W.; Tran-Gia, J.; Ritter, C.; Hahn, D. [Wuerzburg Univ. (Germany). Inst. of Radiology; Beer, M. [Wuerzburg Univ. (Germany). Inst. of Radiology; Graz Univ. (Austria). University Hospital Radiology

    2014-01-15

    simulated dataset and the in-vivo measurement highlights the great potential of the presented technique for an efficient assessment of cardiac functional parameters. (orig.)

  5. Were the May 2012 Emilia-Romagna earthquakes induced? A coupled flow-geomechanics modeling assessment

    Science.gov (United States)

    Juanes, R.; Jha, B.; Hager, B. H.; Shaw, J. H.; Plesch, A.; Astiz, L.; Dieterich, J. H.; Frohlich, C.

    2016-07-01

    Seismicity induced by fluid injection and withdrawal has emerged as a central element of the scientific discussion around subsurface technologies that tap into water and energy resources. Here we present the application of coupled flow-geomechanics simulation technology to the post mortem analysis of a sequence of damaging earthquakes (Mw = 6.0 and 5.8) in May 2012 near the Cavone oil field, in northern Italy. This sequence raised the question of whether these earthquakes might have been triggered by activities due to oil and gas production. Our analysis strongly suggests that the combined effects of fluid production and injection from the Cavone field were not a driver for the observed seismicity. More generally, our study illustrates that computational modeling of coupled flow and geomechanics permits the integration of geologic, seismotectonic, well log, fluid pressure and flow rate, and geodetic data and provides a promising approach for assessing and managing hazards associated with induced seismicity.

  6. An assessment of unstructured grid finite volume schemes for cold gas hypersonic flow calculations

    Directory of Open Access Journals (Sweden)

    João Luiz F. Azevedo

    2009-06-01

    Full Text Available A comparison of five different spatial discretization schemes is performed considering a typical high speed flow application. Flowfields are simulated using the 2-D Euler equations, discretized in a cell-centered finite volume procedure on unstructured triangular meshes. The algorithms studied include a central difference-type scheme, and 1st- and 2nd-order van Leer and Liou flux-vector splitting schemes. These methods are implemented in an efficient, edge-based, unstructured grid procedure which allows for adaptive mesh refinement based on flow property gradients. Details of the unstructured grid implementation of the methods are presented together with a discussion of the data structure and of the adaptive refinement strategy. The application of interest is the cold gas flow through a typical hypersonic inlet. Results for different entrance Mach numbers and mesh topologies are discussed in order to assess the comparative performance of the various spatial discretization schemes.

  7. A bioelectronic system for the monitoring of cardiac activity in mussels and crabs and its application in environmental assessments

    DEFF Research Database (Denmark)

    Kholodkevich, Sergey V.; Kuznetsova, Tatiana; Lehtonen, Kari

    The problem of developing early diagnostic tools for bioindication of the state of aquatic ecosystems and assessment of pollution level dangerous for the environment and biota is of great importance. The BEAST project of the Baltic Sea BONUS programme develops approaches for the assessment...

  8. The China Patient-Centred Evaluative Assessment of Cardiac Events (China PEACE)-Prospective Study of 3-Vessel Disease: rationale and design

    Science.gov (United States)

    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

  9. Risk assessment of debris flow in Yushu seismic area in China: a perspective for the reconstruction

    Science.gov (United States)

    Lan, H. X.; Li, L. P.; Zhang, Y. S.; Gao, X.; Liu, H. J.

    2013-11-01

    The 14 April 2010 Ms = 7.1 Yushu Earthquake (YE) had caused severe damage in the Jiegu township, the residential centre of Yushu Tibetan Autonomous Prefecture, Qinghai Province, China. In view of the fragile geological conditions after YE, risk assessment of secondary geohazards becomes an important concern for the reconstruction. A quantitative methodology was developed to assess the risk of debris flow by taking into account important intensity information. Debris flow scenarios were simulated with respect to rainfall events with 10, 50 and 100 yr returning period, respectively. The possible economic loss and fatalities caused by damage to buildings were assessed both in the settlement area and in the low hazard settlement area regarding the simulated debris flow events. Three modelled building types were adopted, i.e. hollow brick wood (HBW), hollow brick concrete (HBC) and reinforced concrete (RC) buildings. The results suggest that HBC structure achieves a good balance for the cost-benefit relationship compared with HBW and RC structures and thus could be an optimal choice for most of the new residential buildings in the Jiegu township. The low hazard boundary presents significant risk reduction efficiency in the 100 yr returning debris flow event. In addition, the societal risk for the settlement area is unacceptable when the 100 yr returning event occurs but reduces to ALARP (as low as reasonably practicable) level as the low hazard area is considered. Therefore, the low hazard area was highly recommended to be taken into account in the reconstruction. Yet, the societal risk might indeed approach an unacceptable level if one considers that YE has inevitably increased the occurrence frequency of debris flow. The quantitative results should be treated as a perspective for the reconstruction rather than precise numbers of future losses, owing to the complexity of the problem and the deficiency of data.

  10. Chronic upper airway obstruction: value of the flow volume loop examination in assessment and management.

    Science.gov (United States)

    Brookes, G B; Fairfax, A J

    1982-06-01

    Chronic obstructive lesions of the upper airways such as post-traumatic strictures, bilateral vocal cord paralysis and chronic inflammatory foci are uncommon. The functional assessment of the severity and character of an obstruction is important both for diagnosis and management, and may also allow evaluation of the efficacy of medical and surgical treatment. There are limitations of simple spirometric pulmonary function tests, which are evident when assessing upper airways obstruction. The flow volume loop is a graphic recording of airflow during maximal respiration and expiration at different lung volumes, and may be affected in a characteristic way by alterations in the airway resistance. Three unusual cases of chronic upper airway obstruction are presented which illustrate the value of the flow volume loop examination in their management.

  11. Hazards Assessment of Regional Debris Flows Based on Geographic Information Science

    Institute of Scientific and Technical Information of China (English)

    JIANG Xiaobo; GUI Peng

    2007-01-01

    Supported by the spatial analysis feature of geographic information science and assessment model of regional debris flows, hazards degrees of the debris flows in the Upper Yangtze River Watershed (UYRW) are divided into five grades based on grid cell. The area of no danger, light danger, medium danger, severe danger and extreme severe danger regions respectively are 278 000, 288 000, 217 000, 127 000, 15 000 km2. Furthermore, the counties in the UYRW are classified into four classes based on the hazards degrees in each county. The number of severe danger, medium danger, light danger and no danger counties respectively are 49, 82, 77 and 105. The assessment results will be provided for the hazards forecasting and mitigation in the UYRW and ongoing regionalization of Main Function Regions in China as data and technique framework.

  12. Quantitative assessment of regional myocardial blood flow with thallium-201 and SPECT.

    Science.gov (United States)

    Iida, H; Eberl, S

    1998-01-01

    Thallium-201 has been used extensively as a myocardial perfusion agent and to assess myocardial viability. Unlike other 99mTc-labeled agents such as 99mTc-sestamibi and 99mTc-tetrofosmine, the regional concentration of 201Tl varies with time, and its kinetics make it a potential candidate for estimating absolute physiologic parameters with kinetic model analysis. This article outlines a strategy for quantitative assessment of regional myocardial blood flow in man using 201Tl and dynamic single photon emission computed tomography (SPECT). Quantitatively accurate SPECT images that are proportional to the true radioactivity distribution are prerequisites for model-based kinetic analysis. Our technique for quantitative SPECT includes ordered-subset maximum likelihood-expectation maximization (ML-EM) reconstruction with transmission data-based attenuation correction and transmission-dependent convolution subtraction scatter correction. A three-compartment model was found to reproduce the observed regional time-activity curves well, and dog experiments demonstrated that influx rate constant (K1) values estimated from the dynamic SPECT data correlated well with absolute myocardial blood flow determined by in vitro microspheres for a physiologically wide range of flows. Several possible strategies for simplifying the study procedures, without compromising accuracy, are also presented, which should make absolute quantitation of regional myocardial blood flow feasible using 201Tl and a conventional SPECT camera in a clinical setting.

  13. Debris-flow hazard assessment at regional scale by combining susceptibility mapping and radar rainfall

    Directory of Open Access Journals (Sweden)

    M. Berenguer

    2014-10-01

    Full Text Available This work presents a technique for debris flow (DF hazard assessment able to be used in the framework of DF early warning systems at regional scale. The developed system is applied at subbasin scale and is based on the concepts of fuzzy logic to combine two ingredients: (i DF subbasin susceptibility assessment based on geomorphological variables, and (ii the magnitude of the rainfall situation as depicted from radar rainfall estimates. The output of the developed technique is a three-class hazard level ("low", "moderate" and "high" in each subbasin when a new radar rainfall map is available. The developed technique has been applied in a domain in the Eastern Pyrenees (Spain from May to October 2010. The estimated hazard level stayed "low" during the entire period in 20% of the subbasins, while, in the most susceptible subbasins, the hazard level was at least moderate for up to10 days. Quantitative evaluation of the estimated hazard level was possible in a subbasin where debris flows were monitored during the analysis period. The technique was able to identify the 3 events observed in the catchment (1 debris flow and 2 hyperconcentrated flow events and produced no false alarm.

  14. Non invasive blood flow assessment in diabetic foot ulcer using laser speckle contrast imaging technique

    Science.gov (United States)

    Jayanthy, A. K.; Sujatha, N.; Reddy, M. Ramasubba; Narayanamoorthy, V. B.

    2014-03-01

    Measuring microcirculatory tissue blood perfusion is of interest for both clinicians and researchers in a wide range of applications and can provide essential information of the progress of treatment of certain diseases which causes either an increased or decreased blood flow. Diabetic ulcer associated with alterations in tissue blood flow is the most common cause of non-traumatic lower extremity amputations. A technique which can detect the onset of ulcer and provide essential information on the progress of the treatment of ulcer would be of great help to the clinicians. A noninvasive, noncontact and whole field laser speckle contrast imaging (LSCI) technique has been described in this paper which is used to assess the changes in blood flow in diabetic ulcer affected areas of the foot. The blood flow assessment at the wound site can provide critical information on the efficiency and progress of the treatment given to the diabetic ulcer subjects. The technique may also potentially fulfill a significant need in diabetic foot ulcer screening and management.

  15. Rheoencephalography (REG) as a Non-Invasive Monitoring Alternative for the Assessment of Brain Blood Flow

    Science.gov (United States)

    2004-09-01

    bioimpedance (rheoencephalography - REG) measurement as a non-invasive, continuous method for assessing the status of cerebral blood flow (CBF) in combat...Dunster KR, Colditz PB, Ward LC. Noninvasive measurement of cerebral bioimpedance for detection of cerebral edema in the neonatal piglet. Brain Res...REG measurements and DC impedance (Ro) were recorded simultaneously on a portable IBM compatible computer using CODAS (DATAQ, Inc., Akron, OH) data

  16. Development of substance flow based Life Cycle Assessment tool for sewage sludge treatment and disposal

    DEFF Research Database (Denmark)

    Yoshida, Hiroko; Clavreul, Julie; Scheutz, Charlotte;

    Life Cycle Assessment (LCA) is a method to quantify environmental impacts of products or systems. It is often done by correlating material and energy demands with certain input characteristics. An attempt was made to evaluate the robustness of the substance flow based LCA for wastewater and sludge...... treatment processes correlate sufficiently with the solids content of wastewater influent, while energy use correlates with the total input volume. However, the correlations appeared to be stronger when individual treatment processes were separately analysed....

  17. Flow cytometry for the assessment of animal sperm integrity and functionality: state of the art

    Institute of Scientific and Technical Information of China (English)

    Md.Sharoare Hossain; Anders Johannisson; Margareta Wallgren; Szabolcs Nagy; Amanda Pimenta Siqueira; Heriberto Rodriguez-Martinez

    2011-01-01

    Flow cytometry is now a recognized methodology within animal spermatology, and has moved from being a research tool to become routine in the assessment of animal semen destined to breeding. The availability of 'bench-top' flow cytometers and of newer and versatile markers for cell structure and function had allowed the instrumentation to measure more sperm parameters, from viability to reactiveness when exposed to exogenous stimuli, and to increase our capabilities to sort spermatozoa for potential fertilizing capacity, or chromosomal sex. The present review summarizes the state of the art regarding flow cytometry applied to animal andrology, albeit keeping an open comparative intent. It critically evaluates the present and future capabilities of flow cytometry for the diagnostics of potential fertility and for the development of current reproductive technologies such as sperm freezing, sperm selection and sperm sorting. The flow cytometry methods will probably further revolutionize our understanding of the sperm physiology and their functionality, and will undoubtedly extend its application in isolating many uncharacterized features of spermatozoa. However, continuous follow-up of the methods is a necessity owing to technical developments and the complexity of mapping spermatozoa.

  18. The decrease of cardiac chamber volumes and output during positive-pressure ventilation

    DEFF Research Database (Denmark)

    Kristensen, Kasper Kyhl; Ahtarovski, Kiril Aleksov; Iversen, Kasper

    2013-01-01

    the effect of PPV on the central circulation by studying cardiac chamber volumes with cardiac magnetic resonance imaging (CMR). We hypothesized that PPV lowers cardiac output (CO) mainly via the Frank-Starling relationship. In 18 healthy volunteers, cardiac chamber volumes and flow in aorta and the pulmonary...

  19. Assessment of right ventricular oxidative metabolism by PET in patients with idiopathic dilated cardiomyopathy undergoing cardiac resynchronisation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Knuuti, Juhani; Naum, Alexandru; Stolen, Kira Q.; Kalliokoski, Riikka [University of Turku, Turku PET Centre, P.O. Box 52, Turku (Finland); Sundell, Jan [University of Turku, Turku PET Centre, P.O. Box 52, Turku (Finland); University of Turku, Department of Medicine, Turku (Finland); Engblom, Erik; Koistinen, Juhani; Airaksinen, K.E. Juhani [University of Turku, Department of Medicine, Turku (Finland); Ylitalo, Antti [Satakunta Central Hospital, Department of Medicine, Pori (Finland); Nekolla, Stephan G. [Klinikum rechts der Isar der Technischen Universitaet Muenchen, Klinik und Poliklinik fuer Nuklearmedizin, Munich (Germany); Bax, K.E. Jeroen J. [Leiden University, Department of Cardiology, Leiden (Netherlands)

    2004-12-01

    Right ventricular (RV) performance is known to have prognostic value in patients with congestive heart failure (CHF). Cardiac resynchronisation therapy (CRT) has been found to enhance left ventricular (LV) energetics and metabolic reserve in patients with heart failure. The interplay between the LV and RV may play an important role in CRT response. The purpose of the study was to investigate RV oxidative metabolism, metabolic reserve and the effects of CRT in patients with CHF and left bundle brach block. In addition, the role of the RV in the response to CRT was evaluated. Ten patients with idiopathic dilated cardiomyopathy who had undergone implantation of a biventricular pacemaker 8{+-}5 months earlier were studied under two conditions: CRT ON and after CRT had been switched OFF for 24 h. Oxidative metabolism was measured using [{sup 11}C]acetate positron emission tomography (K{sub mono}). The measurements were performed at rest and during dobutamine-induced stress (5 {mu}g/kg per minute). LV performance and interventricular mechanical delay (interventricular asynchrony) were measured using echocardiography. CRT had no effect on RV K{sub mono} at rest (ON: 0.052{+-}0.014, OFF: 0.047{+-}0.018, NS). Dobutamine-induced stress increased RV K{sub mono} significantly under both conditions but oxidative metabolism was more enhanced when CRT was ON (0.076{+-}0.026 vs 0.065{+-}0.027, p=0.003). CRT shortened interventricular delay significantly (45{+-}33 vs 19{+-}35 ms, p=0.05). In five patients the response to CRT was striking (32% increase in mean LV stroke volume, range 18-36%), while in the other five patients no response was observed (mean change +2%, range -6% to +4%). RV K{sub mono} and LV stroke volume response to CRT correlated inversely (r=-0.66, p=0.034). None of the other measured parameters, including all LV parameters and electromechanical parameters, were associated with the response to CRT. In responders, RV K{sub mono} with CRT OFF was significantly lower

  20. Gene flow in Prunus species in the context of novel trait risk assessment.

    Science.gov (United States)

    Cici, S Zahra H; Van Acker, Rene C

    2010-01-01

    Prunus species are important commercial fruit (plums, apricot, peach and cherries), nut (almond) and ornamental trees cultivated broadly worldwide. This review compiles information from available literature on Prunus species in regard to gene flow and hybridization within this complex of species. The review serves as a resource for environmental risk assessment related to pollen mediated gene flow and the release of transgenic Prunus. It reveals that Prunus species, especially plums and cherries show high potential for transgene flow. A range of characteristics including; genetic diversity, genetic bridging capacity, inter- and intra-specific genetic compatibility, self sterility (in most species), high frequency of open pollination, insect assisted pollination, perennial nature, complex phenotypic architecture (canopy height, heterogeneous crown, number of flowers produced in an individual plant), tendency to escape from cultivation, and the existence of ornamental and road side Prunus species suggest that there is a tremendous and complicated ability for pollen mediated gene movement among Prunus species. Ploidy differences among Prunus species do not necessarily provide genetic segregation. The characteristics of Prunu s species highlight the complexity of maintaining coexistence between GM and non-GM Prunus if there were commercial production of GM Prunus species. The results of this review suggest that the commercialization of one GM Prunus species can create coexistence issues for commercial non-GM Prunus production. Despite advances in molecular markers and genetic analysis in agroecology, there remains limited information on the ecological diversity, metapopulation nature, population dynamics, and direct measures of gene flow among different subgenera represented in the Prunus genus. Robust environmental impact, biosafety and coexistence assessments for GM Prunus species will require better understanding of the mechanisms of gene flow and hybridization

  1. Assessment model validity document. NAMMU: A program for calculating groundwater flow and transport through porous media

    Energy Technology Data Exchange (ETDEWEB)

    Cliffe, K.A.; Morris, S.T.; Porter, J.D. [AEA Technology, Harwell (United Kingdom)

    1998-05-01

    NAMMU is a computer program for modelling groundwater flow and transport through porous media. This document provides an overview of the use of the program for geosphere modelling in performance assessment calculations and gives a detailed description of the program itself. The aim of the document is to give an indication of the grounds for having confidence in NAMMU as a performance assessment tool. In order to achieve this the following topics are discussed. The basic premises of the assessment approach and the purpose of and nature of the calculations that can be undertaken using NAMMU are outlined. The concepts of the validation of models and the considerations that can lead to increased confidence in models are described. The physical processes that can be modelled using NAMMU and the mathematical models and numerical techniques that are used to represent them are discussed in some detail. Finally, the grounds that would lead one to have confidence that NAMMU is fit for purpose are summarised.

