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Sample records for cardiac output assessment

  1. Cardiac Output Assessed by Invasive and Minimally Invasive Techniques

    PubMed Central

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

    2011-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2009-04-01

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

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

    PubMed

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

    2009-04-01

    Automatic segmentation of the endocardial surface in three-dimensional (3D) echocardiographic images is an important tool to assess left ventricular (LV) geometry and cardiac output (CO). The presence of speckle noise as well as the nonisotropic characteristics of the myocardium impose strong demands on the segmentation algorithm. In the analysis of normal heart geometries of standardized (apical) views, it is advantageous to incorporate a priori knowledge about the shape and appearance of the heart. In contrast, when analyzing abnormal heart geometries, for example in children with congenital malformations, this a priori knowledge about the shape and anatomy of the LV might induce erroneous segmentation results. This study describes a fully automated segmentation method for the analysis of non-standard echocardiographic images, without making strong assumptions on the shape and appearance of the heart. The method was validated in vivo in a piglet model. Real-time 3D echocardiographic image sequences of five piglets were acquired in radiofrequency (rf) format. These ECG-gated full volume images were acquired intra-operatively in a non-standard view. Cardiac blood flow was measured simultaneously by an ultrasound transit time flow probe positioned around the common pulmonary artery. Three-dimensional adaptive filtering using the characteristics of speckle was performed on the demodulated rf data to reduce the influence of speckle noise and to optimize the distinction between blood and myocardium. A gradient-based 3D deformable simplex mesh was then used to segment the endocardial surface. A gradient and a speed force were included as external forces of the model. To balance data fitting and mesh regularity, one fixed set of weighting parameters of internal, gradient and speed forces was used for all data sets. End-diastolic and end-systolic volumes were computed from the segmented endocardial surface. The cardiac output derived from this automatic segmentation was validated quantitatively by comparing it with the CO values measured from the volume flow in the pulmonary artery. Relative bias varied between 0 and -17%, where the nominal accuracy of the flow meter is in the order of 10%. Assuming the CO measurements from the flow probe as a gold standard, excellent correlation (r = 0.99) was observed with the CO estimates obtained from image segmentation. PMID:19265202

  4. Low cardiac output syndrome: identification and management.

    PubMed

    Mass, Linda; Antonacci, Marie

    2005-12-01

    Low cardiac output syndrome (LCOS) is a clinical condition that is caused by a transient decrease in systemic perfusion secondary to myocardial dysfunction. The outcome is an imbalance between oxygen delivery and oxygen consumption at the cellular level which leads to metabolic acidosis. Although LCOS is observed most commonly in patients after cardiac surgery, it may present in various disease processes resulting in cardiac dysfunction. This article provides an overview of the determinants involved in oxygen transport, the physiologic factors influencing cardiovascular function, the assessment of hemodynamic variables, the etiology of LCOS, and management strategies, including a brief review of some pharmacologic agents that are used in the treatment of low cardiac output. PMID:16344207

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

    SciTech Connect

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

    1985-05-01

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

  6. Mathematics and the Heart: Understanding Cardiac Output

    ERIC Educational Resources Information Center

    Champanerkar, Jyoti

    2013-01-01

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

  7. Mathematics and the Heart: Understanding Cardiac Output

    ERIC Educational Resources Information Center

    Champanerkar, Jyoti

    2013-01-01

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

  8. Methods in pharmacology: measurement of cardiac output

    PubMed Central

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

    2011-01-01

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

  9. Evaluation of noninvasive cardiac output methods during exercise

    NASA Technical Reports Server (NTRS)

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

    1992-01-01

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

  10. Methods and apparatus for determining cardiac output

    NASA Technical Reports Server (NTRS)

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

    2010-01-01

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

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

    PubMed Central

    Perrino, A. C.

    1993-01-01

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

  12. Reduced cardiac output in imported Plasmodium falciparum malaria

    PubMed Central

    2011-01-01

    Background Volume substitution remains subject of controversy in the light of effusions and oedema potentially complicating this highly febrile disease. Understanding the role of myocardial and circulatory function appears to be essential for clinical management. In the present study, cardiac function and cardiac proteins have been assessed and correlated with parasitological and immunologic parameters in patients with imported Plasmodium falciparum malaria. Methods In a prospective case-control study, 28 patients with uncomplicated and complicated P. falciparum malaria were included and findings were compared with 26 healthy controls. Cardiac function parameters were assessed by an innovative non-invasive method based on the re-breathing technique. In addition, cardiac enzymes and pro- and anti-inflammatory cytokines were measured and assessed with respect to clinical symptoms and conditions of malaria. Results Cardiac index (CI) as a measurement of cardiac output (CO) was 21% lower in malaria patients than in healthy controls (2.7 l/min/m2 versus 3.4 l/min/m2; P < 0.001). In contrast, systemic vascular resistance index (SVRI) was increased by 29% (32.6 mmHg?m2/(l/min) versus 23.2 mmHg?m2/(l/min); P < 0.001). This correlated with increased cardiac proteins in patients versus controls: pro-BNP 139.3 pg/ml versus 60.4 pg/ml (P = 0.03), myoglobin 43.6 ?g/l versus 27.8 ?g/l (P = < 0.001). All measured cytokines were significantly increased in patients with malaria. CI, SVRI as well as cytokine levels did not correlate with blood parasite density. Conclusions The results support previous reports suggesting impaired cardiac function contributing to clinical manifestations in P. falciparum malaria. Findings may be relevant for fluid management and should be further explored in endemic regions. PMID:21658247

  13. Regulation of cardiac output in hypoxia.

    PubMed

    Siebenmann, Christoph; Lundby, Carsten

    2015-12-01

    This brief review addresses the regulation of cardiac output (Q) at rest and during submaximal exercise in acute and chronic hypoxia. To preserve systemic O2 delivery in acute hypoxia Q is increased by an acceleration of heart rate, whereas stroke volume (SV) remains unchanged. Tachycardia is governed by activation of carotid and aortic chemoreceptors and a concomitant reduction in arterial baroreflex activation, all balancing sympathovagal activity toward sympathetic dominance. As hypoxia extends over several days a combination of different adaptive processes restores arterial O2 content to or beyond sea level values and hence Q normalizes. The latter however occurs as a consequence of a decrease in SV whereas tachycardia persists. The diminished SV reflects a lower left ventricular end-diastolic volume which is primarily related to hypoxia-generated reduction in plasma volume. Hypoxic pulmonary vasoconstriction may contribute by increasing right ventricular afterload and thus decreasing its ejection fraction. In summary, the Q response to hypoxia is the result of a complex interplay between several physiological mechanisms. Future studies are encouraged to establish the individual contributions of the different components from an integrative perspective. PMID:26589118

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

    PubMed

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

    2015-04-01

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

  15. [Echocardiography in emergency admissions. Recognition of cardiac low-output failure].

    PubMed

    Schmidt, J; Maier, A; Christ, M

    2012-10-01

    Detection of acute cardiac dysfunction and differential diagnosis of low cardiac output syndrome is challenging for emergency physicians. For the critical ill patient it is essential to rapidly identify the underlying disease to initiate the correct therapy and optimize patient outcome. Echocardiography is the diagnostic tool of choice for the evaluation of low cardiac output states. In the setting of the emergency department the use of focused echocardiography instead of detailed echocardiographic studies of cardiologists is appropriate and should be provided for emergency care. The differentiation in preserved versus reduced left ventricular ejection fraction as a first assessment is helpful, particularly for physicians not well trained in echocardiography. The structured and focused approach to evaluate or exclude differential diagnoses of cardiac dysfunction is the key for optimal management of acute and critically ill patients with low cardiac output. PMID:23052991

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

    PubMed Central

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

    1990-01-01

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

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

    SciTech Connect

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

    1989-10-01

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

  18. Pulmonary Vasodilators in the Management of Low Cardiac Output Syndrome After Pediatric Cardiac Surgery.

    PubMed

    Avila-Alvarez, Alejandro; Del Cerro Marin, Maria Jesus; Bautista-Hernandez, Victor

    2016-01-01

    Pulmonary hypertension is among the causes of low cardiac output syndrome after neonatal and pediatric cardiac surgery. In the setting of transient postoperative myocardial dysfunction, even a moderate elevation of pulmonary pressure can result in heart dysfunction and circulatory collapse. Although, specific pharmacological manipulation of pulmonary vascular resistance is frequently required in the perioperative period, there is no widely standardized management. In this review, a systematic literature search of PubMed and MEDLINE databases using relevant terms was performed. All clinical trials and relevant manuscripts, along with important physiological, pharmacological, and evidence-based considerations involving the use of pulmonary vasodilators in the management of low cardiac output syndrome after cardiac surgery were reviewed. This article addresses the fifth of eight topics comprising the special issue entitled "Pharmacologic strategies with afterload reduction in low cardiac output syndrome after pediatric cardiac surgery". PMID:26463986

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

    PubMed Central

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

    2015-01-01

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

  20. Cardiac output during excitation of chemoreflexes in the cat

    PubMed Central

    Barer, Gwenda R.; Nsser, E.

    1958-01-01

    In cats under chloralose anaesthesia the reflex fall of blood pressure and heart rate caused by injection of veratrine, amidines, diphenhydramine, or ethyl acetoacetate was accompanied by a fall in cardiac output. After veratrine and amidines there was a fall in mean pulmonary arterial pressure and after veratrine no significant change in pulmonary vascular resistance. After diphenhydramine and ethyl acetoacetate there was a rise in mean pulmonary arterial pressure and after diphenhydramine an increase in pulmonary vascular resistance. The effects of veratrine and amidines, but not those of diphenhydramine and ethyl acetoacetate, were abolished by section of the vagi. The main change leading to the fall of cardiac output after amidines was bradycardia. PMID:13618538

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

    SciTech Connect

    Yee, Seonghwan; Scalzetti, Ernest M.

    2014-06-15

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

  2. [Analysis of empyrical factors for the determination of cardiac output].

    PubMed

    Herrera, E L; Terwes, E; Song Sang, Y P; Prefant, C; Anthonisen, N R

    1978-01-01

    With a method by which no recirculation was possible the area of a dilution curve was obtained. On this basis it was searched what percentage represents the forward triangle of the total surface of the curve. The rle of the V/F of the sampling system on this portion of the curve was studied, surface from which the empirical constants for the estimation of the cardiac output derivates. The data obtained suggest that the forward surface triangle was V/F dependent V/F less than 1 gave smaller forward triangles, the opposite was true with V/F greater than 1. It was also found that V/F greater than 1 subestimate the total surface of the dye curve, which means cardiac outputs higher than the real. The forward surface of the curve was reduced to a minimal percentage of the total curve when a V/F less than 1 was used. Situation that makes this area non useful to obtain from them empirical factors. If an empirical factor is use in order to measure cardiac output it had to be accepted that an important grade of error is introduced. PMID:697453

  3. Cellular and Molecular Mechanisms of Low Cardiac Output Syndrome after Pediatric Cardiac Surgery.

    PubMed

    Bautista-Hernandez, Victor; Karamanlidis, Georgios; McCully, James D; Del Nido, Pedro J

    2016-01-01

    Several cellular and molecular mechanisms have been implicated in the development of myocardial dysfunction and low cardiac output in pediatric patients undergoing heart surgery. Ischemia- reperfusion injury with alterations in calcium homeostasis as well as mitochondrial function has been strongly related to myocyte damage and heart failure in this population. In this article, we will review the main mechanisms of postoperative cardiac dysfunction at cellular and molecular levels and the subsequent protective strategies. In addition, we will describe cellular features of the neonatal or immature myocardium and will suggest possible protective management strategies. This article addresses the first of eight topics comprising the special issue entitled "Pharmacologic strategies with afterload reduction in low cardiac output syndrome after pediatric cardiac surgery". PMID:26463990

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

    PubMed Central

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

    2014-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2008-06-01

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

  6. Validation of stroke volume and cardiac output by electrical interrogation of the brachial artery in normals: assessment of strengths, limitations, and sources of error.

    PubMed

    Bernstein, Donald P; Henry, Isaac C; Lemmens, Harry J; Chaltas, Janell L; DeMaria, Anthony N; Moon, James B; Kahn, Andrew M

    2015-12-01

    The goal of this study is to validate a new, continuous, noninvasive stroke volume (SV) method, known as transbrachial electrical bioimpedance velocimetry (TBEV). TBEV SV was compared to SV obtained by cardiac magnetic resonance imaging (cMRI) in normal humans devoid of clinically apparent heart disease. Thirty-two (32) volunteers were enrolled in the study. Each subject was evaluated by echocardiography to assure that no aortic or mitral valve disease was present. Subsequently, each subject underwent electrical interrogation of the brachial artery by means of a high frequency, low amplitude alternating current. A first TBEV SV estimate was obtained. Immediately after the initial TBEV study, subjects underwent cMRI, using steady-state precession imaging to obtain a volumetric estimate of SV. Following cMRI, the TBEV SV study was repeated. Comparing the cMRI-derived SV to that of TBEV, the two TBEV estimates were averaged and compared to the cMRI standard. CO was computed as the product of SV and heart rate. Statistical methods consisted of Bland-Altman and linear regression analysis. TBEV SV and CO estimates were obtained in 30 of the 32 subjects enrolled. Bland-Altman analysis of pre- and post-cMRI TBEV SV showed a mean bias of 2.87 % (2.05mL), precision of 13.59% (11.99mL) and 95% limits of agreement (LOA) of +29.51% (25.55mL) and -23.77% (-21.45mL). Regression analysis for pre- and post-cMRI TBEV SV values yielded y=0.76x+25.1 and r(2)=0.71 (r=0.84). Bland-Altman analysis comparing cMRI SV with averaged TBEV SV showed a mean bias of -1.56% (-1.53mL), precision of 13.47% (12.84mL), 95% LOA of +24.85% (+23.64mL) and -27.97% (-26.7mL) and percent error=26.2%. For correlation analysis, the regression equation was y=0.82x+19.1 and correlation coefficient r(2)=0.61 (r=0.78). Bland-Altman analysis of averaged pre- and post-cMRI TBEV CO versus cMRI CO yielded a mean bias of 5.01% (0.32Lmin(-1)), precision of 12.85% (0.77Lmin(-1)), 95% LOA of +30.20% (+0.1.83Lmin(-1)) and -20.7% (-1.19Lmin(-1)) and percent error=24.8%. Regression analysis yielded y=0.92x+0.78, correlation coefficient r(2)=0.74 (r=0.86). TBEV is a novel, noninvasive method, which provides satisfactory estimates of SV and CO in normal humans. PMID:25682204

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

    PubMed Central

    Liang, Chang-Seng; Hood, William B.

    1973-01-01

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

  8. Continuous monitoring of cardiac output from TCG signals.

    PubMed

    Keenan, D B

    2004-01-01

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

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

    PubMed

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

    1985-06-01

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

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

    PubMed

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

    2016-02-01

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

  11. Measurement of cardiac output by use of noninvasively measured transient hemodilution curves with photoacoustic technology

    PubMed Central

    Kang, Dongyel; Huang, Qiaojian; Li, Youzhi

    2014-01-01

    We present the theoretical basis and experimental verification for cardiac output measurements using noninvasively measured hemodilution curves afforded with an indicator dilution technique and the emerging photoacoustic technology. A photoacoustic system noninvasively tracks a transient hemodilution effect induced by a bolus of isotonic saline as an indicator. As a result, a photoacoustic indicator dilution curve is obtained, which allows to estimate cardiac output from the developed algorithm. The experiments with a porcine blood circulatory phantom system demonstrated the feasibility of this technology towards the development of a noninvasive cardiac output measurement system for patient monitoring. PMID:24877007

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

    NASA Technical Reports Server (NTRS)

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

    1973-01-01

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

  13. Non-invasive determination of cardiac output by Doppler echocardiography and electrical bioimpedance.

    PubMed Central

    Northridge, D B; Findlay, I N; Wilson, J; Henderson, E; Dargie, H J

    1990-01-01

    Cardiac output measured by thermodilution in 25 patients within 24 hours of acute myocardial infarction was compared with cardiac output measured by Doppler echocardiography (24 patients) and electrical bioimpedance (25 patients). The mean (range) cardiac outputs measured by Doppler (4.03 (2.2-6.0) 1/min) and electrical bioimpedance (3.79 (1.1-6.2) 1/min) were similar to the mean thermodilution value (3.95 (2.1-6.2) 1/min). Both non-invasive techniques agreed closely with thermodilution in most patients. None the less, three results with each method disagreed with thermodilution by more than 1 1/min. Both non-invasive techniques were reproducible and accurate in most patients with acute myocardial infarction. Doppler echocardiography was time consuming and technically demanding. Electrical bioimpedance was simple to use and had the additional advantage of allowing continuous monitoring of the cardiac output. PMID:2317415

  14. Volume loading improves low cardiac output in experimental right ventricular infarction. [Dogs

    SciTech Connect

    Goldstein, J.A.; Vlahakes, G.J.; Verrier, E.D.; Schiller, N.B.; Botvinick, E.; Tyberg, J.V.; Parmley, W.W.; Chatterjee, K.

    1983-08-01

    To evaluate the effect of volume loading in the low output state associated with right ventricular infarction, isolated right ventricular infarction was produced in seven dogs with the pericardium intact. Volume loading and pericardiotomy were then sequentially performed. After the production of right ventricular infarction, right ventricular systolic pressure decreased by 25%, aortic pressure by 36% and cardiac output by 32%. Right ventricular ejection fraction decreased by 57%, but left ventricular ejection fraction did not change significantly. Left ventricular transmural pressure and diastolic size decreased, and right ventricular diastolic size increased. Intrapericardial pressure increased and equalization of diastolic pressures was noted. Volume loading resulted in increased right ventricular systolic pressure and stroke work, increased aortic pressure and cardiac output and increased transmural pressure and diastolic size in both ventricles. Pericardiotomy resulted in further increases in right and left ventricular filling, stroke work and cardiac output, as well as resolution of equalized diastolic pressures. These results indicate that cardiac output in experimental right ventricular infarction increases with volume loading, which enhances left ventricular preload by augmenting right ventricular output. Elevated intrapericardial pressure affects filling of both ventricles and may play a role in the pathophysiology of low cardiac output in right ventricular infarction.

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

    PubMed

    Jonas, Max M; Tanser, Suzie J

    2002-06-01

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

  16. Echocardiographic assessment of cardiac disease

    NASA Technical Reports Server (NTRS)

    Popp, R. L.

    1976-01-01

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

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

    PubMed Central

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

    2006-01-01

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

  18. Cardiac Output as a Potential Risk Factor for Abnormal Brain Aging

    PubMed Central

    Jefferson, Angela L.

    2011-01-01

    Heart failure has served as a clinically useful model for understanding how cardiac dysfunction is associated with neuroanatomic and neuropsychological changes in aging adults, theoretically because systemic hypoperfusion disrupts cerebral perfusion, contributing to clinical brain injury. This review summarizes more recent data suggesting that subtle cardiac dysfunction or low normal levels of cardiac function, as quantified by cardiac output, are related to cognitive and neuroimaging markers of abnormal brain aging in the absence of heart failure or severe cardiomyopathy. Additional work is required, but such associations suggest that reduced cardiac output may be a risk factor for Alzheimers disease (AD) and abnormal brain aging through the propagation or exacerbation of neurovascular processes, microembolism due to thrombosis, and AD neuropathological processes. Such mechanistic pathways are discussed in the context of a theoretical model that posits a direct pathway of injury between cardiac output and abnormal brain aging (i.e., reduced systemic blood flow disrupts cerebral blood flow homeostasis), contributing to clinical brain injury, independent of shared risk factors for both cardiac dysfunction and abnormal brain aging. PMID:20413856

  19. Pathophysiology of Neurally Mediated Syncope: Role of Cardiac Output and Total Peripheral Resistance

    PubMed Central

    Fu, Qi; Levine, Benjamin D.

    2014-01-01

    Syncope is a common clinical condition occurring even in otherwise healthy people without underlying cardiovascular disease. Neurally mediated syncope is by far the the most common cause of syncope in individuals without any structural heart disease. Based on traditional wisdom, loss of sympathetic tone with relaxation of vascular smooth muscle is the key mechanism underlying the pathophysiology of syncope, especially in patients without an acute decrease in heart rate. However, this concept has recently been challenged. Some microneurographic studies indicate that sympathetic withdrawal may not always be a prerequisite even for the development of classic vasodepressor forms of syncope. Conversely, a decrease in cardiac output appears to be a determinant factor for syncope in most circumstances. This article reviews the relative contribution of cardiac output versus sympathetic vasoconstriction in neurally mediated syncope in otherwise healthy individuals. It is suggested that a moderate to severe fall in cardiac output with or without vasodilatation may contribute to syncope. PMID:25081417

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

    NASA Astrophysics Data System (ADS)

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

    2004-07-01

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

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

    PubMed Central

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

    2013-01-01

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

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

    NASA Technical Reports Server (NTRS)

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

    1975-01-01

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

  3. Reproducibility of cardiac output measurements by Doppler echocardiography in prepubertal children and adults.

    PubMed

    Vinet, A; Nottin, S; Lecoq, A M; Guenon, P; Obert, P

    2001-08-01

    The aim of this study was to examine reproducibility of stroke volume and cardiac output measurements by Doppler echocardiography during submaximal and maximal exercise in adults and children. Fourteen healthy children (8 girls and 6 boys aged 10.9 +/- 0.9yr) and eleven healthy young adults (1 female and 10 males aged 22.3 +/- 3.8 yr) underwent a progressive maximal upright cycle test until exhaustion with estimation of stroke volume and cardiac output by Doppler echocardiography on two separate occasions (one week apart). Maximal oxygen uptake and maximal heart rate were not significantly different between both tests in the children and adults indicating that similar exhaustive efforts were achieved at each test. No significant differences for mean values of stroke volume and cardiac output were observed at rest in the children and whatever the exercise intensity in the children and adults. No significant differences were observed between values of root mean square (precision and precision of error) in both groups. Thus we demonstrated that stroke volume and cardiac output values obtained by Doppler echocardiography at rest and during submaximal and maximal exercise were reproducible on test-retest measurements in children and adults. PMID:11531037

  4. Effect of region of interest selection on first-pass radionuclide cardiac output determination

    SciTech Connect

    Glass, E.C.; Rahimian, J.; Hines, H.H.

    1986-08-01

    In principle, region of interest (ROI) selection should not affect the measurement of cardiac output by the first-pass technique with a radioactive intravascular indicator. Clinical application of the method requires that this theoretical hypothesis be tested. Sixty-eight left anterior oblique first-pass studies were acquired with a scintillation camera and computer using red blood cells labeled in vitro with /sup 99m/Tc. Calculated mean cardiac output varied in the following order with respect to ROI: lung greater than right heart greater than left ventricle greater than whole heart (both ventricles) greater than aorta. Similar variations were observed in patients both with and without valvular regurgitation. Regions of interest over left ventricle or whole heart yielded the best correlations with cardiac output by thermodilution (r = 0.96, 0.95, respectively, n = 28) as well as the smallest interobserver variations (r = 0.994, 0.995, respectively, n = 33). First-pass studies with (/sup 99m/Tc)red blood cells labeled in vitro can yield accurate, reproducible determinations of cardiac output provided that the effect of ROI selection is recognized and that regions are properly selected.

  5. Effect of Hemorrhage on Cardiac Output, PVP, Alodosterone and Diuresis during Immersion in Men

    NASA Technical Reports Server (NTRS)

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

    1990-01-01

    The purpose of this study was to test the hypothesis that a reduction in blood volume would attenuate or eliminate immersion-induced increases in cardiac output (Q (sup dot) sub co)) and urine excretion, and to investigate accompanying vasoactive and fluid-electrolyte hormonal responses.

  6. Cardiac output distribution and uteroplacental blood flow in the pregnant rabbit: a comparative study

    SciTech Connect

    Johnson, R.L.; Gilbert, M.; Meschia, G.; Battaglia, F.C.

    1985-03-01

    This study presents data on cardiac output distribution and uterine and placental blood flows in pregnant rabbits under chronic steady-state conditions. Ten litters and 67 fetuses were studied at 29 days of gestation, by means of radioactive microspheres. Five nonpregnant female animals were also studied for comparison. Mean cardiac outputs were 747.16 +/- 55.7 and 613.80 +/- 63.76 ml/min in the pregnant and nonpregnant states, respectively. In the pregnant animals, uterine and mammary blood flows were 6.7% +/- 0.7% and 5.1% +/- 0.5% of cardiac output, respectively. Within litters, the highest placental blood flows occurred at the ovarian and vaginal ends of the uterine horn. Placental blood flow per gram of fetus was 0.106 +/- 0.008 ml X min-1 X gm-1. A comparison with analogous data in the guinea pig and sheep demonstrates that toward the end of pregnancy placental blood flow per gram of fetus is approximately 2.5-times higher in sheep than in rabbits and guinea pigs. Expressed as a percentage of cardiac output, near-term uterine blood flow is significantly less in rabbits than in guinea pigs and sheep, whereas mammary blood flow is significantly higher. These interspecies differences are related to differences in placental structure, fetal/maternal mass ratio, and maturity at birth.

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

    PubMed

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

    2015-06-01

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

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

    NASA Technical Reports Server (NTRS)

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

    1976-01-01

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

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

    PubMed

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

    2011-10-01

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

  10. Estimation of cardiac output in patients with congestive heart failure by analysis of right ventricular pressure waveforms

    PubMed Central

    2011-01-01

    Background Cardiac output (CO) is an important determinant of the hemodynamic state in patients with congestive heart failure (CHF). We tested the hypothesis that CO can be estimated from the right ventricular (RV) pressure waveform in CHF patients using a pulse contour cardiac output algorithm that considers constant but patient specific RV outflow tract characteristic impedance. Method In 12 patients with CHF, breath-by-breath Fick CO and RV pressure waveforms were recorded utilizing an implantable hemodynamic monitor during a bicycle exercise protocol. These data were analyzed retrospectively to assess changes in characteristic impedance of the RV outflow tract during exercise. Four patients that were implanted with an implantable cardiac defibrillator (ICD) implementing the algorithm were studied prospectively. During a two staged sub-maximal bicycle exercise test conducted at 4 and 16 weeks of implant, COs measured by direct Fick technique and estimated by the ICD were recorded and compared. Results At rest the total pulmonary arterial resistance and the characteristic impedance were 675 345 and 48 18 dyn.s.cm-5, respectively. During sub-maximal exercise, the total pulmonary arterial resistance decreased (? 91 159 dyn.s.cm-5, p < 0.05) but the characteristic impedance was unaffected (? 3 9 dyn.s.cm-5, NS). The algorithm derived cardiac output estimates correlated with Fick CO (7.6 2.5 L/min, R2 = 0.92) with a limit of agreement of 1.7 L/min and tracked changes in Fick CO (R2 = 0.73). Conclusions The analysis of right ventricular pressure waveforms continuously recorded by an implantable hemodynamic monitor provides an estimate of CO and may prove useful in guiding treatment in patients with CHF. PMID:21569499

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

    NASA Technical Reports Server (NTRS)

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

    1998-01-01

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

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

    PubMed

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

    2013-01-01

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

  13. Cardiac MRI assessment of myocardial perfusion

    PubMed Central

    Hamirani, Yasmin S; Kramer, Christopher M

    2014-01-01

    Coronary artery disease is the most common cause of mortality and morbidity around the globe. Assessment of myocardial perfusion to diagnose ischemia is commonly performed in symptomatic patients prior to referral for cardiac catheterization. Among other noninvasive imaging modalities, cardiac MRI (CMR) is emerging as a highly sensitive and specific test for myocardial ischemia and infarction. Resting perfusion on CMR is used to evaluate for microvascular obstruction, which is shown to predict adverse left ventricular remodeling and cardiac events after acute myocardial infarction. This article summarizes the current understanding of CMR perfusion. PMID:24976472

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

    NASA Technical Reports Server (NTRS)

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

    1986-01-01

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

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

    PubMed Central

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

    2012-01-01

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

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

    PubMed Central

    Lee, Bo-Ae; Oh, Deuk-Ja

    2016-01-01

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

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

    PubMed

    Lee, Bo-Ae; Oh, Deuk-Ja

    2016-02-01

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

  18. Validation of an Ultrasound Cardiac Output Monitor as a Bedside Tool for Pediatric Patients.

    PubMed

    Beltramo, Fernando; Menteer, Jondavid; Razavi, Asma; Khemani, Robinder G; Szmuszkovicz, Jacqueline; Newth, Christopher J L; Ross, Patrick A

    2016-01-01

    The aim of our study was to determine the validity of cardiac output (CO) measurements taken with the ultrasonic cardiac output monitor (USCOM) by comparing to CO measured by pulmonary arterial catheter (PAC) thermodilution during cardiac catheterization. We enrolled thirty-one children (<18years) undergoing cardiac catheterization in this double-blinded, prospective, observational study. The median CO measured by USCOM was 4.37L/min (IQR 3.73, 5.60L/min) compared to 4.28L/min (IQR 3.52, 5.26L/min) by PAC thermodilution. The bias (mean difference) between the two methods was 0.2L/min, and the 95% limits of agreement were -1.2 to 1.6L/min. The mean percentage error of CO between USCOM and PAC thermodilution was 11%. When excluding a sole outlier, the bias between the two measures decreased to 0.1L/min (95% limits of agreement -0.6 to 0.9L/min), and the percentage error was reduced to 8%. The median SVRI measured by USCOM was 22.0 Wood Units (IQR 17.0, 26.8 Wood Units) compared to 22.1 Wood Units (IQR 17.6, 27.4 Wood Units) by PAC thermodilution. Bias (mean difference) between the two methods was -0.6 Wood Units, and the 95% limits of agreement were -8.2 to 6.9 Wood Units. We found that the estimation of CO and by extension SVRI with USCOM is reliable against pulmonary artery catheter thermodilution in children with normal cardiac anatomy. Given the noninvasive nature of USCOM, speed of measurement, and relative ease of use, it may be useful as a bedside tool for pediatric patients. PMID:26364291

  19. Mathematical basis for the measurement of absolute and fractional cardiac output with diffusible tracers by compartmental analysis methods.

    PubMed

    Charkes, N D

    1984-10-01

    Using compartmental analysis methods, a mathematical basis is given for the measurement of absolute and fractional cardiac output with diffusible tracers. Cardiac output is shown to be the product of the blood volume and the sum of the rate constants of tracer egress from blood, modified by a factor reflecting transcapillary diffusibility, the transfer fraction. The return of tracer to the blood and distant (intracellular) events are shown to play no role in the solution. Fractional cardiac output is the ratio of the rate constant of tracer egress from blood to an organ, divided by the sum of the egress constants from blood. Predominantly extracellular ions such as sodium or bromide are best suited for this technique, although theoretically any diffusible tracer whose compartmental model can be solved may be used. It is shown that fractional cardiac output is independent of the transfer fraction, and therefore can be measured accurately by tracers which are not freely diffusible. PMID:6240534

  20. Mathematical basis for the measurement of absolute and fractional cardiac output with diffusible tracers by compartmental analysis methods

    SciTech Connect

    Charkes, N.D.

    1984-10-01

    Using compartmental analysis methods, a mathematical basis is given for the measurement of absolute and fractional cardiac output with diffusible tracers. Cardiac output is shown to be the product of the blood volume and the sum of the rate constants of tracer egress from blood, modified by a factor reflecting transcapillary diffusibility, the transfer fraction. The return of tracer to the blood and distant (intracellular) events are shown to play no role in the solution. Fractional cardiac output is the ratio of the rate constant of tracer egress from blood to an organ, divided by the sum of the egress constants from blood. Predominantly extracellular ions such as sodium or bromide are best suited for this technique, although theoretically any diffusible tracer whose compartmental model can be solved may be used. It is shown that fractional cardiac output is independent of the transfer fraction, and therefore can be measured accurately by tracers which are not freely diffusible.

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

    PubMed Central

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

    2016-01-01

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

  2. Cardiac magnetic resonance assessment of takotsubo cardiomyopathy.

    PubMed

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

    2016-01-01

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

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

    PubMed Central

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

    2014-01-01

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

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

    PubMed

    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 beatmin(-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 Lmin(-1) per Lmin(-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 Lmin(-1) per Lmin(-1). Mean arterial blood pressure and pulse pressure from rest to exercise rose similarly in both groups. We conclude that 40% of POTS adolescents demonstrate a hyperkinetic circulation during exercise. We attribute this to failure of normal regional vasoconstriction during exercise, such that patients must increase flow through an inappropriately vasodilated systemic circulation to maintain perfusion pressure. PMID:25168872

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed

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

    2016-02-01

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

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

    PubMed Central

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

    2012-01-01

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

  8. Sensitivity of Outcome Assessment in Cardiac Rehabilitation.

    ERIC Educational Resources Information Center

    Denollet, Johan

    1993-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2005-02-01

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

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

    PubMed

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

    2016-03-01

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

  11. Automated non-invasive measurement of cardiac output: comparison of electrical bioimpedance and carbon dioxide rebreathing techniques.

    PubMed Central

    Smith, S A; Russell, A E; West, M J; Chalmers, J

    1988-01-01

    Two commercial automated, non-invasive systems for estimation of cardiac output were evaluated. Values of cardiac output obtained by electrical bioimpedance cardiography (BoMed NCCOM3 machine) were compared with values derived from an indirect Fick technique that uses carbon dioxide rebreathing (Gould 9000 IV system) during 103 simultaneous measurements made at rest in 19 randomly selected subjects and on exercise in 11 subjects. Cardiac output values obtained with impedance cardiography were significantly correlated with those measured by the indirect Fick method, although there was a wide scatter with over 73% of the readings lying outside the limits defined by the line of identity +/- 20%. This correlation was greatly reduced when stroke volume index was used instead of cardiac output. Indirect Fick results were linearly related to oxygen uptake both at rest and on exercise, while impedance cardiography results did not correlate with oxygen uptake. Impedance cardiography gave consistently lower results for cardiac output than indirect Fick at all levels of exercise. Both machines were easy to use and produced acceptable mean (SE) coefficients of variation (BoMed NCCOM3 7.7 (1.0)%, Gould 9000 IV 10.6 (1.4)%). Further validation is required before either of these machines can be recommended as an alternative to invasive monitoring in clinical practice. PMID:3128316

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

    PubMed Central

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

    2013-01-01

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

  13. Improved noninvasive method for measurement of cardiac output and evaluation of left-sided cardiac valve incompetence

    SciTech Connect

    Kelbaek, H.

    1989-05-01

    A time-saving method was developed to label red blood cells in vitro with /sup 99m/Tc while avoiding centrifugation. After tin incubation, extracellular tin was oxidized by sodium hypochlorite, and EDTA was added for stabilizing the complex prior to /sup 99m/Tc incubation. Labeling yields were 95%, and in vivo decay showed a high stability with a mean biologic half-life of eleven hours. The first-passage radionuclide technique for determination of cardiac output using the above-mentioned tracer was evaluated by using the left ventricle as area-of-interest with individual background correction after complete mixing of the tracer. This technique showed a high level of agreement with invasive methods. By combining this method for measurement of the forward stroke volume with the multigated equilibrium principle for determination of the total left ventricular stroke volume using similar background corrections, an exact evaluation of regurgitation fractions was obtained. In patients with aortic and mitral valve disease the noninvasive radionuclide technique gave similar but probably more accurate results as compared with contrast aortography and ventriculography. The radionuclide technique may be suitable for monitoring and selecting patients for surgical treatment.

  14. Simulation Evaluation of Quantitative Myocardial Perfusion Assessment from Cardiac CT.

    PubMed

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

    2014-03-19

    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 blood flow estimation. In conclusion, quantitative model-based dynamic cardiac CT perfusion assessment is capable of accurately estimating MBF across a range of cardiac outputs and tissue perfusion states, outperforms comparable static perfusion estimates, and is relatively robust to noise and temporal subsampling. PMID:25395812

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

    NASA Astrophysics Data System (ADS)

    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 blood flow estimation. In conclusion, quantitative model-based dynamic cardiac CT perfusion assessment is capable of accurately estimating MBF across a range of cardiac outputs and tissue perfusion states, outperforms comparable static perfusion estimates, and is relatively robust to noise and temporal subsampling.

  16. Noninvasive photoacoustic measurement of the composite indicator dilution curve for cardiac output estimation

    PubMed Central

    Kang, DongYel; Huang, Qiaojian; Li, Youzhi

    2015-01-01

    Recently, the measurement of indicator dilution curves using a photoacoustic (PA) technology was reported, which showed promising results on the noninvasive estimation of cardiac output (CO) that is an important hemodynamic parameter useful in various clinical situations. However, in clinical practice, measuring PA indicator dilution curves from an arterial blood vessel requires an ultrasound transducer array capable of focusing on the targeted artery. This causes several challenges on the clinical translation of the PA indicator dilution method, such as high sensor cost and complexity. In this paper, we theoretically derived that a composite PA indicator dilution curve simultaneously measured from both arterial and venous blood vessels can be used to estimate CO correctly. The ex-vivo and in-vivo experimental results with a flat ultrasound transducer verified the developed theory. We believe this new concept would overcome the main challenges on the clinical translation of the noninvasive PA indicator dilution technology. PMID:25780743

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

    SciTech Connect

    Williams, L.R.

    1994-09-01

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

  18. Design and assessment of cardiac SPECT systems

    NASA Astrophysics Data System (ADS)

    Lee, Chih-Jie

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

  19. Rowing increases stroke volume and cardiac output to a greater extent than cycling.

    PubMed

    Horn, P; Ostadal, P; Ostadal, B

    2015-01-01

    Exercise stimulates increases in heart rate (HR), stroke volume (SV) and cardiac output (CO). These adaptive mechanisms are strongly dependent on the type of exercise. Both rowing and cycling are widely used for physical training worldwide; however, evidence regarding the differences in major hemodynamic parameters during rowing and cycling remains insufficient. Ten healthy male volunteers were randomly assigned to perform either a rowing or cycling exercise. After 20 min rest, the group who had rowed first performed the cycling exercise and vice versa. Exercise was performed at a power-to-weight ratio of 2 W/kg for 2 min. HR, SV, CO and blood pressure (BP) were measured noninvasively using pulse-wave analysis at baseline and immediately after each exercise. HR, SV and CO were significantly higher after exercise than at rest. Whereas HR was comparable between rowing and cycling, SV and CO were significantly higher after rowing than after cycling. BP was comparable among all three measurements. Rowing increased SV and CO to a greater extent than cycling, whereas HR and BP were not influenced by the type of exercise. Our data suggest that rowing leads to more extensive stimulation of cardiac contractility and/or decreases in peripheral vascular resistance compared with cycling. PMID:25317691

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

    PubMed Central

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

    2012-01-01

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

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

    NASA Technical Reports Server (NTRS)

    1980-01-01

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

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

    PubMed Central

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

    2007-01-01

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

  3. Determination of cardiac output by an angle and diameter independent dual beam Doppler technique in critically ill infants.

    PubMed Central

    Wippermann, C F; Schranz, D; Huth, R; Zepp, F; Oelert, H; Jngst, B K

    1992-01-01

    OBJECTIVE--To compare cardiac output measurements in critically ill infants by the dual beam Doppler and thermodilution techniques. DESIGN--Prospective direct comparison of the two techniques. For statistical evaluation one randomly assigned paired measurement of every patient was used. SETTING--Paediatric intensive care unit in a university hospital. PATIENTS--18 infants after open heart surgery aged 4-25 months (weight 4-10 kg). INTERVENTIONS--Cardiac output measurements by dual beam Doppler and thermodilution techniques were performed within 10 minutes of each other and without knowledge of the results of the other methods. Multiple measurements were performed on some patients with a pharmacological or electrophysiological intervention or with a minimum of six hours between each pair of measurements. MEASUREMENTS AND MAIN RESULTS--Three patients were excluded because of an inadequate Doppler signal or a significant residual shunt. Cardiac output measurements ranged from 0.4 to 2.2 l/min for the thermodilution technique and from 0.5 to 2.1 l/min for the dual beam Doppler technique. Agreement between both methods was acceptable. The mean difference between the two methods was 0.026 l/min with two standard deviations ranging from -0.20 to 0.26 l/min. CONCLUSION--The dual beam Doppler technique was shown to have promise for the non-invasive determination of cardiac output in critically ill infants. PMID:1540440

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

    PubMed

    Hapfelmeier, Alexander; Cecconi, Maurizio; Saugel, Bernd

    2016-04-01

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

  5. Acoustic output of multi-line transmit beamforming for fast cardiac imaging: a simulation study.

    PubMed

    Santos, Pedro; Tong, Ling; Ortega, Alejandra; Lvstakken, Lasse; Samset, Eigil; D'hooge, Jan

    2015-07-01

    Achieving higher frame rates in cardiac ultrasound could unveil short-lived myocardial events and lead to new insights on cardiac function. Multi-line transmit (MLT) beamforming (i.e., simultaneously transmitting multiple focused beams) is a potential approach to achieve this. However, two challenges come with it: first, it leads to cross-talk between the MLT beams, appearing as imaging artifacts, and second, it presents acoustic summation in the near field, where multiple MLT beams overlap. Although several studies have focused on the former, no studies have looked into the implications of the latter on acoustic safety. In this paper, the acoustic field of 4-MLT was simulated and compared with single-line transmit (SLT). The findings suggest that standard MLT does present potential concerns. Compared with SLT, it shows a 2-fold increase in mechanical index (MI) (from 1.0 to 2.3), a 6-fold increase in spatial-peak pulse-average intensity (I(sppa)) (from 99 to 576 W?cm(-2)) and a 12-fold increase in spatial-peak temporalaverage intensity (I(spta)) (from 119 to 1407 mW?cm(-2)). Subsequently, modifications of the transmit pulse and delay line of MLT were studied. These modifications allowed for a change in the spatio-temporal distribution of the acoustic output, thereby significantly decreasing the safety indices (MI = 1.2, I(sppa) = 92 W?cm(-2) and I(spta) = 366 mW?cm(-2)). Accordingly, they help mitigate the concerns around MLT, reducing potential tradeoffs between acoustic safety and image quality. PMID:26168178

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

    NASA Technical Reports Server (NTRS)

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

    1993-01-01

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

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed

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

    2016-01-01

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

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

    PubMed Central

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

    2016-01-01

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

  10. Cardiac Output and Cerebral Blood Flow: The Integrated Regulation of Brain Perfusion in Adult Humans.

    PubMed

    Meng, Lingzhong; Hou, Wugang; Chui, Jason; Han, Ruquan; Gelb, Adrian W

    2015-11-01

    Cerebral blood flow (CBF) is rigorously regulated by various powerful mechanisms to safeguard the match between cerebral metabolic demand and supply. The question of how a change in cardiac output (CO) affects CBF is fundamental, because CBF is dependent on constantly receiving a significant proportion of CO. The authors reviewed the studies that investigated the association between CO and CBF in healthy volunteers and patients with chronic heart failure. The overall evidence shows that an alteration in CO, either acutely or chronically, leads to a change in CBF that is independent of other CBF-regulating parameters including blood pressure and carbon dioxide. However, studies on the association between CO and CBF in patients with varying neurologic, medical, and surgical conditions were confounded by methodologic limitations. Given that CBF regulation is multifactorial but the various processes must exert their effects on the cerebral circulation simultaneously, the authors propose a conceptual framework that integrates the various CBF-regulating processes at the level of cerebral arteries/arterioles while still maintaining autoregulation. The clinical implications pertinent to the effect of CO on CBF are discussed. Outcome research relating to the management of CO and CBF in high-risk patients or during high-risk surgeries is needed. PMID:26402848

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

    NASA Technical Reports Server (NTRS)

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

    2002-01-01

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

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed

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

    2013-12-01

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

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

    PubMed

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

    1989-09-01

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

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

    SciTech Connect

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

    1984-01-01

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

  16. Assessment of Electrosurgery Burns in Cardiac Surgery

    PubMed Central

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

    2015-01-01

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

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

    PubMed Central

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

    2016-01-01

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

  18. Monitoring non-invasive cardiac output and stroke volume during experimental human hypovolaemia and resuscitation

    PubMed Central

    Reisner, A. T.; Xu, D.; Ryan, K. L.; Convertino, V. A.; Rickards, C. A.; Mukkamala, R.

    2011-01-01

    Background Multiple methods for non-invasive measurement of cardiac output (CO) and stroke volume (SV) exist. Their comparative capabilities are not clearly established. Methods Healthy human subjects (n=21) underwent central hypovolaemia through progressive lower body negative pressure (LBNP) until the onset of presyncope, followed by termination of LBNP, to simulate complete resuscitation. Measurement methods were electrical bioimpedance (EBI) of the thorax and three measurements of CO and SV derived from the arterial blood pressure (ABP) waveform: the Modelflow (MF) method, the long-time interval (LTI) method, and pulse pressure (PP). We computed areas under receiver-operating characteristic curves (ROC AUCs) for the investigational metrics, to determine how well they discriminated between every combination of LBNP levels. Results LTI and EBI yielded similar reductions in SV during progressive hypovolaemia and resuscitation (correlation coefficient 0.83) with ROC AUCs for distinguishing major LBNP (?60 mm Hg) vs resuscitation (0 mm Hg) of 0.98 and 0.99, respectively. MF yielded very similar reductions and ROC AUCs during progressive hypovolaemia, but after resuscitation, MF-CO did not return to baseline, yielding lower ROC AUCs (?ROC AUC range, ?0.18 to ?0.26, P<0.01). PP declined during hypovolaemia but tended to be an inferior indicator of specific LBNP levels, and PP did not recover during resuscitation, yielding lower ROC curves (P<0.01). Conclusions LTI, EBI, and MF were able to track progressive hypovolaemia. PP decreased during hypovolaemia but its magnitude of reduction underestimated reductions in SV. PP and MF were inferior for the identification of resuscitation. PMID:21051492

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

    PubMed Central

    Yoshida, T; Whipp, B J

    1994-01-01

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

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

    SciTech Connect

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

    1986-03-01

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

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

    PubMed Central

    Neal, Maxwell Lewis; Bassingthwaighte, James B.

