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

    Science.gov (United States)

    Chandler, Heather K; Kirsch, Roxanne

    2016-01-01

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

  2. Effects of levosimendan for low cardiac output syndrome in critically ill patients

    DEFF Research Database (Denmark)

    Koster, Geert; Wetterslev, Jørn; Gluud, Christian;

    2015-01-01

    PURPOSE: To assess the benefits and harms of levosimendan for low cardiac output syndrome in critically ill patients. METHODS: We conducted a systematic review with meta-analyses and trial sequential analyses (TSA) of randomised clinical trials comparing levosimendan with any type of control. Two...

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

    NARCIS (Netherlands)

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

    2016-01-01

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

  4. Management of perioperative low cardiac output state without extracorporeal life support: What is feasible?

    Directory of Open Access Journals (Sweden)

    Kumar Girish

    2010-01-01

    Full Text Available A transient and reversible reduction in cardiac output-low cardiac output state (LCOS often occurs following surgery for congenital heart disease. Inappropriately managed LCOS is a risk factor for increased morbidity and death. LCOS may occasionally be progressive and refractory needing a period of "myocardial rest" with extracorporeal life support (ECLS. ECLS is currently considered a routine tool available for rapid deployment in most industrialized countries. Accumulated experience and refinements in technology have led to improving survivals - discharge survivals of 35%−50%, with almost 100% survival in select groups on elective left ventricular assist device. Thus, there is an increasing trend to initiate ECLS "early or electively in the operating room" in high-risk patients. India has a huge potential need for ECLS given the large number of infants presenting late with preexisting ventricular dysfunction or in circulatory collapse. ECLS is an expensive and resource consuming treatment modality and is not a viable therapeutic option in our country. The purpose of this paper is to reiterate an anticipatory, proactive approach to LCOS: (1 methods for early detection of evolving LCOS and (2 timely initiation of individualized therapy. This paper also explores what is feasible with the refinement of "simple, conventional, inexpensive strategies" for the management of LCOS. Therapy for LCOS should be multimodal based on the type of circulation and physiology. Our approach to LCOS includes: (1 intraoperative strategies, (2 aggressive afterload reduction, (3 lusitropy, (4 exclusion of structural defects, (5 harnessing cardiopulmonary interactions, and (6 addressing metabolic and endocrine abnormalities. We have achieved a discharge survival rate of greater than 97% with these simple methods.

  5. Cardiac output during exercise

    DEFF Research Database (Denmark)

    Siebenmann, C; Rasmussen, P.; Sørensen, H.;

    2015-01-01

    Several techniques assessing cardiac output (Q) during exercise are available. The extent to which the measurements obtained from each respective technique compares to one another, however, is unclear. We quantified Q simultaneously using four methods: the Fick method with blood obtained from the...... right atrium (Q(Fick-M)), Innocor (inert gas rebreathing; Q(Inn)), Physioflow (impedance cardiography; Q(Phys)), and Nexfin (pulse contour analysis; Q(Pulse)) in 12 male subjects during incremental cycling exercise to exhaustion in normoxia and hypoxia (FiO2  = 12%). While all four methods reported a...... progressive increase in Q with exercise intensity, the slopes of the Q/oxygen uptake (VO2) relationship differed by up to 50% between methods in both normoxia [4.9 ± 0.3, 3.9 ± 0.2, 6.0 ± 0.4, 4.8 ± 0.2 L/min per L/min (mean ± SE) for Q(Fick-M), Q(Inn), QP hys and Q(Pulse), respectively; P = 0.001] and...

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

    Science.gov (United States)

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

    2016-03-01

    Myocardial contractility and relaxation are highly dependent on calcium homeostasis. Immature myocardium, as in pediatric patients, is thought to be more dependent on extracellular calcium for optimal function. For this reason, intravenous calcium chloride infusions may improve myocardial function in the pediatric patient. The objectives of this study were to report the hemodynamic changes seen after administration of continuous calcium chloride to critically ill children. We retrospectively identified pediatric patients (newborn to 17 years old) with hemodynamic instability admitted to the cardiac ICU between May 2011 and May 2012 who received a continuous infusion of calcium chloride. The primary outcome was improvement in cardiac output, assessed by arterial-mixed venous oxygen saturation (A-V) difference. Sixty-eight patients, mean age 0.87 ± 2.67 years, received a total of 116 calcium infusions. Calcium chloride infusions resulted in significant improvements in primary and secondary measures of cardiac output at 2 and 6 h. Six hours after calcium initiation, A-V oxygen saturation difference decreased by 7.4 % (32.6 ± 2.1 to 25.2 ± 2.0 %, p HR (149.1 vs 145.6 bpm p = 0.07). Urine output increased 0.66 ml/kg/h in the 8-h period after calcium initiation when compared to pre-initiation (p = 0.003). Neonates had the strongest evidence of effectiveness with other age groups trending toward significance. Calcium chloride infusions improve markers of cardiac output in a heterogenous group of pediatric patients in a cardiac ICU. Neonates appear to derive the most benefit from utilization of these infusions. PMID:26687150

  7. Management of perioperative low cardiac output state without extracorporeal life support: What is feasible?

    International Nuclear Information System (INIS)

    A transient and reversible reduction in cardiac output–low cardiac output state (LCOS) often occurs following surgery for congenital heart disease. Inappropriately managed LCOS is a risk factor for increased morbidity and death. LCOS may occasionally be progressive and refractory needing a period of “myocardial rest” with extracorporeal life support (ECLS). ECLS is currently considered a routine tool available for rapid deployment in most industrialized countries. Accumulated experience and refinements in technology have led to improving survivals – discharge survivals of 35%–50%, with almost 100% survival in select groups on elective left ventricular assist device. Thus, there is an increasing trend to initiate ECLS “early or electively in the operating room” in high-risk patients. India has a huge potential need for ECLS given the large number of infants presenting late with preexisting ventricular dysfunction or in circulatory collapse. ECLS is an expensive and resource consuming treatment modality and is not a viable therapeutic option in our country. The purpose of this paper is to reiterate an anticipatory, proactive approach to LCOS: (1) methods for early detection of evolving LCOS and (2) timely initiation of individualized therapy. This paper also explores what is feasible with the refinement of “simple, conventional, inexpensive strategies” for the management of LCOS. Therapy for LCOS should be multimodal based on the type of circulation and physiology. Our approach to LCOS includes: (1) intraoperative strategies, (2) aggressive afterload reduction, (3) lusitropy, (4) exclusion of structural defects, (5) harnessing cardiopulmonary interactions, and (6) addressing metabolic and endocrine abnormalities. We have achieved a discharge survival rate of greater than 97% with these simple methods

  8. Cardiac output monitoring

    Directory of Open Access Journals (Sweden)

    Mathews Lailu

    2008-01-01

    Full Text Available Minimally invasive and non-invasive methods of estimation of cardiac output (CO were developed to overcome the limitations of invasive nature of pulmonary artery catheterization (PAC and direct Fick method used for the measurement of stroke volume (SV. The important minimally invasive techniques available are: oesophageal Doppler monitoring (ODM, the derivative Fick method (using partial carbon dioxide (CO 2 breathing, transpulmonary thermodilution, lithium indicator dilution, pulse contour and pulse power analysis. Impedance cardiography is probably the only non-invasive technique in true sense. It provides information about haemodynamic status without the risk, cost and skill associated with the other invasive or minimally invasive techniques. It is important to understand what is really being measured and what assumptions and calculations have been incorporated with respect to a monitoring device. Understanding the basic principles of the above techniques as well as their advantages and limitations may be useful. In addition, the clinical validation of new techniques is necessary to convince that these new tools provide reliable measurements. In this review the physics behind the working of ODM, partial CO 2 breathing, transpulmonary thermodilution and lithium dilution techniques are dealt with. The physical and the physiological aspects underlying the pulse contour and pulse power analyses, various pulse contour techniques, their development, advantages and limitations are also covered. The principle of thoracic bioimpedance along with computation of CO from changes in thoracic impedance is explained. The purpose of the review is to help us minimize the dogmatic nature of practice favouring one technique or the other.

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

    Directory of Open Access Journals (Sweden)

    Sabzi Feridoun

    2015-03-01

    Full Text Available 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.

  10. HEART FAILURE WITH LOW CARDIAC OUTPUT AND RISK OF DEVELOPMENT OF LESIONS IN THE CEREBRAL WHITE MATTER

    OpenAIRE

    2005-01-01

    Aim: Diminished cardiac output can lead to the development of white matter lesions. White matter lesions are related to cognitive impairment, stroke risk and vascular death, yet the precise aetiology is uncertain. Methods: In this study we recruited 130 patients attending our medicine and neurology outpatient department, and divided them into those with a history of heart failure (n:24), atrial fibrillation (n:26), and those with atherosclerotic risk factors (n:80). The patients without low o...

  11. Regional blood flow distribution in dog during induced hypotension and low cardiac output. Spontaneous breathing versus artificial ventilation.

    OpenAIRE

    Viires, N; Sillye, G; Aubier, M.; Rassidakis, A; Roussos, C

    1983-01-01

    Respiratory muscle blood flow and organ blood flow was studied in two groups of dogs with radioactively labeled microspheres to assess the influence of the working respiratory muscles on the regional distribution of blood flow when arterial pressure and cardiac output were lowered by pericardial tamponade. In one group (n = 6), the dogs were paralyzed and mechanically ventilated (Mv), while in the other (n = 6), they were left to breathe spontaneously (Sb). Cardiac output fell to 30% of contr...

  12. Methods in pharmacology: measurement of cardiac output

    OpenAIRE

    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 pul...

  13. Low cardiac output as physiological phenomenon in hibernating, free-ranging Scandinavian brown bears (Ursus arctos) - an observational study

    DEFF Research Database (Denmark)

    Jørgensen, Peter Godsk; Arnemo, Jon; Swenson, Jon E;

    2014-01-01

    cardiac function associated with metabolic depression in the hibernating vs. active states in free-ranging Scandinavian brown bears. METHODS: We performed echocardiography on seven free-ranging brown bears in Dalarna, Sweden, anesthetized with medetomidine-zolazepam-tiletamine-ketamine during winter....... CONCLUSION: Free-ranging brown bears demonstrate hemodynamics comparable to humans during active state, whereas during hibernation, we documented extremely low-flow hemodynamics. Understanding these physiological changes in bears may help to gain insight into the mechanisms of cardiogenic shock and heart...

  14. Comparison of cardiac output measurement techniques

    DEFF Research Database (Denmark)

    Espersen, K; Jensen, E W; Rosenborg, D; Thomsen, J K; Eliasen, Kirstin; Olsen, Niels Vidiendal; Kanstrup, I L

    1995-01-01

    Simultaneously measured cardiac output obtained by thermodilution (TD), transcutaneous suprasternal ultrasonic Doppler (DOP), CO2-rebreathing (CR) and the direct Fick method (FI) were compared in eleven healthy subjects in a supine position (SU), a sitting position (SI), and during sitting exercise...

  15. [Cardiac output monitoring by impedance cardiography in cardiac surgery].

    Science.gov (United States)

    Shimizu, H; Seki, S; Mizuguchi, A; Tsuchida, H; Watanabe, H; Namiki, A

    1990-04-01

    The cardiac output monitoring by impedance cardiography, NCCOM3, was evaluated in adult patients (n = 12) who were subjected to coronary artery bypass grafting. Values of cardiac output measured by impedance cardiography were compared to those by the thermodilution method. Changes of base impedance level used as an index of thoracic fluid volume were also investigated before and after cardiopulmonary bypass (CPB). Correlation coefficient (r) of the values obtained by thermodilution with impedance cardiography was 0.79 and the mean difference was 1.29 +/- 16.9 (SD)% during induction of anesthesia. During the operation, r was 0.83 and the mean difference was -14.6 +/- 18.7%. The measurement by impedance cardiography could be carried out through the operation except when electro-cautery was used. Base impedance level before CPB was significantly lower as compared with that after CPB. There was a negative correlation between the base impedance level and central venous pressure (CVP). No patients showed any signs suggesting lung edema and all the values of CVP, pulmonary artery pressure and blood gas analysis were within normal ranges. From the result of this study, it was concluded that cardiac output monitoring by impedance cardiography was useful in cardiac surgery, but further detailed examinations will be necessary on the relationship between the numerical values of base impedance and the clinical state of the patients. PMID:2362347

  16. Methods and apparatus for determining cardiac output

    Science.gov (United States)

    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.

  17. Peripheral vasodilatation determines cardiac output in exercising humans

    DEFF Research Database (Denmark)

    Bada, A A; Svendsen, J H; Secher, N H; Saltin, B; Mortensen, S P

    In dogs, manipulation of heart rate has no effect on the exercise-induced increase in cardiac output. Whether these findings apply to humans remain uncertain, because of the large differences in cardiovascular anatomy and regulation. To investigate the role of heart rate and peripheral...... arterial ATP infusion at rest. Exercise and ATP infusion increased cardiac output, leg blood flow and vascular conductance (P <0.05), whereas cerebral perfusion remained unchanged. During atrial pacing increasing heart rate by up to 54 beats min(−1), cardiac output did not change in any of the three...... demonstrate that the elevated cardiac output during steady-state exercise is regulated by the increase in skeletal muscle blood flow and venous return to the heart, whereas the increase in heart rate appears to be secondary to the regulation of cardiac output....

  18. Invasive and non-invasive methods for cardiac output measurement

    OpenAIRE

    Lavdaniti M.

    2008-01-01

    The hemodynamic status monitoring of high-risk surgical patients and critically ill patients inIntensive Care Units is one of the main objectives of their therapeutic management. Cardiac output is one of the mostimportant parameters for cardiac function monitoring, providing an estimate of whole body perfusion oxygen deliveryand allowing for an understanding of the causes of high blood pressure. The purpose of the present review is thedescription of cardiac output measurement methods as prese...

  19. Issues in methods and measurement of thermodilution cardiac output.

    Science.gov (United States)

    Sommers, M S; Woods, S L; Courtade, M A

    1993-01-01

    Criterion-related validity of the thermodilution cardiac output technique for cardiac output measurement has to have a high correlation (r = .91 to .98) with the direct Fick method, the gold standard of cardiac output measurement. Issues that can affect validity of the measurements include the position of the pulmonary artery catheter, the rate of injection of the indicator solution, the volume and temperature of the injectate, the timing of the injection of indicator solution during the respiratory cycle, the position of the subject, and the presence of concomitant infusions. Variation in measurement can be limited by considering the delivery system for the indicator solution, by recording time-temperature cardiac output curves, and by considering normal biologic variations. PMID:8337161

  20. Mini invasive hemodynamic monitoring: from arterial pressure to cardiac output

    OpenAIRE

    GIORGIO DELLA ROCCA; MAURIZIO CECCONI; MARIA GABRIELLA COSTA

    2008-01-01

    To evaluate the Cardiac Output (CO) the standard invasive pulmonary artery catheter (PAC) is considered today the gold standard. The major criticism to the PAC is that its level of invasiveness is not supported by an improvement in patient's outcome. The interest to lesser and lesser invasive techniques is high. Therefore, the alternative techniques have been recently developed.Cardiac Output can be monitored continuously by different devices that analyze the arterial waveform to track change...

  1. A Numerical Investigation of Heat Transfer Cardiac Output Measurements

    OpenAIRE

    Fotheringham, P.; A R Gourlay; McKee, S.; Andrews, S

    2005-01-01

    Measurement of cardiac output is often investigated using a technique based on hot-film anemometry. Here, we discuss a modification to hot-film anemometry, which involves a cylindrical heating element mounted flush on the surface of a typical Swan-Ganz catheter. In contrast to traditional thermodilution, the method discussed here has the potential to allow continuous monitoring of cardiac output.This paper demonstrates that there is a simple approximate relationship between the power input to...

  2. Modelflow underestimates cardiac output in heat-stressed individuals

    DEFF Research Database (Denmark)

    Shibasaki, Manabu; Wilson, Thad E; Bundgaard-Nielsen, Morten; Seifert, Thomas; Secher, Niels H; Crandall, Craig G

    2011-01-01

    Modelflow accurately tracks thermodilution-derived cardiac outputs during whole body heat stress. Acute changes of cardiac output were accomplished via lower-body negative pressure (LBNP) during normothermic and heat-stressed conditions. In nine healthy normotensive subjects, arterial pressure was measured...... similar with cardiac outputs measured by thermodilution (6.4 ± 0.8 l/min). The subsequent reduction in cardiac output during LBNP was also similar among these methods. Whole body heat stress elevated internal temperature from 36.6 ± 0.3 to 37.8 ± 0.4°C and increased cardiac output from 6.4 ± 0.8 to 10.......9 ± 2.0 l/min when evaluated with thermodilution (P <0.001). However, the increase in cardiac output estimated from the Modelflow method for both arterial cannulation (2.3 ± 1.1 l/min) and Finometer (1.5 ± 1.2 l/min) was attenuated compared with thermodilution (4.5 ± 1.4 l/min, both P <0.01). Finally...

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

    Energy Technology Data Exchange (ETDEWEB)

    Schreiner, M.S.; Leksell, L.G.; Neufeld, G.R. (Univ. of Pennsylvania School of Medicine, Philadelphia (USA))

    1989-10-01

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

  4. Determination of myocardial energetic output for cardiac rhythm pacing

    OpenAIRE

    Heřman, Dalibor; Převorovská, Světlana; Maršík, František

    2007-01-01

    This research is aimed to the determination of the changes in the cardiac energetic output for three different modes of cardiac rhythm pacing. The clinical investigation of thirteen patients with the permanent dual-chamber pacemaker implantation was carried out. The patients were taken to echocardiography examination conducted by way of three pacing modes (AAI, VVI and DDD). The myocardial energetic parameters—the stroke work index (SWI) and the myocardial oxygen consumption (MVO2) are not di...

  5. Relationship between cardiac output and effective renal plasma flow in patients with cardiac disease

    Energy Technology Data Exchange (ETDEWEB)

    McGriffin, D.; Tauxe, W.N.; Lewis, C.; Karp, R.; Mantle, J.

    1984-12-01

    The relationship between effective renal plasma flow (ERPF) and cardiac output was examined in 46 patients (22 with congestive heart failure and 24 following cardiac surgical procedures) by simultaneously measuring the global ERPF by the single-injection method and cardiac output by the thermodilution method. Of the patients in the heart-failure group, 21 also had pulmonary artery end diastolic pressure (PAEDP) recorded at the same time. ERPF and cardiac output were found to be related by the regression equations: cardiac output = 2.08 + 0.0065 ERPF (r, 080), with a SE of estimate of 0.81 l/min. ERPF and PAEDP were related by the regression equation: PAEDP = 42.02 - 0.0675 ERPF (r, 0.86), with a SE of estimate of 5.5 mm Hg. ERPF may be a useful noninvasive method of estimating cardiac output if it is known that no intrinsic kidney disease is present, and if the error of 0.81 l/min (1 SE of estimate) is within the range of clinical usefulness. The error is principally attributable to the determination of cardiac output by the thermodilution method.

  6. Pulse contour-derived cardiac output in hemodialysis patients

    DEFF Research Database (Denmark)

    Cordtz, Joakim; Ladefoged, Soeren D

    2010-01-01

    analysis, namely the Finometer monitor (FNM) for further use on patients dialyzing on a central vascular catheter. Fifty simultaneous cardiac output measurements were obtained during hemodialysis sessions in 25 patients. The internal variability of the FNM measurements was assessed by comparing 24 pairs of...

  7. Pulse contour-derived cardiac output in hemodialysis patients

    DEFF Research Database (Denmark)

    Cordtz, Joakim; Ladefoged, Soeren D

    2010-01-01

    Reliable methods for cardiac output determination are essential for studying the pathophysiology of intradialytic hypotension. Use of the current gold standard, the Transonic monitor, requires an arteriovenous fistula. We wished to verify the accuracy of a method based on finger pulse contour...

  8. Cardiac output and vasodilation in the vasovagal response

    DEFF Research Database (Denmark)

    Wieling, Wouter; Jardine, David L; de Lange, Frederik J;

    2016-01-01

    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...

  9. Invasive and non-invasive methods for cardiac output measurement

    Directory of Open Access Journals (Sweden)

    Lavdaniti M.

    2008-01-01

    Full Text Available The hemodynamic status monitoring of high-risk surgical patients and critically ill patients inIntensive Care Units is one of the main objectives of their therapeutic management. Cardiac output is one of the mostimportant parameters for cardiac function monitoring, providing an estimate of whole body perfusion oxygen deliveryand allowing for an understanding of the causes of high blood pressure. The purpose of the present review is thedescription of cardiac output measurement methods as presented in the international literature. The articles documentthat there are many methods of monitoring the hemodynamic status of patients, both invasive and non-invasive, themost popular of which is thermodilution. The invasive methods are the Fick method and thermodilution, whereasthe non-invasive methods are oeshophaegeal Doppler, transoesophageal echocardiography, lithium dilution, pulsecontour, partial CO2 rebreathing and thoracic electrical bioimpedance. All of them have their advantages and disadvantages,but thermodilution is the golden standard for critical patients, although it does entail many risks. The idealsystem for cardiac output monitoring would be non-invasive, easy to use, reliable and compatible in patients. A numberof research studies have been carried out in clinical care settings, by nurses as well as other health professionals, for thepurpose of finding a method of measurement that would have the least disadvantages. Nevertheless, the thermodilutiontechnique remains the most common approach in use today.

  10. Temporary epicardial left ventricular and biventricular pacing improves cardiac output after cardiopulmonary bypass

    Directory of Open Access Journals (Sweden)

    García-Bengochea Jose B

    2012-10-01

    Full Text Available Abstract Background To evaluate, with different pacing modes, acute changes in left ventricular systolic function, obtained by continuous cardiac output thermodilution in various subsets of patients undergoing cardiopulmonary bypass surgery. Increments of mean arterial pressure and cardiac output were considered the end point. Methods Fifty cases electively submitted to cardiac surgery were analyzed. Isolated valve surgery 62%, coronary revascularization 30% and 8% mixed disease. Left ventricular ejection fraction was preserved in 50%,36% had moderate depression,(EF 36%-50% whereas 14% had severe depression (EF  Results Right atrium-right ventricular pacing, decreased significantly mean arterial pressure and cardiac output (2.3% in the overall population and in the subgroups studied. Right atrium-left ventricle, increased mean arterial pressure and cardiac output in 79% of patients and yielded cardiac output increments of 7.5% (0.40 l/m in the low ejection fraction subgroup and 7.3% (0.43 l/m in the left bundle branch block subset. In atrial fibrillation patients, left ventricular and biventricular pacing produced a significant increase in cardiac output 8.5% (0.39 l/min and 11.6% (0.53 l/min respectively. The dP/dt max increased significantly with both modes (p = 0.021,p = 0.028. Conclusion Right atrial-right ventricular pacing generated adverse hemodynamic effects. Right atrium-left ventricular pacing produced significant CO improvement particularly in cases with depressed ventricular function and left bundle branch block. The greatest increments were observed with left ventricular or biventricular pacing in atrial fibrillation with depressed ejection fraction.

  11. Cardiac Output Measurement in Patients with an Implanted Pacemaker

    Czech Academy of Sciences Publication Activity Database

    Vondra, Vlastimil; Halámek, Josef; Viščor, Ivo; Jurák, Pavel; Novák, M.

    Danvers : Institute of Electrical and Electronics Engineers, Inc., 2007, s. 916-918. ISBN 978-1-4244-0787-3. ISSN 1557-170X. [Annual International Conference of the IEEE Engineering in Medicine and Biology Society /29./. Lyon (FR), 23.08.2007-26.08.2007] R&D Projects: GA ČR GA102/06/0136 Institutional research plan: CEZ:AV0Z20650511 Keywords : cardiac output measurement * implanted pacemaker Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery

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

    OpenAIRE

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

    2010-01-01

    Abstract The application of positive end expiratory pressure (PEEP) in mechanically ventilated (MV) patients with acute respiratory distress syndrome (ARDS) decreases cardiac output (CO). Accurate measurement of CO is highly invasive and is not ideal for all MV critically ill patients. However, the link between the PEEP used in MV, and CO provides an opportunity to assess CO via MV therapy and other existing measurements, creating a CO measure without further invasiveness. This paper examines...

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

    International Nuclear Information System (INIS)

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

  14. Assessment of cardiac output changes using a modified FloTrac/Vigileo™ algorithm in cardiac surgery patients

    OpenAIRE

    Senn, Alban; Button, Danny; Zollinger, Andreas; Hofer, Christoph K

    2009-01-01

    Introduction The FloTrac/Vigileo™ (Edwards Lifesciences, Irvine, CA, USA) allows pulse pressure-derived cardiac output measurement without external calibration. Software modifications were performed in order to eliminate initially observed deficits. The aim of this study was to assess changes in cardiac output determined by the FloTrac/Vigileo™ system (FCO) with an initially released (FCOA) and a modified (FCOB) software version, as well as changes in cardiac output from the PiCCOplus™ system...

  15. Determination of myocardial energetic output for cardiac rhythm pacing.

    Science.gov (United States)

    Herman, Dalibor; Prevorovská, Svetlana; Marsík, Frantisek

    2007-12-01

    This research is aimed to the determination of the changes in the cardiac energetic output for three different modes of cardiac rhythm pacing. The clinical investigation of thirteen patients with the permanent dual-chamber pacemaker implantation was carried out. The patients were taken to echocardiography examination conducted by way of three pacing modes (AAI, VVI and DDD). The myocardial energetic parameters-the stroke work index (SWI) and the myocardial oxygen consumption (MVO2) are not directly measurable, however, their values can be determined using the numerical model of the human cardiovascular system. The 24-segment hemodynamical model (pulsating type) of the human cardiovascular system was used for the numerical simulation of the changes of myocardial workload for cardiac rhythm pacing. The model was fitted by well-measurable parameters for each patient. The calculated parameters were compared using the two-tailed Student's test. The differences of SWI and MVO2 between the modes AAI and VVI and the modes DDD and VVI are statistically significant (P0.05). PMID:18080208

  16. The Unpredictable Effect of Changing Cardiac Output on Hypoxemia after Acute Pulmonary Thromboembolism

    OpenAIRE

    Tsang, John Y.C.; Wayne J E Lamm; Blazej Neradilek; Polissar, Nayak L.; Michael P. Hlastala

    2008-01-01

    Previous studies reported that the degree of hypoxemia following acute pulmonary thromboembolism (APTE) was highly variable and that its mechanism was mainly due to the creation of many high and low ventilation/perfusion (V/Q) units, as a result of the heterogeneous regional blood flow (Q) caused by embolic obstruction. We studied the effect of changing cardiac output (Qt) on gas exchange after APTE in 5 embolized piglets (23 ± 3 Kg), using Dobutamine intermittently at approximately 20 µg/kg/...