  2. Assessment on alien herbicide-resistant gene flow among crucifers by sexual compatibility

    Institute of Scientific and Technical Information of China (English)

    ZHAO Xiangxiang; LU Weiping; QI Cunkou; PU Huiming; XIA Qiuxia; LU Dalei; LIU Geshan; WANG Youping

    2005-01-01

    Cross-pollination and high cross-compatibility are frequently found in many cruciferous plants, which implies that there might be potential risk of alien gene flow among crucifers. In this work, the alien glyphosate-resistant gene flow between GM (Genetically modified) rapeseed variety Q3 (Brassica napus) and 6 varieties from 5 cruciferous species was assessed by sexual compatibility through aniline blue fluorescence observation, manual cross, mentor pollination with the mixture pollen and DNA identification. The results indicated that the compatibility indices of two B. napus varieties, B. juncea var. multiceps Tsen et Lee and Chinese cabbage (B. chinensis) (as female) with Q3 (as male) were 16.15, 12.77, 2.345 and 0.85, respectively. F1 plants were examined by PCR and all of these samples were confirmed as positive. Crossing between Orychophragmus violaceus, Descurainia sophia (as female) and Q3 (as male) expressed high cross-incompatibility. Fluorescence microscope observation indicated that growing of pollen tube terminated at the upper 1/3 part of the style of O. violaceus and on the stigma surface of D. sophia. The mentor plants were further analyzed by PCR and all were shown to be negative. Under the neighboring growth and natural pollination conditions, the rates of gene flow to two B. napus varieties were 2.3278% and 2.1487%, respectively, B. juncea var. multiceps Tsen et Lee and Chinese cabbage were 1.0157% and 0.9236%, respectively. No gene flow was observed in O. violaceus and D. sophia. Frequency of gene flow was highly correlated with sexual compatibility. Due to possible alien gene flow among crucifers, special consideration and care should be taken to grow GM rapeseed.

  3. A three-pillar approach to assessing climate impacts on low flows

    Directory of Open Access Journals (Sweden)

    G. Laaha

    2015-12-01

    Full Text Available The objective of this paper is to present a new strategy for assessing climate impacts on low flows and droughts. The strategy is termed a three-pillar approach as it combines different sources of information. The first pillar, trend extrapolation, exploits the temporal patterns of observed low flows and extends them into the future. The second pillar, rainfall–runoff projections uses precipitation and temperature scenarios from climate models as an input to rainfall–runoff models to project future low flows. The third pillar, stochastic projections, exploits the temporal patterns of observed precipitation and air temperature and extends them into the future to drive rainfall–runoff projections. These pieces of information are combined by expert judgement based on a synoptic view of data and model outputs, taking the respective uncertainties of the methods into account. The viability of the approach is demonstrated for four example catchments from Austria that represent typical climate conditions in Central Europe. The projections differ in terms of their signs and magnitudes. The degree to which the methods agree depends on the regional climate and the dominant low flow seasonality. In the Alpine region where winter low flows dominate, trend projections and climate scenarios yield consistent projections of increasing low flows, although of different magnitudes. In the region north of the Alps, consistently small changes are projected by all methods. In the regions in the South and Southeast, more pronounced and mostly decreasing trends are projected but there is disagreement in the magnitudes of the projected changes. These results suggest that conclusions drawn from only one pillar of information would be highly uncertain. The three-pillar approach offers a systematic framework of combining different sources of information aiming at more robust projections than obtained from each pillar alone.

  4. Cardiac Vagal Regulation and Early Peer Status

    Science.gov (United States)

    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…

  5. Experimental Assessment of the Two-Phase Flow in a Large Inclined Channel

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Thanh Hung; Song, Ki Won; Revankar, Shripad T; Park, Hyun Sun [Pohang University of Science and Technology, Pohang (Korea, Republic of)

    2014-10-15

    In order to assess the cooling performance of the core catcher system, a model facility has been constructed in POSTECH using scaling analysis. This facility consists of horizontal, inclined and vertical section. To investigate the flow parameters in each section, the instrumentation is developed to measure two-phase characteristics such as local void fraction, bubble velocity and bubble size. To date, there has been a considerable amount of research conducted on the internal structure of two-phase flow in pipe. However, the number of attempts made on the experiment regarding large inclined channels has been still limited. One of the reasons for this lack of data is the difficulty in constructing experimental facility. In this paper, the parameters of the flow in the inclined section are presented. The inclined channel is 10 degree from the horizontal with the rectangular cross section of 300 cm{sup 2}. The distributions of local parameters are evaluated through the data of double sensor conductivity probes installed at different locations along the inclined section. The data sets of the structure of two-phase flow in an inclined large channel was acquired. The air was injected through the metal foam installed on the top surface wall of the inclined section. Water level was kept below the top of the inclined section so the amount of water was fixed during the experiment. 9 probes set up at the different locations to get the data of local two-phase parameters. The measurement at each location was conducted in 5 minutes to determine the mean value of each parameter. The result of local void fraction profiles at different locations indicates that the void distribution primarily changes along the height of the inclined section. The slug flow occurs in the channel which results in most bubbles attached to the top surface wall. This fact explains the high local void fraction near the top wall and its rapid decline towards the bottom wall of the inclined section. The

  6. Pesticide Flow Analysis to Assess Human Exposure in Greenhouse Flower Production in Colombia

    Directory of Open Access Journals (Sweden)

    Claudia R. Binder

    2013-03-01

    Full Text Available Human exposure assessment tools represent a means for understanding human exposure to pesticides in agricultural activities and managing possible health risks. This paper presents a pesticide flow analysis modeling approach developed to assess human exposure to pesticide use in greenhouse flower crops in Colombia, focusing on dermal and inhalation exposure. This approach is based on the material flow analysis methodology. The transfer coefficients were obtained using the whole body dosimetry method for dermal exposure and the button personal inhalable aerosol sampler for inhalation exposure, using the tracer uranine as a pesticide surrogate. The case study was a greenhouse rose farm in the Bogota Plateau in Colombia. The approach was applied to estimate the exposure to pesticides such as mancozeb, carbendazim, propamocarb hydrochloride, fosetyl, carboxin, thiram, dimethomorph and mandipropamide. We found dermal absorption estimations close to the AOEL reference values for the pesticides carbendazim, mancozeb, thiram and mandipropamide during the study period. In addition, high values of dermal exposure were found on the forearms, hands, chest and legs of study participants, indicating weaknesses in the overlapping areas of the personal protective equipment parts. These results show how the material flow analysis methodology can be applied in the field of human exposure for early recognition of the dispersion of pesticides and support the development of measures to improve operational safety during pesticide management. Furthermore, the model makes it possible to identify the status quo of the health risk faced by workers in the study area.

  7. Assessing flow regime alterations in a temporary river – the River Celone case study

    Directory of Open Access Journals (Sweden)

    De Girolamo Anna Maria

    2015-09-01

    Full Text Available In this paper, we present an approach to evaluate the hydrological alterations of a temporary river. In these rivers, it is expected that anthropogenic pressures largely modify low-flow components of the flow regime with consequences for aquatic habitat and diversity in invertebrate species. First, by using a simple hydrological index (IARI river segments of the Celone stream (southern Italy whose hydrological regime is significantly influenced by anthropogenic activities have been identified. Hydrological alteration has been further classified through the analysis of two metrics: the degree (Mf and the predictability of dry flow conditions (Sd6. Measured streamflow data were used to calculate the metrics in present conditions (impacted. Given the lack of data from pristine conditions, simulated streamflow time series were used to calculate the metrics in reference conditions. The Soil and Water Assessment Tool (SWAT model was used to estimate daily natural streamflow. Hydrological alterations associated with water abstractions, point discharges and the presence of a reservoir were assessed by comparing the metrics (Mf, Sd6 before and after the impacts. The results show that the hydrological regime of the river segment located in the upper part of the basin is slightly altered, while the regime of the river segment downstream of the reservoir is heavily altered. This approach is intended for use with ecological metrics in defining the water quality status and in planning streamflow management activities.

  8. An Empirical Assessment of Transgene Flow from a Bt Transgenic Poplar Plantation.

    Science.gov (United States)

    Hu, Jianjun; Zhang, Jin; Chen, Xingling; Lv, Jinhui; Jia, Huixia; Zhao, Shutang; Lu, Mengzhu

    2017-01-01

    To assess the possible impact of transgenic poplar plantations on the ecosystem, we analyzed the frequency and distance of gene flow from a mature male transgenic Populus nigra plantation carrying the Bacillus thuringiensis toxin gene (Bt poplar) and the survival of Bt poplar seeds. The resultant Bt poplar seeds occurred at a frequency of ~0.15% at 0 m to ~0.02% at 500 m from the Bt poplar plantation. The germination of Bt poplar seeds diminished within three weeks in the field (germination rate from 68% to 0%) compared to 48% after three weeks of storage at 4°C. The survival rate of seedlings in the field was 0% without any treatment but increased to 1.7% under the addition of four treatments (cleaning and trimming, watering, weeding, and covering with plastic film to maintain moisture) after being seeded in the field for eight weeks. The results of this study indicate that gene flow originating from the Bt poplar plantation occurred at an extremely low level through pollen or seeds under natural conditions. This study provides first-hand field data on the extent of transgene flow in poplar plantations and offers guidance for the risk assessment of transgenic poplar plantations.

  9. Pesticide flow analysis to assess human exposure in greenhouse flower production in Colombia.

    Science.gov (United States)

    Lesmes-Fabian, Camilo; Binder, Claudia R

    2013-03-25

    Human exposure assessment tools represent a means for understanding human exposure to pesticides in agricultural activities and managing possible health risks. This paper presents a pesticide flow analysis modeling approach developed to assess human exposure to pesticide use in greenhouse flower crops in Colombia, focusing on dermal and inhalation exposure. This approach is based on the material flow analysis methodology. The transfer coefficients were obtained using the whole body dosimetry method for dermal exposure and the button personal inhalable aerosol sampler for inhalation exposure, using the tracer uranine as a pesticide surrogate. The case study was a greenhouse rose farm in the Bogota Plateau in Colombia. The approach was applied to estimate the exposure to pesticides such as mancozeb, carbendazim, propamocarb hydrochloride, fosetyl, carboxin, thiram, dimethomorph and mandipropamide. We found dermal absorption estimations close to the AOEL reference values for the pesticides carbendazim, mancozeb, thiram and mandipropamide during the study period. In addition, high values of dermal exposure were found on the forearms, hands, chest and legs of study participants, indicating weaknesses in the overlapping areas of the personal protective equipment parts. These results show how the material flow analysis methodology can be applied in the field of human exposure for early recognition of the dispersion of pesticides and support the development of measures to improve operational safety during pesticide management. Furthermore, the model makes it possible to identify the status quo of the health risk faced by workers in the study area.

  10. Cardiac imaging. A multimodality approach

    Energy Technology Data Exchange (ETDEWEB)

    Thelen, Manfred [Johannes Gutenberg University Hospital, Mainz (Germany); Erbel, Raimund [University Hospital Essen (Germany). Dept. of Cardiology; Kreitner, Karl-Friedrich [Johannes Gutenberg University Hospital, Mainz (Germany). Clinic and Polyclinic for Diagnostic and Interventional Radiology; Barkhausen, Joerg (eds.) [University Hospital Schleswig-Holstein, Luebeck (Germany). Dept. of Radiology and Nuclear Medicine

    2009-07-01

    An excellent atlas on modern diagnostic imaging of the heart Written by an interdisciplinary team of experts, Cardiac Imaging: A Multimodality Approach features an in-depth introduction to all current imaging modalities for the diagnostic assessment of the heart as well as a clinical overview of cardiac diseases and main indications for cardiac imaging. With a particular emphasis on CT and MRI, the first part of the atlas also covers conventional radiography, echocardiography, angiography and nuclear medicine imaging. Leading specialists demonstrate the latest advances in the field, and compare the strengths and weaknesses of each modality. The book's second part features clinical chapters on heart defects, endocarditis, coronary heart disease, cardiomyopathies, myocarditis, cardiac tumors, pericardial diseases, pulmonary vascular diseases, and diseases of the thoracic aorta. The authors address anatomy, pathophysiology, and clinical features, and evaluate the various diagnostic options. Key features: - Highly regarded experts in cardiology and radiology off er image-based teaching of the latest techniques - Readers learn how to decide which modality to use for which indication - Visually highlighted tables and essential points allow for easy navigation through the text - More than 600 outstanding images show up-to-date technology and current imaging protocols Cardiac Imaging: A Multimodality Approach is a must-have desk reference for cardiologists and radiologists in practice, as well as a study guide for residents in both fields. It will also appeal to cardiac surgeons, general practitioners, and medical physicists with a special interest in imaging of the heart. (orig.)

  11. Flow cytometric scoring of micronucleated erythrocytes: an efficient platform for assessing in vivo cytogenetic damage.

    Science.gov (United States)

    Dertinger, Stephen D; Torous, Dorothea K; Hayashi, Makoto; MacGregor, James T

    2011-01-01

    The relative simplicity of the micronucleated erythrocyte endpoint has made it amenable to automated scoring approaches. Flow cytometry is one such scoring platform that has been employed successfully. This review describes the evolution and properties of flow cytometry-based scoring of micronucleated erythrocytes. The methodology has become widely applied to rodent blood specimens and the high throughput nature of the technology provides a number of advantages over manual microscopic scoring. For instance, the ability to efficiently survey many dose levels and many more cells per specimen relative to microscopy benefits studies that are designed to identify no observable effect levels or lowest observable effect levels. Furthermore, flow cytometry makes it practical to study species with low spontaneous reticulocyte (RET) counts and micronucleus (MN) frequencies, thereby facilitating integration of blood-based micronucleated reticulocyte (MN-RET) frequency measurements into experiments conducted across species of toxicological interest. This capability enhances genotoxicity assessments that have historically been made in dedicated MN tests performed in one species. Importantly, the feasibility of using MN-RET frequencies in blood from humans as an index of genetic damage in bone marrow opens a critical area of application that had not been practical previously. We conclude with recommendations for additional work that is needed to more fully realise the potential of flow cytometric in vivo MN scoring.

  12. Resource efficiency of urban sanitation systems. A comparative assessment using material and energy flow analysis

    Energy Technology Data Exchange (ETDEWEB)

    Meinzinger, Franziska

    2010-07-01

    Within the framework of sustainable development it is important to find ways of reducing natural resource consumption and to change towards closed-loop management. As in many other spheres increased resource efficiency has also become an important issue in sanitation. Particularly nutrient recovery for agriculture, increased energy-efficiency and saving of natural water resources, can make a contribution to more resource efficient sanitation systems. To assess the resource efficiency of alternative developments a systems perspective is required. The present study applies a combined cost, energy and material flow analysis (ceMFA) as a system analysis method to assess the resource efficiency of urban sanitation systems. This includes the discussion of relevant criteria and assessment methods. The main focus of this thesis is the comparative assessment of different systems, based on two case studies; Hamburg in Germany and Arba Minch in Ethiopia. A range of possible system developments including source separation (e.g. diversion of urine or blackwater) is defined and compared with the current situation as a reference system. The assessment is carried out using computer simulations based on model equations. The model equations not only integrate mass and nutrient flows, but also the energy and cost balances of the different systems. In order to assess the impact of different assumptions and calculation parameters, sensitivity analyses and parameter variations complete the calculations. Based on the simulations, following general conclusions can be drawn: None of the systems show an overall benefit with regard to all investigated criteria, namely nutrients, energy, water and costs. Yet, the results of the system analysis can be used as basis for decision making if a case-related weighting is introduced. The systems show varying potential for the recovery of nutrients from (source separated) wastewater flows. For the case study of Hamburg up to 29% of the mineral

  13. Cardiac hybrid imaging

    Energy Technology Data Exchange (ETDEWEB)

    Gaemperli, Oliver [University Hospital Zurich, Cardiac Imaging, Zurich (Switzerland); University Hospital Zurich, Nuclear Cardiology, Cardiovascular Center, Zurich (Switzerland); Kaufmann, Philipp A. [University Hospital Zurich, Cardiac Imaging, Zurich (Switzerland); Alkadhi, Hatem [University Hospital Zurich, Institute of Diagnostic and Interventional Radiology, Zurich (Switzerland)

    2014-05-15

    Hybrid cardiac single photon emission computed tomography (SPECT)/CT imaging allows combined assessment of anatomical and functional aspects of cardiac disease. In coronary artery disease (CAD), hybrid SPECT/CT imaging allows detection of coronary artery stenosis and myocardial perfusion abnormalities. The clinical value of hybrid imaging has been documented in several subsets of patients. In selected groups of patients, hybrid imaging improves the diagnostic accuracy to detect CAD compared to the single imaging techniques. Additionally, this approach facilitates functional interrogation of coronary stenoses and guidance with regard to revascularization procedures. Moreover, the anatomical information obtained from CT coronary angiography or coronary artery calcium scores (CACS) adds prognostic information over perfusion data from SPECT. The use of cardiac hybrid imaging has been favoured by the dissemination of dedicated hybrid systems and the release of dedicated image fusion software, which allow simple patient throughput for hybrid SPECT/CT studies. Further technological improvements such as more efficient detector technology to allow for low-radiation protocols, ultra-fast image acquisition and improved low-noise image reconstruction algorithms will be instrumental to further promote hybrid SPECT/CT in research and clinical practice. (orig.)

  14. Assessing Ecological Flow Needs and Risks for Springs and Baseflow Streams With Growth and Climate Change

    Science.gov (United States)

    Springer, A. E.; Stevens, L. E.