    2010-01-01

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

  2. Measurement of cardiac output during exercise by open-circuit acetylene uptake.

    PubMed

    Barker, R C; Hopkins, S R; Kellogg, N; Olfert, I M; Brutsaert, T D; Gavin, T P; Entin, P L; Rice, A J; Wagner, P D

    1999-10-01

    Noninvasive measurement of cardiac output (QT) is problematic during heavy exercise. We report a new approach that avoids unpleasant rebreathing and resultant changes in alveolar PO(2) or PCO(2) by measuring short-term acetylene (C(2)H(2)) uptake by an open-circuit technique, with application of mass balance for the calculation of QT. The method assumes that alveolar and arterial C(2)H(2) pressures are the same, and we account for C(2)H(2) recirculation by extrapolating end-tidal C(2)H(2) back to breath 1 of the maneuver. We correct for incomplete gas mixing by using He in the inspired mixture. The maneuver involves switching the subject to air containing trace amounts of C(2)H(2) and He; ventilation and pressures of He, C(2)H(2), and CO(2) are measured continuously (the latter by mass spectrometer) for 20-25 breaths. Data from three subjects for whom multiple Fick O(2) measurements of QT were available showed that measurement of QT by the Fick method and by the C(2)H(2) technique was statistically similar from rest to 90% of maximal O(2) consumption (VO(2 max)). Data from 12 active women and 12 elite male athletes at rest and 90% of VO(2 max) fell on a single linear relationship, with O(2) consumption (VO(2)) predicting QT values of 9.13, 15.9, 22.6, and 29.4 l/min at VO(2) of 1, 2, 3, and 4 l/min. Mixed venous PO(2) predicted from C(2)H(2)-determined QT, measured VO(2), and arterial O(2) concentration was approximately 20-25 Torr at 90% of VO(2 max) during air breathing and 10-15 Torr during 13% O(2) breathing. This modification of previous gas uptake methods, to avoid rebreathing, produces reasonable data from rest to heavy exercise in normal subjects. PMID:10517785

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

    PubMed Central

    Sabzi, Feridoun; Faraji, Reza

    2015-01-01

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

  4. Non-Invasive Determination of Cardiac Output in Pre-Capillary Pulmonary Hypertension

    PubMed Central

    Lador, Frdric; Herv, Philippe; Bringard, Aurlien; Gnther, Sven; Garcia, Gilles; Savale, Laurent; Ferretti, Guido; Soccal, Paola M.; Chemla, Denis; Humbert, Marc; Simonneau, Grald; Sitbon, Olivier

    2015-01-01

    Background Cardiac output (CO) is a major diagnostic and prognostic factor in pre-capillary pulmonary hypertension (PH). Reference methods for CO determination, like thermodilution (TD), require invasive procedures and allow only steady-state measurements. The Modelflow (MF) method is an appealing technique for this purpose as it allows non-invasive and beat-by-beat determination of CO. Methods We aimed to compare CO values obtained simultaneously from non-invasive pulse wave analysis by MF (COMF) and by TD (COTD) to determine its precision and accuracy in pre-capillary PH. The study was performed on 50 patients with pulmonary arterial hypertension (PAH) or chronic thrombo-embolic PH (CTEPH). CO was determined at rest in all patients (n = 50) and during nitric oxide vasoreactivity test, fluid challenge or exercise (n = 48). Results Baseline COMF and COTD were 6.18 1.95 and 5.46 1.95 Lmin-1, respectively. Accuracy and precision were 0.72 and 1.04 Lmin-1, respectively. Limits of agreement (LoA) ranged from -1.32 to 2.76 Lmin-1. Percentage error (PE) was 35.7%. Overall sensitivity and specificity of COMF for directional change were 95.2% and 82.4%, (n = 48) and 93.3% and 100% for directional changes during exercise (n = 16), respectively. After application of a correction factor (1.17 0.25), neither proportional nor fixed bias was found for subsequent CO determination (n = 48). Accuracy was -0.03 Lmin?1 and precision 0.61 Lmin?1. LoA ranged from -1.23 to 1.17 Lmin?1 and PE was 19.8%. Conclusions After correction against a reference method, MF is precise and accurate enough to determine absolute values and beat-by-beat relative changes of CO in pre-capillary PH. PMID:26226280

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

    PubMed

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

    2012-05-01

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

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

    PubMed Central

    Tuttle, Ann; Shore, Scott; Stone, Terry

    2009-01-01

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

  7. Diesel Exhaust Inhalation Increases Cardiac Output, Bradyarrhythmias, and Parasympathetic Tone in Aged Heart FailureProne Rats

    PubMed Central

    Farraj, Aimen K.

    2013-01-01

    Acute air pollutant inhalation is linked to adverse cardiac events and death, and hospitalizations for heart failure. Diesel engine exhaust (DE) is a major air pollutant suspected to exacerbate preexisting cardiac conditions, in part, through autonomic and electrophysiologic disturbance of normal cardiac function. To explore this putative mechanism, we examined cardiophysiologic responses to DE inhalation in a model of aged heart failureprone rats without signs or symptoms of overt heart failure. We hypothesized that acute DE exposure would alter heart rhythm, cardiac electrophysiology, and ventricular performance and dimensions consistent with autonomic imbalance while increasing biochemical markers of toxicity. Spontaneously hypertensive heart failure rats (16 months) were exposed once to whole DE (4h, target PM2.5 concentration: 500 g/m3) or filtered air. DE increased multiple heart rate variability (HRV) parameters during exposure. In the 4h after exposure, DE increased cardiac output, left ventricular volume (end diastolic and systolic), stroke volume, HRV, and atrioventricular block arrhythmias while increasing electrocardiographic measures of ventricular repolarization (i.e., ST and T amplitudes, ST area, T-peak to T-end duration). DE did not affect heart rate relative to air. Changes in HRV positively correlated with postexposure changes in bradyarrhythmia frequency, repolarization, and echocardiographic parameters. At 24h postexposure, DE-exposed rats had increased serum C-reactive protein and pulmonary eosinophils. This study demonstrates that cardiac effects of DE inhalation are likely to occur through changes in autonomic balance associated with modulation of cardiac electrophysiology and mechanical function and may offer insights into the adverse health effects of traffic-related air pollutants. PMID:23047911

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

    PubMed

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

    2016-02-01

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

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

    PubMed Central

    Phillips, Robert A.; Hood, Sally G.; Jacobson, Beverley M.; West, Malcolm J.; Wan, Li; May, Clive N.

    2012-01-01

    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, (n = 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. PMID:22649718

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

    NASA Technical Reports Server (NTRS)

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

    1992-01-01

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

  11. Cardiac output and oxygen release during very high-intensity exercise performed until exhaustion.

    PubMed

    Richard, Ruddy; Lonsdorfer-Wolf, Evelyne; Dufour, Stphane; Doutreleau, Stphane; Oswald-Mammosser, Monique; Billat, Vronique L; Lonsdorfer, Jean

    2004-10-01

    Our objectives were firstly, to study the patterns of the cardiac output (Q(.)) and the arteriovenous oxygen difference [(a-nu(-))O(2)] responses to oxygen uptake (V(.)O(2)) during constant workload exercise (CWE) performed above the respiratory compensation point (RCP), and secondly, to establish the relationships between their kinetics and the time to exhaustion. Nine subjects performed two tests: a maximal incremental exercise test (IET) to determine the maximal V(.)O(2) (V(.)O(2)peak), and a CWE test to exhaustion, performed at p Delta50 (intermediate power between RCP and V(.)O(2)peak). During CWE, V(.)O(2) was measured breath-by-breath, Q(.) was measured beat-by-beat with an impedance device, and blood lactate (LA) was sampled each minute. To calculate ( a-nu(-)O(2), the values of V(.)O(2) and Q(.) were synchronised over 10 s intervals. A fitting method was used to describe the V(.)O(2), Q(.) and ( a-nu(-))O(2) kinetics. The ( a-nu(-)O(2) difference followed a rapid monoexponential function, whereas both V(.)O(2) and Q(.) were best fitted by a single exponential plus linear increase: the time constant (tau) V(.)O(2) [57 (20 s)] was similar to tau ( a-nu(-)O(2), whereas tau for Q(.) was significantly higher [89 (34) s, P <0.05] (values expressed as the mean and standard error). LA started to increase after 2 min CWE then increased rapidly, reaching a similar maximal value as that seen during the IET. During CWE, the rapid component of V(.)O(2) uptake was determined by a rapid and maximal ( a-nu(-)O(2) extraction coupled with a two-fold longer Q(.) increase. It is likely that lactic acidosis markedly increased oxygen availability, which when associated with the slow linear increase of Q(.), may account for the V(.)O(2) slow component. Time to exhaustion was larger in individuals with shorter time delay for ( a-nu(-)O(2) and a greater tau for Q(.). PMID:15278352

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

    PubMed

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

    2015-01-01

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

  13. GLUCAGON LIKE PEPTIDE-1(736) BUT NOT (936) AUGMENTS CARDIAC OUTPUT DURING MYOCARDIAL ISCHEMIA VIA AFRANK-STARLING MECHANISM

    PubMed Central

    Goodwill, Adam G.; Tune, Johnathan D.; Noblet, Jillian N.; Conteh, Abass M.; Sassoon, Daniel; Casalini, Eli D.; Mather, Kieren J.

    2014-01-01

    This study examined the cardiovascular effects of GLP-1 (736) or (936) on myocardial oxygen consumption, function and systemic hemodynamics in vivo during normal perfusion and during acute, regional myocardial ischemia. Lean Ossabaw swine received systemic infusions of saline vehicle or GLP-1 (736 or 936) at 1.5, 3.0, and 10.0 pmol/kg/min in sequence for 30 min at each dose, followed by ligation of the left circumflex artery during continued infusion at 10.0 pmol/kg/min. Systemic GLP-1 (936) had no effect on coronary flow, blood pressure, heart rate or indices of cardiac function before or during regional myocardial ischemia. Systemic GLP-1 (736) exerted no cardiometabolic or hemodynamic effects prior to ischemia. During ischemia, GLP-1 (736) increased cardiac output by approximately 2 L/min relative to vehicle-controls (p=0.003). This response was not diminished by treatment with the non-depolarizing ganglionic blocker hexamethonium. Left ventricular pressure-volume loops measured during steady state conditions with graded occlusion of the inferior vena cava to assess load-independent contractility revealed that GLP-1 (736) produced marked increases in end diastolic volume (74 1 to 92 5 mL; p=0.03) and volume axis intercept (8 2 to 26 8; p=0.05), without any change in the slope of the end systolic pressure volume relationship vs. vehicle during regional ischemia. GLP-1 (936) produced no changes in any of these parameters compared to vehicle. These findings indicate that short-term systemic treatment with GLP-1 (736) but not GLP-1 (936) significantly augments cardiac output during regional myocardial ischemia, via increases in ventricular preload without changes in cardiac inotropy. PMID:25005062

  14. Trending ability and limitations of transpulmonary thermodilution and pulse contour cardiac output measurement in cats as a model for pediatric patients.

    PubMed

    Kutter, Annette P N; Bektas, Rima N; Hofer, Christoph K; Larenza Menzies, M Paula; Bettschart-Wolfensberger, Regula

    2015-06-01

    The present study evaluated transpulmonary thermodilution (TPTD) and pulse contour cardiac output (PCCO) both measured by the PiCCO Plus monitor (Pulsion Medical Systems, Munich, Germany) against pulmonary artery thermodilution (PATD) in cats as a hemodynamic model for small children. A wide range of cardiac outputs (CO) was simultaneously measured. Accuracy and trending abilities were critically evaluated. Three cats were studied under isoflurane anesthesia and 160 CO measurements were performed with 3 mL ice-cold 5 % dextrose with PATD and TPTD. The results were compared with the PCCO measurement before the bolus measurement. Cardiac output was manipulated from 32 to 224 mL/kg/min by dobutamine, dopamine, phenylephrine, medetomidine and increased concentrations of isoflurane. Bland-Altman analysis, concordance and polar plot analysis were performed to assess accuracy and trending ability. TPTD was measuring constantly higher than PATD with a mean bias of 73 mL/kg/min and limits of agreement of 34-112 mL/kg/min, a concordance rate of 94 % and a mean polar angle of -5 with radial limits of agreement (RLOA) of 33. Concordance rate of the PCCO versus PATD was 82 % with a mean polar angle of -10 and RLOA of 46 and versus TPTD 90 % with a mean polar angle of -6 and RLOA of 46. Both tested methods constantly overestimated simultaneous PATD measurements. The small size, low flows and the relative short catheter not reaching the abdominal aorta may explain that. However TPTD tracked changes accurately opposed to a poor trending ability of the PCCO measurement. PMID:25228023

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

    PubMed

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

    2016-01-01

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

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

    NASA Astrophysics Data System (ADS)

    Soukup, Ladislav; Vondra, Vlastimil; Vi?or, Ivo; Jurk, Pavel; Halmek, Josef

    2013-04-01

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

  17. Blunted frequency-dependent upregulation of cardiac output is related to impaired relaxation in diastolic heart failure

    PubMed Central

    Wachter, Rolf; Schmidt-Schweda, Stephan; Westermann, Dirk; Post, Heiner; Edelmann, Frank; Kasner, Mario; Lers, Claus; Steendijk, Paul; Hasenfu, Gerd; Tschpe, Carsten; Pieske, Burkert

    2009-01-01

    Aims We tested the hypothesis that, in heart failure with normal ejection fraction (HFNEF), diastolic dysfunction is accentuated at increasing heart rates, and this contributes to impaired frequency-dependent augmentation of cardiac output. Methods and results In 17 patients with HFNEF (median age 69 years, 13 female) and seven age-matched control patients, systolic and diastolic function was analysed by pressurevolume loops at baseline heart rate and during atrial pacing to 100 and 120 min?1. At baseline, relaxation was prolonged and end-diastolic left ventricular stiffness was higher in HFNEF, whereas all parameters of systolic function were not different from control patients. This resulted in smaller end-diastolic volumes, higher end-diastolic pressure, and a lower stroke volume and cardiac index in HFNEF vs. control patients. During pacing, frequency-dependent upregulation of contractility indices (+dP/dtmax and Ees) occurred similarly in HFNEF and control patients, but frequency-dependent acceleration of relaxation (dP/dtmin) was blunted in HFNEF. In HFNEF, end-diastolic volume and stroke volume decreased with higher heart rates while both remained unchanged in control patients. Conclusion In HFNEF, frequency-dependent upregulation of cardiac output is blunted. This results from progressive volume unloading of the left ventricle due to limited relaxation reserve in combination with increased LV passive stiffness, despite preserved forcefrequency relation. PMID:19720638

  18. Scintigraphic assessment of heterotopic cardiac transplants

    SciTech Connect

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

    1981-10-01

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

  19. Scintigraphic assessment of heterotopic cardiac transplants

    SciTech Connect

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

    1981-01-01

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

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

    PubMed Central

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

    2014-01-01

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

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

    NASA Technical Reports Server (NTRS)

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

    2011-01-01

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

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

    PubMed

    Wauters, Aurlien; Vicenzi, Marco; De Becker, Benjamin; Riga, Jean-Philippe; Esmaeilzadeh, Fatemeh; Faoro, Vitalie; Vachiry, Jean-Luc; van de Borne, Philippe; Argacha, Jean-Franois

    2015-12-15

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

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

    PubMed

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

    2016-02-01

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

  4. Preoperative cardiac assessment in patients undergoing major vascular surgery.

    PubMed

    Troisi, Nicola; Pulli, Raffaele; Dorigo, Walter; Lo Sapio, Patrizia; Pratesi, Carlo

    2011-08-01

    The aim of this study was to evaluate the effectiveness of a preoperative standardized cardiac assessment in patients undergoing major vascular surgery. From January 2005 to December 2006, 1446 elective interventions for major vascular diseases (carotid stenosis, CS; abdominal aortic aneurysm, AAA; peripheral arterial obstructive disease, PAOD) were performed; 1090 out of these patients underwent preoperative diagnostic assessment on an outpatient basis. Thirty-day results in terms of cardiac mortality and morbidity rates were recorded. Patients suffered from a CS in 578 cases (53%), an AAA in 303 cases (27.8%) and a PAOD in 209 cases (19.2%). Four hundred thirty-two patients (39.6%) underwent further evaluation of cardiac functional capacity with non-invasive stress testing. Sixteen patients were successfully treated prior to vascular surgery. Thirty-day cardiac mortality and morbidity rates were 0.2% and 3.9%, respectively. A positive preoperative non-invasive stress testing did not affect 30-day cardiac outcomes. In conclusion, the use of an accurate preoperative cardiac assessment allowed us to obtain satisfactory perioperative results in patients undergoing major vascular surgery. Routine preoperative evaluation with non-invasive stress testing did not seem to improve perioperative cardiac results. PMID:21742935

  5. Numerical observer for cardiac motion assessment using machine learning

    NASA Astrophysics Data System (ADS)

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

    2011-03-01

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

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

    PubMed

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

    2015-11-01

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

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

    PubMed Central

    2012-01-01

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

  8. Optimal dose of landiolol for preventing abrupt changes in both cardiac output and middle cerebral artery flow velocity after electroconvulsive therapy.

    PubMed

    Kadoi, Yuji; Saito, Shigeru

    2014-09-01

    The purpose of this study was to examine the dose-dependent effects of landiolol on systemic hemodynamics, cardiac output, and cerebral artery blood flow. Eight patients undergoing electroconvulsive therapy (ECT) received 1 of the 3 drugs/doses (saline, 0.125 mg/kg of landiolol, 0.25 mg/kg of landiolol), in turn, for 3 ECT sessions, immediately after the administration of succinylcholine. In the case of 0.25 mg/kg of landiolol, heart rate, mean arterial pressure, and cardiac output remained unchanged throughout the study period.We believe that 0.25 mg/kg of landiolol may be suitable for preventing the increase in systemic hemodynamics, including cardiac output after ECT. PMID:24755725

  9. A hand-held device to measure oxygen uptake: performance characteristics, patient selection and the propagation of its measurement error into fick cardiac output determinations.

    PubMed

    Shepherd, Albert P; Terpolilli, Beth M; Steinke, John M

    2007-03-01

    Measured oxygen consumption rates (VO2) are being used less frequently for direct Fick cardiac output determinations during cardiac catheterization because the instruments that measure VO2 are usually cumbersome, expensive and difficult to use. A small, inexpensive VO2 device recently became available. Therefore, the aims of this report are: (1) to delineate the advantages and limitations that would affect its use during cardiac catheterization; (2) to define the patient population in which its use would be safe and effective; and (3) to estimate the accuracy of cardiac output determinations based on its VO2 measurements. The MedGem is a fist-size device that measures VO2 as a patient breathes through it using either a facemask or mouthpiece. We evaluated it by measuring the external deadspace it imposes on the patient, by measuring the time required for each measurement, by determining its precision from repeated measurements on healthy volunteers and animals, and by developing a statistical model that calculates cardiac output error as a function of the random errors in the measurements of arterial and venous oxygen concentrations and VO2. Our experience indicates the MedGem is easy to operate and can be used for a wide spectrum of patients at rest including children with the ventilatory capacity to compensate for the added deadspace. Cardiac output determinations made with the MedGem's measurements of oxygen uptake are clinically acceptable if the oximeter used to measure oxygen in arterial and mixed venous blood is also sufficiently accurate. Our statistical model illustrates strategies to minimize cardiac output error. PMID:17341778

  10. Quality assessment of cardiac surgery in Britain.

    PubMed

    Treasure, T; Bridgewater, B; Gallivan, S

    2009-10-01

    Data are available for every Cardiac Surgery unit in Britain and in 70 % are identifiable by surgeon. The data are linked to registration of deaths so survival for a range of operations, and associated patient or procedure related factors, can be evaluated. The choice of statistical triggers (outside 99.99 % confidence intervals) and the time frames of reported data (averaged over three years) (See P.285/353 of the report http://www.scts.org/documents/PDF/5thBlueBook2003.pdf) reduces its value as an early warning system but the rigour of data collecting systems and the level of scrutiny required probably ensure that poor performance will be detected. PMID:19834854

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

    PubMed

    Lobodzinski, S Suave

    2013-01-01

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

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

    SciTech Connect

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

    1991-04-01

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

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

    NASA Technical Reports Server (NTRS)

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

    1971-01-01

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

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

    PubMed

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

    2015-08-01

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

  15. Evaluation of a morphological filter in mean cardiac output determination: application to left ventricular assist devices.

    PubMed

    Stevens, Michael Charles; Bradley, Andrew P; Wilson, Stephen J; Mason, David Glen

    2013-08-01

    A morphological filter (MF) is presented for the determination of beat-to-beat mean rotary left ventricular assist device (LVAD) flow rate, measured using an implanted flow probe. The performance of this non-linear filter was assessed using LVAD flow rate (QLVAD) data sets obtained from in silico and in vivo sources. The MF was compared with a third-order Butterworth filter (BWF) and a 10-s moving average filter (MAF). Performance was assessed by calculating the response time and steady state error across a range of heart rates and levels of noise. The response time of the MF was 3.5 times faster than the MAF, 0.5s slower than the BWF, and had a steady state error of 2.61%. It completely removed pulsatile signal components caused by residual ventricular function, and tracked sharp transient changes in QLVAD better than the BWF. The use of a two-stage MF improved the noise immunity compared to the single-stage MF. This study showed that the good performance characteristics of the non-linear MF make it a more suitable candidate for embedded real-time processing of QLVAD than linear filters. PMID:23526415

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

    PubMed

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

    2011-11-01

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

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

    EPA Science Inventory

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

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

    PubMed Central

    2013-01-01

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

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

    PubMed Central

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

    2011-01-01

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

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

    PubMed Central

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

    2012-01-01

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

  1. Effect of cardiac output on pulmonary gas exchange: role of diffusion limitation with VA/Q mismatch.

    PubMed

    Vidal Melo, M F

    1998-07-01

    We studied the effect of the interaction between diffusion limitation and alveolar ventilation to perfusion ratio (VA/Q) mismatch in the relation between blood gas partial pressures and cardiac output (Q). The analysis was based on a mathematical model of gas exchange involving two exchanging compartments and a right to left shunt. A system of equations describing alveolar-arterial mass conservation for O2, CO2 and N2 and Bohr integration for O2 and CO2 was interactively solved to find sets of alveolar and blood gas partial pressures fitting input data. Simulations used values compatible with patients in respiratory failure and neonate piglets. Association of (VA/Q) mismatch and diffusion impairment limited the increase of PaO2 with Q. A maximum in the PaO2 vs. Q curve can be attained, further Q increases lead to reductions in PaO2. The effect was accentuated by increasing (VA/Q) and diffusion to perfusion heterogeneity. Combination of (VA/Q) mismatch and diffusion limitation was synergistic leading to greater reductions in PaO2 than expected from simple addition of their independent influences. The findings are compatible with experimental data. PMID:9776547

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

    SciTech Connect

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

    1986-03-05

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

  3. Assessment of respiratory output in mechanically ventilated patients.

    PubMed

    Laghi, Franco

    2005-06-01

    Mechanically ventilated patients are subject to few pathophysiologic disturbances that have such intuitive importance as abnormal function of the respiratory output. Abnormal function of the respiratory output plays a fundamental role in all aspects of mechanical ventilation: in determining which patients require mechanical ventilation, in determining the interaction between a patient and the ventilator, and in determining when a patient can tolerate discontinuation of mechanical ventilation. Monitoring indexes such as the rate of rise in electrical activity of the diaphragm, Po.1, (dP/dt)max, and Pmus, has provided insight into the performance of the respiratory centers in critically ill patients, but these methods require considerable refinement. A large body of research on measurements of energy expenditure of the respiratory muscles, such as pressure-time product, and measurements of inspiratory effort, such as the tension-time index, is currently accumulating. Several challenges, however, lay ahead regarding these indices. First, there is the need to identify the correct level of pressure generation and respiratory muscle effort that should be attained in the day-to-day management of mechanically ventilated patients. The correct titration of ventilator setting should not cause iatrogenic muscle damage because the support is excessive or insufficient. One of the challenges in reaching this goal is that for the same patient, different underlying pathologic conditions (eg, sepsis or ventilator-associated muscle injury) may require different levels of support. Second, many of the measurements of pressure generation and effort have been confined to the research laboratory. Modifications of the technology to achieve accurate measurements in the intensive care unit-outside of the research laboratory--are needed. To facilitate individual titration of ventilator settings, the new technologies must provide easier access to quantification of drive, pressure output, and effort. Finally, more research is needed to define the effect of monitoring respiratory output on patient outcome and containment of costs. PMID:15936689

  4. Scintigraphic assessment of regional cardiac adrenergic innervation

    SciTech Connect

    Dae, M.W.; O'Connell, J.W.; Botvinick, E.H.; Ahearn, T.; Yee, E.; Huberty, J.P.; Mori, H.; Chin, M.C.; Hattner, R.S.; Herre, J.M.

    1989-03-01

    To assess the feasibility of noninvasively imaging the regional distribution of myocardial sympathetic innervation, we evaluated the distribution of sympathetic nerve endings, using 123I metaiodobenzylguanidine (MIBG), and compared this with the distribution of myocardial perfusion, using 201Tl. Twenty dogs were studied: 11 after regional denervation, and nine as controls. Regional denervation was done by left stellate ganglion removal, right stellate ganglion removal, and application of phenol to the epicardial surface. Computer-processed functional maps displayed the relative distribution of MIBG and thallium in multiple projections in vivo and excised heart slices in all animals. In six animals, dual isotope emission computed tomograms were acquired in vivo. Tissue samples taken from innervated and denervated regions of the MIBG images were analyzed for norepinephrine content to validate image findings. Normal controls showed homogeneous and parallel distributions of MIBG and thallium in the major left ventricular mass. In the left stellectomized hearts, MIBG was reduced relative to thallium in the posterior left ventricle; whereas in right stellectomized hearts, reduced MIBG was in the anterior left ventricle. Phenol-painted hearts showed a broad area of decreased MIBG extending beyond the area of phenol application. In both stellectomized and phenol-painted hearts, thallium distribution remained homogeneous and normal. Norepinephrine content was greater in regions showing normal MIBG (550 +/- 223 ng/g) compared with regions showing reduced MIBG (39 +/- 44 ng/g) (p less than 0.001), confirming regional denervation. Combined MIBG-thallium functional maps display the regional distribution of sympathetic innervation.

  5. The 24 h pattern of arterial pressure in mice is determined mainly by heart rate?driven variation in cardiac output

    PubMed Central

    Kurtz, Theodore W.; Lujan, Heidi L.; DiCarlo, Stephen E.

    2014-01-01

    Abstract Few studies have systematically investigated whether daily patterns of arterial blood pressure over 24 h are mediated by changes in cardiac output, peripheral resistance, or both. Understanding the hemodynamic mechanisms that determine the 24 h patterns of blood pressure may lead to a better understanding of how such patterns become disturbed in hypertension and influence risk for cardiovascular events. In conscious, unrestrained C57BL/6J mice, we investigated whether the 24 h pattern of arterial blood pressure is determined by variation in cardiac output, systemic vascular resistance, or both and also whether variations in cardiac output are mediated by variations in heart rate and or stroke volume. As expected, arterial pressure and locomotor activity were significantly (P < 0.05) higher during the nighttime period compared with the daytime period when mice are typically sleeping (+12.5 1.0 mmHg, [13%] and +7.7 1.3 activity counts, [254%], respectively). The higher arterial pressure during the nighttime period was mediated by higher cardiac output (+2.6 0.3 mL/min, [26%], P < 0.05) in association with lower peripheral resistance (?1.5 0.3 mmHg/mL/min, [?13%] P < 0.05). The increased cardiac output during the nighttime was mainly mediated by increased heart rate (+80.0 16.5 beats/min, [18%] P < 0.05), as stroke volume increased minimally at night (+1.6 0.5 ?L per beat, [6%] P < 0.05). These results indicate that in C57BL/6J mice, the 24 h pattern of blood pressure is hemodynamically mediated primarily by the 24 h pattern of cardiac output which is almost entirely determined by the 24 h pattern of heart rate. These findings suggest that the differences in blood pressure between nighttime and daytime are mainly driven by differences in heart rate which are strongly correlated with differences in locomotor activity. PMID:25428952

  6. Ultrasound cardiac output units.

    PubMed

    1988-01-01

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

  7. Ultrasound cardiac output units.

    PubMed

    1988-12-01

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

  8. Outcomes Assessment: Not Synonymous with Inputs and Outputs.

    ERIC Educational Resources Information Center

    Dugan, Robert E.; Hernon, Peter

    2002-01-01

    Presents a rationale for the use of outcomes assessment and identifies three competing assessment perspectives that examine quality: looking at users from the perspective of the academic library; looking at libraries from the users' perspectives; and libraries in the life of the institution. Discusses information literacy, and differentiating

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

    PubMed

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

    2010-09-01

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

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

    PubMed Central

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

    2013-01-01

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

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

    PubMed Central

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

    2014-01-01

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

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

    PubMed Central

    2014-01-01

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

  13. The effects of cardiac output and pulmonary arterial hypertension on volumetric capnography derived-variables during normoxia and hypoxia.

    PubMed

    Mosing, Martina; Kutter, Annette P N; Iff, Samuel; Raszplewicz, Joanna; Mauch, Jacqueline; Bohm, Stephan H; Tusman, Gerardo

    2015-02-01

    The aim of this study was to test the effect of cardiac output (CO) and pulmonary artery hypertension (PHT) on volumetric capnography (VCap) derived-variables. Nine pigs were mechanically ventilated using fixed ventilatory settings. Two steps of PHT were induced by IV infusion of a thromboxane analogue: PHT25 [mean pulmonary arterial pressure (MPAP) of 25 mmHg] and PHT40 (MPAP of 40 mmHg). CO was increased by 50% from baseline (COup) with an infusion of dobutamine?5 ?g kg(-1) min(-1) and decreased by 40% from baseline (COdown) infusing sodium nitroglycerine?30 ?g kg(-1) min(-1) plus esmolol 500 ?g kg(-1) min(-1). Another state of PHT and COdown was induced by severe hypoxemia (FiO2 0.07). Invasive hemodynamic data and VCap were recorded and compared before and after each step using a mixed random effects model. Compared to baseline, the normalized slope of phase III (SnIII) increased by 32% in PHT25 and by 22% in PHT40. SnIII decreased non-significantly by 4% with COdown. A combination of PHT and COdown associated with severe hypoxemia increased SnIII by 28% compared to baseline. The elimination of CO2 per breath decreased by 7% in PHT40 and by 12% in COdown but increased only slightly with COup. Dead space variables did not change significantly along the protocol. At constant ventilation and body metabolism, pulmonary artery hypertension and decreases in CO had the biggest effects on the SnIII of the volumetric capnogram and on the elimination of CO2. PMID:24908108

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

    PubMed Central

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

    2015-01-01

    Background Hemodynamic abnormalities and acute kidney injury (AKI) are often present in infected cirrhotic patients. Hence, an early diagnosis of AKI is necessary, which might require the validation of new predictors as the determinations of urinary neutrophil gelatinase-associated lipocalin (uNGAL) and cardiac output. Methods We evaluated 18 infected cirrhotic patients subdivided into two groups at admission (0 hours). In Group I, we collected urine samples at 0 hours, 6 hours, 24 hours, and 48 hours for uNGAL and fractional excretion of sodium determinations. In Group II, we measured cardiac output using echocardiography. Results The age of patients was 55.01.9 years, and 11 patients were males. The Model for End-Stage Liver Disease score was 211, whereas the ChildPugh score was C in 11 patients and B in 7 patients. Both patients in Group I and Group II showed similar baseline characteristics. In Group I, we diagnosed AKI in 5 of 9 patients, and the mean time to this diagnosis by measuring serum creatinine was 5.4 days. Patients with AKI showed higher uNGAL levels than those without AKI from 6 hours to 48 hours. The best accuracy using the cutoff values of 68ng uNGAL/mg creatinine was achieved at 48 hours when we distinguished patients with and without AKI in all cases. In Group II, we diagnosed AKI in 4 of 9 patients, and cardiac output was significantly higher in patients who developed AKI at 0 hours. Conclusion Both uNGAL and cardiac output determinations allow the prediction of AKI in infected cirrhotic patients earlier than increments in serum creatinine. PMID:26484038

  15. Assessment of calcium scoring performance in cardiac computed tomography.

    PubMed

    Ulzheimer, Stefan; Kalender, Willi A

    2003-03-01

    Electron beam tomography (EBT) has been used for cardiac diagnosis and the quantitative assessment of coronary calcium since the late 1980s. The introduction of mechanical multi-slice spiral CT (MSCT) scanners with shorter rotation times opened new possibilities of cardiac imaging with conventional CT scanners. The purpose of this work was to qualitatively and quantitatively evaluate the performance for EBT and MSCT for the task of coronary artery calcium imaging as a function of acquisition protocol, heart rate, spiral reconstruction algorithm (where applicable) and calcium scoring method. A cardiac CT semi-anthropomorphic phantom was designed and manufactured for the investigation of all relevant image quality parameters in cardiac CT. This phantom includes various test objects, some of which can be moved within the anthropomorphic phantom in a manner that mimics realistic heart motion. These tools were used to qualitatively and quantitatively demonstrate the accuracy of coronary calcium imaging using typical protocols for an electron beam (Evolution C-150XP, Imatron, South San Francisco, Calif.) and a 0.5-s four-slice spiral CT scanner (Sensation 4, Siemens, Erlangen, Germany). A special focus was put on the method of quantifying coronary calcium, and three scoring systems were evaluated (Agatston, volume, and mass scoring). Good reproducibility in coronary calcium scoring is always the result of a combination of high temporal and spatial resolution; consequently, thin-slice protocols in combination with retrospective gating on MSCT scanners yielded the best results. The Agatston score was found to be the least reproducible scoring method. The hydroxyapatite mass, being better reproducible and comparable on different scanners and being a physical quantitative measure, appears to be the method of choice for future clinical studies. The hydroxyapatite mass is highly correlated to the Agatston score. The introduced phantoms can be used to quantitatively assess the performance characteristics of, for example, different scanners, reconstruction algorithms, and quantification methods in cardiac CT. This is especially important for quantitative tasks, such as the determination of the amount of calcium in the coronary arteries, to achieve high and constant quality in this field. PMID:12594550

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

    NASA Technical Reports Server (NTRS)

    Carnes, J. G.

    1978-01-01

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

  17. A systematic approach for assessing Ca? handling in cardiac myocytes.

    PubMed

    Sipido, Karin R; Macquaide, Niall; Bito, Virginie

    2015-05-01

    In cardiac myocytes, Ca(2+) release from the sarcoplasmic reticulum (SR) Ca(2+) store through the opening of ryanodine receptors (RyRs) is the major source of Ca(2+) for activation of myofilaments and contraction. Over the past 20 years, tools have become available to study this release process in detail, allowing new insights into the regulation of SR Ca(2+) release and RyR function. To assess these processes, we recommend and here review a systematic approach that evaluates the essential transport mechanisms and Ca(2+) fluxes in isolated single cardiac myocytes by using fluorescent Ca(2+) indicators and whole-cell recording of membrane voltage and ionic currents under voltage clamp. The approach includes an assessment of the L-type Ca(2+) current as a trigger for opening of RyRs and release of SR Ca(2+), of the SR Ca(2+) content, of intrinsic properties of RyRs, and of Ca(2+)-removal systems. PMID:25934941

  18. Validation of Pre-operative Patient Self-Assessment of Cardiac Risk for Non-Cardiac Surgery: Foundations for Decision Support

    PubMed Central

    Manaktala, Sharad; Rockwood, Todd; Adam, Terrence J.

    2013-01-01

    Objectives: To better characterize patient understanding of their risk of cardiac complications from non-cardiac surgery and to develop a patient driven clinical decision support system for preoperative patient risk management. Methods: A patient-driven preoperative self-assessment decision support tool for perioperative assessment was created. Patient self-perception of cardiac risk and self-report data for risk factors were compared with gold standard preoperative physician assessment to evaluate agreement. Results: The patient generated cardiac risk profile was used for risk score generation and had excellent agreement with the expert physician assessment. However, patient subjective self-perception risk of cardiovascular complications had poor agreement with expert assessment. Conclusion: A patient driven cardiac risk assessment tool provides a high degree of agreement with expert provider assessment demonstrating clinical feasibility. The limited agreement between provider risk assessment and patient self-perception underscores a need for further work including focused preoperative patient education on cardiac risk. PMID:24551384

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

    NASA Astrophysics Data System (ADS)

    Schrenk, M.; Seager, S.

    2007-12-01

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

  20. Automatic Assessment of Socioeconomic Impact on Cardiac Rehabilitation

    PubMed Central

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

    2013-01-01

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

  1. Cardiac output measured by uncalibrated arterial pressure waveform analysis by recently released software version 3.02 versus thermodilution in septic shock.

    PubMed

    Slagt, Cornelis; de Leeuw, Marcel A; Beute, Jan; Rijnsburger, Emmy; Hoeksema, Martijn; Mulder, Jan W R; Malagon, Ignacio; Groeneveld, A B Johan

    2013-04-01

    To evaluate the 3.02 software version of the FloTrac/Vigileo system for estimation of cardiac output by uncalibrated arterial pressure waveform analysis, in septic shock. Nineteen consecutive patients in septic shock were studied. FloTrac/Vigileo measurements (COfv) were compared with pulmonary artery catheter thermodilution-derived cardiac output (COtd). The mean cardiac output was 7.7Lmin(-1) and measurements correlated at r=0.53 (P<0.001, n=314). In Bland-Altman plot for repeated measurements, the bias was 1.7Lmin(-1) and 95% limits of agreement (LA) were -3.0 to 6.5Lmin(-1), with a %error of 53%. The bias of COfv inversely related to systemic vascular resistance (SVR) (r=-0.54, P<0.001). Above a SVR of 700 dynscm(-5) (n=74), bias was 0.3 Lmin(-1) and 95% LA were -1.6 to 2.2Lmin(-1) (%error 32%). Changes between consecutive measurements (n=295) correlated at 0.67 (P<0.001), with a bias of 0.1% (95% limits of agreement -17.5 to 17.0%). All changes >10% in both COtd and COfv (n=46) were in the same direction. Eighty-five percent of the measurements were within the 30-330 of the polar axis. COfv with the latest software still underestimates COtd at low SVR in septic shock. The tracking capacities of the 3.02 software are moderate-good when clinically relevant changes are considered. PMID:23154918

  2. Assessment of cardiac autonomic tone in conscious rats.

    PubMed

    Sayin, Halil; Chapuis, Bruno; Chevalier, Philippe; Barrs, Christian; Julien, Claude

    2016-01-01

    Cardiac autonomic tone can be assessed either by estimating separately vagal and sympathetic tones or by evaluating the net effect of their interaction, the so-called sympathovagal balance (SVB). To compare the most commonly used methods in rats, telemetric recordings of the electrocardiogram were performed in normotensive WKY rats, and in groups of spontaneously hypertensive (SHR) rats that were either untreated or chronically treated with the cholinesterase inhibitor, pyridostigmine, to enhance vagal tone. Cardiac autonomic blockers were administered alone and in combination, so that heart rate (HR) could be measured (1) under resting conditions, (2) with either autonomic branch blocked, and (3) with both branches blocked (which provided intrinsic HR, iHR). SVB was assessed as the ratio of resting HR to iHR. This calculation pointed to a sympathetic predominance in untreated SHRs and even more so in WKY rats, and to a marked vagal predominance in pyridostigmine-treated SHRs. By contrast, the ratio between low and high frequency components (LF/HF) of RR interval spectra did not significantly differ between the groups. Each autonomic tone was quantified as the HR change induced by its selective blocker or as the difference between iHR and HR after blockade of its counterpart. Both pharmacological methods indicated vagal enhancement in treated SHRs, but provided opposite results in terms of vagal vs. sympathetic predominance. These data seriously question the use of the LF/HF ratio as an index of SVB, and the possibility to reliably estimate vagal and sympathetic tones separately through current pharmacological approaches in conscious rats. PMID:26769133

  3. Preoperative Cardiac Assessment beforeCarotid Surgery: Should PerhapsThings Change?

    PubMed

    Galyfos, George; Aggeli, Konstantina; Sigala, Fragiska; Karanikola, Evridiki; Zografos, Georgios; Filis, Konstantinos

    2016-01-01

    Carotid endarterectomy has been associated with perioperative symptomatic or asymptomatic myocardial ischemia and cardiac mortality although it has been classified as a procedure of intermediate cardiac risk. Recent data indicate that the Cardiac Risk Index score for preoperative assessment by the latest guidelines is not suitable for vascular surgery procedures in general and carotid procedures in particular. This review aims to present and analyze all these results, concluding that current recommendations for this specific procedure should perhaps be reevaluated. PMID:26303267

  4. Cardiac radionuclide imaging to assess patients with heart failure.

    PubMed

    Travin, Mark I

    2014-07-01

    Heart failure (HF) is a major problem, with a high prevalence, morbidity, mortality, and cost, and is expected to become more widespread. Radionuclide imaging currently plays an important role in evaluating these patients, with much potential for increased utility. Myocardial perfusion imaging (MPI) with radiotracers is commonly used to differentiate an ischemic from a nonischemic etiology of HF and cardiomyopathy. In some instances, MPI effectively distinguishes among these, but often, standard MPI is deficient in that a nonischemic cardiomyopathy can have focal defects in tracer uptake and coronary artery disease with global balanced ischemia can result in a normal-appearing perfusion pattern. Developments in measuring quantitative blood flow promise to provide a more accurate determination of HF etiology. If coronary artery disease is established, MPI has long established use for assessment of myocardial viability and identification of patients likely to benefit from revascularization. Although a recent multicenter trial substudy has questioned the benefits of viability imaging, specific limitations of this study must be balanced against previously demonstrated utility. At the same time, viability imaging may need to be directed more skillfully toward carefully selected patients. In patients with HF who are not candidates for revascularization, myocardial remodeling often leads to poor patient outcome. Newer nuclear analyses of myocardial shape and of dyssynchronous contraction or relaxation can risk stratify patients and may help guide therapy. Investigative molecular imaging techniques promise to better understand underlying pathophysiology and guide therapy on an individual basis. Finally, recent approval of a tracer for cardiac autonomic innervation imaging should greatly expand the use of radionuclide imaging in HF, potentially guiding proper use of life saving but expensive and high-risk mechanical therapies. Given the molecular basis of much of the pathophysiology of HF, the contribution of cardiac radionuclide imaging to improve patient care should increase. PMID:24948152

  5. Serum uric acid is inversely proportional to estimated stroke volume and cardiac output in a large sample of pharmacologically untreated subjects: data from the Brisighella Heart Study.

    PubMed

    Cicero, Arrigo Francesco Giuseppe; Rosticci, Martina; Parini, Angelo; Baronio, Cristina; D'Addato, Sergio; Borghi, Claudio

    2014-09-01

    Serum uric acid is representative for xanthine-oxidase, the key enzyme involved in the production of uric acid, which is up-regulated in the failing heart, and may play an important role in the pathophysiologic process that leads to heart failure. In our study, we investigated the relation between stroke volume, cardiac output and serum uric acid in a large sample of overall healthy pharmacologically untreated subjects. The Brisighella Heart Study included 2,939 men and women between the ages of 14-84 without prior coronary heart disease or cerebrovascular disease who were not taking antihypertensive therapy at baseline. For this study, we selected 734 adult subjects enrolled in the last Brisighella population survey not taking antihypertensive, antidiabetic, lipid-lowering and uric acid-lowering drugs, and who were also not affected by chronic heart failure or by gout. The main predictors of cardiac functionality parameters were mean arterial pressure (MAP), HR, SUA and age (all p < 0.001), while gender, BMI, LDL-cholesterol, HDL-cholesterol, triglycerides, fasting plasma glucose, creatinine, estimated glomerular filtration rate, physical activity and smoking habit were not significantly associated (all p > 0.05). In particular, there is a strong relation between estimated cardiac output and serum uric acid (B = -0.219, p < 0.001) and between stroke volume and serum uric acid (B = -3.684, p < 0.001). These observations might have an impact on future considerations about serum uric acid as an early inexpensive marker of heart function decline in the general population. PMID:24214336

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

    PubMed

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

    2013-09-01

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

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

    EPA Science Inventory

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

  8. Imminent Cardiac Risk Assessment via Optical Intravascular Biochemical Analysis

    SciTech Connect

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

    2009-01-01

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

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

    PubMed

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

    2016-02-01

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

  10. Improving cardiac assessment and monitoring in methadone prescribing at an addiction service

    PubMed Central

    Ramage, Mark; Fadaka, Kate

    2014-01-01

    The assessment and monitoring of cardiac risk in patients prescribed methadone is important for patient safety. Although uncommon, QTc interval prolongation is potentially life-threatening. Known risk factors for QTc prolongation include methadone, particularly at doses above 100 milligrams daily. This project aimed to improve the cardiac assessment and monitoring at Barnet Drug and Alcohol Service through raising the awareness of this clinically importance issue as well as through amending the medical assessment guidance to promote the comprehensive assessment of QTc prolongation risk factors and ensure the identification of cardiac risk in patients prescribed methadone. The project also provided guidance on QTc prolongation management and monitoring (including performance of an electrocardiogram) at the service to provide a baseline measurement and arrangement of annual monitoring. Prior to the intervention, a randomised sample of 26 patients that had been prescribed methadone revealed no comprehensive cardiac risk assessments. Analysing 52 medical assessments in the month following the intervention suggested an improvement in assessment and management of QTc interval prolongation risk, with seven comprehensive cardiac risks assessments performed and one patient having QTc interval prolongation identified following an electrocardiogram and appropriately managed. This project was limited by small sample sizes and the relatively low incidence of QTc prolongation. The poor rate of attendance for requested electrocardiograms in this population was noted as a challenge that needed further consideration.

  11. Preoperative assessment of cardiac risk in noncardiac major vascular surgery.

    PubMed

    Roghi, A; Palmieri, B; Crivellaro, W; Sara, R; Puttini, M; Faletra, F

    1999-01-15

    We evaluated whether a preoperative clinical algorithm allows an adequate stratification in cardiac risk and the predictive value of dipyridamole thallium-201 scintigraphy and rest echocardiography for postoperative adverse cardiac outcomes. Three hundred twenty patients undergoing 338 vascular surgery procedures were prospectively stratified into low, intermediate, and high risk. The low- and intermediate-risk patients underwent surgery without further diagnostic evaluation. In 7 high-risk patients the vascular procedure was canceled (1 died of myocardial infarction at 6-month follow-up), 9 underwent presurgical myocardial revascularization (1 died of myocardial infarction), and 49 underwent vascular surgery with perioperative intensive care treatment. Hospital mortality was 3.8%. Cardiac mortality and morbidity were 1.5% and 10.4%, respectively. We observed a significant difference in "hard" (death, myocardial infarction, pulmonary edema, major arrhythmias) and "soft" (myocardial ischemia, minor arrhythmias) events between groups, p <0.001. Previous pulmonary edema was a predictive variable of cardiac outcomes (multiple logistic regression analysis). Ninety-nine of 220 intermediate-risk patients randomly underwent dipyridamole thallium-201 scintigraphy: 37 had redistribution, 10 persistent, and 52 no defects; 7 of 13 soft and hard cardiac events occurred in patients without redistribution defects. Sensitivity, specificity, and positive and negative predictive values of redistribution defects for postoperative adverse outcomes were 38%, 63%, 14%, 87%, respectively. This algorithm may provide a safe and cost-effective approach (average cost saving per patient $1,500) to cardiac risk stratification. These results suggest that routine use of dipyridamole thallium-201 scintigraphy for screening of intermediate-risk patients may not be warranted. PMID:10073816

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

    SciTech Connect

    Cushman, R.M.

    1990-01-01

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

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

    PubMed Central

    Nabi, Faisal

    2013-01-01

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

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

    NASA Technical Reports Server (NTRS)

    Shykoff, Barbara E.; Swanson, Harvey T.

    1987-01-01

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

  15. The feasibility and applications of non-invasive cardiac output monitoring, thromboelastography and transit-time flow measurement in living-related renal transplantation surgery: results of a prospective pilot observational study

    PubMed Central

    2014-01-01

    Introduction Delayed graft function (DGF) remains a significant and detrimental postoperative phenomenon following living-related renal allograft transplantation, with a published incidence of up to 15%. Early therapeutic vasodilatory interventions have been shown to improve DGF, and modifications to immunosuppressive regimens may subsequently lessen its impact. This pilot study assesses the potential applicability of perioperative non-invasive cardiac output monitoring (NICOM), transit-time flow monitoring (TTFM) of the transplant renal artery and pre-/perioperative thromboelastography (TEG) in the early prediction of DGF and perioperative complications. Methods Ten consecutive living-related renal allograft recipients were studied. Non-invasive cardiac output monitoring commenced immediately following induction of anaesthesia and was maintained throughout the perioperative period. Doppler-based TTFM was performed during natural haemostatic pauses in the transplant surgery: immediately following graft reperfusion and following ureteric implantation. Central venous blood sampling for TEG was performed following induction of anaesthesia and during abdominal closure. Results A single incidence of DGF was seen within the studied cohort and one intra-operative (thrombotic) complication noted. NICOM confirmed a predictable trend of increased cardiac index (CI) following allograft reperfusion (mean CI - clamped: 3.17??0.29L/min/m2, post-reperfusion: 3.50??0.35L/min/m2; P?

  16. [Assessment of fetal cardiac function--established and novel methods].

    PubMed

    Enzensberger, C; Tenzer, A; Degenhardt, J; Kawecki, A; Axt-Fliedner, R

    2014-04-01

    Numerous maternal (diabetes, preeclampsia) and fetal pathologies (uteroplacental dysfunction, hydrops, infection, congenital heart disease) can lead to cardiac dysfunction in the fetus. This includes increase of pre- and afterload, compression of the heart, myocardial damage, hypoxia and hyperglycemia. Beside already established methods like m-mode and pulse-waved Doppler, new promising technologies like tissue Doppler and speckle tracking are available for monitoring fetal cardiac function. Some of these new techniques have not been part of clinical routine yet because no validation has been performed so far and/or the technique is too time-consuming. Other technologies are currently being tested and only part of research projects. Innovations like speckle tracking that have its seeds in adult cardiology, are still limited because of the smallness of the fetal heart, the higher heart rate, fetal and maternal moving artefacts and finally because of a missing fetal ECG signal. Therefore their application should be performed critically. PMID:24788834

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

    NASA Astrophysics Data System (ADS)

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

    2013-04-01

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

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

    SciTech Connect

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

    2010-04-15

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

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed

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

    2013-10-01

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

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

    SciTech Connect

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

    2003-05-01

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

  2. Assessing impacts of climate change in a semi arid watershed using downscaled IPCC climate output

    NASA Astrophysics Data System (ADS)

    Rajagopal, S.; Dominguez, F.; Gupta, H. V.; Troch, P. A.; Castro, C. L.