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

    Directory of Open Access Journals (Sweden)

    Hann Christopher E

    2010-11-01

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

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

    Science.gov (United States)

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

    2010-01-01

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

  19. Lack of agreement between esophageal doppler cardiac output measurements and continuous pulse contour analysis during off-pump cardiac surgery

    Directory of Open Access Journals (Sweden)

    H. V. Groesdonk

    2010-03-01

    Full Text Available Objective: Transesophageal echo-Doppler cardiac output as well as arterial pulse contour analyses cardiac output are increasingly used for cardiac output monitoring. No data are available whether both techniques may be used interchangeably in patients undergoing cardiac surgery. Design: Prospective, observational study Setting: Operating rooms of a university affiliated hospital. Patients: 30 patients undergoing elective coronary artery bypass grafting surgery.Interventions: NoneMeasurements: 900 paired cardiac output measurements were obtained by pulse contour analysis following transpulmonary thermodilution equilibration by the PiCCO system (PiCCO, Pulsion, Munich, Germany and by the HemoSonic esophageal doppler monitor (HemoSonic 100; Arrow International, Reading, PA. Measurements were performed within the first hour after induction of anesthesia. Results: Bland-Altman analysis of the complete data set showed a mean difference (bias of - 0.12 l/min (95% CI -0.06 to -0.18 with limits of agreement + 1.8 l/min to -1.6 l/min (upper 95% CI 1.78 to 1.98; lower 95% CI -1.74 to -1.54, the percentage error was + 37% to -44.5%. Transesophageal echo-Doppler cardiac output closely correlated (r = 0.75, p < 0.0001 with pulse-contour analyses cardiac output. Conclusions: Several studies have shown the accuracy of calibrated pulse contour cardiac output measurements in patients undergoing cardiac surgery. Thus, the present data question the reliability of transesophageal echo-Doppler derived cardiac output measurements in this setting and may have implications for using transesophageal echo-Doppler during goal-directed hemodynamic optimization.

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

    Science.gov (United States)

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

    2016-06-01

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

  1. Non-invasive cardiac output monitoring in neonates using bioreactance: a comparison with echocardiography.

    LENUS (Irish Health Repository)

    Weisz, Dany E

    2012-01-01

    Non-invasive cardiac output monitoring is a potentially useful clinical tool in the neonatal setting. Our aim was to evaluate a new method of non-invasive continuous cardiac output (CO) measurement (NICOM™) based on the principle of bioreactance in neonates.

  2. Kredsløbsmonitorering af kritisk syge patienter med "pulse contour cardiac output"-systemet

    DEFF Research Database (Denmark)

    Afshari, Arash; Perner, Anders; Bonde, Jan

    2006-01-01

    The Pulse Contour Cardiac Output (PiCCO) monitoring system measures cardiac output with high precision and accuracy. The system may replace the pulmonary artery catheter in most critically ill patients because the rate of serious complications may be lower. Whether the use of dynamic or static fl...

  3. Kredsløbsmonitorering med lithium dilution cardiac output-systemet

    DEFF Research Database (Denmark)

    Christiansen, Christian; Hostrup, Anette; Tønnesen, Else;

    2008-01-01

    The lithium dilution cardiac output (LiDCO) system measures cardiac output beat-to-beat with high precision. The system is based on an arterial pulse power analysis which is calibrated every eight hours with a small non-pharmacological dose of lithium. The system is minimally invasive; it requires...

  4. Simultaneous cardiac output and regional myocardial perfusion determination with PET and nitrogen 13 ammonia

    DEFF Research Database (Denmark)

    Hove, Jens D; Kofoed, Klaus F; Wu, Hsiao M;

    2003-01-01

    The purpose of this study was to evaluate the possibility of measuring cardiac output during positron emission tomography (PET) examination of myocardial perfusion with nitrogen 13 ammonia.......The purpose of this study was to evaluate the possibility of measuring cardiac output during positron emission tomography (PET) examination of myocardial perfusion with nitrogen 13 ammonia....

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

    Science.gov (United States)

    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

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

    OpenAIRE

    Silke, Bernard

    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 mo...

  7. Lack of agreement and trending ability of the endotracheal cardiac output monitor compared with thermodilution

    DEFF Research Database (Denmark)

    Møller-Sørensen, H; Hansen, K L; Ostergaard, M; Andersen, L W; Møller, Kirsten

    2012-01-01

    BACKGROUND: Minimally invasive monitoring systems of central haemodynamics are gaining increasing popularity. The present study investigated the precision of the endotracheal cardiac output monitor (ECOM) system and its agreement with pulmonary artery catheter thermodilution (PAC TD) for measuring...

  8. Evaluation of a new arterial pressure-based cardiac output device requiring no external calibration

    OpenAIRE

    Amann Matthias; Trabold Benedikt; Schweiger Stefan; Keyl Cornelius; Bele Sylvia; Prasser Christopher; Welnhofer Julia; Wiesenack Christoph

    2007-01-01

    Abstract Background Several techniques have been discussed as alternatives to the intermittent bolus thermodilution cardiac output (COPAC) measurement by the pulmonary artery catheter (PAC). However, these techniques usually require a central venous line, an additional catheter, or a special calibration procedure. A new arterial pressure-based cardiac output (COAP) device (FloTrac™, Vigileo™; Edwards Lifesciences, Irvine, CA, USA) only requires access to the radial or femoral artery using a s...

  9. The decrease of cardiac chamber volumes and output during positive-pressure ventilation

    DEFF Research Database (Denmark)

    Kristensen, Kasper Kyhl; Ahtarovski, Kiril Aleksov; Iversen, Kasper;

    2013-01-01

    effect of PPV on the central circulation by studying cardiac chamber volumes with cardiac magnetic resonance imaging (CMR). We hypothesized that PPV lowers cardiac output (CO) mainly via the Frank-Starling relationship. In 18 healthy volunteers, cardiac chamber volumes and flow in aorta and the pulmonary......Positive-pressure ventilation (PPV) is widely used for treatment of acute cardiorespiratory failure, occasionally at the expense of compromised cardiac function and arterial blood pressure. The explanation why has largely rested on interpretation of intracardiac pressure changes. We evaluated the...... artery were measured by CMR during PPV levels of 0, 10, and 20 cmH2O applied via a respirator and a face mask. All cardiac chamber volumes decreased in proportion to the level of PPV. Following 20-cmH2O PPV, the total diastolic and systolic cardiac volumes (±SE) decreased from 605 (±29) ml to 446 (±29...

  10. Determination of myocardial energetic output for cardiac rhythm pacing

    Czech Academy of Sciences Publication Activity Database

    Heřman, D.; Převorovská, Světlana; Maršík, František

    2007-01-01

    Roč. 7, č. 4 (2007), s. 156-161. ISSN 1567-8822 R&D Projects: GA ČR GA106/03/1073 Institutional research plan: CEZ:AV0Z20760514 Keywords : heart arrhythmia * cardiac pacing modes * numerical simulation Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery

  11. Validation of noninvasive pulse contour cardiac output using finger arterial pressure in cardiac surgery patients requiring fluid therapy

    NARCIS (Netherlands)

    Hofhuizen, C.M.; Lansdorp, B.; Hoeven, J.G. van der; Scheffer, G.J.; Lemson, J.

    2014-01-01

    INTRODUCTION: Nexfin (Edwards Lifesciences, Irvine, CA) allows for noninvasive continuous monitoring of blood pressure (ABPNI) and cardiac output (CONI) by measuring finger arterial pressure (FAP). To evaluate the accuracy of FAP in measuring ABPNI and CONI as well as the adequacy of detecting chang

  12. Validation of noninvasive pulse contour cardiac output using finger arterial pressure in cardiac surgery patients requiring fluid therapy

    NARCIS (Netherlands)

    Hofhuizen, Charlotte; Lansdorp, Benno; Hoeven, van der Johannes G.; Scheffer, Gert-Jan; Lemson, Joris

    2014-01-01

    Introduction Nexfin (Edwards Lifesciences, Irvine, CA) allows for noninvasive continuous monitoring of blood pressure (ABPNI) and cardiac output (CONI) by measuring finger arterial pressure (FAP). To evaluate the accuracy of FAP in measuring ABPNI and CONI as well as the adequacy of detecting change

  13. Valve area and cardiac output in aortic stenosis: quantification by magnetic resonance velocity mapping

    DEFF Research Database (Denmark)

    Søndergaard, Lise; Hildebrandt, P; Lindvig, K;

    1993-01-01

    Valve area and cardiac output were determined with magnetic resonance (MR) velocity mapping in 12 patients with aortic stenosis. Heart catheterization, Doppler echocardiography, and indicator dilution were performed for comparison. Left ventricle could be catheterized in only nine patients; in...... material, MR measured a mean area of 1.1 cm2 compared with 1.2 cm2 derived from Doppler echocardiography data, with a mean difference of 0.1 cm2 and [-0.5, +0.6] cm2 as limits of agreement. In 11 patients the cardiac output was quantified by MR to a mean of 4.9 L/min and by indicator dilution to 5.0 L......--the valvular area and the cardiac output--may be quantified, MR has potential to become a clinical tool in assessment of severity in aortic stenosis....

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

    DEFF Research Database (Denmark)

    Calbet, J A L; Mortensen, Stefan; Munch, G D W;

    2016-01-01

    To determine the accuracy and precision of constant infusion transpulmonary thermodilution cardiac output (CITT-Q) assessment during exercise in humans, using indocyanine green (ICG) dilution and bolus transpulmonary thermodilution (BTD) as reference methods, cardiac output (Q) was determined at...... rest and during incremental one- and two-legged pedaling on a cycle ergometer, and combined arm cranking with leg pedaling to exhaustion in 15 healthy men. Continuous infusions of iced saline in the femoral vein (n = 41) or simultaneously in the femoral and axillary (n = 66) veins with determination of......: 6.1-11.1%). In conclusion, cardiac output can be precisely and accurately determined with constant infusion transpulmonary thermodilution in exercising humans....

  15. Techniques of cardiac output measurement during liver transplantation: arterial pulse wave versus thermodilution

    DEFF Research Database (Denmark)

    Nissen, P.; Lieshout, J.J. van; Novovic, S.;

    2009-01-01

    In this study, we compared continuous cardiac output (CO) obtained from the femoral arterial pressure by simulation of an aortic input impedance model [model-simulated cardiac output (MCO)] to thermodilution cardiac output (TDCO) determined by bolus injection during liver transplantation. Both...... variables were measured in 39 adult patients (13 females) every 10th minute during liver transplant surgery. Paired measurements were compared during the 4 phases of surgery-dissection, anhepatic phase, early reperfusion (the first 15 minutes after reperfusion), and late reperfusion (15-60 minutes after......, and the mutual correlation coefficient was 0.812 (P < 0.001). This study indicates that during liver transplantation surgery, MCO reflects TDCO throughout the operation. Thus, for CO, this less invasive method appears to provide a reliable uninterrupted measurement during orthotopic liver...

  16. Cardiac output determined by echocardiography in patients with cirrhosis: comparison with the indicator dilution technique

    DEFF Research Database (Denmark)

    Andersen, Ulrik B; Møller, Søren; Bendtsen, Flemming; Henriksen, Jens H

    2003-01-01

    technique (CO(I)). METHODS: Twelve patients with cirrhosis were studied. CO(d) was measured as the spatial mean velocity of the left ventricular outflow tract, multiplied by the cross-sectional area and the heart rate. CO(I) was determined by the standard indicator dilution technique after injection of 125I......BACKGROUND/AIMS: Measurement of cardiac output in hyperkinetic patients with cirrhosis by Doppler echocardiography is increasingly reported, but has not been validated. We have compared simultaneous measurements of cardiac output by Doppler echocardiography (CO(d)) and by the indicator dilution...... with the Doppler technique. CONCLUSION: Doppler measurements of cardiac output in groups of patients with cirrhosis are accurate with respect to the group mean, but marked disagreements of over- and underestimation were seen in individual patients. The reproducibility of the Doppler technique is...

  17. Measurement of cardiac output by dynamic computed transmission tomography. Comparison with thermodilution method

    Energy Technology Data Exchange (ETDEWEB)

    Nakajima, Yoshiaki; Yoshino, Futoshi; Ootani, Yukihiro; Kishimoto, Kinya; Takahashi, Ryuji

    1989-05-01

    The capacity of the new computed tomography (CT) instrument with excellent time resolution to measure cardiac output was explored. Dynamic scans of serial one-second images were performed at the middle section of left ventricle for 28 sec. We injected a bolus of 0.3 ml/kg angiografin for 2 sec or 0.4 ml/kg angiografin for 4 sec into the inferior vena cava. The regions of interest were set in the left ventricular cavity and thoracic aorta. Cardiac output was calculated by applying indicator dilution principles. The results were compared with those obtained by thermodilution. The CT results by using 2 sec 0.3 ml/kg angiografin correlated well (r=0.91, p<0.001) with those of thermodilution. This study indicates the utililty of dynamic CT for estimation of cardiac output. (author).

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

    OpenAIRE

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

    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, maxima...

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

    OpenAIRE

    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...

  20. High-output cardiac failure secondary to multiple vascular malformations in the liver: case report

    Energy Technology Data Exchange (ETDEWEB)

    Spaner, S.; Demeter, S. [Univ. of Alberta, Dept. of Radiology and Diagnostic Imaging, Edmonton, Alberta (Canada); Lien, D. [Univ. of Alberta, Dept. of Pulmonary Medicine, Edmonton, Alberta (Canada); Shapiro, J. [Univ. of Alberta, Dept. of Surgery, Edmonton, Alberta (Canada); McCarthy, M.; Raymond, G. [Univ. of Alberta, Dept. of Radiology and Diagnostic Imaging, Edmonton, Alberta (Canada)

    2001-08-01

    High-output cardiac failure is associated with several systemic illnesses, including hyperthyroidism, thiamine deficiency, severe anemia, multiple myeloma, Paget's disease of bone and Osler-Weber-Rendu syndrome. We present an unusual case of a woman with high-output cardiac failure as a result of multiple arteriovenous fistulas in the liver, most likely representing an unusual variant of Osler-Weber-Rendu syndrome (i.e., no other telangiectasias or a family history of vascular malformations was demonstrated). (author)

  1. Cardiac output determination during intravenous cardioangiography using X-ray fluorescence analysis

    Energy Technology Data Exchange (ETDEWEB)

    Boijsen, M.; Goss, F.; Jacobsson, L.; Lamm, C.; Schlossmann, D.; Bjoerneld, L.; Tylen, U.

    Cardiac output was determined with an indicator dilution technique during digital venous angiography of the left ventricle in 11 patients. The contrast medium injected into the right atrium was used as indicator. During and after the injection of contrast medium one blood sample per second was obtained through a catheter placed in the descending aorta. The samples were analyzed for iodine content with X-ray fluorescence analysis and cardiac output determined ad modum Stewart-Hamilton. Thermodilution was used as a reference method. The results indicate that the indicator dilution method with the use of contrast medium might be used for calibration of videodensitometric methods for blood flow measurements.

  2. Dye-dilution cardiac output without blood withdrawal in the conscious rabbit

    International Nuclear Information System (INIS)

    Cardiac output can be measured in the conscious rabbit without blood withdrawal by use of a modified dye-dilution method. Blood flows continuously from the central ear artery through a Silastic catheter that passes through a modified cuvette lumen and back into an ear vein. Blood flow through this shunt was 1.5 ml/min. This modified technique was evaluated by comparison with a simultaneously performed cardiac output measurement using radioactive microspheres and by making consecutive dye-dilution measurements at short time intervals. A correlation coefficient of 0.96 was obtained when comparing dye-dilution and microsphere cardiac outputs. The difference between 11 paired measurements was 7.09 +- 5.24% (mean +- SD). Consecutive outputs measured within 3 min of each other by the flow-through technique had a correlation coefficient of 0.99 and a difference between the first and second determinations of 3.52 +- 2.38%. The method permits dye-dilution cardiac output measurement in the conscious rabbit while avoiding the potential error caused by blood withdrawal from small animals

  3. A multiple-input multiple-output system for modeling the cardiac dynamics.

    Science.gov (United States)

    Monzon, Jorge E; Picaza, Carlos Alvarez; Pisarello, Maria I

    2011-01-01

    We describe the dynamics of the cardiovascular system by finding the input-output relationships in the state space of a functional cardiac model, based on state equations and observability criteria of control theory. The unit step response of the multiple-input multiple-output system model illustrates the damping effect of the arterial wall to the pulsatility of the heart. Our results show that hypertensive patients exhibit a lower inertia of the blood flow. PMID:22254491

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

    Czech Academy of Sciences Publication Activity Database

    Horn, P.; Ošťádal, P.; Ošťádal, Bohuslav

    2015-01-01

    Roč. 64, č. 2 (2015), s. 203-207. ISSN 0862-8408 Institutional support: RVO:67985823 Keywords : cardiac output * cycling * heart rate * stroke volume Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery Impact factor: 1.293, year: 2014

  5. Phlebotomy eliminates the maximal cardiac output response to six weeks of exercise training

    DEFF Research Database (Denmark)

    Bonne, Thomas Christian; Doucende, Gregory; Flück, Daniela;

    2014-01-01

    With this study we tested the hypothesis that six weeks of endurance training increases maximal cardiac output (Qmax) relatively more by elevating blood volume (BV) than by inducing structural and functional changes within the heart. Nine healthy but untrained volunteers (VO2max 47 ± 5 ml.min(-1)...

  6. A-V Delay Versus Cardiac Output Measured with Thorax Bioimpedance Monitor

    Czech Academy of Sciences Publication Activity Database

    Vondra, Vlastimil; Halámek, Josef; Viščor, Ivo; Jurák, Pavel; Novák, M.; Lipoldová, J.

    2008-01-01

    Roč. 6, č. 1 (2008), s. 73. ISSN 1556-7451. [World Congress on Heart Disease /14./. 26.07.2008-29.07.2008, Toronto] Institutional research plan: CEZ:AV0Z20650511 Keywords : atrio-ventricular delay * resynchronization therapy * impedance cardiography * cardiac output Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery

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

    DEFF Research Database (Denmark)

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

    2015-01-01

    reducing EBFR on BP exists and data are conflicting. The aim of this study was to evaluate the effect and the potential mechanism(s) involved by investigating the impact of changes in EBFR on BP, pulse rate (PR) and cardiac output (CO) in HD patients with arteriovenous-fistulas (AV-fistulas). METHODS: We...

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

    International Nuclear Information System (INIS)

    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

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

    DEFF Research Database (Denmark)

    Calbet, José A L; Boushel, Robert

    2015-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  11. A model to calculate cardiac output in hemodialysis patients by thermodilution

    Directory of Open Access Journals (Sweden)

    Alayoud Ahmed

    2012-06-01

    Full Text Available Abstract The Blood Temperature Monitor module (BTM is used to measure recirculation by thermodilution in dialysis. Numerous studies have confirmed its interest in the measuring of the vascular access flow. In this letter we describe a model to calculate cardiac output in dialysis by the BTM.

  12. Non-invasive measurements of cardiac output in atrial fibrillation: Inert gas rebreathing and impedance cardiography

    DEFF Research Database (Denmark)

    Osbak, Philip S; Henriksen, Jens Henrik Sahl; Kofoed, Klaus F;

    2011-01-01

    Abstract Background. Atrial fibrillation (AF) is associated with significant morbidity and mortality. To test the effect of interventions, knowledge of cardiac output (CO) is important. However, the irregular heart rate might cause some methods for determination of CO to have inherent weaknesses...

  13. Investigations concerning the application of the cross-correlation method in cardiac output measurements

    Directory of Open Access Journals (Sweden)

    Gawlikowski Maciej

    2012-05-01

    Full Text Available Abstract Background In spite of numerous non-invasive examinations the “gold clinical standard” of cardiac output measurements is the invasive pulmonary artery catheterization by means of the Swan-Ganz catheter and the application of the thermodilution method to estimate the blood flow. The results obtained by means of thermodilution are sensitive to many physical and biological disturbances. The unreliability of this method amounts to 20-45% and depends on the given variant of the method. Therefore some other method, more accurate and resistant to disturbances, was looked for. This paper presents a new approach to cardiac output measurements, based on cross-correlation signal analysis. The goal of investigations was to verify experimentally the application of the cross-correlation method of cardiac output measurements. Results In 99.2% of the examined cases the extreme of the cross-correlation function was easy to be estimated by numerical algorithms. In 0,8% of the remaining cases (with a plateau region adjacent to the maximum point numerical detection of the extreme was inaccurate. The typical unreliability of the investigated method amounted o 5.1% (9.8% in the worst case. Investigations performed on a physical model revealed that the unreliability of cardiac output measurements by means of the cross-correlation method is 3–5 times better than in the case of thermodilution. Conclusions The performed investigations and theoretical analysis have shown, that the cross-correlation method may be applied in cardiac output measurements. This kind of measurements seems to be more accurate and disturbance-resistant than clinically applied thermodilution.

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

    DEFF Research Database (Denmark)

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

    2015-01-01

    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...

  15. Non-invasive cardiac output trending during exercise recovery on a bathroom-scale-based ballistocardiograph

    International Nuclear Information System (INIS)

    Cardiac ejection of blood into the aorta generates a reaction force on the body that can be measured externally via the ballistocardiogram (BCG). In this study, a commercial bathroom scale was modified to measure the BCGs of nine healthy subjects recovering from treadmill exercise. During the recovery, Doppler echocardiogram signals were obtained simultaneously from the left ventricular outflow tract of the heart. The percentage changes in root-mean-square (RMS) power of the BCG were strongly correlated with the percentage changes in cardiac output measured by Doppler echocardiography (R2 = 0.85, n = 275 data points). The correlation coefficients for individually analyzed data ranged from 0.79 to 0.96. Using Bland–Altman methods for assessing agreement, the mean bias was found to be −0.5% (±24%) in estimating the percentage changes in cardiac output. In contrast to other non-invasive methods for trending cardiac output, the unobtrusive procedure presented here uses inexpensive equipment and could be performed without the aid of a medical professional

  16. Estimating changes in cardiac output using an implanted hemodynamic monitor in heart failure patients

    DEFF Research Database (Denmark)

    Ståhlberg, Marcus; Damgaard, Morten; Ersgård, David;

    2010-01-01

    OBJECTIVES: The aim of this study was to evaluate an algorithm that estimates changes in cardiac output (CO) from right ventricular (RV) pressure waveforms derived from an implantable hemodynamic monitor (IHM) in heart failure patients. DESIGN: Twelve heart failure patients (NYHA II-III, EF 32......%) with an implantable hemodynamic monitor (Chronicle) were included in this study. Changes in cardiac output were provoked by body position change at rest (left lateral supine, horizontal supine, sitting, and standing) and a steady state bicycle exercise at 20 watts. Estimated CO derived from the IHM (CO(IHM......)) was compared to CO measured with inert gas rebreathing (CO(RB)), echocardiography (CO(ECHO)) and impedance cardiography (CO(ICG)). CO(RB) was considered the reference method. RESULTS: The median intra-patient correlation coefficient comparing CO(RB) and CO(IHM) was 0.83 (range: 0.63-0.98). Comparing...

  17. Comparative radionuclide and thermodilution determinations of cardiac output and stroke volume in the baboon (Papio ursinus)

    Energy Technology Data Exchange (ETDEWEB)

    Dormehl, I.C.; Bosman, H.; Hugo, N.; Maree, M.; van Vuuren, C.; van Zandwyk, C.; van Aswegen, A.; Paterson, L.

    1987-01-01

    Thermodilution cardiac output determinations and multigated equilibrium blood-pool scintigraphy were performed in ten healthy chacma baboons (Papio ursinus). The correlation was moderately good between both the radionuclide and thermodilution stroke volume (r = 0.58, SEE = 3 ml; SVth = 0.78SVr + 15.6 ml) as well as the cardiac output (r = 0.72, SEE = 0.2 liter/min; COth = 0.56 Cor + 2.1 liter/min). The attenuation depth dr as determined by radionuclide techniques was found to correlate well with the radiologically determined values dx (r = 0.8, SEE = 0.4 cm; dx = 0.87dr + 0.72 cm) which validated the depth values used in the calculations.

  18. Pulmonary artery pressure responses to increased cardiac output in chickens with raised metabolic rate

    OpenAIRE

    West, John B.; Fu, Zhenxing; Gu, Yusu; Wagner, Harrieth E.; Carr, J. Austin; Peterson, Kirk L.

    2010-01-01

    Previous work has shown remarkable differences in the pressure-flow relations of the pulmonary circulation between birds and mammals. For example several studies suggest that the avian pulmonary blood vessels behave like rigid tubes, very different from the situation in mammalian lung. We therefore speculated that birds would develop high pulmonary artery pressures when the cardiac output was substantially increased during heavy exercise, for example during flight. However because of the tech...

  19. Hereditary Hemorrhagic Telangiectasia Presenting as High Output Cardiac Failure during Pregnancy

    OpenAIRE

    Tareq Goussous; Alex Haynes; Katherine Najarian; Marcos Daccarett; Shukri David

    2009-01-01

    High-output cardiac failure secondary to hepatic involvement is a rare complication of hereditary hemorrhagic telangiectasia (HHT). Here we report a 43-year-old woman who presented at 29 weeks gestation of her second pregnancy with complications of right-sided heart failure and preterm labor. After delivery via cesarean section, the patient was found to have intrahepatic arteriovenous malformations through non-invasive imaging. Subsequently, a family history of vascular malformations and epis...

  20. Clinical validation of a new thermodilution system for the assessment of cardiac output and volumetric parameters

    OpenAIRE

    Kiefer, Nicholas; Hofer, Christoph K; Marx, Gernot; Geisen, Martin; Giraud, Raphaël; Siegenthaler, Nils; Hoeft, Andreas; Bendjelid, Karim; Rex, Steffen

    2012-01-01

    ABSTRACT: INTRODUCTION: Transpulmonary thermodilution is used to measure cardiac output (CO), global end-diastolic volume (GEDV) and extravascular lung water (EVLW). A system has been introduced (VolumeView/EV1000™ system, Edwards Lifesciences, Irvine CA, USA) that employs a novel algorithm for the mathematical analysis of the thermodilution curve. Our aim was to evaluate the agreement of this method with the established PiCCO™ method (Pulsion Medical Systems SE, Munich, Germany, clinicaltria...