    2008-12-01

    Ecological flow needs assessments are beginning to become an important part of regulated river management, but are more challenging for unregulated rivers. Water needs for ecosystems are greater than just consumptive use by riparian and aquatic vegetation and include the magnitude, frequency, duration and timing of flows and the depth and annual fluctuations of groundwater levels of baseflow supported streams. An ecological flow needs assessment was adapted and applied to an unregulated, baseflow dependent river in the arid to semi-arid Southwestern U.S. A separate process was developed to determine groundwater sources potentially at risk from climate, land management, or groundwater use changes in a large regional groundwater basin in the same semi-arid region. In 2007 and 2008, workshops with ecological, cultural, and physical experts from agencies, universities, tribes, and other organizations were convened. Flow-ecology response functions were developed with either conceptual or actual information for a baseflow dependent river, and scoring systems were developed to assign values to categories of risks to groundwater sources in a large groundwater basin. A reduction of baseflow to the river was predicted to lead to a decline in cottonwood and willow tree abundance, decreases in riparian forest diversity, and increases in non-native tree species, such as tamarisk. These types of forest vegetation changes would likely cause reductions or loss of some bird species. Loss of riffle habitat through declines in groundwater discharge and the associated river levels would likely lead to declines in native fish and amphibian species. A research agenda was developed to develop techniques to monitor, assess and hopefully better manage the aquifers supporting the baseflow dependent river to prevent potential threshold responses of the ecosystems. The scoring system for categories of risk was applied to four systems (aquifers, springs, standing water bodies, and streams) in

  15. Susceptibility assessment of debris flows using the analytic hierarchy process method-A case study in Subao river valley, China

    Institute of Scientific and Technical Information of China (English)

    Xingzhang Chen; Hui Chen; Yong You; Jinfeng Liu

    2015-01-01

    Many debris flows have occurred in the areas surrounding the epicenter of the Wenchuan earthquake. Susceptibility assessment of debris flows in this area is especially important for disaster prevention and mitigation. This paper studies one of the worst hit areas, the Subao river valley, and the susceptibility assessment of debris flows is performed based on field surveys and remote sensing interpretation. By investigating the formation conditions of debris flows in the valley, the following assessment factors are selected: mixture density of landslides and rock avalanches, distance to the seismogenic fault, stratum lithology, ground roughness, and hillside angle. The weights of the assessment factors are determined by the analytic hierarchy process (AHP) method. Each of the assessment factors is further divided into five grades. Then, the assessment model is built using the multifactor superposition method to assess the debris flow susceptibility. Based on the assessment results, the Subao river valley is divided into three areas: high susceptibility areas, medium susceptibility areas, and low susceptibility areas. The high susceptibility areas are concentrated in the middle of the valley, accounting for 17.6%of the valley area. The medium susceptibility areas are in the middle and lower reaches, most of which are located on both sides of the high susceptibility areas and account for 45.3% of the valley area. The remainders are clas-sified as low susceptibility areas. The results of the model are in accordance with the actual debris flow events that occurred after the earthquake in the valley, confirming that the proposed model is capable of assessing the debris flow susceptibility. The results can also provide guidance for reconstruction planning and debris flow prevention in the Subao river valley.

  16. Functional city zoning. Environmental assessment of eco-geological substance migration flows.

    Science.gov (United States)

    Dubrova, Stanislav V; Podlipskiy, Ivan I; Kurilenko, Vitaliy V; Siabato, Willington

    2015-02-01

    One of the unsolved problems today is that of the division of the natural (geochemical background) and anthropogenic components of substance migration flows, such as complex integrated systems in the supergene zone. Not only qualitative, but also quantitative assessment of each component allows greater understanding of the correlation between the processes within the geological body and their impact on the environment. This study is based on academic knowledge in the field of geological sciences and study group research-developments aimed at the detailed examination of the migration of pollutants in anthropogenically modified city soils and the creation of a methodological framework in the field of the geochemical zoning of substance migration flows in the hypergenesis zone. We demonstrate that certain parameters of "zero-level" pollutant concentration for functional area land use can be developed for each city - the state of the environment before the beginning of a new stage of technogenesis.

  17. Open Thermodynamic System Concept for Fluviokarst Underground Temperature and Discharge Flow Assessments

    Science.gov (United States)

    Machetel, P.; Yuen, D. A.

    2012-12-01

    In this work, we propose to use Open Thermodynamic System (OTS) frameworks to assess temperatures and discharges of underground flows in fluviokarstic systems. The theoretical formulation is built on the first and second laws of thermodynamics. However, such assumptions would require steady states in the Control Volume to cancel the heat exchanges between underground water and embedding rocks. This situation is obviously never perfectly reached in Nature where flow discharges and temperatures vary with rainfalls, recessions and seasonal or diurnal fluctuations. First, we will shortly show that the results of a pumping test campaign on the Cent-Font (Hérault, France) fluviokarst during summer 2005 are consistent with this theoretical approach. Second, we will present the theoretical formalism of the OTS framework that leads to equation systems involving the temperatures and/or the discharges of the underground and surface flows.Third, this approach will be applied to the white (2003) conceptual model of fluviokarst, and we will present the numerical model built to assess the applicability of these assumptions. The first order of the field hydrologic properties observed at the Cent-Fonts resurgence are well described by the calculations based on this OTS framework. If this agreement is necessary, it is not sufficient to validate the method. In order to test its applicability, the mixing process has been modelized as a cooling reaction in a Continuous Stirred Tank Reactor (CSTR) for which matrix and intrusive flows are introduced continuously while effluent water is recovered at the output. The enthalpy of the various flows is conserved except for the part that exchanges heat with the embedding rocks. However the numerical model shows that in the water saturated part of the CS, the matrix flow swepts heat by convective-advective processes while temporal heat fluctuations from intrusive flows cross the CV walls. The numerical model shows that the convective flow from

  18. Cardiovascular complications in acromegaly: methods of assessment.

    Science.gov (United States)

    Vitale, G; Pivonello, R; Galderisi, M; D'Errico, A; Spinelli, L; Lupoli, G; Lombardi, G; Colao, A

    2001-09-01

    Cardiac involvement is common in acromegaly. Evidence for cardiac hypertrophy, dilation and diastolic filling abnormalities has been widely reported in literature. Generally, ventricular hypertrophy is revealed by echocardiography but early data referred increased cardiac size by standard X-ray. Besides, echocardiography investigates cardiac function and value disease. There are new technologic advances in ultrasonic imaging. Pulsed Tissue Doppler is a new non-invasive ultrasound tool which extends Doppler applications beyond the analysis of intra-cardiac flow velocities until the quantitative assessment of the regional myocardial left ventricular wall motion, measuring directly velocities and time intervals of myocardium. The radionuclide techniques permit to study better the cardiac performance. In fact, diastolic as well as systolic function can be assessed at rest and at peak exercise by equilibrium radionuclide angiography. This method has a main advantage of providing direct evaluation of ventricular function, being operator independent. Coronary artery disease has been poorly studied mainly because of the necessity to perform invasive procedures. Only a few cases have been reported with heart failure study by coronarography and having alterations of perfusion which ameliorated after somatostatin analog treatment. More recently, a few data have been presented using perfusional scintigraphy in acromegaly, even if coronary artery disease does not seem very frequent in acromegaly. Doppler analysis of carotid arteries can be also performed to investigate atherosclerosis: however, patients with active acromegaly have endothelial dysfunction more than clear-cut atherosclerotic plaques. In conclusion, careful assessments of cardiac function, morphology and activity need in patients with acromegaly.

  19. Assessment of skin flaps using optically based methods for measuring blood flow and oxygenation.

    Science.gov (United States)

    Payette, Jeri R; Kohlenberg, Elicia; Leonardi, Lorenzo; Pabbies, Arone; Kerr, Paul; Liu, Kan-Zhi; Sowa, Michael G

    2005-02-01

    The objective of this study was to compare two noninvasive techniques, laser Doppler and optical spectroscopy, for monitoring hemodynamic changes in skin flaps. Animal models for assessing these changes in microvascular free flaps and pedicle flaps were investigated. A 2 x 3-cm free flap model based on the epigastric vein-artery pair and a reversed MacFarlane 3 x 10-cm pedicle flap model were used in this study. Animals were divided into four groups, with groups 1 (n = 6) and 2 (n = 4) undergoing epigastric free flap surgery and groups 3 (n = 3) and 4 (n = 10) undergoing pedicle flap surgery. Groups 1 and 4 served as controls for each of the flap models. Groups 2 and 3 served as ischemia-reperfusion models. Optical spectroscopy provides a measure of hemoglobin oxygen saturation and blood volume, and the laser Doppler method measures blood flow. Optical spectroscopy proved to be consistently more reliable in detecting problems with arterial in flow compared with laser Doppler assessments. When spectroscopy was used in an imaging configuration, oxygen saturation images of the entire flap were generated, thus creating a visual picture of global flap health. In both single-point and imaging modes the technique was sensitive to vessel manipulation, with the immediate post operative images providing an accurate prediction of eventual outcome. This series of skin flap studies suggests a potential role for optical spectroscopy and spectroscopic imaging in the clinical assessment of skin flaps.

  20. Fourier Analysis of Peripheral Blood Pressure and Flow in Intraoperative Assessment of Infrainguinal Arterial Reconstructions

    Directory of Open Access Journals (Sweden)

    Cheshmedzhiev Mihail V.

    2014-08-01

    Full Text Available AIM: To assess infrainguinal arterial reconstructions by intraoperative flowmetry under the distal anastomosis using a fast Fourier transformation; calculate and compare the amplitude ratios of peripheral arterial blood pressure and volume flow before and after drug-induced vasodilation of occluded bypass grafts and bypass grafts that have been patent at least for 1 year. To find what magnitude of the change of these ratios indicate a long-term patency of the bypass grafting. PATIENTS AND METHODS: We compared the results of the intraoperative flowmetry tests of 97 patients with infrainguinal arterial reconstructions. The patients were divided into two groups based on the graft status: the grafts in 49 patients were patent for at least a year, and 48 patients had failed bypass. We used a fast Fourier transform (FFT of the pressure and blood flow waves and compared the ratios of their amplitudes before and after administration of a vasodilator drug into the graft. Comparing the ratios obtained before and those after administration of the drug we quantified their change in each group and analysed them. RESULTS: After a drug-induced vasodilation, the blood pressure and flow amplitude ratios for the group with compromised reconstructions were less than 1.9 times smaller than those before drug infusion, while for the group with bypass grafts that had been functional for at least 12 months the ratios declined by more than 1.9≈2 times. CONCLUSION: The magnitude of the change of amplitude ratios of the peripheral pressure and volume flow after drug-induced vasodilation can be used to make an assessment of the bypass graft and the distal arterial segment.

  1. The effect of reforestation on stream flow in Upper Nan river basin using Soil and Water Assessment Tool (SWAT model

    Directory of Open Access Journals (Sweden)

    Winai Wangpimool

    2013-09-01

    The simulation was performed using three reforestation scenarios to assess stream flow:(1 improved disturbed forest, (2 field crops and range grass, and (3 both disturbed forest and field crops. The results of reforestation from scenarios 1 and 3 can increase stream flow in the drought season and can also reduce the flow in the wet season in the main stream and its tributaries. For scenario 2 Reforestation had no significant effect on the main stream.

  2. Assessment of blood coagulation under various flow conditions with ultrasound backscattering.

    Science.gov (United States)

    Huang, Chih-Chung; Wang, Shyh-Hau

    2007-12-01

    Several in vitro studies have employed ultrasonic techniques to detect varying properties of coagulating blood under static or stirred conditions. Most of those studies mainly addressed on the development and feasibility of modalities and however were not fully considering the effect of blood flow. To better elucidate this issue, ultrasonic backscattering were measured from the coagulating porcine blood circulated in a mock flow loop with various steady laminar flows at mean shear rates from 10 to 100 s(-1). A 3 ml of 0.5 M CaCl2 solution for inducing blood coagulation was added to that of 30 ml blood circulated in the conduit. For each measurement carried out with a 10-MHz transducer, backscattered signals digitized at 100-MHz sampling frequency were acquired for a total of 20 min at temporal resolution of 50 A-lines per s. The integrated backscatter (IB) was calculated for assessing backscattering properties of coagulating blood. The results show that blood coagulation tended to be increased corresponding to the addition of CaCl2 solution: the IB was increased approximately 6.1 +/- 0.6 (mean +/- standard deviation), 5.4 +/- 0.9, and 4.5 +/- 1.2 dB at 310 +/- 62, 420 +/- 88, and 610 +/- 102 s associated with mean shear rates of 10, 40, and 100 s(-1), respectively. The rate of increasing IB for evaluating the growth of clot was estimated to be 0.075 +/- 0.017, 0.052 +/- 0.027, and 0.038 +/- 0.012 delta dB delta s(-1) corresponding to the increase of mean shear rates. These results consistently demonstrate that higher shear rate tends to prolong the duration for the flowing blood to be coagulated and to decrease the rate of IB. Moreover, the laminar flow was changed to turbulent flow during that the blood was clotting discerned by spatial variations of ultrasound backscattering in the conduit. All these results validate that ultrasound backscattering is feasible to be utilized for detecting and assessing blood coagulation under dynamic conditions.

  3. Assessment of dedicated low-dose cardiac micro-CT reconstruction algorithms using the left ventricular volume of small rodents as a performance measure

    Energy Technology Data Exchange (ETDEWEB)

    Maier, Joscha, E-mail: joscha.maier@dkfz.de [Medical Physics in Radiology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg (Germany); Sawall, Stefan; Kachelrieß, Marc [Medical Physics in Radiology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany and Institute of Medical Physics, University of Erlangen–Nürnberg, 91052 Erlangen (Germany)

    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

  4. Flow cytometric viability assessment of lactic acid bacteria starter cultures produced by fluidized bed drying.

    Science.gov (United States)

    Bensch, Gerald; Rüger, Marc; Wassermann, Magdalena; Weinholz, Susann; Reichl, Udo; Cordes, Christiana

    2014-06-01

    For starter culture production, fluidized bed drying is an efficient and cost-effective alternative to the most frequently used freeze drying method. However, fluidized bed drying also poses damaging or lethal stress to bacteria. Therefore, investigation of impact of process variables and conditions on viability of starter cultures produced by fluidized bed drying is of major interest. Viability of bacteria is most frequently assessed by plate counting. While reproductive growth of cells can be characterized by the number of colony-forming units, it cannot provide the number of viable-but-nonculturable cells. However, in starter cultures, these cells still contribute to the fermentation during food production. In this study, flow cytometry was applied to assess viability of Lactobacillus plantarum starter cultures by membrane integrity analysis using SYBR®Green I and propidium iodide staining. The enumeration method established allowed for rapid, precise and sensitive determination of viable cell concentration, and was used to investigate effects of fluidized bed drying and storage on viability of L. plantarum. Drying caused substantial membrane damage on cells, most likely due to dehydration and oxidative stress. Nevertheless, high bacterial survival rates were obtained, and granulates contained in the average 2.7 × 10(9) viable cells/g. Furthermore, increased temperatures reduced viability of bacteria during storage. Differences in results of flow cytometry and plate counting suggested an occurrence of viable-but-nonculturable cells during storage. Overall, flow cytometric viability assessment is highly feasible for rapid routine in-process control in production of L. plantarum starter cultures, produced by fluidized bed drying.

  5. Improved flow cytometric assessment reveals distinct microvesicle (cell-derived microparticle signatures in joint diseases.

    Directory of Open Access Journals (Sweden)

    Bence György

    Full Text Available INTRODUCTION: Microvesicles (MVs, earlier referred to as microparticles, represent a major type of extracellular vesicles currently considered as novel biomarkers in various clinical settings such as autoimmune disorders. However, the analysis of MVs in body fluids has not been fully standardized yet, and there are numerous pitfalls that hinder the correct assessment of these structures. METHODS: In this study, we analyzed synovial fluid (SF samples of patients with osteoarthritis (OA, rheumatoid arthritis (RA and juvenile idiopathic arthritis (JIA. To assess factors that may confound MV detection in joint diseases, we used electron microscopy (EM, Nanoparticle Tracking Analysis (NTA and mass spectrometry (MS. For flow cytometry, a method commonly used for phenotyping and enumeration of MVs, we combined recent advances in the field, and used a novel approach of differential detergent lysis for the exclusion of MV-mimicking non-vesicular signals. RESULTS: EM and NTA showed that substantial amounts of particles other than MVs were present in SF samples. Beyond known MV-associated proteins, MS analysis also revealed abundant plasma- and immune complex-related proteins in MV preparations. Applying improved flow cytometric analysis, we demonstrate for the first time that CD3(+ and CD8(+ T-cell derived SF MVs are highly elevated in patients with RA compared to OA patients (p=0.027 and p=0.009, respectively, after Bonferroni corrections. In JIA, we identified reduced numbers of B cell-derived MVs (p=0.009, after Bonferroni correction. CONCLUSIONS: Our results suggest that improved flow cytometric assessment of MVs facilitates the detection of previously unrecognized disease-associated vesicular signatures.

  6. Cardiac catheterization

    Science.gov (United States)

    ... doctor can: Collect blood samples from the heart Measure pressure and blood flow in the heart's chambers and in the large arteries around the heart Measure the oxygen in different parts of your heart ...

  7. A combination of thermal methods to assess coronary pressure and flow dynamics with a pressure-sensing guide wire.

    Science.gov (United States)

    van der Horst, Arjen; Van't Veer, Marcel; van der Sligte, Robin A M; Rutten, Marcel C M; Pijls, Nico H J; van de Vosse, Frans N

    2013-03-01

    Measurement of coronary pressure and absolute flow dynamics have shown great potential in discerning different types of coronary circulatory disease. In the present study, the feasibility of assessing pressure and flow dynamics with a combination of two thermal methods, developed in combination with a pressure-sensor-tipped guide wire, was evaluated in an in vitro coronary model. A continuous infusion thermodilution method was employed to determine the average flow, whereas a thermal anemometric method was utilized to assess the pressure and flow dynamics, simultaneously. In the latter method, the electrical power supplied to an element, kept at constant temperature above ambient temperature, was used as a measure for the shear rate. It was found that, using a single calibration function, the method was able to assess coronary pressure and flow dynamics for different flow amplitudes, heart rates, and different pressure wires. However, due to the fact that the thermal anemometric method cannot detect local shear rate reversal, the method was unable to reliably measure flow dynamics close to zero. Nevertheless, the combined methodology was able to reliably assess diastolic hemodynamics. The diastolic peak flow and average diastolic resistance could be determined with a small relative error of (8 ± 7)% and (7 ± 5)%, respectively.