    2009-12-01

    This presentation discusses our research aimed at helping water managers at Salt River Project (SRP), Phoenix, assess long term climate change impacts for the Salt and Verde River basins, and make informed policy decisions. Our goal is to assess the change in future 100 year water balance variables in comparison to past observations by development, application and testing of a physically based distributed hydrologic model forced by downscaled IPCC climate information. The variable infiltration capacity (VIC) model is set up to simulate historical observed streamflow at the outlet of Salt and Verde River basins using gridded observed precipitation and temperature data. The model is calibrated using the Shuffled Complex Evolution (SCE-UA) method incorporating observed climate elasticities of the Salt and Verde River basins. The MPI-ECHAM5, UK-HADCM3 model output for three emission scenarios used in the IPCC fourth assessment were chosen and statistically downscaled to be incorporated with the VIC model. This forcing dataset was used to analyze the basin scale responses to climate change. In this presentation, the scenarios based on future climate forcing data will be presented. In addition results from a synthetic study using downscaled future temperature and past precipitation and vice versa will be presented to check the robustness of the model to non-stationary input.

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

    PubMed

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

    2000-12-01

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

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

    PubMed Central

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

    2014-01-01

    Blood flow through intrapulmonary arteriovenous anastomoses (IPAVAs) has been demonstrated to increase in healthy humans during a variety of conditions; however, whether or not this blood flow represents a source of venous admixture (/) that impairs pulmonary gas exchange efficiency (i.e. increases the alveolar-to-arterial difference (AaDO2)) remains controversial and unknown. We hypothesized that blood flow through IPAVAs does provide a source of /. To test this, blood flow through IPAVAs was increased in healthy humans at rest breathing room air and 40% O2: (1) during intravenous adrenaline (epinephrine) infusion at 320 ng kg?1 min?1 (320 ADR), and (2) with vagal blockade (2 mg atropine), before and during intravenous adrenaline infusion at 80 ng kg?1 min?1 (ATR + 80 ADR). When breathing room air the AaDO2 increased by 6 2 mmHg during 320 ADR and by 5 2 mmHg during ATR + 80 ADR, and the change in calculated / was +2% in both conditions. When breathing 40% O2, which minimizes contributions from diffusion limitation and alveolar ventilation-to-perfusion inequality, the AaDO2 increased by 12 7 mmHg during 320 ADR, and by 9 6 mmHg during ATR + 80 ADR, and the change in calculated / was +2% in both conditions. During 320 ADR cardiac output () and pulmonary artery systolic pressure (PASP) were significantly increased; however, during ATR + 80 ADR only was significantly increased, yet blood flow through IPAVAs as detected with saline contrast echocardiography was not different between conditions. Accordingly, we suggest that blood flow through IPAVAs provides a source of intrapulmonary shunt, and is mediated primarily by increases in rather than PASP. PMID:25085889

  5. Nexfin Noninvasive Continuous Hemodynamic Monitoring: Validation against Continuous Pulse Contour and Intermittent Transpulmonary Thermodilution Derived Cardiac Output in Critically Ill Patients

    PubMed Central

    Van De Vijver, Katrijn; De laet, Inneke; Schoonheydt, Karen; Dits, Hilde; Bein, Berthold; Malbrain, Manu L. N. G.

    2013-01-01

    Introduction. Nexfin (Bmeye, Amsterdam, Netherlands) is a noninvasive cardiac output (CO) monitor based on finger arterial pulse contour analysis. The aim of this study was to validate Nexfin CO (NexCO) against thermodilution (TDCO) and pulse contour CO (CCO) by PiCCO (Pulsion Medical Systems, Munich, Germany). Patients and Methods. In a mix of critically ill patients (n = 45), NexCO and CCO were measured continuously and recorded at 2-hour intervals during the 8-hour study period. TDCO was measured at 048?hrs. Results. NexCO showed a moderate to good (significant) correlation with TDCO (R2 0.68, P < 0.001) and CCO (R2 0.71, P < 0.001). Bland and Altman analysis comparing NexCO with TDCO revealed a bias ( limits of agreement, LA) of 0.4 2.32?L/min (with 36% error) while analysis comparing NexCO with CCO showed a bias (LA) of 0.2 2.32?L/min (37% error). NexCO is able to follow changes in TDCO and CCO during the same time interval (level of concordance 89.3% and 81%). Finally, polar plot analysis showed that trending capabilities were acceptable when changes in NexCO (?NexCO) were compared to ?TDCO and ?CCO (resp., 89% and 88.9% of changes were within the level of 10% limits of agreement). Conclusion. we found a moderate to good correlation between CO measurements obtained with Nexfin and PiCCO. PMID:24319373

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

    PubMed

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

    2016-04-01

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

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

    NASA Astrophysics Data System (ADS)

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

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

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

    PubMed

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

    2015-12-01

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

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

    SciTech Connect

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

    1997-03-01

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

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

    PubMed Central

    Dursun, Huseyin; Kilicaslan, Baris; Aydin, Mehmet

    2014-01-01

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

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

    PubMed

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

    2012-01-17

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

  12. Can general circulation models be assessed and their output enhanced with drifter data?

    NASA Astrophysics Data System (ADS)

    Toner, M.; Kirwan, A. D.; Kantha, L. H.; Choi, J. K.

    2001-09-01

    Drifter data from the Gulf of Mexico are used to assess and enhance the output of a primitive equation general circulation model. The analysis is made in a 450 km 450 km open subdomain encompassing a Loop Current ring. The model velocity field is compared with position data from four drifters at the drogue depth of 50 m using geometrical orthogonal functions (GOF). An Eulerian velocity field is reconstructed from the model velocity field and drifter velocities. This reconstructed velocity improves 8-day numerical trajectories relative to the model field by at least an order of magnitude, as quantified by two Lagrangian error metrics referenced to the real drifter paths. An Eulerian metric that compares the two fields, however, does not exceed 7% for the 20-day assessment period. Thus the drifter data may be reproduced with modest impact on the model velocity. Enhancement of the model velocity field is determined by two tests: the ability of the GOF velocity field to (1) improve the forecast of drifter positions using only a posteriori data and (2) improve the forecast of withheld drifter data. Using a posteriori data, the 20-day temporal mean of the position error is improved for all drifters by 87-89% for 6-hour and 26-38% for 30-hour forecasts. For 6 days, a withheld drifter is 35-40 km from a drifter whose velocity is used in the reconstructed velocity field. The temporal mean of the position error during this period is improved by 20% for 6-hour and 26% for 30-hour forecasts.

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

    NASA Astrophysics Data System (ADS)

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

    2016-02-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2015-12-01

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

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

    ERIC Educational Resources Information Center

    Wamala, Robert; Ssembatya, Vincent A.

    2015-01-01

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

  16. Noninvasive Physiologic Assessment of Coronary Stenoses Using Cardiac CT

    PubMed Central

    Fan, Zhanming

    2015-01-01

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

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

    PubMed

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

    2013-11-01

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

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

    SciTech Connect

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

    2008-02-13

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

  19. Physiologic Assessment of Coronary Artery Disease by Cardiac Computed Tomography

    PubMed Central

    Kochar, Minisha

    2013-01-01

    Coronary artery disease (CAD) remains the leading cause of death and morbidity worldwide. To date, diagnostic evaluation of patients with suspected CAD has relied upon the use of physiologic non-invasive testing by stress electrocardiography, echocardiography, myocardial perfusion imaging (MPI) and magnetic resonance imaging. Indeed, the importance of physiologic evaluation of CAD has been highlighted by large-scale randomized trials that demonstrate the propitious benefit of an integrated anatomic-physiologic evaluation method by performing lesion-specific ischemia assessment by fractional flow reserve (FFR)-widely considered the "gold" standard for ischemia assessment-at the time of invasive angiography. Coronary CT angiography (CCTA) has emerged as an attractive non-invasive test for anatomic illustration of the coronary arteries and atherosclerotic plaque. In a series of prospective multicenter trials, CCTA has been proven as having high diagnostic performance for stenosis detection as compared to invasive angiography. Nevertheless, CCTA evaluation of obstructive stenoses is prone to overestimation of severity and further, detection of stenoses by CCTA does not reliably determine the hemodynamic significance of the visualized lesions. Recently, a series of technological innovations have advanced the possibility of CCTA to enable physiologic evaluation of CAD, thereby creating the potential of this test to provide an integrated anatomic-physiologic assessment of CAD. These advances include rest-stress MPI by CCTA as well as the use of computational fluid dynamics to non-invasively calculate FFR from a typically acquired CCTA. The purpose of this review is to summarize the most recent data addressing these 2 physiologic methods of CAD evaluation by CCTA. PMID:23964289

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

    PubMed Central

    2003-01-01

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

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

    PubMed

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

    2015-02-01

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

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

    EPA Science Inventory

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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

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

    NASA Technical Reports Server (NTRS)

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

    2010-01-01

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

  5. MRI assessment of cardiac tumours: part 1, multiparametric imaging protocols and spectrum of appearances of histologically benign lesions

    PubMed Central

    Shahid, Muhammad; Ganeshan, Arul; Baijal, Shobhit; Simpson, Helen; Watkin, Richard W.

    2014-01-01

    Cardiac magnetic resonance imaging (MRI) is the reference standard technique for assessment and characterization of a suspected cardiac tumour. It provides an unrestricted field of view, high temporal resolution and non-invasive tissue characterization based on multi-parametric assessment of the chemical micro-environment. MRI exploits differences in hydrogen proton density in conjunction with T1 and T2 relaxation properties of different tissues to help differentiation normal from abnormal and benign from malignant lesions. In this article we review specific cardiac MRI techniques, tumour protocol design and the appearance of the spectrum of histologically benign tumours. PMID:25525581

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

    SciTech Connect

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

    1995-12-31

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

  7. Nuclear cardiac imaging for the assessment of myocardial viability

    PubMed Central

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

    2005-01-01

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

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

    PubMed

    Yang, Bufan; Chon, Ki H

    2011-01-01

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

  9. [A basis for application of cardiac contractility variability in the Evaluation and assessment of exercise and fitness].

    PubMed

    Bu, Bin; Wang, Aihua; Han, Haijun; Xiao, Shouzhong

    2010-06-01

    Cardiac contractility variability (CCV) is a new concept which is introduced in the research field of cardiac contractility in recent years, that is to say, there are some disparities between cardiac contractilities when heart contracts. The changing signals of cardiac contractility contain a plenty of information on the cardiovascular function and disorder. In order to collect and analyze the message, we could quantitatively evaluate the tonicity and equilibrium of cardiac sympathetic nerve and parasympathetic nerve, and the effects of bio-molecular mechanism on the cardiovascular activities. By analyzing CCV, we could further understand the background of human being's heritage characteristics, nerve types, the adjusting mechanism, the molecular biology, and the adjustment of cardiac automatic nerve. With the development of the computing techniques, the digital signal processing method and its application in medical field, this analysis has been progressing greatly. By now, the assessment of CCV, just like the analysis of heart rate variability, is mainly via time domain and frequency domain analysis. CCV is one of the latest research fields in human cardiac signals being scarcely reported in the field of sports medicine; however, its research progresses are of important value for cardiac physiology and pathology in sports medicine and rehabilitation medicine. PMID:20649051

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

    ERIC Educational Resources Information Center

    Houck, Eric A.; Eom, Moonyoung

    2012-01-01

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

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

    ERIC Educational Resources Information Center

    Aristovnik, Aleksander

    2013-01-01

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

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

    ERIC Educational Resources Information Center

    Aristovnik, Aleksander

    2013-01-01

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

  13. Wearable seismocardiography for the beat-to-beat assessment of cardiac intervals during sleep.

    PubMed

    Di Rienzo, Marco; Vaini, Emanuele; Castiglioni, Paolo; Lombardi, Prospero; Parati, Gianfranco; Lombardi, Carolina; Meriggi, Paolo; Rizzo, Francesco

    2014-01-01

    Seismocardiogram (SCG) can be detected during sleep by a textile-based wearable system. This pilot study preliminarily explores the feasibility of a beat-to-beat estimation of cardiac mechanical features (RR interval, RRI, Pre-Ejection Period, PEP, Isovolumic Contraction Time, ICT, Left Ventricular Ejection Time, LVET, Isovolumic Relaxation Time, IRT) from the joint ECG and SCG assessment during sleep. The analysis of two 30-min sleep data segments from one healthy subject, indicated that 1) respiration largely influence the dynamics of most of the parameters; 2) variability of cardiac intervals is only marginally influenced by the RRI variability; 3) appreciable spectral power at frequencies ? 0.1 is only observed in the RRI spectrum and not in the spectra of the other indexes; 4) IRT has a broadband variability, that is clearly different from the dynamics of the other indexes. These findings represent the very first description of the beat-to-beat variability of cardiac mechanical indexes. Further investigations on a larger population are in progress to confirm the present results. PMID:25571386

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

    PubMed Central

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

    2013-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2015-04-01

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

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

    PubMed Central

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

    2014-01-01

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

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

    PubMed Central

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

    2014-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2009-02-01

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

  19. A mobile phone-based care model for outpatient cardiac rehabilitation: the care assessment platform (CAP)

    PubMed Central

    2010-01-01

    Background Cardiac rehabilitation programs offer effective means to prevent recurrence of a cardiac event, but poor uptake of current programs have been reported globally. Home based models are considered as a feasible alternative to avoid various barriers related to care centre based programs. This paper sets out the study design for a clinical trial seeking to test the hypothesis that these programs can be better and more efficiently supported with novel Information and Communication Technologies (ICT). Methods/Design We have integrated mobile phones and web services into a comprehensive home- based care model for outpatient cardiac rehabilitation. Mobile phones with a built-in accelerometer sensor are used to measure physical exercise and WellnessDiary software is used to collect information on patients' physiological risk factors and other health information. Video and teleconferencing are used for mentoring sessions aiming at behavioural modifications through goal setting. The mentors use web-portal to facilitate personal goal setting and to assess the progress of each patient in the program. Educational multimedia content are stored or transferred via messaging systems to the patients phone to be viewed on demand. We have designed a randomised controlled trial to compare the health outcomes and cost efficiency of the proposed model with a traditional community based rehabilitation program. The main outcome measure is adherence to physical exercise guidelines. Discussion The study will provide evidence on using mobile phones and web services for mentoring and self management in a home-based care model targeting sustainable behavioural modifications in cardiac rehabilitation patients. Trial registration The trial has been registered in the Australian New Zealand Clinical Trials Registry (ANZCTR) with number ACTRN12609000251224. PMID:20109196

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

    PubMed

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

    2015-05-01

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

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

    PubMed

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

    2014-06-30

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

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

    PubMed

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

    2014-10-01

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

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

    NASA Technical Reports Server (NTRS)

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

    2013-01-01

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

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed

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

    2015-08-01

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

  6. Interstitial Myocardial Fibrosis Assessed as Extracellular Volume Fraction with Low-Radiation-Dose Cardiac CT

    PubMed Central

    Nacif, Marcelo Souto; Kawel, Nadine; Lee, Jason J.; Chen, Xinjian; Yao, Jianhua; Zavodni, Anna; Sibley, Christopher T.; Lima, Joo A. C.; Liu, Songtao

    2012-01-01

    Purpose: To develop a cardiac computed tomographic (CT) method with which to determine extracellular volume (ECV) fraction, with cardiac magnetic resonance (MR) imaging as the reference standard. Materials and Methods: Study participants provided written informed consent to participate in this institutional review boardapproved study. ECV was measured in healthy subjects and patients with heart failure by using cardiac CT and cardiac MR imaging. Paired Student t test, linear regression analysis, and Pearson correlation analysis were used to determine the relationship between cardiac CT and MR imaging ECV values and clinical parameters. Results: Twenty-four subjects were studied. There was good correlation between myocardial ECV measured at cardiac MR imaging and that measured at cardiac CT (r = 0.82, P < .001). As expected, ECV was higher in patients with heart failure than in healthy control subjects for both cardiac CT and cardiac MR imaging (P = .03, respectively). For both cardiac MR imaging and cardiac CT, ECV was positively associated with end diastolic and end systolic volume and inversely related to ejection fraction (P < .05 for all). Mean radiation dose was 1.98 mSv 0.16 (standard deviation) for each cardiac CT acquisition. Conclusion: ECV at cardiac CT and that at cardiac MR imaging showed good correlation, suggesting the potential for myocardial tissue characterization with cardiac CT. RSNA, 2012 PMID:22771879

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

    PubMed

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

    2016-04-01

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

  8. Cardiac gated ventilation

    SciTech Connect

    Hanson, C.W. III; Hoffman, E.A.

    1995-12-31

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

  9. Cardiac gated ventilation

    NASA Astrophysics Data System (ADS)

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

    1995-05-01

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

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

    PubMed Central

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

    2013-01-01

    Purpose: Single-photon emission computed tomography (SPECT) is widely used to detect myocardial ischemia and myocardial infarction. It is important to assess and compare different SPECT system designs in order to achieve the highest detectability of cardiac defects. Methods:Whitaker s study [Estimating random signal parameters from noisy images with nuisance parameters: linear and scanning-linear methods, Opt. Express 16(11), 81508173 (2008)]10.1364/OE.16.008150 on the scanning linear observer (SLO) shows that the SLO can be used to estimate the location and size of signals. One major advantage of the SLO is that it can be used with projection data rather than with reconstruction data. Thus, this observer model assesses the overall hardware performance independent of any reconstruction algorithm. In addition, the computation time of image quality studies is significantly reduced. In this study, three systems based on the design of the GE cadmium zinc telluride-based dedicated cardiac SPECT camera Discovery 530c were assessed. This design, which is officially named the Alcyone Technology: Discovery NM 530c, was commercialized in August, 2009. The three systems, GE27, GE19, and GE13, contain 27, 19, and 13 detectors, respectively. Clinically, a human heart can be virtually segmented into three coronary artery territories: the left-anterior descending artery, left-circumflex artery, and right coronary artery. One of the most important functions of a cardiac SPECT system is to produce images from which a radiologist can accurately predict in which territory the defect exists [http://www.asnc.org/media/PDFs/PPReporting081511.pdf, Guideline from American Society of Nuclear Cardiology]. A good estimation of the extent of the defect from the projection images is also very helpful for determining the seriousness of the myocardial ischemia. In this study, both the location and extent of defects were estimated by the SLO, and the system performance was assessed by localization receiver operating characteristic (LROC) [P. Khurd and G. Gindi, Decision strategies maximizing the area under the LROC curve, Proc. SPIE 5749, 150161 (2005)]10.1117/12.595915 or estimation receiver operating characteristic (EROC) [E. Clarkson, Estimation receiver operating characteristic curve and ideal observers for combined detection/estimation tasks, J. Opt. Soc. Am. A 24, B91B98 (2007)]10.1364/JOSAA.24.000B91 curves. Results: The area under the LROC/EROC curve (AULC/AUEC) and the true positive fraction (TPF) at a specific false positive fraction (FPF) can be treated as the figures of merit. For radii estimation with a 1 mm tolerance, the AUEC values of the GE27, GE19, and GE13 systems are 0.8545, 0.8488, and 0.8329, and the TPF at FPF = 5% are 77.1%, 76.46%, and 73.55%, respectively. The assessment of all three systems revealed that the GE19 system yields estimated information and cardiac defect detectability very close to those of the GE27 system while using eight fewer detectors. Thus, 30% of the expensive detector units can be removed with confidence. Conclusions: As the results show, a combination of the SLO and LROC/EROC curves can determine the configuration that yields the most relevant estimation/detection information. Thus, this is a useful method for assessing cardiac SPECT systems. PMID:23298097

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

    SciTech Connect

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

    2013-01-15

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

  12. Assessing the limits of bias-correcting climate model outputs for climate change impact studies

    NASA Astrophysics Data System (ADS)

    Chen, Jie; Brissette, Franois P.; Lucas-Picher, Philippe

    2015-02-01

    Bias correction of climate model outputs has emerged as a standard procedure in most recent climate change impact studies. A crucial assumption of all bias correction approaches is that climate model biases are constant over time. The validity of this assumption has important implications for impact studies and needs to be verified to properly address uncertainty in future climate projections. Using 10 climate model simulations, this study specifically tests the bias stationarity of climate model outputs over Canada and the contiguous United States (U.S.) by comparing model outputs with corresponding observations over two 20 year historical periods (1961-1980 and 1981-2000). The results show that precipitation biases are clearly nonstationary over much of Canada and the contiguous U.S. and where they vary over much shorter time scales than those normally considered in climate change impact studies. In particular, the difference in biases over two very close periods of the recent past are, in fact, comparable to the climate change signal between future (2061-2080) and historical (1961-1980) periods for precipitation over large parts of Canada and the contiguous U.S., indicating that the uncertainty of future impacts may have been underestimated in most impact studies. In comparison, temperature bias can be considered to be approximately stationary for most of Canada and the contiguous U.S. when compared with the magnitude of the climate change signal. Given the reality that precipitation is usually considered to be more important than temperature for many impact studies, it is advisable that natural climate variability and climate model sensitivity be better emphasized in future impact studies.

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

    NASA Astrophysics Data System (ADS)

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

    2015-07-01

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

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

    NASA Astrophysics Data System (ADS)

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

    1993-09-01

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

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

    PubMed Central

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

    2016-01-01

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

  16. The Hirsch-index: a simple, new tool for the assessment of scientific output of individual scientists

    PubMed Central

    Opthof, T.; Wilde, A.A.M.

    2009-01-01

    In this brief paper we explore the Hirsch-index together with a couple of other bibliometric parameters for the assessment of the scientific output of 29 Dutch professors in clinical cardiology. It appears that even within such a homogeneous group there is large interindividual variability. Although the differences are quite remarkable, it remains undetermined what they mean; at least it is premature to interpret them as differences in scientific quality. It goes without saying that even more prudence is required when different fields of medicine and life sciences are compared (for example within University Medical Centres). Recent efforts to produce an amalgam of scientific productivity, relevance and viability as a surrogate parameter for the assessment of scientific quality, as for example performed in the AMC in Amsterdam, should be discouraged in the absence of a firm scientific base. Unfortunately for politicians and managers of science only reading papers and studying are suitable for quality assessment of scientific output. Citations analyses can't substitute that. (Neth Heart J 2009;17:145-54.19421360) PMID:19421360

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

    PubMed

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

    2013-12-01

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

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

    ERIC Educational Resources Information Center

    Long, Patricia N.; Amey, Marilyn J.

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

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

    SciTech Connect

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

    1991-01-01

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

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

    PubMed

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

    2013-12-01

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

  1. Assessing Impacts of Climate Change in a Semi-Arid Watershed Using Downscaled IPCC Climate Output

    NASA Astrophysics Data System (ADS)

    Dominguez, F.; Rajagopal, S.; Gupta, H. V.; Troch, P. A.; Durcik, M.

    2008-12-01

    This presentation discusses our research aimed at helping water managers at Salt River Project (SRP), Phoenix, assess long term climate change impacts for the Salt and Verde River basins, and make informed policy decisions. Our goal is to assess the future 100 year water balance by development, application and testing of a physically based distributed hydrologic model forced by downscaled IPCC climate information. The variable infiltration capacity (VIC) model is set up to simulate historical observed streamflow at the outlet of Salt and Verde River basins using gridded observed precipitation and temperature data. The model is calibrated using the Shuffled Complex Evolution (SCE-UA) method incorporating observed climate elasticities of the Salt and Verde River basins. The most appropriate models and emission scenarios from the Global Climate Model's (GCM's) participating in the IPCC fourth assessment were then chosen and statistically downscaled to incorporate ENSO variability. The forcing dataset created using the downscaled data was used to analyze the basin scale responses to climate change. In this poster, the scenarios based on future climate forcing data will be presented.

  2. Risk assessment of exposure to particulate output of a demolition site.

    PubMed

    Brown, A; Barrett, J E S; Robinson, H; Potgieter-Vermaak, S

    2015-08-01

    Whilst vehicular and industrial contributions to the airborne particulate budget are well explored, the input due to building demolition is relatively unknown. Air quality is of importance to human health, and it is well known that composition of airborne particles can have a significant influence on both chronic and acute health effects. Road dust (RD) was collected before and after the demolition of a large building to elucidate changes in elemental profile. Rainfall and PM10 mass concentration data aided interpretation of the elemental data. Quantification of Al, As, Ba, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, Rh, S, Si, Sn, Ti, V and Zn was carried out. It was found that only Al, K, Mg, Si and S increased in concentration across all size fractions after the building demolition. Risk assessment was then carried out on elements with applicable reference dose values to assess the potential health risks due to the demolition. Significant risk to children was observed for chromium and aluminium exposure. PM10, monitored 40 metres from the demolition site, indicated no abnormal concentrations during the demolition; however, rainfall data were shown to affect the concentration of PM10. The elemental data observed in this study could possibly indicate the role of increased sulphur concentrations (in this case as a result of the demolition) on the buffer capacity of RD, hence leaching metals into rainwater. PMID:26173774

  3. Assessing impacts of climate change in a semi arid watershed using downscaled IPCC climate output

    NASA Astrophysics Data System (ADS)

    Rajagopal, S.; Dominguez, F.; Gupta, H. V.; Troch, P. A.; Castro, C. L.

    2010-12-01

    This presentation discusses our research aimed at helping water managers at Salt River Project (SRP), Phoenix, assess long term climate change impacts for the Salt and Verde River basins, and make informed policy decisions. Our goal was to assess the future 100 year water balance by development, application and testing of a physically based distributed hydrologic model forced by downscaled IPCC climate information. The variable infiltration capacity (VIC) model was set up to simulate historical observed streamflow at the outlet of Salt and Verde River basins using gridded observed precipitation and temperature data. The model was calibrated using the Shuffled Complex Evolution (SCE-UA) optimization algorithm. The models found to best simulate the climatology of the region, (UK-HADCM3, MPI-ECHAM5, NCAR-CCSM3) and emission scenarios (A1B, A2, B1) from the Global Climate Models (GCMs) participating in the IPCC fourth assessment were obtained from the bias-corrected and spatially downscaled climate projections derived from the World Climate Research Programme's (WCRP's) Coupled Model Intercomparison Project phase 3 multi-model dataset. The data was then temporally downscaled to serve as forcing for the VIC model. This downscaled forcing dataset was used to analyze the basin scale responses to climate change. Based on stakeholder feedback two additional GCM's one that represents a wet scenario and one that represents a dry scenario, were also downscaled as mentioned above and run through the hydrologic model. All the models show a statistically significant increase in temperature over the 21st century. Due to increased winter temperatures the multi-model mean shows a significant decrease in storage capacity in the basin, viz. snow water equivalent. This decrease is already evident in observed SNOTEL records of the basin. Since these watersheds are snow dominated, the cold season multi-model mean streamflow shows a decreasing trend by the end of the century though the warm season streamflow tends to increase in response to increased summer precipitation. Increased summer streamflow does not compensate for the decrease in winter streamflow. In addition to the above analysis a synthetic study was performed to quantify the uncertainty in coupled GCM-Hydrologic model predictions.

  4. Assessment of aortic and mitral annuli dynamics during the cardiac cycle using speckle tracking echocardiography

    PubMed Central

    Bai, Wenjuan; Li, Hui; Tang, Hong; Zhang, Qing; Zhu, Ye

    2014-01-01

    The aims of this study were i) to evaluate mitral and aortic annuli excursion, and aortomitral angle (AMA) during the cardiac cycle in healthy adults using two-dimensional speckle tracking echocardiography, ii) to assess two annuli dynamics and coupling behaviors as an integral, and iii) to detect the relation between two annuli and left ventricular ejection fraction (LVEF). A total of 74 healthy adults underwent transthoracic echocardiography. In the parasternal long-axis view, a number of points were extracted, including right coronary aortic annular, aortomitral fibrous junction, and posterior mitral annular points. The annuli excursion and AMA were measured using a speckle tracking-derived software during the cardiac cycle. During the isovolumic contraction and the isovolumic relaxation phase, annuli excursion and AMA remain stable for a short time. During the systole, annuli excursion increased sharply to the maximum, while AMA narrowed quickly to the minimum value. During the diastole, there are three patterns of decrease in annuli excursion and AMA expansion in different phases. The annuli excursion of three points correlates well with the LVEF (right coronary aortic annulus excursion, r=0.71, P<0.05; non-coronary aortic annulus excursion, r=0.70, P<0.05; posterior mitral annulus excursion, r=0.82, P<0.05). Moreover, there are positive correlations between annuli excursion and the variation of AMA (r=0.60, P<0.05). The annuli excursion and AMA have various regular patterns in healthy adults. The interactions of mitral and aortic annuli correlate with the left ventricular function. Our findings may have relevance to the evaluation of left ventricular function and presurgical planning of patients with valvular diseases. PMID:26693287

  5. Development of a Novel Output Value for Quantitative Assessment in Methylated DNA Immunoprecipitation-CpG Island Microarray Analysis

    PubMed Central

    Yamashita, Satoshi; Hosoya, Kosuke; Gyobu, Ken; Takeshima, Hideyuki; Ushijima, Toshikazu

    2009-01-01

    In DNA methylation microarray analysis, quantitative assessment of intermediate methylation levels in samples with various global methylation levels is still difficult. Here, specifically for methylated DNA immunoprecipitation-CpG island (CGI) microarray analysis, we developed a new output value. The signal log ratio reflected the global methylation levels, but had only moderate linear correlation (r = 0.72) with the fraction of DNA molecules immunoprecipitated. By multiplying the signal log ratio using a coefficient obtained from the probability value that took account of signals in neighbouring probes, its linearity was markedly improved (r = 0.94). The new output value, Me value, reflected the global methylation level, had a strong correlation also with the fraction of methylated CpG sites obtained by bisulphite sequencing (r = 0.88), and had an accuracy of 71.8 and 83.8% in detecting completely methylated and unmethylated CGIs. Analysis of gastric cancer cell lines using the Me value showed that methylation of CGIs in promoters and gene bodies was associated with low and high, respectively, gene expression. The degree of demethylation of promoter CGIs after 5-aza-2'-deoxycytidine treatment had no association with that of induction of gene expression. The Me value was considered to be useful for analysis of intermediate methylation levels of CGIs. PMID:19767598

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

    PubMed Central

    Valachis, Antonis; Nilsson, Cecilia

    2015-01-01

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

  7. Optimized Heart Sampling and Systematic Evaluation of Cardiac Therapies in Mouse Models of Ischemic Injury: Assessment of Cardiac Remodeling and Semi-Automated Quantification of Myocardial Infarct Size.

    PubMed

    Valente, Mariana; Arajo, Ana; Esteves, Tiago; Laundos, Tiago L; Freire, Ana G; Quelhas, Pedro; Pinto-do-, Perptua; Nascimento, Diana S

    2015-01-01

    Cardiac therapies are commonly tested preclinically in small-animal models of myocardial infarction. Following functional evaluation, post-mortem histological analysis is essential to assess morphological and molecular alterations underlying the effectiveness of treatment. However, non-methodical and inadequate sampling of the left ventricle often leads to misinterpretations and variability, making direct study comparisons unreliable. Protocols are provided for representative sampling of the ischemic mouse heart followed by morphometric analysis of the left ventricle. Extending the use of this sampling to other types of in situ analysis is also illustrated through the assessment of neovascularization and cellular engraftment in a cell-based therapy setting. This is of interest to the general cardiovascular research community as it details methods for standardization and simplification of histo-morphometric evaluation of emergent heart therapies. 2015 by John Wiley & Sons, Inc. PMID:26629776

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

    NASA Astrophysics Data System (ADS)

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

    2015-05-01

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

  9. Technical assessment of whole body angiography and cardiac function within a single MRI examination

    PubMed Central

    Gandy, S.J.; Lambert, M.; Belch, J.J.F.; Cavin, I.D.; Crowe, E.; Littleford, R.; Macfarlane, J.A.; Matthew, S.Z.; Martin, P.; Nicholas, R.S.; Struthers, A.D.; Sullivan, F.; Waugh, S.A.; White, R.D.; Weir-McCall, J.R.; Houston, J.G.

    2015-01-01

    Aim To evaluate a combined protocol for simultaneous cardiac MRI (CMR) and contrast-enhanced (CE) whole-body MR angiography (WB-MRA) techniques within a single examination. Materials and methods Asymptomatic volunteers (n=48) with low-moderate risk of cardiovascular disease (CVD) were recruited. The protocol was divided into four sections: (1) CMR of left ventricle (LV) structure and function; (2) CE-MRA of the head, neck, and thorax followed by the distal lower limbs; (3) CMR LV late gadolinium enhancement assessment; and (4) CE-MRA of the abdomen and pelvis followed by the proximal lower limbs. Multiple observers undertook the image analysis. Results For CMR, the mean ejection fraction (EF) was 67.34.8% and mean left ventricular mass (LVM) was 100.322.8 g. The intra-observer repeatability for EF ranged from 2.14.7% and from 912g for LVM. Interobserver repeatability was 8.1% for EF and 19.1g for LVM. No LV delayed myocardial enhancement was observed. For WB-MRA, some degree of luminal narrowing or stenosis was seen at 3.6% of the vessel segments (involving n=29 of 48 volunteers) and interobserver radiological opinion was consistent in 96.7% of 1488 vessel segments assessed. Conclusion Combined assessment of WB-MRA and CMR can be undertaken within a single examination on a clinical MRI system. The associated analysis techniques are repeatable and may be suitable for larger-scale cardiovascular MRI studies. PMID:25791202

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

    PubMed

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

    2013-11-01

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

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

    PubMed Central

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

    2015-01-01

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

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

    SciTech Connect

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

    2012-12-01

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

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

    PubMed Central

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

    2015-01-01

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

  14. Traditional and novel methods to assess and prevent chemotherapy-related cardiac dysfunction noninvasively.

    PubMed

    Schwartz, Ronald G; Jain, Diwakar; Storozynsky, Eugene

    2013-06-01

    The field of cardio-oncology is challenged to address an ever greater spectrum of cardiotoxicity associated with combination chemotherapy, greater dose intensity, extremes of age, and enhanced patient survival which exposes more protracted risk of developing congestive heart failure (CHF). Recent reports of chemotherapy-induced hypertension as a common adverse effect of angiogenesis inhibitors and immunosuppressants clarify the need for routine blood pressure (BP) monitoring and guideline-based management of hypertension as an integral strategy to preserve LV function. Serial monitoring of radionuclide left ventricular ejection fraction (LVEF) in adults and echocardiography in children continues to provide outcome based, cost-effective prevention of CHF in high risk patients receiving chemotherapy. To optimize treatment and monitoring strategies to eliminate late-onset LV dysfunction and CHF, traditional and novel candidate methods for assessment of chemotherapy-induced LV dysfunction are reviewed. These include serial assessment of LV volume indices by gated SPECT ERNA and gated SPECT MPI, 3D echocardiography and contrast 2D echocardiography; longitudinal strain imaging, diastolic functional parameters, (123)I-MIBG, (111)In-Antimyosin antibody imaging, and (99m)Tc-Annexin V apoptosis imaging, biomarkers including troponins and BNP; genetic markers, and both functional and tissue characterization techniques with T1 weighted and T2 weighted images with cardiac magnetic resonance imaging (CMR). In our quest to optimize strategies for long-term cancer survival and prevention of CHF for patients receiving chemotherapy, rigorous modality and guideline-specific clinical outcome trials are required. A new multi-modality monitoring approach is proposed, which integrates evidence-based strengths of CMR, echocardiography, ERNA, biomarkers, and BP management for surveillance and validation of cardiotoxicity and prevention of clinical heart failure in patients receiving a broad spectrum of cancer therapies. PMID:23572315

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

    PubMed Central

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

    2014-01-01

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

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

    PubMed

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

    2014-11-01

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

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

    PubMed Central

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

    2012-01-01

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

  18. Echocardiographic assessment of cardiac morphology and function in mutant dwarf rats.

    PubMed

    Longobardi, S; Cittadini, A; Strmer, H; Katz, S E; Grossman, J D; Clark, R G; Morgan, J P; Douglas, P S

    2000-10-01

    Although the mutant dwarf rat has been proposed as a model of growth hormone (GH) deficiency, few studies have addressed its cardiovascular abnormalities. Therefore, the aim of the present study was to investigate cardiac structure and function in mutant dwarf rats in vivo before and after chronic GH administration, by means of transthoracic Doppler echocardiography. To this purpose, forty 90-day-old female dwarf rats were randomized to receive either GH treatment or placebo. Twenty age-and sex-matched Lewis rats (200-250 g) served as the control group. All rats underwent echocardiograms before receiving any drug and after 3 weeks of therapy. Echocardiographically detected left ventricular mass indexed to tibial length was reduced by 41% in dwarf rats compared to the control group. Such relative cardiac atrophy was also evident at the myocyte level, and was fully reversible after GH therapy. In contrast to the control group, dwarf rats also showed a reduction of left ventricular diastolic volumes normalized to tibial length and impaired cardiac performance as suggested by the reduction of cardiac index, abnormal stress-shortening relations, and a significant elevation of total peripheral vascular resistance. All these abnormalities were reversible upon GH therapy for 3 weeks. In conclusion, GH plays an important role in maintaining a normal cardiac structure and function. Since the observed changes are similar to those seen in GH-deficient men, the mutant dwarf rat represents a faithful animal model of GH deficiency. PMID:11042020

  19. Comprehensible Output?

    ERIC Educational Resources Information Center

    Krashen, Stephen

    1998-01-01

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

  20. Assessment of thymic output in common variable immunodeficiency patients by evaluation of T cell receptor excision circles

    PubMed Central

    GUAZZI, V; AIUTI, F; MEZZAROMA, I; MAZZETTA, F; ANDOLFI, G; Mortellaro, A; Pierdominici, M; FANTINI, R; MARZIALI, M; AIUTI, A

    2002-01-01

    Common variable immunodeficiency (CVID) is a heterogeneous syndrome characterized by repeated infections and hypogammaglobulinaemia. Additionally, T-cell abnormalities including lymphopenia, decreased proliferation to mitogens and antigens, and the reduced production and expression of cytokines, have also been observed. In this study we have investigated the expression of naive, memory and activation markers in T-cell subpopulations in 17 CVID patients in comparison to age-matched normal controls. The numbers of CD4+ T cells, including CD45RA+CD62L+ and, to a lesser extent, CD45RA?CD62L+/RA+CD62L? were significantly reduced in patients, whereas CD8+ T cells were within normal range. In contrast, HLA-DR+ cells were increased both in CD4+ and CD8+ T cells. To assess the thymic output, we analysed the presence of T-cell receptor excision circles (TRECs) in CD4+ and CD8+ T cells by quantitative PCR. TRECs were decreased significantly in patients and the rate of TREC loss was higher with increasing age. TRECs correlated with naive CD4+ T cells, whereas there was an inverse relationship between TRECs and CD8+HLA?DR+ and CD8+CD45RA?CD62L+/RA+CD62L? T cells. Our results suggest the presence of a defect in the naive T cell compartment with origin at the thymic level in CVID, and indicate that TREC may be a useful marker to monitor thymic function in this primary immunodeficiency. PMID:12165093

  1. [Cardiovascular assessment and management prior to non-cardiac surgery : Comment on the new 2014 ESC/ESA guidelines].

    PubMed

    Kehmeier, E S; Schulze, V T

    2015-12-01

    In 2014 the European Society of Cardiology (ESC) and the European Society of Anaesthesiology (ESA) published an update of the guidelines on "non-cardiac surgery: cardiovascular assessment and management". Epidemiological data underline the relevance of these guidelines: a total of 5.7 million surgical procedures are performed per year in patients with increased cardiac risk and approximately 167,000 cardiac complications occur per year in Europe of which 19,000 are life-threatening. This new version of the guidelines highlights the patient characteristics, such as functional capacity and comorbidities and procedure-specific aspects for perioperative risk stratification. Decision-making for preoperative stress tests and coronary angiography has been simplified, procedure-specific risks have been revised and the role of multidisciplinary teamwork for high risk procedures is emphasized. A standardized stepwise approach on how to stratify patient-specific and procedure-associated risks has been established. For the first time, the guidelines recommend perioperative regimens on dual antiplatelet therapy and the new oral anticoagulants (NOAC). PMID:26612057

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

    PubMed Central

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

    2016-01-01

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

  3. Effective top-down LC/MS+ method for assessing actin isoforms as a potential cardiac disease marker.

    PubMed

    Chen, Yi-Chen; Ayaz-Guner, Serife; Peng, Ying; Lane, Nicole M; Locher, Matthew R; Kohmoto, Takushi; Larsson, Lars; Moss, Richard L; Ge, Ying

    2015-08-18

    Actin is the major component of the cytoskeleton, playing an essential role in the structure and motility of both muscle and nonmuscle cells. It is highly conserved and encoded by a multigene family. ?-Cardiac actin (?CAA) and ?-skeletal actin (?SKA), encoded by two different genes, are the primary actin isoforms expressed in striated muscles. The relative expression levels of ?SKA and ?CAA have been shown to vary between species and under pathological conditions. In particular, an increased ?SKA expression is believed to be a programmed response of a diseased heart. Therefore, it is essential to quantify the relative expression of ?SKA and ?CAA, which remains challenging due to the high degree of sequence similarity between these isoforms (98.9%). Herein, we developed a top-down liquid chromatography/mass spectrometry-based ("LC/MS+") method for the rapid purification and comprehensive analysis of ?-actin extracted from muscle tissues. We thoroughly investigated all of the actin isoforms in healthy human cardiac and skeletal muscles. We found that ?SKA is the only isoform expressed in skeletal muscle, whereas ?CAA and ?SKA are coexpressed in cardiac muscle. We then applied our method to quantify the ?-actin isoforms in human healthy hearts and failing hearts with dilated cardiomyopathy (DCM). We found that ?SKA is augmented in DCM compared with healthy controls, 43.1 0.9% versus 23.7 1.7%, respectively. As demonstrated, top-down LC/MS+ provides an effective and comprehensive method for the purification, quantification, and characterization of ?-actin isoforms, enabling assessment of their clinical potential as cardiac disease markers. PMID:26189812

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

    PubMed

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

    2015-01-01

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

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed

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

    2002-07-01

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

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

    SciTech Connect

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

    1990-01-01

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

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

    NASA Technical Reports Server (NTRS)

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

    2001-01-01

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

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed

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

    2015-03-01

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

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

    PubMed

    Sugisaki, Norihide; Okada, Junichi; Kanehisa, Hiroaki

    2013-01-01

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

  12. [Treatment of cardiac insufficiency in the acute stage of cardiac infarct].

    PubMed

    Popnikolov, S

    1979-01-01

    The studies on Strophantin effect upon the hemodynamics in the acute stage of cardiac infarction has revealed that it elevates the pressure in pulmonary artery and reduces the cardiac output, in certain cases deteriorating the patient's state. Furanthril and Droperidol reduce the cardiac output but at the same time diminish the pressure in the pulmonary artery and reduce the pulmonary resistance, thus having a favourable effect on the patient's state. Proceeding from the results obtained, a treatment scheme, including Furanthril, Droperidol and Strophantin, is recommended for the cardiac insufficiency treatment in the acute stage of cardiac infarction depending on the disease onset and the degree of cardiac insufficiency manifested. PMID:475892

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

    NASA Astrophysics Data System (ADS)

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

    2013-11-01

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

  14. Coronary artery vasculitis: assessment with cardiac multi-detector computed tomography.

    PubMed

    Jeon, Chang Ho; Kim, Yeo Koon; Chun, Eun Ju; Kim, Jeong A; Yong, Hwan Seok; Doo, Kyung Won; Choi, Sang Il

    2015-06-01

    Coronary artery vasculitis is rare and comprises an array of inflammatory diseases. It often results in severe and life-threatening complications, including coronary artery aneurysm, coronary artery stenosis, intraluminal thrombosis, and microcirculation abnormalities. These may occur at a young age and are often silent in the early phases. Invasive coronary angiography is the gold standard for diagnosing coronary artery disease (CAD); however, multi-detector computed tomography (MDCT) is now widely regarded as a powerful non-invasive tool for the detection of CAD. It is important for clinicians to recognize the various CT findings associated with coronary artery vasculitis in order to promote accurate diagnosis and proper patient management. The purpose of this article is to present an overview of the conditions associated with coronary artery vasculitis, with an emphasis on etiology and cardiac MDCT diagnosis of CAD. Cardiac MDCT is clinically useful and can provide information for the accurate diagnosis and treatment of coronary vasculitis. PMID:25841665

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

    PubMed Central

    Sidebotham, David

    2012-01-01

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

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

    NASA Technical Reports Server (NTRS)

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

    2000-01-01

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

  17. Age-related normal structural and functional ventricular values in cardiac function assessed by magnetic resonance

    PubMed Central

    2013-01-01

    Background The heart is subject to structural and functional changes with advancing age. However, the magnitude of cardiac age-dependent transformation has not been conclusively elucidated. Methods This retrospective cardiac magnetic resonance (CMR) study included 183 subjects with normal structural and functional ventricular values. End systolic volume (ESV), end diastolic volume (EDV), and ejection fraction (EF) were obtained from the left and the right ventricle in breath-hold cine CMR. Patients were classified into four age groups (2029, 3049, 5069, and ?70 years) and cardiac measurements were compared using Pearsons rank correlation over the four different groups. Results With advanced age a slight but significant decrease in ESV (r=?0.41 for both ventricles, P<0.001) and EDV (r=?0.39 for left ventricle, r=?0.35 for right ventricle, P<0.001) were observed associated with a significant increase in left (r=0.28, P<0.001) and right (r=0.27, P<0.01) ventricular EF reaching a maximal increase in EF of +8.4% (P<0.001) for the left and +6.1% (P<0.01) for the right ventricle in the oldest compared to the youngest patient group. Left ventricular myocardial mass significantly decreased over the four different age groups (P<0.05). Conclusions The aging process is associated with significant changes in left and right ventricular EF, ESV and EDV in subjects with no cardiac functional and structural abnormalities. These findings underline the importance of using age adapted values as standard of reference when evaluating CMR studies. PMID:23391039

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

    PubMed Central

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

    2014-01-01

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

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

    NASA Astrophysics Data System (ADS)

    Takahashi, Hiroki; Hasegawa, Hideyuki; Kanai, Hiroshi

    2015-07-01

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

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

    PubMed

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

    2016-04-01

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

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

    PubMed Central

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

    2008-01-01

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

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

    PubMed Central

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

    2013-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2015-01-01

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

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

    SciTech Connect

    Demos, S G; Sharareh, S

    2008-03-20

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

  5. A textile-based wearable system for the prolonged assessment of cardiac mechanics in daily life.

    PubMed

    Di Rienzo, Marco; Vaini, Emanuele; Castiglioni, Paolo; Lombardi, Prospero; Meriggi, Paolo; Rizzo, Francesco

    2014-01-01

    Seismocardiogram, SCG, can be detected over the 24 hours in ambulant subjects by a textile-based wearable system together with the electrocardiogram, ECG and respiration. In this pilot study we explored the possibility to derive 24 h profiles of cardiac time intervals, i.e. indexes of heart mechanical function, from the SCG recordings performed in daily life conditions by the above wearable system. Two healthy subjects were recruited for the study. They worn the system for 24 hours during a working day. From each recording, every 30 minutes the following parameters were derived from the ECG and SCG signals: RR interval, RRI, Pre-Ejection Period, PEP, Isovolumic Contraction Time, ICT, Left Ventricular Ejection Time, LVET, Isovolumic Relaxation Time, IRT. From the analysis it appears that 1) all parameters are characterized by a coefficient of variation in the same order of magnitude, and 2) 24 h LVET time profiles mirrors the long term RRI behavior. Common trends in PEP and ICT profiles were observed in one subject. This study indicates that indexes of cardiac mechanics can be derived from SCG recordings performed over the 24 hours. The obtained positive results encourage further studies to refine this methodology and confirm the present findings. PMID:25571581

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

    PubMed

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

    2016-02-01

    Accelerated in vitro biostability studies are useful for making relativistic comparisons between materials. However, no in vitro study can completely replicate the complex biochemical and biomechanical environment that a material experiences in the human body. To overcome this limitation, three insulation materials [Optim insulation (OPT), Pellethane 55D (P55D), and silicone elastomer] from cardiac leads that were clinically implanted for up to five years were characterized using visual inspection, SEM, ATR-FTIR, GPC, and tensile testing. Surface cracking was not observed in OPT or silicone samples. Shallow cracking was observed in 17/41 (41%) explanted P55D samples. ATR-FTIR indicated minor surface oxidation in some OPT and P55D samples. OPT molecular weight decreased modestly (?20%) at 2-3 years before stabilizing at 4-5 years. OPT tensile strength decreased modestly (?25%) at 2-3 years before stabilizing at 4-5 years. OPT elongation at 4-5 years was unchanged from controls. P55D had no significant changes in molecular weight or tensile properties. Overall, results for OPT and P55D were consistent with and limited to cosmetic surface oxidation. Silicone demonstrated excellent biostability with no identifiable degradation. This study of explanted cardiac leads revealed that OPT, P55D, and silicone elastomer demonstrate similar and excellent biostability through five years of implantation in human patients. 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 411-421, 2016. PMID:25891020

  7. Assessment of total cardiac repolarizations spatial distribution among patients with aortic sclerosis

    PubMed Central

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

    2015-01-01

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

  8. Devices used in cardiac arrest.

    PubMed

    Brooks, Steven C; Toma, Alina; Hsu, Jonathan

    2012-02-01

    Even the best conventional manual cardiopulmonary resuscitation (CPR) is highly inefficient, producing only a fraction of normal cardiac output. Over the past several decades, many therapeutic devices have been designed to improve on conventional CPR during cardiac arrest and increase the probability of survival. This article reviews several adjuncts and mechanical alternatives to conventional CPR for use during cardiac arrest. Recent clinical studies comparing conventional resuscitation techniques with the use of devices during cardiac arrest are reviewed, with a focus on clinical implications and directions for future research. PMID:22107983

  9. The Effects That Cardiac Motion has on Coronary Hemodynamics and Catheter Trackability Forces for the Treatment of Coronary Artery Disease: An In Vitro Assessment.