  1. Aspects of the continuous clinical measurement of arterial blood pressure and cardiac output

    International Nuclear Information System (INIS)

    In this paper the authors try to classify circulatory measurements as to certain characteristics such as ''activeness'', ''invasivenesss'', etc. Next they turn to defining some fundamental measurements in the blood circulation and focus attention on the continuous measurement of systemic arterial pressure and flow to finally emphasize the inaccuracy of clinical cardiac output methods. The conclusion is that clinical circulatory measurement methods have accuracies at least an order of magnitude worse than common physical methods used in electrical or mechanical engineering. (Auth.)

  2. Diferencia veno-arterial de dióxido de carbono como predictor de gasto cardiaco disminuido en modelo pediátrico experimental Veno-arterial difference of carbondioxide as a predictor of low cardiac output in an experimental pediatric model

    Directory of Open Access Journals (Sweden)

    Franco Díaz

    2012-01-01

    Full Text Available Background: Cardiac output (CO measurement is not a standard of care for critically ill children, but it can be estimated by indirect methods such as veno-arterial pCO2 difference (ΔVACO2. Aim: To determine the correlation between CO and ΔVACO2 and evaluate the usefulness of ΔVACO2 in the diagnosis of low CO in an experimental pediatric model. Materials and Methods: Thirty piglets weighing 4.8 ± 0.35 kg were anesthetized and monitored with transpulmonary thermodilution. Lung injury was induced with tracheal instillation of Tween 20®. Serial measurements of central venous and arterial blood gases, as well as CO, were obtained at baseline, 1, 2 and 4 h after lung injury induction. Low cardiac output (LCO was defined as CO lower than 2.5 Llminlm². Results: There was an inverse correlation between CO and ΔVACO2 (r = -0.36, p < 0.01. ΔVACO2 was 14 ± 8 mmHg in LCO state and 8 ± 6 mmHg when this condition was not present (p < 0.01. Area under the receiver operating characteristic (ROC curves of ΔVACO2 and LCO state was 0.78 (0.68-0.86. The best cut-point was 8.9 mmHg to determine LCO with a sensibility 0.78, specificity 0.7, positive predictive value 0.27 and negative predictive value 0.96. Conclusions: In this model there was an inverse correlation between ΔVACO2 and CO. The best cutoff value to discard LCO was ΔVACO2 of 8.9 mmHg, indicating that under this value the presence of LCO is very unlikely.

  3. The correlation between the first heart sound and cardiac output as measured by using digital esophageal stethoscope under anaesthesia

    OpenAIRE

    Duck Shin, Young; Hoon Yim, Kyoung; Hi Park, Sang; Wook Jeon, Yong; Ho Bae, Jin; Soo Lee, Tae; Hwan Kim, Myoung; Jin Choi, Young

    2014-01-01

    Objective: The use of an esophageal stethoscope is a basic heart sounds monitoring procedure performed in patients under general anesthesia. As the size of the first heart sound can express the left ventricle function, its correlation with cardiac output should be investigated. The aim of this study was to investigate the effects of cardiac output (CO) on the first heart sound (S1) amplitude. Methods : Six male beagles were chosen. The S1 was obtained with the newly developed esophageal steth...

  4. Lack of agreement between bioimpedance and continuous thermodilution measurement of cardiac output in intensive care unit patients

    OpenAIRE

    Barry, Ben N; Mallick, Abhiram; Bodenham, Andrew R; Vucevic, Michael

    1997-01-01

    Background: Bolus thermodilution is the standard bedside method of cardiac output measurement in the intensive care unit (ICU). The Baxter Vigilance monitor uses a modified thermodilution pulmonary artery catheter with a thermal filament to give a continuous read-out of cardiac output. This has been shown to correlate very well with both the 'gold standard' dye dilution method and the bolus thermodilution method. Bioimpedance cardiography using the Bomed NCCOM 3 offers a noninvasive means of ...

  5. A prospective study to evaluate the accuracy of pulse power analysis to monitor cardiac output in critically ill patients

    OpenAIRE

    Grounds R Michael; Fawcett Jayne; Cecconi Maurizio; Rhodes Andrew

    2008-01-01

    Abstract Background Intermittent measurement of cardiac output may be performed using a lithium dilution technique (LiDCO). This can then be used to calibrate a pulse power algorithm of the arterial waveform which provides a continuous estimate of this variable. The purpose of this study was to examine the duration of accuracy of the pulse power algorithm in critically ill patients with respect to time when compared to measurements of cardiac output by an independent technique. Methods Pulse ...

  6. Determination of cardiac output, tissue blood flow, volume and lipid content in Sprague-Dawley rats

    International Nuclear Information System (INIS)

    One critical aspect of physiologically-based pharmacokinetic (PBPK) model development is the choice of values for organ blood flows, cardiac output and tissue volumes for input into models. These values vary depending upon the strain, size, age, and sex of animal for which a PBPK model is being developed. Tissue blood flows, cardiac output, tissue volume, and lipid content were determined in male S-D rats, (350-375 g, N=8). A radiolabel microsphere method utilizing Scandium (46Sc), Tin (113Sn),and Gadolinium (153Gd) was used to determine blood flow. Each rat received 3 radiolabeled injections. After the third injection, animals were sacrificed, and radioactivity in each tissue was determined in a 3-channel gamma counter. Tissues sampled include brain, heart, kidneys, liver, lungs, spleen, pancreas, adrenals, stomach, intestines, colon, testis, bone and skeletal muscle. Cardiac output was 142 ml/min. Blood flow values for eliminating organs were 0.49 (liver), 16.52 (kidney), and 1.77 (lung) ml/min/g tissue. Tissues which had significantly increased blood flow during the dark cycle included femur, abdonimal fat, triceps brachii and abdominal muscles, stomach, spleen and lung. Dissectable fat, organ volume, and organ lipid content were determined in a separate group of rats (N= 8). Volume and lipid content were determined for the same tissues as blood flow. Body fat was 7.35% of bw and extractable lipid content of eliminating organs was 42.3 (liver), 43.4 (kidney), and 35.9 (lung) mg/g tissue. Precise measurements should improve the accuracy of PBPK model predictions, and therfore help in reducing uncertainites in risk assessment of volatile organics and other pollutnats

  7. Continuous versus bolus cardiac output monitoring during or thotopic liver transplantation

    Institute of Scientific and Technical Information of China (English)

    Fang-Ping Bao; Jian Wu

    2008-01-01

    BACKGROUND: Cardiac output monitoring is important for critical patients. This study aimed to determine the delayed response of continuous cardiac output (CCO) thermodilution measurement, whether CCO and bolus cardiac output (BCO) thermodilution agree sufifciently to be used interchangeably, and whether CCO monitoring is reliable for patients undergoing liver transplantation. METHODS:Thirteen patients undergoing liver transplan-tation without veno-venous bypass were studied (37-66 years old, weight 46-75 kg). Continuous and bolus thermodilution measurements were performed at predeifned time points using an "Opti-Q" SvO2/CCO monitor (Abbott Laboratories, North Chicago, IL, USA). Bias and 95% limits of agreement were calculated according to Bland and Altman analysis. The limits of agreement by which two methods are judged to be interchangeable were deifned in advance as ±(13%× BCOmean) L/min. The repeatability and relative error of CCO, and the differences between CCO and the mean of the two measurements were calculated. RESULTS:Cardiac output measurements yielded 196 data pairs with ranges of 1.9 to 17.9 L/min for CCO and 2.1 to 18.3 L/min for BCO. The response time of CCO was delayed in the early phases after caval clamping and after reperfusion. At most of the measurement points, bias and 95%limits of agreement were-0.18±1.91 L/min. 95%limits of agreement did not fall within the predetermined limits of agreement of ±1.14 L/min. The repeatability coefifcient of CCO was 0.36 L/min and the relative error was 4.6±4.7%. The mean difference between CCO and the average of the two methods was-0.09 L/min (0.49 L/min). CONCLUSIONS:In patients undergoing liver transplan-tation, the delayed response of CCO limits its application during the early phases after caval clamping and after reperfusion of the graft. The two methods are not interchangeable even in hemodynamic stability. Continuous thermodilution monitoring, however, is reliable or acceptable for clinical purposes.

  8. Changes in Heart Rate in Patients with a Pacemaker do not Affect Cardiac Output

    Czech Academy of Sciences Publication Activity Database

    Vondra, Vlastimil; Soukup, L.; Jurák, Pavel; Halámek, Josef; Viščor, Ivo; Lipoldová, J.; Leinveber, Pavel

    Piscataway : IEEE, 2012, s. 511. ISBN 978-1-4244-4119-8. [EMBC 2012. Annual International Conference of the IEEE Engineering in Medicine and Biology Society /34./. San Diego (US), 28.08.2012-01.09.2012] R&D Projects: GA MŠk ME09050; GA MŠk ED0017/01/01; GA ČR GAP102/12/2034 Institutional support: RVO:68081731 Keywords : Pacemaker * Changes in Heart Rate * Cardiac Output Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery

  9. Hereditary Hemorrhagic Telangiectasia Presenting as High Output Cardiac Failure during Pregnancy

    Directory of Open Access Journals (Sweden)

    Tareq Goussous

    2009-01-01

    Full Text Available High-output cardiac failure secondary to hepatic involvement is a rare complication of hereditary hemorrhagic telangiectasia (HHT. Here we report a 43-year-old woman who presented at 29 weeks gestation of her second pregnancy with complications of right-sided heart failure and preterm labor. After delivery via cesarean section, the patient was found to have intrahepatic arteriovenous malformations through non-invasive imaging. Subsequently, a family history of vascular malformations and epistaxis was elucidated and a diagnosis of HHT was made. This case is presented, along with a review of the literature and discussion of hepatic involvement in HHT with particular focus on the pregnant patient.

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

    Directory of Open Access Journals (Sweden)

    Leng Xiaoyan

    2009-11-01

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

  11. Factors influencing the development of low output state in patients with right ventricular infarction

    International Nuclear Information System (INIS)

    Right ventricular infarction is frequently accompanied by a low output state, but the factors influencing the development of this state remain unknown. To elucidate these factors, clinical findings, hemodynamic findings and left ventricular infarct size (Tl-score) calculated from thallium-201 myocardial scintigrams by a circumferential profile method were evaluated in 147 consecutive patients with acute transmural inferior myocardial infarction. They were divided into two groups: 44 patients with right ventricular involvement (RVI group) and 103 patients without right ventricular involvement (IMI group). A low cardiac output state was defined when the cardiac index was less than 2.2 L/min/M2. There was a good correlation between Tl-score and any of peak value of serum creatine phosphokinase (CPKmax), total released CPK (CPKr) and left ventricular ejection fraction (LVEF) (r=o.66, 0.74 and -0.54, respectively), indicating the usefulness of Tl-score as an index of left ventricular damage. Compared to the IMI group, the RVI group showed a higher average of age (p<0.01), lower systemic blood pressure (p<0.01), higher right atrial pressure (p<0.001) and lower cardiac index (p<0.01). Furthermore, t he incidence of a low output state (RVI group:47.7% vs IMI group:14.6%, p<0.001) and mortality (25.0% vs 7.8%, p<0.01) were higher in the RVI group. However, CPKmax, CPKr, LVEF and Tl-score, which were considered to reflect the severity of left ventricular damage, were not different between the two groups. Tl-score was inversely correlated with cardiac index in the RVI group (r=-0.49, p<0.05), and with left ventricular stroke work index in the both groups (RVI group;r=-0.46, p<0.01, IMI group; r=-0.64, p<0.01). (J.P.N.)

  12. Estimation of cardiac output by first-pass transit of radiotracers

    International Nuclear Information System (INIS)

    To evaluate cardiac function with various tracers to be used for radionuclide scintigraphy, we examined the validity of a simplified method to measure cardiac output (CO) by modifying the equation of Stewart-Hamilton in the radionuclide study. After a bolus injection of I-123 or Tc-99m tracer, the total injection dose and count in the pulmonary artery during the first transit of the tracer were measured to calculate the CO Index. The CO Index was obtained from the integral of the first transit of radiotracers in the pulmonary artery divided by the total injected count. CO was estimated from the regression formula which was obtained by comparing the CO Index with CO measured by the Doppler echocardiographic method. There were close correlations between the CO Index and CO measured by Doppler echocardiography both in the study with I-123 (n=13, r=0.85, p0.634 for I-123 and CO=3.18 x (CO Index)0.518 for Tc-99m). CO measured by this method is useful for the assessment of cardiac function with various tracers in routine clinical studies, and this simple method may be utilized for assessment of organ blood flow on the basis of the microsphere model. (author)

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

    Science.gov (United States)

    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

  14. Increasing cardiac output and decreasing oxygenation sequence in pump twins of acardiac twin pregnancies

    International Nuclear Information System (INIS)

    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. (note)

  15. Increasing cardiac output and decreasing oxygenation sequence in pump twins of acardiac twin pregnancies

    Energy Technology Data Exchange (ETDEWEB)

    Gemert, Martin J C van [Laser Center and Department of Obstetrics and Gynecology, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam (Netherlands); Umur, Asli [Laser Center and Department of Obstetrics and Gynecology, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam (Netherlands); Wijngaard, Jeroen P H M van den [Laser Center and Department of Obstetrics and Gynecology, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam (Netherlands); VanBavel, Ed [Department of Medical Physics, Academic Medical Center, University of Amsterdam, Amsterdam (Netherlands); Vandenbussche, Frank P H A [Department of Obstetrics, Leiden University Medical Center, Leiden (Netherlands); Nikkels, Peter G J [Department of Pathology, University Medical Center, Utrecht (Netherlands)

    2005-02-07

    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. (note)

  16. Implementation strategy for soft switching PFC with low output voltage

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    This paper proposes a novel implementation strategy for soft switching PFC whose circuit is simple and can achieve low voltage output directly. The main circuit adopts current mode full-bridge converter and all the power switches can realize ZCS or ZVS in the way of phase-shifted control, using the leakage inductance of the transformer, the junction capacitor of the switches and the stored energy of the output capacitor. The problems such as the function of phase-shifted link in control circuit, the implementation conditions of soft switching and bias restrained are analyzed. The adoption of constant frequency PWM control makes the design of the input and output filter link and the high frequency transformer simple. The transformation ratio regulation so as to achieve low voltage output and electrical insulation can be realized by using high frequency transformer.

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

    Science.gov (United States)

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

    2011-01-01

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

  18. Reliability of first-pass radionuclide determination of cardiac output in the upright position at rest and during exercise

    Energy Technology Data Exchange (ETDEWEB)

    Kelbaek, H.; Gjoerup, T.; Hvid-Jacobsen, K.; Skagen, K.; Munck, O. (Herlev Hospital (Denmark). Dept. of Clinical Physiology and Nuclear Medicine); Godtfredsen, J. (Herlev Hospital (Denmark). Dept. of Cardiology); Heslet, L. (Herlev Hospital (Denmark). Dept. of Anesthesiology); Tjur, T.; Jensen, A.M. (Copenhagen Univ. (Denmark). Inst. for Mathematical Statistics)

    1992-11-01

    The reliability of non-invasive determination of cardiac output using first-pass radionuclide cardiography at rest and during exercise in the upright position was evaluated in 20 patients with coronary artery disease. Cardiac output values ranged from 2.97 to 5.99 l/min at rest and from 5.08 to 10.82 l/min during exercise. Cardiac output results obtained by the radionuclide method were compared with those derived from the thermodilution technique performed simultaneously. The mean difference between the two techniques was 0.02/l min at rest and -0.34 l/min during exercise; the limits of agreement (mean {+-}1.96 SD) were -1.29 to 1.33 l/min and -1.97 to 1.29 l/min, respectively, indicating an acceptable level of agreement. A high reproducibility of the radionuclide technique was found, with a mean difference between determinations by two observers of 0.03 l/min at rest and 0.21 l/min during exercise, the corresponding limits of agreement being -0.75 to 0.81 l/min and -0.79 to 1.21 l/min, respectively. With the aid of a variance component analysis of two determinations by each of four observers, 95% confidence intervals of {+-}10% at rest at {+-}12% during exercise were computed for the radionuclide cardiac output measurements. The observer variation was most pronounced for the part of the cardiac output determination related to measurement of left ventricular equilibrium activity during exercise. First-pass radionuclide cardiography is a reliable method for determination of cardiac output in cardiac patients at rest and during exercise in the upright position. (orig.).

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

    Science.gov (United States)

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

    2015-06-01

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

  20. Evaluation of a new arterial pressure-based cardiac output device requiring no external calibration

    Directory of Open Access Journals (Sweden)

    Amann Matthias

    2007-11-01

    Full Text Available Abstract Background Several techniques have been discussed as alternatives to the intermittent bolus thermodilution cardiac output (COPAC measurement by the pulmonary artery catheter (PAC. However, these techniques usually require a central venous line, an additional catheter, or a special calibration procedure. A new arterial pressure-based cardiac output (COAP device (FloTrac™, Vigileo™; Edwards Lifesciences, Irvine, CA, USA only requires access to the radial or femoral artery using a standard arterial catheter and does not need an external calibration. We validated this technique in critically ill patients in the intensive care unit (ICU using COPAC as the method of reference. Methods We studied 20 critically ill patients, aged 16 to 74 years (mean, 55.5 ± 18.8 years, who required both arterial and pulmonary artery pressure monitoring. COPAC measurements were performed at least every 4 hours and calculated as the average of 3 measurements, while COAP values were taken immediately at the end of bolus determinations. Accuracy of measurements was assessed by calculating the bias and limits of agreement using the method described by Bland and Altman. Results A total of 164 coupled measurements were obtained. Absolute values of COPAC ranged from 2.80 to 10.80 l/min (mean 5.93 ± 1.55 l/min. The bias and limits of agreement between COPAC and COAP for unequal numbers of replicates was 0.02 ± 2.92 l/min. The percentage error between COPAC and COAP was 49.3%. The bias between percentage changes in COPAC (ΔCOPAC and percentage changes in COAP (ΔCOAP for consecutive measurements was -0.70% ± 32.28%. COPAC and COAP showed a Pearson correlation coefficient of 0.58 (p PAC and ΔCOAP was 0.46 (p Conclusion Although the COAP algorithm shows a minimal bias with COPAC over a wide range of values in an inhomogeneous group of critically ill patients, the scattering of the data remains relative wide. Therefore, the used algorithm (V 1.03 failed to

  1. Cardiac Output and Stroke Volume at Anaerobic Threshold During Walking Exercise in Healthy Aged Subjects

    OpenAIRE

    Haga, Shukoh; Esaki, Kazuki; Toshinai, Kouji; Kinugasa, Takeshi; Takemasa, Toru; Ueya, Etsuo; Hamaoka, Takaumi; Katsumura, Toshihito; Kizaki, Takako; Ohno, Hideki

    2003-01-01

    HAGA, S., ESAKI, K., TOSHINAI, K., KINUGASA, T., TAKEMASA, T., UEYA, E., HAMAOKA, T., KATSUMURA, T., KIZAKI, t. and OHNO, H., Cardiac Output and Stroke Volume at Anaerobic Threshold During Walking Exercise in Healthy Aged Subjects. Abv. Exerc. Sports Physiol., Vol.9, No.1 pp.37-43, 2003. There have been few previous studies of cardiac outout for cardiovascular function at anaerobic threshold (AT) during walking exercise in healthy elderly subjects. The present study was performed to investiga...

  2. Is pulmonary gas exchange during exercise in hypoxia impaired with the increase of cardiac output?

    DEFF Research Database (Denmark)

    Calbet, J.A.; Robach, P.; Lundby, C.;

    2008-01-01

    diffusion with increases in exercise intensity. We have consistently observed that during steady-state, submaximal (100-120 W) exercise on the cycle ergometer in hypoxia the lung can accommodate an increase in cardiac output of approximately 2 L x min(-1) without any significant effect on pulmonary gas......During exercise in humans, the alveolar-arterial O(2) tension difference ((A-a)DO(2)) increases with exercise intensity and is an important factor determining the absolute level of oxygen binding to hemoglobin and therefore the level of systemic oxygen transport. During exercise in hypoxia, the (A......-a)DO(2) is accentuated. Using the multiple inert gas elimination technique it has been shown that during exercise in acute hypoxia the contribution of ventilation-perfusion inequality to (A-a)DO(2) is rather small and in the absence of pulmonary edema intrapulmonary shunts can be ruled out. This implies...

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

    Energy Technology Data Exchange (ETDEWEB)

    Williams, L.R. [Indiana Univ., South Bend, IN (United States). Division of Liberal Arts and Sciences

    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.

  4. Sildenafil improves cardiac output and exercise performance during acute hypoxia, but not normoxia.

    Science.gov (United States)

    Hsu, Andrew R; Barnholt, Kimberly E; Grundmann, Nicolas K; Lin, Joseph H; McCallum, Stewart W; Friedlander, Anne L

    2006-06-01

    Sildenafil causes pulmonary vasodilation, thus potentially reducing impairments of hypoxia-induced pulmonary hypertension on exercise performance at altitude. The purpose of this study was to determine the effects of sildenafil during normoxic and hypoxic exercise. We hypothesized that 1) sildenafil would have no significant effects on normoxic exercise, and 2) sildenafil would improve cardiac output, arterial oxygen saturation (SaO2), and performance during hypoxic exercise. Ten trained men performed one practice and three experimental trials at sea level (SL) and simulated high altitude (HA) of 3,874 m. Each cycling test consisted of a set-work-rate portion (55% work capacity: 1 h SL, 30 min HA) followed immediately by a time trial (10 km SL, 6 km HA). Double-blinded capsules (placebo, 50, or 100 mg) were taken 1 h before exercise in a randomly counterbalanced order. For HA, subjects also began breathing hypoxic gas (12.8% oxygen) 1 h before exercise. At SL, sildenafil had no effects on any cardiovascular or performance measures. At HA, sildenafil increased stroke volume (measured by impedance cardiography), cardiac output, and SaO2 during set-work-rate exercise. Sildenafil lowered 6-km time-trial time by 15% (P<0.05). SaO2 was also higher during the time trial (P<0.05) in response to sildenafil, despite higher work rates. Post hoc analyses revealed two subject groups, sildenafil responders and nonresponders, who improved time-trial performance by 39% (P<0.05) and 1.0%, respectively. No dose-response effects were observed. During cycling exercise in acute hypoxia, sildenafil can greatly improve cardiovascular function, SaO2, and performance for certain individuals. PMID:16455814

  5. Quantum dot amplifiers with high output power and low noise

    DEFF Research Database (Denmark)

    Berg, Tommy Winther; Mørk, Jesper

    2003-01-01

    Quantum dot semiconductor optical amplifiers have been theoretically investigated and are predicted to achieve high saturated output power, large gain, and low noise figure. We discuss the device dynamics and, in particular, show that the presence of highly inverted barrier states does not limit...

  6. A prospective study to evaluate the accuracy of pulse power analysis to monitor cardiac output in critically ill patients

    Directory of Open Access Journals (Sweden)

    Grounds R Michael

    2008-02-01

    Full Text Available Abstract Background Intermittent measurement of cardiac output may be performed using a lithium dilution technique (LiDCO. This can then be used to calibrate a pulse power algorithm of the arterial waveform which provides a continuous estimate of this variable. The purpose of this study was to examine the duration of accuracy of the pulse power algorithm in critically ill patients with respect to time when compared to measurements of cardiac output by an independent technique. Methods Pulse power analysis was performed on critically ill patients using a proprietary commercial monitor (PulseCO. All measurements were made using an in-dwelling radial artery line and according to manufacturers instructions. Intermittent measurements of cardiac output were made with LiDCO in order to validate the pulse power measurements. These were made at baseline and then following 1, 2, 4 and 8 hours. The LiDCO measurement was considered the reference for comparison in this study. The two methods of measuring cardiac output were then compared by linear regression and a Bland Altman analysis. An error rate for the limits of agreement (LOA between the two techniques of less than 30% was defined as being acceptable for this study. Results 14 critically ill medical and surgical patients were enrolled over a three month period. At baseline patients showed a wide range of cardiac output (median 7.5 L/min, IQR 5.1 -9.0 L/min. The bias and limits of agreement between the two techniques was deemed acceptable for the first four hours of the study with percentage errors being 29%, 22%, and 285 respectively. The percentage error at eight hours following calibration increased to 36%. The ability of the PulseCo to detect changes in cardiac output was assessed with a similar analysis. The PulseCO tracked the changes in cardiac output with adequate accuracy for the first four hours with percentage errors being 20%, 24% and 25%. However at eight hours the error had increased to

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

    Science.gov (United States)

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

    2009-04-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-04-07

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

  9. Cardiac output response to changes of the atrioventricular delay in different body positions and during exercise in patients receiving cardiac resynchronization therapy

    DEFF Research Database (Denmark)

    Ståhlberg, Marcus; Damgaard, Morten; Norsk, Peter; Gabrielsen, Anders; Sahlén, Anders; Linde, Cecilia; Braunschweig, Frieder

    2009-01-01

    prolonged by 40 ms in 27 CRT patients and 9 controls without heart failure. Cardiac output (CO) was measured by inert gas rebreathing (Innocor) as the average over different body positions (left-lateral, supine, sitting, standing, and exercise). In eight CRT patients with an implantable haemodynamic monitor...

  10. Measurement of cardiac output during exercise in healthy, trained humans using lithium dilution and pulse contour analysis

    International Nuclear Information System (INIS)

    The aim of this study was to evaluate the use of pulse contour analysis calibrated with lithium dilution in a single device (LiDCO™) for measurement of cardiac output (.Q) during exercise in healthy volunteers. We sought to; (a) compare pulse contour analysis (PulseCO) and lithium indicator dilution (LiDCO) for the measurement of .Q during exercise, and (b) assess the requirement for recalibration of PulseCO with LiDCO during exercise. Ten trained males performed multi-stage cycling exercise at intensities below and above ventilatory threshold before constant load maximal exercise to exhaustion. Uncalibrated PulseCO .Q (.Qraw) was compared to that calibrated with lithium dilution at baseline (.Qbaseline), during submaximal exercise below (.Qlow) and above (.Qhigh) ventilatory threshold, and at each exercise stage individually (.Qexercise). There was a significant difference between .Qbaseline and all other calibration methods during exercise, but not at rest. No significant differences were observed between other methods. Closest agreement with .Qexercise was observed for .Qhigh (bias ± limits of agreement: 4.8 ± 30.0%). The difference between .Qexercise and both .Qlow and .Qraw was characterized by low bias (4–7%) and wide limits of agreement (>±40%). Calibration of pulse contour analysis with lithium dilution prior to exercise leads to a systematic overestimation of exercising cardiac output. A single calibration performed during exercise above the ventilatory threshold provided acceptable limits of agreement with an approach incorporating multiple calibrations throughout exercise. Pulse contour analysis may be used for .Q measurement during exercise providing the system is calibrated during exercise. (paper)

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

    LENUS (Irish Health Repository)

    Healy, David G

    2012-02-03

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

  12. Effect of heat stress on cardiac output and systemic vascular conductance during simulated hemorrhage to presyncope in young men

    DEFF Research Database (Denmark)

    Ganio, Matthew S; Overgaard, Morten; Seifert, Thomas; Secher, Niels H; Johansson, Pär I; Meyer, Martin; Crandall, Craig G

    2012-01-01

    During moderate actual or simulated hemorrhage, as cardiac output decreases, reductions in systemic vascular conductance (SVC) maintain mean arterial pressure (MAP). Heat stress, however, compromises the control of MAP during simulated hemorrhage, and it remains unknown whether this response is due...