  8. A three-pillar approach to assessing climate impacts on low flows

    Science.gov (United States)

    Laaha, Gregor; Parajka, Juraj; Viglione, Alberto; Koffler, Daniel; Haslinger, Klaus; Schöner, Wolfgang; Zehetgruber, Judith; Blöschl, Günter

    2016-09-01

    The objective of this paper is to present a framework for assessing climate impacts on future low flows that combines different sources of information, termed pillars. To illustrate the framework three pillars are chosen: (a) extrapolation of observed low-flow trends into the future, (b) rainfall-runoff projections based on climate scenarios and (c) extrapolation of changing stochastic rainfall characteristics into the future combined with rainfall-runoff modelling. Alternative pillars could be included in the overall framework. The three pillars are combined by expert judgement based on a synoptic view of data, model outputs and process reasoning. The consistency/inconsistency between the pillars is considered an indicator of the certainty/uncertainty of the projections. The viability of the framework is illustrated for four example catchments from Austria that represent typical climate conditions in central Europe. In the Alpine region where winter low flows dominate, trend projections and climate scenarios yield consistently increasing low flows, although of different magnitudes. In the region north of the Alps, consistently small changes are projected by all methods. In the regions in the south and south-east, more pronounced and mostly decreasing trends are projected but there is disagreement in the magnitudes of the projected changes. The process reasons for the consistencies/inconsistencies are discussed. For an Alpine region such as Austria the key to understanding low flows is whether they are controlled by freezing and snowmelt processes, or by the summer moisture deficit associated with evaporation. It is argued that the three-pillar approach offers a systematic framework of combining different sources of information aimed at more robust projections than that obtained from each pillar alone.

  9. An Assessment of Wind Plant Complex Flows Using Advanced Doppler Radar Measurements

    Science.gov (United States)

    Gunter, W. S.; Schroeder, J.; Hirth, B.; Duncan, J.; Guynes, J.

    2015-12-01

    As installed wind energy capacity continues to steadily increase, the need for comprehensive measurements of wind plant complex flows to further reduce the cost of wind energy has been well advertised by the industry as a whole. Such measurements serve diverse perspectives including resource assessment, turbine inflow and power curve validation, wake and wind plant layout model verification, operations and maintenance, and the development of future advanced wind plant control schemes. While various measurement devices have been matured for wind energy applications (e.g. meteorological towers, LIDAR, SODAR), this presentation will focus on the use of advanced Doppler radar systems to observe the complex wind flows within and surrounding wind plants. Advanced Doppler radars can provide the combined advantage of a large analysis footprint (tens of square kilometers) with rapid data analysis updates (a few seconds to one minute) using both single- and dual-Doppler data collection methods. This presentation demonstrates the utility of measurements collected by the Texas Tech University Ka-band (TTUKa) radars to identify complex wind flows occurring within and nearby operational wind plants, and provide reliable forecasts of wind speeds and directions at given locations (i.e. turbine or instrumented tower sites) 45+ seconds in advance. Radar-derived wind maps reveal commonly observed features such as turbine wakes and turbine-to-turbine interaction, high momentum wind speed channels between turbine wakes, turbine array edge effects, transient boundary layer flow structures (such as wind streaks, frontal boundaries, etc.), and the impact of local terrain. Operational turbine or instrumented tower data are merged with the radar analysis to link the observed complex flow features to turbine and wind plant performance.

  10. Debris Flow Vulnerability Assessment in Urban Area Associated with Landslide Hazard Map : Application to Busan, Korea

    Science.gov (United States)

    Okjeong, Lee; Yoonkyung, Park; Mookwang, Sung; Sangdan, Kim

    2016-04-01

    In this presentation, an urban debris flow disaster vulnerability assessment methodology is suggested with major focus on urban social and economic aspect. The proposed methodology is developed based on the landslide hazard maps that Korean Forest Service has utilized to identify landslide source areas. Frist, debris flows are propagated to urban areas from such source areas by Flow-R model, and then urban vulnerability is evaluated by two categories; physical and socio-economic aspect. The physical vulnerability is associated to buildings that can be broken down by a landslide event directly. This study considers two popular building structure types, reinforced concrete frame and non-reinforced concretes frame, to evaluate the physically-based vulnerability. The socio-economic vulnerability is measured as a function of the resistant levels of the exposed people, the intensity and magnitude of indirect or intangible losses, and preparedness level of the local government. An indicator-based model is established to evaluate the life and indirect loss under urban debris flow disasters as well as the resilience ability against disasters. To illuminate the validity of the suggested methodology, physical and socio-economic vulnerability levels are investigated for Daejeon, Korea using the proposed approach. The results reveal that the higher population density areas under a weaker fiscal condition that are located at the downstream of mountainous areas are more vulnerable than the areas in opposite conditions. Key words: Debris flow disasters, Physical vulnerability, Socio-economic Vulnerability, Urban Acknowledgement This research was supported by a grant(13SCIPS04) from Smart Civil Infrastructure Research Program funded by Ministry of Land, Infrastructure and Transport(MOLIT) of Korea government and Korea Agency for Infrastructure Technology Advancement(KAIA).

  11. Changes in cerebrospinal fluid flow assessed using intraoperative MRI during posterior fossa decompression for Chiari malformation.

    Science.gov (United States)

    Bond, Aaron E; Jane, John A; Liu, Kenneth C; Oldfield, Edward H

    2015-05-01

    OBJECT The authors completed a prospective, institutional review board-approved study using intraoperative MRI (iMRI) in patients undergoing posterior fossa decompression (PFD) for Chiari I malformation. The purpose of the study was to examine the utility of iMRI in determining when an adequate decompression had been performed. METHODS Patients with symptomatic Chiari I malformations with imaging findings of obstruction of the CSF space at the foramen magnum, with or without syringomyelia, were considered candidates for surgery. All patients underwent complete T1, T2, and cine MRI studies in the supine position preoperatively as a baseline. After the patient was placed prone with the neck flexed in position for surgery, iMRI was performed. The patient then underwent a bone decompression of the foramen magnum and arch of C-1, and the MRI was repeated. If obstruction was still present, then in a stepwise fashion the patient underwent dural splitting, duraplasty, and coagulation of the tonsils, with an iMRI study performed after each step guiding the decision to proceed further. RESULTS Eighteen patients underwent PFD for Chiari I malformations between November 2011 and February 2013; 15 prone preincision iMRIs were performed. Fourteen of these patients (93%) demonstrated significant improvement of CSF flow through the foramen magnum dorsal to the tonsils with positioning only. This improvement was so notable that changes in CSF flow as a result of the bone decompression were difficult to discern. CONCLUSIONS The authors observed significant CSF flow changes when simply positioning the patient for surgery. These results put into question intraoperative flow assessments that suggest adequate decompression by PFD, whether by iMRI or intraoperative ultrasound. The use of intraoperative imaging during PFD for Chiari I malformation, whether by ultrasound or iMRI, is limited by CSF flow dynamics across the foramen magnum that change significantly when the patient is

  12. Altered phase interactions between spontaneous blood pressure and flow fluctuations in type 2 diabetes mellitus: Nonlinear assessment of cerebral autoregulation

    Science.gov (United States)

    Hu, Kun; Peng, C. K.; Huang, Norden E.; Wu, Zhaohua; Lipsitz, Lewis A.; Cavallerano, Jerry; Novak, Vera

    2008-04-01

    Cerebral autoregulation is an important mechanism that involves dilatation and constriction in arterioles to maintain relatively stable cerebral blood flow in response to changes of systemic blood pressure. Traditional assessments of autoregulation focus on the changes of cerebral blood flow velocity in response to large blood pressure fluctuations induced by interventions. This approach is not feasible for patients with impaired autoregulation or cardiovascular regulation. Here we propose a newly developed technique-the multimodal pressure-flow (MMPF) analysis, which assesses autoregulation by quantifying nonlinear phase interactions between spontaneous oscillations in blood pressure and flow velocity during resting conditions. We show that cerebral autoregulation in healthy subjects can be characterized by specific phase shifts between spontaneous blood pressure and flow velocity oscillations, and the phase shifts are significantly reduced in diabetic subjects. Smaller phase shifts between oscillations in the two variables indicate more passive dependence of blood flow velocity on blood pressure, thus suggesting impaired cerebral autoregulation. Moreover, the reduction of the phase shifts in diabetes is observed not only in previously-recognized effective region of cerebral autoregulation (type 2 diabetes mellitus alters cerebral blood flow regulation over a wide frequency range and that this alteration can be reliably assessed from spontaneous oscillations in blood pressure and blood flow velocity during resting conditions. We also show that the MMPF method has better performance than traditional approaches based on Fourier transform, and is more suitable for the quantification of nonlinear phase interactions between nonstationary biological signals such as blood pressure and blood flow.

  13. Optoacoustic measurement of central venous oxygenation for assessment of circulatory shock: clinical study in cardiac surgery patients

    Science.gov (United States)

    Petrov, Irene Y.; Prough, Donald S.; Kinsky, Michael; Petrov, Yuriy; Petrov, Andrey; Henkel, S. Nan; Seeton, Roger; Salter, Michael G.; Esenaliev, Rinat O.

    2014-03-01

    Circulatory shock is a dangerous medical condition, in which blood flow cannot provide the necessary amount of oxygen to organs and tissues. Currently, its diagnosis and therapy decisions are based on hemodynamic parameters (heart rate, blood pressure, blood gases) and mental status of a patient, which all have low specificity. Measurement of mixed or central venous blood oxygenation via catheters is more reliable, but highly invasive and associated with complications. Our previous studies in healthy volunteers demonstrated that optoacoustic systems provide non-invasive measurement of blood oxygenation in specific vessels, including central veins. Here we report our first results of a clinical study in coronary artery bypass graft (CABG) surgery patients. We used a medical-grade OPO-based optoacoustic system developed in our laboratory to measure in real time blood oxygenation in the internal jugular vein (IJV) of these patients. A clinical ultrasound imaging system (GE Vivid e) was used for IJV localization. Catheters were placed in the IJV as part of routine care and blood samples taken via the catheters were processed with a CO-oximeter. The optoacoustic oxygenation data were compared to the CO-oximeter readings. Good correlation between the noninvasive and invasive measurements was obtained. The results of these studies suggest that the optoacoustic system can provide accurate, noninvasive measurements of central venous oxygenation that can be used for patients with circulatory shock.

  14. A high-resolution assessment on global nitrogen flows in cropland

    OpenAIRE

    Liu, Junguo; You, Liangzhi; Amini, Manouchehr; Obersteiner, Michael; Herrero, Mario; Zehnder, Alexander J. B.; Yang, Hong

    2010-01-01

    Crop production is the single largest cause of human alteration of the global nitrogen cycle. We present a comprehensive assessment of global nitrogen flows in cropland for the year 2000 with a spatial resolution of 5 arc-minutes. We calculated a total nitrogen input (IN) of 136.60 trillion grams (Tg) of N per year, of which almost half is contributed by mineral nitrogen fertilizers, and a total nitrogen output (OUT) of 148.14 Tg of N per year, of which 55% is uptake by harvested crops and cr...

  15. A high-resolution assessment on global nitrogen flows in cropland

    OpenAIRE

    Liu, J.; L. YOU; M. Amini; OBERSTEINER M.; Herrero, M.; Zehnder, A. J. B.; H. Yang

    2010-01-01

    Crop production is the single largest cause of human alteration of the global nitrogen cycle. We present a comprehensive assessment of global nitrogen flows in cropland for the year 2000 with a spatial resolution of 5 arc-minutes. We calculated a total nitrogen input (IN) of 136.60 trillion grams (Tg) of N per year, of which almost half is contributed by mineral nitrogen fertilizers, and a total nitrogen output (OUT) of 148.14 Tg of N per year, of which 55% is uptake by harvested crops and...

  16. Cardiac MRI in Athletes

    NARCIS (Netherlands)

    Luijkx, T.

    2012-01-01

    Cardiac magnetic resonance imaging (CMR) is often used in athletes to image cardiac anatomy and function and is increasingly requested in the context of screening for pathology that can cause sudden cardiac death (SCD). In this thesis, patterns of cardiac adaptation to sports are investigated with C

  17. The ADOPT trial (Assessment of Efficacies of Cardiac Resynchronization Therapies (CRT-P/D for Heart Failure Patients in China: rationale, design, and end-points

    Directory of Open Access Journals (Sweden)

    Liu B

    2011-06-01

    Full Text Available Bing Liu1*, Fu Yi1*, Hongwei Cai2, Wenyi Guo1, Weijie Li1, Min Shen1, Jielai Xia3, Liwen Liu4, Haichang Wang1, on behalf of The ADOPT Study Steering Committee and Investigators1Department of Cardiology, Xijing Hospital, FMMU, Xi’an, China; 2Department of Information, School of Stomatology, FMMU, Xi’an, China; 3Department of Statistics, FMMU, Xi’an, China; 4Department of Ultrasound, Xijing Hospital, FMMU, Xi’an, ChinaClinicalTrials.gov number, NCT01018667*Both authors contributed equally to this workBackground: Cardiac resynchronization therapy (CRT is a novel nonpharmacological treatment for patients with chronic heart failure (CHF. Some clinical trials conducted in Western countries have demonstrated that CRT could improve CHF patients’ symptoms and reduce mortality. However, due to the differences in economic and social conditions as well as inconsistencies in CHF etiologies between China and Western countries, there is an urgent need to conduct a large-scale CRT clinical study in Chinese patients with CHF. The ADOPT Trial (Assessment of Efficacies of Cardiac Resynchronization Therapies (CRT-P/D for Heart Failure Patients in China is designed to observe whether CRT can further improve syptoms and reduce mortality in Chinese patients in addition to optimal pharmalogical therapy.Methods: The ADOPT study is a prospective, nested, case-controlled, open-label clinical trial. About 40 centers across China participate in this study with a planned 800 Chinese cases to be enrolled. All patients will receive optimal medical treatment. Patients who have successful CRT-P/D implant will be assigned to the CRT group. According to the baseline evaluation, matched cases will be selected from the enrolled optimal pharmaceutical therapy alone group (Group for Selection. After successful match, the cases in Group for Selection enter into follow-up and become the control group. The unmatched cases in the Group for Selection will be removed. If patients

  18. Sensitive cardiac troponins and N-terminal pro-B-type natriuretic peptide in stable coronary artery disease: correlation with left ventricular function as assessed by myocardial strain.

    Science.gov (United States)

    Smedsrud, Marit Kristine; Gravning, Jørgen; Omland, Torbjørn; Eek, Christian; Mørkrid, Lars; Skulstad, Helge; Aaberge, Lars; Bendz, Bjørn; Kjekshus, John; Edvardsen, Thor

    2015-06-01

    N-terminal pro-B-type natriuretic peptide (NT-proBNP) and cardiac troponins (cTns) measured with sensitive assays provide strong prognostic information in patients with stable coronary artery disease. However, the relationship between these biomarkers and myocardial contractile function, as well as infarct size, in this patient group, remains to be defined. The study population consisted of 160 patients referred to a follow-up echocardiography scheduled 1 year after coronary revascularization. Concentrations of NT-proBNP, high-sensitive cTnT (hs-cTnT) and sensitive cTnI assays were assessed. Left ventricular function was measured as global peak systolic longitudinal strain by speckle tracking echocardiography and infarct size was assessed by late-enhancement MRI. NT-proBNP and sensitive cTnI levels were significantly associated with left ventricular function by peak systolic strain (R-values 0.243 and 0.228, p = 0.002 and 0.004) as well as infarct size (R-values 0.343 and 0.366, p = 0.014 and p = 0.008). In contrast, hs-cTnT did not correlate with left ventricular function (R = 0.095, p = 0.231) and only marginally with infarct size (R = 0.237, p = 0.094). NT-proBNP and sensitive cTnI levels correlate with left ventricular function and infarct size in patients with stable coronary artery disease after revascularization. As opposed to hs-cTnT, NT-proBNP and cTnI seem to be indicators of incipient myocardial dysfunction and the extent of myocardial necrosis.

  19. Can exercise capacity assessed by the 6 minute walk test predict the development of major adverse cardiac events in patients with STEMI after fibrinolysis?

    Directory of Open Access Journals (Sweden)

    Ayman K M Hassan

    Full Text Available 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 III450 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.

  20. Assessment of intracardiac flow and vorticity in the right heart of patients after repair of tetralogy of Fallot by flow-sensitive 4D MRI

    Energy Technology Data Exchange (ETDEWEB)

    Hirtler, Daniel [University Hospital Freiburg, Department of Congenital Heart Defects and Pediatric Cardiology (Heart Center, University of Freiburg), Freiburg (Germany); Garcia, Julio; Barker, Alex J. [Northwestern University Feinberg School of Medicine, Department of Radiology, Chicago, IL (United States); Geiger, Julia [University Childrens' Hospital Zurich, Department of Radiology, Zurich (Switzerland)

    2016-10-15

    To comprehensively and quantitatively analyse flow and vorticity in the right heart of patients after repair of tetralogy of Fallot (rTOF) compared with healthy volunteers. Time-resolved flow-sensitive 4D MRI was acquired in 24 rTOF patients and 12 volunteers. Qualitative flow evaluation was based on consensus reading of two observers. Quantitative analysis included segmentation of the right atrium (RA) and ventricle (RV) in a four-chamber view to extract volumes and regional haemodynamic information for computation of regional mean and peak vorticity. Right heart intra-atrial, intraventricular and outflow tract flow patterns differed considerably between rTOF patients and volunteers. Peak RA and mean RV vorticity was significantly higher in patients (p = 0.02/0.05). Significant negative correlations were found between patients' maximum and mean RV and RA vorticity and ventricular volumes (p < 0.05). The main pulmonary artery (MPA) regurgitant flow was associated with higher RA and RV vorticity, which was significant for RA maximum and RV mean vorticity (p = 0.01/0.03). The calculation of vorticity based on 4D flow data is an alternative approach to assess intracardiac flow changes in rTOF patients compared with qualitative flow visualization. Alterations in intracardiac vorticity could be relevant with regard to the development of RV dilation and impaired function. (orig.)

  1. Receiver-Operating-Characteristic Analysis Reveals Superiority of Scale-Dependent Wavelet and Spectral Measures for Assessing Cardiac Dysfunction

    CERN Document Server

    Thurner, S; Lowen, S B; Teich, M C; Thurner, Stefan; Feurstein, Markus C.; Lowen, Steven B.; Teich, Malvin C.

    1998-01-01

    Receiver-operating-characteristic (ROC) analysis was used to assess the suitability of various heart rate variability (HRV) measures for correctly classifying electrocardiogram records of varying lengths as normal or revealing the presence of heart failure. Scale-dependent HRV measures were found to be substantially superior to scale-independent measures (scaling exponents) for discriminating the two classes of data over a broad range of record lengths. The wavelet-coefficient standard deviation at a scale near 32 heartbeat intervals, and its spectral counterpart near 1/32 cycles per interval, provide reliable results using record lengths just minutes long. A jittered integrate-and-fire model built around a fractal Gaussian-noise kernel provides a realistic, though not perfect, simulation of heartbeat sequences.