    PubMed

    Morris, Liam; Fahy, Paul; Stefanov, Florian; Finn, Ronan

    2015-12-01

    The coronary arterial tree experiences large displacements due to the contraction and expansion of the cardiac muscle and may influence coronary haemodynamics and stent placement. The accurate measurement of catheter trackability forces within physiological relevant test systems is required for optimum catheter design. The effects of cardiac motion on coronary flowrates, pressure drops, and stent delivery has not been previously experimentally assessed. A cardiac simulator was designed and manufactured which replicates physiological coronary flowrates and cardiac motion within a patient-specific geometry. A motorized delivery system delivered a commercially available coronary stent system and monitored the trackability forces along three phantom patient-specific thin walled compliant coronary vessels supported by a dynamic cardiac phantom model. Pressure drop variation is more sensitive to cardiac motion than outlet flowrates. Maximum pressure drops varied from 7 to 49mmHg for a stenosis % area reduction of 56 to 90%. There was a strong positive linear correlation of cumulative trackability force with the cumulative curvature. The maximum trackability forces and curvature ranged from 0.24 to 0.87N and 0.06 to 0.22mm(-1) respectively for all three vessels. There were maximum and average percentage differences in trackability forces of (23-49%) and (1.9-5.2%) respectively when comparing a static pressure case with the inclusion of pulsatile flow and cardiac motion. Cardiac motion with pulsatile flow significantly altered (p value <0.001) the trackability forces along the delivery pathways with high local percentage variations and pressure drop measurements. PMID:26577477

  10. Assessment of nonpenetrating captive bolt stunning followed by electrical induction of cardiac arrest in veal calves.

    PubMed

    Bartz, B; Collins, M; Stoddard, G; Appleton, A; Livingood, R; Sobcynski, H; Vogel, K D

    2015-09-01

    The purpose of this study was to evaluate the impact of nonpenetrating captive bolt stunning followed by electrical induction of cardiac arrest on veal calf welfare, veal quality, and blood yield. Ninety calves from the same farm were randomly assigned to 1 of 2 treatment groups in a balanced unpaired comparison design. The first treatment group (the "head-only" method-application of the pneumatic nonpenetrating stun to the frontal plate of the skull at the intersection of 2 imaginary lines extending from the lateral canthus to the opposite poll [CONTROL]) was stunned with a nonpenetrating captive bolt gun ( = 45). The second group ( = 45) was stunned with a nonpenetrating captive bolt gun followed by secondary electrical induction of cardiac arrest (the "head/heart" method-initial application of the pneumatic nonpenetrating captive bolt stun followed by 1 s application of an electrical stun to the ventral region of the ribcage directly caudal to the junction of the humerus and scapula while the stunned calf was in lateral recumbence [HEAD/HEART]). Stunning efficacy was the indicator of animal welfare used in this study. All calves were instantly rendered insensible by the initial stun and did not display common indicators of return to consciousness. For meat quality evaluation, all samples were collected from the 12th rib region of the longissimus thoracis. Meat samples were evaluated for color, drip loss, ultimate pH, cook loss, and Warner-Bratzler shear force. The L* values (measure of meat color lightness) were darker ( < 0.05) in the HEAD/HEART group (45.08 ± 0.72) than the CONTROL group (47.10 ± 0.72). There were no differences ( > 0.05) observed in a* (redness) and b* (yellowness) values between treatments. No differences ( > 0.05) were observed in drip loss, ultimate pH, cook loss, and Warner-Bratzler shear force. The blood yield from the CONTROL group (7,217.9 ± 143.5 g) was greater ( < 0.05) than that from the HEAD/HEART group (6,656.4 ± 143.5 g). Overall, the data indicated no difference between the CONTROL and HEAD/HEART groups with regard to animal welfare because the initial stun was effective in all calves. However, longissimus thoracis L* and blood yield were negatively impacted by the HEAD/HEART method. The data in this study suggest that secondary induction of cardiac arrest is not necessary with effective nonpenetrating captive bolt stunning in veal calves. PMID:26440354

  11. Formation and Malformation of Cardiac Trabeculae: Biological Basis, Clinical Significance, and Special Yield of Magnetic Resonance Imaging in Assessment.

    PubMed

    Captur, Gabriella; Syrris, Petros; Obianyo, Chinwe; Limongelli, Giuseppe; Moon, James C

    2015-11-01

    Adult and pediatric cardiologists are familiar with variation in cardiac trabeculation. Abnormal trabeculation is a key feature of left ventricular noncompaction, but it is also common in congenital heart diseases and in cardiomyopathies (dilated and hypertrophied). Trabeculae might be a measurable phenotypic marker that will allow insights into how cardiomyopathy and congenital heart disease arise and develop. This will require the linking together of clinical and preclinical information (such as embryology and genetics), with new analysis methods for trabecular quantitation. In adult cardiology several promising quantitative methods have been developed for echocardiography, computed tomography, and cardiovascular magnetic resonance, and earlier cross-sectional caliper approaches have now been refined to permit more advanced assessment. Adaptation of these methods for use in developmental biology might inform on better ways to measure and track trabecular morphology in model organisms. PMID:26440509

  12. The Role of Magnetic Resonance Imaging and Cardiac Computed Tomography in the Assessment of Left Atrial Anatomy, Size, and Function

    PubMed Central

    Kuchynka, Petr; Podzimkova, Jana; Masek, Martin; Lambert, Lukas; Cerny, Vladimir; Danek, Barbara; Palecek, Tomas

    2015-01-01

    In the last decade, there has been increasing evidence that comprehensive evaluation of the left atrium is of utmost importance. Numerous studies have clearly demonstrated the prognostic value of left atrial volume for long-term outcome. Furthermore, advances in catheter ablation procedures used for the treatment of drug-refractory atrial fibrillation require the need for detailed knowledge of left atrial and pulmonary venous morphology as well of atrial wall characteristics. This review article discusses the role of cardiac magnetic resonance and computed tomography in assessment of left atrial size, its normal and abnormal morphology, and function. Special interest is paid to the utility of these rapidly involving noninvasive imaging methods before and after atrial fibrillation ablation. PMID:26221583

  13. Safety assessment and biodistribution of povidone as a coating material for cardiac pacing leads

    SciTech Connect

    Jay, M.; Digenis, G.A.

    1983-01-01

    Cardiac pacing leads coated with povidone-(/sup 131/I) were implanted in dogs and the leaching of radioactivity from the leads was monitored by external scintigraphy. The activity which had dissipated from the pacing leads was not as (/sup 131/I)-iodide, but as povidone-(/sup 131/I). Only 50% (mean) of the activity remained on the pacing leads after two weeks while a significant amount of radioactivity was eliminated via urine and feces. The liver was a major site of accumulation of retained activity which had leached off the pacing leads. There was no evidence of large pieces of povidone-(/sup 131/I) in the lungs of the dogs, all of which appeared healthy at the time of sacrifice. The results of this study support the conclusions of a long-term study indicating that povidone is a safe and suitable coating material for pacing leads.

  14. On-chip assessment of human primary cardiac fibroblasts proliferative responses to uniaxial cyclic mechanical strain.

    PubMed

    Ugolini, Giovanni Stefano; Rasponi, Marco; Pavesi, Andrea; Santoro, Rosaria; Kamm, Roger; Fiore, Gianfranco Beniamino; Pesce, Maurizio; Soncini, Monica

    2016-04-01

    Cardiac cell function is substantially influenced by the nature and intensity of the mechanical loads the cells experience. Cardiac fibroblasts (CFs) are primarily involved in myocardial tissue remodeling: at the onset of specific pathological conditions, CFs activate, proliferate, differentiate, and critically alter the amount of myocardial extra-cellular matrix with important consequences for myocardial functioning. While cyclic mechanical strain has been shown to increase matrix synthesis of CFs in vitro, the role of mechanical cues in CFs proliferation is unclear. We here developed a multi-chamber cell straining microdevice for cell cultures under uniform, uniaxial cyclic strain. After careful characterization of the strain field, we extracted human heart-derived CFs and performed cyclic strain experiments. We subjected cells to 2% or 8% cyclic strain for 24 h or 72 h, using immunofluorescence to investigate markers of cell morphology, cell proliferation (Ki67, EdU, phospho-Histone-H3) and subcellular localization of the mechanotransduction-associated transcription factor YAP. Cell morphology was affected by cyclic strain in terms of cell area, cell and nuclear shape and cellular alignment. We additionally observed a strain intensity-dependent control of cell growth: a significant proliferation increase occurred at 2% cyclic strain, while time-dependent effects took place upon 8% cyclic strain. The YAP-dependent mechano-transduction pathway was similarly activated in both strain conditions. These results demonstrate a differential effect of cyclic strain intensity on human CFs proliferation control and provide insights into the YAP-dependent mechano-sensing machinery of human CFs. Biotechnol. Bioeng. 2016;113: 859-869. © 2015 Wiley Periodicals, Inc. PMID:26444553

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

    ERIC Educational Resources Information Center

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

    2016-01-01

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

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

    ERIC Educational Resources Information Center

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

    2016-01-01

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

  17. Morphological and Volumetric Analysis of Left Atrial Appendage and Left Atrium: Cardiac Computed Tomography-Based Reproducibility Assessment

    PubMed Central

    Taina, Mikko; Korhonen, Miika; Haataja, Mika; Muuronen, Antti; Arponen, Otso; Hedman, Marja; Jkl, Pekka; Sipola, Petri; Mustonen, Pirjo; Vanninen, Ritva

    2014-01-01

    Objectives Left atrial appendage (LAA) dilatation and morphology may influence an individual's risk for intracardiac thrombi and ischemic stroke. LAA size and morphology can be evaluated using cardiac computed tomography (cCT). The present study evaluated the reproducibility of LAA volume and morphology assessments. Methods A total of 149 patients (47 females; mean age 60.910.6 years) with suspected cardioembolic stroke/transient ischemic attack underwent cCT. Image quality was rated based on four categories. Ten patients were selected from each image quality category (N?=?40) for volumetric reproducibility analysis by two individual readers. LAA and left atrium (LA) volume were measured in both two-chamber (2CV) and transversal view (TV) orientation. Intertechnique reproducibility was assessed between 2CV and TV (200 measurement pairs). LAA morphology (A?=?Cactus, B?=?ChickenWing, C?=?WindSock, D?=?CauliFlower), LAA opening height, number of LAA lobes, trabeculation, and orientation of the LAA tip was analysed in all study subjects by three individual readers (447 interobserver measurement pairs). The reproducibility of volume measurements was assessed by intra-class correlation (ICC) and the reproducibility of LAA morphology assessments by Cohen's kappa. Results The intra-observer and interobserver reproducibility of LAA and LA volume measurements was excellent (ICCs>0.9). The LAA (ICC?=?0.954) and LA (ICC?=?0.945) volume measurements were comparable between 2CV and TV. Morphological classification (??=?0.24) and assessments of LAA opening height (??=?0.1), number of LAA lobes (??=?0.16), trabeculation (??=?0.15), and orientation of the LAA tip (??=?0.37) was only slightly to fairly reproducible. Conclusions LA and LAA volume measurements on cCT provide excellent reproducibility, whereas visual assessment of LAA morphological features is challenging and results in unsatisfactory agreement between readers. PMID:24988467

  18. Quantifying the total environmental impacts of an industrial symbiosis - a comparison of process-, hybrid and input-output life cycle assessment.

    PubMed

    Mattila, Tuomas J; Pakarinen, Suvi; Sokka, Laura

    2010-06-01

    Industrial symbiosis, representing resource sharing and byproduct use among colocated firms, is a key concept of industrial ecology. Local co-operation in industrial symbioses can reduce raw material use and waste disposal, but material and energy flows extending outside symbiosis boundaries can cause considerable environmental impacts. These external impacts are often ignored in industrial symbiosis studies. In this study, we compared process, hybrid and input-output life cycle assessment (LCA) approaches in quantifying the overall environmental impacts of a forest industrial symbiosis, situated in Kymenlaakso, Finland. Conclusions from an earlier process-LCA were strengthened by the use of hybrid-LCA as local emissions were found to cause less than half of the global impacts. In some impact categories, the whole impact was caused by supply chain emissions (land use, metal depletion and ozone depletion). The cutoff in process-LCA was found to be less than 25%, except in metal depletion and terrestrial ecotoxicity. Input-output LCA approximated hybrid-LCA results well in most impact categories, but seriously underestimated land use and overestimated terrestrial ecotoxicity. Based on the results we conclude, that input-output based LCA can be used to analyze the global impacts of an industrial symbiosis, but a careful interpretation of the results is necessary in order to understand the influence of aggregation and allocation. PMID:20408541

  19. Late cardiac sodium current can be assessed using automated patch-clamp

    PubMed Central

    Gawali, Vaibhavkumar; Todt, Hannes; Knott, Thomas; Scheel, Olaf; Abriel, Hugues

    2014-01-01

    The cardiac late Na + current is generated by a small fraction of voltage-dependent Na + channels that undergo a conformational change to a burst-gating mode, with repeated openings and closures during the action potential (AP) plateau. Its magnitude can be augmented by inactivation-defective mutations, myocardial ischemia, or prolonged exposure to chemical compounds leading to drug-induced (di)-long QT syndrome, and results in an increased susceptibility to cardiac arrhythmias. Using CytoPatch 2 automated patch-clamp equipment, we performed whole-cell recordings in HEK293 cells stably expressing human Nav1.5, and measured the late Na + component as average current over the last 100 ms of 300 ms depolarizing pulses to -10 mV from a holding potential of -100 mV, with a repetition frequency of 0.33 Hz. Averaged values in different steady-state experimental conditions were further corrected by the subtraction of current average during the application of tetrodotoxin (TTX) 30 ?M. We show that ranolazine at 10 and 30 ?M in 3 min applications reduced the late Na + current to 75.0 2.7% (mean SEM, n = 17) and 58.4 3.5% ( n = 18) of initial levels, respectively, while a 5 min application of veratridine 1 ?M resulted in a reversible current increase to 269.1 16.1% ( n = 28) of initial values. Using fluctuation analysis, we observed that ranolazine 30 ?M decreased mean open probability p from 0.6 to 0.38 without modifying the number of active channels n, while veratridine 1 ?M increased n 2.5-fold without changing p. In human iPSC-derived cardiomyocytes, veratridine 1 ?M reversibly increased APD90 2.12 0.41-fold (mean SEM, n = 6). This effect is attributable to inactivation removal in Nav1.5 channels, since significant inhibitory effects on hERG current were detected at higher concentrations in hERG-expressing HEK293 cells, with a 28.9 6.0% inhibition (mean SD, n = 10) with 50 ?M veratridine. PMID:25383189

  20. Predictive Value of Assessing Diastolic Strain Rate on Survival in Cardiac Amyloidosis Patients with Preserved Ejection Fraction

    PubMed Central

    Strk, Stefan; Herrmann, Sebastian; Kramer, Bastian; Cikes, Maja; Gaudron, Philipp Daniel; Knop, Stefan; Ertl, Georg; Bijnens, Bart; Weidemann, Frank

    2014-01-01

    Objectives 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%). Background 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. Methods Conventional echocardiography and STI were performed in 41 CA patients with preserved LVEF (25 male; mean age 659 years). Global and segmental LSsys and LSRdias were obtained in six LV segments from apical 4-chamber views. Results Nineteen (46%) out of 41 CA patients died during a median of 16 months (quartiles 535 months) follow-up. Baseline mitral annular plane systolic excursion (MAPSE, 62 vs. 83 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] 1.173.26, P?=?0.010), global LSRdias (HR?=?7.30, 95% CI 2.0825.65, P?=?0.002), and E/LSRdias (HR?=?2.98, 95% CI 1.545.79, 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. Conclusions STI-derived early diastolic strain rate is a powerful independent predictor of survival in CA patients with preserved LVEF. PMID:25542015

  1. Ischemic injury of the liver in a porcine model of cardiac death assessed by in vivo microdialysis.

    PubMed

    Yi, De-Hui; Liu, Hao; Chen, Ying; Li, Hong; Xu, Tie; Liu, Yong-Feng

    2014-10-01

    This study aims to evaluate the ischemic injury of the liver in a porcine model of cardiac death assessed by in vivo microdialysis. A porcine model of cardiac death was established by the suffocation method. Metabolic indicators were monitored using the microdialysis technique during warm ischemia time (WIT) and cold ischemia time (CIT). Pathological changes in ischemic-injured livers were observed by haematoxylin-eosin staining. The predictive values of biochemical parameters regarding the liver donor were evaluated by receiver operating characteristic curve analysis. All statistical analyses were conducted using the SPSS 18.0 software (SPSS Inc, Chicago, Illinois, USA). The degree of warm ischemic injury of the livers increased with prolonged WIT. Serum glucose, glycerol, pyruvate, lactic acid levels and lactate-to-pyruvate (L/P) ratio increased gradually during WIT. Results from Pearson correlation analyses indicated that serum lactate level and L/P ratio were positively associated with the degree of warm ischemic injury of the livers. The degree of cold ischemic injury of the livers gradually increased after 12 h CIT. Serum glucose, lactic acid and L/P ratio achieved a peak after 6-8 h of CIT, but gradually decreased with prolonged CIT. The peak of glycerol occurred after 8 h of CIT, while no changes were found with prolonged CIT. Serum pyruvate level exhibited an increasing trend after 12 h CIT. Our results confirmed that serum glucose and lactate levels were negatively correlated with cold ischemic injury of the liver. However, serum glycerol and pyruvate levels showed positive correlations with cold ischemic injury of the liver. The liver donor was unavailable after 30 min WIT and 24 h CIT. The cut-off value of serum lactate level for warm ischemic injury of the livers was 2.374 with a sensitivity (Sen) of 90 % and specificity (Spe) of 95 %; while the L/P radio was 0.026 (Sen = 80 %, Spe = 83 %). In addition, the cut-off values of serum glucose, lactate, glycerol and pyruvate levels for cold ischemic injury of the livers were 0.339 (Sen = 100 %, Spe = 77 %), 1.172 (Sen = 100 %, Spe = 61 %), 56.359 (Sen = 100 %, Spe = 65 %) and 0.020 (Sen = 100 %, Spe = 67 %), respectively. Our findings provide empirical evidences that serum glucose, lactate levels and L/P ratio may be good indicators for the degree of warm ischemic injury of the livers after cardiac death; while serum glucose, lactate, glycerol and pyruvate levels may be important in predicting cold ischemic injury. PMID:25167853

  2. Absorbed dose assessment of cardiac and other tissues around the cardiovascular system in brachytherapy with 90Sr/90Y source by Monte Carlo simulation.

    PubMed

    Saghamanesh, S; Karimian, A; Abdi, M

    2011-09-01

    Cardiac disease is one of the most important causes of death in the world. Coronary artery stenosis is a very common cardiac disease. Intravascular brachytherapy (IVBT) is one of the radiotherapy methods which have been used recently in coronary artery radiation therapy for the treatment of restenosis. (90)Sr/(90)Y, a beta-emitting source, is a proper option for cardiovascular brachytherapy. In this research, a Monte Carlo simulation was done to calculate dosimetry parameters and effective equivalent doses to the heart and its surrounding tissues during IVBT. The results of this study were compared with the published experimental data and other simulations performed by different programs but with the same source of radiation. A very good agreement was found between results of this work and the published data. An assessment of the risk for cardiac and other sensitive soft tissues surrounding the treated vessel during (90)Sr/(90)Y IVBT was also performed in the study. PMID:21831866

  3. Calibration of Kodak EDR2 film for patient skin dose assessment in cardiac catheterization procedures

    NASA Astrophysics Data System (ADS)

    Morrell, Rachel E.; Rogers, Andy

    2004-12-01

    Kodak EDR2 film has been calibrated across the range of exposure conditions encountered in our cardiac catheterization laboratory. Its dose-response function has been successfully modelled, up to the saturation point of 1 Gy. The most important factor affecting film sensitivity is the use of beam filtration. Spectral filtration and kVp together account for a variation in dose per optical density of -10% to +25%, at 160 mGy. The use of a dynamic wedge filter may cause doses to be underestimated by up to 6%. The film is relatively insensitive to variations in batch, field size, exposure rate, time to processing and day-to-day fluctuations in processor performance. Overall uncertainty in the calibration is estimated to be -20% to +40%, at 160 mGy. However, the uncertainty increases at higher doses, as the curve saturates. Artefacts were seen on a number of films, due to faults in the light-proofing of the film packets.

  4. Thoracic aorta cardiac-cycle related dynamic changes assessed with a 256-slice CT scanner

    PubMed Central

    Carrascosa, Patricia; Capuay, Carlos; Deviggiano, Alejandro; Rodrguez-Granillo, Gastn A.; Sagarduy, Mara Ins; Cortines, Patricio; Carrascosa, Jorge; Parodi, Juan C.

    2013-01-01

    Objective The aim of our study was to demonstrate whether the dynamic changes previously documented at the ascending and abdominal aorta are replicated at the thoracic aorta. Methods and results A consecutive series of thirty patients referred to our institution to undergo CT angiography of the thoracic aorta (CTA) constituted the study population. Patients with diffuse aortic atherosclerosis were excluded from the analysis. All studies were acquired with a 256-MDCT scanner and ECG-gating was performed in all cases. Two orthogonal imaging planes (maximal and minimal diameters) were obtained at three different levels of the descending thoracic aorta, using the distance from the left subclavian artery as proximal landmark: 10, 40, and 80 mm distance. The mean age was 58.915.7 years and 16 (53%) patients were male. Descending aorta measurements at 10, 40, and 80 mm distance from the left subclavian artery were all significantly larger within the systolic window (P<0.01 for all comparisons). Measurements of the maximal diameter were systematically larger than the minimal diameters among all aortic positions including ungated, systolic, and diastolic measurements (P<0.05 for all comparisons). Conclusions The main finding of our pilot investigation was that the thoracic descending aorta undergoes significant conformational changes during the cardiac cycle, irrespective from the distance from the left subclavian artery. PMID:24282760

  5. Uterine Intravenous Leiomyomatosis with Cardiac Extension: Radiologic Assessment with Surgical and Pathologic Correlation

    PubMed Central

    Nakai, Go; Maeda, Kazuya; Yamamoto, Kazuhiro; Yamada, Takashi; Hirose, Yoshinobu; Terai, Yoshito; Ohmichi, Masahide; Katsumata, Takahiro; Narumi, Yoshifumi

    2015-01-01

    We present the computed tomography (CT) and magnetic resonance (MR) imaging findings of a 71-year-old woman with a cardiac extension of intravenous leiomyoma (IVL) that arose from the uterus, extended to the inferior vena cava (IVC), and reached the right ventricle through the right ovarian vein. Radiologic-pathologic correlation showed that the intravascular cord-like mass originating from the IVC and extending to the right ventricle was composed of degenerated smooth muscle cells with a number of large vessels that were regarded as arteries; moreover, the arteries within the cord-like mass appeared to be looping internally. Given the disappearance of the right ovarian venous wall around the IVL pathologically, extracting the tumor from the ovarian vein during an operation is considered to be impossible retrospectively. Also it was difficult to identify even the intravenous extension of the uterine leiomyoma histopathologically. Therefore, contrast-enhanced CT, in particular arterial phase imaging, provided important information that revealed the mass, range, and path of the lesion, ensuring that an appropriate operative plan could be drawn up and the tumor completely excised. PMID:26236515

  6. Application of Lidar Data in the Assessment of Observed and Model Output Temperature Soundings During the Pacific 2001 Field Study.

    NASA Astrophysics Data System (ADS)

    Strawbridge, K. B.; Snyder, B. J.

    2002-12-01

    Surface and airborne lidar, along with upper air soundings and model derived soundings were examined over the course of the Pacific 2001 Air Quality Field Study. The general region of interest in this report is the Georgia Basin with a focus on the Lower Fraser Valley of British Columbia. Data included the following: RASCAL (Rapid Acquisition SCanning Aerosol Lidar), a surface-based scanning lidar facility at the Langley Lochiel site, operating close to 16 hours each day; AERIAL (AERosol Imaging Airborne Lidar), a simultaneous upward/downward airborne lidar system providing 9 flights during the field study; radiosondes, released 4 times daily from the Langley Poppy site; and once-daily 3.3 km resolution MC2 (Mesoscale Compressible Community weather prediction) model output. Methods of diagnosing mixing heights amongst the various datasets are outlined. The higher resolution lidar data provides a means of calibrating mixing heights from radiosondes and also allows a means of evaluating model derived soundings. Results show that in most cases there is good agreement amongst the various sources of data. This data is then used to demonstrate the variation of mixing height with sea breeze activity over the Lower Fraser Valley.

  7. A Novel Miniaturized Multimodal Bioreactor for Continuous In Situ Assessment of Bioartificial Cardiac Tissue During Stimulation and Maturation

    PubMed Central

    Kensah, George; Viering, Jrg; Schumann, Henning; Dahlmann, Julia; Meyer, Heiko; Skvorc, David; Br, Antonia; Akhyari, Payam; Heisterkamp, Alexander; Haverich, Axel; Martin, Ulrich

    2011-01-01

    Stem cell-based cardiac tissue engineering is a promising approach for regenerative therapy of the injured heart. At present, the small number of stem cell-derived cardiomyocytes that can be obtained using current culture and enrichment techniques represents one of the key limitations for the development of functional bioartificial cardiac tissue (BCT). We have addressed this problem by construction of a novel bioreactor with functional features of larger systems that enables the generation and in situ monitoring of miniaturized BCTs. BCTs were generated from rat cardiomyocytes to demonstrate advantages and usefulness of the bioreactor. Tissues showed spontaneous, synchronized contractions with cell orientation along the axis of strain. Cyclic stretch induced cardiomyocyte hypertrophy, demonstrated by a shift of myosin heavy chain expression from the alpha to beta isoform, together with elevated levels of atrial natriuretic factor. Stretch led to a moderate increase in systolic force (1.42??0.09?mN vs. 0.96??0.09?mN in controls), with significantly higher forces observed after ?-adrenergic stimulation with noradrenalin (2.54??0.11?mN). Combined mechanical and ?-adrenergic stimulation had no synergistic effect. This study demonstrates for the first time that mechanical stimulation and direct real-time contraction force measurement can be combined into a single multimodal bioreactor system, including electrical stimulation of excitable tissue, perfusion of the culture chamber, and the possibility of (fluorescence) microscopic assessment during continuous cultivation. Thus, this bioreactor represents a valuable tool for monitoring tissue development and, ultimately, the optimization of stem cell-based tissue replacement strategies in regenerative medicine. PMID:21142417

  8. A thorough QT study to assess the effects of tbo-filgrastim on cardiac repolarization in healthy subjects

    PubMed Central

    Adar, Liat; Avisar, Noa; Lammerich, Andreas; Kleiman, Robert B; Spiegelstein, Ofer

    2015-01-01

    Tbo-filgrastim is a recombinant human granulocyte colony-stimulating factor approved by the US Food and Drug Administration to reduce the duration of severe neutropenia in patients with nonmyeloid malignancies receiving myelosuppressive anticancer drugs associated with a clinically significant incidence of febrile neutropenia. We assessed the effect of tbo-filgrastim on cardiac conduction and repolarization in healthy subjects. A three-arm, parallel-group, active- and placebo-controlled, double-blind study randomized healthy adults to a single 5 ?g/kg intravenous tbo-filgrastim infusion, a single intravenous placebo infusion, or a single 400 mg moxifloxacin oral dose. The primary end point was placebo-corrected time-matched change from baseline in QT interval corrected using a QT individual correction (QTcI) method. Secondary end points included heart rate, PR interval, QRS duration, change in electrocardiogram patterns, correlation between QTcI change from baseline (milliseconds) and tbo-filgrastim serum concentrations, and safety variables. A total of 145 subjects were enrolled (50 tbo-filgrastim, 50 placebo, 45 moxifloxacin). Peak placebo-corrected change from baseline for QTcI with tbo-filgrastim was 3.5 milliseconds, with a two-sided 95% upper confidence interval of 7.2 milliseconds, demonstrating no signal for any tbo-filgrastim effect on QTc. Concentration-effect modeling showed no evidence of an effect of tbo-filgrastim on cardiac repolarization. Tbo-filgrastim produced no clinically significant changes in other electrocardiogram parameters. Tbo-filgrastim was well tolerated. PMID:26028962

  9. Protocol for the China PEACE (Patient-centered Evaluative Assessment of Cardiac Events) Million Persons Project pilot

    PubMed Central

    Lu, Jiapeng; Xuan, Si; Downing, Nicholas S; Wu, Chaoqun; Li, Li; Krumholz, Harlan M; Jiang, Lixin

    2016-01-01

    Introduction Collection of high-quality data from large populations is considered essential to generate knowledge that is critical to an era of precision medicine. Cardiovascular disease (CVD) is a leading cause of mortality in China and is a suitable focus of an initiative to discover factors that would improve our ability to assess and modify individual risk. Methods and analysis The pilot phase of China PEACE (Patient-centered Evaluative Assessment of Cardiac Events) Million Persons Project is being conducted during 2014–2015 in four provinces across China to demonstrate the feasibility of a population-based assessment. It is designed to screen 0.4 million community-dwelling residents aged 40–75 years with measurements of blood pressure, height and weight, a lipid blood test, and a questionnaire on cardiovascular-related health status. Participants identified at high risk of CVD receive further health assessments, including ECG, ultrasound scan, blood and urine analysis, and a questionnaire on lifestyle and medical history. Collection of blood and urine samples is used to establish a biobank. High-risk subjects are also counselled with suggestions regarding potential lifestyle changes. In addition, high-risk subjects are followed-up either in a return clinic visit or by telephone interview, with measurement of blood pressure, weight, ECG, and a questionnaire on survival status, hospitalisations and lifestyle. The first 0.1 million participants screened were used to conduct a preliminary analysis, with information on baseline characteristics, health-related behaviours, anthropometric variables, medical history, and prevalence of high-risk subjects. Ethics and dissemination The central ethics committee at the China National Center for Cardiovascular Disease (NCCD) approved the pilot. Written informed consent is obtained from all participants on entry into the project. Findings will be disseminated in future peer-reviewed papers and will inform strategies aimed at developing precise methods of assessing and modifying risk. Trial registration number NCT02536456. PMID:26729395

  10. Cardiac Assessment Risk Evaluation (Care Study) of African American College Women

    ERIC Educational Resources Information Center

    Brown, Sandra C.; Geiselman, Paula J.; Copeland, Amy L.; Gordon, Carol; Dudley, Mary; Manogin, Toni; Backstedt, Carol; Pourciau, Cathi; Ghebretatios, Ghenet

    2005-01-01

    Objective: To identify physiological and psychosocial variables of young African American women that may serve as a risk factor for heart disease and to assess their health promotion programme preferences. Method: A descriptive design was used to assess the cardiovascular risk factors of 100 African American women ages 18 to 40 years, enrolled in

  11. Cardiac Assessment Risk Evaluation (Care Study) of African American College Women

    ERIC Educational Resources Information Center

    Brown, Sandra C.; Geiselman, Paula J.; Copeland, Amy L.; Gordon, Carol; Dudley, Mary; Manogin, Toni; Backstedt, Carol; Pourciau, Cathi; Ghebretatios, Ghenet

    2005-01-01

    Objective: To identify physiological and psychosocial variables of young African American women that may serve as a risk factor for heart disease and to assess their health promotion programme preferences. Method: A descriptive design was used to assess the cardiovascular risk factors of 100 African American women ages 18 to 40 years, enrolled in…

  12. Cardiac Sarcoidosis

    MedlinePLUS

    ... Ventricular tachycardia often requires placement of an internal cardiac defibrillator (ICD). What do we do at National Jewish Health? We provide comprehensive cardiology evaluation and consultation and non-invasive cardiac testing. We evaluate and treat heart problems such ...

  13. ASSESSMENT OF MATHEMATICAL MODELS FOR STORM AND COMBINED SEWER MANAGEMENT. APPENDIX F: SELECTED COMPUTER INPUT AND OUTPUT

    EPA Science Inventory

    Mathematical models for the nonsteady simulation of urban runoff were evaluated to determine their suitability for the engineering assessment, planning, design and control of storm and combined sewerage systems. The models were evaluated on the basis of information published by t...

  14. Assessment of the role of the renin-angiotensin system in cardiac contractility utilizing the renin inhibitor remikiren.

    PubMed Central

    van Kats, J. P.; Sassen, L. M.; Danser, A. H.; Polak, M. P.; Soei, L. K.; Derkx, F. H.; Schalekamp, M. A.; Verdouw, P. D.

    1996-01-01

    1. The role of the renin-angiotensin system in the regulation of myocardial contractility is still debated. In order to investigate whether renin inhibition affects myocardial contractility and whether this action depends on intracardiac rather than circulating angiotensin II, the regional myocardial effects of systemic (i.v.) and intracoronary (i.c.) infusions of the renin inhibitor remikiren, were compared and related to the effects on systemic haemodynamics and circulating angiotensin II in open-chest anaesthetized pigs (25-30 kg). The specificity of the remikiren-induced effects was tested (1) by studying its i.c. effects after administration of the AT1-receptor antagonist L-158,809 and (2) by measuring its effects on contractile force of porcine isolated cardiac trabeculae. 2. Consecutive 10 min i.v. infusions of remikiren were given at 2, 5, 10 and 20 mg min-1. Mean arterial pressure (MAP), cardiac output (CO), heart rate (HR), systemic vascular resistance (SVR), myocardial oxygen consumption (MVO2) and left ventricular (LV) dP/dtmax were not affected by remikiren at 2 and 5 mg min-1, and were lowered at higher doses. At the highest dose, MAP decreased by 48%, CO by 13%, HR by 14%, SVR by 40%, MVO2 by 28% and LV dp/dtmax by 52% (mean values; P < 0.05 for difference from baseline, n = 5). The decrease in MVO2 was accompanied by a decrease in myocardial work (MAP x CO), but the larger decline in work (55% vs. 28%; P < 0.05) implies a reduced myocardial efficiency ((MAP x CO)/MVO2). 3. Consecutive 10 min i.c. infusions of remikiren were given at 0.2, 0.5, 1, 2, 5 and 10 mg min-1. MAP, CO, MVO2 and LV dP/dtmax were not affected by remikiren at 0.2, 0.5 and 1 mg min-1, and were reduced at higher doses. At the highest dose, MAP decreased by 31%, CO by 26%, MVO2 by 46% and LV dP/dtmax by 43% (mean values; P < 0.05 for difference from baseline, n = 6). HR and SVR did not change at any dose. 4. Thirty minutes after a 10 min i.v. infusion of the AT1 receptor antagonist, L-158,809 at 1 mg min-1, consecutive 10 min i.c. infusions (n = 5) of remikiren at 2, 5 and 10 mg min-1 no longer affected CO and MVO2, and decreased LV dP/dtmax by maximally 27% (P < 0.05) and MAP by 14% (P < 0.05), which was less than without AT1-receptor blockade (P < 0.05). HR and SVR remained unaffected. 5. Plasma renin activity and angiotensin I and II were reduced to levels at or below the detection limit at doses of remikiren that were not high enough to affect systemic haemodynamics or regional myocardial function, both after i.v. and i.c. infusion. 6. Remikiren (10(-10) to 10(-4) M) did not affect contractile force of porcine isolated cardiac trabeculae precontracted with noradrenaline. In trabeculae that were not precontracted no decrease in baseline contractility was observed with remikiren in concentrations up to 10(-5) M, whereas at 10(-4) M baseline contractility decreased by 19% (P < 0.05). 7. Results show that with remikiren i.v., at the doses we used, blood pressure was lowered primarily by vasodilation and with remikiren i.c. by cardiac depression. The blood levels of remikiren required for its vasodilator action are lower than the levels affecting cardiac contractile function. A decrease in circulating angiotensin II does not appear to be the sole explanation for these haemodynamic responses. Data support the contention that myocardial contractility is increased by renin-dependent angiotensin II formation in the heart. PMID:8851507

  15. Unrecognized Myocardial Infarction Assessed by Cardiac Magnetic Resonance Imaging – Prognostic Implications

    PubMed Central

    Ahlström, Håkan; Bjerner, Tomas; Duvernoy, Olov; Eggers, Kai M.; Fröbert, Ole; Hadziosmanovic, Nermin

    2016-01-01

    Background Clinically unrecognized myocardial infarctions (UMI) are not uncommon and may be associated with adverse outcome. The aims of this study were to determine the prognostic implication of UMI in patients with stable suspected coronary artery disease (CAD) and to investigate the associations of UMI with the presence of CAD. Methods and Findings In total 235 patients late gadolinium enhancement cardiovascular magnetic resonance (LGE-CMR) imaging and coronary angiography were performed. For each patient with UMI, the stenosis grade of the coronary branch supplying the infarcted area was determined. UMIs were present in 25% of the patients and 67% of the UMIs were located in an area supplied by a coronary artery with a stenosis grade ≥70%. In an age- and gender-adjusted model, UMI independently predicted the primary endpoint (composite of death, myocardial infarction, resuscitated cardiac arrest, hospitalization for unstable angina pectoris or heart failure within 2 years of follow-up) with an odds ratio of 2.9; 95% confidence interval 1.1–7.9. However, this association was abrogated after adjustment for age and presence of significant coronary disease. There was no difference in the primary endpoint rates between UMI patients with or without a significant stenosis in the corresponding coronary artery. Conclusions The presence of UMI was associated with a threefold increased risk of adverse events during follow up. However, the difference was no longer statistically significant after adjustments for age and severity of CAD. Thus, the results do not support that patients with suspicion of CAD should be routinely investigated by LGE-CMR for UMI. However, coronary angiography should be considered in patients with UMI detected by LGE-CMR. Trial Registration ClinicalTrials.gov NTC01257282 PMID:26885831

  16. Low-dose exposure of silica nanoparticles induces cardiac dysfunction via neutrophil-mediated inflammation and cardiac contraction in zebrafish embryos.

    PubMed

    Duan, Junchao; Yu, Yang; Li, Yang; Li, Yanbo; Liu, Hongcui; Jing, Li; Yang, Man; Wang, Ji; Li, Chunqi; Sun, Zhiwei

    2016-06-01

    The toxicity mechanism of nanoparticles on vertebrate cardiovascular system is still unclear, especially on the low-level exposure. This study was to explore the toxic effect and mechanisms of low-dose exposure of silica nanoparticles (SiNPs) on cardiac function in zebrafish embryos via the intravenous microinjection. The dosage of SiNPs was based on the no observed adverse effect level (NOAEL) of malformation assessment in zebrafish embryos. The mainly cardiac toxicity phenotypes induced by SiNPs were pericardial edema and bradycardia but had no effect on atrioventricular block. Using o-Dianisidine for erythrocyte staining, the cardiac output of zebrafish embryos was decreased in a dose-dependent manner. Microarray analysis and bioinformatics analysis were performed to screen the differential expression genes and possible pathway involved in cardiac function. SiNPs induced whole-embryo oxidative stress and neutrophil-mediated cardiac inflammation in Tg(mpo:GFP) zebrafish. Inflammatory cells were observed in atrium of SiNPs-treated zebrafish heart by histopathological examination. In addition, the expression of TNNT2 protein, a cardiac contraction marker in heart tissue had been down-regulated compared to control group using immunohistochemistry. Confirmed by qRT-PCR and western blot assays, results showed that SiNPs inhibited the calcium signaling pathway and cardiac muscle contraction via the down-regulated of related genes, such as ATPase-related genes (atp2a1l, atp1b2b, atp1a3b), calcium channel-related genes (cacna1ab, cacna1da) and the regulatory gene tnnc1a for cardiac troponin C. Moreover, the protein level of TNNT2 was decreased in a dose-dependent manner. For the first time, our results demonstrated that SiNPs induced cardiac dysfunction via the neutrophil-mediated cardiac inflammation and cardiac contraction in zebrafish embryos. PMID:26551753

  17. Cardiac risk assessment before vascular surgery: a prospective study comparing clinical evaluation, dobutamine stress echocardiography, and dobutamine Tc-99m sestamibi tomoscintigraphy.

    PubMed

    Van Damme, H; Pirard, L; Gillain, D; Benoit, T; Rigo, P; Limet, R

    1997-02-01

    Preoperative evaluation for cardiac risk assessment before peripheral vascular surgery remains controversial. Between January and June 1994, a prospective open study was carried out in 156 patients scheduled for elective vascular procedures (63 carotid endarterectomies, 34 abdominal aortic aneurysms, 29 aortoiliac and 30 infrainguinal reconstructions) to compare the ability of clinical data, dobutamine stress echocardiography, and dobutamine Tc-99m sestamibi tomoscintigraphy to predict postoperative cardiac events. Pharmacological stress testing consisted of incremental dobutamine infusion (+/-1 mg atropine to achieve 85% of age-predicted maximal heart rate, with continuous echocardiographic monitoring, and injection of Tc-99m sestamibi after dobutamine infusion). Dobutamine echocardiography was abnormal in 36 patients (worsening resting wall motion abnormality in 11; new induced wall motion abnormality in 25). Dobutamine Tc-99m sestamibi tomoscintigraphy revealed a reversible perfusion defect in 34 patients, indicating the presence of myocardial ischaemia. As a result, eight patients underwent myocardial revascularization (n = 5) or the proposed operation was cancelled (n = 3). In the remaining 142 vascular procedures, there were eight (5.6%) adverse cardiac events: three myocardial infarctions (two fatal), three prolonged myocardial ischaemia, one acute congestive heart failure and one sustained ventricular arrhythmia in the post operative period. Univariate analysis selected unstable angina (relative risk (RR) 11.6), previous congestive heart failure (RR 6.4), Detsky's score of > or = 15 (RR 3.0), positive dobutamine stress echocardiography (RR 3.7), and positive dobutamine tomoscintigraphy (RR 7.4) as significant predictors of postoperative cardiac events. In patients without clinical markers of coronary artery disease (n = 66), non-invasive cardiac testing did not predict cardiac complications (n = 2; one prolonged myocardial ischaemia; one infarction). In the subset of 76 patients with definite clinical or electrocardiographic evidence of ischaemic heart disease, dobutamine stress testing provided additional information, and optimized risk stratification: five of six patients who suffered a cardiac complication had a pathologic dobutamine stress test. Furthermore, a negative dobutamine stress test was characterized by a high negative predictive value (0.96 for echocardiography; 0.97 for tomoscintigraphy). The study further demonstrated that the cardiac response (ischaemic versus non-ischaemic) to dobutamine stress was concordantly classified by echocardiographic and tomoscintigraphic techniques in 96% of cases. It is concluded that complementary non-invasive cardiac stress testing by dobutamine is indicated only in patients with clinically apparent coronary artery disease. PMID:9158124

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

    PubMed Central

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

    2015-01-01

    Background: Early assessment and aggressive hemodynamic treatment have been shown to increase the survival of patients in septic shock. Current and past sepsis guidelines recommend a resuscitation protocol including central venous pressure (CVP), mean arterial blood pressure (MAP), urine output and central venous oxygen saturation (ScvO2) for resuscitation within the first six hours. Currently, the established severity score systems like APACHE II score, SOFA score or SAPS II score predict the outcome of critically ill patients on the bases of variables obtained only after the first 24 hours. The present study aims to evaluate the risk of short-term mortality for patients with septic shock by the earliest possible assessment of hemodynamic parameters and cardiac biomarkers as well as their role for the prediction of the adverse outcome. Methods: 52 consecutive patients treated for septic shock in the intensive care unit of one centre (Marien Hospital Herne, Ruhr University Bochum, Germany) were prospectively enrolled in this study. Hemodynamic parameters (MAP, CVP, ScvO2, left ventricular ejection fraction, Hematocrit) and cardiac biomarkers (Troponin I) at the ICU admission were evaluated in regard to their influence on mortality. The primary endpoint was all-cause mortality within 28 days after the admission. Results: A total of 52 patients (31 male, 21 female) with a mean age of 71.48.5 years and a mean APACHE II score of 37.07.6 were enrolled in the study. 28 patients reached the primary endpoint (mortality 54%). Patients presenting with hypotension (MAP <65 mmHg) at ICU admission had significantly higher rates of 28-day mortality as compared with the group of patients without hypotension (28-day mortality rate 74 % vs. 32 %, p<0.01). Furthermore, the patients in the hypotension present group had significantly higher lactate concentration (p=0.002), higher serum creatinin (p=0.04), higher NTproBNP (p=0.03) and after the first 24 hours higher APACHE II scores (p=0.04). A MAP <65 mmHg was the only hemodynamic parameter significantly predicting the primary endpoint (OR: 4.1, CI: 1.1 - 14.8, p=0.008), whereas the remaining hemodynamic variables CVP, ScvO2, Hematocrit, Troponin I and left ventricular ejection fraction (LVEF) seemed to have no influence on survival. Besides, non-survivors had a significantly higher age (74.19.0 vs. 68.46.9, p=0.01). If hypotension coincided with an age ?72 years, the 28-day mortality rate escalated to 88%. Conclusions: In our study, we identified a risk group with an exceedingly high mortality rate: the patients with an age ?72 years and presenting with hypotension (MAP <65 mmHg). These data can be easily obtained at the time of the very first patient contact. As a result, an aggressive and a more effective treatment can be initiated within the first minutes of the primary care, possibly reducing organ failure and short-term mortality in this risk group. PMID:26392804

  19. [Assessment of cardiac function by left heart catheterization: an analysis of left ventricular pressure-volume (length) loops].