  13. Estimation of cardiac output by first-pass data with technetium-99m-labeled myocardial perfusion imaging agent

    International Nuclear Information System (INIS)

    Technetium-99m-tetrofosmin, a myocardial perfusion imaging agent was used for estimation of cardiac output by means of first-pass radionuclide angiography performed in the anterior projection. Region of interests (ROIs) were assigned over right ventricle, left ventricle and whole chest, and time activity curves (TACs) were obtained. Cardiac output indices (COIs) were calculated by the following equation; COI=p3/2·Qc/∫0tA(s)ds, where p=number of pixels of the ventricular ROI, Qc=the peak count rate of the TAC obtained from the whole chest's ROI and ∫0tA(s)ds=the area under ventricular TAC. The COI(y) determined by ROI over the left ventricle yield the best correlation with the cardiac output by conventional radionuclide method (x) (y=0.0381x+6.22, r=0.828, n=48, p<0.001). In conclusion, cardiac output can be easily measured with first pass data using myocardial perfusion imaging agent. (author)

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

    Science.gov (United States)

    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.

  15. Chaotic Microcavity Laser with Low threshold and Unidirectional Output

    CERN Document Server

    Song, Q H; Liu, B Y; Ho, S T; Fang, W; Solomon, G s

    2015-01-01

    Here we report lasing action in lima\\c{c}on-shaped GaAs microdisks with quantum dots (QDs) embedded. Although the intracavity ray dynamics is predominantly chaotic, high-$Q$ modes are concentrated in the region $\\chi > \\chi_c$ as a result of wave localization. Strong optical confinement by total internal reflection leads to very low lasing threshold. Our measurements show that all the lasing modes have output in the same direction, regardless of their wavelengths and intracavity mode structures. This universal emission direction is determined by directed phase space flow of optical rays in the open chaotic cavity. The divergence angle of output beam is less than 40 degree. The unidirectionality proves to be robust against small deviations of the real cavity shape and size from the designed values.

  16. A novel continuous cardiac output monitor based on pulse wave transit time.

    Science.gov (United States)

    Sugo, Yoshihiro; Ukawa, Teiji; Takeda, Sunao; Ishihara, Hironori; Kazama, Tomiei; Takeda, Junzo

    2010-01-01

    Monitoring cardiac output (CO) is important for the management of patient circulation in an operation room (OR) or intensive care unit (ICU). We assumed that the change in pulse wave transit time (PWTT) obtained from an electrocardiogram (ECG) and a pulse oximeter wave is correlated with the change in stroke volume (SV), from which CO is derived. The present study reports the verification of this hypothesis using a hemodynamic analysis theory and animal study. PWTT consists of a pre-ejection period (PEP), the pulse transit time through an elasticity artery (T(1)), and the pulse transit time through peripheral resistance arteries (T(2)). We assumed a consistent negative correlation between PWTT and SV under all conditions of varying circulatory dynamics. The equation for calculating SV from PWTT was derived based on the following procedures. 1. Approximating SV using a linear equation of PWTT. 2. The slope and y-intercept of the above equation were determined under consideration of vessel compliance (SV was divided by Pulse Pressure (PP)), animal type, and the inherent relationship between PP and PWTT. Animal study was performed to verify the above-mentioned assumption. The correlation coefficient of PWTT and SV became r = -0.710 (p 〈 0.001), and a good correlation was admitted. It has been confirmed that accurate continuous CO and SV measurement is only possible by monitoring regular clinical parameters (ECG, SpO2, and NIBP). PMID:21095971

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

    Science.gov (United States)

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

    2016-01-01

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

  18. Thermal dilution measurement of cardiac output in dogs using an analog computer.

    Science.gov (United States)

    Hendriks, F F; Schipperheyn, J J; Quanjer, P H

    1978-01-01

    Thermal dilution cardiac output determinations in dogs were compared to simultaneously performed Fick oxygen measurements. The purpose of this study was to validate in dog experiments a method for thermal dilution measurement which employs a double-thermistor catheter combined with an automatic computer as described by Olsson et al. Dilution and injectate temperature are entered directly into the calculation. The method does not employ logarithmic extrapolation, integration of the dilution signal being terminated when a preset cut-off level is reached. Errors due to recirculation, thermal capacitance of the right heart and heat exchange with the catheter's dead space require the use of an empirically derived correction factor, which in dogs was found to be significantly different from the factor used for human thermal dilution curves. With the appropriate cut-off level and correction factor a good agreement was found between the results of the thermal dilution and the Fick method. The regression equation for 47 experiments was found to be COtd = 0.95 COFick + 0.08; the correlation coefficient was 0.94. PMID:728031

  19. Cardiac Output Measurements in Septic Patients: Comparing the Accuracy of USCOM to PiCCO

    Directory of Open Access Journals (Sweden)

    Sophia Horster

    2012-01-01

    Full Text Available USCOM is an ultrasound-based method which has been accepted for noninvasive hemodynamic monitoring in various clinical conditions (USCOM, Ultrasonic cardiac output monitoring. The present study aimed at comparing the accuracy of the USCOM device with that of the thermodilution technique in patients with septicemia. We conducted a prospective observational study in a medical but noncardiological ICU of a university hospital. Septic adult patients (median age 55 years, median SAPS-II-Score 43 points on mechanical ventilation and catecholamine support were monitored with USCOM and PiCCO (=70. Seventy paired left-sided CO measurements (transaortic access = COUS-A were obtained. The mean COUS-A were 6.55 l/min (±2.19 versus COPiCCO 6.5 l/min (±2.18. The correlation coefficient was =0.89. Comparison by Bland-Altman analysis revealed a bias of −0.36 l/min (±0.99 l/min leading to a mean percentage error of 29%. USCOM is a feasible and rapid method to evaluate CO in septic patients. USCOM does reliably represent CO values as compared to the reference technique based on thermodilution (PiCCO. It seems to be appropriate in situations where CO measurements are most pertinent to patient management.

  20. Non-invasive measurement of cardiac output by Finometer in patients with cirrhosis

    DEFF Research Database (Denmark)

    Kaltoft, Nicolai Stefan; Hobolth, L; Møller, S

    2010-01-01

    The Finometer measures haemodynamic parameters including cardiac output (CO) using non-invasive volume-clamp techniques. The aim of this study was to determine the accuracy of the Finometer in hyperdynamic cirrhotic patients using an invasive indicator dilution technique as control. CO was measured......(I) was 6.1 +/- 1.6 [3.9;9.7] l min(-1) (mean +/- SD [range]) compared to mean CO(F) of 7.2 +/- 2.3 [3.1;11.9] l min(-1). There was a mean difference between CO(F) and CO(I) of 1.0 +/- 1.8 [-2.1;4.0] l min(-1) and 95% confidence interval of [0.2;1.8], P<0.001. In patients with measurements before and...... after beta-blockade, mean DeltaCO(I) was 1.6 +/- 1.4 [-0.1;3.3] l min(-1) compared to mean DeltaCO(F) of 1.9 +/- 1.3 [0.4;3.8] l min(-1). Mean difference between DeltaCO(F) and DeltaCO(I) was 0.3 +/- 0.3 [-0.2;0.7] l min(-1) with a 95% confidence interval of [-0.1;0.6], P = 0.11. Compared with invasive...

  1. Effects of sedation with low-dosage dexmedetomidine on cardiac function in elderly surgical patients

    OpenAIRE

    Yu LANG; Tian-long WANG

    2011-01-01

    Objective To investigate the influence of continuous infusion of low-dose dexmedetomidine(DEX) for sedation on cardiac function index in elderly surgical patients,and assess the impacts on circulation.Methods Sixty elderly surgical patients were randomized into DEX group and control group(30 each).The sex ratio of the patients was 24/36(male/female),and age from 65 to 89 years.After the cannulation of left radial artery,the arterial pressure continuous cardiac output(APCO) monitor(Edwards,USA...

  2. Low-dose exposure of silica nanoparticles induces cardiac dysfunction via neutrophil-mediated inflammation and cardiac contraction in zebrafish embryos.

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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

  4. The effect of halothane on the distribution of cardiac output and organ blood flows in the hemorrhagic, hypotensive dog

    International Nuclear Information System (INIS)

    Halothane was given to dogs which had been bled to an arterial mean blood pressure of 60 mmHg, and the circulatory effects were studied with the aid of the radioactive microsphere technique. The cardiac output and coronary blood flow were well maintained, whereas the arterial mean blood pressure was slightly, and the stroke volume markedly increased, indicating an improved heart function. The blood flows to the brain, lungs, liver and kidneys were well preserved throughout the anesthesia. The effect of retransfusing the withdrawn blood was also studied, and it resulted in an increased cardiac output, arterial mean blood pressure and increased blood flows to the heart, lungs, spleen, bowel and liver. (author)

  5. Effectiveness of Human Atrial Natriuretic Peptide Supplementation in Pulmonary Edema Patients Using the Pulse Contour Cardiac Output System

    OpenAIRE

    Sakamoto, Yuichiro; Mashiko, Kunihiro; Saito, Nobuyuki; Matsumoto, Hisashi; Hara, Yoshiaki; Kutsukata, Noriyoshi; Yokota, Hiroyuki

    2010-01-01

    Purpose Atrial natriuretic peptide (ANP) has a variety of pharmacologic effects, including natriuresis, diuresis, vasodilatation, and suppression of the renin-angiotensin system. A recent study showed that ANP infusion improved hypoxemia and pulmonary hypertension in a lung injury model. On the other hand, the pulse contour cardiac output (PiCCO™) system (Pulsion Medical Systems, Munich, Germany) allows monitoring of the intravascular volume status and may be used to guide volume therapy in s...

  6. Performance of a new pulse contour method for continuous cardiac output monitoring: validation in critically ill patients

    OpenAIRE

    Bendjelid, Karim; Marx, G.; Kiefer, N.; Simon, T P; Geisen, M; Hoeft, A.; Siegenthaler, Nils; Hofer, C K

    2013-01-01

    BACKGROUND: /st>A new calibrated pulse wave analysis method (VolumeView™/EV1000™, Edwards Lifesciences, Irvine, CA, USA) has been developed to continuously monitor cardiac output (CO). The aim of this study was to compare the performance of the VolumeView method, and of the PiCCO2™ pulse contour method (Pulsion Medical Systems, Munich, Germany), with reference transpulmonary thermodilution (TPTD) CO measurements. METHODS: /st>This was a prospective, multicentre observational study performed i...

  7. The use of a cardiac output monitor to guide the initial fluid resuscitation in a patient with burns

    OpenAIRE

    Reid, Robert Darren; Jayamaha, John

    2007-01-01

    A case of initial resuscitation of a patient with severe burns is described. Such patients can have hypotension and reduced organ perfusion for a number of reasons, and can remain in the emergency department for many hours while awaiting transfer to specialist centres. The case provides a comparison between resuscitation using traditional burns formulae and a relatively new and simple‐to‐use cardiac output (CO) monitor—the Vigileo monitor (Edwards Lifesciences, Irvine, California, USA). The c...

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

    Directory of Open Access Journals (Sweden)

    Frédéric Lador

    Full Text Available 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.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.Baseline COMF and COTD were 6.18 ± 1.95 and 5.46 ± 1.95 L·min-1, respectively. Accuracy and precision were 0.72 and 1.04 L·min-1, respectively. Limits of agreement (LoA ranged from -1.32 to 2.76 L·min-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 L·min-1 and precision 0.61 L·min-1. LoA ranged from -1.23 to 1.17 L·min-1 and PE was ±19.8%.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.

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

    International Nuclear Information System (INIS)

    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.

  10. Effects of sedation with low-dosage dexmedetomidine on cardiac function in elderly surgical patients

    Directory of Open Access Journals (Sweden)

    Yu LANG

    2011-09-01

    Full Text Available Objective To investigate the influence of continuous infusion of low-dose dexmedetomidine(DEX for sedation on cardiac function index in elderly surgical patients,and assess the impacts on circulation.Methods Sixty elderly surgical patients were randomized into DEX group and control group(30 each.The sex ratio of the patients was 24/36(male/female,and age from 65 to 89 years.After the cannulation of left radial artery,the arterial pressure continuous cardiac output(APCO monitor(Edwards,USA was connected,and the cardiac function index was continuously monitored,including cardiac output index(CI,stroke volume index(SVI,heart rate(HR and mean arterial pressure(MAP.The patients in DEX group were infused with DEX at 0.4μg(kg·h for 10min following intrathecal anesthesia,then the infusion rate was adjusted from 0.2 to 0.4μg(kg·h to keep the bispectral index values(BIS maintained between 75 and 85.Normal saline was administered with an equal volume in control group.The MAP,HR,respiration rate(RR,pulse oxygen saturation(SpO2,the partial pressure of end-tidal carbon dioxide(PETCO2 and BIS were recorded immediately at the DEX infusion(T0,and 10min(T1,20min(T2,30min(T3,60min(T4 after DEX infusion,and the end of surgery(T5.All cardiac function data were statistically analyzed,and P 0.05.Conclusion The sedation with continuous infusion of small-dosage DEX during intrathecal anesthesia in elderly surgical patients may have little impact on cardiac function index,but the conclusion remains to be verified with large sample and multicenter research.

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

    Science.gov (United States)

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

    2015-12-15

    Air pollution has recently been associated with the development of acute decompensated heart failure, but the underlying biological mechanisms remain unclear. A pulmonary vasoconstrictor effect of air pollution, combined with its systemic effects, may precipitate decompensated heart failure. The aim of the present study was to investigate the effects of acute exposure to diesel exhaust (DE) on pulmonary vascular resistance (PVR) under resting and stress conditions but also to determine whether air pollution may potentiate acquired pulmonary hypertension. Eighteen healthy male volunteers were exposed to ambient air (AA) or dilute DE with a particulate matter of effects of DE on PVR, on the coefficient of distensibilty of pulmonary vessels (α), and on right and left ventricular function were evaluated at rest (n = 18), during dobutamine stress echocardiography (n = 10), and during exercise stress echocardiography performed in hypoxia (n = 8). Serum endothelin-1 and fractional exhaled nitric oxide were also measured. At rest, exposure to DE did not affect PVR. During dobutamine stress, the slope of the mean pulmonary artery pressure-cardiac output relationship increased from 2.8 ± 0.5 mmHg · min · l (-1) in AA to 3.9 ± 0.5 mmHg · min · l (-1) in DE (P 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

  12. Pulsatile flow simulator for comparison of cardiac output measurements by electromagnetic flow meter and thermodilution.

    Science.gov (United States)

    Jebson, P J; Karkow, W S

    1986-01-01

    This study examined a pulsatile flow simulator for the purpose of evaluating two measurement devices, an extracorporeal flow probe with an electromagnetic flow meter and several thermodilution catheters. We measured the performance of these devices in a range of low to high flows. Using either saline or blood as a perfusate, we obtained different results with these fluids (p less than 0.001). Each catheter behaved in a linear manner, although variation occurred among the catheters with both saline (minimum slope 1.090, maximum slope 1.190) and blood (minimum slope 1.107, maximum slope 1.154). An increase in rate and stroke volumes of the simulator did not demonstrate an identifiable trend in error. The thermodilution catheters were most accurate at 5.0 L/min irrespective of rate, stroke volume, or perfusate used. In contrast, the electromagnetic flow meter accurately represented flows across the wide range of outputs examined (2.4 to 10.7 L/min). (Slope with saline 1.091, slope with blood 1.080) Throughout the range of flow, the flow meter gave a calibration line 5% higher with blood than with saline. The results indicate that accurate measurement of pulsatile blood flow can be achieved in vitro with an electromagnetic flow meter using saline as a perfusate, provided a correction factor is determined and applied to convert values for saline to accurate values for blood. PMID:2940345

  13. Exercise-related change in airway blood flow in humans: Relationship to changes in cardiac output and ventilation

    OpenAIRE

    Morris, Norman R; Ceridon, Maile L.; Beck, Kenneth C.; Strom, Nicholas A.; Schneider, Donald A; Mendes, Eliana S; Wanner, Adam; Johnson, Bruce D.

    2008-01-01

    This study examined the relationship between airway blood flow (Q̇aw), ventilation (V̇E) and cardiac output (Q̇tot) during exercise in healthy humans (n = 12, mean age 34 ± 11 yr). Q̇aw was estimated from the uptake of the soluble gas dimethyl ether while V̇E and Q̇tot were measured using open circuit spirometry. Measurements were made prior to and during exercise at 34 ± 5W (Load 1) and 68 ± 10 W (Load 2) and following the cessation of exercise (recovery). Q̇aw increased in a stepwise fashio...

  14. Noninvasive cardiac output determination using applanation tonometry-derived radial artery pulse contour analysis in critically ill patients

    DEFF Research Database (Denmark)

    Compton, Friederike; Wittrock, Marc; Schaefer, Juergen-Heiner;

    2008-01-01

    Conventional thermodilution cardiac output (CO) monitoring is limited mainly to intensive care units and operating rooms because it requires the use of invasive techniques. To reduce the potential for complications and to broaden the applicability of hemodynamic monitoring, noninvasive methods for...... were analyzed with bias and precision statistics, a large bias of 2.03 L x min(-1) x m(-2) and a high percentage error of 85% were found between the invasive measurements and applanation tonometry-derived CO estimates, with the noninvasive CO results being significantly lower than the invasive ones (P...

  15. Sarcomere length dependence of power output is increased after PKA treatment in rat cardiac myocytes

    OpenAIRE

    Hanft, Laurin M.; McDonald, Kerry S.

    2009-01-01

    The Frank-Starling relationship of the heart yields increased stroke volume with greater end-diastolic volume, and this relationship is steeper after β-adrenergic stimulation. The underlying basis for the Frank-Starling mechanism involves length-dependent changes in both Ca2+ sensitivity of myofibrillar force and power output. In this study, we tested the hypothesis that PKA-induced phosphorylation of myofibrillar proteins would increase the length dependence of myofibrillar power output, whi...

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

    Science.gov (United States)

    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

  17. Cardiac output measured by the FloTrac/Vigileo system: Does the „plug and play“ principle work?

    Directory of Open Access Journals (Sweden)

    H. Maxeiner

    2010-06-01

    Full Text Available Background: Determination of cardiac output by the classic thermodilution technique is widely accepted to be the gold standard, but it is not without additional risks due to invasive catheterisation. Therefore, we compared it with the less invasive FloTracTM/VigileoTM-system based on an automated pulse contour analysis.Methods: 34 patients who underwent cardiac surgery with extracorporal circulation were included. In each patient, four measurements were performed. A software update split the patients into two groups: 19 of them were measured using software version V1.07, 15 were measured using software version V1.10.Results: Overall, 120 measurements were performed. Software version V1.07 showed a bias of -0.45l•(min•m2-1 and a precision of 0.53l•(min•m2-1. The percentage error was 45%. Software version V1.10 showed a bias of -0.26l•(min•m2-1 and a precision of 0.42l•(min•m2-1, the percentage error was 36% in this case. The differences were statistically significant with respect to the bias but not to the precision.Conclusion: Although software version V1.10 led to an improvement in the concordance with thermodilution technique, the percentage error exceeds the acceptable threshold of 28.28%. Therefore, in the setting of cardiac surgery the FloTracTM/VigileoTM-system cannot replace the thermodilution technique at present.

  18. Comparison between continuous non-invasive estimated cardiac output by pulse wave transit time and thermodilution method

    Directory of Open Access Journals (Sweden)

    Ashish C Sinha

    2014-01-01

    Full Text Available Aims and Objectives: Cardiac output (CO measurement is essential for many therapeutic decisions in anesthesia and critical care. Most available non-invasive CO measuring methods have an invasive component. We investigate "pulse wave transit time" (estimated continuous cardiac output [esCCO] a method of CO measurement that has no invasive component to its use. Materials and Methods: After institutional ethical committee approval, 14 adult (21-85 years patients undergoing surgery and requiring pulmonary artery catheter (PAC for measuring CO, were included. Postoperatively CO readings were taken simultaneously with thermodilution (TD via PAC and esCCO, whenever a change in CO was expected due to therapeutic interventions. Both monitoring methods were continued until patients′ discharge from the Intensive Care Unit and observer recording values using TD method was blinded to values measured by esCCO system. Results: Three hundred and one readings were obtained simultaneously from both methods. Correlation and concordance between the two methods was derived using Bland-Altman analysis. Measured values showed significant correlation between esCCO and TD ( r = 0.6, P < 0.001, 95% confidence limits of 0.51-0.68. Mean and (standard deviation for bias and precision were 0.13 (2.27 L/min and 6.56 (2.19 L/min, respectively. The 95% confidence interval for bias was - 4.32 to 4.58 L/min and for precision 2.27 to10.85 L/min. Conclusions: Although, esCCO is the only true non-invasive continuous CO monitor available and even though its values change proportionately to TD method (gold standard with the present degree of error its utility for clinical/therapeutic decision-making is questionable.

  19. Impact of changes in systemic vascular resistance on a novel non-invasive continuous cardiac output measurement system based on pulse wave transit time: a report of two cases

    OpenAIRE

    Ishihara, Hironori; Tsutsui, Masato

    2013-01-01

    The inaccuracy of arterial waveform analysis for measuring continuos cardiac output (CCO) associated with changes in systemic vascular resistance (SVR) has been well documented. A new non-invasive continuous cardiac output monitoring system (esCCO) mainly utilizing pulse wave transit time (PWTT) in place of arterial waveform analysis has been developed. However, the trending ability of esCCO to measure cardiac output during changes in SVR remains unclear. After a previous multicenter study on...

  20. A single-to-differential low-noise amplifier with low differential output imbalance

    Institute of Scientific and Technical Information of China (English)

    Duan Lian; Huang Wei; Ma Chengyan; He Xiaofeng; Jin Yuhua; Ye Tianchun

    2012-01-01

    This paper presents a single-ended input differential output low-noise amplifier intended for GPS applications.We propose a method to reduce the gain/amplitude and phase imbalance of a differential output exploiting the inductive coupling of a transformer or center-tapped differential inductor.A detailed analysis of the theory of imbalance reduction,as well as a discussion on the principle of choosing the dimensions of a transformer,are given.An LNA has been implemented using TSMC 0.18μm technology with ESD-protected.Measurement on board shows a voltage gain of 24.6 dB at 1.575 GHz and a noise figure of 3.2 dB.The gain imbalance is below 0.2 dB and phase imbalance is less than 2 degrees.The LNA consumes 5.2 mA from a 1.8 V supply.

  1. Resumen del documento de consenso «Guías de práctica clínica para el manejo del síndrome de bajo gasto cardiaco en el postoperatorio de cirugía cardiaca» Summary of the consensus document: «Clinical practice guide for the management of low cardiac output syndrome in the postoperative period of heart surgery»

    Directory of Open Access Journals (Sweden)

    J.L. Pérez Vela

    2012-05-01

    Full Text Available El síndrome de bajo gasto cardiaco es una potencial complicación de los pacientes intervenidos de cirugía cardiaca y asocia un aumento de la morbimortalidad. La presente guía pretende proporcionar recomendaciones para el manejo de estos pacientes, en el postoperatorio inmediato, ingresados en UCI. Las recomendaciones se han agrupado en diferentes apartados, tratando de dar respuesta desde los conceptos más básicos como es la definición a los diferentes apartados de monitorización básica y avanzada, y terminando con el complejo manejo de este síndrome. Se propone un algoritmo de manejo inicial, así como otros de fracaso ventricular predominantemente izquierdo o derecho. La mayor parte de las recomendaciones están basadas en el consenso de expertos, debido a la falta de estudios clínicos aleatorizados, de adecuado diseño y tamaño muestral en este grupo de pacientes. La calidad de la evidencia y la fuerza de las recomendaciones se realizó siguiendo la metodología GRADE. La guía se presenta como una lista de recomendaciones (y nivel de evidencia de cada recomendación para cada pregunta del tema seleccionado. A continuación, en cada pregunta, se procede a la justificación de las recomendaciones.Low cardiac output syndrome is a potential complication in cardiac surgery patients and is associated with increased morbidity and mortality. This guide provides recommendations for the management of these patients, immediately after surgery and following admission to the ICU. The recommendations are grouped into different sections, addressing from the most basic concepts such as definition of the disorder to the different sections of basic and advanced monitoring, and culminating with the complex management of this syndrome. We propose an algorithm for initial management, as well as two others for ventricular failure (predominantly left or right. Most of the recommendations are based on expert consensus, due to the lack of randomized

  2. Altered Cardiac Function and Ventricular Septal Defect in Avian Embryos Exposed to Low-Dose Trichloroethylene

    OpenAIRE

    Echoleah S Rufer; Hacker, Timothy A.; Flentke, George R.; Drake, Victoria J.; Brody, Matthew J.; Lough, John; Susan M. Smith

    2009-01-01

    Trichloroethylene (TCE) is the most frequently reported organic groundwater contaminant in the United States. It is controversial whether gestational TCE exposure causes congenital heart defects. The basis for TCE’s proposed cardiac teratogenicity is not well understood. We previously showed that chick embryos exposed to 8 ppb TCE during cardiac morphogenesis have reduced cardiac output and increased mortality. To further investigate TCE’s cardioteratogenic potential, we exposed in ovo chick ...