  2. Physiologic assessment of coronary artery disease: Focus on fractional flow reserve

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Do Yeon; Koo, Bon Kwon [Dept. of Radiology, Internal Medicine and Cardiovascular Center, Seoul National University Hospital, Seoul (Korea, Republic of); Lee, Joo Myung [Dept. of Internal Medicine and Cardiovascular Center, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

    2016-06-15

    The presence of myocardial ischemia is the most important prognostic factor in patients with ischemic heart disease. Fractional flow reserve (FFR) is a gold standard invasive method used to detect the stenosis-specific myocardial ischemia. FFR-guided revascularization strategy is superior to angiography-guided strategy. The recently developed hyperemia-free index, instantaneous wave free ratio is being actively investigated. A non-invasive FFR derived from coronary CT angiography is now used in clinical practice. Due to rapid expansion of invasive and non-invasive physiologic assessment, comprehensive understanding of the role and potential pitfalls of each modality are required for its application. In this review, we focus on the basic and clinical aspects of physiologic assessment in ischemic heart disease.

  3. Mobile phone based laser speckle contrast imager for assessment of skin blood flow

    Science.gov (United States)

    Jakovels, Dainis; Saknite, Inga; Krievina, Gita; Zaharans, Janis; Spigulis, Janis

    2014-10-01

    Assessment of skin blood flow is of interest for evaluation of skin viability as well as for reflection of the overall condition of the circulatory system. Laser Doppler perfusion imaging (LDPI) and laser speckle contrast imaging (LASCI) are optical techniques used for assessment of skin perfusion. However, these systems are still too expensive and bulky to be widely available. Implementation of such techniques as connection kits for mobile phones have a potential for primary diagnostics. In this work we demonstrate simple and low cost LASCI connection kit for mobile phone and its comparison to laser Doppler perfusion imager. Post-occlusive hyperemia and local thermal hyperemia tests are used to compare both techniques and to demonstrate the potential of LASCI device.

  4. Physiologic Assessment of Coronary Artery Disease: Focus on Fractional Flow Reserve.

    Science.gov (United States)

    Hwang, Doyeon; Lee, Joo Myung; Koo, Bon-Kwon

    2016-01-01

    The presence of myocardial ischemia is the most important prognostic factor in patients with ischemic heart disease. Fractional flow reserve (FFR) is a gold standard invasive method used to detect the stenosis-specific myocardial ischemia. FFR-guided revascularization strategy is superior to angiography-guided strategy. The recently developed hyperemia-free index, instantaneous wave free ratio is being actively investigated. A non-invasive FFR derived from coronary CT angiography is now used in clinical practice. Due to rapid expansion of invasive and non-invasive physiologic assessment, comprehensive understanding of the role and potential pitfalls of each modality are required for its application. In this review, we focus on the basic and clinical aspects of physiologic assessment in ischemic heart disease.

  5. Transthoracic Doppler echocardiography – noninvasive diagnostic window for coronary flow reserve assessment

    Directory of Open Access Journals (Sweden)

    Dimitrow Paweł

    2003-04-01

    Full Text Available Abstract This review focuses on transthoracic Doppler echocardiography as noninvasive method used to assess coronary flow reserve (CFR in a wide spectrum of clinical settings. Transthoracic Doppler echocardiography is rapidly gaining appreciation as popular tool to measure CFR both in stenosed and normal epicardial coronary arteries (predominantly in left anterior descending coronary artery. Post-stenotic CFR measurement is helpful in: functional assessment of moderate stenosis, detection of significant or critical stenosis, monitoring of restenosis after revascularization. In the absence of stenosis in the epicardial coronary artery, decreased CFR enable to detect impaired microvascular vasodilatation in: reperfused myocardial infarct, arterial hypertension with or without left ventricular hypertrophy, diabetes mellitus, hypercholesterolemia, syndrome X, hypertrophic cardiomyopathy. In these diseases, noninvasive transthoracic Doppler echocardiography allows for serial CFR evaluations to explore the effect of various pharmacological therapies.

  6. Assessment of cerebral blood flow autoregulation (CBF AR) with rheoencephalography (REG): studies in animals

    Science.gov (United States)

    Popovic, Djordje; Bodo, Michael; Pearce, Frederick; van Albert, Stephen; Garcia, Alison; Settle, Tim; Armonda, Rocco

    2013-04-01

    The ability of cerebral vasculature to regulate cerebral blood flow (CBF) in the face of changes in arterial blood pressure (SAP) or intracranial pressure (ICP) is an important guard against secondary ischemia in acute brain injuries, and official guidelines recommend that therapeutic decisions be guided by continuous monitoring of CBF autoregulation (AR). The common method for CBF AR monitoring, which rests on real-time derivation of the correlation coefficient (PRx) between slow oscillations in SAP and ICP is, however, rarely used in clinical practice because it requires invasive ICP measurements. This study investigated whether the correlation coefficient between SAP and the pulsatile component of the non-invasive transcranial bioimpedance signal (rheoencephalography, REG) could be used to assess the state and lower limit of CBF AR. The results from pigs and rhesus macaques affirm the utility of REG; however, additional animal and clinical studies are warranted to assess selectivity of automatic REG-based evaluation of CBF AR.

  7. Relationship between peak cardiac pumping capability and indices of cardio-respiratory fitness in healthy individuals.

    Science.gov (United States)

    Jakovljevic, Djordje G; Popadic-Gacesa, Jelena Z; Barak, Otto F; Nunan, David; Donovan, Gay; Trenell, Michael I; Grujic, Nikola G; Brodie, David A

    2012-09-01

    Cardiac power output (CPO) is a unique and direct measure of overall cardiac function (i.e. cardiac pumping capability) that integrates both flow- and pressure-generating capacities of the heart. The present study assessed the relationship between peak exercise CPO and selected indices of cardio-respiratory fitness. Thirty-seven healthy adults (23 men and 14 women) performed an incremental exercise test to volitional fatigue using the Bruce protocol with gas exchange and ventilatory measurements. Following a 40-min recovery, the subjects performed a constant maximum workload exercise test at or above 95% of maximal oxygen consumption. Cardiac output was measured using the exponential CO(2) rebreathing method. The CPO, expressed in W, was calculated as the product of the mean arterial blood pressure and cardiac output. At peak exercise, CPO was well correlated with cardiac output (r = 0·92, P<0·01), stroke volume (r = 0·90, P<0·01) and peak oxygen consumption (r = 0·77, P<0·01). The coefficient of correlation was moderate between CPO and anaerobic threshold (r = 0·47, P<0·01), oxygen pulse (r = 0·57, P<0·01), minute ventilation (r = 0·53, P<0·01) and carbon dioxide production (r = 0·56, P<0·01). Small but significant relationship was found between peak CPO and peak heart rate (r = 0·23, P<0·05). These findings suggest that only peak cardiac output and stroke volume truly reflect CPO. Other indices of cardio-respiratory fitness such as oxygen consumption, anaerobic threshold, oxygen pulse, minute ventilation, carbon dioxide production and heart rate should not be used as surrogates for overall cardiac function and pumping capability of the heart.

  8. An assessment of aquifer storage recovery using ground water flow models.

    Science.gov (United States)

    Lowry, Christopher S; Anderson, Mary P

    2006-01-01

    Owing to increased demands on ground water accompanied by increased drawdowns, technologies that use recharge options, such as aquifer storage recovery (ASR), are being used to optimize available water resources and reduce adverse effects of pumping. In this paper, three representative ground water flow models were created to assess the impact of hydrogeologic and operational parameters/factors on recovery efficiency of ASR systems. Flow/particle tracking and solute transport models were used to track the movement of water during injection, storage, and recovery. Results from particle tracking models consistently produced higher recovery efficiency than the solute transport models for the parameters/properties examined because the particle tracking models neglected mixing of the injected and ambient water. Mixing between injected and ambient water affected recovery efficiency. Results from this study demonstrate the interactions between hydrogeologic and operational parameters on predictions of recovery efficiency. These interactions are best simulated using coupled numerical ground water flow and transport models that include the effects of mixing of injected water and ambient ground water.

  9. Best practices for application of attachment cells to in vitro micronucleus assessment by flow cytometry.

    Science.gov (United States)

    Bemis, Jeffrey C; Bryce, Steven M; Nern, Marlies; Raschke, Marian; Sutter, Andreas

    2016-01-01

    This work seeks to provide users with guidance on cell culture, treatment, processing and analytical conditions for achieving optimal performance of the in vitro micronucleus assay using the In Vitro MicroFlow(®) method. Experimental data are provided to support the advice described. The information provided covers specific topics or issues that are identified as critical to the methodology and thus is meant to work with instruction manuals, published papers and other references, and not as a replacement for these documents. The content is divided into several sections. Cell culture and treatment describes conditions for routine maintenance of cells as well as treatment with test articles. Preparation and processing of samples details steps found to be critical in execution of the procedure. Instrument parameters and analysis covers set-up of the flow cytometer and evaluation of the samples. General assay considerations and interpretation of results describes examination of data in terms of assay validity, viability and genotoxicity assessment. The goal is to educate users and enable them to design, conduct and interpret flow cytometric in vitro micronucleus (MN) studies. Readers should obtain an understanding of specific cell culture practices, options for assay formatting and execution and the information required to successfully integrate and validate the in vitro MN assay into their existing safety program.

  10. A novel human artery model to assess the magnetic accumulation of SPIONs under flow conditions

    Science.gov (United States)

    Janikowska, Agata; Matuszak, Jasmin; Lyer, Stefan; Schreiber, Eveline; Unterweger, Harald; Zaloga, Jan; Groll, Jürgen; Alexiou, Christoph; Cicha, Iwona

    2017-01-01

    Magnetic targeting utilises the properties of superparamagnetic iron oxide nanoparticles (SPIONs) to accumulate particles in specified vasculature regions under an external magnetic field. As the behaviour of circulating particles varies depending on nanoparticle characteristics, magnetic field strength and flow dynamics, we established an improved ex vivo model in order to estimate the magnetic capture of SPIONs in physiological-like settings. We describe here a new, easy to handle ex vivo model of human umbilical artery. Using this model, the magnetic targeting of different types of SPIONs under various external magnetic field gradients and flow conditions was investigated by atomic emission spectroscopy and histology. Among tested particles, SPION-1 with lauric acid shell had the largest capacity to accumulate at the specific artery segment. SPION-2 (lauric acid/albumin-coated) were also successfully targeted, although the observed peak in the iron content under the tip of the magnet was smaller than for SPION-1. In contrast, we did not achieve magnetic accumulation of dextran-coated SPION-3. Taken together, the umbilical artery model constitutes a time- and cost-efficient, 3R-compliant tool to assess magnetic targeting of SPIONs under flow. Our results further imply the possibility of an efficient in vivo targeting of certain types of SPIONs to superficial arteries. PMID:28176885

  11. Gene-Specific Assessment of Guanine Oxidation as an Epigenetic Modulator for Cardiac Specification of Mouse Embryonic Stem Cells.

    Directory of Open Access Journals (Sweden)

    Joonghoon Park

    Full Text Available Epigenetics have essential roles in development and human diseases. Compared to the complex histone modifications, epigenetic changes on mammalian DNA are as simple as methylation on cytosine. Guanine, however, can be oxidized as an epigenetic change which can undergo base-pair transversion, causing a genetic difference. Accumulating evidence indicates that reactive oxygen species (ROS are important signaling molecules for embryonic stem cell (ESC differentiation, possibly through transient changes on genomic DNA such as 7,8-dihydro-8-oxoguanine (8-oxoG. Technical limitations on detecting such DNA modifications, however, restrict the investigation of the role of 8-oxoG in ESC differentiation. Here, we developed a Hoogsteen base pairing-mediated PCR-sequencing assay to detect 8-oxoG lesions that can subsequently cause G to T transversions during PCR. We then used this assay to assess the epigenetic and transient 8-oxoG formation in the Tbx5 gene of R1 mouse ESCs subjected to oxidative stress by removing 2-mercaptoethanol (2ME from the culture media. To our surprise, significantly higher numbers of 8-oxoG-mediated G∙C to C∙G transversion, not G∙C to T∙A, were detected at 7th and 9th base position from the transcription start site of exon 1 of Tbx5 in ESCs in the (-2ME than (+2ME group (p < 0.05. This was consistent with the decrease in the amount of amplifiable of DNA harboring the 8-oxoG lesions at the Tbx5 promoter region in the oxidative stressed ESCs. The ESCs responded to oxidative stress, possibly through the epigenetic effects of guanine oxidation with decreased proliferation (p < 0.05 and increased formation of beating embryoid bodies (EBs; p < 0.001. Additionally, the epigenetic changes of guanine induced up-regulation of Ogg1 and PolB, two base excision repairing genes for 8-oxoG, in ESCs treated with (-2ME (p < 0.01. Together, we developed a gene-specific and direct quantification assay for guanine oxidation. Using oxidative

  12. Assessment of turbulence models for pulsatile flow inside a heart pump.

    Science.gov (United States)

    Al-Azawy, Mohammed G; Turan, A; Revell, A

    2016-02-01

    Computational fluid dynamics (CFD) is applied to study the unsteady flow inside a pulsatile pump left ventricular assist device, in order to assess the sensitivity to a range of commonly used turbulence models. Levels of strain and wall shear stress are directly relevant to the evaluation of risk from haemolysis and thrombosis, and thus understanding the sensitivity to these turbulence models is important in the assessment of uncertainty in CFD predictions. The study focuses on a positive displacement or pulsatile pump, and the CFD model includes valves and moving pusher plate. An unstructured dynamic layering method was employed to capture this cyclic motion, and valves were simulated in their fully open position to mimic the natural scenario, with in/outflow triggered at control planes away from the valves. Six turbulence models have been used, comprising three relevant to the low Reynolds number nature of this flow and three more intended to investigate different transport effects. In the first group, we consider the shear stress transport (SST) [Formula: see text] model in both its standard and transition-sensitive forms, and the 'laminar' model in which no turbulence model is used. In the second group, we compare the one equation Spalart-Almaras model, the standard two equation [Formula: see text] and the full Reynolds stress model (RSM). Following evaluation of spatial and temporal resolution requirements, results are compared with available experimental data. The model was operated at a systolic duration of 40% of the pumping cycle and a pumping rate of 86 BPM (beats per minute). Contrary to reasonable preconception, the 'transition' model, calibrated to incorporate additional physical modelling specifically for these flow conditions, was not noticeably superior to the standard form of the model. Indeed, observations of turbulent viscosity ratio reveal that the transition model initiates a premature increase of turbulence in this flow, when compared with

  13. Beyond the Knudsen number: assessing thermodynamic non-equilibrium in gas flows

    CERN Document Server

    Meng, Jianping; Reese, Jason M; Zhang, Yonghao

    2012-01-01

    For more than 150 years the Navier-Stokes equations for thermodynamically quasi-equilibrium flows have been the cornerstone of modern computational fluid dynamics that underpins new fluid technologies. However, the applicable regime of the Navier-Stokes model in terms of the level of thermodynamic non-equilibrium in the local flowfield is not clear especially for hypersonic and low-speed micro/nano flows. Here, we re-visit the Navier-Stokes model in the framework of Boltzmann statistics, and propose a new and more appropriate way of assessing non-equilibrium in the local flowfield, and the corresponding appropriateness of the Navier-Stokes model. Our theoretical analysis and numerical simulations confirm our proposed method. Through molecular dynamics simulations we reveal that the commonly-used Knudsen number, or a parametric combination of Knudsen and Mach numbers, may not be sufficient to accurately assess the departure of flowfields from equilibrium, and the applicability of the Navier-Stokes model.

  14. The assessment of the breath hold and the free breath methods about the blood flow evaluation by using phase contrast MRI

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Seong Ho [Dept. of Radiology, Konkuk Medical center, Seoul (Korea, Republic of)

    2016-06-15

    Measurement of cardiac blood flow using the magnetic resonance imaging has been limited due to breathing and involuntary movements of the heart. The present study attempted to improve the accuracy of cardiac blood flow testing through phase contrast magnetic resonance imaging by presenting the adequate breathing method and imaging variables by comparing the measurement values of cardiac blood flow. Each was evaluated by comparing the breath hold retrospective 1NEX and non breath hold retrospective 1-3NEX in the ascending aorta and descending aorta. As a result, the average blood flow amount/ velocity of the breath hold retrosepctive 1NEX method in the ascending aorta were 96.17±19.12 ml/sec, 17.04±4.12 cm/sec respectively, which demonstrates a statistically significant difference(p<0.05) with the non-breath hold retrospective method 1NEX of 72.31±13.27 ml and 12.32±3.85. On the other hand, the average 2NEX blood flow and mean flow velocity is 101.90±24.09, 16.84±4.32, 3NEX 103.06±25.49, 16.88±4.19 did not show statistically significant differences(p>0.05).The average blood flow amount/ velocity of the breath hold retrospective 1NEX method in the descending aorta were 76.68±19.72 ml/s, and 22.23±4.8, which did not demonstrate a significant difference in comparison to non-breath hold retrospective method 1-3 NEX. Therefore, the non breath hold retrospective method does not significantly differ in terms of cardiac blood flow in comparison with the breath hold retrospective method in accordance with the increase of NEX, so pediatric patients or patients who are not able to breathe well must have the diagnostic value of their cardiac blood flow tests improved.

  15. Establishing the flow cytometric assessment of myeloid cells in kidney ischemia/reperfusion injury.

    Science.gov (United States)

    Williams, Timothy M; Wise, Andrea F; Alikhan, Maliha A; Layton, Daniel S; Ricardo, Sharon D

    2014-03-01

    Polychromatic flow cytometry is a powerful tool for assessing populations of cells in the kidney through times of homeostasis, disease and tissue remodeling. In particular, macrophages have been identified as having central roles in these three settings. However, because of the plasticity of myeloid cells it has been difficult to define a specific immunophenotype for these cells in the kidney. This study developed a gating strategy for identifying and assessing monocyte and macrophage subpopulations, along with neutrophils and epithelial cells in the healthy kidney and following ischemia/reperfusion (IR) injury in mice, using antibodies against CD45, CD11b, CD11c, Ly6C, Ly6G, F4/80, CSF-1R (CD115), MHC class II, mannose receptor (MR or CD206), an alternatively activated macrophage marker, and the epithelial cell adhesion marker (EpCAM or CD326). Backgating analysis and assessment of autofluorescence was used to extend the knowledge of various cell types and the changes that occur in the kidney at various time-points post-IR injury. In addition, the impact of enzymatic digestion of kidneys on cell surface markers and cell viability was assessed. Comparisons of kidney myeloid populations were also made with those in the spleen. These results provide a useful reference for future analyses of therapies aimed at modulating inflammation and enhancing endogenous remodeling following kidney injury.