    PubMed

    Sasayama, S; Nonogi, H; Sakurai, T; Kawai, C; Fujita, M; Eiho, S; Kuwahara, M

    1984-01-01

    The mechanical property of the cardiac muscle has been classically analyzed in two ways; shortening of muscle fiber, and the development of tension within the muscle. In the ejecting ventricle, left ventricular (LV) function can be analyzed by the analogous two-dimensional framework of pressure-volume loops, which are provided by plotting the instantaneous volume against corresponding LV pressure. The integral pressure with respect to volume allows to assess a total external ventricular work during ejection. The diastolic pressure-volume relations reflect a chamber stiffness of the ventricle. Force-velocity relations also provide an useful conceptual framework for understanding how the ventricle contracts under given afterload, with modification of preload. In the presence of coronary artery disease, the regional nature of left ventricular contractile function should be defined as well as the global ventricular function as described above, because the latter is determined by the complex interaction of dysfunction of the ischemic myocardium and of compensatory augmentation of shortening of the normally perfused myocardium. We utilized a computer technique to analyze the local wall motion of the ischemic heart by cineventriculography. The boundaries of serial ventricular images are automatically traced and superimposed using the external reference system. Radial grids are drawn from the center of gravity of the end-diastolic image. Measurement of length of each radial grid throughout cardiac cycle provides the analysis of movement of the ventricle at a particular point on the circumference. Using phasic pressure obtained simultaneously with opacification as the common parameter, segmental pressure-length loops are constructed simultaneously at various segments. The loops are similar over the entire circumference in the normal heart, being rectangular in morphology and with synchronous behavior during contraction and relaxation. However, the marked distortion of pressure-length loops with clockwise rotation or figure of eight inscription is observed in the ischemic segments. Systolic work of the ischemic segment diminishes dramatically, and the loops exhibit varying degrees of inclination. The control segment loops also show an inclination to the opposite direction of the ischemic loops. These differences are presumably related to the local redistribution of the myocardial tension during systole in the ischemic ventricle. Thus, the method described should be of particular value in assessing the regional myocardial function in the ischemic ventricle and effects of various interventions which modify ischemia. PMID:6394655

  20. Comparative Assessment of Mitral Regurgitation Severity by Transthoracic Echocardiography and Cardiac Magnetic Resonance Using an Integrative and Quantitative Approach.

    PubMed

    Lopez-Mattei, Juan C; Ibrahim, Homam; Shaikh, Kamran A; Little, Stephen H; Shah, Dipan J; Maragiannis, Dimitrios; Zoghbi, William A

    2016-01-15

    Although transthoracic echocardiography (TTE) and cardiac magnetic resonance (CMR) are validated in quantitation of mitral regurgitation (MR), discrepancies may occur. This study assesses the agreement between TTE and CMR in MR and evaluates characteristics and clinical outcome of patients with discrepancy. From our institutional database, 70 subjects with MR underwent both TTE and CMR within 30days (median 3days). MR was evaluated semiquantitatively (n= 70) using a 4-grade scale and quantitatively (n= 60) with calculation of regurgitant volume (RVol) and regurgitant fraction (RF). Of the 70 subjects, qualitative assessment by TTE yielded 30 subjects with mild MR, 17 moderate, and 23 moderately severe or severe MR. Exact concordance in MR grade was seen in 50% and increased to 91% when considering concordance within one grade of severity (?=0.44). A modest correlation was observed for RVol and RF between both methods (r= 0.59 and 0.54, respectively, p <0.0001). Ten patients had a significant discrepancy in quantitative MR (difference in RF >20%); the frequency of secondary MR was higher (100% vs 46%; p= 0.003) in patients with discrepancy. Although interobserver variability in RF was higher with TTE compared with CMR (-5.5 15% vs 0.1 7.3%), patients with discrepancy were equally distributed by severity and clinical outcome without an overestimation by either method. In conclusion, there is a modest agreement between TTE and CMR in assessing MR severity. In patients with discrepancy, there is a higher prevalence offunctional MR, without a consistent overestimation of MR severity by either method. PMID:26684513

  1. Relationship between adductor pollicis muscle thickness and subjective global assessment in a cardiac intensive care unit

    PubMed Central

    Karst, Fernanda Pickrodt; Vieira, Renata Monteiro; Barbiero, Sandra

    2015-01-01

    Objective To verify the relationship between the adductor pollicis muscle thickness test and the subjective global assessment and to correlate it with other anthropometric methods. Methods This observational cross-sectional study was conducted in the intensive care unit of a cardiology hospital in the state of Rio Grande do Sul, Brazil. The hospitalized patients underwent subjective global assessment and adductor pollicis muscle thickness tests on both hands, along with measurement of the right calf circumference. Laboratory parameters, length of stay, vital signs and electronic medical record data and tests were all collected. Results The study population included 83 patients, of whom 62% were men. The average age was 68.6 12.5 years. The most common reason for hospitalization was acute myocardial infarction (34.9%), and the most common pathology was systolic blood pressure (63.9%), followed by diabetes mellitus (28.9%). According to subjective global assessment classifications, 62.7% of patients presented no nutritional risk, 20.5% were moderately malnourished and 16.9% were severely malnourished. Women had a higher nutritional risk, according to both the subjective global assessment and the adductor pollicis muscle thickness test, the cutoff for which was < 6.5mm (54.8%; p = 0.001). The pathology presenting the greatest nutritional risk was congestive heart failure (p = 0.001). Evaluation of the receiver operating characteristic (ROC) curve between adductor pollicis muscle thickness and subjective global assessment showed the accuracy of the former, with an area of 0.822. Conclusion Adductor pollicis muscle thickness proved to be a good method for evaluating nutritional risk. PMID:26761475

  2. [Multidisciplinary team in cardiac rehabilitation and secondary prevention, from the assessment to the education: an educational project].

    PubMed

    Da Vico, Letizia; Ciompi, Maddalena; Schinin, Francesca; Sogaro, Elena; Mannelli, Weruska; Cortini, Sandro

    2014-03-01

    The authors explain the training project: "Multidisciplinarity in cardiac rehabilitation and secondary prevention: from the evaluation to the therapeutic education", the rationale and purpose of a pathway for patients with ischemic heart disease treated in the acute phase with both medical and surgical means, and then placed in a rehabilitation program. The training project was transformed into a learning event for the Region of Sicily and later for the Region of Tuscany that has adopted it, encouraging the spread over the entire region. It highlights the role of the team, which focuses on the patient, converging on it multidisciplinary expertise whose goal is the reintegration of the subjects in their life-context, with appropriate evaluation, treatment and changes in lifestyle. From the valuations and declining the specific interventions to each job profile according to the principle of synergy obtained by multi-professional integration. All phases of the training project (assessment, intervention, evaluation) are addressed by each of the professionals (nurse, dietitian, physiotherapist, psychologist) that under the responsibility of the cardiologist realize, within the welfare, a concrete process of therapeutic education from which no one can ignore the "vision" of a global care of the patient. PMID:25481939

  3. [Multidisciplinary team in cardiac rehabilitation and secondary prevention, from the assessment to the education: an educational project].

    PubMed

    Da Vico, Letizia; Ciompi, Maddalena; Schinin, Francesca; Sogaro, Elena; Mannelli, Weruska; Cortini, Sandro

    2014-03-01

    The authors explain the training project: "Multidisciplinarity in cardiac rehabilitation and secondary prevention: from the evaluation to the therapeutic education", the rationale and purpose of a pathway for patients with ischemic heart disease treated in the acute phase with both medical and surgical means, and then placed in a rehabilitation program. The training project was transformed into a learning event for the Region of Sicily and later for the Region of Tuscany that has adopted it, encouraging the spread over the entire region. It highlights the role of the team, which focuses on the patient, converging on it multidisciplinary expertise whose goal is the reintegration of the subjects in their life-context, with appropriate evaluation, treatment and changes in lifestyle. From the valuations and declining the specific interventions to each job profile according to the principle of synergy obtained by multi-professional integration. All phases of the training project (assessment, intervention, evaluation) are addressed by each of the professionals (nurse, dietitian, physiotherapist, psychologist) that under the responsibility of the cardiologist realize, within the welfare, a concrete process of therapeutic education from which no one can ignore the "vision" of a global care of the patient. PMID:25508791

  4. Methods for reducing biases and errors in regional photochemical model outputs for use in emission reduction and exposure assessments

    NASA Astrophysics Data System (ADS)

    Porter, P. Steven; Rao, S. Trivikrama; Hogrefe, Christian; Gego, Edith; Mathur, Rohit

    2015-07-01

    In the United States, regional-scale photochemical models are being used to design emission control strategies needed to meet the relevant National Ambient Air Quality Standards (NAAQS) within the framework of the attainment demonstration process. Previous studies have shown that the current generation of regional photochemical models can have large biases and errors in simulating absolute levels of pollutant concentrations. Studies have also revealed that regional air quality models were not always accurately reproducing even the relative changes in ozone air quality stemming from changes in emissions. This paper introduces four approaches to adjust for model bias and errors in order to provide greater confidence for their use in estimating future concentrations as well as using modeled pollutant concentrations in exposure assessments. The four methods considered here are a mean and variance (MV) adjustment, temporal component decomposition (TC) adjustment of modeled concentrations, and two variants of cumulative distribution function (CDF) mapping. These methods were compared against each other as well as against unadjusted model concentrations and a version of the relative response approach based on unadjusted model predictions. The analysis uses ozone concentrations simulated by the Community Multiscale Air Quality (CMAQ) model for the northeastern United States domain for the years 1996-2005. Ensuring that base case conditions are adequately represented through the combined use of observations and model simulations is shown to result in improved estimates of future air quality under changing emissions and meteorological conditions.

  5. Paving the Route to Plasma miR-208a-3p as an Acute Cardiac Injury Biomarker: Preclinical Rat Data Supports Its Use in Drug Safety Assessment.

    PubMed

    Glineur, Stéphanie F; De Ron, Pierrette; Hanon, Etienne; Valentin, Jean-Pierre; Dremier, Sarah; Nogueira da Costa, André

    2016-01-01

    Drug-induced cardiac injury (DICI) detection remains a major safety issue in drug development. While circulating microRNAs (miRs) have emerged as promising translational biomarkers, novel early detection biomarkers of cardiotoxicity are needed. This work aims at evaluating whether a panel of putative cardiac injury plasma miRs could serve as early DICI biomarkers in a 4-day rat preclinical model. Out of a panel of 68 selected targets, we identified plasma miR-208a-3p as being significantly upregulated after single administration with either isoproterenol (ISO) or allylamine (AAM). This provides the first evidence of miR-208a-3p detection after AAM administration. Moreover, similarly to cardiac troponins (cTn), plasma miR-208a-3p expression profile appears to be compound-specific with most significant early changes occurring in ISO-treated rats. Overall, miR-208a-3p performance in detecting the severity of myocardial injury, as well as the magnitude of miR-208a-3p increase after ISO or AAM administration, were comparable to that of cTn. Our results highlight the importance of assessing the whole time-dependent profiles of miR expression. Hence, time course evaluation revealed plasma miR candidates whose expression was not stable across the duration of the study in the vehicle group, restricting their utility as cardiac injury-specific biomarkers. In light of these findings, miR-208a-3p has a potential to complement the existing biomarkers of cardiac injury specifically in the context of evaluating toxicity in a time-dependant manner. Assessment of miR-208a-3p in other DICI settings would strengthen its robustness as an early detection biomarker leading to a warranted extensive and rigorous validation. PMID:26454886

  6. Bibliometric Assessment of European and Sub-Saharan African Research Output on Poverty-Related and Neglected Infectious Diseases from 2003 to 2011

    PubMed Central

    Gurney, Karen A.; Mgone, Charles S.

    2015-01-01

    Background The European & Developing Countries Clinical Trials Partnership (EDCTP) is a partnership of European and sub-Saharan African countries that aims to accelerate the development of medical interventions against poverty-related diseases (PRDs). A bibliometric analysis was conducted to 1) measure research output from European and African researchers on PRDs, 2) describe collaboration patterns, and 3) assess the citation impact of clinical research funded by EDCTP. Methodology/Principal Findings Disease-specific research publications were identified in Thomson Reuters Web of Science using search terms in titles, abstracts and keywords. Publication data, including citation counts, were extracted for 2003–2011. Analyses including output, share of global papers, normalised citation impact (NCI), and geographical distribution are presented. Data are presented as five-year moving averages. European EDCTP member countries accounted for ~33% of global research output in PRDs and sub-Saharan African countries for ~10% (2007–2011). Both regions contributed more to the global research output in malaria (43.4% and 22.2%, respectively). The overall number of PRD papers from sub-Saharan Africa increased markedly (>47%) since 2003, particularly for HIV/AIDS (102%) and tuberculosis (TB) (81%), and principally involving Southern and East Africa. For 2007–2011, European and sub-Saharan African research collaboration on PRDs was highly cited compared with the world average (NCI in brackets): HIV/AIDS 1.62 (NCI: 1.16), TB 2.11 (NCI: 1.06), malaria 1.81 (NCI: 1.22), and neglected infectious diseases 1.34 (NCI: 0.97). The NCI of EDCTP-funded papers for 2003–2011 was exceptionally high for HIV/AIDS (3.24), TB (4.08) and HIV/TB co-infection (5.10) compared with global research benchmarks (1.14, 1.05 and 1.35, respectively). Conclusions The volume and citation impact of papers from sub-Saharan Africa has increased since 2003, as has collaborative research between Europe and sub-Saharan Africa. >90% of publications from EDCTP-funded research were published in high-impact journals and are highly cited. These findings corroborate the benefit of collaborative research on PRDs. PMID:26262756

  7. What to Expect When Starting Cardiac Rehabilitation

    MedlinePLUS

    ... continue cardiac rehab depends on your situation. Health Assessment Before you start cardiac rehab, your rehab team ... steady or irregular). An EKG also shows the strength and timing of electrical signals as they pass ...

  8. Pediatric cardiac emergencies.

    PubMed

    Lee, C; Mason, L J

    2001-06-01

    Successful management of pediatric cardiac emergencies requires an accurate diagnosis to institute an appropriate plan of therapy. The diagnosis, however, is not always straightforward, as evidenced by the nonspecific clinical picture that can be presented by congenital heart defects. Entertaining the possibility of a cardiac problem in neonates with pulmonary symptoms unresponsive to standard therapies is crucial for successful management of patients with congenital heart disease. In addition to ventilatory support, prostaglandin E1 infusions or emergency interventional cardiac catheterization is often a life-saving initial measure in patients with acutely decompensated congenital cardiac lesions that require a patent ductus arteriosus for survival. Pericardial tamponade is associated with various acquired and iatrogenic causes. Emergent pericardiocentesis is mandatory when cardiovascular compromise occurs. The goal of anesthetic management is to maintain cardiac output. With the increasing use of central venous catheters in neonatal ICUs and the high mortality rate for central venous catheter-related cardiac tamponade, the diagnosis must be considered in any patient with a central venous catheter in situ who acutely develops unexplained hypotension, bradycardia, and diminished pulses. Arrhythmias also can cause hemodynamic instability in infants and children. Supraventricular tachycardia is by far the most common emergently presenting arrhythmia in the pediatric population. Unstable patients require immediate intravenous adenosine or synchronized cardioversion. Complete heart block is rare, but it can lead to congestive heart failure and occasionally to cardiovascular collapse and sudden death. Emergency treatment of complete heart block includes pharmacologic support and temporary or permanent pacemaker placement as indicated. In infants, congestive heart failure usually is related to congenital heart disease, whereas in older children, it tends to be secondary to an acquired cause. Supportive measures, fluid restriction, and inotropic support are the principles of initial treatment. Prompt recognition and initiation of appropriate therapy in pediatric cardiac emergencies are essential for favorable outcomes. PMID:11469066

  9. Remote detection of mental workload changes using cardiac parameters assessed with a low-cost webcam.

    PubMed

    Bousefsaf, Frdric; Maaoui, Choubeila; Pruski, Alain

    2014-10-01

    We introduce a new framework for detecting mental workload changes using video frames obtained from a low-cost webcam. Image processing in addition to a continuous wavelet transform filtering method were developed and applied to remove major artifacts and trends on raw webcam photoplethysmographic signals. The measurements are performed on human faces. To induce stress, we have employed a computerized and interactive Stroop color word test on a set composed by twelve participants. The electrodermal activity of the participants was recorded and compared to the mental workload curve assessed by merging two parameters derived from the pulse rate variability and photoplethysmographic amplitude fluctuations, which reflect peripheral vasoconstriction changes. The results exhibit strong correlation between the two measurement techniques. This study offers further support for the applicability of mental workload detection by remote and low-cost means, providing an alternative to conventional contact techniques. PMID:25150821

  10. Monte Carlo simulations to assess differentiation between defects in cardiac SPECT

    NASA Astrophysics Data System (ADS)

    Chrysanthou-Baustert, I.; Parpottas, Y.; Demetriadou, O.; Christofides, S.; Yiannakkaras, Ch; Kaolis, D.; Wasilewska-Radwanska, M.

    2011-09-01

    Differentiating between various types of lesions in nuclear cardiology is a challenge. This work assesses the level of differentiation achievable between various low contrast lesions, as encountered in nuclear cardiology. The parameters investigated are defect extend, defect thickness and perfusion reduction of the defect. The images have been obtained through Monte Carlo Simulations with the program SIMIND. Results show that acceptable size resolution is obtained for defects with an extend over 25×25mm. When thickness and perfusion reduction are both unknown, the imaging results are confounding. In this work, thickness and perfusion reduction cannot be differentiated. If one of the variables is known (thickness or perfusion reduction), imaging results can differentiate between the other unknown variable.

  11. An Assessment of Emergency Department Post-Cardiac Arrest Care Variation in Michigan.

    PubMed

    Kotini-Shah, Pavitra; Camp-Rogers, Teresa R; Swor, Robert A; Sawyer, Kelly N

    2016-03-01

    Implementation of postarrest care by individual physicians and systems has been slow. Deadoption, or discontinuation of therapeutic hypothermia (TH) treatment targets, after recent prospective study results has not been well reported. This study assesses practices in the early stages of postarrest care across emergency departments (EDs) in Michigan. A 27-question Internet-based survey was distributed to EDs in Michigan in September 2013. To assess changes in practice after publication of Nielsen et al., we sent follow-up questions to all original respondents a year later. Observational data and descriptive statistics are reported. From the 142 EDs identified, we excluded critical access hospitals (N = 35), free standing EDs (N = 7), EDs that transfer critical patients to tertiary centers (N = 21), and exclusive children's hospitals (N = 3). Of the remaining 76 hospitals, we received 64 (84.2%) responses. We identified 15 respondents with a protocol to specifically initiate ED TH and transfer patients to a higher level of care. The 49 remaining were mostly teaching institutions (N = 34, 69%) and gave the ED physician the ability to initiate TH (N = 40, 82%). On follow-up 12 months later, we received 33/40 (83%) responses, of which only 5 indicated formal or informal change in TH practice or target temperature. There is substantial variation in the practice of ED postarrest care and initiation of TH across the state of Michigan, but few ED TH protocols were changed in a year's time. The consequences of postarrest treatment variability at the state and ED levels are likely under-recognized as an influence on outcome variation between regions. PMID:26654317

  12. Cardiac Sarcoidosis.

    PubMed

    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. PMID:26593140

  13. Assessing Cardiac Injury in Mice with Dual Energy-microCT, 4D-microCT and microSPECT Imaging Following Partial-Heart Irradiation

    PubMed Central

    Lee, Chang-Lung; Min, Hooney; Befera, Nicholas; Clark, Darin; Qi, Yi; Das, Shiva; Johnson, G. Allan; Badea, Cristian T.; Kirsch, David G.

    2014-01-01

    Purpose To develop a mouse model of cardiac injury following partial-heart irradiation (PHI) and test whether DE-microCT and 4D-microCT can be used to assess cardiac injury after PHI to complement myocardial perfusion imaging using microSPECT. 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; p53FL/+ and Tie2Cre; p53FL/? mice, where one 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; p53FL/? mice. In Tie2Cre; p53FL/? mice, extravasation of AuNp was observed within the irradiated LV, whereas in the myocardium of Tie2Cre; p53FL/+ mice, AuNp were restricted to blood vessels. In addition, data from DE-microCT and microSPECT showed a linear correlation (R2=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 Tie2Cre; p53FL/? mice to develop a markedly decreased ejection fraction, and higher end-diastolic and end-systolic volumes, which were associated with compensatory cardiac hypertrophy of the heart that was not irradiated. Conclusions Our results show that DE-microCT and 4D-microCT with nanoparticle-based contrast agents are novel imaging approaches complementary to microSPECT to non-invasively assess the change in myocardial vascular permeability and cardiac function of mice that develop myocardial injury after PHI. PMID:24521682

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

    SciTech Connect

    Lee, Chang-Lung; Min, Hooney; Befera, Nicholas; Clark, Darin; Qi, Yi; Das, Shiva; Johnson, G. Allan; Badea, Cristian T.; Kirsch, David G.

    2014-03-01

    Purpose: To develop a mouse model of cardiac injury after partial heart irradiation (PHI) and to test whether dual energy (DE)-microCT and 4-dimensional (4D)-microCT can be used to assess cardiac injury after PHI to complement myocardial perfusion imaging using micro-single photon emission computed tomography (SPECT). Methods and Materials: To study cardiac injury from tangent field irradiation in mice, we used a small-field biological irradiator to deliver a single dose of 12 Gy x-rays to approximately one-third of the left ventricle (LV) of Tie2Cre; p53{sup FL/+} and Tie2Cre; p53{sup FL/−} mice, where 1 or both alleles of p53 are deleted in endothelial cells. Four and 8 weeks after irradiation, mice were injected with gold and iodinated nanoparticle-based contrast agents, and imaged with DE-microCT and 4D-microCT to evaluate myocardial vascular permeability and cardiac function, respectively. Additionally, the same mice were imaged with microSPECT to assess myocardial perfusion. Results: After PHI with tangent fields, DE-microCT scans showed a time-dependent increase in accumulation of gold nanoparticles (AuNp) in the myocardium of Tie2Cre; p53{sup FL/−} mice. In Tie2Cre; p53{sup FL/−} mice, extravasation of AuNp was observed within the irradiated LV, whereas in the myocardium of Tie2Cre; p53{sup FL/+} mice, AuNp were restricted to blood vessels. In addition, data from DE-microCT and microSPECT showed a linear correlation (R{sup 2} = 0.97) between the fraction of the LV that accumulated AuNp and the fraction of LV with a perfusion defect. Furthermore, 4D-microCT scans demonstrated that PHI caused a markedly decreased ejection fraction, and higher end-diastolic and end-systolic volumes, to develop in Tie2Cre; p53{sup FL/−} mice, which were associated with compensatory cardiac hypertrophy of the heart that was not irradiated. Conclusions: Our results show that DE-microCT and 4D-microCT with nanoparticle-based contrast agents are novel imaging approaches complementary to microSPECT for noninvasive assessment of the change in myocardial vascular permeability and cardiac function of mice in whom myocardial injury develops after PHI.

  15. Real-Time Assessment of Cardiac Perfusion, Coronary Angiography, and Acute Intravascular Thrombi Using Dual-Channel Near-Infrared Fluorescence Imaging

    PubMed Central

    Tanaka, Eiichi; Chen, Frederick Y.; Flaumenhaft, Robert; Graham, Gwenda J.; Laurence, Rita G.; Frangioni, John V.

    2009-01-01

    Objectives We have developed an image-guided surgery system based on invisible near-infrared (NIR) fluorescent light. Presently, the only clinically-available NIR fluorophore is indocyanine green (ICG), which fluoresces at ? 800 nm and is used for coronary angiography. Our objective was to determine if methylene blue (MB), already FDA-approved for other indications, has useful NIR fluorescence properties for image-guided cardiac surgery. Methods The optical properties of MB were measured after dissolution in 100% serum. Biodistribution and clearance were quantified in organs and tissues after intravenous bolus injection of 2 mg/kg MB in N = 3 rats. Coronary arteriography and cardiac perfusion were imaged in real-time after intravenous bolus injection of 1 mg/kg MB in N = 5 pigs with coronary obstructions. Coronary angiography and acute thrombi were assessed using 800 nm fluorophores, ICG and IR-786-labeled platelets, respectively. Results The peak absorbance and emission of MB as a NIR fluorophore occur at 667 nm and 686 nm, respectively. After intravenous injection, MB provides highly sensitive coronary angiography. A lipophilic cation, MB is extracted rapidly into tissue, with myocardium displaying unusually high uptake. MB permits real-time visualization and quantitative assessment of myocardial perfusion. Because of absent spectral overlap, use of two independent fluorophores on our imaging system permits simultaneous quantification of perfusion, venous drainage and/or intravascular thrombi. Conclusions MB is an effective NIR fluorophore that provides direct visualization of coronary arteriography and cardiac perfusion. In conjunction with ? 800 nm NIR fluorophores, important functional assessments during cardiac surgery are also possible. PMID:19577070

  16. Update on intravenous dipyridamole cardiac imaging in the assessment of ischemic heart disease

    SciTech Connect

    Younis, L.T.; Chaitman, B.R. )

    1990-01-01

    Intravenous dipyridamole is a relative selective coronary vasodilator which, when combined with thallium-201, provides a useful technique to assess myocardial perfusion. The intravenous dipyridamole is administered as an infusion at a rate of 0.14 mg/kg/min for 4 minutes. In the presence of significant coronary artery disease the increase of coronary blood flow is disproportionate between vessels with and without significant coronary lesions, providing the basis for detecting regional differences in flow using thallium-201. The test can be used alone or combined with low level exercise to increase test sensitivity. The test is safe when performed under medical supervision and when patient selection is done appropriately. Most of the side effects induced by dipyridamole infusion are well tolerated by patients and readily reversed with intravenous aminophylline and sublingual nitroglycerin. The average sensitivity and specificity of the dipyridamole thallium scintigraphy test from the major studies are 76% and 70%, respectively. The test is very useful in providing prognostic information in patients who are unable to exercise. A reversible thallium defect after dipyridamole infusion has been shown to be associated with significant mortality and morbidity in patients with documented or suspected coronary artery disease. The use of intravenous dipyridamole has been extended into other modalities of imaging, including 2-dimensional and Doppler echocardiography, to study functional changes in the left ventricular induced by the infusion of intravenous dipyridamole. 52 references.

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

    SciTech Connect

    Goma, Carles; Ruiz, Agustin; Jornet, Nuria; Latorre, Artur; Pallerol, Rosa M.; Carrasco, Pablo; Eudaldo, Teresa; Ribas, Montserrat

    2011-03-15

    Purpose: In the present era of cone-beam CT scanners, the use of the standardized CTDI{sub 100} as a surrogate of the idealized CTDI is strongly discouraged and, consequently, so should be the use of the dose-length product (DLP) as an estimate of the total energy imparted to the patient. However, the DLP is still widely used as a reference quantity to normalize the effective dose for a given scan protocol mainly because the CTDI{sub 100} is an easy-to-measure quantity. The aim of this article is therefore to describe a method for radiation dose assessment in large cone-beam single axial scans, which leads to a straightforward estimation of the total energy imparted to the patient. The authors developed a method accessible to all medical physicists and easy to implement in clinical practice in an attempt to update the bridge between CT dosimetry and the estimation of the effective dose. Methods: The authors used commercially available material and a simple mathematical model. The method described herein is based on the dosimetry paradigm introduced by the AAPM Task Group 111. It consists of measuring the dose profiles at the center and the periphery of a long body phantom with a commercial solid-state detector. A weighted dose profile is then calculated from these measurements. To calculate the CT dosimetric quantities analytically, a Gaussian function was fitted to the dose profile data. Furthermore, the Gaussian model has the power to condense the z-axis information of the dose profile in two parameters: The single-scan central dose, f(0), and the width of the profile, {sigma}. To check the energy dependence of the solid-state detector, the authors compared the dose profiles to measurements made with a small volume ion chamber. To validate the overall method, the authors compared the CTDI{sub 100} calculated analytically to the measurement made with a 100 mm pencil ion chamber. Results: For the central and weighted dose profiles, the authors found a good agreement between the measured dose profile data and the fitted Gaussian functions. The solid-state detector had no energy dependence--within the energy range of interest--and the analytical model succeeded in reproducing the absolute dose values obtained with the pencil ion chamber. For the case of large cone-beam single axial scans, the quantity that better characterizes the total energy imparted to the patient is the weighted dose profile integral (DPI{sub w}). The DPI{sub w} can be easily determined from the two parameters that define the Gaussian functions: f(0) and {sigma}. The authors found that the DLP underestimated the total energy imparted to the patient by more than 20%. The authors also found that the calculated CT dosimetric quantities were higher than those displayed on the scanner console. Conclusions: The authors described and validated a method to assess radiation dose in large cone-beam single axial scans. This method offers a simple and more accurate estimation of the total energy imparted to the patient, thus offering the possibility to update the bridge between CT dosimetry and the estimation of the effective dose for cone-beam CT examinations in radiology, nuclear medicine, and radiation therapy.

  18. Assessing Impacts of Climate Change on Biomass and Species Composition across Russia using a Dynamic Vegetation Model and IPCC Climate Output

    NASA Astrophysics Data System (ADS)

    Shuman, J.; Shugart, H.

    2009-04-01

    The Northern Hemisphere's boreal forests and, in particular, the Siberian boreal forest zone, may have a particularly strong effect on the Earth's climate through mechanisms involving changes in the regional surface albedo. Warmer climate has been implicated in the conversion of Russia's Siberian Larch forests to Dark-Conifer Forests of Spruce and Fir implying a potential positive feedback cycle: a warmer climate can accelerate the natural succession from Larch to Dark-Conifer forest; the resultant albedo change then can promote additional climate warming. This climate/cover feedback motivates development of dynamic models simulating the composition of Russian forest. Utilization of the individual based forest growth model, FAREAST, with climate station data provided by the National Climate Data Center (NCDC) for 2083 Russian stations allowed us to generate baseline biomass values (tCha-1) from year zero to mature forest. The model biomass (tCha-1) was previously validated using independent forest inventory data from across the Russian region. The FAREAST model output represents the average of 200 simulated plots per location for climatic conditions reported for the corresponding station. IPCC climate output data from NCAR's Community Climate System Model 3.0 (CCSM) SRES climate change scenarios, A1B and B1, were used to evaluate detailed changes in biomass (tCha-1) and species composition of forests across Russia in response to warming for stands of various ages. These results are used to identify the location, age and species composition of forests which are vulnerable to climate change. Assessing the forest vulnerability in congruence with the age and species distribution is a powerful tool in understanding forest response to climate change in addition to the forests role in climate/cover feedback associated with albedo change.

  19. 7 Tesla (T) human cardiovascular magnetic resonance imaging using FLASH and SSFP to assess cardiac function: validation against 1.5 T and 3 T

    PubMed Central

    Suttie, J. J.; DelaBarre, L.; Pitcher, A.; van de Moortele, P. F.; Dass, S.; Snyder, C. J.; Francis, J. M.; Metzger, G. J.; Weale, P.; Ugurbil, K.; Neubauer, S.; Robson, M.; Vaughan, T.

    2012-01-01

    We report the first comparison of cardiovascular magnetic resonance imaging (CMR) at 1.5 T, 3 T and 7 T field strengths using steady state free precession (SSFP) and fast low angle shot (FLASH) cine sequences. Cardiac volumes and mass measurements were assessed for feasibility, reproducibility and validity at each given field strength using FLASH and SSFP sequences. Ten healthy volunteers underwent retrospectively electrocardiogram (ECG) gated CMR at 1.5 T, 3 T and 7 T using FLASH and SSFP sequences. B1 and B0 shimming and frequency scouts were used to optimise image quality. Cardiac volume and mass measurements were not significantly affected by field strength when using the same imaging sequence (P > 0.05 for all parameters at 1.5 T, 3 T and 7 T). SSFP imaging returned larger end diastolic and end systolic volumes and smaller left ventricular masses than FLASH imaging at 7 T, and at the lower field strengths (P < 0.05 for each parameter). However, univariate general linear model analysis with fixed effects for sequence and field strengths found an interaction between imaging sequence and field strength (P = 0.03), with a smaller difference in volumes and mass measurements between SSFP and FLASH imaging at 7 T than 1.5 T and 3 T. SSFP and FLASH cine imaging at 7 T is technically feasible and provides valid assessment of cardiac volumes and mass compared with CMR imaging at 1.5 T and 3 T field strengths. PMID:21774009

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

    SciTech Connect

    Koenig, Xaver; Kovar, Michael; Rubi, Lena; Mike, Agnes K.; Lukacs, Peter; Gawali, Vaibhavkumar S.; Todt, Hannes; Hilber, Karlheinz; Sandtner, Walter

    2013-12-01

    The plant alkaloid ibogaine has promising anti-addictive properties. Albeit not licenced as a therapeutic drug, and despite hints that ibogaine may perturb the heart rhythm, this alkaloid is used to treat drug addicts. We have recently reported that ibogaine inhibits human ERG (hERG) potassium channels at concentrations similar to the drugs affinity for several of its known brain targets. Thereby the drug may disturb the heart's electrophysiology. Here, to assess the drug's cardiac ion channel profile in more detail, we studied the effects of ibogaine and its congener 18-Methoxycoronaridine (18-MC) on various cardiac voltage-gated ion channels. We confirmed that heterologously expressed hERG currents are reduced by ibogaine in low micromolar concentrations. Moreover, at higher concentrations, the drug also reduced human Na{sub v}1.5 sodium and Ca{sub v}1.2 calcium currents. Ion currents were as well reduced by 18-MC, yet with diminished potency. Unexpectedly, although blocking hERG channels, ibogaine did not prolong the action potential (AP) in guinea pig cardiomyocytes at low micromolar concentrations. Higher concentrations (≥ 10 μM) even shortened the AP. These findings can be explained by the drug's calcium channel inhibition, which counteracts the AP-prolonging effect generated by hERG blockade. Implementation of ibogaine's inhibitory effects on human ion channels in a computer model of a ventricular cardiomyocyte, on the other hand, suggested that ibogaine does prolong the AP in the human heart. We conclude that therapeutic concentrations of ibogaine have the propensity to prolong the QT interval of the electrocardiogram in humans. In some cases this may lead to cardiac arrhythmias. - Highlights: • We study effects of anti-addiction drug ibogaine on ionic currents in cardiomyocytes. • We assess the cardiac ion channel profile of ibogaine. • Ibogaine inhibits hERG potassium, sodium and calcium channels. • Ibogaine’s effects on ion channels are a potential source of cardiac arrhythmias. • 18-Methoxycoronaridine has a lower affinity for cardiac ion channels than ibogaine.

  1. Assessment of Left Ventricular Function in Cardiac MSCT Imaging by a 4D Hierarchical Surface-Volume Matching Process.

    PubMed

    Garreau, Mireille; Simon, Antoine; Boulmier, Dominique; Coatrieux, Jean-Louis; Le Breton, Hervé

    2006-01-01

    Multislice computed tomography (MSCT) scanners offer new perspectives for cardiac kinetics evaluation with 4D dynamic sequences of high contrast and spatiotemporal resolutions. A new method is proposed for cardiac motion extraction in multislice CT. Based on a 4D hierarchical surface-volume matching process, it provides the detection of the heart left cavities along the acquired sequence and the estimation of their 3D surface velocity fields. A Markov random field model is defined to find, according to topological descriptors, the best correspondences between a 3D mesh describing the left endocardium at one time and the 3D acquired volume at the following time. The global optimization of the correspondences is realized with a multiresolution process. Results obtained on simulated and real data show the capabilities to extract clinically relevant global and local motion parameters and highlight new perspectives in cardiac computed tomography imaging. PMID:23165027

  2. Cardiac Risk Assessment

    MedlinePLUS

    ... drugs. Next » Proudly sponsored by ... Learn more about ... Understanding Your Tests Inside the Lab In the News Article Index About This Site Send Us Your ... so the two dates may not always agree. Understanding Your Tests | Inside the Lab | In the News | Article Index | About This Site | Send Us Your ...

  3. Comparisons of four categories of waste recycling in China's paper industry based on physical input-output life-cycle assessment model.

    PubMed

    Liang, Sai; Zhang, Tianzhu; Xu, Yijian

    2012-03-01

    Waste recycling for paper production is an important component of waste management. This study constructs a physical input-output life-cycle assessment (PIO-LCA) model. The PIO-LCA model is used to investigate environmental impacts of four categories of waste recycling in China's paper industry: crop straws, bagasse, textile wastes and scrap paper. Crop straw recycling and wood utilization for paper production have small total intensity of environmental impacts. Moreover, environmental impacts reduction of crop straw recycling and wood utilization benefits the most from technology development. Thus, using crop straws and wood (including wood wastes) for paper production should be promoted. Technology development has small effects on environmental impacts reduction of bagasse recycling, textile waste recycling and scrap paper recycling. In addition, bagasse recycling and textile waste recycling have big total intensity of environmental impacts. Thus, the development of bagasse recycling and textile waste recycling should be properly limited. Other pathways for reusing bagasse and textile wastes should be explored and evaluated. Moreover, imports of scrap paper should be encouraged to reduce large indirect impacts of scrap paper recycling on domestic environment. PMID:22100716

  4. Comparisons of four categories of waste recycling in China's paper industry based on physical input-output life-cycle assessment model

    SciTech Connect

    Liang Sai; Zhang, Tianzhu; Xu Yijian

    2012-03-15

    Highlights: Black-Right-Pointing-Pointer Using crop straws and wood wastes for paper production should be promoted. Black-Right-Pointing-Pointer Bagasse and textile waste recycling should be properly limited. Black-Right-Pointing-Pointer Imports of scrap paper should be encouraged. Black-Right-Pointing-Pointer Sensitivity analysis, uncertainties and policy implications are discussed. - Abstract: Waste recycling for paper production is an important component of waste management. This study constructs a physical input-output life-cycle assessment (PIO-LCA) model. The PIO-LCA model is used to investigate environmental impacts of four categories of waste recycling in China's paper industry: crop straws, bagasse, textile wastes and scrap paper. Crop straw recycling and wood utilization for paper production have small total intensity of environmental impacts. Moreover, environmental impacts reduction of crop straw recycling and wood utilization benefits the most from technology development. Thus, using crop straws and wood (including wood wastes) for paper production should be promoted. Technology development has small effects on environmental impacts reduction of bagasse recycling, textile waste recycling and scrap paper recycling. In addition, bagasse recycling and textile waste recycling have big total intensity of environmental impacts. Thus, the development of bagasse recycling and textile waste recycling should be properly limited. Other pathways for reusing bagasse and textile wastes should be explored and evaluated. Moreover, imports of scrap paper should be encouraged to reduce large indirect impacts of scrap paper recycling on domestic environment.

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

    NASA Astrophysics Data System (ADS)

    Liao, Fang-Tsu; Chang, Cheng-Yi; Su, Ming-Tsan; Kuo, Wen-Chuan

    2014-01-01

    Prior studies have established the necessity of an angiotensin-converting enzyme-related (ACER) gene for heart morphogenesis of Drosophila. Nevertheless, the physiology of ACER has yet to be comprehensively understood. Herein, we employed RNA interference to down-regulate the expression of ACER in Drosophila's heart and swept source optical coherence tomography to assess whether ACER is required for cardiac functions in living adult flies. Several contractile parameters of Drosophila heart, including the heart rate (HR), end-diastolic diameter (EDD), end-systolic diameter (ESD), percent fractional shortening (%FS), and stress-induced cardiac performance, are shown, which are age dependent. These age-dependent cardiac functions declined significantly when ACER was down-regulated. Moreover, the lifespans of ACER knock-down flies were significantly shorter than those of wild-type control flies. Thus, we posit that ACER, the Drosophila ortholog of mammalian angiotensin-converting enzyme 2 (ACE2), is essential for both heart physiology and longevity of animals. Since mammalian ACE2 controls many cardiovascular physiological features and is implicated in cardiomyopathies, our findings that ACER plays conserved roles in genetically tractable animals will pave the way for uncovering the genetic pathway that controls the renin-angiotensin system.

  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.

    PubMed

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

    2016-01-01

    Cardiovascular disease is a leading cause of death in captive chimpanzees and is often associated with myocardial fibrosis, which increases the risk of cardiac arrhythmias. In this case report, we present a 36-y-old male chimpanzee (Pan troglodytes) diagnosed with frequent ventricular premature complexes (VPC). We placed a subcutaneous implantable loop recorder for continual ECG monitoring to assess his arrhythmias without the confounding effects of anesthetics. During his initial treatment with the antiarrhythmia medication amiodarone, he developed thrombocytopenia, and the drug was discontinued. After reviewing other potential therapies for the treatment of cardiac arrhythmias, we elected to try acupuncture and laser therapy in view of the positive results and the lack of adverse side effects reported in humans. We used 2 well-known cardiac acupuncture sites on the wrist, PC6 (pericardium 6) and HT7 (heart 7), and evaluated the results of the therapy by using the ECG recordings from the implantable loop recorder. Although periodic increases in the animal's excitement level introduced confounding variables that caused some variation in the data, acupuncture and laser therapy appeared to decrease the mean number of VPC/min in this chimpanzee. PMID:26884410

  7. Assessment of the Right Ventricular Function and Mass Using Cardiac Multi-Detector Computed Tomography in Patients with Chronic Obstructive Pulmonary Disease

    PubMed Central

    Hur, Jin; Kim, Sang Jin; Ryu, Young Hoon; Kim, Hyung Jung

    2007-01-01

    Objective We wanted to assess the relationship between measurements of the right ventricular (RV) function and mass, with using cardiac multi-detector computed tomography (MDCT) and the severity of chronic obstructive pulmonary disease (COPD) as determined by the pulmonary function test (PFT). Materials and Methods Measurements of PFT and cardiac MDCT were obtained in 33 COPD patients. Using the Global Initiative for Chronic Obstructive Lung Disease (GOLD) classification, the patients were divided into three groups according to the severity of the disease: stage I (mild, n = 4), stage II (moderate, n = 15) and stage III (severe, n = 14). The RV function and the wall mass were obtained by cardiac MDCT. The results were compared among the groups using the Student-Newman-Keuls method. Pearson's correlation was used to evaluate the relationship between the right ventricular ejection fraction (RVEF) and the wall mass results with the PFT results. P-values less than 0.05 were considered statistically significant. Results The RVEF and mass were 47±3% and 41±2 g in stage I, 46±6% and 46±5 g in stage II, and 35±5% and 55±6 g in stage III, respectively. The RVEF was significantly lower in stage III than in stage I and II (p < 0.01). The RV mass was significantly different among the three stages, according to the disease severity of COPD (p < 0.05). The correlation was excellent between the MDCT results and forced expiratory volume in 1 sec (r = 0.797 for RVEF and r = -0.769 for RV mass) and forced expiratory volume in 1 sec to the forced vital capacity (r = 0.745 for RVEF and r = -0.718 for RV mass). Conclusion Our study shows that the mean RV wall mass as measured by cardiac MDCT correlates well with the COPD disease severity as determined by PFT. PMID:17277559

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

    PubMed

    Jenkins, Kathy J; Beekman Iii, Robert H; Bergersen, Lisa J; Everett, Allen D; Forbes, Thomas J; Franklin, Rodney C G; Klitzner, Thomas S; Krogman, Otto N; Martin, Gerard R; Webb, Catherine L

    2008-12-01

    This review includes a brief discussion, from the perspective of the pediatric cardiologist, of the rationale for creation and maintenance of multi-institutional databases of outcomes of the treatment of patients with congenital and paediatric cardiac disease, together with a history of the evolution of such databases, and a description of the current state of the art. A number of projects designed to have broad-based impact are currently in the design phase, or have already been implemented. Not surprisingly, most of the efforts thus far have focused on catheterization procedures and interventions, although some work examining other aspects of paediatric cardiology practice is also beginning. This review briefly describes several European and North American initiatives related to databases for pediatric and congenital cardiology including the Central Cardiac Audit Database of the United Kingdom, national database initiatives for pediatric cardiology in Switzerland and Germany, various database initiatives under the leadership of the Working Groups of The Association for European Paediatric Cardiology, the IMPACT Registry (IMproving Pediatric and Adult Congenital Treatment) of the National Cardiovascular Data Registry of The American College of Cardiology Foundation and The Society for Cardiovascular Angiography and Interventions (SCAI), the Mid-Atlantic Group of Interventional Cardiology (MAGIC) Catheterization Outcomes Project, the Congenital Cardiac Catheterization Project on Outcomes (C3PO), the Congenital Cardiovascular Interventional Study Consortium (CCISC), and the Joint Council on Congenital Heart Disease (JCCHD) National Quality Improvement Initiative. These projects, each leveraging multicentre data and collaboration, demonstrate the enormous progress that has occurred over the last several years to improve the quality and consistency of information about nonsurgical treatment for congenital cardiac disease. The paediatric cardiology field is well-poised to move quickly beyond outcome assessment and benchmarking, to collaborative quality improvement. PMID:19063781

  9. A pilot study to assess the feasibility of a submaximal exercise test to measure individual response to cardiac medication in dogs with acquired heart failure.

    PubMed

    Ferasin, L; Marcora, S

    2007-08-01

    Exercise testing is not commonly used in canine medicine because of several limitations. The aim of this study was to investigate the suitability of a treadmill test to measure the exercise capacity of untrained canine cardiac patients and to measure some biological parameters that might reflect the tolerance of dogs with heart failure to submaximal exercise. The exercise capacity of seven dogs with naturally occurring heart failure was evaluated before the institution of cardiac medication and 7 days after the beginning of the study. An additional re-examination was requested after 28 days. The exercise test was performed on a motorized treadmill at three different speeds (0.5 m/s, 1.0 m/s and 1.5 m/s). The following parameters were measured at the end of each stage and after 20 min recovery: heart rate, rectal temperature, glucose, lactate, aspartate aminotransferase, creatine kinase, PvO(2), PvCO(2), pH, haematocrit, bicarbonate, sodium, potassium and chloride. Serum cardiac troponin-I was also measured at the beginning of the test and at the end of the recovery period. Owners' perception reflected the ability of their dogs to exercise on the treadmill. Lactate level increased noticeably with the intensity of the exercise test, and its variation coincided with different exercise tolerance observed by the owners. Heart rate seemed to follow a similar trend in the few dogs presented in sinus rhythm. None of the remaining parameters appeared to be sensitive indicators of activity level in the dogs used in this study. The treadmill exercise test in dogs with acquired heart failure is feasible and might provide useful information for assessing individual response to cardiac medication. Lactate and heart rate seemed to reflect individual levels of exercise tolerance, although further studies are necessary to confirm the reliability and repeatability of this test. PMID:17253114

  10. Digital cardiac imaging

    SciTech Connect

    Buda, A.J.; Delp, E.J.

    1985-01-01

    This book contains 16 papers. Some of the titles are: The analysis of left ventricular function with digital subtraction angiography; Digital radiographic assessment of coronary flow reserve; Clinical application of cardiac CT; Digital two-dimensional echocardiography; and Magnetic resonance imaging of the heart.

  11. Nonexercise cardiac stress testing

    SciTech Connect

    Vacek, J.L.; Baldwin, T. )

    1989-09-15

    Many patients who require evaluation for coronary artery disease are unable to undergo exercise stress testing because of physiologic or psychological limitations. Drs Vacek and Baldwin describe three alternative methods for assessment of cardiac function in these patients, all of which have high levels of diagnostic sensitivity and specificity. 23 references.

  12. Cardiac Catheterization

    MedlinePLUS

    ... done during a cardiac catheterization include: closing small holes inside the heart repairing leaky or narrow heart ... bandage. It's normal for the site to be black and blue, red, or slightly swollen for a ...

  13. Cardiac Catheterization

    MedlinePLUS

    ... where the catheter was inserted. Cardiac catheterization rarely causes serious complications. Rate This Content: NEXT >> Updated: January 30, 2012 Twitter Facebook YouTube Google+ SITE INDEX ACCESSIBILITY PRIVACY STATEMENT FOIA ...

  14. Cardiac tamponade

    MedlinePLUS

    ... blood. Cardiac tamponade can occur due to: Dissecting aortic aneurysm (thoracic) End-stage lung cancer Heart attack ( acute ... is felt in the neck, shoulder, back, or abdomen Chest pain that gets worse with deep breathing ...

  15. Cardiac amyloidosis

    MedlinePLUS

    ... body. Medicines including digoxin, calcium channel blockers, and beta blockers may be used in people with atrial fibrillation. However, the drugs must be used with caution, and the dosage must be carefully monitored. People with cardiac amyloidosis ...