  3. A novel 3D detector configuration enabling high quantum efficiency, low crosstalk, and low output capacitance

    International Nuclear Information System (INIS)

    The benefits of pixelated planar direct conversion semiconductor radiation detectors comprising a thick fully depleted substrate are that they offer low crosstalk, small output capacitance, and that the planar configuration simplifies manufacturing. In order to provide high quantum efficiency for high energy X-rays and Gamma-rays such a radiation detector should be as thick as possible. The maximum thickness and thus the maximum quantum efficiency has been limited by the substrate doping concentration: the lower the substrate doping the thicker the detector can be before reaching the semiconductor material's electric breakdown field. Thick direct conversion semiconductor detectors comprising vertical three-dimensional electrodes protruding through the substrate have been previously proposed by Sherwood Parker in order to promote rapid detection of radiation. An additional advantage of these detectors is that their thickness is not limited by the substrate doping, i.e., the size of the maximum electric field value in the detector does not depend on detector thickness. However, the thicker the substrate of such three dimensional detectors is the larger the output capacitance is and thus the larger the output noise is. In the novel direct conversion pixelated radiation detector utilizing a novel three dimensional semiconductor architecture, which is proposed in this work, the detector thickness is not limited by the substrate doping and the output capacitance is small and does not depend on the detector thickness. In addition, by incorporating an additional node to the novel three-dimensional semiconductor architecture it can be utilized as a high voltage transistor that can deliver current across high voltages. Furthermore, it is possible to connect a voltage difference of any size to the proposed novel three dimensional semiconductor architecture provided that it is thick enough—this is a novel feature that has not been previously possible for semiconductor

  4. A novel 3D detector configuration enabling high quantum efficiency, low crosstalk, and low output capacitance

    Science.gov (United States)

    Aurola, A.; Marochkin, V.; Tuuva, T.

    2016-03-01

    The benefits of pixelated planar direct conversion semiconductor radiation detectors comprising a thick fully depleted substrate are that they offer low crosstalk, small output capacitance, and that the planar configuration simplifies manufacturing. In order to provide high quantum efficiency for high energy X-rays and Gamma-rays such a radiation detector should be as thick as possible. The maximum thickness and thus the maximum quantum efficiency has been limited by the substrate doping concentration: the lower the substrate doping the thicker the detector can be before reaching the semiconductor material's electric breakdown field. Thick direct conversion semiconductor detectors comprising vertical three-dimensional electrodes protruding through the substrate have been previously proposed by Sherwood Parker in order to promote rapid detection of radiation. An additional advantage of these detectors is that their thickness is not limited by the substrate doping, i.e., the size of the maximum electric field value in the detector does not depend on detector thickness. However, the thicker the substrate of such three dimensional detectors is the larger the output capacitance is and thus the larger the output noise is. In the novel direct conversion pixelated radiation detector utilizing a novel three dimensional semiconductor architecture, which is proposed in this work, the detector thickness is not limited by the substrate doping and the output capacitance is small and does not depend on the detector thickness. In addition, by incorporating an additional node to the novel three-dimensional semiconductor architecture it can be utilized as a high voltage transistor that can deliver current across high voltages. Furthermore, it is possible to connect a voltage difference of any size to the proposed novel three dimensional semiconductor architecture provided that it is thick enough—this is a novel feature that has not been previously possible for semiconductor

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

    International Nuclear Information System (INIS)

    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

  6. G16R single nucleotide polymorphism but not haplotypes of the ß2-adrenergic receptor gene alters cardiac output in humans

    DEFF Research Database (Denmark)

    Rokamp, Kim Z; Staalsø, Jonatan M; Gartmann, Martin;

    2013-01-01

    Variation in genes encoding the ß2-adrenergic receptor (ADRB2) and angiotensin-converting enzyme (ACE) may influence Q¿ (cardiac output). The 46G>A (G16R) SNP (single nucleotide polymorphism) has been associated with ß2-mediated vasodilation, but the effect of ADRB2 haplotypes on Q¿ has not been ...

  7. Design of Low Voltage Low Power CMOS OP-AMPS with Rail-to-Rail Input/Output Swing

    OpenAIRE

    Gopalaiah, SV; Shivaprasad, AP; Panigrahi, Sukanta K

    2004-01-01

    A novel input and output biasing circuit to extend the input common mode (CM) voltage range and the output swing to rail-to-rail in a low voltage op-amp in standard CMOS technology is presented. The input biasing circuit uses a Switched Capacitor Based Attenuator (SCBA) approach to establish rail-to-rail common mode input voltage range. And the output biasing circuit uses an Output Driver (OD), with floating bias to give the rail-to-rail swing at output stage. Three different OD schemes in op...

  8. The spectrum of low-output low-gradient aortic stenosis with normal ejection fraction.

    Science.gov (United States)

    Pislaru, Sorin V; Pellikka, Patricia A

    2016-05-01

    Low-flow, low-gradient (LF/LG) severe aortic stenosis (AS) with preserved ejection fraction refers to the condition of AS with aortic valve area ≤1 cm(2), stroke volume index measurement error probably being the most common cause of marked inconsistency between gradient, valve area and patient presentation. The presence of LG severe AS may be overestimated in petite patients, who may have aortic valve area slightly less than 1 cm(2)with only moderate AS. Concomitant cardiac conditions besides AS, including significant mitral and tricuspid regurgitation, intracardiac shunts and constrictive pericarditis, may contribute to reduced stroke volume, and evidence for these must be sought at the time of echocardiography. True LF/LG severe AS is associated with a unique and probably maladaptive remodelling pattern with smaller ventricles, increasing relative wall thickness, progressive worsening of diastolic function and higher afterload, as demonstrated by lower systemic arterial compliance, higher systemic vascular resistance and higher valvuloarterial impedance. Control of hypertension is essential to the appropriate management of patients with AS. Aortic valve replacement should be considered in patients with compelling evidence of severe AS who remain symptomatic despite optimal treatment of hypertension. PMID:26822426

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

    Science.gov (United States)

    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...

  10. The non-invasive and continuous estimation of cardiac output using a photoplethysmogram and electrocardiogram during incremental exercise

    International Nuclear Information System (INIS)

    Cardiac output (CO) monitoring is not only essential for critically ill patients in the hospital, but also for patients at home and those undergoing cardiopulmonary exercise testing. However, CO is difficult to monitor during daily activities and exercise. In this paper, we aim at developing a novel CO estimation method that can be used under these challenging conditions. The tube model was utilized to derive a CO index, namely the pulse time reflection ratio (PTRR) from an electrocardiogram and photoplethysmogram. After calibration, the PTRR can be used to estimate beat-to-beat CO. The proposed method was verified against CO measured by impedance cardiography on 19 healthy subjects in an incremental intensity exercise test. Results showed that there were strong correlations (r) between the PTRR and reference CO in 18 subjects (mean r: 0.88, n = 245 trials). Two calibration approaches reported in the literature were applied to the proposed method and the corresponding bias ± precisions of estimation errors were 0 ± 1.89 L min−1 and −0.22 ± 2.12 L min−1, respectively. The percent errors were 21.94% and 24.90%, smaller than the clinical acceptance limit (30%). To conclude, after calibration, this method can be used to monitor CO on healthy subjects during incremental intensity exercise

  11. Cardiac output obtained from test bolus injections as a factor in contrast injection rate revision of following coronary CT angiography

    Energy Technology Data Exchange (ETDEWEB)

    Konno, Masahiko [Division of Diagnostic Image Analysis, Graduate School of Medicine, Tohoku University, Miyagi (Japan); Yamagata Prefecture Comprehensive Rehabilitation and Education Center, Yamagata (Japan)], E-mail: mkonno@med.tohoku.ac.jp; Hosokai, Yoshiyuki; Usui, Akihito; Abe, Mitsuya; Tateishi, Toshiki; Kawasumi, Yusuke; Saito, Haruo [Division of Diagnostic Image Analysis, Graduate School of Medicine, Tohoku University, Miyagi (Japan); Tsuda, Masashi; Ota, Hideki; Takase, Kei [Division of Diagnostic Radiology, Graduate School of Medicine, Tohoku University, Miyagi (Japan)

    2012-12-15

    Background.. Optimal contrast enhancement is crucial for the detection of coronary artery stenoses and atherosclerotic changes in coronary CT angiography (CTA). Purpose To demonstrate the feasibility of using the cardiac output (CO) obtained from the test bolus injection data-set (CO test) as a factor in contrast injection rate revision of the following coronary CTA. Material and Methods. The test bolus injection data-sets of 52 consecutive coronary CTAs were examined. CO test was calculated from the test bolus data-set. Aortic peak enhancement (APE) was measured on the following coronary CTA. We simulated the APE at a fixed contrast injection rate of 4 mL/s (simAPE) in each patient. Results. The ranges of COtest and simAPE were 2.82-7.56 L/min and 194-527 Hounsfield Units, respectively. There was a significant negative correlation (R = -0.802, P < 0.001) between simAPE and COtest. Conclusion. COtest can be used for injection rate revision on coronary CTA.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Science.gov (United States)

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

    2016-01-01

    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

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

    Science.gov (United States)

    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 μg kg(-1) min(-1) and decreased by 40% from baseline (COdown) infusing sodium nitroglycerine≥30 μg kg(-1) min(-1) plus esmolol 500 μg 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

  15. Sudden Cardiac Death in Low- and Middle-Income Countries

    Science.gov (United States)

    Vedanthan, Rajesh; Fuster, Valentin; Fischer, Avi

    2015-01-01

    Cardiovascular disease, and the incidence of sudden cardiac death (SCD), will increase significantly in low- and middle-income countries (LMIC). Thus, SCD threatens to become a global public health problem. We present a summary of the current research that has investigated the epidemiology of SCD in LMIC. Few studies of SCD in LMIC exist, and they are of variable methodological quality. Risk factors for SCD are described, taking into account recent global burden of disease and risk factor statistics. We describe 1 proposal for a community-based, prospective, multiple-source methodology for SCD monitoring and surveillance that can be implemented in LMIC. Further research into the epidemiology of SCD in LMIC, using standardized methodology, would allow investigators and policy makers to determine the regions, communities, and individuals most at need for SCD prevention. Focusing on SCD and its prevention in LMIC should be a priority for the global health community. PMID:25689944

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

    OpenAIRE

    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 patter...

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

    OpenAIRE

    Lee, Qim Y; Stephen J. Redmond; Chan, Gregory SH; Middleton, Paul M; Steel, Elizabeth; Malouf, Philip; Critoph, Cristopher; Flynn, Gordon; O’Lone, Emma; Lovell, Nigel H

    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 w...

  18. Cardiac rehabilitation delivery model for low-resource settings

    Science.gov (United States)

    Grace, Sherry L; Turk-Adawi, Karam I; Contractor, Aashish; Atrey, Alison; Campbell, Norm; Derman, Wayne; Melo Ghisi, Gabriela L; Oldridge, Neil; Sarkar, Bidyut K; Yeo, Tee Joo; Lopez-Jimenez, Francisco; Mendis, Shanthi; Oh, Paul; Hu, Dayi; Sarrafzadegan, Nizal

    2016-01-01

    Objective Cardiovascular disease is a global epidemic, which is largely preventable. Cardiac rehabilitation (CR) is demonstrated to be cost-effective and efficacious in high-income countries. CR could represent an important approach to mitigate the epidemic of cardiovascular disease in lower-resource settings. The purpose of this consensus statement was to review low-cost approaches to delivering the core components of CR, to propose a testable model of CR which could feasibly be delivered in middle-income countries. Methods A literature review regarding delivery of each core CR component, namely: (1) lifestyle risk factor management (ie, physical activity, diet, tobacco and mental health), (2) medical risk factor management (eg, lipid control, blood pressure control), (3) education for self-management and (4) return to work, in low-resource settings was undertaken. Recommendations were developed based on identified articles, using a modified GRADE approach where evidence in a low-resource setting was available, or consensus where evidence was not. Results Available data on cost of CR delivery in low-resource settings suggests it is not feasible to deliver CR in low-resource settings as is delivered in high-resource ones. Strategies which can be implemented to deliver all of the core CR components in low-resource settings were summarised in practice recommendations, and approaches to patient assessment proffered. It is suggested that CR be adapted by delivery by non-physician healthcare workers, in non-clinical settings. Conclusions Advocacy to achieve political commitment for broad delivery of adapted CR services in low-resource settings is needed. PMID:27181874

  19. Differences of cardiac output measurements by open-circuit acetylene uptake in pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension: a cohort study

    Directory of Open Access Journals (Sweden)

    Schwaiblmair Martin

    2012-03-01

    Full Text Available Abstract Background As differences in gas exchange between pulmonary arterial hypertension (PAH and chronic thromboembolic pulmonary hypertension (CTEPH have been demonstrated, we asked if cardiac output measurements determined by acetylene (C2H2 uptake significantly differed in these diseases when compared to the thermodilution technique. Method Single-breath open-circuit C2H2 uptake, thermodilution, and cardiopulmonary exercise testing were performed in 72 PAH and 32 CTEPH patients. Results In PAH patients the results for cardiac output obtained by the two methods showed an acceptable agreement with a mean difference of -0.16 L/min (95% CI -2.64 to 2.32 L/min. In contrast, the agreement was poorer in the CTEPH group with the difference being -0.56 L/min (95% CI -4.96 to 3.84 L/min. Functional dead space ventilation (44.5 ± 1.6 vs. 32.2 ± 1.4%, p 2 gradient (9.9 ± 0.8 vs. 4.1 ± 0.5 mmHg, p Conclusion Cardiac output evaluation by the C2H2 technique should be interpreted with caution in CTEPH, as ventilation to perfusion mismatching might be more relevant than in PAH.

  20. Dynamic Floating Output Stage for Low Power Buffer Amplifier for LCD Application

    Directory of Open Access Journals (Sweden)

    Hari Shanker Srivastava

    2015-02-01

    Full Text Available This topic proposes low-power buffer means low quiescent current buffer amplifier. A dynamic floating current node is used at the output of two-stage amplifier to increase the charging and discharging of output capacitor as well as settling time of buffer. It is designed for 10 bit digital analog converter to support for LCD column driver it is implemented in 180 nm CMOS technology with the quiescent current of 5 µA for 30 pF capacitance, the settling time calculated as 4.5µs, the slew rate obtained as 5V/µs and area on chip is 30×72µ

  1. Comparison of transthoracic electrical bioimpedance cardiac output measurement with thermodilution method in post coronary artery bypass graft patients

    Directory of Open Access Journals (Sweden)

    Sharma Vikas

    2011-01-01

    Full Text Available Transthoracic electrical bioimpedance (TEB has been proposed as a non-invasive, continuous, and cost-effective method of cardiac output (CO measurement. In this prospective, non-randomized, clinical study, we measured CO with NICOMON (Larsen and Toubro Ltd., Mysore, India and compared it with thermodilution (TD method in patients after off-pump coronary artery bypass (OPCAB graft surgery. We also evaluated the effect of ventilation (mechanical and spontaneous on the measurement of CO by the two methods. Forty-six post-OPCAB patients were studied at five predefined time points during controlled ventilation and at five time points when breathing spontaneously. A total of 230 data pairs of CO were obtained. During controlled ventilation, TD CO values ranged from 2.29 to 6.74 L/min (mean 4.45 ± 0.85 L/min, while TEB CO values ranged from 1.70 to 6.90 L/min (mean 4.43 ± 0.94 L/min. The average correlation (r was 0.548 (P = 0.0002, accompanied by a bias of 0.015 L/min and precision of 0.859 L/min. In spontaneously breathing patients, TD CO values ranged from 2.66 to 6.92 L/min (mean 4.66 ± 0.76 L/min, while TEB CO values ranged from 3.08 to 6.90 L/min (mean 4.72 ± 0.82 L/min. Their average correlation was relatively poor (r = 0.469, P= 0.002, accompanied by a bias of −0.059 L/min and precision of 0.818 L/min. The overall percent errors between TD CO and TEB CO were 19.3% (during controlled ventilation and 17.4% (during spontaneous breathing, respectively. To conclude, a fair correlation was found between TD CO and TEB CO measurements among post-OPCAB patients during controlled ventilation. However, the correlation was weak in spontaneously breathing patients.

  2. Comparação dos efeitos da dobutamina e da milrinona sobre a hemodinâmica e o transporte de oxigênio em pacientes submetidos à cirurgia cardíaca com baixo débito cardíaco após indução anestésica Comparación de los efectos de la dobutamina y de la milrinona sobre la hemodinámica y el transporte de oxígeno en pacientes sometidos a cirugía cardiaca con bajo débito cardiaco después de inducción anestésica Comparison of the effects of dobutamine and milrinone on hemodynamic parameters and oxygen supply in patients undergoing cardiac surgery with low cardiac output after anesthetic induction

    Directory of Open Access Journals (Sweden)

    Maria José Carvalho Carmona

    2010-06-01

    Full Text Available JUSTIFICATIVA E OBJETIVOS: Diversas classes de fármacos inotrópicos, com efeitos hemodinâmicos diferentes, são utilizadas no tratamento do baixo débito cardíaco em pacientes com disfunção sistólica submetidos a procedimento cirúrgico cardíaco. O objetivo deste estudo foi comparar o efeito da dobutamina e da milrinona sobre a hemodinâmica e o transporte de oxigênio nessa população de pacientes. MÉTODO: Após aprovação do Comitê de Ética institucional e obtenção do consentimento escrito pós-informado, 20 pacientes submetidos à cirurgia cardíaca e com índice cardíaco JUSTIFICATIVA Y OBJETIVOS: Diversas clases de fármacos inotrópicos con efectos hemodinámicos diferentes, se usan en el tratamiento del bajo débito cardíaco en pacientes con disfunción sistólica sometidos al procedimiento quirúrgico cardíaco. El objetivo de este estudio, fue comparar el efecto de la dobutamina y de la milrinona sobre la hemodinámica y el transporte de oxígeno en esa población de pacientes. MÉTODO: Después de la aprobación del Comité de Ética institucional y de la obtención del consentimiento informado, 20 pacientes sometidos a la cirugía cardíaca y con índice cardíaco BACKGROUND AND OBJECTIVES: Several classes of inotropic drugs with different hemodynamic effects are used in the treatment of low cardiac output in patients with diastolic dysfunction undergoing cardiac surgery. The objective of the present study was to compare the effects of dobutamine and milrinone on hemodynamic parameters and oxygen supply in this population of patients. METHODS: After approval by the Ethics Committee of the institution and signing of the informed consent, 20 patients undergoing cardiac surgery with cardiac index < 2 L.min-1.m2 after anesthetic induction and place ment of a pulmonary artery catheter were randomly divided to receive dobutamine 5 µg.kg-1. min-1 (n = 10, or milrinone 0.5 µg.kg-1.min-1 (n = 10. Hemodynamic parameters were

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

    Science.gov (United States)

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

    2011-01-01

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

  4. Exercise-induced cardiac fatigue in low handicap polo horses

    Directory of Open Access Journals (Sweden)

    CAO Bello

    2014-01-01

    Full Text Available Physical exercise leads to several changes in the cardiovascular system of horses and may induce abnormalities that are not observed at rest. Little is known about the cardiac effects of intense physical exercise performed by horses in polo competitions. This study aimed at identifying if exercise-induced cardiac fatigue is observed in healthy polo ponies. We examined 25 equine athletes before and after a training match. The results demonstrated post-exercise electrocardiographic alteration such as cardiac arrhythmia, QTc prolongation, abnormal T waves and ST-segment elevation. The post-exercise echocardiogram showed interventricular septum and left ventricle free wall thickness reduction, systolic volume decreased and ejection fraction decreased. These results suggest that polo causes exercise-induced cardiac fatigue. It was not possible to establish accurately the etiology of this abnormality, nor its long-term consequences.

  5. Nonlinear output properties of cantilever driving low frequency piezoelectric energy harvester

    Science.gov (United States)

    Xu, Chundong; Ren, Bo; Liang, Zhu; Chen, Jianwei; Zhang, Haiwu; Yue, Qingwen; Xu, Qing; Zhao, Xiangyong; Luo, Haosu

    2012-11-01

    Cantilever driving low frequency piezoelectric energy harvester (CANDLE) has been found as a promising structure for vibration energy harvesting. This paper presents the nonlinear output properties of the CANDLE to optimize the performance of the device. Simulation results of the finite element method illustrate that nonlinear contacts between the cymbal transducers and the cantilever beam are main reasons of the nonlinear output. However, high excitation acceleration of the nonlinear leap point limits the application of the device. Based on the simulation results and theory analysis, the excitation acceleration is reduced to 30 m/s2 by increasing the proof mass.

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

    Directory of Open Access Journals (Sweden)

    Lewis JE

    2011-09-01

    Full Text Available John E Lewis1, Stacey L Tannenbaum1, Jinrun Gao3, Angelica B Melillo1, Evan G Long1, Yaima Alonso2, Janet Konefal1, Judi M Woolger2, Susanna Leonard1, Prabjot K Singh1, Lawrence Chen1, Eduard Tiozzo1 1Department of Psychiatry and Behavioral Sciences, 2Department of Medicine, University of Miami Miller School of Medicine, Miami, FL, 3State Farm Insurance, Bloomington, IL, USA Background and purpose: The Electro Sensor Complex (ESC is software that combines three devices using bioelectrical impedance, galvanic skin response, and spectrophotometry: (1 ES-BC (Electro Sensor-Body Composition; LD Technology, Miami, FL to assess body composition, (2 EIS-GS (Electro Interstitial Scan-Galvanic Skin; LD Technology to predict autonomic nervous system activity, and (3 ES Oxi (Electro Sensor Oxi; LD Technology to assess cardiac output. The objective of this study was to compare each to a standardized assessment: ES-BC to dual-energy X-ray absorptiometry (DXA, EIS-GS to heart rate variability, and ES Oxi to BioZ Dx Diagnostic System (BioZ Dx; SonoSite Inc, Bothell, WA. Patients and methods: The study was conducted in two waves. Fifty subjects were assessed for body composition and autonomic nervous system activity. Fifty-one subjects were assessed for cardiac output. Results: We found adequate relative and absolute agreement between ES-BC and DXA for fat mass (r = 0.97, P < 0.001 with ES-BC overestimating fat mass by 0.1 kg and for body fat percentage (r = 0.92, P < 0.001 with overestimation of fat percentage by 0.4%. For autonomic nervous system activity, we found marginal relative agreement between EIS-GS and heart rate variability by using EIS-GS as the predictor in a linear regression equation (adjusted R2 = 0.56, P = 0.03. For cardiac output, adequate relative and absolute agreement was found between ES Oxi and BioZ Dx at baseline (r = 0.60, P < 0.001, after the first exercise stage (r = 0.79, P < 0.001, and after the second exercise stage (r = 0.86, P

  7. The effect of an external signal on output microwave power of a low-voltage vircator

    International Nuclear Information System (INIS)

    This Letter is devoted to results of the both experimental and theoretical studies of electromagnetic radiation output power gain in the low-voltage microwave generator with a virtual cathode (vircator) under an external harmonic signal leading to the preliminary velocity modulation of the electron beam. The simple theoretical model of the electron beam with virtual cathode in a diode gap with retarding field under the external signal has been developed. The theoretical and numerical analysis have shown the possibility of power amplification in the vircator under the external influence. Obtained results of the theoretical consideration are proven by the experimental study. - Highlights: • The signal effect on vircator were studied both experimentally and theoretically. • We report the possibility of significant power amplification in vircator. • We explain mechanisms of the output power gain. • The growth of the output power exceed 5 times for the optimal pre-modulation

  8. The effect of an external signal on output microwave power of a low-voltage vircator

    Energy Technology Data Exchange (ETDEWEB)

    Phrolov, N.S.; Koronovskii, A.A. [Saratov State Technical University, Politehnicheskaja 77, Saratov 410028 (Russian Federation); Saratov State University, Astrahanskaja 83, Saratov 410012 (Russian Federation); Kalinin, Yu.A. [Saratov State Technical University, Politehnicheskaja 77, Saratov 410028 (Russian Federation); Kurkin, S.A.; Starodubov, A.V. [Saratov State Technical University, Politehnicheskaja 77, Saratov 410028 (Russian Federation); Saratov State University, Astrahanskaja 83, Saratov 410012 (Russian Federation); Hramov, A.E., E-mail: hramovae@gmail.com [Saratov State Technical University, Politehnicheskaja 77, Saratov 410028 (Russian Federation); Saratov State University, Astrahanskaja 83, Saratov 410012 (Russian Federation)

    2014-06-27

    This Letter is devoted to results of the both experimental and theoretical studies of electromagnetic radiation output power gain in the low-voltage microwave generator with a virtual cathode (vircator) under an external harmonic signal leading to the preliminary velocity modulation of the electron beam. The simple theoretical model of the electron beam with virtual cathode in a diode gap with retarding field under the external signal has been developed. The theoretical and numerical analysis have shown the possibility of power amplification in the vircator under the external influence. Obtained results of the theoretical consideration are proven by the experimental study. - Highlights: • The signal effect on vircator were studied both experimentally and theoretically. • We report the possibility of significant power amplification in vircator. • We explain mechanisms of the output power gain. • The growth of the output power exceed 5 times for the optimal pre-modulation.