  16. Contributions and Concerns of Concentrated Flow Erosion and Assessment Technologies in Watershed Systems

    Science.gov (United States)

    Bingner, R. L.; Momm, H. G.; Wells, R. R.; Dabney, S. M.

    2012-04-01

    Concentrated runoff increases erosion and efficiently transfers sediment and associated agrichemicals from upland areas to stream channels. Ephemeral gully erosion on cropland in the U.S. may contribute 40% of the sediment delivered to the edge of the field. Typically, conservation practices developed for sheet and rill erosion are also expected to treat ephemeral gully erosion, but technology and tools do not exist to account for the separate benefits and effects of practices on various sediment sources. Practices specifically developed to treat ephemeral gully erosion need further testing, when used in conjunction with sheet and rill erosion control practices. Without improved research studies, subjective observations will continue to be used to satisfy quality criteria in lieu of scientifically defensible, quantitative methods to estimate the impact of gully erosion. Some of the more important limiting components are the identification of and relationships for: (1) ephemeral gully width; (2) soil resistance to gully erosion including a definition for non-erosive layers; (3) the effect of root mass and above ground vegetation on erosion resistance; (4) ephemeral gully networks; and (5) the effect of subsurface flow on ephemeral gullies. Currently, these components are represented through widely divergent to non-existent algorithms. The U.S. Department of Agriculture's AnnAGNPS pollutant loading model has been developed to determine the effects of conservation management plans and provide sediment tracking from all sources within the watershed, including ephemeral gullies. Enhanced technology is also needed to identify where ephemeral gullies may form in the watershed using remote sensing technology. Developing enhanced technology and research for concentrated flow assessments is critical for developing and testing conservation practices specifically designed for gully erosion control. This study will describe the current state of concentrated flow assessment and

  17. Assessing regional cerebral blood flow in depression using 320-slice computed tomography.

    Directory of Open Access Journals (Sweden)

    Yiming Wang

    Full Text Available While there is evidence that the development and course of major depressive disorder (MDD symptomatology is associated with vascular disease, and that there are changes in energy utilization in the disorder, the extent to which cerebral blood flow is changed in this condition is not clear. This study utilized a novel imaging technique previously used in coronary and stroke patients, 320-slice Computed-Tomography (CT, to assess regional cerebral blood flow (rCBF in those with MDD and examine the pattern of regional cerebral perfusion. Thirty nine participants with depressive symptoms (Hamilton Depression Rating Scale 24 (HAMD24 score > 20, and Self-Rating Depression Scale (SDS score > 53 and 41 healthy volunteers were studied. For all subjects, 3 ml of venous blood was collected to assess hematological parameters. Transcranial Doppler (TCD ultrasound was utilized to measure parameters of cerebral artery rCBFV and analyse the Pulsatility Index (PI. 16 subjects (8 =  MDD; 8 =  healthy also had rCBF measured in different cerebral artery regions using 320-slice CT. Differences among groups were analyzed using ANOVA and Pearson's tests were employed in our statistical analyses. Compared with the control group, whole blood viscosity (including high\\middle\\low shear rateand hematocrit (HCT were significantly increased in the MDD group. PI values in different cerebral artery regions and parameters of rCBFV in the cerebral arteries were decreased in depressive participants, and there was a positive relationship between rCBFV and the corresponding vascular rCBF in both gray and white matter. rCBF of the left gray matter was lower than that of the right in MDD. Major depression is characterized by a wide range of CBF impairments and prominent changes in gray matter blood flow. 320-slice CT appears to be a valid and promising tool for measuring rCBF, and could thus be employed in psychiatric settings for biomarker and treatment response purposes.

  18. Large scale debris-flow hazard assessment: a geotechnical approach and GIS modelling

    Directory of Open Access Journals (Sweden)

    G. Delmonaco

    2003-01-01

    Full Text Available A deterministic distributed model has been developed for large-scale debris-flow hazard analysis in the basin of River Vezza (Tuscany Region – Italy. This area (51.6 km 2 was affected by over 250 landslides. These were classified as debris/earth flow mainly involving the metamorphic geological formations outcropping in the area, triggered by the pluviometric event of 19 June 1996. In the last decades landslide hazard and risk analysis have been favoured by the development of GIS techniques permitting the generalisation, synthesis and modelling of stability conditions on a large scale investigation (>1:10 000. In this work, the main results derived by the application of a geotechnical model coupled with a hydrological model for the assessment of debris flows hazard analysis, are reported. This analysis has been developed starting by the following steps: landslide inventory map derived by aerial photo interpretation, direct field survey, generation of a database and digital maps, elaboration of a DTM and derived themes (i.e. slope angle map, definition of a superficial soil thickness map, geotechnical soil characterisation through implementation of a backanalysis on test slopes, laboratory test analysis, inference of the influence of precipitation, for distinct return times, on ponding time and pore pressure generation, implementation of a slope stability model (infinite slope model and generalisation of the safety factor for estimated rainfall events with different return times. Such an approach has allowed the identification of potential source areas of debris flow triggering. This is used to detected precipitation events with estimated return time of 10, 50, 75 and 100 years. The model shows a dramatic decrease of safety conditions for the simulation when is related to a 75 years return time rainfall event. It corresponds to an estimated cumulated daily intensity of 280–330 mm. This value can be considered the hydrological triggering

  19. Debris-flow susceptibility and hazard assessment at a regional scale from GIS analysis

    Science.gov (United States)

    Bertrand, M.; Liébault, F.; Piégay, H.

    2012-12-01

    Small torrents of the Southern French Alps are prone to extreme events. Depending on the rainfall conditions, the sediment supply from hillslopes, and the gravitational energy, these events can occur under different forms, from floods to debris-flows. Debris-flows are recognized as the most dangerous phenomena and may have dramatic consequences for exposed people and infrastructures. As a first step of hazard assessment, we evaluated the debris-flow susceptibility, i.e. the likelihood that an event occurs in an area under particular physical conditions, not including the temporal dimension. The susceptibility is determined by (i) the morphometric controls of small upland catchments for debris-flows triggering and propagation, and by (ii) sediment supply conditions, i.e. erosion patterns feeding the channels. The morphometric controls are evaluated with indicators calculated from basic topographic variables. The sediment supply is evaluated by considering the cumulated surface of erosion area connected to the hydrographic network. We developed a statistical model to predict the geomorphic responses of the catchments (fluvial vs. debris-flow) and we apply this model within a GIS for regional-scale prediction. The model is based on two morphometric indicators, i.e. fan / channel slope and the Melton ruggedness index, and is based on a wide set of data including the Southern French Alps. We developed a GIS procedure to extract the indicators automatically using a 25m DEM and the hydrographic network as raw data. This model and its application have been validated with historical data. Sediment sources feeding debris-flow prone torrents are identified by first automatically mapping the erosion patches from the infrared orthophotos analysis then identifying the ones connected to the stream network. A classification method has been developed (segmentation into homogeneous objects classified with a neural network algorithm) and validated with expert interpretation on the

  20. Assessment of heat sources on the control of fast flow of Vestfonna Ice Cap, Svalbard

    Directory of Open Access Journals (Sweden)

    M. Schäfer

    2013-10-01

    Full Text Available The dynamic regime of Svalbard's Nordaustlandet ice caps is dominated by fast flowing outlet glaciers, making assessment of their response to climate change challenging. A key element of the challenge lies in the fact that the motion of fast outlet glaciers occurs largely through basal sliding, and is governed by physical processes at the glacier bed, processes that are difficult both to observe and to simulate. Up to now, most of the sliding laws used in ice flow models were based on uniform parameters with a condition on temperature to identify regions of basal sliding. However these models are usually not able to reproduce observed velocities with sufficient accuracy. With the development of inverse methods, it is now common to infer a spatially varying field of sliding parameters from surface ice-velocity observations. These parameter distributions usually reflect a high spatial variability and represent valuable information to understand and test various hypotheses on physical processes involved in sliding. However, in these models, basal sliding is uncoupled from the thermal regime of basal ice and the evolution of the sliding parameters in prognostic simulations remains problematic. Here we explore the role of different heat sources (friction heating, strain heating and latent heat through percolation of melt water on the development of sliding and fast flow through thermomechanical coupling on Nordaustlandet outlet glaciers. We focus on Vestfonna with a special emphasis on Franklinbreen, a fast flowing outlet glacier which has been observed to accelerate between 1995 and 2008 and possibly already prior to 1995. We try to reconcile the impacts of temperature and heat sources on basal friction coefficients inferred from observed surface velocities during these two periods. Our simulations reproduce a temperature profile from borehole measurements, allowing an interpretation of the vertical temperature structure in terms of temporal

  1. Extracorporeal Cardiac Shock Wave Therapy Ameliorates Clinical Symptoms and Improves Regional Myocardial Blood Flow in a Patient with Severe Coronary Artery Disease and Refractory Angina

    Directory of Open Access Journals (Sweden)

    Christian Prinz

    2009-01-01

    Full Text Available Different therapeutic options are being used for chronic coronary artery disease (CAD. We report about a 51-year-old female with CAD and refractory angina pectoris despite maximally tolerated medical therapy and after both percutaneous coronary intervention (PCI and coronary artery bypass grafting (CABG. The patient received cardiac shock wave therapy (CSWT over a period of 6 month. There was no arrhythmia during or after treatment; enzyme levels were normal at all times. PET imaging showed a substantial improvement of myocardial stress perfusion. Since the patient reported that she now was fully capable to deal with her everyday life, further treatment options were postponed. Our case report suggests that ultrasound-guided CSWT is able to improve symptoms and perfusion in ischemic myocardium.

  2. Duchenne型肌营养不良携带者心脏损伤评估方法的研究进展%Progress of Cardiac Damage Assessment in Carriers of Duchenne Muscular Dystrophy (review)

    Institute of Scientific and Technical Information of China (English)

    贾梦芸; 吴士文

    2015-01-01

    Duchenne muscular dystrophy (DMD) is an X-linked recessive neuromuscular disorder, and the carriers of DMD can suffer from cardiac damage without muscle weakness, which can predispose to death. Consequently detecting and preventing cardiac damage in the early stage can improve the carriers' quality of life. The detection of early cardiac abnormalities and the evaluation of cardiac function for carriers mainly rely on the different examination methods, including electrocardiogram, echocardiogram, cardiovascular magnetic reso-nance, radioactive nuclide myocardial perfusion imaging and coronary angiography. Carriers of DMD with cardiac damage are assessed by different examination methods in different ways.%Duchenne型肌营养不良(DMD)是一种X染色体连锁隐性遗传性神经肌肉病。DMD基因携带者可在没有肌无力情况下出现心脏损伤,甚至危及生命。早期发现心肌损害,并提前预防可以改变生活质量,降低死亡率。DMD基因携带者心脏损害的早期检查手段包括心电图、心脏超声、心血管磁共振成像、放射性核素心肌灌注显像及冠状血管造影术等。不同检查手段从不同角度评估DMD基因携带者心脏损伤情况。

  3. Relationship between colour flow Doppler sonographic assessment of corpus luteum activity and progesterone concentrations in mares after embryo transfer

    NARCIS (Netherlands)

    Brogan, P. T.; Henning, H.; Stout, T. A E; de Ruijter-Villani, M.

    2016-01-01

    Colour-flow Doppler sonography has been described as a means of assessing corpus luteum (CL) function rapidly, because area of luteal blood vessels correlates well with circulating progesterone (P4) concentrations [P4] in oestrous cycling mares. The aim of this study was to assess the relationships

  4. The relationship between Elder Risk Assessment (ERA scores and cardiac revascularization: a cohort study in Olmsted County, Minnesota, USA

    Directory of Open Access Journals (Sweden)

    Sharma S

    2013-09-01

    Full Text Available Saurabh Sharma,1 Shruti Datta,1 Shahyar Gharacholou,1,2 Shahzad K Siddique,3 Stephen S Cha,4 Paul Y Takahashi1,5,6 1Department of Internal Medicine, Mayo Clinic, Rochester, MN, USA; 2Division of Cardiovascular Medicine, Mayo Clinic, Rochester, MN, USA; 3Shifa International Hospital, Islamabad, Pakistan; 4Department of Health Sciences Research, Mayo Clinic, Rochester, MN, USA; 5Division of Primary Care Internal Medicine, Mayo Clinic, Rochester, MN, USA; 6Kogod Center of Aging, Mayo Clinic, Rochester, MN, USA Purpose: The aging population is predisposed to cardiovascular disease. Our goal was to determine the relationship between a higher Elder Risk Assessment (ERA score and coronary artery bypass graft (CABG or percutaneous coronary intervention (PCI, in adults over 60 years. Methods: This was a retrospective cohort study in a primary care internal medicine practice. Patients included community-dwelling individuals aged 60 years or older on January 1, 2005. The primary outcome was a combined outcome of CABG and PCI in 2 years. The secondary outcome was mortality 5 years after CABG or PCI. The primary predictor variable was the score on the ERA Index, an instrument that predicts emergency room visits and hospitalization. The outcomes were obtained using administrative data from electronic medical records. The analysis included logistic regression, with odds ratios for the primary outcome and time-to-event analysis for mortality. Results: The records of 12,650 patients were studied. A total of 902 patients (7.1% had either CABG or PCI, with an average age of 74.5 years (±8.3 years. There were 205 patients (23% who experienced CABG or PCI in the highest-score group (top 10% compared with 29 patients (3% in the lowest score group, for an odds ratio of 15.4; 95% confidence interval, 10.1–23.5. There was a greater association of revascularization events by increasing score group. We noted increased mortality by increasing ERA score, in patients

  5. Noninvasive assessment of pulmonary arterial pressure by krypton-81m right cardiac ventriculography in patients with chronic obstructive pulmonary disease

    Energy Technology Data Exchange (ETDEWEB)

    Yamaoka, Shimpachi; Kuriyama, Takanobu; Hirai, Masashi; Nishimura, Kouichi; Kuno, Kenshi; Yonekura, Yoshiharu

    1987-10-01

    In twenty patients with COPD, the following pulmonary function test values were obtained (mean +- SD): FEV/sub 1.0/ = 1070 +- 490 ml;FEV/sub 1.0/ % = 47.7 +- 8.9 %;PaO/sub 2/ = 65.8 +- 8.4 torr;PaCO/sub 2/ = 39.7 +- 4.4 torr. All patients underwent right heart catheterization and pulmonary arterial mean pressures (PAMP) were obtained. The PAMP value was 20.2 +- 4.1 torr (range 12 - 28), RVEF was 52.2 +- 8.4 % (range 31 - 63) and RVRFR was 25.5 +- 4.7 %100 msec (range 18 - 34). The PAMP negatively correlated with the RVEF (r = -0.69, p < 0.001) and RVRFR (r = -0.82, p < 0.001). In ten healthy male subjects, the RVEF was 56.6 +- 5.1 % (range 50 - 64) and RVRFR was 37.7 +- 3.0 %100 msec (range 33 - 42). The lower limit of normal for the RVEF was regarded as 46.4 % and that of the RVRFR as 31.7 %100 msec;these are the values two standard deviations below the means. Nine of the twenty patients has a PAMP value of more than 20 torr (the sine qua non of cor pulmonale). Five of these nine patients had RVEF values less than 46.4 % and all of them had RVRFR values of less than 31.7 %100 msec. On the other hand, all of the remaining eleven patients (PAMP 20 torr or less) had RVEF values within the normal range, but ten of the eleven had RVRFR values of less than 31.7 %100 msec. Therefore, the RVRFR value, which showed excellent correlation with the PAMP, provided a noninvasive assessment of pulmonary arterial pressure with good sensitivity in detecting elevated pressure. The RVEF value supplemented the RVRFR with good specificity for detection of elevation of pressure;that is, it eliminated false positive results. (J.P.N.)

  6. Assessment of a five-color flow cytometric assay for verifying automated white blood cell differentials

    Institute of Scientific and Technical Information of China (English)

    HUANG Chun-mei; YU Lian-hui; PU Cheng-wei; WANG Xin; WANG Geng; SHEN Li-song; WANG Jian-zhong

    2013-01-01

    Background White blood cell (WBC) counts and differentials performed using an automated cell counter typically require manual microscopic review.However,this last step is time consuming and requires experienced personnel.We evaluated the clinical efficiency of using flow cytometry (FCM) employing a six-antibody/five-color reagent for verifying automated WBC differentials.Methods A total of 56 apparently healthy samples were assessed using a five-color flow cytometer to verify the normal reference ranges of WBC differentials.WBC differentials of 622 samples were also determined using both a cell counter and FCM.These results were then confirmed using manual microscopic methods.Results The probabilities for all of the parameters of WBC differentials exceeded the corresponding normal reference ranges by no more than 7.5%.The resulting WBC differentials were well correlated between FCM and the cell counter (r >0.88,P <0.001),except in the case of basophils.Neutrophils,lymphocytes,and eosinophils were well correlated between FCM and standard microscopic cytology assessment (r >0.80,P <0.001).The sensitivities of FCM for identification of immature granulocytes and blast cells (72.03% and 22.22%,respectively) were higher than those of the cell counter method (44.92% and 11.11%,respectively).The specificities of FCM were all above 85%,substantially better than those of the cell counter method.Conclusion These five-color FCM assays could be applied to accurately verify abnormal results of automated assessment of WBC differentials.

  7. SOCIAL PARTICIPATION IN THE ENVIRONMENTAL FLOW ASSESSMENT: THE SÃO FRANCISCO RIVER CASE STUDY

    Directory of Open Access Journals (Sweden)

    Yvonilde Dantas Pinto Medeiros

    2013-03-01

    Full Text Available Traditionally, water resource management has been developed using an essentially technical approach. Currently, public opinion on water resource management is formed as a result of growing environmental concerns and social conflicts arising from poorly planned actions. Environmental problems are complex and have multiple dimensions, including social and economic. Therefore, the inclusion of a human dimension in integrated assessment methodologies is required for the introduction of new elements to the water management planning process. Environmental water allocation (EWA is understood as the quantity, quality and distribution of water required for the maintenance of the functions and processes of aquatic ecosystems on which people depend. Within the various holistic assessment methodologies, the Building Block Methodology (BBM was found to be the most suitable, in the Brazilian context, for maintaining and restoring essential elements of the natural flow regime. This article describes the process of social participation in the environmental flow assessment (EFA for the Sao Francisco River, and compares it with some of the lessons learned from EFA in other parts of the world. The process involved multiple stakeholders who have conflicting interests. BBM was used to guide the field interviews, to incorporate the empirical observations by the local population and to guide the methodological procedures of the multidisciplinary team. The results of the study indicate the effectiveness of this holistic approach in organizing the elements to be evaluated. It also facilitated important contributions to the establishment of a dialogue between the actors to achieve a better understanding of the multiple aspects involved in the decisions associated with the EWA.