  16. Cardiac Effects of Echinocandins in Endotoxemic Rats.

    PubMed

    Koch, Christian; Wolff, Matthias; Henrich, Michael; Weigand, Markus A; Lichtenstern, Christoph; Uhle, Florian

    2015-01-01

    Echinocandins are known as effective and safe agents for the prophylaxis and treatment of different cohorts of patients with fungal infections. Recent studies revealed that certain pharmacokinetics of echinocandin antifungals might impact clinical efficacy and safety in special patient populations. The aim of our study was to evaluate echinocandin-induced aggravation of cardiac impairment in septic shock. Using an in vivo endotoxemic shock model in rats, we assessed hemodynamic parameters and time to hemodynamic failure (THF) after additional central-venous application of anidulafungin (2.5 mg/kg of body weight [BW]), caspofungin (0.875 mg/kg BW), micafungin (3 mg/kg BW), and control (0.9% sodium chloride). In addition, echinocandin-induced cytotoxicity was evaluated in isolated rat cardiac myocytes. THF of the animals in the caspofungin group (n = 7) was significantly reduced compared to that in the control (n = 6) (136 min versus 180 min; P = 0.0209). The anidulafungin group (n = 7) also showed a trend of reduced THF (136 min versus 180 min; log-rank test P = 0.0578). Animals in the micafungin group (n = 7) did not show significant differences in THF compared to those in the control. Control group animals and also micafungin group animals did not show altered cardiac output (CO) during our experiments. In contrast, administration of anidulafungin or caspofungin induced a decrease in CO. We also revealed a dose-dependent increase of cytotoxicity in anidulafungin- and caspofungin-treated cardiac myocytes. Treatment with micafungin did not cause significantly increased cytotoxicity. Further studies are needed to explore the underlying mechanism. PMID:26503647

  17. Current trends in cardiac CT in children.

    PubMed

    Goo, Hyun Woo

    2013-11-01

    Cardiac CT is increasingly utilized in children thanks to advanced scan techniques reducing cardiac and respiratory motion artifacts. Consequently, clinical indications of cardiac CT are not confined to the extracardiac evaluation and extended further to the assessment of intracardiac structures, coronary arteries, ventricular volumetry, and ventricular function. In addition, dual-energy CT allows the assessment of regional lung perfusion and ventilation. Four-dimensional airway evaluation is also useful and may be added to cardiac CT protocols. At the same time, a favorable risk-benefit ratio of cardiac CT can be achieved by means of various dose-saving techniques. Therefore, flexible scan techniques with minimal motion artifacts, low dose techniques without compromising excellent image quality, and extended clinical applications towards truly cardiac assessments constitute current trends in cardiac CT in children. PMID:23104372

  18. Cardiac Ultrasonography in the critical care setting: a practical approach to asses cardiac function and preload for the "non-cardiologist".

    PubMed

    Vermeiren, Guy L J; Malbrain, Manu L N G; Walpot, Jeroen M J B

    2015-01-01

    Cardiac ultrasonography has become an indispensible tool in the management of hemodynamically unstable critically ill patients. Some consider it as the modern stethoscope. Echocardiography is non-invasive and safe while the modern portable devices allow to be used at the bedside in order to provide fast, specific and vital information regarding the hemodynamic status, as well as the function, structure and anatomy of the heart. In this review, we will give an overview of cardiac function in general followed by an assessment of left ventricular function using echocardiography with calculation of cardiac output, left ventricular ejection fraction (EF), fractional shortening, fractional area contraction, M mode EF, 2D planimetry and 3D volumetry. We will briefly discuss mitral annulus post systolic excursion (MAPSE), calculation of dP/dt, speckle tracking or eyeballing to estimate EF for the experienced user. In a following section, we will discuss how to assess cardiac preload and diastolic function in 4 simple steps. The first step is the assessment of systolic function. The next step assesses the left atrium. The third step evaluates the diastolic flow patterns and E/e' ratio. The final step integrates the information of the previous steps. Echocardiography is also the perfect tool to evaluate right ventricular function with tricuspid annular plane systolic excursion (TAPSE), tissue Doppler imaging, together with inferior vena cava dimensions and systolic pulmonary artery pressure and right ventricular systolic pressure measurement. Finally, methods to assess fluid responsiveness with echocardiography are discussed with the inferior vena cava collapsibility index and the variation on left ventricle outflow tract peak velocity and velocity time integral. Cardiac ultrasonography is an indispensible tool for the critical care physician to assess cardiac preload, afterload and contractile function in hemodynamically unstable patients in order to fine-tune treatment with fluids, inotropes and/or vasopressors. PMID:26588484

  19. Cardiac catheterization and angiography, 3d Ed

    SciTech Connect

    Grossman, W.

    1986-01-01

    This textbook was first published in 1974 and subsequently revised in 1980. The current edition, in seven parts and 33 chapters, has been extensively rewritten, and new chapters have been added that present recently developed techniques. The references have been updated to 1985. The purpose of this work is to provide a concise description of the major techniques employed in cardiac catheterization and angiography. Part 1 deals with the history, general principles, and practice of cardiac catheterization and angiography. In part 2, various techniques of cardiac catheterization are discussed and compared. In part 3, techniques for the determination of cardiac output, pressure, resistance, valve area, and shunt flow are described. Part 4 deals briefly with coronary angiography, cardiac ventriculography, pulmonary angiography, and aortography. In part 5, techniques for evaluating cardiac function and intracardiac electrophysiology are presented. The characteristic hemodynamic and angiographic abnormalities in specific disorders are described in part 6. Part 7 deals with special catheter techniques.

  20. Cardiac factors in orthostatic hypotension

    NASA Astrophysics Data System (ADS)

    Lllgen, H.; Dirschedl, P.; Koppenhagen, K.; Klein, K. E.

    Cardiac function is determined by preload, afterload, heart rate and contractility. During orthostatic stress, the footward blood shift is compensated for by an increase of afterload. LBNP is widely used to analyze effects of volume displacement during orthostatic stress. Comparisons of invasive ( right heart catheterization) and non-invasive approach (echocardiography) yielded similar changes. Preload and afterload change with graded LBNP, heart rate increases, and stroke volume and cardiac output decrease. Thus, the working point on the left ventricular function curve is shifted to the left and downward, similar to hypovolemia. However, position on the Frank-Starling curve, the unchanged ejection fraction, and the constant Vcf indicate a normal contractile state during LBNP. A decrease of arterial oxygen partial pressure during LBNP shwos impaired ventilation/perfusion ratio. Finally, LBNP induced cardiac and hemodynamic changes can be effectively countermeasured by dihydroergotamine, a potent venoconstrictor. Comparison of floating catheter data with that of echocardiography resulted in close correlation for cardiac output and stroke volume. In addition, cardiac dimensions changed in a similar way during LBNP. From our findings, echocardiography as a non-invasive procedure can reliably used in LBNP and orthostatic stress tests. Some informations can be obtained on borderline values indicating collaps or orthostatic syncope. Early fainters can be differentiated from late fainters by stroke volume changes.

  1. Assessing the Impacts of Climate Change on the Distribution of Trout Species in the Sierra Nevada Region of California Using Output from a Landscape Scale Hydrological Model

    NASA Astrophysics Data System (ADS)

    Anthony, M. M.; Ficklin, D. L.; Stewart, I. T.; Knouft, J.

    2014-12-01

    Species distribution models (SDMs) are statistical tools that combine data on the locations where a species is known to occur with data on the environment. The resulting species-environment relationships are then used to identify regions a species could occupy and are often used to make predictions about how a species will respond to climate change. The data used in SDMs generally exhibit a pattern known as spatial autocorrelation (SAC), which is the positive association between the proximity of sample locations. The presence of SAC violates the statistical assumptions that must be met for unbiased estimation of species-environment relationships and can cause traditional SDMs to exhibit low predictive accuracy. To determine the effects of SAC on predicting species' responses to climate change, the distributions of three species of trout were predicted throughout the Sierra Nevada mountain range in California. Measures of contemporary streamflow, water temperature, dissolved oxygen, and sediment concentration are based on model outputs from the Soil and Water Assessment Tool (SWAT) landscape scale hydrological model. SWAT-derived future hydrological conditions driven by downscaled General Circulation Models (GCMs) indicate that increasing temperatures and changes in precipitation will alter these variables across the region, all of which have the ability to negatively impact the distribution of trout species. Trout distribution data along with data on contemporary stream flow, water temperature, dissolved oxygen and sediment concentration from the years 1990 to 1999 were used to develop both spatial and non-spatial SDMs for each species. These species-environment relationships along with data on future environmental conditions for the years 2050-2059 derived from three separate GCM scenarios were then used to predict the future distribution of each species. Predictions from spatial and non-spatial models will be discussed with a focus on the difference in area and the amount of overlap between current and future distributions of each species.

  2. Echocardiographic assessment of left ventricular function in thyrotoxicosis and implications for the therapeutics of thyrotoxic cardiac disease

    PubMed Central

    Anakwue, Raphael C; Onwubere, Basden J; Ikeh, Vincent; Anisiuba, Benedict; Ike, Samuel; Anakwue, Angel-Mary C

    2015-01-01

    Introduction Thyrotoxicosis is an endocrine disorder with prominent cardiovascular manifestations. Thyroid hormone acts through genomic and non-genomic mechanisms to regulate cardiac function. Echocardiography is a useful, non-invasive, easily accessible, and affordable tool for studying the structural and physiological function of the heart. Aim We studied thyrotoxicosis patients in a Nigerian Teaching Hospital and employed trans-thoracic echocardiography to find out if there were abnormalities in the hearts of these patients. Methods Fifty adult thyrotoxicosis patients diagnosed with clinical and thyroid function tests in the medical out-patient unit of the hospital were recruited and we performed transthoracic echocardiography with a Sonos 2000 HP machine. Results We documented the presence of abnormalities in the following proportion of thyrotoxicosis patients: left ventricular enhanced systolic function in 30%, enhanced diastolic function in 34%, diastolic dysfunction in 34%, heart failure with preserved ejection fraction in10%, heart failure with reduced ejection fraction in 6%, and left ventricular hypertrophy in 34%. Conclusion Echocardiography was useful in the stratification of cardiac function abnormalities and is indispensable as a guide in the choice of therapeutic options in patients with thyrocardiac disease. The finding of left ventricular enhanced systolic and diastolic functions signify early echocardiographic detectable cardiac abnormalities in thyrotoxicosis, and the clinical management includes the use of anti-thyroid drugs and β-adrenoceptor blockade. Diastolic dysfunction in thyrotoxicosis patients asymptomatic for cardiac disease should be treated with anti-thyroid drugs, and β-adrenoceptor blockade. The judicious application of clinical therapeutics will guide the use of anti-thyroid drugs, diuretics, digoxin, angiotensin inhibitors, and β-adrenoceptor blockade in the successful management of thyrotoxicosis patients with heart failure and reduced, preserved, or increased ejection fraction: parameters which are derived from echocardiography. PMID:25709461

  3. Using MERRA, AMIP II, CMIP5 Outputs to Assess Actual and Potential Building Climate Zone Change and Variability From the Last 30 Years Through 2100

    NASA Astrophysics Data System (ADS)

    Stackhouse, P. W.; Westberg, D. J.; Hoell, J. M., Jr.; Chandler, W.; Zhang, T.

    2014-12-01

    In the US, residential and commercial building infrastructure combined consumes about 40% of total energy usage and emits about 39% of total CO2emission (DOE/EIA "Annual Energy Outlook 2013"). Thus, increasing the energy efficiency of buildings is paramount to reducing energy costs and emissions. Building codes, as used by local and state enforcement entities are typically tied to the dominant climate within an enforcement jurisdiction classified according to various climate zones. These climates zones are based upon a 30-year average of local surface observations and are developed by DOE and ASHRAE (formerly known as the American Society of Hearting, Refrigeration and Air-Conditioning Engineers). A significant shortcoming of the methodology used in constructing such maps is the use of surface observations (located mainly near airports) that are unequally distributed and frequently have periods of missing data that need to be filled by various approximation schemes. This paper demonstrates the usefulness of using NASA's Modern Era Retrospective-analysis for Research and Applications (MERRA) atmospheric data assimilation to derive the ASHRAE climate zone maps and then using MERRA to define the last 30 years of variability in climate zones. These results show that there is a statistically significant increase in the area covered by warmer climate zones and some tendency for a reduction of area in colder climate zones that require longer time series to confirm. Using the uncertainties of the basic surface temperature and precipitation parameters from MERRA as determined by comparison to surface measurements, we first compare patterns and variability of ASHRAE climate zones from MERRA relative to present day climate model runs from AMIP simulations to establish baseline sensitivity. Based upon these results, we assess the variability of the ASHRAE climate zones according to CMIP runs through 2100 using an ensemble analysis that classifies model output changes by percentiles. Estimates of statistical significance are then compared to original model variability during the AMIP period. This work quantifies and tests for significance the changes seen in the various US regions that represent a potential contribution by NASA to the ongoing National Climate Assessment.

  4. Magnetic Resonance Elastography as a Method for the Assessment of Effective Myocardial Stiffness throughout the Cardiac Cycle

    PubMed Central

    Kolipaka, Arunark; Araoz, Philip A.; McGee, Kiaran P.; Manduca, Armando; Ehman, Richard L.

    2011-01-01

    Magnetic resonance elastography (MRE) is a noninvasive technique in which images of externally generated waves propagating in tissue are used to measure stiffness. The first aim is to determine, from a range of driver configurations the optimal driver for the purpose of generating waves within the heart in vivo. The second aim is to quantify the shear stiffness of normal myocardium throughout the cardiac cycle using MRE and to compare MRE stiffness to left ventricular (LV) chamber pressure in an in vivo pig model. MRE was performed in 6-pigs with 6-different driver setups including no motion, 3-noninvasive drivers and 2-invasive drivers. MRE wave displacement amplitudes were calculated for each driver. During the same MRI examination, LV pressure and MRI-measured LV volume were obtained, and MRE myocardial stiffness was calculated for 20 phases of the cardiac cycle. No discernible waves were imaged when no external motion was applied, and a single pneumatic drum driver produced higher amplitude waves than the other noninvasive drivers (P <0.05). Pressure-volume loops overlaid onto stiffness-volume loops showed good visual agreement. Pressure and MRE-measured effective stiffness showed good correlation (R2 = 0.84). MRE shows potential as a noninvasive method for estimating effective myocardial stiffness throughout the cardiac cycle. PMID:20578052

  5. Functional Assessment of Cardiac Responses of Adult Zebrafish (Danio rerio) to Acute and Chronic Temperature Change Using High-Resolution Echocardiography

    PubMed Central

    Cua, Michelle; Sheng, Xiaoye; Rayani, Kaveh; Beg, Mirza F.; Sarunic, Marinko V.; Tibbits, Glen F.

    2016-01-01

    The zebrafish (Danio rerio) is an important organism as a model for understanding vertebrate cardiovascular development. However, little is known about adult ZF cardiac function and how contractile function changes to cope with fluctuations in ambient temperature. The goals of this study were to: 1) determine if high resolution echocardiography (HRE) in the presence of reduced cardiodepressant anesthetics could be used to accurately investigate the structural and functional properties of the ZF heart and 2) if the effect of ambient temperature changes both acutely and chronically could be determined non-invasively using HRE in vivo. Heart rate (HR) appears to be the critical factor in modifying cardiac output (CO) with ambient temperature fluctuation as it increases from 78 ± 5.9 bpm at 18°C to 162 ± 9.7 bpm at 28°C regardless of acclimation state (cold acclimated CA– 18°C; warm acclimated WA– 28°C). Stroke volume (SV) is highest when the ambient temperature matches the acclimation temperature, though this difference did not constitute a significant effect (CA 1.17 ± 0.15 μL at 18°C vs 1.06 ± 0.14 μl at 28°C; WA 1.10 ± 0.13 μL at 18°C vs 1.12 ± 0.12 μl at 28°C). The isovolumetric contraction time (IVCT) was significantly shorter in CA fish at 18°C. The CA group showed improved systolic function at 18°C in comparison to the WA group with significant increases in both ejection fraction and fractional shortening and decreases in IVCT. The decreased early peak (E) velocity and early peak velocity / atrial peak velocity (E/A) ratio in the CA group are likely associated with increased reliance on atrial contraction for ventricular filling. PMID:26730947

  6. Functional Assessment of Cardiac Responses of Adult Zebrafish (Danio rerio) to Acute and Chronic Temperature Change Using High-Resolution Echocardiography.

    PubMed

    Lee, Ling; Genge, Christine E; Cua, Michelle; Sheng, Xiaoye; Rayani, Kaveh; Beg, Mirza F; Sarunic, Marinko V; Tibbits, Glen F

    2016-01-01

    The zebrafish (Danio rerio) is an important organism as a model for understanding vertebrate cardiovascular development. However, little is known about adult ZF cardiac function and how contractile function changes to cope with fluctuations in ambient temperature. The goals of this study were to: 1) determine if high resolution echocardiography (HRE) in the presence of reduced cardiodepressant anesthetics could be used to accurately investigate the structural and functional properties of the ZF heart and 2) if the effect of ambient temperature changes both acutely and chronically could be determined non-invasively using HRE in vivo. Heart rate (HR) appears to be the critical factor in modifying cardiac output (CO) with ambient temperature fluctuation as it increases from 78 5.9 bpm at 18C to 162 9.7 bpm at 28C regardless of acclimation state (cold acclimated CA- 18C; warm acclimated WA- 28C). Stroke volume (SV) is highest when the ambient temperature matches the acclimation temperature, though this difference did not constitute a significant effect (CA 1.17 0.15 ?L at 18C vs 1.06 0.14 ?l at 28C; WA 1.10 0.13 ?L at 18C vs 1.12 0.12 ?l at 28C). The isovolumetric contraction time (IVCT) was significantly shorter in CA fish at 18C. The CA group showed improved systolic function at 18C in comparison to the WA group with significant increases in both ejection fraction and fractional shortening and decreases in IVCT. The decreased early peak (E) velocity and early peak velocity / atrial peak velocity (E/A) ratio in the CA group are likely associated with increased reliance on atrial contraction for ventricular filling. PMID:26730947

  7. Measurement of cardiac reserve in cardiogenic shock: implications for prognosis and management.

    PubMed Central

    Tan, L B; Littler, W A

    1990-01-01

    The hypothesis that the prognosis of cardiogenic shock patients is primarily dependent on cardiac pumping reserve was tested in a prospective study of 28 consecutive patients clinically diagnosed to be in cardiogenic shock and treated medically. Haemodynamic function was assessed by thermodilution Swan-Ganz catheters and arterial cannulas. The cardiac pumping reserve was evaluated by the response of the failing heart to graded incremental dobutamine infusion (2.5 to 40 micrograms/kg/min) after optimalising the left ventricular preload. Eleven of the patients survived for more than the one year of follow up and the rest died. Haemodynamic evaluation during the basal resting state was only able to identify unambiguously non-survivors whose cardiac function was most severely compromised. Survivors and non-survivors with higher values were indistinguishable by basal haemodynamic criteria. The response to dobutamine stimulation clearly separated the cardiac pump function of survivors and those who died. All patients with peak cardiac power output of less than 1.0 W or peak left ventricular stroke work index of less than 0.25 J/m2 died whereas all those with higher values lived for more than a year. Thus this study showed that haemodynamic evaluation of cardiac reserve can provide objective criteria for predicting outcome in individual patients with cardiogenic shock. The availability of such a prognostic indicator will be invaluable in formulating management plans for these patients. PMID:2393609

  8. Cardiac emergencies in children.

    PubMed

    Schamberger, M S

    1996-06-01

    Pediatric cardiac emergencies require very specific treatment in the emergency room setting. Considering the possibility of a cardiac problem as the cause for the presenting symptoms is the initial step in successful management. Many patients present with what is initially considered a primary pulmonary disorder such as pneumonia, asthma, or bronchiolitis. Airway stabilization and ventilatory support, if needed, remain the first steps in stabilizing the patient. Many neonates with acutely decompensating heart disease may require the patency of the ductus arteriosus for survival. Prostaglandin E given as continuous infusion is the treatment of choice. Congestive heart failure can present at any age. In older patients, it is often due to myocarditis and is characterized by low cardiac output. Supportive measures, fluid restriction, and inotropic support are the basic concepts for initial treatment. Supraventricular tachycardia is a frequent arrhythmia, especially in young children. If the patient is unstable, immediate intravenous administration of adenosine or synchronized cardioversion are the initial interventions. In stable patients, vagal maneuvers may be attempted to abort the arrhythmia. PMID:8793920

  9. Cardiac sarcoidosis

    PubMed Central

    Smedema, J.P.; Zondervan, P.E.; van Hagen, P.; ten Cate, F.J.; Bresser, P.; Doubell, A.F.; Pattynama, P.; Hoogsteden, H.C.; Balk, A.H.M.M.

    2002-01-01

    Sarcoidosis is a multi-system granulomatous disorder of unknown aetiology. Symptomatic cardiac involvement occurs in approximately 5% of patients. The prevalence of sarcoidosis in the Netherlands is unknown, but estimated to be approximately 20 per 100,000 population (3200 patients). We report on five patients who presented with different manifestations of cardiac sarcoidosis, and give a brief review on the current management of this condition. Magnetic Resonance Imaging (MRI) can be of great help in diagnosing this condition as well as in the follow-up of the response to therapy. ImagesFigure 1Figure 2Figure 3Figure 4Figure 5Figure 6 PMID:25696121

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

    PubMed Central

    Koenig, Xaver; Kovar, Michael; Rubi, Lena; Mike, Agnes K.; Lukacs, Peter; Gawali, Vaibhavkumar S.; Todt, Hannes; Hilber, Karlheinz; Sandtner, Walter

    2013-01-01

    The plant alkaloid ibogaine has promising anti-addictive properties. Albeit not licenced as a therapeutic drug, and despite hints that ibogaine may perturb the heart rhythm, this alkaloid is used to treat drug addicts. We have recently reported that ibogaine inhibits human ERG (hERG) potassium channels at concentrations similar to the drugs affinity for several of its known brain targets. Thereby the drug may disturb the heart's electrophysiology. Here, to assess the drug's cardiac ion channel profile in more detail, we studied the effects of ibogaine and its congener 18-Methoxycoronaridine (18-MC) on various cardiac voltage-gated ion channels. We confirmed that heterologously expressed hERG currents are reduced by ibogaine in low micromolar concentrations. Moreover, at higher concentrations, the drug also reduced human Nav1.5 sodium and Cav1.2 calcium currents. Ion currents were as well reduced by 18-MC, yet with diminished potency. Unexpectedly, although blocking hERG channels, ibogaine did not prolong the action potential (AP) in guinea pig cardiomyocytes at low micromolar concentrations. Higher concentrations (≥ 10 μM) even shortened the AP. These findings can be explained by the drug's calcium channel inhibition, which counteracts the AP-prolonging effect generated by hERG blockade. Implementation of ibogaine's inhibitory effects on human ion channels in a computer model of a ventricular cardiomyocyte, on the other hand, suggested that ibogaine does prolong the AP in the human heart. We conclude that therapeutic concentrations of ibogaine have the propensity to prolong the QT interval of the electrocardiogram in humans. In some cases this may lead to cardiac arrhythmias. PMID:23707769

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

    PubMed

    Koenig, Xaver; Kovar, Michael; Rubi, Lena; Mike, Agnes K; Lukacs, Peter; Gawali, Vaibhavkumar S; Todt, Hannes; Hilber, Karlheinz; Sandtner, Walter

    2013-12-01

    The plant alkaloid ibogaine has promising anti-addictive properties. Albeit not licensed as a therapeutic drug, and despite hints that ibogaine may perturb the heart rhythm, this alkaloid is used to treat drug addicts. We have recently reported that ibogaine inhibits human ERG (hERG) potassium channels at concentrations similar to the drugs affinity for several of its known brain targets. Thereby the drug may disturb the heart's electrophysiology. Here, to assess the drug's cardiac ion channel profile in more detail, we studied the effects of ibogaine and its congener 18-Methoxycoronaridine (18-MC) on various cardiac voltage-gated ion channels. We confirmed that heterologously expressed hERG currents are reduced by ibogaine in low micromolar concentrations. Moreover, at higher concentrations, the drug also reduced human Nav1.5 sodium and Cav1.2 calcium currents. Ion currents were as well reduced by 18-MC, yet with diminished potency. Unexpectedly, although blocking hERG channels, ibogaine did not prolong the action potential (AP) in guinea pig cardiomyocytes at low micromolar concentrations. Higher concentrations (≥ 10 μM) even shortened the AP. These findings can be explained by the drug's calcium channel inhibition, which counteracts the AP-prolonging effect generated by hERG blockade. Implementation of ibogaine's inhibitory effects on human ion channels in a computer model of a ventricular cardiomyocyte, on the other hand, suggested that ibogaine does prolong the AP in the human heart. We conclude that therapeutic concentrations of ibogaine have the propensity to prolong the QT interval of the electrocardiogram in humans. In some cases this may lead to cardiac arrhythmias. PMID:23707769

  12. Dipyridamole cardiac imaging

    SciTech Connect

    Iskandrian, A.S.; Heo, J.; Askenase, A.; Segal, B.L.; Auerbach, N.

    1988-02-01

    Dipyridamole cardiac imaging is a useful alternative technique to exercise stress testing in the evaluation of patients with ischemic heart disease. Intravenous dipyridamole is still in the investigational phase, while oral dipyridamole is widely available. The hemodynamic effects of dipyridamole include an increase in coronary blood flow (due to coronary vasodilation) which is in excess of the increase in myocardial oxygen consumption and cardiac output. The disparity in the increase in coronary blood flow relative to the cardiac output results in an increase in myocardial thallium activity and an increase in the myocardial/background activity ratio. The quality of the thallium images is better or similar to that of exercise thallium images. The optimal dose of intravenous dipyridamole is 0.56 mg/kg, and of the oral dose it is 300 to 400 mg, although higher doses may be necessary in some patients. Analysis of the thallium images has been to a large extent based on visual inspection of the planar images. Delayed images are helpful to establish the nature of the perfusion abnormalities (transient or fixed). The process of redistribution is based on disparate rates of washout from the normal and abnormal zones. The sensitivity and specificity of dipyridamole thallium imaging, whether intravenous or oral, have been shown in a number of studies to be quite adequate and comparable to that achieved during exercise thallium imaging. Dipyridamole two-dimensional echocardiography has also been used in the detection of coronary artery disease; transient (new or worsening of preexisting) wall motion abnormalities have been found to be a specific marker of coronary artery disease. Transmural as well as regional coronary steal phenomena have been postulated as the mechanism for dipyridamole-induced regional wall motion abnormalities. 65 references.

  13. Assessment of Long-Term Climate Change Impacts on Agricultural Productivity in Eastern China Using High-Resolution Regional Climate Model Output

    NASA Astrophysics Data System (ADS)

    Chavas, D. R.; Izaurralde, C.; Thomson, A.

    2008-12-01

    Increasing atmospheric greenhouse gas concentrations are expected to induce significant climate change over the next century and beyond, but the impacts on society remain highly uncertain. This work utilizes high-resolution regional climate model output to assess potential climate change impacts on the productivity of five major crops in eastern China: canola, corn, potato, rice, and winter wheat. In addition to determining domain-wide trends, the objective is to identify vulnerable and emergent regions under future climate conditions, defined as having a greater than 10 percent decrease and increase in productivity, respectively. Data from the ICTP RegCM3 regional climate model for baseline (1961-1990) and future (2071-2100) periods under A2 scenario conditions are used as input in the EPIC agro-ecosystem simulation model in the domain [30N, 108E] to [42N, 123E]. Simulations are performed with and without the enhanced CO2 fertilization effect. Results indicate that aggregate potential productivity (i.e. if the crop is grown everywhere) increases 6.5 percent for rice, 8.3 percent for canola, 18.6 percent for corn, 22.9 percent for potato, and 24.9 percent for winter wheat, although with significant spatial variability for each crop. However, absent the enhanced CO2 fertilization effect, potential productivity declines in all cases ranging from 2.5-12 percent. Interannual yield variability remains constant or declines in all cases except rice. Climate variables are found to be more significant drivers of simulated yield changes than changes in soil properties, except in the case of potato production in the northwest where the effects of wind erosion are more significant. Overall, in the future period corn and winter wheat benefit significantly in the North China Plain, rice remains dominant in the southeast and emerges in the northeast, potato and corn yields become viable in the northwest, and potato yields suffer in the southwest with no other crop emerging as a clear beneficiary from among those simulated in this study.

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

    NASA Astrophysics Data System (ADS)

    Baptista, M.; Teles, P.; Cardoso, G.; Vaz, P.

    2014-11-01

    Over the last decade, there was a substantial increase in the number of interventional cardiology procedures worldwide, and the corresponding ionizing radiation doses for both the medical staff and patients became a subject of concern. Interventional procedures in cardiology are normally very complex, resulting in long exposure times. Also, these interventions require the operator to work near the patient and, consequently, close to the primary X-ray beam. Moreover, due to the scattered radiation from the patient and the equipment, the medical staff is also exposed to a non-uniform radiation field that can lead to a significant exposure of sensitive body organs and tissues, such as the eye lens, the thyroid and the extremities. In order to better understand the spatial variation of the dose and dose rate distributions during an interventional cardiology procedure, the dose distribution around a C-arm fluoroscopic system, in operation in a cardiac cath lab at Portuguese Hospital, was estimated using both Monte Carlo (MC) simulations and dosimetric measurements. To model and simulate the cardiac cath lab, including the fluoroscopic equipment used to execute interventional procedures, the state-of-the-art MC radiation transport code MCNPX 2.7.0 was used. Subsequently, Thermo-Luminescent Detector (TLD) measurements were performed, in order to validate and support the simulation results obtained for the cath lab model. The preliminary results presented in this study reveal that the cardiac cath lab model was successfully validated, taking into account the good agreement between MC calculations and TLD measurements. The simulated results for the isodose curves related to the C-arm fluoroscopic system are also consistent with the dosimetric information provided by the equipment manufacturer (Siemens). The adequacy of the implemented computational model used to simulate complex procedures and map dose distributions around the operator and the medical staff is discussed, in view of the optimization principle (and the associated ALARA objective), one of the pillars of the international system of radiological protection.

  15. [Multiple cardiac rhabdomyoma associated to intrauterine death].

    PubMed

    Morales-Quispe, Jorge A; Espínola-Zavaleta, Nilda; Caballero-Caballero, Rocío; Brunner-Cruz, Guadalupe; Uribe Alcántara, Sergio

    2011-01-01

    Rhabdomyoma is the most common cardiac tumor detected during fetal life and childhood; nevertheless its incidence is very low. This is a histologically benign tumor, but in some cases may cause hemodynamic repercussion with date of low cardiac output, arrhythmias and exceptionally intrauterine death as occurred in our case, which was detected by obstetric ultrasound and fetal echocardiogram and corroborated by histological study. PMID:21975236

  16. Myocardial Dysfunction and Shock after Cardiac Arrest

    PubMed Central

    Jentzer, Jacob C.; Chonde, Meshe D.; Dezfulian, Cameron

    2015-01-01

    Postarrest myocardial dysfunction includes the development of low cardiac output or ventricular systolic or diastolic dysfunction after cardiac arrest. Impaired left ventricular systolic function is reported in nearly two-thirds of patients resuscitated after cardiac arrest. Hypotension and shock requiring vasopressor support are similarly common after cardiac arrest. Whereas shock requiring vasopressor support is consistently associated with an adverse outcome after cardiac arrest, the association between myocardial dysfunction and outcomes is less clear. Myocardial dysfunction and shock after cardiac arrest develop as the result of preexisting cardiac pathology with multiple superimposed insults from resuscitation. The pathophysiology involves cardiovascular ischemia/reperfusion injury and cardiovascular toxicity from excessive levels of inflammatory cytokine activation and catecholamines, among other contributing factors. Similar mechanisms occur in myocardial dysfunction after cardiopulmonary bypass, in sepsis, and in stress-induced cardiomyopathy. Hemodynamic stabilization after resuscitation from cardiac arrest involves restoration of preload, vasopressors to support arterial pressure, and inotropic support if needed to reverse the effects of myocardial dysfunction and improve systemic perfusion. Further research is needed to define the role of postarrest myocardial dysfunction on cardiac arrest outcomes and identify therapeutic strategies. PMID:26421284

  17. Robotic cardiac surgery: an anaesthetic challenge.

    PubMed

    Wang, Gang; Gao, Changqing

    2014-08-01

    Robotic cardiac surgery with the da Vinci robotic surgical system offers the benefits of a minimally invasive procedure, including a smaller incision and scar, reduced risk of infection, less pain and trauma, less bleeding and blood transfusion requirements, shorter hospital stay and decreased recovery time. Robotic cardiac surgery includes extracardiac and intracardiac procedures. Extracardiac procedures are often performed on a beating heart. Intracardiac procedures require the aid of peripheral cardiopulmonary bypass via a minithoracotomy. Robotic cardiac surgery, however, poses challenges to the anaesthetist, as the obligatory one-lung ventilation (OLV) and CO2 insufflation may reduce cardiac output and increase pulmonary vascular resistance, potentially resulting in hypoxaemia and haemodynamic compromise. In addition, surgery requires appropriate positioning of specialised cannulae such as an endopulmonary vent, endocoronary sinus catheter, and endoaortic clamp catheter under the guidance of transoesophageal echocardiography. Therefore, cardiac anaesthetists should have a working knowledge of these systems, OLV and haemodynamic support. PMID:24958894

  18. A cortical potential reflecting cardiac function

    PubMed Central

    Gray, Marcus A.; Taggart, Peter; Sutton, Peter M.; Groves, David; Holdright, Diana R.; Bradbury, David; Brull, David; Critchley, Hugo D.

    2007-01-01

    Emotional trauma and psychological stress can precipitate cardiac arrhythmia and sudden death through arrhythmogenic effects of efferent sympathetic drive. Patients with preexisting heart disease are particularly at risk. Moreover, generation of proarrhythmic activity patterns within cerebral autonomic centers may be amplified by afferent feedback from a dysfunctional myocardium. An electrocortical potential reflecting afferent cardiac information has been described, reflecting individual differences in interoceptive sensitivity (awareness of one's own heartbeats). To inform our understanding of mechanisms underlying arrhythmogenesis, we extended this approach, identifying electrocortical potentials corresponding to the cortical expression of afferent information about the integrity of myocardial function during stress. We measured changes in cardiac response simultaneously with electroencephalography in patients with established ventricular dysfunction. Experimentally induced mental stress enhanced cardiovascular indices of sympathetic activity (systolic blood pressure, heart rate, ventricular ejection fraction, and skin conductance) across all patients. However, the functional response of the myocardium varied; some patients increased, whereas others decreased, cardiac output during stress. Across patients, heartbeat-evoked potential amplitude at left temporal and lateral frontal electrode locations correlated with stress-induced changes in cardiac output, consistent with an afferent cortical representation of myocardial function during stress. Moreover, the amplitude of the heartbeat-evoked potential in the left temporal region reflected the proarrhythmic status of the heart (inhomogeneity of left ventricular repolarization). These observations delineate a cortical representation of cardiac function predictive of proarrhythmic abnormalities in cardiac repolarization. Our findings highlight the dynamic interaction of heart and brain in stress-induced cardiovascular morbidity. PMID:17420478

  19. The Localization and Characterization of Ischemic Scars in relation to the Infarct Related Coronary Artery Assessed by Cardiac Magnetic Resonance and a Novel Automatic Postprocessing Method

    PubMed Central

    Woie, Leik; Engan, Kjersti; Eftestl, Trygve; Larsen, Alf Inge; rn, Stein

    2015-01-01

    Aims. The correspondence between the localization and morphology of ischemic scars and the infarct related artery (IRA) by use of cardiac magnetic resonance imaging and a novel automatic postprocessing method. Methods and Results. Thirty-four patients with one-year-old single IRA myocardial infarction were examined. Endocardium, epicardium, and the point where right and left ventricles are coinciding were manually marked. All measurements were automatically assessed by the method. The following are results with manual assessments of scar properties in parenthesis: mean scar size (FWHM criterion): 7.8 5.5 as %LV (17.4 8.6%); mean endocardial extent of infarction: 44 26 (124 47); mean endocardial extent of infarction as %LV circumference: 9.7 7.0% (34.6 13.0%); and mean transmurality: 52 20% of LV wall thickness (77 23%). Scars located in segments 1, 2, 7, 8, 13, and 14 by use of the automatic method were 96100% specific for LAD occlusion. The highest specificities of RCA and LCX occlusions were segment 4 with 93% and segment 6 with 64%, respectively. The scar localization assessed automatically or manually was without major differences. Conclusion. The automatic method is applicable and able to assess localization, size, transmurality, and endocardial extent of ischemic scars. PMID:26543661

  20. [Cardiac rhabdomyomas].

    PubMed

    Jacob, J L; Hassen Sobrinho, S; Lorga, A M; Suzigan, S; Braile, D M

    1991-01-01

    Case report of cardiac rhabdomyoma in one two days old infant with important cyanosis and respiratory insufficiency with evolution to death in few hours. The radiologic feature was a great enlargement of the heart and the electrocardiographic study showed left branch block. The two-dimensional echocardiography study showed multiple intracavitary tumours in both ventricles and in the right atrium. These features were confirmed in the post-mortem study. The microscopic study of the tumors showed proliferation of the spider cells, and vacuolation with the presence glycogen. The diagnosis of cardiac rhabdomyoma was confirmed. The brain and the kidney were not studied for the diagnosis of tuberous sclerosis or kidney tumors. It is very important the early diagnosis by echocardiography, due to the possibility of surgical resection of the intracavitary tumors that cause severe obstruction to the blood flow. PMID:1872712

  1. Assessment of global cardiac uptake of Radiolabeled Iron Oxide Nanoparticles in Apolipoprotein E-Deficient Mice: implications for imaging cardiovascular inflammation

    PubMed Central

    de Barros, Andr Lus Branco; Chacko, Ann-Marie; Mikitsh, John L.; Zaki, Ajlan Al; Salavati, Ali; Saboury, Babak; Tsourkas, Andrew; Alavi, Abass

    2014-01-01

    Purpose Atherosclerosis is a leading cause of death in industrialized countries and is characterized by the accumulation of lipids and inflammatory cells, including macrophages, in blood vessel walls. Therefore, the ability to image macrophages could help identify plaques that are precursors of acute thrombotic events. Previous research has shown that long-circulating, nanoparticles could be used to detect macrophages within atherosclerotic plaques of the aorta. By conducting this study, we investigated whether global cardiac uptake of radiolabeled nanoparticles could allow assessment of total macrophage burden in the coronary arteries. Procedures Dextran-coated Iron Oxide Nanoparticles (IONPs) were labeled with iodine-125 via Bolton-Hunter (SHPP) method. IONPs were characterized by means of dynamic light scattering and transmission electronic microscopy. Biodistribution studies were performed in healthy and atherosclerotic mice. Additionally, digital autoradiography of hearts from both healthy and atherosclerotic mice was performed to assess regional and global atherosclerotic burden. Results The [125I]IONPs exhibited high radiolabel stability and long blood circulation, which eventually led to high heart uptake in apoE ?/? mice when compared with healthy controls. Furthermore, digital autoradiography showed substantially enhanced emission of signals from the hearts of atherosclerotic mice, while no or minimal cardiac signals were detected in healthy mice. Conclusions This preparation showed adequate physical-chemical properties for in vivo studies, such as small size (~30 nm), good radiolabel stability, and long circulation time. There was also significant accumulation in the heart of apoE?/? mice compared with that of healthy control animals. These findings suggest that radiolabeled dextran-coated iron oxide nanoparticles may have potential to become a useful tool to detect macrophages in the atherosclerosis plaques of coronary arteries; however, these preliminary findings should be confirmed by further studies in a larger scale in various atherosclerosis models. PMID:24297372

  2. Cardiac lipoma

    PubMed Central

    Ismail, Imtiaz; Al-Khafaji, Khalid; Mutyala, Monica; Aggarwal, Saurabh; Cotter, William; Hakim, Hosam; Khosla, Sandeep; Arora, Rohit

    2015-01-01

    Lipomas of the heart are encapsulated tumors that are composed primarily of mature fat cells. Cardiac lipomas can originate either from subendocardium (approximately 50%), subpericardium (25%), or from the myocardium (25%) and may be located more frequently in left ventricle or right atrium. We report a 74-year-old female who presented with dyspnea on exertion and was found to have 55 cm mass occupying most of the right atrium on a transesophageal echocardiogram. PMID:26486106

  3. Bayesian Sensitivity Analysis of a Cardiac Cell Model Using a Gaussian Process Emulator

    PubMed Central

    Chang, Eugene T Y; Strong, Mark; Clayton, Richard H

    2015-01-01

    Models of electrical activity in cardiac cells have become important research tools as they can provide a quantitative description of detailed and integrative physiology. However, cardiac cell models have many parameters, and how uncertainties in these parameters affect the model output is difficult to assess without undertaking large numbers of model runs. In this study we show that a surrogate statistical model of a cardiac cell model (the Luo-Rudy 1991 model) can be built using Gaussian process (GP) emulators. Using this approach we examined how eight outputs describing the action potential shape and action potential duration restitution depend on six inputs, which we selected to be the maximum conductances in the Luo-Rudy 1991 model. We found that the GP emulators could be fitted to a small number of model runs, and behaved as would be expected based on the underlying physiology that the model represents. We have shown that an emulator approach is a powerful tool for uncertainty and sensitivity analysis in cardiac cell models. PMID:26114610

  4. Power output measurement during treadmill cycling.

    PubMed

    Coleman, D A; Wiles, J D; Davison, R C R; Smith, M F; Swaine, I L

    2007-06-01

    The study aim was to consider the use of a motorised treadmill as a cycling ergometry system by assessing predicted and recorded power output values during treadmill cycling. Fourteen male cyclists completed repeated cycling trials on a motorised treadmill whilst riding their own bicycle fitted with a mobile ergometer. The speed, gradient and loading via an external pulley system were recorded during 20-s constant speed trials and used to estimate power output with an assumption about the contribution of rolling resistance. These values were then compared with mobile ergometer measurements. To assess the reliability of measured power output values, four repeated trials were conducted on each cyclist. During level cycling, the recorded power output was 257.2 +/- 99.3 W compared to the predicted power output of 258.2 +/- 99.9 W (p > 0.05). For graded cycling, there was no significant difference between measured and predicted power output, 268.8 +/- 109.8 W vs. 270.1 +/- 111.7 W, p > 0.05, SEE 1.2 %. The coefficient of variation for mobile ergometer power output measurements during repeated trials ranged from 1.5 % (95 % CI 1.2 - 2.0 %) to 1.8 % (95 % CI 1.5 - 2.4 %). These results indicate that treadmill cycling can be used as an ergometry system to assess power output in cyclists with acceptable accuracy. PMID:17497583

  5. Adaptive detection of missed text areas in OCR outputs: application to the automatic assessment of OCR quality in mass digitization projects

    NASA Astrophysics Data System (ADS)

    Ben Salah, Ahmed; Ragot, Nicolas; Paquet, Thierry

    2013-01-01

    The French National Library (BnF*) has launched many mass digitization projects in order to give access to its collection. The indexation of digital documents on Gallica (digital library of the BnF) is done through their textual content obtained thanks to service providers that use Optical Character Recognition softwares (OCR). OCR softwares have become increasingly complex systems composed of several subsystems dedicated to the analysis and the recognition of the elements in a page. However, the reliability of these systems is always an issue at stake. Indeed, in some cases, we can find errors in OCR outputs that occur because of an accumulation of several errors at different levels in the OCR process. One of the frequent errors in OCR outputs is the missed text components. The presence of such errors may lead to severe defects in digital libraries. In this paper, we investigate the detection of missed text components to control the OCR results from the collections of the French National Library. Our verification approach uses local information inside the pages based on Radon transform descriptors and Local Binary Patterns descriptors (LBP) coupled with OCR results to control their consistency. The experimental results show that our method detects 84.15% of the missed textual components, by comparing the OCR ALTO files outputs (produced by the service providers) to the images of the document.

  6. Cardiac Surgery

    PubMed Central

    Weisse, Allen B.

    2011-01-01

    Well into the first decades of the 20th century, medical opinion held that any surgical attempts to treat heart disease were not only misguided, but unethical. Despite such reservations, innovative surgeons showed that heart wounds could be successfully repaired. Then, extracardiac procedures were performed to correct patent ductus arteriosus, coarctation of the aorta, and tetralogy of Fallot. Direct surgery on the heart was accomplished with closed commissurotomy for mitral stenosis. The introduction of the heart-lung machine and cardiopulmonary bypass enabled the surgical treatment of other congenital and acquired heart diseases. Advances in aortic surgery paralleled these successes. The development of coronary artery bypass grafting greatly aided the treatment of coronary heart disease. Cardiac transplantation, attempts to use the total artificial heart, and the application of ventricular assist devices have brought us to the present day. Although progress in the field of cardiovascular surgery appears to have slowed when compared with the halcyon times of the past, substantial challenges still face cardiac surgeons. It can only be hoped that sufficient resources and incentive can carry the triumphs of the 20th century into the 21st. This review covers past developments and future opportunities in cardiac surgery. PMID:22163121

  7. Cardiac mechanics: Physiological, clinical, and mathematical considerations

    NASA Technical Reports Server (NTRS)

    Mirsky, I. (Editor); Ghista, D. N.; Sandler, H.

    1974-01-01

    Recent studies concerning the basic physiological and biochemical principles underlying cardiac muscle contraction, methods for the assessment of cardiac function in the clinical situation, and mathematical approaches to cardiac mechanics are presented. Some of the topics covered include: cardiac ultrastructure and function in the normal and failing heart, myocardial energetics, clinical applications of angiocardiography, use of echocardiography for evaluating cardiac performance, systolic time intervals in the noninvasive assessment of left ventricular performance in man, evaluation of passive elastic stiffness for the left ventricle and isolated heart muscle, a conceptual model of myocardial infarction and cardiogenic shock, application of Huxley's sliding-filament theory to the mechanics of normal and hypertrophied cardiac muscle, and a rheological modeling of the intact left ventricle. Individual items are announced in this issue.

  8. Estimates of embodied global energy and air-emission intensities of Japanese products for building a Japanese input-output life cycle assessment database with a global system boundary.

    PubMed

    Nansai, Keisuke; Kondo, Yasushi; Kagawa, Shigemi; Suh, Sangwon; Nakajima, Kenichi; Inaba, Rokuta; Tohno, Susumu

    2012-08-21

    To build a life cycle assessment (LCA) database of Japanese products embracing their global supply chains in a manner requiring lower time and labor burdens, this study estimates the intensity of embodied global environmental burden for commodities produced in Japan. The intensity of embodied global environmental burden is a measure of the environmental burden generated globally by unit production of the commodity and can be used as life cycle inventory data in LCA. The calculation employs an input-output LCA method with a global link input-output model that defines a global system boundary grounded in a simplified multiregional input-output framework. As results, the intensities of embodied global environmental burden for 406 Japanese commodities are determined in terms of energy consumption, greenhouse-gas emissions (carbon dioxide, methane, nitrous oxide, perfluorocarbons, hydrofluorocarbons, sulfur hexafluoride, and their summation), and air-pollutant emissions (nitrogen oxide and sulfur oxide). The uncertainties in the intensities of embodied global environmental burden attributable to the simplified structure of the global link input-output model are quantified using Monte Carlo simulation. In addition, by analyzing the structure of the embodied global greenhouse-gas intensities we characterize Japanese commodities in the context of LCA embracing global supply chains. PMID:22881452

  9. Cardiac cone-beam CT

    SciTech Connect

    Manzke, Robert . E-mail: robert.manzke@philips.com

    2005-10-15

    This doctoral thesis addresses imaging of the heart with retrospectively gated helical cone-beam computed tomography (CT). A thorough review of the CT reconstruction literature is presented in combination with a historic overview of cardiac CT imaging and a brief introduction to other cardiac imaging modalities. The thesis includes a comprehensive chapter about the theory of CT reconstruction, familiarizing the reader with the problem of cone-beam reconstruction. The anatomic and dynamic properties of the heart are outlined and techniques to derive the gating information are reviewed. With the extended cardiac reconstruction (ECR) framework, a new approach is presented for the heart-rate-adaptive gated helical cardiac cone-beam CT reconstruction. Reconstruction assessment criteria such as the temporal resolution, the homogeneity in terms of the cardiac phase, and the smoothness at cycle-to-cycle transitions are developed. Several reconstruction optimization approaches are described: An approach for the heart-rate-adaptive optimization of the temporal resolution is presented. Streak artifacts at cycle-to-cycle transitions can be minimized by using an improved cardiac weighting scheme. The optimal quiescent cardiac phase for the reconstruction can be determined automatically with the motion map technique. Results for all optimization procedures applied to ECR are presented and discussed based on patient and phantom data. The ECR algorithm is analyzed for larger detector arrays of future cone-beam systems throughout an extensive simulation study based on a four-dimensional cardiac CT phantom. The results of the scientific work are summarized and an outlook proposing future directions is given. The presented thesis is available for public download at www.cardiac-ct.net.