  9. Clinical evaluation of the flotrac/vigileo™ system for continuous cardiac output monitoring in patients undergoing regional anesthesia for elective cesarean section: a pilot study

    Science.gov (United States)

    Auler, José Otavio C.; Torres, Marcelo L. A.; Cardoso, Mônica M.; Tebaldi, Thais C.; Schmidt, André P.; Kondo, Mario M.; Zugaib, Marcelo

    2010-01-01

    BACKGROUND: Spinal anesthesia for cesarean delivery may cause severe maternal hypotension and a decrease in cardiac output. Compared to assessment of cardiac output via a pulmonary artery catheter, the FloTrac/Vigileo™ system may offer a less invasive technique. The aim of this study was to evaluate cardiac output and other hemodynamic measurements made using the FloTrac/Vigileo™ system in patients undergoing spinal anesthesia for elective cesarean section. METHODS: A prospective study enrolling 10 healthy pregnant women was performed. Hemodynamic parameters were continuously obtained at 15 main points: admission to surgery (two baseline measurements), after preload, after spinal anesthesia administration and 4 time points thereafter (4, 6, 8 and 10 min after anesthesia), at skin and uterine incision, newborn and placental delivery, oxytocin administration, end of surgery, and recovery from anesthesia. Hemodynamic therapy was guided by mean arterial pressure, and vasopressors were used as appropriate to maintain baseline values. A repeated measures ANOVA was used for data analysis. RESULTS: There was a significant increase in heart rate and a decrease of stroke volume and stroke volume index up to 10 min after spinal anesthesia (P < 0.01). Importantly, stroke volume variation increased immediately after newborn delivery (P < 0.001) and returned to basal values at the end of surgery. Further hemodynamic parameters showed no significant changes over time. DISCUSSION AND CONCLUSIONS: No significant hemodynamic effects, except for heart rate and stroke volume changes, were observed in pregnant women managed with preload and vasopressors when undergoing elective cesarean section and spinal anesthesia. PMID:20835557

  10. Clinical evaluation of the flotrac/vigileo™ system for continuous cardiac output monitoring in patients undergoing regional anesthesia for elective cesarean section: a pilot study

    Directory of Open Access Journals (Sweden)

    José Otavio Costa Auler Junior

    2010-06-01

    Full Text Available BACKGROUND: Spinal anesthesia for cesarean delivery may cause severe maternal hypotension and a decrease in cardiac output. Compared to assessment of cardiac output via a pulmonary artery catheter, the FloTrac/Vigileo™ system may offer a less invasive technique. The aim of this study was to evaluate cardiac output and other hemodynamic measurements made using the FloTrac/Vigileo™ system in patients undergoing spinal anesthesia for elective cesarean section. METHODS: A prospective study enrolling 10 healthy pregnant women was performed. Hemodynamic parameters were continuously obtained at 15 main points: admission to surgery (two baseline measurements, after preload, after spinal anesthesia administration and 4 time points thereafter (4, 6, 8 and 10 min after anesthesia, at skin and uterine incision, newborn and placental delivery, oxytocin administration, end of surgery, and recovery from anesthesia. Hemodynamic therapy was guided by mean arterial pressure, and vasopressors were used as appropriate to maintain baseline values. A repeated measures ANOVA was used for data analysis. RESULTS: There was a significant increase in heart rate and a decrease of stroke volume and stroke volume index up to 10 min after spinal anesthesia (P < 0.01. Importantly, stroke volume variation increased immediately after newborn delivery (P < 0.001 and returned to basal values at the end of surgery. Further hemodynamic parameters showed no significant changes over time. DISCUSSION AND CONCLUSIONS: No significant hemodynamic effects, except for heart rate and stroke volume changes, were observed in pregnant women managed with preload and vasopressors when undergoing elective cesarean section and spinal anesthesia.

  11. Programmable Gain Amplifiers with DC Suppression and Low Output Offset for Bioelectric Sensors

    Directory of Open Access Journals (Sweden)

    Alonso Alonso

    2013-09-01

    Full Text Available DC-offset and DC-suppression are key parameters in bioelectric amplifiers. However, specific DC analyses are not often explained. Several factors influence the DC-budget: the programmable gain, the programmable cut-off frequencies for high pass filtering and, the low cut-off values and the capacitor blocking issues involved. A new intermediate stage is proposed to address the DC problem entirely. Two implementations were tested. The stage is composed of a programmable gain amplifier (PGA with DC-rejection and low output offset. Cut-off frequencies are selectable and values from 0.016 to 31.83 Hz were tested, and the capacitor deblocking is embedded in the design. Hence, this PGA delivers most of the required gain with constant low output offset, notwithstanding the gain or cut-off frequency selected.

  12. A Case of Femoral Arteriovenous Fistula Causing High-Output Cardiac Failure, Originally Misdiagnosed as Chronic Fatigue Syndrome

    OpenAIRE

    Porter, J; Al-Jarrah, Q.; Richardson, S

    2014-01-01

    Percutaneous arterial catheterisation is commonly undertaken for a range of diagnostic and interventional procedures. Iatrogenic femoral arteriovenous fistulas are an uncommon complication of these procedures. Most are asymptomatic and close spontaneously, but can rarely increase in size leading to the development of symptoms. We report a case of an iatrogenic femoral arteriovenous fistula, causing worsening congestive cardiac failure, in a 34-year-old marathon runner. This was originally dia...

  13. Uncalibrated pulse power analysis fails to reliably measure cardiac output in patients undergoing coronary artery bypass surgery

    OpenAIRE

    Broch, Ole; Renner, Jochen; Höcker, Jan; Gruenewald, Matthias; Meybohm, Patrick; Schöttler, Jan; Steinfath, Markus; Bein, Berthold

    2011-01-01

    Introduction Uncalibrated arterial pulse power analysis has been recently introduced for continuous monitoring of cardiac index (CI). The aim of the present study was to compare the accuracy of arterial pulse power analysis with intermittent transpulmonary thermodilution (TPTD) before and after cardiopulmonary bypass (CPB). Methods Forty-two patients scheduled for elective coronary surgery were studied after induction of anaesthesia, before and after CPB respectively. Each patient was monitor...

  14. Ultra Low Complexity Soft Output Detector for Non-Binary LDPC Coded Large MIMO Systems

    CERN Document Server

    Suthisopapan, Puripong; Kasai, Kenta; Imtawil, Virasit

    2012-01-01

    The theoretic results of MIMO capacity tell us that the higher the number of antennas are employed, the higher the transmission rate is. This makes MIMO systems with hundreds of antennas very attractive but one of the major problems that obstructs such large dimensional MIMO systems from the practical realization is a high complexity of the MIMO detector. We present in this paper the new soft output MIMO detector based on matched filtering that can be applied to the large MIMO systems which are coded by the powerful non-binary LDPC codes. The per-bit complexity of the proposed detector is just 0.28% to that of low complexity soft output MMSE detector and scales only linearly with a number of antennas. Furthermore, the coded performances with small information length 800 bits are within 4.2 dB from the associated MIMO capacity.

  15. Carotid-cardiac baroreflex influence on forearm vascular resistance during low level LBNP

    Science.gov (United States)

    Ludwig, David

    1990-01-01

    Twelve healthy males were tested at low levels of lower body negative pressure (LBNP) with and without artificial stimulation of the carotid-cardiac baroreceptors. The carotid-cardiac baroreceptors were stimulated by applying a pressure of 10 mmHg to the carotid artery via a pressurized neck chamber. During the procedure, forearm blood flow (FBF) and forearm vascular resistance (FVR) were measured using a Whitney mercury silastic strain gauge technique. FBF decreased while FVR increased with increased intensity of LBNP. Both FBF and FVR were unaffected by carotid-cardiac baroreceptor stimulation.

  16. Comparison of remifentanil and low-dose fentanyl for fast-track cardiac anesthesia

    DEFF Research Database (Denmark)

    Khanykin, Boris; Siddiqi, Rizwan; Jensen, Per F; Bigler, Dennis R; Atroshchenko, Gennady V

    2013-01-01

    the drug infusion, which may increase the risk of an ischemic event. We conducted this randomized study to compare the efficacy of remifentanil versus low doses of fentanyl in fast-track cardiac anesthesia. It has been hypothesized that remifentanil would provide a safe anesthesia with no impact on...... myocardial function and with positive effects on extubation time and mobilization. METHODS: We compared the postoperative course of patients, the remifentanil group (RG) and the low-dose fentanyl group (LDFG), in whom remifentanil and low-dose fentanyl, respectively, were used for fast-track cardiac...... myocardial function. Both remifentanil and low-dose fentanyl are equally effective and safe for fast-track cardiac anesthesia. The study did not highlight any statistical superiority of remifentanil anesthesia over low-dose fentanyl anesthesia....

  17. Sustainable Agricultural Model of High Output, Low Input and Less Pollution in Paddy Field

    Institute of Scientific and Technical Information of China (English)

    TANG Long-fei; HUANG Yi-bin; WENG Bo-qi; LIU Zhong-zhu; LIU Xia-shi

    2001-01-01

    A model of sustainable agriculture of "high output, low input and less pollution" (HLL model)in paddy (Oryza L. )fields has been developed. About 10 - 13t/ha of rice and 3 - 4t/ha of fish were harvested by adopting the comprehensive technical system. The amount of chemical fertilizer and pesticide decreased by about 50%, thus greatly controlled the environmental pollution, and simultaneously decreased the methane emission. It was concluded that these comprehensive techniques for this model should be popularized.

  18. Output microwave radiation power of low-voltage vircator with external inhomogeneous magnetic field

    Science.gov (United States)

    Kurkin, S. A.; Koronovskii, A. A.; Hramov, A. E.

    2011-04-01

    Dependence of the power of a broadband microwave radiation generated by a low-voltage oscillator with virtual cathode (vircator) on the parameters of an external inhomogeneous magnetic field has been studied by numerical simulations using a two-dimensional model. It is established that there are optimum parameters of the generator (configuration of the external magnetic field, electron beam current) for which the output radiation power is maximum. A relationship between the optimum conditions of virtual cathode formation in the electron beam and the microwave generation regime is established.

  19. The effect of an external signal on output microwave power of a low-voltage vircator

    Science.gov (United States)

    Phrolov, N. S.; Koronovskii, A. A.; Kalinin, Yu. A.; Kurkin, S. A.; Starodubov, A. V.; Hramov, A. E.

    2014-06-01

    This Letter is devoted to results of the both experimental and theoretical studies of electromagnetic radiation output power gain in the low-voltage microwave generator with a virtual cathode (vircator) under an external harmonic signal leading to the preliminary velocity modulation of the electron beam. The simple theoretical model of the electron beam with virtual cathode in a diode gap with retarding field under the external signal has been developed. The theoretical and numerical analysis have shown the possibility of power amplification in the vircator under the external influence. Obtained results of the theoretical consideration are proven by the experimental study.

  20. Usefulness of Low Cardiac Index to Predict Sleep-Disordered Breathing in Chronic Thromboembolic Pulmonary Hypertension.

    Science.gov (United States)

    Orr, Jeremy E; Auger, William R; DeYoung, Pamela N; Kim, Nick H; Malhotra, Atul; Owens, Robert L

    2016-03-15

    Patients with chronic thromboembolic pulmonary hypertension (CTEPH) often have substantial right ventricular dysfunction. The resulting low cardiac index might predispose to sleep disordered breathing (SDB) by increasing ventilatory instability. The prevalence of SDB and potential association with impaired cardiac index was examined in patients with CTEPH. Patients referred for evaluation for pulmonary thromboendarterectomy surgery were recruited. Subjects underwent a sleep study, unless already using positive airway pressure therapy. Hemodynamic data were obtained from contemporaneous right-sided cardiac catheterization. A total of 49 subjects were included. SDB-defined as ongoing positive airway pressure use or apnea-hypopnea index (AHI) ≥5/h-was found in 57% of subjects. SDB was generally mild in severity, with respiratory events mainly consisting of hypopneas. Cardiac index was found to be significantly lower in subjects with SDB than those without (2.19 vs 2.55 L/min/m(2); p = 0.024), whereas no differences were observed in other characteristics. Additionally, cardiac index was independently predictive of AHI. In a subgroup of subjects with an elevated percentage of central events, both cardiac index and lung to finger circulation time correlated with AHI. In conclusion, SDB is prevalent in patients with CTEPH and might decrease with treatments that improve cardiac index. PMID:26805659

  1. A Case of Femoral Arteriovenous Fistula Causing High-Output Cardiac Failure, Originally Misdiagnosed as Chronic Fatigue Syndrome

    Directory of Open Access Journals (Sweden)

    J. Porter

    2014-01-01

    Full Text Available Percutaneous arterial catheterisation is commonly undertaken for a range of diagnostic and interventional procedures. Iatrogenic femoral arteriovenous fistulas are an uncommon complication of these procedures. Most are asymptomatic and close spontaneously, but can rarely increase in size leading to the development of symptoms. We report a case of an iatrogenic femoral arteriovenous fistula, causing worsening congestive cardiac failure, in a 34-year-old marathon runner. This was originally diagnosed as chronic fatigue syndrome. Following clinical examination, duplex ultrasound, and CT angiography a significant arteriovenous fistula was confirmed. Elective open surgery was performed, leading to a dramatic and rapid improvement in symptoms. Femoral arteriovenous fistulas have the potential to cause significant haemodynamic effects and can present many years after the initial procedure. Conservative, endovascular, and open surgical management strategies are available.

  2. Use of transesophageal Doppler as a sole cardiac output monitor for reperfusion hemodynamic changes during living donor liver transplantation: An observational study

    Directory of Open Access Journals (Sweden)

    M Hussien

    2011-01-01

    Full Text Available Aims: To report the use of transesophageal Doppler (TED, a minimally invasive cardiac output (COP monitor, before, during and after reperfusion and study its effect on anesthetic management during living donor liver transplantation (LDLT. Setting and Design: A prospective observational study. Methods: A total of 25 consecutive recipients with a MELD score between 15 and 20 were enrolled. Data were recorded at baseline (TB; anhepatic phase (TA; and post-reperfusion - 1, 5, 10 and 30 minutes. Fluid therapy was guided by corrected flow time (FTc of the TED. Packed red blood cells (RBCs were only given when hematocrit was less than 25%. Rotational thromboelastometry (ROTEM and standard laboratory tests were used to guide component blood products requirements. Results: Post-reperfusion, the COP, Cardiac Index (CI and stroke volume (SV increased significantly at all points of measurements; this was associated with a significant decrease in systemic vascular resistance (SVR ( P <.05. Immediately post-reperfusion, for 5 minutes, mean arterial blood pressure (ABP dropped significantly (P<.05, and 14 out of the 25 patients required boluses of epinephrine (10 μg to restore the mean ABP; 3 of the 14 patients required norepinephrine infusion till the end of surgery. Central venous pressure (CVP and urine output (UOP at all measures were maintained adequately with FTc-guided fluid replacement. Eight out of the 25 patients required no blood transfusion, and 4 of the 8 patients required no catecholamine support. Conclusion: TED as a sole monitor for COP was able to present significant and reliable changes in the cardiovascular status of the recipients during reperfusion, which could help to guide fluid- and drug-supportive therapy in this population of patients. This preliminary study needs to be applied on a larger scale.

  3. A high throughput architecture for a low complexity soft-output demapping algorithm

    Science.gov (United States)

    Ali, I.; Wasenmüller, U.; Wehn, N.

    2015-11-01

    Iterative channel decoders such as Turbo-Code and LDPC decoders show exceptional performance and therefore they are a part of many wireless communication receivers nowadays. These decoders require a soft input, i.e., the logarithmic likelihood ratio (LLR) of the received bits with a typical quantization of 4 to 6 bits. For computing the LLR values from a received complex symbol, a soft demapper is employed in the receiver. The implementation cost of traditional soft-output demapping methods is relatively large in high order modulation systems, and therefore low complexity demapping algorithms are indispensable in low power receivers. In the presence of multiple wireless communication standards where each standard defines multiple modulation schemes, there is a need to have an efficient demapper architecture covering all the flexibility requirements of these standards. Another challenge associated with hardware implementation of the demapper is to achieve a very high throughput in double iterative systems, for instance, MIMO and Code-Aided Synchronization. In this paper, we present a comprehensive communication and hardware performance evaluation of low complexity soft-output demapping algorithms to select the best algorithm for implementation. The main goal of this work is to design a high throughput, flexible, and area efficient architecture. We describe architectures to execute the investigated algorithms. We implement these architectures on a FPGA device to evaluate their hardware performance. The work has resulted in a hardware architecture based on the figured out best low complexity algorithm delivering a high throughput of 166 Msymbols/second for Gray mapped 16-QAM modulation on Virtex-5. This efficient architecture occupies only 127 slice registers, 248 slice LUTs and 2 DSP48Es.

  4. Optimal piston motion for maximum net output work of Daniel cam engines with low heat rejection

    International Nuclear Information System (INIS)

    Highlights: • The piston motion of low heat rejection compression ignition engines is optimized. • A realistic model taking into account the cooling system is developed. • The optimized cam is smaller for cylinders without thermal insulation. • The optimized cam size depends on ignition moment and cooling process intensity. - Abstract: Compression ignition engines based on classical tapper-crank systems cannot provide optimal piston motion. Cam engines are more appropriate for this purpose. In this paper the piston motion of a Daniel cam engine is optimized. Piston acceleration is taken as a control. The objective is to maximize the net output work during the compression and power strokes. A major research effort has been allocated in the last two decades for the development of low heat rejection engines. A thermally insulated cylinder is considered and a realistic model taking into account the cooling system is developed. The sinusoidal approximation of piston motion in the classical tapper-crank system overestimates the engine efficiency. The exact description of the piston motion in tapper-crank system is used here as a reference. The radiation process has negligible effects during the optimization. The approach with no constraint on piston acceleration is a reasonable approximation. The net output work is much larger (by 12–13%) for the optimized system than for the classical tapper-crank system, for similar thickness of cylinder walls and thermal insulation. Low heat rejection measures are not of significant importance for optimized cam engines. The optimized cam is smaller for a cylinder without thermal insulation than for an insulated cylinder (by up to 8%, depending on the local polar radius). The auto-ignition moment is not a parameter of significant importance for optimized cam engines. However, for given cylinder wall and insulation materials there is an optimum auto-ignition moment which maximizes the net output work. The optimum auto

  5. Low power low temperature poly-Si thin-film transistor shift register with DC-type output driver

    Science.gov (United States)

    Song, Seok-Jeong; Kim, Byung Hoon; Jang, Jin; Nam, Hyoungsik

    2015-09-01

    This paper demonstrates a low power DC-type low temperature poly-Si (LTPS) thin-film transistor (TFT) shift register that consists of nine TFTs and one bootstrapping capacitor. The proposed circuit connects large size pull-up TFTs of output drivers to positive supply instead of alternating clock signals in order to reduce substantially the power consumption of clock drivers. The SPICE simulation ensures that the variable overlap intervals can be programmed by the delay between clock signals and the overall power consumption of a DC-type circuit can be reduced to 45% of an AC-type one for a full-HD display. The operation of a proposed structure is also verified with a fabricated 16-stage gate driver.

  6. Use of a capillary input function with cardiac output for the estimation of lesion pharmacokinetic parameters: preliminary results on a breast cancer patient

    Science.gov (United States)

    Di Giovanni, P.; Ahearn, T. S.; Semple, S. I.; Azlan, C. A.; Lloyd, W. K. C.; Gilbert, F. J.; Redpath, T. W.

    2011-03-01

    The objective of this work was to propose and demonstrate a novel technique for the assessment of tumour pharmacokinetic parameters together with a regionally estimated vascular input function. A breast cancer patient T2*-weighted dynamic contrast enhanced MRI (DCE-MRI) dataset acquired at high temporal resolution during the first-pass bolus perfusion was used for testing the technique. Extraction of the lesion volume transfer constant Ktrans together with the intravascular plasma volume fraction vp was achieved by optimizing a capillary input function with a measure of cardiac output using the principle of intravascular indicator dilution theory. For a region of interest drawn within the breast lesion a vp of 0.16 and a Ktrans of 0.70 min-1 were estimated. Despite the value of vp being higher than expected, estimated Ktrans was in accordance with the literature values. In conclusion, the technique proposed here, has the main advantage of allowing the estimation of breast tumour pharmacokinetic parameters from first-pass perfusion T2*-weighted DCE-MRI data without the need of measuring an arterial input function. The technique may also have applicability to T1-weighted DCE-MRI data.

  7. Low Power Continuous-Time Delta-Sigma ADC with Current Output DAC

    DEFF Research Database (Denmark)

    Marker-Villumsen, Niels; Jørgensen, Ivan Harald Holger; Bruun, Erik

    2015-01-01

    The paper presents a continuous-time (CT) DeltaSigma (∆Σ) analog-to-digital converter (ADC) using a current output digital-to-analog converter (DAC) for the feedback. From circuit analysis it is shown that using a current output DAC makes it possible to relax the noise requirements of the 1st...

  8. Chronic myofascial pain: management by low-output helium-neon laser therapy.

    Science.gov (United States)

    Waylonis, G W; Wilke, S; O'Toole, D; Waylonis, D A; Waylonis, D B

    1988-12-01

    Therapeutic benefits of low-output helium-neon laser therapy have not been established, but laser therapy has been suggested as an effective means of treating many acute and chronic musculoskeletal pain syndromes. Although not released for general clinical use by the FA, the helium-neon laser has been promoted to physical therapists and athletic trainers as potentially useful for the treatment of pain syndromes. In particular, it has been proposed that it may be more effective than conventional measures such as medication and conventional physical therapy in the treatment of myofascial pain syndromes (fibrositis, fibromyalgia). The citations in the literature include only case reports. Sixty-two patients were treated by using acupuncture points. Two sessions of five treatments were given six weeks apart. A crossover double-blind technique was used in the treatments. The clinical responses were assessed using portions of the McGill Pain Questionnaire. No statistical difference between the treatment and the placebo groups could be determined. PMID:3063230

  9. Low body weight and cardiac tolerance to ischemia in neonatal rats

    Czech Academy of Sciences Publication Activity Database

    Chvojková, Zuzana; Ošťádalová, Ivana; Ošťádal, Bohuslav

    2005-01-01

    Roč. 54, č. 4 (2005), s. 357-362. ISSN 0862-8408 R&D Projects: GA ČR(CZ) GA305/00/1659; GA MŠk(CZ) LN00A069 Institutional research plan: CEZ:AV0Z5011922 Keywords : low body weight * cardiac tolerance to ischemia * neonatal rats Subject RIV: ED - Physiology Impact factor: 1.806, year: 2005

  10. Low Power Very High Frequency Switch-Mode Power Supply with 50 V Input and 5 V Output

    DEFF Research Database (Denmark)

    Madsen, Mickey Pierre; Knott, Arnold; Andersen, Michael A. E.

    2014-01-01

    This paper presents the design of a resonant converter with a switching frequency in the very high frequencyrange (30-300 MHz), a large step down ratio (10 times) and low output power (1 W). Several different invertersand rectifiers are analyzed and compared. The class E inverter and rectifier ar...

  11. Ranking Hearing Aid Input-Output Functions for Understanding Low-, Conversational-, and High-Level Speech in Multitalker Babble

    Science.gov (United States)

    Chung, King; Killion, Mead C.; Christensen, Laurel A.

    2007-01-01

    Purpose: To determine the rankings of 6 input-output functions for understanding low-level, conversational, and high-level speech in multitalker babble without manipulating volume control for listeners with normal hearing, flat sensorineural hearing loss, and mildly sloping sensorineural hearing loss. Method: Peak clipping, compression limiting,…

  12. Eruptive history of a low-frequency and low-output rate Pleistocene volcano, Ciomadul, South Harghita Mts., Romania

    Science.gov (United States)

    Szakács, Alexandru; Seghedi, Ioan; Pécskay, Zoltán; Mirea, Viorel

    2015-02-01

    up of peripheral domes and then concentrating in its central part. Ciomadul appears as a small-volume (ca. 8.74 km3) and very low-frequency and low-output rate volcano (ca. 9 km3/Myr) at the terminus of a gradually diminishing and extinguishing volcanic range. A number of geodynamically active features strongly suggest that the magma plumbing system beneath Ciomadul is not completely frozen, so future activity cannot be ruled out.

  13. Pediatric cardiac postoperative care

    Directory of Open Access Journals (Sweden)

    Auler Jr. José Otávio Costa

    2002-01-01

    Full Text Available The Heart Institute of the University of São Paulo, Medical School is a referral center for the treatment of congenital heart diseases of neonates and infants. In the recent years, the excellent surgical results obtained in our institution may be in part due to modern anesthetic care and to postoperative care based on well-structured protocols. The purpose of this article is to review unique aspects of neonate cardiovascular physiology, the impact of extracorporeal circulation on postoperative evolution, and the prescription for pharmacological support of acute cardiac dysfunction based on our cardiac unit protocols. The main causes of low cardiac output after surgical correction of heart congenital disease are reviewed, and methods of treatment and support are proposed as derived from the relevant literature and our protocols.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-06-15

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

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

    International Nuclear Information System (INIS)

    Purpose: To investigate a first pass analysis technique to measure absolute flow from low dose CT images in a cardiac phantom. This technique can be combined with a myocardial mass assignment to yield absolute perfusion using only two volume scans and reduce the radiation dose to the patient. Methods: A four-chamber cardiac phantom and perfusion chamber were constructed from poly-acrylic and connected with tubing to approximate anatomical features. The system was connected to a pulsatile pump, input/output reservoirs and power contrast injector. Flow was varied in the range of 1-2.67 mL/s with the pump operating at 60 beats/min. The system was imaged once a second for 14 seconds with a 320-row scanner (Toshiba Medical Systems) using a contrast-enhanced, prospective-gated cardiac perfusion protocol. Flow was calculated by the following steps: subsequent images of the perfusion volume were subtracted to find the contrast entering the volume; this was normalized by an upstream, known volume region to convert Hounsfield (HU) values to concentration; this was divided by the subtracted images time difference. The technique requires a relatively stable input contrast concentration and no contrast can leave the perfusion volume before the flow measurement is completed. Results: The flow calculated from the images showed an excellent correlation with the known rates. The data was fit to a linear function with slope 1.03, intercept 0.02 and an R2 value of 0.99. The average root mean square (RMS) error was 0.15 mL/s and the average standard deviation was 0.14 mL/s. The flow rate was stable within 7.7% across the full scan and served to validate model assumptions. Conclusion: Accurate, absolute flow rates were measured from CT images using a conservation of mass model. Measurements can be made using two volume scans which can substantially reduce the radiation dose compared with current dynamic perfusion techniques

  16. Combined effect of low doses of propranolol and ethanol on cardiac function: A comparative study by radionuclide ventriculography in conscious dogs

    International Nuclear Information System (INIS)

    Trained, chronically, instrumented, conscious dogs were used to evaluate the effect of propranolol (PRO) ethanol (ETH) or their combination (P+E) on the left ventricular (LV) function by first-pass radionuclide ventriculography (RNV). Six dogs were trained prior to a sterile left thoracotomy, where a left atrial catheter was implanted. After recovery of four days RNV was carried out by injecting a bolus technetium-99m diethylenetriamine pentaacetic acid via the catheter to the left atrium. The data was collected for 12 sec. to a computer by frame rate of 20 frames/sec. from left lateral view of the dog. The experiments were performed both in four-leg standing and in 60-degree head-up tilted positions. After control measurements the data were obtained with 0.5 mg/kg of PRO, 0.45 g/kg of ETH and their combination. The P+E combination increased significantly LV end-diastolic and end-systolic volumes, whereas LV peak ejection rate and ejection fraction were decreased. Upright position diminished the LV volume and increased heart rate, while ejection fraction and cardiac output remanined unchanged. The first-pass RNV method proved to be promising for measuring the cardiac pharmacological effects in conscious dogs. The combination of propranolol and ethanol in low doses induced an unexpectedly strong depression of LV function, which is supposed to be followed of latent cardiac depressing effect of ETH revealed by blockade of compensatory adrenergic mechanisms with PRO. (author)

  17. GaAs-based superluminescent diodes with window-like facet structure for low spectral modulation at high output powers

    Science.gov (United States)

    Ghazal, O. M. S.; Childs, D. T.; Stevens, B. J.; Babazadeh, N.; Hogg, R. A.; Groom, K. M.