  8. Assessment of cardiac exposure in left-tangential breast irradiation; evaluation de l'irradiation cardiaque lors de l'irradiation tangentielle du sein gauche

    Energy Technology Data Exchange (ETDEWEB)

    Vees, H. [Department of Radiation Oncology, University of Bern, Inselspital, Bern (Switzerland); Department of Radiation Oncology, Hopital de Sion, avenue de Grand-Champsec 80, Sion 1951 (Switzerland); Bigler, R.; Gruber, G. [Department of Radiation Oncology, University of Bern, Inselspital, Bern (Switzerland); Bieri, S. [Department of Radiation Oncology, Hopital de Sion, avenue de Grand-Champsec 80, Sion 1951 (Switzerland)

    2011-12-15

    Purpose. - To assess the value of treatment-planning related parameters namely, the breast volume; the distance of the inferior field border to diaphragm; and the cardio-thoracic ratio for left-tangential breast irradiation. Patients and methods. - Treatment plans of 27 consecutively left-sided breast cancer patients after breast conserving surgery were evaluated for several parameters concerning heart-irradiation. We measured the heart distance respective to the cardio-thoracic ratio and the distance of the inferior field border to diaphragm, as well as the breast volume in correlation with the irradiated heart volume. Results. - The mean heart and left breast volumes were 504 cm{sup 3} and 672.8 cm{sup 3}, respectively. The mean heart diameter was 13.4 cm; the mean cardio-thoracic ratio 0.51 and the mean distance of the inferior field border to diaphragm was 1.4 cm. Cardio-thoracic ratio (p = 0.01), breast volume (p = 0.0002), distance of the inferior field border to diaphragm (p = 0.02) and central lung distance (p = 0.02) were significantly correlated with the measured heart distance. A significant correlation was also found between cardio-thoracic ratio, breast volume and distance of the inferior field border to diaphragm with the irradiated heart volume measured by V10, V20 and V40. Conclusion. - The verification of parameters like cardio-thoracic ratio, distance of the inferior field border to diaphragm and breast volume in left-sided breast cancer patients may help in determining which patients could benefit from more complex planning techniques such as intensity-modulated radiotherapy to reduced risk of late cardiac injury. (authors)

  9. Assessment of left ventricular ejection fraction: comparison of two dimensional echocardiography, cardiac magnetic resonance imaging and 64-row multi-detector computed tomography

    Institute of Scientific and Technical Information of China (English)

    Chee Khoon LIEW; Kui Hian SIM; Rapaee ANNUAR; Tiong Kiam ONG; Sze Piaw CHIN; Tobias Seyfarth; Yean Yip FONG; Wei Ling CHAN; Choon Kiat ANG; Houng Bang LIEW

    2006-01-01

    Objectives To compare left ventricular ejection fraction (LVEF) determined from 64-row multi-detector computed tomography (64-row MDCT) with those determined from two dimensional echocardiography (2D echo) and cardiac magnetic resonance imaging (CMR). Methods Thirty-two patients with coronary artery disease underwent trans-thoracic 2D echo, CMR and contrast-enhanced 64-row MDCT for assessment of LVEF within 48 hours of each other. 64-row MDCT LVEF was derived using the Syngo Circulation software; CMR LVEF was by Area Length Ejection Fraction (ALEF) and Simpson method and 2D echo LVEF by Simpson method.Results The LVEF was 49.13 ± 15.91% by 2D echo, 50.72 ± 16.55% (ALEF method) and 47.65 ± 16.58%(Simpson method) by CMR and 50.00 ± 15.93% by 64-row MDCT. LVEF measurements by 64-row MDCT correlated well with LVEF measured with CMR using either the ALEF method (Pearson correlation r = 0.94, P <0.01) or Simpson method (r = 0.92, P<0.01). It also correlated well with LVEF measured using 2D echo (r = 0.80, P < 0.01). Conclusion LVEF measurements by 64-row MDCT correlated well with LVEF measured by CMR and 2D echo. The correlation between 64-row MDCT and CMR was better than the correlation between 2D echo with CMR. Standard data set from a 64-row MDCT coronary study can be reliably used to calculate the LVEF.

  10. Cardiac functions assessment in children with celiac disease and its correlation with the degree of mucosal injury: Doppler tissue imaging study

    Directory of Open Access Journals (Sweden)

    Abeer Fathy

    2016-01-01

    Full Text Available Background/Aims: Celiac disease (CD-associated cardiologic disorders is a growing concern. However, data regarding cardiac affection in children with CD are few. This study aimed at assessing the subclinical impact of CD on the global myocardial performance in Saudi children with CD using Doppler tissue imaging (DTI. Patients and Methods: Conventional two-dimensional echocardiography was performed among 20 Saudi children with CDas well as 20 age and sex-matched healthy controls. DTI were used to determine right ventricular (RV and left ventricular (LV Tei indexes. These findings were correlated with the Modified Marsh Classification of the histologic findings in CD. Results: LV and RV Tei indexes were significantly higher in children with CD than the control group (mean ± standard deviation: 0.47 ± 0.05 vs. 0.31 ± 0.18; P< 0.0005 and 0.51 ± 0.04 vs. 0.32 ± 0.05; P< 0.0001, respectively. RV Tei index was found to be positively correlated with the Modified Marsh Classification of CD (r = 0.7753, P< 0.0001. LV Tei index tended to be more affected in patients with more severe histologic findings, however, such relation did not reach statistical significance (r = 0.2479, P = 0.292. Fractional shortening did not correlate with the Modified Marsh Classification of histologic findings in CD patients (r= −0.11, P = 0.641. Conclusions: Subclinical myocardial dysfunction of both ventricles occurs in children with CD. The DTI method appears to be more sensitive than conventional two-dimensional echocardiography in the early detection of myocardial dysfunction in children with CD.

  11. Non-cardiac QTc-prolonging drugs and the risk of sudden cardiac death

    NARCIS (Netherlands)

    Straus, SMJM; Sturkenboom, MCJM; Bleumink, GS; van der Lei, J; de Graeff, PA; Kingma, JH; Stricker, BHC

    2005-01-01

    Aims To assess the association between the use of non-cardiac QTc-prolonging drugs and the risk of sudden cardiac death. Methods and results A population-based case-control study was performed in the Integrated Primary Care Information (IPCI) project, a longitudinal observational database with compl

  12. 4D flow MRI assessment of extracranial-intracranial bypass: qualitative and quantitative evaluation of the hemodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Sekine, Tetsuro [University Hospital Zurich/University of Zurich, Department of Medical Radiology, Division of Nuclear Medicine, Zurich (Switzerland); Nippon Medical School, Department of Radiology, Tokyo (Japan); Takagi, Ryo; Amano, Yasuo; Orita, Erika; Matsumura, Yoshio; Kumita, Shin-ichiro [Nippon Medical School, Department of Radiology, Tokyo (Japan); Murai, Yasuo [Nippon Medical School, Department of Neurological Surgery, Tokyo (Japan)

    2016-03-15

    Our aim was to assess the feasibility of using time-resolved 3D phase-contrast (4D flow) MRI to characterize extracranial-intracranial (EC-IC) bypass. We enrolled 32 patients who underwent EC-IC bypass (15 men, 17 women; mean age 66.4 years). In all, 16 underwent radial artery graft (RAG) bypass and 16 underwent superficial temporal artery (STA) bypass. 4D flow MRI, time-of-flight (TOF) magnetic resonance angiography (MRA), and computed tomography angiography (CTA) were performed. Bypass patency, flow direction, and blood flow volume (BFV) of each artery were determined by 4D flow MRI. Arterial diameters were measured by TOF-MRA and CTA. We compared RAG and STA bypasses by evaluating the flow direction and BFV of each artery. We evaluated the correlation between arterial diameters (measured by CTA or MRA) and the BFV and the detectability of flow direction (measured by 4D flow MRI) of each artery. 4D flow MRI confirmed the patency of each bypass artery. Flow direction of the M1 segment of the middle cerebral artery and BFV in the bypass artery differed between RAG and STA groups (p < 0.01). BFV in the bypass slightly correlated with the diameters on CTA (p < 0.05, R{sup 2} = 0.287). Of the 29 arteries in the circle of Willis, nine were not depicted on 4D flow MRI. Cutoff values for arterial diameters on CTA and TOF-MRA for detecting the artery on 4D flow MRI were 2.4 and 1.8 mm, respectively. 4D flow MRI provided unique information for characterizing EC-IC bypasses, although this detectability is limited when addressing small arteries with slow flow. (orig.)

  13. A TECHNOLOGY ASSESSMENT AND FEASIBILITY EVALUATION OF NATURAL GAS ENERGY FLOW MEASUREMENT ALTERNATIVES

    Energy Technology Data Exchange (ETDEWEB)

    Kendricks A. Behring II; Eric Kelner; Ali Minachi; Cecil R. Sparks; Thomas B. Morrow; Steven J. Svedeman

    1999-01-01

    Deregulation and open access in the natural gas pipeline industry has changed the gas business environment towards greater reliance on local energy flow rate measurement. What was once a large, stable, and well-defined source of natural gas is now a composite from many small suppliers with greatly varying gas compositions. Unfortunately, the traditional approach to energy flow measurement [using a gas chromatograph (GC) for composition assay in conjunction with a flow meter] is only cost effective for large capacity supplies (typically greater than 1 to 30 million scfd). A less costly approach will encourage more widespread use of energy measurement technology. In turn, the US will benefit from tighter gas inventory control, more efficient pipeline and industrial plant operations, and ultimately lower costs to the consumer. An assessment of the state and direction of technology for natural gas energy flow rate measurement is presented. The alternative technologies were ranked according to their potential to dramatically reduce capital and operating and maintenance (O and M) costs, while improving reliability and accuracy. The top-ranked technologies take an unconventional inference approach to the energy measurement problem. Because of that approach, they will not satisfy the fundamental need for composition assay, but have great potential to reduce industry reliance on the GC. Technological feasibility of the inference approach was demonstrated through the successful development of data correlations that relate energy measurement properties (molecular weight, mass-based heating value, standard density, molar ideal gross heating value, standard volumetric heating value, density, and volume-based heating value) to three inferential properties: standard sound speed, carbon dioxide concentration, and nitrogen concentration (temperature and pressure are also required for the last two). The key advantage of this approach is that inexpensive on-line sensors may be used

  14. Comparison of cardiac output determined by bioimpedance and bioreactance methods at rest and during exercise.

    Science.gov (United States)

    Jakovljevic, Djordje G; Moore, Sarah; Hallsworth, Kate; Fattakhova, Gulnar; Thoma, Christian; Trenell, Michael I

    2012-04-01

    Bioreactance is a novel non-invasive method for cardiac output measurement that involves the analysis of blood flow-dependent changes in the phase shifts of electrical currents applied across the chest. The present study (1) compared resting and exercise cardiac outputs determined by bioreactance and bioimpedance methods and those estimated from measured oxygen consumption, (2) determined the relationship between cardiac output and oxygen consumption, and (3) assessed the agreement between the bioreactance and bioimpedance methods. Twelve healthy subjects (aged 30 ± 4 years) performed graded cardiopulmonary exercise test on a recumbent cycle ergometer on two occasions, 1 week apart. Cardiac output was monitored at rest, at 30, 50, 70, 90, 150 W and at peak exercise intensity by bioreactance and bioimpedance and expired gases collected. Resting cardiac output was not significantly different between the bioreactance and bioimpedance methods (6.2 ± 1.4 vs. 6.5 ± 1.4 l min(-1), P = 0.42). During exercise cardiac outputs were correlated with oxygen uptake for both bioreactance (r = 0.84, P bioimpedance techniques (r = 0.82, P bioimpedance estimated significantly lower cardiac outputs than both bioreactance and theoretically calculated cardiac output (14.3 ± 2.6 vs. 17.5 ± 5.2 vs. 16.9 ± 4.9 l min(-1), P bioimpedance method reported ~1.5 l min(-1) lower cardiac output than bioreactance with lower and upper limits of agreement of -2.98 to 5.98 l min(-1). Bioimpedance and bioreactance methods provide different cardiac output estimates, particularly at high exercise intensity, and therefore the two methods cannot be used interchangeably. In contrast with bioimpedance, bioreactance cardiac outputs are similar to those estimated from measured oxygen consumption.

  15. Assessment of left and right ventricular diastolic and systolic functions using two-dimensional speckle-tracking echocardiography in patients with coronary slow-flow phenomenon.

    Directory of Open Access Journals (Sweden)

    Yonghuai Wang

    Full Text Available Coronary slow-flow phenomenon (CSFP is an angiographic diagnosis characterised by a low rate of flow of contrast agent in the normal or near-normal epicardial coronary arteries. Many of the patients with CSFP may experience recurrent acute coronary syndromes. However, current clinical practice tends to underestimate the impact of CSFP due to the yet unknown effect on the cardiac function. This study was performed to evaluate left ventricular (LV and right ventricular (RV diastolic and systolic functions, using two-dimensional (2D longitudinal strain and strain rate, in patients with CSFP, and to determine the relationships between the thrombolysis in myocardial infarction (TIMI frame count (TFC and LV and RV diastolic and systolic functions.Sixty-three patients with CSFP and 45 age- and sex-matched controls without CSFP were enrolled in the study. Diagnosis of CSFP was made by TFC. LV and RV diastolic and systolic functions were assessed by 2D speckle-tracking echocardiography.LV peak early diastolic longitudinal strain rate (LSRe was lower in patients with CSFP than in controls (P = 0.01. LV peak systolic longitudinal strain (LS and LV peak systolic longitudinal strain rate (LSRs were lower in patients with CSFP than in controls (P = 0.004 and P = 0.03, respectively. There was no difference in LV ejection fraction. RV peak early diastolic longitudinal strain rate (RSRe was lower in patients with CSFP than in controls (P = 0.03. There were no differences in RV peak systolic longitudinal strain (RS, RV peak systolic longitudinal strain rate (RSRs, or RV fractional area change among the groups. The mean TFC correlated negatively with LSRe and RSRe in patients with CSFP (r = -0.26, P = 0.04 and r = -0.32, P = 0.01, respectively.LV diastolic and systolic functions were impaired in patients with CSFP. CSFP also affected RV diastolic function, but not RV systolic function.

  16. TRENT2D WG: a smart web infrastructure for debris-flow modelling and hazard assessment

    Science.gov (United States)

    Zorzi, Nadia; Rosatti, Giorgio; Zugliani, Daniel; Rizzi, Alessandro; Piffer, Stefano

    2016-04-01

    Mountain regions are naturally exposed to geomorphic flows, which involve large amounts of sediments and induce significant morphological modifications. The physical complexity of this class of phenomena represents a challenging issue for modelling, leading to elaborate theoretical frameworks and sophisticated numerical techniques. In general, geomorphic-flows models proved to be valid tools in hazard assessment and management. However, model complexity seems to represent one of the main obstacles to the diffusion of advanced modelling tools between practitioners and stakeholders, although the UE Flood Directive (2007/60/EC) requires risk management and assessment to be based on "best practices and best available technologies". Furthermore, several cutting-edge models are not particularly user-friendly and multiple stand-alone software are needed to pre- and post-process modelling data. For all these reasons, users often resort to quicker and rougher approaches, leading possibly to unreliable results. Therefore, some effort seems to be necessary to overcome these drawbacks, with the purpose of supporting and encouraging a widespread diffusion of the most reliable, although sophisticated, modelling tools. With this aim, this work presents TRENT2D WG, a new smart modelling solution for the state-of-the-art model TRENT2D (Armanini et al., 2009, Rosatti and Begnudelli, 2013), which simulates debris flows and hyperconcentrated flows adopting a two-phase description over a mobile bed. TRENT2D WG is a web infrastructure joining advantages offered by the software-delivering model SaaS (Software as a Service) and by WebGIS technology and hosting a complete and user-friendly working environment for modelling. In order to develop TRENT2D WG, the model TRENT2D was converted into a service and exposed on a cloud server, transferring computational burdens from the user hardware to a high-performing server and reducing computational time. Then, the system was equipped with an

  17. Environmental-Economic Assessment Of Generation, Flow And Efficiency Of Use Of Production And Consumption Waste

    Science.gov (United States)

    Mikhailov, V. G.; Golofastova, N. N.; Galanina, T. V.; Koroleva, T. G.; Mikhailova, Ya S.

    2017-01-01

    The article deals with the issues of environmental and economic analysis of industrial and economic activities of an enterprise to assess the generation, flow and efficiency of production and consumption waste. The purpose of research is the analysis and the development of theoretical propositions for the functioning of the system of environmental and economic indicators for the effective management of production and consumption waste in the enterprise. The analysis of the existing systems of environmental and economic indicators taking into consideration the industry characteristics and the types of negative impacts is carried out. The main result of the study is the development of the system of environmental and economic indicators of production and consumption waste, adapted to the modern requirements. The results of the study can be recommended to support the effective management decision-making concerning waste management and the establishment of appropriate infrastructure.

  18. Initial assessment of facial nerve paralysis based on motion analysis using an optical flow method.

    Science.gov (United States)

    Samsudin, Wan Syahirah W; Sundaraj, Kenneth; Ahmad, Amirozi; Salleh, Hasriah

    2016-01-01

    An initial assessment method that can classify as well as categorize the severity of paralysis into one of six levels according to the House-Brackmann (HB) system based on facial landmarks motion using an Optical Flow (OF) algorithm is proposed. The desired landmarks were obtained from the video recordings of 5 normal and 3 Bell's Palsy subjects and tracked using the Kanade-Lucas-Tomasi (KLT) method. A new scoring system based on the motion analysis using area measurement is proposed. This scoring system uses the individual scores from the facial exercises and grades the paralysis based on the HB system. The proposed method has obtained promising results and may play a pivotal role towards improved rehabilitation programs for patients.