  10. Partial scan artifact reduction (PSAR) for the assessment of cardiac perfusion in dynamic phase-correlated CT

    SciTech Connect

    Stenner, Philip; Schmidt, Bernhard; Bruder, Herbert; Allmendinger, Thomas; Haberland, Ulrike; Flohr, Thomas; Kachelriess, Marc

    2009-12-15

    Purpose: Cardiac CT achieves its high temporal resolution by lowering the scan range from 2{pi} to {pi} plus fan angle (partial scan). This, however, introduces CT-value variations, depending on the angular position of the {pi} range. These partial scan artifacts are of the order of a few HU and prevent the quantitative evaluation of perfusion measurements. The authors present the new algorithm partial scan artifact reduction (PSAR) that corrects a dynamic phase-correlated scan without a priori information. Methods: In general, a full scan does not suffer from partial scan artifacts since all projections in [0, 2{pi}] contribute to the data. To maintain the optimum temporal resolution and the phase correlation, PSAR creates an artificial full scan p{sub n}{sup AF} by projectionwise averaging a set of neighboring partial scans p{sub n}{sup P} from the same perfusion examination (typically N{approx_equal}30 phase-correlated partial scans distributed over 20 s and n=1,...,N). Corresponding to the angular range of each partial scan, the authors extract virtual partial scans p{sub n}{sup V} from the artificial full scan p{sub n}{sup AF}. A standard reconstruction yields the corresponding images f{sub n}{sup P}, f{sub n}{sup AF}, and f{sub n}{sup V}. Subtracting the virtual partial scan image f{sub n}{sup V} from the artificial full scan image f{sub n}{sup AF} yields an artifact image that can be used to correct the original partial scan image: f{sub n}{sup C}=f{sub n}{sup P}-f{sub n}{sup V}+f{sub n}{sup AF}, where f{sub n}{sup C} is the corrected image. Results: The authors evaluated the effects of scattered radiation on the partial scan artifacts using simulated and measured water phantoms and found a strong correlation. The PSAR algorithm has been validated with a simulated semianthropomorphic heart phantom and with measurements of a dynamic biological perfusion phantom. For the stationary phantoms, real full scans have been performed to provide theoretical reference values. The improvement in the root mean square errors between the full and the partial scans with respect to the errors between the full and the corrected scans is up to 54% for the simulations and 90% for the measurements. Conclusions: The phase-correlated data now appear accurate enough for a quantitative analysis of cardiac perfusion.

  11. An echocardiographic assessment of cardiac morphology and common ECG findings in teenage professional soccer players: reference ranges for use in screening

    PubMed Central

    Somauroo, J; Pyatt, J; Jackson, M; Perry, R; Ramsdale, D

    2001-01-01

    OBJECTIVETo assess physiological cardiac adaptation in adolescent professional soccer players.?SUBJECTS AND DESIGNOver a 32month period 172teenage soccer players were screened by echocardiography and ECG at a tertiary referral cardiothoracic centre. They were from six professional soccer teams in the north west of England, competing in the English Football League. One was excluded because of an atrial septal defect. The median age of the 171players assessed was 16.7years (5th to 95th centile range: 14-19) and median body surface area 1.68m2 (1.39-2.06m2).?MAIN OUTCOME MEASURESStandard echocardiographic measurements were compared with predicted mean, lower, and upper limits in a cohort of normal controls after matching for age and surface area. Univariate regression analysis was used to assess the correlation between echocardiographic variables and the age and surface area of the soccer player cohort. ECG findings were also assessed.?RESULTSAll mean echocardiographic variables were greater than predicted for age and surface area matched controls (p<0.001). All variables except left ventricular septal and posterior wall thickness showed a modest linear correlation with surface area (r=0.2 to 0.4,p<0.001); however, left ventricular mass was the only variable that was significantly correlated with age (r=0.2, p<0.01). Only six players (3.5%) had structural anomalies, none of which required further evaluation. All had normal left ventricular systolic function. Sinus bradycardia was found in 65(39%). The Solokow-Lyon voltage criteria for left ventricular hypertrophy were present in 85(50%) and the Romhilt-Estes points score (five or more) in 29(17%). Repolarisation changes were present in 19(11%), mainly in the inferior leads.?CONCLUSIONSChamber dimensions, left ventricular wall thickness and mass, and aortic root size were all greater than predicted for controls after matching for age and surface area. Sinus bradycardia and the ECG criteria for left ventricular hypertrophy were common but there was poor correlation with echocardiographic left ventricular hypertrophy. The type of hypertrophy found reflected the combined endurance and strength based training undertaken.???Keywords: cardiac morphology; professional soccer players; echocardiography; ECG findings PMID:11359746

  12. A Geospatial Assessment of Transport Distance and Survival to Discharge In Out Of Hospital Cardiac Arrest Patients: Implications for Resuscitation Centers

    PubMed Central

    Cudnik, Michael T.; Schmicker, Robert H.; Vaillancourt, Christian; Newgard, Craig D.; Christenson, James M.; Davis, Daniel P.; Lowe, Robert A.

    2010-01-01

    OBJECTIVES National leaders have suggested that patients with an out-of-hospital cardiac arrest (OOHCA) may benefit from transport to specialized hospitals. We sought to assess the survival of OOHCA patients by transport distance and hospital proximity. METHODS Prospective, cohort study of OOHCA patients in 11 Resuscitation Outcomes Consortium (ROC) sites across North America. Transport distance and hospital proximity was calculated using weighted centroid of census tract location by Geographic Information Systems (GIS). Patients were stratified into quartiles based on transport distance to the receiving hospital calculated via GIS. Descriptive statistics were used to describe characteristics by transport distance and to compare proximity to other hospitals. Multivariate logistic regression was used to evaluate the impact of transport distance on survival. RESULTS 26,628 patients were identified, 7,540 (28%) were transported by EMS and included in the final analysis. The median transport time was 6.3 minutes (IQR 5.4); the median transport distance being 2.4 miles (3.9 km). Most patients were taken to the closest hospital (71.7%; N=5,412). However, unadjusted survival to discharge was lower for those taken to the closest compared to further hospitals (12.1% vs. 16.5%) despite similar patient characteristics. Transport distance was not associated with survival on logistic analysis (OR 1.00; 95% CI 0.991.01). CONCLUSIONS Survival to discharge was higher in OOHCA patients taken to hospitals located further than the closest hospital while transport distance was not associated with survival. This suggests that longer transport distance/time might not adversely affect outcome. Further studies are needed to inform policy decisions regarding best destination post cardiac arrest PMID:20122779

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

    PubMed Central

    Rao, Chenfei; Bongiovanni, Tasce; Li, Xi; Gao, Huawei; Zhang, Heng; Li, Jing; Zhao, Yan; Yuan, Xin; Hua, Kun; Hu, Shengshou; Krumholz, Harlan M; Jiang, Lixin; Zheng, Zhe

    2016-01-01

    Introduction Complex coronary artery disease (left main and three-vessel disease) carries high risks of adverse events and cost burden. However, in China, little is known about which patients are directed toward which treatment strategies and what outcomes are being achieved. Methods and analysis Using the China PEACE (Patient-centered Evaluative Assessment of Cardiac Events) research network, this prospective study of three-Vessel Disease, the China PEACE-3VD study, has a plan to consecutively register over 4000 patients with a diagnosis of 3VD and/or left-main disease by elective coronary angiography at 24 large cardiovascular centres in China. We centrally conducted medical record abstraction and SYNTAX Score calculation for all registered patients. The sites invited patients to the prospective cohort, and conducted 1-year follow-up on major events, including cardiac events, symptoms, secondary prevention and quality of life. The estimated entire sample size of eligible patients of 4000 was determined based on both feasibility and consideration of adequate statistical precision for describing the treatment decisions, guidelines adherence and appropriateness of treatment for patients with complex coronary artery diseases. The study is designed to investigate patient, clinician and hospital factors associated with each treatment strategy (percutaneous coronary intervention, coronary artery bypass grafting or medical therapy) as well as appropriateness of treatment choice, current guideline compliance and patient-reported outcomes for patients with complex coronary artery disease in large cardiovascular centres in China, as a foundation for enhanced knowledge in the field and to assist quality improvement initiatives. Ethics and dissemination The study protocol was approved by the ethics committee at the China National Center for Cardiovascular Diseases. Findings will be shared with participating hospitals, policymakers and the academic community, to promote quality monitoring, quality improvement and the efficient allocation, and use of coronary revascularisation procedures in China. Trial registration number NCT01625312; Pre-results PMID:26880670

  14. Linear output nitinol engine

    SciTech Connect

    Banks, R.M.

    1986-01-14

    This patent describes a linear output nitinol engine consisting of a number of integrated communicating parts. The engine has an external support framework which is described in detail. The patent further describes a wire transport mechanism, a pair of linkage levers with a loom secured to them, a number of nitinol wires strung between the looms, and a power takeoff block secured to the linkage levers. A pulley positioned in a flip-flop supporting bracket and a power takeoff modality including a tension member connected to a power output cable in order to provide linear power output transmission is described. A method for biasing the timing and the mechanism for timing the synchronization of the throw over arms and the flip-flop of the pulley are also described.

  15. High-output heart failure secondary to arteriovenous fistula.

    PubMed

    Stern, Adam B; Klemmer, Philip J

    2011-01-01

    In the hemodialysis patient population, a surgically created arteriovenous fistula is the preferred vascular access option. Development of high-output heart failure may be an underappreciated complication in patients who have undergone this procedure. When a large proportion of arterial blood is shunted from the left-sided circulation to the right-sided circulation via the fistula, the increase in preload can lead to increased cardiac output. Over time, the demands of an increased workload may lead to cardiac hypertrophy and eventual heart failure. Patients may present with the usual signs of high-output heart failure including tachycardia, elevated pulse pressure, hyperkinetic precordium, and jugular venous distension. Typically, the AV fistula is quite large and is likely located in the upper arm, more proximal to the heart. Routine access flow monitoring should demonstrate blood flows (Qa) >2000 ML/min. Echocardiogram may reveal either a low or high left ventricular ejection fraction, and right-heart catheterization demonstrates an elevated cardiac output with a low to normal systemic vascular resistance. When addressing the problem of high-output heart failure, the nephrologist is faced with the dilemma of preventing progression of heart failure at the expense of loss of vascular access. Nevertheless, treatment should be directed at correcting the underlying problem by surgical banding or ligation of the fistula. PMID:21223485

  16. The ethical and legal views of physicians regarding deactivation of cardiac implantable electrical devices: a quantitative assessment

    PubMed Central

    Kramer, Daniel B.; Kesselheim, Aaron S.; Brock, Dan W.; Maisel, William H.

    2010-01-01

    Background Despite the high prevalence of pacemakers and implantable cardioverter-defibrillators, little is known about physician views surrounding the ethical and legal aspects of managing these devices at the end-of-life. Objective To identify physician experiences and views surrounding the ethical and legal aspects of managing cardiac devices at the end-of-life. Methods Survey questions were administered to internal medicine physicians and subspecialists at a tertiary care center. Physicians were surveyed about their clinical experience, legal knowledge, and ethical beliefs relating to the withdrawal of PM and ICD therapy in comparison to other life-sustaining therapies. Results Responses were obtained from 185 physicians. Compared to PMs and ICDs, physicians more often reported having participated in the withdrawal or removal of mechanical ventilation (86.1% vs. 33.9%, P<0.0001), dialysis (60.6% vs. 33.9%, P<0.001), and feeding tubes (73.8% vs. 33.9%, P<0.0001). Physicians were consistently less comfortable discussing cessation of PMs and ICDs compared to other life-sustaining therapies (P<0.005). Only 65% of physicians correctly identified the legal status of euthanasia in the US, and 20% accurately reported the legal status of physician-assisted suicide in the US. Compared to deactivation of an ICD, physicians more often characterized deactivation of a PM in a pacemaker-dependent patient as physician-assisted suicide (19% vs. 10%, P=0.027) or euthanasia (9% vs. 1%, P<0.001). Conclusions In this single-center study, internists were less comfortable discussing cessation of PM and ICD therapy compared to other life-sustaining therapies and lacked experience with this practice. Education regarding the legal and ethical parameters of device deactivation is needed. PMID:20650332

  17. Time course of circulatory and metabolic recovery of cat brain after cardiac arrest assessed by perfusion- and diffusion-weighted imaging and MR-spectroscopy.

    PubMed

    Krep, Henning; Bttiger, Bernd W; Bock, Christian; Kerskens, Christian M; Radermacher, Bernd; Fischer, Matthias; Hoehn, Mathias; Hossmann, Konstantin Alexander

    2003-09-01

    Brain recovery after cardiac arrest (CA) was assessed in cats using arterial spin tagging perfusion-weighted imaging (PWI), diffusion-weighted imaging (DWI), and 1H-spectroscopy (1H-MRS). Cerebral reperfusion and metabolic recovery was monitored in the cortex and in basal ganglia for 6 h after cardiopulmonary resuscitation (CPR). Furthermore, the effects of an hypertonic/hyperoncotic solution (7.5% NaCl/6% hydroxyl ethyl starch, HES) and a tissue-type plasminogen activator (TPA), applied during CPR, were assessed on brain recovery. CA and CPR were carried out in the MR scanner by remote control. CA for 15-20 min was induced by electrical fibrillation of the heart, followed by CPR using a pneumatic vest. PWI after successful CPR revealed initial cerebral hyperperfusion followed by delayed hypoperfusion. Initial cerebral recirculation was improved after osmotic treatment. Osmotic and thrombolytic therapy were ineffective in ameliorating delayed hypoperfusion. Calculation of the apparent diffusion coefficient (ADC) from DWI demonstrated complete recovery of ion and water homeostasis in all animals. 1H-MRS measurements of lactate suggested an extended preservation of post-ischaemic anaerobic metabolism after TPA treatment. The combination of noninvasive MR techniques is a powerful tool for the evaluation of therapeutical strategies on circulatory and metabolic cerebral recovery after experimental cerebral ischaemia. PMID:12969612

  18. Cardiac Vagal Regulation and Early Peer Status

    ERIC Educational Resources Information Center

    Graziano, Paulo A.; Keane, Susan P.; Calkins, Susan D.

    2007-01-01

    A sample of 341 5 1/2-year-old children participating in an ongoing longitudinal study was the focus of a study on the relation between cardiac vagal regulation and peer status. To assess cardiac vagal regulation, resting measures of respiratory sinus arrhythmia (RSA) and RSA change (suppression) to 3 cognitively and emotionally challenging tasks…

  19. Cardiac Vagal Regulation and Early Peer Status

    ERIC Educational Resources Information Center

    Graziano, Paulo A.; Keane, Susan P.; Calkins, Susan D.

    2007-01-01

    A sample of 341 5 1/2-year-old children participating in an ongoing longitudinal study was the focus of a study on the relation between cardiac vagal regulation and peer status. To assess cardiac vagal regulation, resting measures of respiratory sinus arrhythmia (RSA) and RSA change (suppression) to 3 cognitively and emotionally challenging tasks

  20. Radionuclide ventriculography for assessment of absolute right and left ventricular volumes in children

    SciTech Connect

    Parrish, M.D.; Graham, T.P. Jr.; Born, M.L.; Jones, J.P.; Boucek, R.J. Jr.; Partain, C.L.

    1982-10-01

    Absolute right and left ventricular volumes and cardiac output were determined from the equilibrium radionuclide angiogram in 26 children, ages 3 months to 18 years, with diverse types of heart disease. We validated these results by comparing them with left ventricular (20 patients) and right ventricular (16 patients) cineangiographic volumes and cardiac output. Radionuclide volumes and cardiac outputs were determined in two ways: by a geometric method (area-length for left ventricle, Simpson's rule for right ventricle) and by a count-based method (correcting ventricular regional counts for frame duration, acquisition time, venous blood counts and attenuation). Both methods for estimating left ventricular end-diastolic volume compared favorably with cineangiography (correlation coefficients greater than 0.90). The count-based method also correlated well for the right ventricle. End-systolic measurements were not possible. Count-based assessment of cardiac output also correlated well with cineangiographic values. Results show that right and left ventricular volumes and cardiac output can be reliably measured in children with equilibrium radionuclide ventriculography.

  1. Cardiac abnormalities in liver cirrhosis.

    PubMed Central

    Lee, S S

    1989-01-01

    Cirrhosis is associated with several circulatory abnormalities. A hyperkinetic circulation characterized by increased cardiac output and decreased arterial pressure and peripheral resistance is typical. Despite this hyperkinetic circulation, some patients with alcoholic cirrhosis have subclinical cardiomyopathy with evidence of abnormal ventricular function unmasked by physiologic or pharmacologic stress. Florid congestive alcoholic cardiomyopathy develops in a small percentage, but the concurrent presence of cirrhosis seems to retard the occurrence of overt heart failure. Even nonalcoholic cirrhosis may be associated with latent cardiomyopathy, although overt heart failure is not observed. Tense ascites is associated with some cardiac compromise, and removing or mobilizing ascitic fluid by paracentesis or peritoneovenous shunting results in short-term increases in cardiac output. Cirrhosis also appears to be associated with a decreased risk of major coronary atherosclerosis and an increased risk of bacterial endocarditis. Small hemodynamically insignificant pericardial effusions may be seen in ascitic patients. The release of atrial natriuretic peptide appears to be unimpaired in cirrhosis, although the kidney may be hyporesponsive to its natriuretic effects. PMID:2690463

  2. Development lifts Egyptian output

    SciTech Connect

    Not Available

    1981-08-01

    Oil revenue is now the largest source of foreign exchange for the Arab Republic of Egypt, and, as such, is of vital importance to the country's plans for industrial and social development. Last year oil exports earned Egypt $2.9 billion, playing a key role in keeping the nation's economy in the black. Oil production in 1980 averaged 585,000 bpd, up from 510,000 bpd in 1979. This year oil output should average 650,000 bpd. While output is increasing, it does not appear to be doing so at a sufficient rate to meet the 1984 government target of 1 million bpd. However, the oil industry view in Egypt is that this target is achievable, though not until the mid to late 1980s. Development work scheduled for completion by 1984 only seems set to lift output to between 750,000 and 800,000 bpd. At the same time, if expansions plans for gas production are taken into account, then total hydrocarbon output measured in oil equivalents will not be too far short of the 1-million-bpd figure.

  3. Diodes stabilize LED output

    NASA Technical Reports Server (NTRS)

    Deters, R. A.

    1977-01-01

    Small-signal diodes are placed in series with light-emitting diodes (LED's) to stabilize LED output against temperature fluctuations. Simple inexpensive method compensates for thermal fluctuations over a broad temperature range. Requiring few components, technique is particularly useful where circuit-board space is limited.

  4. Thymosin-?4 prevents cardiac rupture and improves cardiac function in mice with myocardial infarction

    PubMed Central

    Peng, Hongmei; Xu, Jiang; Yang, Xiao-Ping; Dai, Xiangguo; Peterson, Edward L.; Carretero, Oscar A.

    2014-01-01

    Thymosin-?4 (T?4) promotes cell survival, angiogenesis, and tissue regeneration and reduces inflammation. Cardiac rupture after myocardial infarction (MI) is mainly the consequence of excessive regional inflammation, whereas cardiac dysfunction after MI results from a massive cardiomyocyte loss and cardiac fibrosis. It is possible that T?4 reduces the incidence of cardiac rupture post-MI via anti-inflammatory actions and that it decreases adverse cardiac remodeling and improves cardiac function by promoting cardiac cell survival and cardiac repair. C57BL/6 mice were subjected to MI and treated with either vehicle or T?4 (1.6 mgkg?1day?1 ip via osmotic minipump) for 7 days or 5 wk. Mice were assessed for 1) cardiac remodeling and function by echocardiography; 2) inflammatory cell infiltration, capillary density, myocyte apoptosis, and interstitial collagen fraction histopathologically; 3) gelatinolytic activity by in situ zymography; and 4) expression of ICAM-1 and p53 by immunoblot analysis. T?4 reduced cardiac rupture that was associated with a decrease in the numbers of infiltrating inflammatory cells and apoptotic myocytes, a decrease in gelatinolytic activity and ICAM-1 and p53 expression, and an increase in the numbers of CD31-positive cells. Five-week treatment with T?4 ameliorated left ventricular dilation, improved cardiac function, markedly reduced interstitial collagen fraction, and increased capillary density. In a murine model of acute MI, T?4 not only decreased mortality rate as a result of cardiac rupture but also significantly improved cardiac function after MI. Thus, the use of T?4 could be explored as an alternative therapy in preventing cardiac rupture and restoring cardiac function in patients with MI. PMID:25015963

  5. An updated model for nitrate uptake modelling in plants. II. Assessment of active root involvement in nitrate uptake based on integrated root system age: measured versus modelled outputs

    PubMed Central

    Malagoli, Philippe; Le Deunff, Erwan

    2014-01-01

    Background and Aims An updated version of a mechanistic structuralfunctional model was developed to predict nitrogen (N) uptake throughout the growth cycle by a crop of winter oilseed rape, Brassica napus, grown under field conditions. Methods The functional component of the model derives from a revisited conceptual framework that combines the thermodynamic FlowForce interpretation of nitrate uptake isotherms and environmental and in planta effects on nitrate influx. Estimation of the root biomass (structural component) is based upon a combination of root mapping along the soil depth profile in the field and a relationship between the specific root length and external nitrate concentration. The root biomass contributing actively to N uptake was determined by introduction of an integrated root system age that allows assignment of a root absorption capacity at a specific age of the root. Key Results Simulations were well matched to measured data of N taken up under field conditions for three levels of N fertilization. The model outputs indicated that the two topsoil layers (030 and 3060 cm) contained 7588 % of the total root length and biomass, and accounted for 9095 % of N taken up at harvest. Conclusions This conceptual framework provides a model of nitrate uptake that is able to respond to external nitrate fluctuations at both functional and structural levels. PMID:24709791

  6. An updated model for nitrate uptake modelling in plants. II. Assessment of active root involvement in nitrate uptake based on integrated root system age: measured versus modelled outputs.

    PubMed

    Malagoli, Philippe; Le Deunff, Erwan

    2014-05-01

    Background and Aims An updated version of a mechanistic structural-functional model was developed to predict nitrogen (N) uptake throughout the growth cycle by a crop of winter oilseed rape, Brassica napus, grown under field conditions. Methods The functional component of the model derives from a revisited conceptual framework that combines the thermodynamic Flow-Force interpretation of nitrate uptake isotherms and environmental and in planta effects on nitrate influx. Estimation of the root biomass (structural component) is based upon a combination of root mapping along the soil depth profile in the field and a relationship between the specific root length and external nitrate concentration. The root biomass contributing actively to N uptake was determined by introduction of an integrated root system age that allows assignment of a root absorption capacity at a specific age of the root. Key Results Simulations were well matched to measured data of N taken up under field conditions for three levels of N fertilization. The model outputs indicated that the two topsoil layers (0-30 and 30-60 cm) contained 75-88 % of the total root length and biomass, and accounted for 90-95 % of N taken up at harvest. Conclusions This conceptual framework provides a model of nitrate uptake that is able to respond to external nitrate fluctuations at both functional and structural levels. PMID:24709791

  7. Climate Model Output Rewriter

    Energy Science and Technology Software Center (ESTSC)

    2004-06-21

    CMOR comprises a set of FORTRAN 90 dunctions that can be used to produce CF-compliant netCDF files. The structure of the files created by CMOR and the metadata they contain fulfill the requirements of many of the climate community’s standard model experiments (which are referred to here as "MIPS", which stands for "model intercomparison project", including, for example, AMIP, CMIP, CFMIP, PMIP, APE, and IPCC scenario runs), CMOR was not designed to serve as anmore » all-purpose wfiter of CF-compliant netCDF files, but simply to reduce the effort required to prepare and manage MIP data. Although MIPs encourage systematic analysis of results across models, this is only easy to do if the model output is written in a common format with files structured similarly and with sufficient metadata uniformly stored according to a common standard. Individual modeling groups store their data in different ways. but if a group can read its own data with FORTRAN, then it should easily be able to transform the data, using CMOR, into the common format required by the MIPs, The adoption of CMOR as a standard code for exchanging climate data will facilitate participation in MIPs because after learning how to satisfy the output requirements of one MIP, it will be easy to prepare output for the other MIPs.« less

  8. Assessment of dedicated low-dose cardiac micro-CT reconstruction algorithms using the left ventricular volume of small rodents as a performance measure

    SciTech Connect

    Maier, Joscha; Sawall, Stefan; Kachelrieß, Marc

    2014-05-15

    Purpose: Phase-correlated microcomputed tomography (micro-CT) imaging plays an important role in the assessment of mouse models of cardiovascular diseases and the determination of functional parameters as the left ventricular volume. As the current gold standard, the phase-correlated Feldkamp reconstruction (PCF), shows poor performance in case of low dose scans, more sophisticated reconstruction algorithms have been proposed to enable low-dose imaging. In this study, the authors focus on the McKinnon-Bates (MKB) algorithm, the low dose phase-correlated (LDPC) reconstruction, and the high-dimensional total variation minimization reconstruction (HDTV) and investigate their potential to accurately determine the left ventricular volume at different dose levels from 50 to 500 mGy. The results were verified in phantom studies of a five-dimensional (5D) mathematical mouse phantom. Methods: Micro-CT data of eight mice, each administered with an x-ray dose of 500 mGy, were acquired, retrospectively gated for cardiac and respiratory motion and reconstructed using PCF, MKB, LDPC, and HDTV. Dose levels down to 50 mGy were simulated by using only a fraction of the projections. Contrast-to-noise ratio (CNR) was evaluated as a measure of image quality. Left ventricular volume was determined using different segmentation algorithms (Otsu, level sets, region growing). Forward projections of the 5D mouse phantom were performed to simulate a micro-CT scan. The simulated data were processed the same way as the real mouse data sets. Results: Compared to the conventional PCF reconstruction, the MKB, LDPC, and HDTV algorithm yield images of increased quality in terms of CNR. While the MKB reconstruction only provides small improvements, a significant increase of the CNR is observed in LDPC and HDTV reconstructions. The phantom studies demonstrate that left ventricular volumes can be determined accurately at 500 mGy. For lower dose levels which were simulated for real mouse data sets, the HDTV algorithm shows the best performance. At 50 mGy, the deviation from the reference obtained at 500 mGy were less than 4%. Also the LDPC algorithm provides reasonable results with deviation less than 10% at 50 mGy while PCF and MKB reconstruction show larger deviations even at higher dose levels. Conclusions: LDPC and HDTV increase CNR and allow for quantitative evaluations even at dose levels as low as 50 mGy. The left ventricular volumes exemplarily illustrate that cardiac parameters can be accurately estimated at lowest dose levels if sophisticated algorithms are used. This allows to reduce dose by a factor of 10 compared to today's gold standard and opens new options for longitudinal studies of the heart.

  9. Left atrial volume assessment in atrial fibrillation using multimodality imaging: a comparison of echocardiography, invasive three-dimensional CARTO and cardiac magnetic resonance imaging.

    PubMed

    Rabbat, Mark G; Wilber, David; Thomas, Kevin; Malick, Owais; Bashir, Atif; Agrawal, Anoop; Biswas, Santanu; Sanagala, Thriveni; Syed, Mushabbar A

    2015-06-01

    Left atrial size in atrial fibrillation is a strong predictor of successful ablation and cardiovascular events. Cardiac magnetic resonance multislice method (CMR-MSM) is the current gold standard for left atrial volume (LAV) assessment but is time consuming. We investigated whether LAV with more rapid area-length method by echocardiography (Echo-AL) or cardiac magnetic resonance (CMR-AL) and invasive measurement by 3D-CARTO mapping during ablation correlate with the CMR-MSM. We studied 250 consecutive patients prior to atrial fibrillation ablation. CMR images were acquired on 3T scanner to measure LAV by MSM and biplane area-length method. Standard echocardiography views were used to calculate LAV by biplane area-length method. LAV during ablation was measured by 3D-CARTO mapping. LAV was compared using intra-class correlation (ICC), Pearson's correlation and Bland-Altman plots. CMR-MSM was used as the reference standard. Mean LAV using CMR-MSM was 112.7 ± 36.7 ml. CMR-AL method overestimated LAV by 13.3 ± 21.8 ml (11.2%, p < 0.005) whereas 3D-CARTO and Echo-AL underestimated LAV by 8.3 ± 22.6 and 24.0 ± 27.6 ml respectively (8.7% and 20.0% respectively, p < 0.005). There was no significant difference between paroxysmal and persistent atrial fibrillation. CMR-AL and 3D-CARTO correlated and agreed well with CMR-MSM (r = 0.87 and 0.74, ICC = 0.80 and 0.77 respectively). However, Echo-AL had poor correlation and agreement with CMR-MSM (r = 0.66 and ICC = 0.48). Bland-Altman plots confirmed these findings. CMR-AL method may be used as an alternative to CMR-MSM, as it is non-invasive, rapid, and correlates well with CMR-MSM. LAV by different modalities should not be used interchangeably. PMID:25761533

  10. Role of breathing in cardiac performance: experimental and mathematical models

    NASA Astrophysics Data System (ADS)

    Tran, Binh Q.; Hoffman, Eric A.

    1999-05-01

    Due to the close proximity of the heart and lungs within a closed chest environment, we expect breathing to affect various cardiac performance parameters and hence cardiac output. We present an integrative approach to study heart-lung interactions, combining a mathematical formulation of the circulation system with imaging techniques using echo-planar magnetic resonance imaging (EPI) and dynamic x-ray CT (EBCT). We hypothesize that appropriate synchronization of mechanical ventilation to cardiac-cycle specific events can improve cardiac function, i.e. stroke volume (SV) and cardiac output (CO). Computational and experimental results support the notion that heart-lung interaction, leading to altered cardiac output associated with inspiration/expiration, is not directly associated with lung inflation/deflation and thus is felt to be more influenced by pleural pressure changes. The mathematical model of the circulation demonstrates the importance of cardiac-cycle specific timing of ventilation on cardiac function and matches with experimentally observed relationships found in animal models studied via EBCT and human studies using EPI. Results show that positive pressure mechanical ventilation timed to systolic events may increase SV and CO by up to 30%, mainly by increased filling of the ventricles during diastole. Similarly, negative pressure (spontaneous) respiration has its greatest effect on ventricular diastolic filling. Cardiac-gated mechanical ventilation may provide sufficient cardiac augmentation to warrant further investigation as a minimally-invasive technique for temporary cardiac assist. Through computational modeling and advanced imaging protocols, we were able to uniquely study heart-lung interactions within the intact milieu of the never-invaded thorax.

  11. Cardiac regeneration therapy: connections to cardiac physiology.

    PubMed

    Takehara, Naofumi; Matsubara, Hiroaki

    2011-12-01

    Without heart transplantation, a large number of patients with failing hearts worldwide face poor outcomes. By means of cardiomyocyte regeneration, cardiac regeneration therapy is emerging with great promise as a means for restoring loss of cardiac function. However, the limited success of clinical trials using bone marrow-derived cells and myoblasts with heterogeneous constituents, transplanted at a wide range of cell doses, has led to disagreement on the efficacy of cell therapy. It is therefore essential to reevaluate the evidence for the efficacy of cell-based cardiac regeneration therapy, focusing on targets, materials, and methodologies. Meanwhile, the revolutionary innovation of cardiac regeneration therapy is sorely needed to help the millions of people who suffer heart failure from acquired loss of cardiomyocytes. Cardiac regeneration has been used only in limited species or as a developing process in the rodent heart; now, the possibility of cardiomyocyte turnover in the human heart is being revisited. In the pursuit of this concept, the use of cardiac stem/progenitor stem cells in the cardiac niche must be focused to usher in a second era of cardiac regeneration therapy for the severely injured heart. In addition, tissue engineering and cellular reprogramming will advance the next era of treatment that will enable current cell-based therapy to progress to "real" cardiac regeneration therapy. Although many barriers remain, the prevention of refractory heart failure through cardiac regeneration is now becoming a realistic possibility. PMID:21963835

  12. [Cardiac rehabilitation after myocardial infarction].

    PubMed

    Ghannem, M; Ghannem, L; Ghannem, L

    2015-12-01

    Although the proofs of the benefits of cardiac rehabilitation accumulate, many patients are not sent to rehabilitation units, especially younger and very elderly patients. As the length of stay in acute care units decreases, rehabilitation offers more time to fully assess the patients' conditions and needs. Meta-analyses of randomised trials suggest that mortality can be improved by as much as 20-30%. In addition, rehabilitation helps managing risk factors, including hyperlipidemia, diabetes, smoking and sedentary behaviours. Physical training also helps improving exercise capacity. Because of all of these effects, cardiac rehabilitation for post-myocardial infarction patients has been given a class IA recommendation in current guidelines. PMID:26548984

  13. An electricity-focused economic input-output model: Life-cycle assessment and policy implications of future electricity generation scenarios

    NASA Astrophysics Data System (ADS)

    Marriott, Joe

    The electricity industry is extremely important to both our economy and our environment. We would like to be able to examine the economic, environmental and policy implications of both future electricity scenarios which include advanced generation technologies such as gasified coal, and of the products and processes which will use them, along with the interaction of this industry with the rest of the economy. This work builds upon an existing economic input-output framework, by adding detail about the electricity industry, specifically by differentiating among the various functions of the sector, and the different means of generating power. The mix of electricity consumed at any stage in the life-cycle of a product, process or industrial sector has a significant effect on the associated inventory of emissions. Fossil fuel or nuclear generators, large-scale hydroelectric, and renewable options such as geothermal, wind and solar each have a unique set of issues---both in the production of electricity at the plant and throughout the supply chain. Decision makers need better information regarding the environmental and economic impact of the electricity industry, including full supply chain details---the interaction of the electricity industry with the other 500 sectors of the economy. A systematic method for creating updated state level and sector generation mixes is developed. The results show that most sector mixes are very close to the U.S. average due to geographic dispersion of industries, but that some sectors are different, and they tend to be important raw material extraction or primary manufacturing industries. We then build a flexible framework for creating new sectors, supply chains and emission factors for the generation, transmission and distribution portions of the electricity industry. We look at scenarios of the present and future, for electricity and for particular products, and develop results which show environmental impacts split up by generation type, and with full supply chain detail. For analyses of the current electricity system and products, economic and environmental results match well with external verification sources, but for analyses of the future, there is significant uncertainty.

  14. Quantitative Assessment of Cardiac Function in Fetuses of Women with Maternal Gestational Thyroid Dysfunction Using VVI Echocardiography

    PubMed Central

    Liu, Meixin; Yu, Jing; Fu, Xiuxiu; Wan, Wei

    2015-01-01

    Background The study aimed to investigate the clinical value of velocity vector imaging (VVI) in assessing heart function in fetuses of pregnant women with thyroid dysfunction. The inter-observer and intra-observer variability was assessed for all VVI parameters observed. Material/Methods The participants were enrolled from singleton pregnant women with gestational ages ranging 24+0 to 40+1 weeks who visited the Department of Obstetrics and Gynecology at the Affiliated Hospital of Qingdao University, China, for prenatal care from July 2011 to February 2014. Digital 2-dimensional (2D) dynamic 4-chamber images of the heart were collected. A total of qualified 226 images from 125 fetuses of pregnant women with normal thyroid (control group), 64 fetuses of pregnant women with hypothyroidism (hypothyroidism group), and 37 fetuses of pregnant women with hyperthyroidism (hyperthyroidism group) were interrogated offline using VVI software. The echocardiographic parameters including the myocardium peak systolic velocity (Vs), peak diastolic velocity (Vd), peak systolic strain (S), peak systolic strain rate (SRs), peak diastolic strain rate (SRd) of RV and LV, were obtained from the velocity curves of 2D myocardial motion. The heart rate was measured using a virtual M-mode algorithm built into the software. Results The study found that the longitudinal Vs and Vd of both ventricles in the control group gradually decreased from basal segments to apical segments and significantly increased over the gestation. S, SRs, and SRd of both ventricles remained stable after middle gestation. Compared with the control group, the hypothyroidism and hyperthyroidism groups exhibited significantly reduced S, SRs, and SRd, even for fetuses at 24-weeks gestation. There were no significant differences in global Vs and global Vd between the control group and the hyperthyroidism or hypothyroidism groups. Conclusions The thyroid dysfunction of pregnant women may damage fetal heart function, and VVI could be a sensitive technique to measure the variation of fetal heart function. PMID:26427319

  15. Assessment of a Multiple Model Based Parametric Method for Output-Only Vibration-Based Damage Detection for a Population of Like Structures

    NASA Astrophysics Data System (ADS)

    Vamvoudakis-Stefanou, Kyriakos J.; Sakellariou, John S.; Fassois, Spilios D.

    2015-07-01

    This study focuses on the problem of vibration-based damage detection for a population of like structures. Although nominally identical, like structures exhibit variability in their characteristics due to variability in the materials and manufacturing. This inevitably leads to variability in the dynamics, which may be so significant as to mask deviations due to damage. Damage detection via conventional vibration-based methods, using a common threshold in the decision making mechanism thus becomes highly challenging. The study presents a detailed assessment of a recently introduced Multiple Model (MM) based AutoRegressive (AR) model parameter method aiming at addressing this problem. The assessment is based on high numbers of experimental test/inspection cases using composite beams damaged via impact, as well as comparisons with the corresponding conventional (single model based) method. The results confirm significant improvement over the method's conventional counterpart. A sensitivity analysis additionally indicates that the method is relatively insensitive to the model order, but sensitive to the specific beams selected as baseline (training) ones; in fact their selection may lead to excellent results.

  16. Cardiac AAV9 Gene Delivery Strategies in Adult Canines: Assessment by Long-term Serial SPECT Imaging of Sodium Iodide Symporter Expression.

    PubMed

    Moulay, Gilles; Ohtani, Tomohito; Ogut, Ozgur; Guenzel, Adam; Behfar, Atta; Zakeri, Rosita; Haines, Philip; Storlie, Jimmy; Bowen, Lorna; Pham, Linh; Kaye, David; Sandhu, Gurpreet; O'Connor, Michael; Russell, Stephen; Redfield, Margaret

    2015-07-01

    Heart failure is a leading cause of morbidity and mortality, and cardiac gene delivery has the potential to provide novel therapeutic approaches. Adeno-associated virus serotype 9 (AAV9) transduces the rodent heart efficiently, but cardiotropism, immune tolerance, and optimal delivery strategies in large animals are unclear. In this study, an AAV9 vector encoding canine sodium iodide symporter (NIS) was administered to adult immunocompetent dogs via epicardial injection, coronary infusion without and with cardiac recirculation, or endocardial injection via a novel catheter with curved needle and both end- and side-holes. As NIS mediates cellular uptake of clinical radioisotopes, expression was tracked by single-photon emission computerized tomography (SPECT) imaging in addition to Western blot and immunohistochemistry. Direct epicardial or endocardial injection resulted in strong cardiac expression, whereas expression after intracoronary infusion or cardiac recirculation was undetectable. A threshold myocardial injection dose that provides robust nonimmunogenic expression was identified. The extent of transmural myocardial expression was greater with the novel catheter versus straight end-hole needle delivery. Furthermore, the authors demonstrate that cardiac NIS reporter gene expression and duration can be quantified using serial noninvasive SPECT imaging up to 1 year after vector administration. These data are relevant to efforts to develop cardiac gene delivery as heart failure therapy. PMID:25915925

  17. Cardiac output and cardiac contractility by impedance cardiography during exercise of runners

    NASA Technical Reports Server (NTRS)

    Kubicek, W. G.; Tracy, R. A.

    1994-01-01

    Most of the solid state electronic engineering of the system now generally known as the Minnesota Impedance Cardiograph was performed with the support of a five-year contract, NAS9-4500, with the NASA Lyndon B. Johnson Space Center, Houston, Texas. This contract ran from 1965 to 1970. In addition to the engineering design and development of the hardware, the contract called for testing on both animals and human subjects. This project also provided funds to construct twenty impedance cardiographs and place them in selected research and clinical facilities for further evaluation. This, then, led to the First Symposium on Impedance Cardiography, held at the NASA Lyndon B. Johnson Space Center, Houston, Texas, 2-4 June 1969. Twenty-four excellent papers were presented.

  18. Cardiac Mass and Function Decrease in Bronchiolitis Obliterans Syndrome after Lung Transplantation: Relationship to Physical Activity?

    PubMed Central

    Hinrichs, Jan B.; Renne, Julius; Schoenfeld, Christian; Gutberlet, Marcel; Haverich, Axel; Warnecke, Gregor; Welte, Tobias; Wacker, Frank

    2014-01-01

    Rationale There is a need to expand knowledge on cardio-pulmonary pathophysiology of bronchiolitis obliterans syndrome (BOS) following lung transplantation (LTx). Objectives The purpose of this study was to assess MRI-derived biventricular cardiac mass and function parameters as well as flow hemodynamics in patients with and without BOS after LTx. Methods Using 1.5T cardiac MRI, measurements of myocardial structure and function as well as measurements of flow in the main pulmonary artery and ascending aorta were performed in 56 lung transplant patients. The patients were dichotomized into two gender matched groups of comparable age range: one with BOS (BOS stages 13) and one without BOS (BOS 0/0p). Measurements and Main Results Significantly lower biventricular cardiac mass, right and left ventricular end-diastolic volume, biventricular stroke volume, flow hemodynamics and significant higher heart rate but preserved cardiac output were observed in patients with BOS 13 compared to the BOS 0/0p group (p<0.05). In a stepwise logistic regression analysis global cardiac mass (p?=?0.046) and days after LTx (p?=?0.0001) remained independent parameters to predict BOS. In a second model an indicator for the physical fitness level - walking number of stairs - was added to the logistic regression model. In this second model, time after LTx (p?=?0.005) and physical fitness (p?=?0.01) remained independent predictors for BOS. Conclusion The observed changes in biventricular cardiac mass and function as well as changes in hemodynamic flow parameters in the pulmonary trunk and ascending aorta are likely attributed to the physical fitness level of patients after lung transplantation, which in turn is strongly related to lung function. PMID:25479016

  19. Effects of systolic overload and swim training on cardiac mechanics and biochemistry in rats.

    PubMed

    Buttrick, P M; Malhotra, A; Scheuer, J

    1988-04-01

    We have previously shown that swim conditioning corrects the depressed mechanical function and myosin adenosinetriphosphatase (ATPase) activities associated with renovascular hypertension (HTN) in the rat. The present study was designed to assess the effects of swim conditioning on another form of systolic overload, subdiaphragmatic suprarenal aortic stenosis. Cardiac mechanics in an isolated working heart apparatus and myosin enzymology were studied in four groups of rats: controls (C), animals with chronic systolic overload secondary to aortic constriction (St), swim-conditioning animals (Sw), and animals exposed to a combined load (St-Sw). Heart weight was increased by 23% in St, 27% in Sw, and 36% in St-Sw. In contrast to HTN, cardiac pump and muscle function were not depressed in St. Sw was associated with improved cardiac output, stroke work, and velocity of circumferential fiber shortening. St-Sw showed improved mechanical cardiac performance relative to both C and St. The percent of ventricular myosin of the V1 type and Ca2+-activated myosin ATPase activity relative to C was unchanged in Sw but was depressed in St and St-Sw. These data demonstrate that the salutory mechanical effects of Sw can be superimposed on the systolic overload of St. However, the dissociation between mechanics and myosin enzymology suggests that factors in excitation-contraction coupling other than myosin isoenzyme shifts are responsible for this finding. PMID:2967813

  20. Diabetes and cardiac autonomic neuropathy: Clinical manifestations, cardiovascular consequences, diagnosis and treatment

    PubMed Central

    Balcıoğlu, Akif Serhat; Müderrisoğlu, Haldun

    2015-01-01

    Cardiac autonomic neuropathy (CAN) is a frequent chronic complication of diabetes mellitus with potentially life-threatening outcomes. CAN is caused by the impairment of the autonomic nerve fibers regulating heart rate, cardiac output, myocardial contractility, cardiac electrophysiology and blood vessel constriction and dilatation. It causes a wide range of cardiac disorders, including resting tachycardia, arrhythmias, intraoperative cardiovascular instability, asymptomatic myocardial ischemia and infarction and increased rate of mortality after myocardial infarction. Etiological factors associated with autonomic neuropathy include insufficient glycemic control, a longer period since the onset of diabetes, increased age, female sex and greater body mass index. The most commonly used methods for the diagnosis of CAN are based upon the assessment of heart rate variability (the physiological variation in the time interval between heartbeats), as it is one of the first findings in both clinically asymptomatic and symptomatic patients. Clinical symptoms associated with CAN generally occur late in the disease process and include early fatigue and exhaustion during exercise, orthostatic hypotension, dizziness, presyncope and syncope. Treatment is based on early diagnosis, life style changes, optimization of glycemic control and management of cardiovascular risk factors. Medical therapies, including aldose reductase inhibitors, angiotensin-converting enzyme inhibitors, prostoglandin analogs and alpha-lipoic acid, have been found to be effective in randomized controlled trials. The following article includes the epidemiology, clinical findings and cardiovascular consequences, diagnosis, and approaches to prevention and treatment of CAN. PMID:25685280

  1. Taurine depresses cardiac contractility and enhances systemic heart glucose utilization in the cuttlefish, Sepia officinalis.

    PubMed

    MacCormack, Tyson J; Callaghan, N I; Sykes, A V; Driedzic, W R

    2016-02-01

    Taurine is the most abundant amino acid in the blood of the cuttlefish, Sepia officinalis, where levels can exceed 200 mmol L(-1). In mammals, intracellular taurine modulates cardiac Ca(2+) handling and carbohydrate metabolism at much lower concentrations but it is not clear if it exerts similar actions in cephalopods. Blood Ca(2+) levels are high in cephalopods and we hypothesized that taurine would depress cardiac Ca(2+) flux and modulate contractility in systemic and branchial hearts of cuttlefish. Heart performance was assessed with an in situ perfused systemic heart preparation and contractility was evaluated using isometrically contracting systemic and branchial heart muscle rings. Stroke volume, cardiac output, and Ca(2+) sensitivity were significantly lower in systemic hearts perfused with supplemental taurine (100 mmol L(-1)) than in controls. In muscle ring preparations, taurine impaired relaxation at high contraction frequencies, an effect abolished by supra-physiological Ca(2+) levels. Taurine did not affect oxygen consumption in non-contracting systemic heart muscle, but extracellular glucose utilization was twice that of control preparations. Collectively, our results suggest that extracellular taurine depresses cardiac Ca(2+) flux and potentiates glucose utilization in cuttlefish. Variations in taurine levels may represent an important mechanism for regulating cardiovascular function and metabolism in cephalopods. PMID:26644087

  2. Two-scale evaluation of remediation technologies for a contaminated site by applying economic input-output life cycle assessment: risk-cost, risk-energy consumption and risk-CO2 emission.