    2016-04-01

    We demonstrate a GaAs-based superluminescent diode (SLD) based on the incorporation of a window-like back facet into a self-aligned stripe structure in order to reduce the effective facet reflectivity. This allows the realisation of SLDs with low spectral modulation depth (SMD) at high power spectral density (PSD), without the application of anti-reflection coatings to either facet. This approach is therefore compatible with ultra-broadband gain active elements. We show that 30 mW output power can be attained in a narrow bandwidth, corresponding to 2.2 mW nm-1 PSD with only 5% SMD, centred about 990 nm. We discuss the design criteria for high power and low SMD and the deviation from a linear dependence of SMD on output power, resulting from Joule heating in the self-aligned stripe.

  18. Three-phase power supply, output 60v and 100a, with unit power factor and low RFI level

    Directory of Open Access Journals (Sweden)

    João Batista Vieira Júnior

    2003-01-01

    Full Text Available This paper presents a three-phase rectifier, unit power factor, non-dissipative commutation in DC-DC converter and synchronized control in frequency, working with 89% of global efficiency and low level do RFI. The proposed structure allows the operation with high switching frequency. The output voltage is controlled by PWM with a constant frequency. The operation principle, theoretical analysis from DC converter, relevant equations, current balance control technique and experimental results, are shown in this paper.

  19. Evaluating the use of fibrin glue for sealing low-output enterocutaneous fistulas: study protocol for a randomized controlled trial

    OpenAIRE

    Wu, Xiuwen; Ren, Jianan; Wang, Gefei; Wang, Jianzhong; Wang, Feng; Fan, Yueping; Li, Yuanxin; Han, Gang; ZHOU, YANBING; SONG, Xiaofei; Quan, Bin; Yao, Min; Li, Jieshou

    2015-01-01

    Background The management of an enterocutaneous fistula poses a significant challenge to surgeons and is often associated with a costly hospital stay and long-term discomfort. The use of fibrin glue in the fistula tract has been shown to promote closure of low output enterocutaneous fistulas. Our previous nonrandomized study demonstrated that autologous platelet-rich fibrin glue treatment significantly decreased time to fistula closure and promoted closure rates. However, there are several li...

  20. Zinc oxide integrated area efficient high output low power wavy channel thin film transistor

    KAUST Repository

    Hanna, A. N.

    2013-11-26

    We report an atomic layer deposition based zinc oxide channel material integrated thin film transistor using wavy channel architecture allowing expansion of the transistor width in the vertical direction using the fin type features. The experimental devices show area efficiency, higher normalized output current, and relatively lower power consumption compared to the planar architecture. This performance gain is attributed to the increased device width and an enhanced applied electric field due to the architecture when compared to a back gated planar device with the same process conditions.

  1. From irradiance to output power fluctuations: the pv plant as a low pass filter

    OpenAIRE

    de Marcos, Javier; Marroyo, Luis; Lorenzo Pigueiras, Eduardo; Alvira, David; Izco, Eloisa

    2011-01-01

    The power generated by large grid-connected photovoltaic (PV) plants depends greatly on the solar irradiance. This paper studies the effects of the solar irradiance variability analyzing experimental 1-s data collected throughout a year at six PV plants, totaling 18 MWp. Each PV plant was modeled as a first order filter function based on an analysis in the frequency domain of the irradiance data and the output power signals. An empiric expression which relates the filter parameters and the PV...

  2. Anatomical-based partial volume correction for low-dose dedicated cardiac SPECT/CT

    Science.gov (United States)

    Liu, Hui; Chan, Chung; Grobshtein, Yariv; Ma, Tianyu; Liu, Yaqiang; Wang, Shi; Stacy, Mitchel R.; Sinusas, Albert J.; Liu, Chi

    2015-09-01

    Due to the limited spatial resolution, partial volume effect has been a major degrading factor on quantitative accuracy in emission tomography systems. This study aims to investigate the performance of several anatomical-based partial volume correction (PVC) methods for a dedicated cardiac SPECT/CT system (GE Discovery NM/CT 570c) with focused field-of-view over a clinically relevant range of high and low count levels for two different radiotracer distributions. These PVC methods include perturbation geometry transfer matrix (pGTM), pGTM followed by multi-target correction (MTC), pGTM with known concentration in blood pool, the former followed by MTC and our newly proposed methods, which perform the MTC method iteratively, where the mean values in all regions are estimated and updated by the MTC-corrected images each time in the iterative process. The NCAT phantom was simulated for cardiovascular imaging with 99mTc-tetrofosmin, a myocardial perfusion agent, and 99mTc-red blood cell (RBC), a pure intravascular imaging agent. Images were acquired at six different count levels to investigate the performance of PVC methods in both high and low count levels for low-dose applications. We performed two large animal in vivo cardiac imaging experiments following injection of 99mTc-RBC for evaluation of intramyocardial blood volume (IMBV). The simulation results showed our proposed iterative methods provide superior performance than other existing PVC methods in terms of image quality, quantitative accuracy, and reproducibility (standard deviation), particularly for low-count data. The iterative approaches are robust for both 99mTc-tetrofosmin perfusion imaging and 99mTc-RBC imaging of IMBV and blood pool activity even at low count levels. The animal study results indicated the effectiveness of PVC to correct the overestimation of IMBV due to blood pool contamination. In conclusion, the iterative PVC methods can achieve more accurate quantification, particularly for low

  3. C- Reactive protein, cardiac troponin T and low albumin are predictors of mortality in hemodialysis patients

    Directory of Open Access Journals (Sweden)

    Bagheri Nazila

    2009-01-01

    Full Text Available Overall and cardiovascular mortality are significantly higher in hemodialysis patients with elevated C-reactive protein (CRP. The aim of study was to determine whether CRP, low albumin and troponin are markers of overall and cardiovascular mortality in hemodialysis patients. 138 stable hemodialysis patients were divided into 2 groups n= 66 patients with coronary disease equivalent (known coronary or peripheral vascular disease or diabetes mellitus and n= 72 patients without it. The two groups were then stratified by biomarkers [cardiac troponin T and Albumin and highly sensitive CRP (hs-CRP] and followed for 30 months. The primary outcome was all causes mortality. Patients with coronary disease equivalents had 3.5 fold greater annual mortality compared to controls (24%% vs 6.9%, P value = 0.005. Elevated troponin T had a further increase in the risk for death while hs-CRP and low albumin were not associated with risk of death In conclusion, circu-lating cardiac troponin-T was associated with poor prognosis especially in hemodialysis patients with coronary risk factors.

  4. Improving Low-dose Cardiac CT Images based on 3D Sparse Representation

    Science.gov (United States)

    Shi, Luyao; Hu, Yining; Chen, Yang; Yin, Xindao; Shu, Huazhong; Luo, Limin; Coatrieux, Jean-Louis

    2016-03-01

    Cardiac computed tomography (CCT) is a reliable and accurate tool for diagnosis of coronary artery diseases and is also frequently used in surgery guidance. Low-dose scans should be considered in order to alleviate the harm to patients caused by X-ray radiation. However, low dose CT (LDCT) images tend to be degraded by quantum noise and streak artifacts. In order to improve the cardiac LDCT image quality, a 3D sparse representation-based processing (3D SR) is proposed by exploiting the sparsity and regularity of 3D anatomical features in CCT. The proposed method was evaluated by a clinical study of 14 patients. The performance of the proposed method was compared to the 2D spares representation-based processing (2D SR) and the state-of-the-art noise reduction algorithm BM4D. The visual assessment, quantitative assessment and qualitative assessment results show that the proposed approach can lead to effective noise/artifact suppression and detail preservation. Compared to the other two tested methods, 3D SR method can obtain results with image quality most close to the reference standard dose CT (SDCT) images.

  5. Low Power Digital Clock Design Using LVCMOS Input/Output Standards on 45nm FPGA

    DEFF Research Database (Denmark)

    Pandey, Sujeet; Mehta, Rishabh; Kalia, Kartik;

    2016-01-01

    How wonderful it would be if every device we use is energy efficient. This is an approach to design an efficient digital clock that consumes low amount of power. This is done by varying frequency to different levels and checking corresponding amount of energy consumed. Low Voltage Complementary m...

  6. Left ventricular AV-plane displacement is preserved with lifelong endurance training and is the main determinant of maximal cardiac output

    DEFF Research Database (Denmark)

    Steding-Ehrenborg, Katarina; Boushel, Robert C; Calbet, José A; Åkeson, Per; Mortensen, Stefan P

    2015-01-01

    BACKGROUND: Age-related decline in cardiac function can be prevented or postponed by lifelong endurance training. However, effects of normal ageing as well as of lifelong endurance exercise on longitudinal and radial contribution to stroke volume are unknown. The aim of this study was to determine...

  7. NONINVASIVE CARDIAC OUTPUT MONITORING DURING EXERCISE TESTING: NEXFIN PULSE CONTOUR ANALYSIS COMPARED TO AN INERT GAS REBREATHING METHOD AND RESPIRED GAS ANALYSIS

    NARCIS (Netherlands)

    S.A. Bartels; W.J. Stok; R. Bezemer; R.J. Boksem; J Goudoever; T.G.V. Cherpanath; J.J. van Lieshout; B.E. Westerhof; J.M. Karemaker; C. Ince

    2011-01-01

    Purpose. Exercise testing is often used to assess cardiac function during physical exertion to obtain diagnostic information. However, this procedure is limited to measuring the electrical activity of the heart using electrocardiography and intermittent blood pressure (BP) measurements and does not

  8. Cardiac diffusion tensor imaging based on compressed sensing using joint sparsity and low-rank approximation.

    Science.gov (United States)

    Huang, Jianping; Wang, Lihui; Chu, Chunyu; Zhang, Yanli; Liu, Wanyu; Zhu, Yuemin

    2016-04-29

    Diffusion tensor magnetic resonance (DTMR) imaging and diffusion tensor imaging (DTI) have been widely used to probe noninvasively biological tissue structures. However, DTI suffers from long acquisition times, which limit its practical and clinical applications. This paper proposes a new Compressed Sensing (CS) reconstruction method that employs joint sparsity and rank deficiency to reconstruct cardiac DTMR images from undersampled k-space data. Diffusion-weighted images acquired in different diffusion directions were firstly stacked as columns to form the matrix. The matrix was row sparse in the transform domain and had a low rank. These two properties were then incorporated into the CS reconstruction framework. The underlying constrained optimization problem was finally solved by the first-order fast method. Experiments were carried out on both simulation and real human cardiac DTMR images. The results demonstrated that the proposed approach had lower reconstruction errors for DTI indices, including fractional anisotropy (FA) and mean diffusivities (MD), compared to the existing CS-DTMR image reconstruction techniques. PMID:27163322

  9. An optimized self-powered switching circuit for non-linear energy harvesting with low voltage output

    International Nuclear Information System (INIS)

    Harvesting energy from environmental sources has been of particular interest these last few years. Microgenerators that can power electronic systems are a solution for the conception of autonomous, wireless devices. They allow the removal of bulky and costly wiring, as well as complex maintenance and environmental issues for battery-powered systems. In particular, using piezoelectric generators for converting vibrational energy to electrical energy is an intensively investigated field. In this domain, it has been shown that the harvested energy can be greatly improved by the use of an original non-linear treatment of the piezoelectric voltage called SSHI (Synchronized Switch Harvesting on Inductor), which consists in intermittently switching the piezoelectric element on a resonant electrical network for a very short time. However, the integration of miniaturized microgenerators with low voltage output (e.g. MEMS microgenerators) has not been widely studied. In the case of low voltage output, the losses introduced by voltage gaps of discrete components such as diodes or transistors can no longer be neglected. Therefore the purpose of this paper is to propose a model that takes into account such losses as well as a new architecture for the SSHI energy harvesting circuit that limits such losses in the harvesting process. While most of the study uses an externally powered microcontroller for the non-linear treatment, this circuit is fully self-powered, thus providing an enhanced autonomous microgenerator. In particular this circuit aims at limiting the effect of non-linear components with a voltage gap such as diodes. It is shown both theoretically and experimentally that the harvested power can be significantly increased using such a circuit. In particular, experimental measurements performed on a cantilever beam show that the circuit allows a 160% increase of the harvested power compared to a standard energy harvesting circuit, while the classical implementation of

  10. Comparison of sub- and supercritical Organic Rankine Cycles for power generation from low-temperature/low-enthalpy geothermal wells, considering specific net power output and efficiency

    International Nuclear Information System (INIS)

    Electrical power production at low-enthalpy (∼150 °C) geothermal sites is usually realized using an Organic Rankine Cycle (ORC process). This paper presents our analysis of sub- and supercritical processes using propane, carbon dioxide and ten other refrigerants as working fluids. The impact of crucial indicators for optimization, such as specific net power, thermal efficiency and heat input is discussed in detail. The focus was to optimize the thermodynamic loop and the influence of other parameters, such as condensing temperature, minimal temperature difference in the heat exchanger, and internal heat recovery. Simulations showed that at a geothermal fluid temperature of 150 °C, a suitable working fluid such as propane or R143a can increase specific net power output up to 40%. Furthermore, systematic simulations on brine temperatures of 130–170 °C from subcritical to supercritical operation are discussed. Results from this research may also be applicable for electricity generation using waste heat from combined heat and power (CHP) plants or other technical processes. -- Highlights: ► Geothermal power generation from low-temperature sources of around 150 °C. ► Simulation of sub- and supercritical Organic Rankine Cycles. ► Propane, CO2 and 10 other refrigerants as working fluids investigated. ► Power output optimization by variation of the steam conditions. ► Increase of power output with supercritical cycles and suitable working fluid

  11. A low power and low distortion rail-to-rail input/output amplifier using constant current technique

    International Nuclear Information System (INIS)

    A rail-to-rail amplifier with constant transconductance, intended for audio processing, is presented. The constant transconductance is obtained by a constant current technique based on the input differential pairs operating in the weak inversion region. MOSFETs working in the weak inversion region have the advantages of low power and low distortion. The proposed rail-to-rail amplifier, fabricated in a standard 0.35 μm CMOS process, occupies a core die area of 75 x 183 μm2. Measured results show that the maximum power consumption is 85.37 μW with a supply voltage of 3.3 V and the total harmonic distortion level is 1.2% at 2 kHz. (semiconductor integrated circuits)

  12. A low power and low distortion rail-to-rail input/output amplifier using constant current technique

    Science.gov (United States)

    Yan, Liu; Yiqiang, Zhao; Shilin, Zhang; Hongliang, Zhao

    2011-04-01

    A rail-to-rail amplifier with constant transconductance, intended for audio processing, is presented. The constant transconductance is obtained by a constant current technique based on the input differential pairs operating in the weak inversion region. MOSFETs working in the weak inversion region have the advantages of low power and low distortion. The proposed rail-to-rail amplifier, fabricated in a standard 0.35 μm CMOS process, occupies a core die area of 75 × 183 μm2. Measured results show that the maximum power consumption is 85.37 μW with a supply voltage of 3.3 V and the total harmonic distortion level is 1.2% at 2 kHz.

  13. Determinación y análisis comparativo de gasto cardíaco en enfermos críticos mediante Doppler transesofágico y termodilución en bolos: Experiencia preliminar Comparison of cardiac output measurement in critical patients using transesophageal Doppler or thermodilution: A preliminary report

    Directory of Open Access Journals (Sweden)

    Max Andresen H

    2005-07-01

    Full Text Available Background: Cardiac output can be measured non invasively by transesophageal Doppler. This is an alternative to measure it by thermodilution with a catheter in the pulmonary artery. Aim: To compare both methods of cardiac output measurement. Material and methods: Simultaneous measurement of cardiac output by transesophageal Doppler and thermodilution with a catheter in the pulmonary artery in four male critical patients, aged 60±12 years, hospitalized in a University Hospital. The Bland and Altman method to compare the concordance between two measurements, was used. Results: Forty measurements were performed. The results of both methods had a correlation coefficient of 0.98. According to the Bland and Altman method, the difference between both methods was -0.5 L with a precision of 0.52 L/min (95% confidence interval -1.51 to 0.52 L/min. Considering that a change between two sequential measurements is considered significant when the difference is more than 15%, both measurements agreed in 83% of cases, that there was a change in cardiac output. Conclusions:Transesophageal Doppler is a promising non invasive technique to measure cardiac output in critical care patients. It becomes a valid alternative to the thermodilution technique. This preliminary experience must be confirmed in a larger series

  14. Improving low-dose cardiac CT images using 3D sparse representation based processing

    Science.gov (United States)

    Shi, Luyao; Chen, Yang; Luo, Limin

    2015-03-01

    Cardiac computed tomography (CCT) has been widely used in diagnoses of coronary artery diseases due to the continuously improving temporal and spatial resolution. When helical CT with a lower pitch scanning mode is used, the effective radiation dose can be significant when compared to other radiological exams. Many methods have been developed to reduce radiation dose in coronary CT exams including high pitch scans using dual source CT scanners and step-and-shot scanning mode for both single source and dual source CT scanners. Additionally, software methods have also been proposed to reduce noise in the reconstructed CT images and thus offering the opportunity to reduce radiation dose while maintaining the desired diagnostic performance of a certain imaging task. In this paper, we propose that low-dose scans should be considered in order to avoid the harm from accumulating unnecessary X-ray radiation. However, low dose CT (LDCT) images tend to be degraded by quantum noise and streak artifacts. Accordingly, in this paper, a 3D dictionary representation based image processing method is proposed to reduce CT image noise. Information on both spatial and temporal structure continuity is utilized in sparse representation to improve the performance of the image processing method. Clinical cases were used to validate the proposed method.

  15. Breeding for resistance to gastrointestinal nematodes - the potential in low-input/output small ruminant production systems.

    Science.gov (United States)

    Zvinorova, P I; Halimani, T E; Muchadeyi, F C; Matika, O; Riggio, V; Dzama, K

    2016-07-30

    The control of gastrointestinal nematodes (GIN) is mainly based on the use of drugs, grazing management, use of copper oxide wire particles and bioactive forages. Resistance to anthelmintic drugs in small ruminants is documented worldwide. Host genetic resistance to parasites, has been increasingly used as a complementary control strategy, along with the conventional intervention methods mentioned above. Genetic diversity in resistance to GIN has been well studied in experimental and commercial flocks in temperate climates and more developed economies. However, there are very few report outputs from the more extensive low-input/output smallholder systems in developing and emerging countries. Furthermore, results on quantitative trait loci (QTL) associated with nematode resistance from various studies have not always been consistent, mainly due to the different nematodes studied, different host breeds, ages, climates, natural infections versus artificial challenges, infection level at sampling periods, among others. The increasing use of genetic markers (Single Nucleotide Polymorphisms, SNPs) in GWAS or the use of whole genome sequence data and a plethora of analytic methods offer the potential to identify loci or regions associated nematode resistance. Genomic selection as a genome-wide level method overcomes the need to identify candidate genes. Benefits in genomic selection are now being realised in dairy cattle and sheep under commercial settings in the more advanced countries. However, despite the commercial benefits of using these tools, there are practical problems associated with incorporating the use of marker-assisted selection or genomic selection in low-input/output smallholder farming systems breeding schemes. Unlike anthelmintic resistance, there is no empirical evidence suggesting that nematodes will evolve rapidly in response to resistant hosts. The strategy of nematode control has evolved to a more practical manipulation of host-parasite equilibrium

  16. Lactotripeptides effect on office and 24-h ambulatory blood pressure, blood pressure stress response, pulse wave velocity and cardiac output in patients with high-normal blood pressure or first-degree hypertension: a randomized double-blind clinical trial.

    Science.gov (United States)

    Cicero, Arrigo F G; Rosticci, Martina; Gerocarni, Beatrice; Bacchelli, Stefano; Veronesi, Maddalena; Strocchi, Enrico; Borghi, Claudio

    2011-09-01

    Contrasting data partially support a certain antihypertensive efficacy of lactotripeptides (LTPs) derived from enzymatic treatment of casein hydrolysate. Our aim was to evaluate this effect on a large number of hemodynamic parameters. We conducted a prospective double-blind randomized clinical trial, which included 52 patients affected by high-normal blood pressure (BP) or first-degree hypertension. We investigated the effect of a 6-week treatment with the LTPs isoleucine-proline-proline and valine-proline-proline at 3 mg per day, assumed to be functional food, on office BP, 24-h ambulatory BP monitoring (ABPM) values, stress-induced BP increase and cardiac output-related parameters. In the LTP-treated subjects, we observed a significant reduction in office systolic BP (SBP; -5±8 mm Hg, P=0.013) and a significant improvement in pulse wave velocity (PWV; -0.66±0.81 m s(-1), P=0.001; an instrumental biomarker of vascular rigidity). No effect on 24-h ABPM parameters and BP reaction to stress was observed from treatment with the combined LTPs. LTPs, but not placebo, were associated with a mild but significant change in the stroke volume (SV), SV index (markers of cardiac flow), the acceleration index (ACI) and velocity index (VI) (markers of cardiac contractility). No effect was observed on parameters related to fluid dynamics or vascular resistance. LTPs positively influenced the office SBP, PWV, SV, SV index, ACI and VI in patients with high-normal BP or first-degree hypertension. PMID:21753776

  17. Cardiac sarcoidosis

    OpenAIRE

    Costello BT; Nadel J.; Taylor AJ

    2016-01-01

    Benedict T Costello,1,2 James Nadel,3 Andrew J Taylor,1,21Department of Cardiovascular Medicine, The Alfred Hospital, 2Baker IDI Heart and Diabetes Research Institute, Melbourne, VIC, 3School of Medicine, University of Notre Dame, Sydney, NSW, Australia Abstract: Cardiac sarcoidosis is a rare but life-threatening condition, requiring a high degree of clinical suspicion and low threshold for investigation to make the diagnosis. The cardiac manifestations include heart failure, conducting syst...

  18. Effect of high or low protamine dosing on postoperative bleeding following heparin anticoagulation in cardiac surgery. A randomised clinical trial.

    Science.gov (United States)

    Meesters, Michael I; Veerhoek, Dennis; de Lange, Fellery; de Vries, Jacob-Willem; de Jong, Jan R; Romijn, Johannes W A; Kelchtermans, Hilde; Huskens, Dana; van der Steeg, Robin; Thomas, Pepijn W A; Burtman, David T M; van Barneveld, Laurentius J M; Vonk, Alexander B A; Boer, Christa

    2016-08-01

    While experimental data state that protamine exerts intrinsic anticoagulation effects, protamine is still frequently overdosed for heparin neutralisation during cardiac surgery with cardiopulmonary bypass (CPB). Since comparative studies are lacking, we assessed the influence of two protamine-to-heparin dosing ratios on perioperative haemostasis and bleeding, and hypothesised that protamine overdosing impairs the coagulation status following cardiac surgery. In this open-label, multicentre, single-blinded, randomised controlled trial, patients undergoing on-pump coronary artery bypass graft surgery were assigned to a low (0.8; n=49) or high (1.3; n=47) protamine-to-heparin dosing group. The primary outcome was 24-hour blood loss. Patient haemostasis was monitored using rotational thromboelastometry and a thrombin generation assay. The low protamine-to-heparin dosing ratio group received less protamine (329 ± 95 vs 539 ± 117 mg; pblood loss was increased in the high dosing ratio group (615 ml; 95 % CI 500-830 ml vs 470 ml; 95 % CI 420-530 ml; p=0.021) when compared to the low dosing group, respectively. More patients in the high dosing group received fresh frozen plasma (11 % vs 0 %; p=0.02) and platelet concentrate (21 % vs 6 %; p=0.04) compared to the low dosing group. Our study confirms in vitro data that abundant protamine dosing is associated with increased postoperative blood loss and higher transfusion rates in cardiac surgery. PMID:27277211

  19. Low Molecular Weight Fucoidan Alleviates Cardiac Dysfunction in Diabetic Goto-Kakizaki Rats by Reducing Oxidative Stress and Cardiomyocyte Apoptosis

    Directory of Open Access Journals (Sweden)

    Xinfeng Yu

    2014-01-01

    Full Text Available Diabetic cardiomyopathy (DCM is characterized by cardiac dysfunction and cardiomyocyte apoptosis. Oxidative stress is suggested to be the major contributor to the development of DCM. This study was intended to evaluate the protective effect of low molecular weight fucoidan (LMWF against cardiac dysfunction in diabetic rats. Type 2 diabetic goto-kakizaki rats were untreated or treated with LMWF (50 and 100 mg/kg/day for three months. The establishment of DCM model and the effects of LMWF on cardiac function were evaluated by echocardiography and isolated heart perfusion. Ventricle staining with H-E or Sirius Red was performed to investigate the structural changes in myocardium. Functional evaluation demonstrated that LMWF has a beneficial effect on DCM by enhancing myocardial contractility and mitigating cardiac fibrosis. Additionally, LMWF exerted significant inhibitory effects on the reactive oxygen species production and myocyte apoptosis in diabetic hearts. The depressed activity of superoxide dismutase in diabetic heart was also improved by intervention with LMWF. Moreover, LMWF robustly inhibited the enhanced expression of protein kinase C β, an important contributor to oxidative stress, in diabetic heart and high glucose-treated cardiomyocytes. In conclusion, LMWF possesses a protective effect against DCM through ameliorations of PKCβ-mediated oxidative stress and subsequent cardiomyocyte apoptosis in diabetes.

  20. Design of an Output Feedback Controller for STATCOM in view of Low Frequency Oscillation Damping Using HBMO and PSO

    Directory of Open Access Journals (Sweden)

    masoud aliakbar golkar

    2011-11-01

    Full Text Available Nowadays since the speed of reaching to response is getting more important, the random searching algorithms are mostly used instead of the overall search of the problem space. This paper presents the application and the performance comparison of HBMO and PSO optimization techniques for designing an output feedback damping controller for STATCOM in order to enhance the damping of power system. The problem of the damping controller design is considered as an optimization problem with a multi-purpose criterion function and it is solved by HBMO and PSO algorithms. This controller is designed in order to transmit unstable electromechanical modes to the specific area of the complex plane. The proposed controller performance is confirmed by the analysis of the eigenvalue and nonlinear time-domain simulation under various disturbances with both control parameters of STATCOM (capacitor voltage control and terminal voltage control. Simulation results illustrate that the designed controller by HBMO performs better than PSO in finding the solution. Moreover, the design of the controller based on the capacitor voltage control in comparison with terminal voltage control has better low frequency oscillation damping and it increases the dynamical stability of the power system.