  19. External cardiac compression may be harmful in some scenarios of pulseless electrical activity.

    LENUS (Irish Health Repository)

    Hogan, T S

    2012-10-01

    Pulseless electrical activity occurs when organised or semi-organised electrical activity of the heart persists but the product of systemic vascular resistance and the increase in systemic arterial flow generated by the ejection of the left venticular stroke volume is not sufficient to produce a clinically detectable pulse. Pulseless electrical activity encompasses a very heterogeneous variety of severe circulatory shock states ranging in severity from pseudo-cardiac arrest to effective cardiac arrest. Outcomes of cardiopulmonary resuscitation for pulseless electrical activity are generally poor. Impairment of cardiac filling is the limiting factor to cardiac output in many scenarios of pulseless electrical activity, including extreme vasodilatory shock states. There is no evidence that external cardiac compression can increase cardiac output when impaired cardiac filling is the limiting factor to cardiac output. If impaired cardiac filling is the limiting factor to cardiac output and the heart is effectively ejecting all the blood returning to it, then external cardiac compression can only increase cardiac output if it increases venous return and cardiac filling. Repeated cardiac compression asynchronous with the patient\\'s cardiac cycle and raised mean intrathoracic pressure due to chest compression can be expected to reduce rather than to increase cardiac filling and therefore to reduce rather than to increase cardiac output in such circumstances. The hypothesis is proposed that the performance of external cardiac compression will have zero or negative effect on cardiac output in pulseless electrical activity when impaired cardiac filling is the limiting factor to cardiac output. External cardiac compression may be both directly and indirectly harmful to significant sub-groups of patients with pulseless electrical activity. We have neither evidence nor theory to provide comfort that external cardiac compression is not harmful in many scenarios of pulseless

  20. External cardiac compression may be harmful in some scenarios of pulseless electrical activity.

    Science.gov (United States)

    Hogan, T S

    2012-10-01

    Pulseless electrical activity occurs when organised or semi-organised electrical activity of the heart persists but the product of systemic vascular resistance and the increase in systemic arterial flow generated by the ejection of the left venticular stroke volume is not sufficient to produce a clinically detectable pulse. Pulseless electrical activity encompasses a very heterogeneous variety of severe circulatory shock states ranging in severity from pseudo-cardiac arrest to effective cardiac arrest. Outcomes of cardiopulmonary resuscitation for pulseless electrical activity are generally poor. Impairment of cardiac filling is the limiting factor to cardiac output in many scenarios of pulseless electrical activity, including extreme vasodilatory shock states. There is no evidence that external cardiac compression can increase cardiac output when impaired cardiac filling is the limiting factor to cardiac output. If impaired cardiac filling is the limiting factor to cardiac output and the heart is effectively ejecting all the blood returning to it, then external cardiac compression can only increase cardiac output if it increases venous return and cardiac filling. Repeated cardiac compression asynchronous with the patient's cardiac cycle and raised mean intrathoracic pressure due to chest compression can be expected to reduce rather than to increase cardiac filling and therefore to reduce rather than to increase cardiac output in such circumstances. The hypothesis is proposed that the performance of external cardiac compression will have zero or negative effect on cardiac output in pulseless electrical activity when impaired cardiac filling is the limiting factor to cardiac output. External cardiac compression may be both directly and indirectly harmful to significant sub-groups of patients with pulseless electrical activity. We have neither evidence nor theory to provide comfort that external cardiac compression is not harmful in many scenarios of pulseless

  1. An Assessment of a Proposed Hybrid Neural Network for Daily Flow Prediction in Arid Climate

    Directory of Open Access Journals (Sweden)

    Milad Jajarmizadeh

    2014-01-01

    Full Text Available Rainfall-runoff simulation in hydrology using artificial intelligence presents the nonlinear relationships using neural networks. In this study, a hybrid network presented as a feedforward modular neural network (FF-MNN has been developed to predict the daily rainfall-runoff of the Roodan watershed at the southern part of Iran. This FF-MNN has three layers—input, hidden, and output. The hidden layer has two types of neural expert or module. Hydrometeorological data of the catchment were collected for 21 years. Heuristic method was used to develop the MNN for exploring daily flow generalization. Two training algorithms, namely, backpropagation with momentum and Levenberg-Marquardt, were used. Sigmoid and linear transfer functions were employed to explore the network’s optimum behavior. Cross-validation and predictive uncertainty assessments were carried out to protect overtiring and overparameterization, respectively. Results showed that the FF-MNN could satisfactorily predict stream flow during testing period. The Nash-Sutcliff coefficient, coefficient of determination, and root mean square error obtained using MNN during training and test periods were 0.85, 0.85, and 39.4 and 0.57, 0.58, and 32.2, respectively. The predictive uncertainties for both periods were 0.39 and 0.44, respectively. Generally, the study showed that the FF-MNN can give promising prediction for rainfall-runoff relations.

  2. A new flow cytometric method for quantitative assessment of lymphocyte mitogenic potentials.

    Science.gov (United States)

    Yamamura, Y; Rodriguez, N; Schwartz, A; Eylar, E; Bagwell, B; Yano, N

    1995-01-01

    A new flow cytometric method was developed to quantitatively assess lymphocyte proliferation simultaneously for different subsets. The cells were stained with a fluorescent dye, PKH-26 and were stimulated with mitogens. The fluorescence intensities (FL2) of proliferating cells were measured by flow cytometry; and each subset was identified by the use of a monoclonal antibody (Mab)-fluorescein-isothiocyanate (FITC) (FL1). FL2 histograms were then analyzed by the cell proliferation model based on the ModFit software (Verity). This new method revealed information which could not be obtained by conventional mitogen assays. For example, the CD4+ and the CD4- T-subsets responded to phytohemagglutinin (PHA) quite differently from each other and it was indicated that activation of one population could significantly alter the response of the other. In addition, even within a subset, all activated cells did not proliferate uniformly. Some cells divided only once while others underwent further cellular division during the same time period. The method is, therefore, invaluable for studying the nature and the extent of interactions between different cellular subsets within a culture.

  3. Comparative assessment of SAS and DES turbulence modeling for massively separated flows

    Science.gov (United States)

    Zheng, Weilin; Yan, Chao; Liu, Hongkang; Luo, Dahai

    2016-02-01

    Numerical studies of the flow past a circular cylinder at Reynolds number 1.4× 105 and NACA0021 airfoil at the angle of attack 60° have been carried out by scale-adaptive simulation (SAS) and detached eddy simulation (DES), in comparison with the existing experimental data. The new version of the model developed by Egorov and Menter is assessed, and advantages and disadvantages of the SAS simulation are analyzed in detail to provide guidance for industrial application in the future. Moreover, the mechanism of the scale-adaptive characteristics in separated regions is discussed, which is obscure in previous analyses. It is concluded that: the mean flow properties satisfactorily agree with the experimental results for the SAS simulation, although the prediction of the second order turbulent statistics in the near wake region is just reasonable. The SAS model can produce a larger magnitude of the turbulent kinetic energy in the recirculation bubble, and, consequently, a smaller recirculation region and a more rapid recovery of the mean velocity outside the recirculation region than the DES approach with the same grid resolution. The vortex shedding is slightly less irregular with the SAS model than with the DES approach, probably due to the higher dissipation of the SAS simulation under the condition of the coarse mesh.

  4. Influence of routine assessment of fractional flow reserve on decision making during coronary interventions.

    Science.gov (United States)

    Sant'Anna, Fernando M; Silva, Expedito E R; Batista, Leonardo Alves; Ventura, Fábio Machado; Barrozo, Carlos Alberto Mussel; Pijls, Nico H J

    2007-02-15

    In complex coronary artery disease, it is sometimes difficult to determine which lesions are associated with reversible ischemia and should be stented. Fractional flow reserve (FFR) is an established objective methodology to indicate which lesions produce ischemia. Despite this, the selection of lesions to be stented is often based on the subjectively interpreted angiogram alone. The aim of this study in patients admitted for elective percutaneous intervention (PCI) was to evaluate the change in strategy if the decision to intervene was based on FFR measurement rather than on angiographic assessment. Two hundred fifty consecutive patients (471 arteries) scheduled for PCI were included in this study. All stenoses >or=50% by visual estimation and initially selected to be stented by 3 independent reviewers were assessed by FFR measurements. If FFR was or=0.75, no interventional treatment was given. Optimal pressure measurements were obtained in 452 lesions (96%). Diameter stenosis was 62 +/- 12%, and FFR was 0.67 +/- 0.17 for the entire group. In 68% of the stenoses, initial strategy as assessed from the angiogram was followed, and in 32%, there was a change in the planned approach based on FFR. In 48% of the patients, there was >or=1 lesion in which the treatment decision was changed after physiologic measurements. In conclusion, in this prospective, nonselective, but complete study representing the real world of PCI, 32% of the coronary stenoses and 48% of patients would have received a different treatment if the decision had been based on angiography only, stressing the utility of physiologic assessment in refining decision making during PCI.

  5. Flow Cytometric Assessment of Bacterial Abundance in Soils, Sediments and Sludge.

    Science.gov (United States)

    Frossard, Aline; Hammes, Frederik; Gessner, Mark O

    2016-01-01

    Bacterial abundance is a fundamental measure in microbiology, but its assessment is often tedious, especially for soil, and sediment samples. To overcome this limitation, we adopted a time-efficient flow-cytometric (FCM) counting method involving cell detachment and separation from matrix particles by centrifugation in tubes receiving sample suspensions and Histodenz(®) solution. We used this approach to assess bacterial abundances in diverse soils (natural and agricultural), sediments (streams and lakes) and sludge from sand-filters in a drinking water treatment plant and compared the results to bacterial abundances determined by two established methods, epifluorescence microscopy (EM) and adenosine triphosphate (ATP) quantification. Cell abundances determined by FCM and EM correlated fairly well, although absolute cell abundances were generally lower when determined by FCM. FCM also showed significant relations with cell counts converted from ATP concentrations, although estimates derived from ATP determinations were typically higher, indicating the presence of ATP sources other than bacteria. Soil and sediment organic matter (OM) content influenced the goodness of fit between counts obtained with EM and FCM. In particular, bacterial abundance determined by FCM in samples containing less than 10% OM, such as stream sediment, was particularly well correlated with the cell counts assessed by EM. Overall, these results suggest that FCM following cell detachment and purification is a useful approach to increase sample throughput for determining bacterial abundances in soils, sediments and sludge. However, notable scatter and only partial concordance among the FCM and reference methods suggests that protocols require further improvement for assessments requiring high precision, especially when OM contents in samples are high.

  6. Cardiac tamponade (image)

    Science.gov (United States)

    Cardiac tamponade is a condition involving compression of the heart caused by blood or fluid accumulation in the space ... they cannot adequately fill or pump blood. Cardiac tamponade is an emergency condition that requires hospitalization.

  7. What Is Cardiac Rehabilitation?

    Science.gov (United States)

    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 ...

  8. Investigation and Assessment of Landslides and Debris Flows in Sichuan Province of China by Remote Sensing Technique

    Institute of Scientific and Technical Information of China (English)

    ZHANG Baolei; ZHANG Shumin; ZHOU Wancun

    2006-01-01

    Taking TM images, ETM images, SPOT images, aerial photos and other remote sensing data as fundamental sources, this research makes a thorough investigation on landslides and debris flows in Sichuan Province, China, using spectral matching, and image mosaic. And then, the spatial characteristics of landslides and debris flows in the year of 2005 are assessed and made into figures. The environmental factors which induce landslides and debris flows such as slope, vegetation coverage, lithology, rainfall and so on are obtained by GIS spatial analysis method. Finally, the relationships of landslides or debris flows with some environmental factors are analyzed based on the grade of each environmental factor. The results indicate: 1) The landslides and debris flows are mainly in the eastern and southern area of Sichuan Province, however, there are few landslides and debris flows in the western particularly the northwestern Sichuan. 2) The landslides and debris flows of Sichuan Province are mostly located in the regions with small slope degree.The occurring rate of debris flow reduces with the increase of the vegetation coverage degree, but the vegetation coverage degree has little to do with the occurrence of landslide. The more rainfall a place has, the easier the landslides and debris flows take place.

  9. A new method of providing pulsatile flow in a centrifugal pump: assessment of pulsatility using a mock circulatory system.

    Science.gov (United States)

    Herreros, Jesús; Berjano, Enrique J; Sales-Nebot, Laura; Más, Pedro; Calvo, Irene; Mastrobuoni, Stefano; Mercé, Salvador

    2008-06-01

    Previous studies have demonstrated the potential advantages of pulsatile flow as compared with continuous flow. However, to date, physiologic pumps have been technically complex and their application has therefore remained in the experimental field. We have developed a new type of centrifugal pump, which can provide pulsatile as well as continuous flow. The inner wall of a centrifugal pump is pulsed by means of a flexible membrane, which can be accurately controlled by means of either a hydraulic or pneumatic driver. The aim of this study was to assess the hydraulic behavior of the new pump in terms of surplus hemodynamic energy (SHE). We conducted experiments using a mock circulatory system including a membrane oxygenator. No differences were found in the pressure-flow characteristics between the new pump and a conventional centrifugal pump, suggesting that the inclusion of the flexible membrane does not alter hydraulic performance. The value of SHE rose when systolic volume was increased. However, SHE dropped when the percentage of ejection time was reduced and also when the continuous flow (programmed by the centrifugal console) increased. Mean flow matched well with the continuous flow set by the centrifugal console, that is, the pulsatile component of the flow was exclusively controlled by the pulsatile console, and was therefore independent of the continuous flow programmed by the centrifugal console. The pulsatility of the new pump was approximately 25% of that created with a truly pulsatile pump.

  10. A comparative assessment of two different debris flow propagation approaches - blind simulations on a real debris flow event

    Science.gov (United States)

    Stancanelli, L. M.; Foti, E.

    2015-04-01

    A detailed comparison between the performances of two different approaches to debris flow modelling was carried out. In particular, the results of a mono-phase Bingham model (FLO-2D) and that of a two-phase model (TRENT-2D) obtained from a blind test were compared. As a benchmark test the catastrophic event of 1 October 2009 which struck Sicily causing several fatalities and damage was chosen. The predicted temporal evolution of several parameters of the debris flow (such as flow depth and propagation velocity) was analysed in order to investigate the advantages and disadvantages of the two models in reproducing the global dynamics of the event. An analysis between the models' results with survey data have been carried out, not only for the determination of statistical indicators of prediction accuracy, but also for the application of the Receiver Operator Characteristic (ROC) approach. Provided that the proper rheological parameters and boundary conditions are assigned, both models seem capable of reproducing the inundation areas in a reasonably accurate way. However, the main differences in the application rely on the choice of such rheological parameters. Indeed, within the more user-friendly FLO-2D model the tuning of the parameters must be done empirically, with no evidence of the physics of the phenomena. On the other hand, for the TRENT-2D the parameters are physically based and can be estimated from the properties of the solid material, thus reproducing more reliable results. A second important difference between the two models is that in the first method the debris flow is treated as a homogeneous flow, in which the total mass is kept constant from its initiation in the upper part of the basin to the deposition in a debris fan. In contrast, the second approach is suited to reproduce the erosion and deposition processes and the displaced mass can be directly related to the rainfall event. Application of both models in a highly urbanized area reveals the

  11. A comparative assessment of two different debris flow propagation approaches – blind simulations on a real debris flow event

    Directory of Open Access Journals (Sweden)

    L. M. Stancanelli

    2014-11-01

    Full Text Available A detailed comparison between the performances of two different approaches to debris flow modelling has been carried out. In particular, the results of a mono-phase Bingham model (FLO-2D and these of a two phase model (TRENT-2D obtained from a blind test have been compared. As a benchmark test the catastrophic event of 1 October 2009 which struck Sicily causing several fatalities and damages has been chosen. The predicted temporal evolution of several parameters of the debris flow (as the flow depths and the propagation velocities has been analyzed in order to investigate the advantages and disadvantages of the two models in reproducing the global dynamics of the event. Analysis between the models results with survey data have been carried out, not only for the determination of statistical indicators of prediction accuracy, but also for the application of the Receiver Operator Characteristic (ROC approach. Provided that the proper rheological parameters and boundary conditions are assigned, both models seem capable of reproducing the inundation areas in a fairly good way. However, the main differences in the application rely in the choice of such rheological parameters. Indeed, within the more user friendly FLO-2D model the tuning of the parameters must be done empirically, with no evidence of the physics of the phenomena. On the other hand, for the TRENT-2D the parameters are physically based and can be estimated from the properties of the solid material, thus reproducing more reliable results. A second important difference between the two models is that in the first method the debris flow is treated as homogeneous flow, in which the total mass is kept constant from initiation in the upper part of the basin up to the deposition on debris fan. On the contrary, the second approach is suite to reproduce the erosion and deposition processes and the displaced mass can be directly related to the rainfall event. Application of both models in an highly

  12. Future Flows Hydrology: an ensemble of daily river flow and monthly groundwater levels for use for climate change impact assessment across Great Britain

    Directory of Open Access Journals (Sweden)

    C. Prudhomme

    2012-12-01

    Full Text Available The dataset Future Flows Hydrology was developed as part of the project "Future Flows and Groundwater Levels" to provide a consistent set of transient daily river flow and monthly groundwater levels projections across England, Wales and Scotland to enable the investigation of the role of climate variability on river flow and groundwater levels nationally and how this may change in the future.

    Future Flows Hydrology is derived from Future Flows Climate, a national ensemble projection derived from the Hadley Centre's ensemble projection HadRM3-PPE to provide a consistent set of climate change projections for the whole of Great Britain at both space and time resolutions appropriate for hydrological applications. Three hydrological models and one groundwater level model were used to derive Future Flows Hydrology, with 30 river sites simulated by two hydrological models to enable assessment of hydrological modelling uncertainty in studying the impact of climate change on the hydrology.

    Future Flows Hydrology contains an 11-member ensemble of transient projections from January 1951 to December 2098, each associated with a single realisation from a different variant of HadRM3 and a single hydrological model. Daily river flows are provided for 281 river catchments and monthly groundwater levels at 24 boreholes as .csv files containing all 11 ensemble members. When separate simulations are done with two hydrological models, two separate .csv files are provided.

    Because of potential biases in the climate-hydrology modelling chain, catchment fact sheets are associated with each ensemble. These contain information on the uncertainty associated with the hydrological modelling when driven using observed climate and Future Flows Climate for a period representative of the reference time slice 1961–1990 as described by key hydrological statistics. Graphs of projected changes for selected hydrological indicators are also provided for

  13. Future Flows Hydrology: an ensemble of daily river flow and monthly groundwater levels for use for climate change impact assessment across Great Britain

    Directory of Open Access Journals (Sweden)

    C. Prudhomme

    2013-03-01

    Full Text Available The dataset Future Flows Hydrology was developed as part of the project "Future Flows and Groundwater Levels'' to provide a consistent set of transient daily river flow and monthly groundwater level projections across England, Wales and Scotland to enable the investigation of the role of climate variability on river