    PubMed

    Inoue, Yasushi; Katayama, Arata

    2011-09-15

    A two-scale evaluation concept of remediation technologies for a contaminated site was expanded by introducing life cycle costing (LCC) and economic input-output life cycle assessment (EIO-LCA). The expanded evaluation index, the rescue number for soil (RN(SOIL)) with LCC and EIO-LCA, comprises two scales, such as risk-cost, risk-energy consumption or risk-CO(2) emission of a remediation. The effectiveness of RN(SOIL) with LCC and EIO-LCA was examined in a typical contamination and remediation scenario in which dieldrin contaminated an agricultural field. Remediation was simulated using four technologies: disposal, high temperature thermal desorption, biopile and landfarming. Energy consumption and CO(2) emission were determined from a life cycle inventory analysis using monetary-based intensity based on an input-output table. The values of RN(SOIL) based on risk-cost, risk-energy consumption and risk-CO(2) emission were calculated, and then rankings of the candidates were compiled according to RN(SOIL) values. A comparison between three rankings showed the different ranking orders. The existence of differences in ranking order indicates that the scales would not have reciprocal compatibility for two-scale evaluation and that each scale should be used independently. The RN(SOIL) with LCA will be helpful in selecting a technology, provided an appropriate scale is determined. PMID:21741766

  3. Protocol for the China PEACE (Patient-centered Evaluative Assessment of Cardiac Events) retrospective study of coronary catheterisation and percutaneous coronary intervention

    PubMed Central

    Li, Jing; Dharmarajan, Kumar; Li, Xi; Lin, Zhenqiu; Normand, Sharon-Lise T; Krumholz, Harlan M; Jiang, Lixin

    2014-01-01

    Introduction During the past decade, the volume of percutaneous coronary intervention (PCI) in China has risen by more than 20-fold. Yet little is known about patterns of care and outcomes across hospitals, regions and time during this period of rising cardiovascular disease and dynamic change in the Chinese healthcare system. Methods and analysis Using the China PEACE (Patient-centered Evaluative Assessment of Cardiac Events) research network, the Retrospective Study of Coronary Catheterisation and Percutaneous Coronary Intervention (China PEACE-Retrospective CathPCI Study) will examine a nationally representative sample of 11 900 patients who underwent coronary catheterisation or PCI at 55 Chinese hospitals during 2001, 2006 and 2011. We selected patients and study sites using a two-stage cluster sampling design with simple random sampling stratified within economical-geographical strata. A central coordinating centre will monitor data quality at the stages of case ascertainment, medical record abstraction and data management. We will examine patient characteristics, diagnostic testing patterns, procedural treatments and in-hospital outcomes, including death, complications of treatment and costs of hospitalisation. We will additionally characterise variation in treatments and outcomes by patient characteristics, hospital, region and study year. Ethics and dissemination The China PEACE collaboration is designed to translate research into improved care for patients. The study protocol was approved by the central ethics committee at the China National Center for Cardiovascular Diseases (NCCD) and collaborating hospitals. Findings will be shared with participating hospitals, policymakers and the academic community to promote quality monitoring, quality improvement and the efficient allocation and use of coronary catheterisation and PCI in China. Registration details http://www.clinicaltrials.gov (NCT01624896). PMID:24607563

  4. Cerebral Oximetry as a Real-Time Monitoring Tool to Assess Quality of In-Hospital Cardiopulmonary Resuscitation and Post Cardiac Arrest Care

    PubMed Central

    Ibrahim, Akram W; Trammell, Antoine R; Austin, Harland; Barbour, Kenya; Onuorah, Emeka; House, Dorothy; Miller, Heather L; Tutt, Chandila; Combs, Deborah; Phillips, Roger; Dickert, Neal W; Zafari, A Maziar

    2015-01-01

    Background Regional cerebral oxygen saturation (rSO2) as assessed by near infrared frontal cerebral spectroscopy decreases in circulatory arrest and increases with high-quality cardiopulmonary resuscitation. We hypothesized that higher rSO2 during cardiopulmonary resuscitation and after return of spontaneous circulation (ROSC) would predict survival to discharge and neurological recovery. Methods and Results This prospective case series included patients experiencing in-hospital cardiac arrest. Cerebral oximetry was recorded continuously from initiation of resuscitation until ROSC and up to 48hours post-arrest. Relationships between oximetry data during these time periods and outcomes of resuscitation survival and survival to discharge were analyzed. The cohort included 27 patients. Nineteen (70.3%) achieved ROSC, and 8 (29.6%) survived to discharge. Median arrest duration was 20.8minutes (range =8 to 74). There was a significant difference in rSO2 between resuscitation survivors and resuscitation nonsurvivors at initiation of the resuscitative efforts (35% versus 17.5%, P =0.03) and during resuscitation (36% versus 15%, P =0.0008). No significant association was observed between rSO2 at ROSC or during the post-arrest period and survival to discharge. Among patients who survived to discharge, there was no association between cerebral performance category and rSO2 at ROSC, during resuscitation, or post-arrest. Conclusions Higher rSO2 levels at initiation of resuscitation and during resuscitation are associated with resuscitation survival and may reflect high-quality cardiopulmonary resuscitation. However, in this small series, rSO2 was not predictive of good neurological outcome. Larger studies are needed to determine whether this monitoring modality can be used to improve clinical outcomes. PMID:26307569

  5. Assessment of the cardiac safety of prucalopride in healthy volunteers: a randomized, double-blind, placebo- and positive-controlled thorough QT study

    PubMed Central

    Mendzelevski, Boaz; Ausma, Jannie; Chanter, Dennis O; Robinson, Patricia; Kerstens, Rene; Vandeplassche, Lieve; Camm, John

    2012-01-01

    AIMS To assess steady-state effects of therapeutic and supra-therapeutic doses of prucalopride on the QT interval using a novel design involving a parallel placebo group with nested crossover for positive control. METHODS A double-blind, double-dummy, placebo- and active-controlled study was conducted in 120 healthy male and female volunteers (NCT00903747). Volunteers were randomized to receive prucalopride 2–10 mg once daily (therapeutic and supratherapeutic doses, respectively) (group 1), placebo with 400 mg moxifloxacin on day 1 (group 2a), or placebo with moxifloxacin on day 15 (group 2b). Twelve-lead 24 h Holter ECGs recorded at various time-points were evaluated blind and centrally. RESULTS Estimated mean difference in study specific corrected QT interval (QTcSS) time-matched change from baseline between prucalopride (2 and 10 mg) and placebo was <5 ms at all time points (maximum mean difference: 3.83 ms at 3.5 h post dose on day 5 with 2 mg [90% Cl −0.33, 6.38 ms]). Upper limits of the two-sided 90% CI for QTcSS were all <10 ms. There were no outlying QTcSS values >450 ms and no subjects had an increase >60 ms following prucalopride. Moxifloxacin produced the expected significant changes in QTcSS (>5 ms, maximum of +12.7 ms at 5 h post dose) at all time-points except 1 h post dose. Prucalopride resulted in small increases in heart rate (maximum of 5.8 beats min–1), which were similar for 2 and 10 mg. Prucalopride was well tolerated after first day of treatment. CONCLUSION Prucalopride at both therapeutic and supra therapeutic doses has no clinically significant effects on cardiac repolarisation in healthy volunteers. PMID:21848574

  6. The China PEACE (Patient-centered Evaluative Assessment of Cardiac Events) Retrospective Study of Acute Myocardial Infarction: Study Design China PEACE-Retrospective AMI Study Design

    PubMed Central

    Dharmarajan, Kumar; Li, Jing; Li, Xi; Lin, Zhenqiu; Krumholz, Harlan; Jiang, Lixin

    2014-01-01

    Background Cardiovascular diseases are rising as a cause of death and disability in China. To improve outcomes for patients with these conditions, the Chinese government, academic researchers, clinicians, and more than 200 hospitals have created China Patient-centered Evaluative Assessment of Cardiac Events (China-PEACE), a national network for research and performance improvement. The first study from China PEACE, the Retrospective Study of Acute Myocardial Infarction (China PEACE-Retrospective AMI Study), is designed to promote improvements in AMI quality of care by generating knowledge about the characteristics, treatments, and outcomes of patients hospitalized with acute myocardial infarction (AMI) across a representative sample of Chinese hospitals over the last decade. Methods and Results The China PEACE-Retrospective AMI Study will examine more than 18,000 patient records from 162 hospitals identified using a 2-stage cluster sampling design within economic-geographic regions. Records were chosen from 2001, 2006, and 2011 to identify temporal trends. Data quality will be monitored by a central coordinating center and will, in particular, address case ascertainment, data abstraction, and data management. Analyses will examine patient characteristics, diagnostic testing patterns, in-hospital treatments, in-hospital outcomes, and variation in results by time and site of care. In addition to publications, data will be shared with participating hospitals and the Chinese government to develop strategies to promote quality improvement. Conclusions The China PEACE-Retrospective AMI Study is the first to leverage the China PEACE platform to better understand AMI across representative sites of care and over the last decade in China. The China PEACE collaboration between government, academicians, clinicians and hospitals is poised to translate research about trends and patterns of AMI practices and outcomes into improved care for patients. PMID:24221838

  7. Assessment of radiochromic gel dosimeter based on Turnbull Blue dye for relative output factor measurements of the Leksell Gamma Knife PerfexionTM

    NASA Astrophysics Data System (ADS)

    Kozubikova, P.; Solc, J.; Novotny, J., Jr.; Pilarova, K.; Pipek, J.; Koncekova, J.

    2015-01-01

    The aim of the study was to perform assessment of radiochromic gel dosimeter based on Turnbull blue dye formed by irradiation (TB gel dosimeter) for measurement of ROFs for 4 mm and 8 mm collimators for the Leksell Gamma Knife PerfexionTM. All measurements have been carried out using home-made spherical Perspex glass phantom of diameter 160 mm. TB gel dosimeters were scanned using homemade optical CT scanner. The results are compared with vendor recommended Monte Carlo calculated ROFs values of 0.814 and 0.900 for 4 mm and 8 mm collimators, respectively. The comparisons between the gel measurements and the treatment planning system (TPS) calculation are presented in the form of 2D isodoses for the central slices and 1D profile. Measured ROF 0.746 and 0.874 for 4 mm and 8 mm collimators respectively are in a reasonable agreement with vendor recommended values and measured relative dose distribution in a central slice and measured profiles of all shots show excellent correspondence with TPS.

  8. A methodology for fast assessments to the electrical activity of barrel fields in vivo: from population inputs to single unit outputs

    PubMed Central

    Riera, Jorge J.; Goto, Takakuni; Kawashima, Ryuta

    2014-01-01

    Here we propose a methodology to analyze volumetric electrical activity of neuronal masses in the somatosensory barrel field of Wistar rats. The key elements of the proposed methodology are a three-dimensional microelectrode array, which was customized by our group to observe extracellular recordings from an extended area of the barrel field, and a novel method for the current source density analysis. By means of this methodology, we were able to localize single barrels from their event-related responses to single whisker deflection. It was also possible to assess the spatiotemporal dynamics of neuronal aggregates in several barrels at the same time with the resolution of single neurons. We used simulations to study the robustness of our methodology to unavoidable physiological noise and electrode configuration. We compared the accuracy to reconstruct neocortical current sources with that obtained with a previous method. This constitutes a type of electrophysiological microscopy with high spatial and temporal resolution, which could change the way we analyze the activity of cortical neurons in the future. PMID:24550785

  9. Cardiac overexpression of human VEGF165 by recombinant Semliki Forest virus leads to adverse effects in pressure-induced heart failure

    PubMed Central

    Loot, A.E.; Roks, A.J.M.; Westermann, D.; Orzechowski, H-D.; Tschpe, C.; Wilschut, J.C.; Tio, R.A.; van Gilst, W.H.; Henning, R.H.

    2007-01-01

    Semliki Forest virus (SFV) is an efficient vector for cardiac gene delivery. The relatively short transgene expression induced by SFV seems appropriate for angiogenic gene therapy. We tested the effects of SFV expressing vascular endothelial growth factor (VEGF) on cardiac angiogenesis and heart failure in the mRen2 transgenic rat. Six-week-old mRen2 rats received SFV-VEGF or control virus (n=7 each) administered intracoronarily. Twelve days after transfection, cardiac capillary density and function were assessed. Capillary density in cardiac regions where SFV expression was highest had decreased by 20% in the SFV-VEGF-treated group. The decrease in capillary density was accompanied by impaired systolic function as illustrated by increased endsystolic volumes and a 34% decrease in cardiac output. We conclude that the time frame of SFV expression is sufficient to induce structural alterations, but that VEGF in mRen2 transgenic rats did not elicit the expected angiogenic effect. Rather, capillary density was decreased and subsequently cardiac function was impaired. This paradoxical finding is possibly related to the pathophysiology associated with this model and warrants caution if one is to pursue VEGF-mediated, angiogenic therapy before proceeding to a clinical setting. (Neth Heart J 2007;15:335-41.18167566) PMID:18167566

  10. Cardiac overexpression of human VEGF(165) by recombinant Semliki Forest virus leads to adverse effects in pressure-induced heart failure.

    PubMed

    Loot, A E; Roks, A J M; Westermann, D; Orzechowski, H-D; Tschpe, C; Wilschut, J C; Tio, R A; van Gilst, W H; Henning, R H

    2007-01-01

    Semliki Forest virus (SFV) is an efficient vector for cardiac gene delivery. The relatively short transgene expression induced by SFV seems appropriate for angiogenic gene therapy. We tested the effects of SFV expressing vascular endothelial growth factor (VEGF) on cardiac angiogenesis and heart failure in the mRen2 transgenic rat.Six-week-old mRen2 rats received SFV-VEGF or control virus (n=7 each) administered intracoronarily. Twelve days after transfection, cardiac capillary density and function were assessed. Capillary density in cardiac regions where SFV expression was highest had decreased by 20% in the SFV-VEGF-treated group. The decrease in capillary density was accompanied by impaired systolic function as illustrated by increased endsystolic volumes and a 34% decrease in cardiac output.We conclude that the time frame of SFV expression is sufficient to induce structural alterations, but that VEGF in mRen2 transgenic rats did not elicit the expected angiogenic effect. Rather, capillary density was decreased and subsequently cardiac function was impaired. This paradoxical finding is possibly related to the pathophysiology associated with this model and warrants caution if one is to pursue VEGF-mediated, angiogenic therapy before proceeding to a clinical setting. (Neth Heart J 2007;15:335-41.). PMID:18167566

  11. Cardiac conduction system

    MedlinePLUS Videos and Cool Tools

    ... cardiac muscle cells in the walls of the heart that send signals to the heart muscle causing it to contract. The main components ... the cardiac conduction system’s electrical activity in the heart.

  12. Influence of cirrhosis in cardiac surgery outcomes.

    PubMed

    Lopez-Delgado, Juan C; Esteve, Francisco; Javierre, Casimiro; Ventura, Josep L; Maez, Rafael; Farrero, Elisabet; Torrado, Herminia; Rodrguez-Castro, David; Carrio, Maria L

    2015-04-18

    Liver cirrhosis has evolved an important risk factor for cardiac surgery due to the higher morbidity and mortality that these patients may suffer compared with general cardiac surgery population. The presence of contributing factors for a poor outcome, such as coagulopathy, a poor nutritional status, an adaptive immune dysfunction, a degree of cirrhotic cardiomyopathy, and a degree of renal and pulmonary dysfunction, have to be taken into account for surgical evaluation when cardiac surgery is needed, together with the degree of liver disease and its primary complications. The associated pathophysiological characteristics that liver cirrhosis represents have a great influence in the development of complications during cardiac surgery and the postoperative course. Despite the population of cirrhotic patients who are referred for cardiac surgery is small and recommendations come from small series, since liver cirrhotic patients have increased their chance of survival in the last 20 years due to the advances in their medical care, which includes liver transplantation, they have been increasingly considered for cardiac surgery. Indeed, there is an expected rise of cirrhotic patients within the cardiac surgical population due to the increasing rates of non-alcoholic fatty liver disease and non-alcoholic steatohepatitis, especially in western countries. In consequence, a more specific approach is needed in the assessment of care of these patients if we want to improve their management. In this article, we review the pathophysiology and outcome prediction of cirrhotic patients who underwent cardiac surgery. PMID:25914775

  13. Influence of cirrhosis in cardiac surgery outcomes

    PubMed Central

    Lopez-Delgado, Juan C; Esteve, Francisco; Javierre, Casimiro; Ventura, Josep L; Maez, Rafael; Farrero, Elisabet; Torrado, Herminia; Rodrguez-Castro, David; Carrio, Maria L

    2015-01-01

    Liver cirrhosis has evolved an important risk factor for cardiac surgery due to the higher morbidity and mortality that these patients may suffer compared with general cardiac surgery population. The presence of contributing factors for a poor outcome, such as coagulopathy, a poor nutritional status, an adaptive immune dysfunction, a degree of cirrhotic cardiomyopathy, and a degree of renal and pulmonary dysfunction, have to be taken into account for surgical evaluation when cardiac surgery is needed, together with the degree of liver disease and its primary complications. The associated pathophysiological characteristics that liver cirrhosis represents have a great influence in the development of complications during cardiac surgery and the postoperative course. Despite the population of cirrhotic patients who are referred for cardiac surgery is small and recommendations come from small series, since liver cirrhotic patients have increased their chance of survival in the last 20 years due to the advances in their medical care, which includes liver transplantation, they have been increasingly considered for cardiac surgery. Indeed, there is an expected rise of cirrhotic patients within the cardiac surgical population due to the increasing rates of non-alcoholic fatty liver disease and non-alcoholic steatohepatitis, especially in western countries. In consequence, a more specific approach is needed in the assessment of care of these patients if we want to improve their management. In this article, we review the pathophysiology and outcome prediction of cirrhotic patients who underwent cardiac surgery. PMID:25914775

  14. Effect on the cardiac function of repeated LBNP during a 1-month head down tilt

    NASA Astrophysics Data System (ADS)

    Arbeille, Ph.; Lebouard, D.; Massabuau, M.; Pottier, J. M.; Patat, F.; Pourcelot, L.; Guell, A.

    Cardiovascular assessment by ultrasound methods was performed during two long duration (1 month) Head Down Tilt (HDT) on 6 healthy volunteers. On a first 1 month HDT session, 3 of the 6 subjects (A, B, C) had daily several lower body negative pressure tests (LBNP), whereas the 3 subjects remaining (D, E, F) rested without LBNP. On a second 1 month HDT session subjects D, E, and F had daily LBNP tests and the A, B and C subjects did not. The cardiac function was assessed by Echocardiography (B mode, TM mode). On all the "6 non LBNP" subjects the left ventricule diastolic volume (LVDV), the stroke volume (SV) and the cardiac output (CO) increase (+10%, -15%) after HDT then decrease and remain inferior (-5%, -5%) or equal to the basal value during the HDT. Immediately after the end of the HDT the heart rate (HR) increase (+10%, +30%) whereas the cardiac parameters decrease weakly (-5%, -10%) and normalize after 3 days of recovery. On the "6 LBNP" subjects the LVDV, SV and CO increase (+10%, +15%) after 1 h HDT as in the previous group then decrease but remain superior (+5%, +15%) or equal to the basal value. After the HDT session, the HR is markedly increased (+20%, +40%) the LVDV and SV decrease (-15%, -20%) whereas the CO increases or decreases depending on the amplitude of the HR variations. These parameters do not completely normalize after 3 days recovery. Repeated LBNP sessions have a significant effect on the cardiovascular function as it maintains all cardiac parameters above the basal value. The LBNP manoeuvre can be considered as an efficient countermeasure to prevent cardiac disadaptation induced by HDT position and probably microgravity.

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

    NASA Technical Reports Server (NTRS)

    Hamilton, D. R.; Sargsyan, A. E.; Garcia, K. M.; Ebert, D.; Feiveson, A. H.; Alferova, I. V.; Dulchavsky, S. A.; Matveev, V. P.; Bogomolov, V. V.; Duncan, J. M.

    2011-01-01

    BACKGROUND: The transition to microgravity eliminates the hydrostatic gradients in the vascular system. The resulting fluid redistribution commonly manifests as facial edema, engorgement of the external neck veins, nasal congestion, and headache. This experiment examined the responses to modified Valsalva and Mueller maneuvers as measured by cardiac and vascular ultrasound in a baseline microgravity steady state, and under the influence of thigh occlusion cuffs (Braslet cuffs). METHODS: Nine International Space Station crewmember subjects (Expeditions 16 - 20) were examined in 15 experiment sessions 101 46 days after launch (mean SD; 33 - 185). 27 cardiac and vascular parameters were obtained under three respiratory conditions (baseline, Valsalva, and Mueller) before and after tightening of the Braslet cuffs for a total of 162 data points per session. The quality of cardiac and vascular ultrasound examinations was assured through remote monitoring and guidance by Investigators from the NASA Telescience Center in Houston, TX, USA. RESULTS: Fourteen of the 81 measured conditions were significantly different with Braslet application and were apparently related to cardiac preload reduction or increase in the venous volume sequestered in the lower extremity. These changes represented 10 of the 27 parameters measured. In secondary analysis, 7 of the 27 parameters were found to respond differently to respiratory maneuvers depending on the presence or absence of thigh compression, with a total of 11 differences. CONCLUSIONS: Acute application of Braslet occlusion cuffs causes lower extremity fluid sequestration and exerts proportionate measurable effects on cardiac performance in microgravity. Ultrasound techniques measuring the hemodynamic effects of thigh cuffs in combination with respiratory maneuvers may serve as an effective tool in determining the volume status of a cardiac or hemodynamically compromised patient in microgravity.

  16. A rare case of primary cardiac lymphoma.

    PubMed

    Khan-Kheil, Ayisha Mehtab; Mustafa, Hanif Muhammad; Anand, Dhakshinamurthy Vijay; Banerjee, Prithwish

    2015-01-01

    A 71-year-old man presented with shortness of breath and tachycardia along with systemic symptoms of weight loss and lethargy. A pulmonary embolus was the initial suspected diagnosis but through extensive investigations a rarer cause of his symptoms was identified. This case demonstrates the importance of cardiac imaging in the assessment and non-invasive tissue characterisation of a suspected cardiac tumour; in our case, this was subsequently confirmed by careful histological/immunocytochemical evaluation of the pericardial effusion as a primary cardiac B-cell non-Hodgkin's lymphoma, thus enabling appropriate management leading to an excellent clinical outcome. PMID:26538249

  17. The effect of age on the relationship between cardiac and vascular function.

    PubMed

    Houghton, David; Jones, Thomas W; Cassidy, Sophie; Siervo, Mario; MacGowan, Guy A; Trenell, Michael I; Jakovljevic, Djordje G

    2016-01-01

    Age-related changes in cardiac and vascular function are associated with increased risk of cardiovascular mortality and morbidity. The aim of the present study was to define the effect of age on the relationship between cardiac and vascular function. Haemodynamic and gas exchange measurements were performed at rest and peak exercise in healthy individuals. Augmentation index was measured at rest. Cardiac power output, a measure of overall cardiac function, was calculated as the product of cardiac output and mean arterial blood pressure. Augmentation index was significantly higher in older than younger participants (27.710.1 vs. 2.510.1%, P<0.01). Older people demonstrated significantly higher stroke volume and mean arterial blood pressure (P<0.05), but lower heart rate (14513 vs. 17210 beats/min, P<0.01) and peak oxygen consumption (22.55.2 vs. 41.28.4ml/kg/min, P<0.01). There was a significant negative relationship between augmentation index and peak exercise cardiac power output (r=-0.73, P=0.02) and cardiac output (r=-0.69, P=0.03) in older participants. Older people maintain maximal cardiac function due to increased stroke volume. Vascular function is a strong predictor of overall cardiac function in older but in not younger people. PMID:26590322

  18. Relationship between cardiac function and resting cerebral blood flow: MRI measurements in healthy elderly subjects.

    PubMed

    Henriksen, Otto M; Jensen, Lars T; Krabbe, Katja; Larsson, Henrik B W; Rostrup, Egill

    2014-11-01

    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 = 0.008) and furthermore lower in males than in females (8.6% versus 12.5%, P = 0.003). Fractional brain flow was also inversely correlated with cerebral white matter lesion grade, although this effect was not significant when adjusted for age. Frequency analysis of heart rate variability showed a gender-related inverse association of increased low-to-high-frequency power ratio with CBF and fractional brain flow. The findings do not support a direct effect of cardiac function on CBF, but demonstrates gender-related differences in cardiac output distribution. We propose fractional brain flow as a novel index that may be a useful marker of adequate brain perfusion in the context of ageing as well as cardiovascular disease. PMID:24314236

  19. Effects of prior intensive versus conventional therapy and history of glycemia on cardiac function in type 1 diabetes in the DCCT/EDIC.

    PubMed

    Genuth, Saul M; Backlund, Jye-Yu C; Bayless, Margaret; Bluemke, David A; Cleary, Patricia A; Crandall, Jill; Lachin, John M; Lima, Joao A C; Miao, Culian; Turkbey, Evrim B

    2013-10-01

    Intensive diabetes therapy reduces the prevalence of coronary calcification and progression of atherosclerosis and the risk of cardiovascular disease (CVD) events in the Diabetes Control and Complications Trial (DCCT)/Epidemiology of Diabetes Interventions and Complications (EDIC) study. The effects of intensive therapy on measures of cardiac function and structure and their association with glycemia have not been explored in type 1 diabetes (T1DM). We assess whether intensive treatment compared with conventional treatment during the DCCT led to differences in these parameters during EDIC. After 6.5 years of intensive versus conventional therapy in the DCCT, and 15 years of additional follow-up in EDIC, left ventricular (LV) indices were measured by cardiac magnetic resonance (CMR) imaging in 1,017 of the 1,371 members of the DCCT cohort. There were no differences between the DCCT intensive versus conventional treatment in end diastolic volume (EDV), end systolic volume, stroke volume (SV), cardiac output (CO), LV mass, ejection fraction, LV mass/EDV, or aortic distensibility (AD). Mean DCCT/EDIC HbA1c over time was associated with EDV, SV, CO, LV mass, LV mass/EDV, and AD. These associations persisted after adjustment for CVD risk factors. Cardiac function and remodeling in T1DM assessed by CMR in the EDIC cohort was associated with prior glycemic exposure, but there was no effect of intensive versus conventional treatment during the DCCT on cardiac parameters. PMID:23520132

  20. Early detection of cardiac dysfunction in the type 1 diabetic heart using speckle-tracking based strain imaging.

    PubMed

    Shepherd, Danielle L; Nichols, Cody E; Croston, Tara L; McLaughlin, Sarah L; Petrone, Ashley B; Lewis, Sara E; Thapa, Dharendra; Long, Dustin M; Dick, Gregory M; Hollander, John M

    2016-01-01

    Enhanced sensitivity in echocardiographic analyses may allow for early detection of changes in cardiac function beyond the detection limits of conventional echocardiographic analyses, particularly in a small animal model. The goal of this study was to compare conventional echocardiographic measurements and speckle-tracking based strain imaging analyses in a small animal model of type 1 diabetes mellitus. Conventional analyses revealed differences in ejection fraction, fractional shortening, cardiac output, and stroke volume in diabetic animals relative to controls at 6-weeks post-diabetic onset. In contrast, when assessing short- and long-axis speckle-tracking based strain analyses, diabetic mice showed changes in average systolic radial strain, radial strain rate, radial displacement, and radial velocity, as well as decreased circumferential and longitudinal strain rate, as early as 1-week post-diabetic onset and persisting throughout the diabetic study. Further, we performed regional analyses for the LV and found that the free wall region was affected in both the short- and long-axis when assessing radial dimension parameters. These changes began 1-week post-diabetic onset and remained throughout the progression of the disease. These findings demonstrate the use of speckle-tracking based strain as an approach to elucidate cardiac dysfunction from a global perspective, identifying left ventricular cardiac regions affected during the progression of type 1 diabetes mellitus earlier than contractile changes detected by conventional echocardiographic measurements. PMID:26654913

  1. Mechanisms of cardiac pain.

    PubMed

    Foreman, Robert D; Garrett, Kennon M; Blair, Robert W

    2015-04-01

    Angina pectoris is cardiac pain that typically is manifested as referred pain to the chest and upper left arm. Atypical pain to describe localization of the perception, generally experienced more by women, is referred to the back, neck, and/or jaw. This article summarizes the neurophysiological and pharmacological mechanisms for referred cardiac pain. Spinal cardiac afferent fibers mediate typical anginal pain via pathways from the spinal cord to the thalamus and ultimately cerebral cortex. Spinal neurotransmission involves substance P, glutamate, and transient receptor potential vanilloid-1 (TRPV1) receptors; release of neurokinins such as nuclear factor kappa b (NF-kb) in the spinal cord can modulate neurotransmission. Vagal cardiac afferent fibers likely mediate atypical anginal pain and contribute to cardiac ischemia without accompanying pain via relays through the nucleus of the solitary tract and the C1-C2 spinal segments. The psychological state of an individual can modulate cardiac nociception via pathways involving the amygdala. Descending pathways originating from nucleus raphe magnus and the pons also can modulate cardiac nociception. Sensory input from other visceral organs can mimic cardiac pain due to convergence of this input with cardiac input onto spinothalamic tract neurons. Reduction of converging nociceptive input from the gallbladder and gastrointestinal tract can diminish cardiac pain. Much work remains to be performed to discern the interactions among complex neural pathways that ultimately produce or do not produce the sensations associated with cardiac pain. PMID:25880519

  2. European Association of Cardiovascular Imaging/Cardiovascular Imaging Department of the Brazilian Society of Cardiology recommendations for the use of cardiac imaging to assess and follow patients after heart transplantation.

    PubMed

    Badano, Luigi P; Miglioranza, Marcelo H; Edvardsen, Thor; Colafranceschi, Alexandre Siciliano; Muraru, Denisa; Bacal, Fernando; Nieman, Koen; Zoppellaro, Giacomo; Marcondes Braga, Fabiana G; Binder, Thomas; Habib, Gilbert; Lancellotti, Patrizio

    2015-09-01

    The cohort of long-term survivors of heart transplant is expanding, and the assessment of these patients requires specific knowledge of the surgical techniques employed to implant the donor heart, the physiology of the transplanted heart, complications of invasive tests routinely performed to detect graft rejection (GR), and the specific pathologies that may affect the transplanted heart. A joint EACVI/Brazilian cardiovascular imaging writing group committee has prepared these recommendations to provide a practical guide to echocardiographers involved in the follow-up of heart transplant patients and a framework for standardized and efficient use of cardiovascular imaging after heart transplant. Since the transplanted heart is smaller than the recipient's dilated heart, the former is usually located more medially in the mediastinum and tends to be rotated clockwise. Therefore, standard views with conventional two-dimensional (2D) echocardiography are often difficult to obtain generating a large variability from patient to patient. Therefore, in echocardiography laboratories equipped with three-dimensional echocardiography (3DE) scanners and specific expertise with the technique, 3DE may be a suitable alternative to conventional 2D echocardiography to assess the size and the function of cardiac chambers. 3DE measurement of left (LV) and right ventricular (RV) size and function are more accurate and reproducible than conventional 2D calculations. However, clinicians should be aware that cardiac chamber volumes obtained with 3DE cannot be compared with those obtained with 2D echocardiography. To assess cardiac chamber morphology and function during follow-up studies, it is recommended to obtain a comprehensive echocardiographic study at 6 months from the cardiac transplantation as a baseline and make a careful quantitation of cardiac chamber size, RV systolic function, both systolic and diastolic parameters of LV function, and pulmonary artery pressure. Subsequent echocardiographic studies should be interpreted in comparison with the data obtained from the 6-month study. An echocardiographic study, which shows no change from the baseline study, has a high negative predictive value for GR. There is no single systolic or diastolic parameter that can be reliably used to diagnose GR. However, in case several parameters are abnormal, the likelihood of GR increases. When an abnormality is detected, careful revision of images of the present and baseline study (side-by-side) is highly recommended. Global longitudinal strain (GLS) is a suitable parameter to diagnose subclinical allograft dysfunction, regardless of aetiology, by comparing the changes occurring during serial evaluations. Evaluation of GLS could be used in association with endomyocardial biopsy (EMB) to characterize and monitor an acute GR or global dysfunction episode. RV size and function at baseline should be assessed using several parameters, which do not exclusively evaluate longitudinal function. At follow-up echocardiogram, all these parameters should be compared with the baseline values. 3DE may provide a more accurate and comprehensive assessment of RV size and function. Moreover, due to the unpredictable shape of the atria in transplanted patients, atrial volume should be measured using the discs' summation algorithm (biplane algorithm for the left atrium) or 3DE. Tricuspid regurgitation should be looked for and properly assessed in all echocardiographic studies. In case of significant changes in severity of tricuspid regurgitation during follow-up, a 2D/3D and colour Doppler assessment of its severity and mechanisms should be performed. Aortic and mitral valves should be evaluated according to current recommendations. Pericardial effusion should be serially evaluated regarding extent, location, and haemodynamic impact. In case of newly detected pericardial effusion, GR should be considered taking into account the overall echocardiographic assessment and patient evaluation. Dobutamine stress echocardiography might be a suitable alternative to routine coronary angiography to assess cardiac allograft vasculopathy (CAV) at centres with adequate experience with the methodology. Coronary flow reserve and/or contrast infusion to assess myocardial perfusion might be combined with stress echocardiography to improve the accuracy of the test. In addition to its role in monitoring cardiac chamber function and in diagnosis the occurrence of GR and/or CAV, in experienced centres, echocardiography might be an alternative to fluoroscopy to guide EMB, particularly in children and young women, since echocardiography avoids repeated X-ray exposure, permits visualization of soft tissues and safer performance of biopsies of different RV regions. Finally, in addition to the indications about when and how to use echocardiography, the document also addresses the role of the other cardiovascular imaging modalities during follow-up of heart transplant patients. In patients with inadequate acoustic window and contraindication to contrast agents, pharmacological SPECT is an alternative imaging modality to detect CAV in heart transplant patients. However, in centres with adequate expertise, intravascular ultrasound (IVUS) in conjunction with coronary angiography with a baseline study at 4-6 weeks and at 1 year after heart transplant should be performed to exclude donor coronary artery disease, to detect rapidly progressive CAV, and to provide prognostic information. Despite the fact that coronary angiography is the current gold-standard method for the detection of CAV, the use of IVUS should also be considered when there is a discrepancy between non-invasive imaging tests and coronary angiography concerning the presence of CAV. In experienced centres, computerized tomography coronary angiography is a good alternative to coronary angiography to detect CAV. In patients with a persistently high heart rate, scanners that provide high temporal resolution, such as dual-source systems, provide better image quality. Finally, in patients with insufficient acoustic window, cardiac magnetic resonance is an alternative to echocardiography to assess cardiac chamber volumes and function and to exclude acute GR and CAV in a surveillance protocol. PMID:26139361

  3. [Cardiac transplantation. Indications, delays, surveillance].

    PubMed

    Merlet, P; Benvenuti, C; Deleuze, P; Dubois-Randé, J L; Loisance, D; Castaigne, A; Cachera, J P

    1990-11-01

    The number cardiac transplantation has been dramatically increasing for the last year and the results are satisfactory regarding survival or functional capacity. The observed increase of cardiac transplantation may tend to vulgarize it. However, this intervention should be only considered in a selected group of patients who have no other option. Many reports concerned various technical approach for a clearcut determination of high and low risk population of patients with congestive heart failure. But, considering individual patients, the value of each prognostic parameter remains unresolved. Nevertheless the more discriminant parameters for the prognosis assessment are: the left ventricular ejection fraction, the NYHA class, right heart catheterization data, the functional capacity, the cardiothoracic ratio on chest X ray, the ischemic etiology of the disease. The role of neuro-hormonal determinant such as norepinephrine circulating concentration or cardiac uptake on MIBG imaging should be further investigated, especially for patients treated by ACE inhibitors or beta blockers. Contraindications for cardiac transplantation are less restrictive, nowadays. Concerning patients selected, and waiting for heart transplantation or patients non primary selected survival can be improved by adjusting medical therapy on objective efficacy criteria. PMID:2125416

  4. A multivariate analysis to assess the effect of packed red cell transfusion and the unit age of transfused red cells on postoperative complications in patients undergoing cardiac surgeries

    PubMed Central

    Makroo, Raj Nath; Hegde, Vikas; Bhatia, Aakanksha; Chowdhry, Mohit; Arora, Bhavna; Rosamma, N.L; Thakur, Uday Kumar

    2015-01-01

    Background: Transfusion of blood components and age of transfused packed red cells (PRCs) are independent risk factors for morbidity and mortality in cardiac surgeries. Materials and Methods: We retrospectively examined data of patients undergoing cardiac surgery at our institute from January 1, 2012 to September 30, 2012. Details of transfusion (autologous and allogenic), postoperative length of stay (PLOS), postoperative complications were recorded along with other relevant details. The analysis was done in two stages, in the first both transfused and nontransfused individuals and in the second only transfused individuals were considered. Age of transfused red cells as a cause of morbidity was analyzed only in the second stage. Results: Of the 762 patients included in the study, 613 (80.4%) were males and 149 (19.6%) were females. Multivariate analysis revealed that factors like the number and age of transfused PRCs and age of the patient had significant bearing upon the morbidity. Morbidity was significantly higher in the patients transfused with allogenic PRCs when compared with the patients not receiving any transfusion irrespective of the age of transfused PRCs. Transfusion of PRC of over 21 days was associated with higher postoperative complications, but not with in-hospital mortality. Conclusion: In patients undergoing cardiac surgery, allogenic blood transfusion increases morbidity. The age of PRCs transfused has a significant bearing on morbidity, but not on in-hospital mortality. Blood transfusion services will therefore have to weigh the risks and benefits of providing blood older than 21 days in cardiac surgeries. PMID:25722566

  5. Cardiac electrophysiology in mice: a matter of size

    PubMed Central

    Kaese, Sven; Verheule, Sander

    2012-01-01

    Over the last decade, mouse models have become a popular instrument for studying cardiac arrhythmias. This review assesses in which respects a mouse heart is a miniature human heart, a suitable model for studying mechanisms of cardiac arrhythmias in humans and in which respects human and murine hearts differ. Section I considers the issue of scaling of mammalian cardiac (electro) physiology to body mass. Then, we summarize differences between mice and humans in cardiac activation (section II) and the currents underlying the action potential in the murine working myocardium (section III). Changes in cardiac electrophysiology in mouse models of heart disease are briefly outlined in section IV, while section V discusses technical considerations pertaining to recording cardiac electrical activity in mice. Finally, section VI offers general considerations on the influence of cardiac size on the mechanisms of tachy-arrhythmias. PMID:22973235

  6. Serial Input Output

    SciTech Connect

    Waite, Anthony; /SLAC

    2011-09-07

    Serial Input/Output (SIO) is designed to be a long term storage format of a sophistication somewhere between simple ASCII files and the techniques provided by inter alia Objectivity and Root. The former tend to be low density, information lossy (floating point numbers lose precision) and inflexible. The latter require abstract descriptions of the data with all that that implies in terms of extra complexity. The basic building blocks of SIO are streams, records and blocks. Streams provide the connections between the program and files. The user can define an arbitrary list of streams as required. A given stream must be opened for either reading or writing. SIO does not support read/write streams. If a stream is closed during the execution of a program, it can be reopened in either read or write mode to the same or a different file. Records represent a coherent grouping of data. Records consist of a collection of blocks (see next paragraph). The user can define a variety of records (headers, events, error logs, etc.) and request that any of them be written to any stream. When SIO reads a file, it first decodes the record name and if that record has been defined and unpacking has been requested for it, SIO proceeds to unpack the blocks. Blocks are user provided objects which do the real work of reading/writing the data. The user is responsible for writing the code for these blocks and for identifying these blocks to SIO at run time. To write a collection of blocks, the user must first connect them to a record. The record can then be written to a stream as described above. Note that the same block can be connected to many different records. When SIO reads a record, it scans through the blocks written and calls the corresponding block object (if it has been defined) to decode it. Undefined blocks are skipped. Each of these categories (streams, records and blocks) have some characteristics in common. Every stream, record and block has a name with the condition that each stream, record or block name must be unique in its category (i.e. all streams must have different names, but a stream can have the same name as a record). Each category is an arbitrary length list which is handled by a 'manager' and there is one manager for each category.

  7. Body size and work output.

    PubMed

    Satyanarayana, K; Naidu, A N; Chatterjee, B; Rao, N

    1977-03-01

    The relationship between work output and anthropometric, biochemical, and socioeconomic varables was studied in 57 male industrial workers engaged in the production of detonator fuses. These workers were studied for 3 months and their daily work output was carefully measured. Work output was measured in terms of the number of fuses produced per day. Clinical and biochemical examination indicated that their current nutritional status was adequate. Among the parameters studied only body weight, height, and lean body weight were significantly correlated with work output. Body weight and lean body weight were significantly correlated (P less than 0.001) with work output even after removing the influence of height by partial correlation. Total daily work output was significantly higher (P less than 0.01) in those with higher body weight and lean body weight. The rate of work was also higher in the higher body weight group PMID:842484

  8. Primary Cardiac Allograft DysfunctionValidation of a Clinical Definition

    PubMed Central

    Dronavalli, Vamsidhar B.; Rogers, Chris A.; Banner, Nicholas R.

    2015-01-01

    Background Heart transplantation is an established treatment for advanced heart failure. Primary allograft dysfunction (PGD) is reported in up to 40% of transplants and is associated with a poor outcome. Methods As part of Heart Evaluation and Retrieval for Transplantation study, an investigation of the assessment of donor hearts for transplantation, we proposed a clinical definition for cardiac PGD comprising severely impaired systolic function affecting one or both ventricles accompanied by hypotension, low cardiac output, and high filling pressures occurring in the first 72 hours (in the absence of hyper acute rejection and technical surgical factors, such as cardiac tamponade). Here, we examine the prospective application of this definition to 290 heart transplants. We compared the clinical outcome of PGD and non-PGD cases. Results Ninety-four of 290 transplants developed PGD (32.4%). Inotrope use (score) was higher in the PGD group at 24, 48, and 72 hours after transplantation (P < 0.01). In the PGD group, there was a greater requirement for, intra-aortic balloon pump (50% vs 15%, P < 0.01), mechanical support (27% vs 0%, P < 0.01), and renal replacement therapy (61% vs 26%, P < 0.01). Intensive care stay was longer for recipients with PGD (median 14 vs 5 days, P < 0.01) and early mortality was higher (37% vs 4% at 30 days, 42% vs 8% at 1 year, P < 0.01). Conclusions In conclusion, our definition of PGD could be applied in a national multicenter study, and the cases it defined had more frequent complications and higher mortality. PMID:25742423

  9. Stimulating endogenous cardiac repair.

    PubMed

    Finan, Amanda; Richard, Sylvain

    2015-01-01

    The healthy adult heart has a low turnover of cardiac myocytes. The renewal capacity, however, is augmented after cardiac injury. Participants in cardiac regeneration include cardiac myocytes themselves, cardiac progenitor cells, and peripheral stem cells, particularly from the bone marrow compartment. Cardiac progenitor cells and bone marrow stem cells are augmented after cardiac injury, migrate to the myocardium, and support regeneration. Depletion studies of these populations have demonstrated their necessary role in cardiac repair. However, the potential of these cells to completely regenerate the heart is limited. Efforts are now being focused on ways to augment these natural pathways to improve cardiac healing, primarily after ischemic injury but in other cardiac pathologies as well. Cell and gene therapy or pharmacological interventions are proposed mechanisms. Cell therapy has demonstrated modest results and has passed into clinical trials. However, the beneficial effects of cell therapy have primarily been their ability to produce paracrine effects on the cardiac tissue and recruit endogenous stem cell populations as opposed to direct cardiac regeneration. Gene therapy efforts have focused on prolonging or reactivating natural signaling pathways. Positive results have been demonstrated to activate the endogenous stem cell populations and are currently being tested in clinical trials. A potential new avenue may be to refine pharmacological treatments that are currently in place in the clinic. Evidence is mounting that drugs such as statins or beta blockers may alter endogenous stem cell activity. Understanding the effects of these drugs on stem cell repair while keeping in mind their primary function may strike a balance in myocardial healing. To maximize endogenous cardiac regeneration, a combination of these approaches could ameliorate the overall repair process to incorporate the participation of multiple cellular players. PMID:26484341

  10. Stimulating endogenous cardiac repair

    PubMed Central

    Finan, Amanda; Richard, Sylvain

    2015-01-01

    The healthy adult heart has a low turnover of cardiac myocytes. The renewal capacity, however, is augmented after cardiac injury. Participants in cardiac regeneration include cardiac myocytes themselves, cardiac progenitor cells, and peripheral stem cells, particularly from the bone marrow compartment. Cardiac progenitor cells and bone marrow stem cells are augmented after cardiac injury, migrate to the myocardium, and support regeneration. Depletion studies of these populations have demonstrated their necessary role in cardiac repair. However, the potential of these cells to completely regenerate the heart is limited. Efforts are now being focused on ways to augment these natural pathways to improve cardiac healing, primarily after ischemic injury but in other cardiac pathologies as well. Cell and gene therapy or pharmacological interventions are proposed mechanisms. Cell therapy has demonstrated modest results and has passed into clinical trials. However, the beneficial effects of cell therapy have primarily been their ability to produce paracrine effects on the cardiac tissue and recruit endogenous stem cell populations as opposed to direct cardiac regeneration. Gene therapy efforts have focused on prolonging or reactivating natural signaling pathways. Positive results have been demonstrated to activate the endogenous stem cell populations and are currently being tested in clinical trials. A potential new avenue may be to refine pharmacological treatments that are currently in place in the clinic. Evidence is mounting that drugs such as statins or beta blockers may alter endogenous stem cell activity. Understanding the effects of these drugs on stem cell repair while keeping in mind their primary function may strike a balance in myocardial healing. To maximize endogenous cardiac regeneration, a combination of these approaches could ameliorate the overall repair process to incorporate the participation of multiple cellular players. PMID:26484341

  11. Optical output enhances flowmeter accuracy

    NASA Technical Reports Server (NTRS)

    Wolpin, E. G.

    1965-01-01

    Magnetic flowmeter with a direct-coupled optical output increases accuracy and operates independently of other system inputs. The design includes simple external adjustment and signal amplitude control.

  12. Cardiac innervation and sudden cardiac death.

    PubMed

    Fukuda, Keiichi; Kanazawa, Hideaki; Aizawa, Yoshiyasu; Ardell, Jeffrey L; Shivkumar, Kalyanam

    2015-06-01

    Afferent and efferent cardiac neurotransmission via the cardiac nerves intricately modulates nearly all physiological functions of the heart (chronotropy, dromotropy, lusitropy, and inotropy). Afferent information from the heart is transmitted to higher levels of the nervous system for processing (intrinsic cardiac nervous system, extracardiac-intrathoracic ganglia, spinal cord, brain stem, and higher centers), which ultimately results in efferent cardiomotor neural impulses (via the sympathetic and parasympathetic nerves). This system forms interacting feedback loops that provide physiological stability for maintaining normal rhythm and life-sustaining circulation. This system also ensures that there is fine-tuned regulation of sympathetic-parasympathetic balance in the heart under normal and stressed states in the short (beat to beat), intermediate (minutes to hours), and long term (days to years). This important neurovisceral/autonomic nervous system also plays a major role in the pathophysiology and progression of heart disease, including heart failure and arrhythmias leading to sudden cardiac death. Transdifferentiation of neurons in heart failure, functional denervation, cardiac and extracardiac neural remodeling has also been identified and characterized during the progression of disease. Recent advances in understanding the cellular and molecular processes governing innervation and the functional control of the myocardium in health and disease provide a rational mechanistic basis for the development of neuraxial therapies for preventing sudden cardiac death and other arrhythmias. Advances in cellular, molecular, and bioengineering realms have underscored the emergence of this area as an important avenue of scientific inquiry and therapeutic intervention. PMID:26044253

  13. Doppler echocardiography: Quantitative methods of pulsed and continuous wave cardiac doppler

    SciTech Connect

    Labovitz, A.J.; Williams, G.A.

    1985-01-01

    This book is written in workbook format and presents basic physical principles involved in the Doppler flow velocity recording in both normal and abnormal states. Formulas necessary in the computation of valve gradients, valve areas, and cardiac outputs are included.

  14. Environmentally persistent free radicals decrease cardiac function and increase pulmonary artery pressure

    PubMed Central

    Mahne, Sarah; Chuang, Gin C.; Pankey, Edward; Kiruri, Lucy; Kadowitz, Philip J.; Dellinger, Barry

    2012-01-01

    Epidemiological studies have consistently linked inhalation of particulate matter (PM) to increased cardiac morbidity and mortality, especially in at risk populations. However, few studies have examined the effect of PM on baseline cardiac function in otherwise healthy individuals. In addition, airborne PM contain environmentally persistent free radicals (EPFR) capable of redox cycling in biological systems. The purpose of this study was to determine whe