  1. Application and Nursing of Pulse Index Continuous Cardiac Output Monitoring in Patients with Post-cardiac Arrest Syndrome%脉波指示剂连续心排血量监测在心搏骤停后综合征患者中的应用与护理

    Institute of Scientific and Technical Information of China (English)

    陈淑兰; 刘刚; 张秋真; 陈秋恋

    2011-01-01

    Objective To investigate the application effect and nursing of the pulse index continuous cardiac output (PICCO) monitoring technique in patients with post-cardiac arrest syndrome (PCAS). Methods The precautions and nursing points were developed for the flowsheet of operation, cooperation for the vein catheterization and measurements. Results Of the 15 patients using the PICCO monitoring technique in early stage,no complication occurred ,except one patient died of multiple organ failure and 3 abandoned the treatment,and the rest 11 patients survived. Conclusion PCAS patients undergoing PICCO monitoring device in the early stage can efficiently assist the fluid management,maintain the vital signs of the patients,and save their lives.%目的 探讨脉波指示剂连续心排血量监测( pulse index continuous cardiac output,PICCO)在心搏骤停后综合征(postcardiac arrest syndrome,PCAS)患者中的应用效果及护理.方法 制定操作流程、置管配合、测量的注意事项和护理要点.结果 15例患者通过早期采用了PICCO监测,并采取了相应的护理措施,均未出现并发症,除了1例患者因多器官功能衰竭死亡外,3例患者放弃治疗,其余11例患者均存活.结论 对PCAS患者早期进行PICCO监测,能对患者进行更准确的血流动力学监测,可以有效协助液体管理,维持患者生命体征的稳定,挽救患者生命.

  2. Association of Low Ficolin-Lectin Pathway Parameters with Cardiac Syndrome X.

    Science.gov (United States)

    Horváth, Z; Csuka, D; Vargova, K; Leé, S; Varga, L; Garred, P; Préda, I; Zsámboki, E T; Prohászka, Z; Kiss, R G

    2016-09-01

    In patients with typical angina pectoris, inducible myocardial ischaemia and macroscopically normal coronaries (cardiac syndrome X (CSX)), a significantly elevated plasma level of terminal complement complex (TCC), the common end product of complement activation, has been observed without accompanying activation of the classical or the alternative pathways. Therefore, our aim was to clarify the role of the ficolin-lectin pathway in CSX. Eighteen patients with CSX, 37 stable angina patients with significant coronary stenosis (CHD) and 54 healthy volunteers (HC) were enrolled. Serum levels of ficolin-2 and ficolin-3, ficolin-3/MASP-2 complex and ficolin-3-mediated TCC deposition (FCN3-TCC) were determined. Plasma level of TCC was significantly higher in the CSX than in the HC or CHD group (5.45 versus 1.30 versus 2.04 AU/ml, P TCC deposition was significantly lower in the CSX group compared to the HC and CHD groups (67.8% versus 143.3% or 159.7%, P TCC and FCN3-TCC level (r = 0.507, P = 0.032) and between ficolin-3/MASP-2 complex level and FCN3-TCC deposition (r = 0.651, P = 0.003). In conclusion, in patients with typical angina and myocardial ischaemia despite macroscopically normal coronary arteries, low levels of several lectin pathway parameters were observed, indicating complement activation and consumption. Complement activation through the ficolin-lectin pathway might play a role in the complex pathomechanism of CSX. PMID:27312152

  3. Low vitamin D concentration is not associated with increased mortality and morbidity after cardiac surgery.

    Directory of Open Access Journals (Sweden)

    Alparslan Turan

    Full Text Available OBJECTIVE: To determine the effect of vitamin D on postoperative outcomes in cardiac surgical patients. DESIGN: Retrospective study. SETTING: Single institution-teaching hospital. PARTICIPANTS: Adult cardiac surgical patients with perioperative 25-hydroxyvitamin D measurements. INTERVENTIONS: None. We gathered information from the Cardiac Anesthesiology Registry that was obtained at the time of the patients' visit/hospitalization. MEASUREMENTS AND MAIN RESULTS: We used data of 18,064 patients from the Cardiac Anesthesiology Registry; 426 patients with 25-hydroxyvitamin D measurements met our inclusion criteria. Association with Vitamin D concentration and composite of 11 cardiac morbidities was done by multivariate (i.e., multiple outcomes per subject analysis. For other outcomes separate multivariable logistic regressions and adjusting for the potential confounders was used. The observed median vitamin D concentration was 19 [Q1-Q3∶12, 30] ng/mL. Vitamin D concentration was not associated with our primary composite of serious cardiac morbidities (odds ratio [OR], 0.96; 95% CI, 0.86-1.07. Vitamin D concentration was also not associated with any of the secondary outcomes: neurologic morbidity (P = 0.27, surgical (P = 0.26 or systemic infections (P = 0.58, 30-day mortality (P = 0.55, or length of initial intensive care unit (ICU stay (P = 0.04. CONCLUSIONS: Our analysis suggests that perioperative vitamin D concentration is not associated with clinically important outcomes, likely because the outcomes are overwhelmingly determined by other baseline and surgical factors.

  4. Effect of phytase supplementation on apparent phosphorus digestibility and phosphorus output in broiler chicks fed low-phosphorus diets

    Directory of Open Access Journals (Sweden)

    Xian-Ren Jiang

    2015-04-01

    Full Text Available This study was conducted to evaluate the effect of supplemental phytase in broiler chicks fed different low levels of total phosphorus (P on the apparent phosphorus digestibility (APD and phosphorus output (PO in the faeces and ileal digesta. After fed a standard broiler starter diet from day 0 to 14 post-hatch, a total of 144 male broiler chicks were allocated to 6 groups for a 7-d experiment with a 2 × 3 factorial design comparing phytase (supplemented without (CTR or with 400 FTU/kg phytase (PHY and total P levels (2.0, 2.5 and 3.0 g/kg. The faecal samples were collected from day 17 to 21 post-hatch. At 22 days of age, all the chicks were slaughtered and collected the ileal digesta. Phytase supplementation significantly (P < 0.01 increased APD and decreased PO in the faeces and ileal digesta in comparison with the CTR group. In addition, PO in the faeces expressed as g/kg DM diets and faeces (Diet × P level, P = 0.047 and < 0.01, respectively as well as PO in the ileal digesta expressed as g/kg DM digesta (Diet × P level, P = 0.04 were affected by diet and P level, which were due to the significant reduction (P < 0.01 by PHY supplementation to the diets with 3.0 g/kg total P. The results evidenced that supplemental phytase improved the APD and PO when chicks was fed 3.0 g/kg total P diet, while lower total P levels may limit exogenous phytase efficacy.

  5. Cardiac contractility, central haemodynamics and blood pressure regulation during semistarvation

    DEFF Research Database (Denmark)

    Stokholm, K H; Breum, L; Astrup, A

    1991-01-01

    pressure (BP) declined. The fall in BP was caused by the reduction in cardiac output as the total peripheral resistance was unchanged. Finally, the decline in total blood volume was not significant. These findings together with a reduction in heart rate indicated that a reduced sympathetic tone via......Eight obese patients were studied before and after 2 weeks of treatment by a very-low-calorie diet (VLCD). Cardiac output and central blood volume (pulmonary blood volume and left atrial volume) were determined by indicator dilution (125I-albumin) and radionuclide angiocardiography (first pass and...... equilibrium technique by [99Tcm]red blood cells). Cardiac output decreased concomitantly with the reduction in oxygen uptake as the calculated systemic arteriovenous difference of oxygen was unaltered. There were no significant decreases in left ventricular contractility indices, i.e. the ejection fraction...

  6. Effect of Low Amphetamine Doses on Cardiac Responses to Emotional Stress in Aged Rats

    NARCIS (Netherlands)

    Nyakas, Csaba; Buwalda, Bauke; Luiten, Paul G.M.; Bohus, Bela

    1992-01-01

    In young Wistar rats conditioned emotional stress can be characterized by a learned bradycardiac response to an inescapable footshock. In aged rats this bradycardiac response is attenuated and accompanied by suppressed behavioral arousal in response to novelty. In the present study, cardiac response

  7. Design of Low-Noise Output Amplifiers for P-channel Charge-Coupled Devices Fabricated on High-Resistivity Silicon

    Energy Technology Data Exchange (ETDEWEB)

    Haque, S; Frost, F Dion R.; Groulx, R; Holland, S E; Karcher, A; Kolbe, W F; Roe, N A; Wang, G; Yu, Y

    2011-12-22

    We describe the design and optimization of low-noise, single-stage output amplifiers for p-channel charge-coupled devices (CCDs) used for scientific applications in astronomy and other fields. The CCDs are fabricated on high-resistivity, 4000–5000 -cm, n-type silicon substrates. Single-stage amplifiers with different output structure designs and technologies have been characterized. The standard output amplifier is designed with an n{sup +} polysilicon gate that has a metal connection to the sense node. In an effort to lower the output amplifier readout noise by minimizing the capacitance seen at the sense node, buried-contact technology has been investigated. In this case, the output transistor has a p{sup +} polysilicon gate that connects directly to the p{sup +} sense node. Output structures with buried-contact areas as small as 2 μm × 2 μm are characterized. In addition, the geometry of the source-follower transistor was varied, and we report test results on the conversion gain and noise of the various amplifier structures. By use of buried-contact technology, better amplifier geometry, optimization of the amplifier biases and improvements in the test electronics design, we obtain a 45% reduction in noise, corresponding to 1.7 e{sup -} rms at 70 kpixels/sec.

  8. Troponin not just a simple cardiac marker: prognostic significance of cardiac troponin

    Institute of Scientific and Technical Information of China (English)

    Benny Mulyanto Setiadi; LEI Han; CHANG Jing

    2009-01-01

    Objective The object of this study was to review the role of cardiac troponin as a prognostic factor in acute coronary syndrome patients of varying circumstances.Data sources The data used in this review were obtained mainly from the studies of cardiac troponin reported in pubmed from 1981 to 2006.Study selection Relevant articles on studies of cardiac troponin were selected.Results Elevated cardiac troponin in patients with ST elevation and non ST elevation myocardial infarction was associated with adverse outcomes, including a higher incidence of congestive heart failure, shock, and death. Patients with elevated cardiac troponin value seemed to benefit more from invasive strategies including a percutaneous coronary intervention and bypass surgery, but elevated cardiac troponin was also correlated with adverse outcomes, including a higher degree of failure, shock, and mortality in patients undergoing percutaneous coronary intervention; a higher degree of perioperative myocardial infarction, low cardiac output syndrome, cardiopulmonary resuscitation, and new-onset ventricular arrhythmia in patients undergoing bypass surgery were also observed. Elevated troponin after a percutaneous coronary intervention seemed to be associated with short-term adverse outcomes rather than long-term adverse outcomes, unless the elevation of the troponin post percutaneous coronary intervention was quite high (about 5 times above normal). On the contrary, elevated cardiac troponin after bypass surgery was more confusing to analyze since it happened in almost all patients. Furthermore, differences in cutoff values and time measurements in some studies add more confusion; thus, further research is warranted.Conclusions The prognostic value of cardiac troponin is demonstrated in almost all acute coronary syndrome patients. In addition to its high sensitivity and specificity, the prognostic value of cardiac troponin is another reason to make it the "golden cardiac marker' of this time.

  9. Kommentar zu: Efficacy and safety of intravenous levosimendan compared with dobutamine in severe low-output heart failure (the LIDO study: a randomized double-blind trial

    Directory of Open Access Journals (Sweden)

    Follath F

    2002-01-01

    Full Text Available Verglichen mit Dobutamin führt die Verabreichung von Levosimendan zu einer signifikanten Steigerung der Überlebensrate bei an Low-Output-Syndrom leidenden Patienten. Dies zeigten sowohl die nach 31 Tagen wie auch nach 180 Tagen vorgenommenen Erhebungen.

  10. Investigation of the influence of electron-velocity dispersion on the output characteristics of a laboratory breadboard of a low-voltage vircator

    Science.gov (United States)

    Kalinin, Yu. A.; Fokin, A. S.

    2014-03-01

    Some ways of forming multivelocity electron beams are considered, and experimental dependences (obtained on a laboratory breadboard of a low-voltage vircator) of the integral output power and generation band on the electron-velocity dispersion in a beam are shown.

  11. Study of industrial consumption behavior in the conditions of low power consumption and decrease of pollution using input-output analysis

    International Nuclear Information System (INIS)

    This study, regarding the industrial consumption behaviour at low power consumption and under low pollution constraints, making use of the input-output analysis, is based on models for prices, energy demand, and pollution. Numerical applications were developed by use of MATILDA program and the methods of setting the model parameters and data acquisition are presented. The analysis provided prognoses for pollution coefficients for given price and consumption input data and very important data for industrial consumption behavior. (author) 7 refs

  12. Evaluation of bluetooth low power for physiological monitoring in a home based cardiac rehabilitation program.

    Science.gov (United States)

    Martin, Timothy; Ding, Hang; D'Souza, Matthew; Karunanithi, Mohan

    2012-01-01

    Cardiovascular disease (CVD) is the leading cause of mortality in Australia, and places large burdens on the healthcare system. To assist patients with CVDs in recovering from cardiac events and mediating cardiac risk factors, a home based cardiac rehabilitation program, known as the Care Assessment Platform (CAP), was developed. In the CAP program, patients are required to manually enter health information into their mobile phones on a daily basis. The manual operation is often subject to human errors and is inconvenient for some elderly patients. To improve this, an automated wireless solution has been desired. The objectives of this paper are to investigate the feasibility of implementing the newly released Bluetooth 4.0 (BT4.0) for the CAP program, and practically evaluate BT4.0 communications between a developed mobile application and some emulated healthcare devices. The study demonstrated that BT4.0 addresses usability, interoperability and security for healthcare applications, reduces the power consumption in wireless communication, and improves the flexibility of interface for software development. This evaluation study provides an essential mobile BT4.0 framework to incorporate a large range of healthcare devices for clinical assessment and intervention in the CAP program, and hence it is useful for similar development and research work of other mobile healthcare solutions. PMID:22797030

  13. A Wearable Contactless Sensor Suitable for Continuous Simultaneous Monitoring of Respiration and Cardiac Activity

    OpenAIRE

    Gargiulo, Gaetano D; Upul Gunawardana; Aiden O’Loughlin; Mohammad Sadozai; Elham Shabani Varaki; Breen, Paul P.

    2015-01-01

    A reliable system that can simultaneously and accurately monitor respiration and cardiac output would have great utility in healthcare applications. In this paper we present a novel approach to creating such a system. This noninvasive, low power, low cost, contactless sensor is suitable for continuous monitoring of respiration (tidal volume) and cardiac stroke volume. Furthermore, it is capable of delivering this data in true volume (i.e., mL). The current embodiment, specifically designed fo...

  14. A low-power bidirectional telemetry device with a near-field charging feature for a cardiac microstimulator.

    Science.gov (United States)

    Shuenn-Yuh Lee; Chih-Jen Cheng; Ming-Chun Liang

    2011-08-01

    In this paper, wireless telemetry using the near-field coupling technique with round-wire coils for an implanted cardiac microstimulator is presented. The proposed system possesses an external powering amplifier and an internal bidirectional microstimulator. The energy of the microstimulator is provided by a rectifier that can efficiently charge a rechargeable device. A fully integrated regulator and a charge pump circuit are included to generate a stable, low-voltage, and high-potential supply voltage, respectively. A miniature digital processor includes a phase-shift-keying (PSK) demodulator to decode the transmission data and a self-protective system controller to operate the entire system. To acquire the cardiac signal, a low-voltage and low-power monitoring analog front end (MAFE) performs immediate threshold detection and data conversion. In addition, the pacing circuit, which consists of a pulse generator (PG) and its digital-to-analog (D/A) controller, is responsible for stimulating heart tissue. The chip was fabricated by Taiwan Semiconductor Manufacturing Company (TSMC) with 0.35-μm complementary metal-oxide semiconductor technology to perform the monitoring and pacing functions with inductively powered communication. Using a model with lead and heart tissue on measurement, a -5-V pulse at a stimulating frequency of 60 beats per minute (bpm) is delivered while only consuming 31.5 μW of power. PMID:23851950

  15. Cardiac tamponade and successful pericardiocentesis in an extremely low birth weight neonate with percutaneously inserted central venous line: a case report

    OpenAIRE

    Pizzuti, Alfredo; Parodi, Emilia; Abbondi, Paola; Frigerio, Mario

    2010-01-01

    Background Pericardial effusion and cardiac tamponade are rare but life-threatening complications of percutaneosuly inserted central line (PICL) use in extremely low birth weight (ELBW) neonates, with an incidence reported between 0.07% and 2% of PICLs placement. Timely diagnosis and pericardiocentesis has been proven to be life-saving. Case presentation The patient was a 620 g birth weight neonate who presented with sudden cardiac instability 18 days after the insertion of a PICL and in spit...

  16. Low-pressure cardiac tamponade masquerading as severe sepsis diagnosed with a bedside ultrasound and as the initial presentation of malignancy

    Directory of Open Access Journals (Sweden)

    Ricardo Augusto Slaibi Conti

    2014-07-01

    Full Text Available Objective: We report a patient with low-pressure cardiac tamponade masquerading as sepsis and as the initial presentation of malignancy. A quick diagnosis was done by the intensivist performing a bedside ultrasound. Background: The diagnosis of low-pressure cardiac tamponade is a challenge because the classic physical signs of cardiac tamponade can be absent. It is made even more challenging when the vital sign changes and physical examination findings mimic severe sepsis. One of the benefits of a bedside ultrasound in the assessment of a patient with an initial diagnosis of severe sepsis or septic shock is the rapid diagnosis of cardiac tamponade if it is present. Data Source and Synthesis: A 55-year-old male presented to the emergency department with weakness, cough, and syncope. His examination was notable only for dusky mottling of his cheeks, chest, and neck. Specifically, there was no jugular venous distension or pulsus paradoxus. A chest radiograph showed a right upper lobe infiltrate, whereas his electrocardiogram showed only sinus tachycardia. His white blood cell count and lactic acid were elevated. The sepsis protocol was started and a bedside ultrasound revealed signs of cardiac tamponade. The patient immediately improved after a pericardiocentesis. Analysis of the pericardial biopsy revealed adenocarcinoma, later determined to be from a pulmonary primary source. Conclusions: Because low-pressure cardiac tamponade is life-threatening and difficult to diagnose, evaluation of the pericardium with a bedside ultrasound should be considered in patients with syncope, severe sepsis, or shock.

  17. Stress testing for risk stratification of patients with low to moderate probability of acute cardiac ischemia.

    Science.gov (United States)

    Chandra, A; Rudraiah, L; Zalenski, R J

    2001-02-01

    In summary, this article focused on the use of stress testing to risk-stratify patients at the conclusion of their emergency evaluation for ACI. As discussed, those patients in the probably not ACI category require additional risk stratification prior to discharge. It should be kept in mind that patients in this category are heterogeneous, containing subgroups at both higher and lower risk of ACI and cardiac events. The patients with lower pretest probability for ACI may only need exercise testing in the ED. Patients with higher pretest probability should undergo myocardial perfusion or echocardiographic stress testing to maximize diagnostic and prognostic information. Prognostic information is the key to provocative testing in the ED. Prognostic information is the component that will help emergency physicians identify the patients who may be discharged home safely without having to worry about a 6% annual cardiac death rate and a 10% overall death rate over the next 30 months. Stress testing provides this key prognostic data, and it can be obtained in short-stay chest pain observation units in a safe, timely, and cost-effective fashion. PMID:11214405

  18. A New Control Method to Reduce the Low-Frequency Output Current Ripple of AC-DC Converters by Using Virtual Inductor

    OpenAIRE

    Pekik Argo Dahono

    2012-01-01

    A new concept of virtual inductor to reduce the low-frequency dc output current ripple of ac-dc converters is introduced in this paper. Virtual inductor is defined as an additional control algorithm that changes the system behavior into the one that has an additional inductor connected on it. The virtual nature of the inductor makes the inductance can be designed without weight and volume restrictions. How to use the virtual inductor to improve the performance of converter current controller ...

  19. The Noise Performance of a Multiple-Input-Port and Multiple-Output-Port Low-Noise Amplifier Connected to an Array of Coupled Antennas

    OpenAIRE

    Evelyne Clavelier; Frédéric Broydé

    2011-01-01

    We address the noise characterization of a multiple-input-port and multiple-output-port (MIPMOP) device receiving signals from an array of antennas. A definition of the noise figures and natural noise figures of a MIPMOP device is provided, and the resulting properties are detailed in the impedance and admittance representations. We compute the natural noise figures of a low-noise MIPMOP amplifier comprising a MIMO series-series feedback amplifier (MIMO-SSFA), designed for a wireless receiver...

  20. EVALUACIÓN ECOCARDIOGRÁFICA DEL GASTO CARDÍACO SISTÉMICO EN LA ATRESIA PULMONAR CON SEPTO INTERVENTRICULAR INTACTO / Echocardiographic evaluation of cardiac output in pulmonary atresia with intact ventricular septum

    Directory of Open Access Journals (Sweden)

    Giselle Serrano Ricardo

    2013-07-01

    hemodynamic performance, influencing cardiac output and generating potential conditions for short-term prognosis. Method: A descriptive, prospective and applied study was conducted. It included 43 patients who were referred to the William Soler Pediatric Cardiology Hospital from January 1992 to November 2011 with a diagnosis of the disease. In each subject, the profiles of eight echocardiographic variables were assessed, as well as the heart rate profile. Their level of association and mutual dependence were statistically assessed by simple regression models. Results: There are considerable variations in heart rate, in the volume index and in the ejection fraction of the patients´ left ventricle compared with those in the reference control group. Conclusions: The increased size of the atrial septal defect and the prolongation of transmitral diastasis favor left ventricular volume increment. Heart rate, the restrictive nature of the left ventricular myocardium and its ejection fraction are regulatory factors of cardiac output in this disease.

  1. Output and error messages

    International Nuclear Information System (INIS)

    This document describes the output data and output files that are produced by the SYVAC A/C 1.03 computer program. It also covers the error messages generated by incorrect input data, and the run classification procedure. SYVAC A/C 1.03 simulates the groundwater mediated movement of radionuclides from underground facilities for the disposal of low and intermediate level wastes to the accessible environment, and provides an estimate of the subsequent radiological risk to man. (author)

  2. Efficacy and Safety of Low-Dose Everolimus as Maintenance Immunosuppression in Cardiac Transplant Recipients

    OpenAIRE

    Uwe Fuchs; Armin Zittermann; Uwe Schulz; Jan F Gummert

    2012-01-01

    For cardiac transplant (CTx) recipients, the recommended everolimus (EVL) dose is 0.75 mg bid or 1.5 mg bid and the target trough blood level is 3–8 μg/L. We studied a cohort of 56 CTx patients with chronic kidney disease receiving 0.75 mg bid EVL to maintain blood levels of 5–8 ug/L (designated RD group) and a cohort of 51 CTx patients with chronic kidney disease receiving 0.5 mg bid to maintain blood levels of 3–5 ug/L (designated LD group). The primary endpoint was a composite of death, re...

  3. Cardiac amyloidosis: a review and report of a new transthyretin (prealbumin) variant.

    OpenAIRE

    Hesse, A; Altland, K; Linke, R P; M.R. Almeida; Saraiva, M.J.; Steinmetz, A; Maisch, B

    1993-01-01

    Cardiac amyloidosis is caused by amyloid deposits derived from different human plasma proteins. It can lead to cardiac conduction disturbances, restrictive cardiomyopathy, and low output heart failure. The heart is variably involved during the development of systemic amyloidosis and seems to be more frequently affected in immunoglobulin (primary) than in reactive (secondary) amyloidosis. Amyloid is common in the elderly. Isolated atrial amyloid, for which a major subunit is the atrial natriur...

  4. In Vivo Measurement of Levofloxacin Penetration into Lung Tissue after Cardiac Surgery†

    OpenAIRE

    Hutschala, Doris; Skhirtladze, Keso; Zuckermann, Andreas; Wisser, Wilfried; Jaksch, Peter; Mayer-Helm, Bernhard Xaver; Burgmann, Heinz; Wolner, Ernst; Müller, Markus; Tschernko, Edda M.

    2005-01-01

    Nosocomial pneumonia is a severe complication after cardiac surgery (CS). Levofloxacin, a fluoroquinolone, qualifies for the therapy of postoperative pneumonia. However, penetration properties of levofloxacin into the lung tissue could be substantially affected by CS: atelectasis, low cardiac output after CS, high volume loads, and inflammatory capillary leak potentially influence drug distribution. The aim of our study was to gain information on interstitial antibiotic concentrations in lung...

  5. Estimación del gasto cardíaco: Utilidad en la práctica clínica. Monitorización disponible invasiva y no invasiva Estimating cardiac output: Utility in the clinical practice. Available invasive and non-invasive monitoring

    Directory of Open Access Journals (Sweden)

    X. García

    2011-12-01

    Full Text Available Esta revisión pretende profundizar en el conocimiento del gasto cardíaco, sus variables y sus condicionantes, así como repasar exhaustivamente las diferentes técnicas disponibles para su monitorización y establecer las situaciones en que el conocimiento del gasto cardíaco nos aporta una información fundamental en el manejo del paciente crítico. La técnica de Fick, utilizada en los inicios para calcular el gasto cardíaco de los pacientes, ha sido sustituida hoy en día en la práctica clínica por los métodos de termodilución (transcardíaca o transpulmonar, litiodilución, biorreactancia, la tecnología basada en el efecto Doppler o la ecocardiografía. El análisis de la onda de pulso ha permitido la obtención de una medida continua y mínimamente invasiva del gasto cardíaco. Otros métodos, como la biorrectancia, el Doppler o la ecocardiografía nos permiten, en la actualidad, obtener medidas del gasto cardíaco de forma no invasiva, rápida y fiable.This aim of this review is to provide a detailed review of the physiologic conditions and variables of the cardiac output, as well as review the different techniques available for its measurement. We also want to establish the clinical situations in which the measurement of cardiac output can add valuable information for the management of critically ill patients. The Fick technique, used in the beginning to calculate cardiac output, has been replaced today by thermodilution techniques (transcardiac or transpulmonary, lithium dilution, bioreactance, Doppler technique or echocardiography. Pulse wave analysis allows a continuous minimally invasive cardiac output measurement. Other methods, such bioreactance, Doppler technique or echocardiography currently provide a valid, fast and non-invasive measurement of cardiac output.

  6. New approach for simultaneous respiratory and cardiac motion correction in cardiac PET (NAMC-CPET)

    Science.gov (United States)

    Ahmed, Mohamed A. A.; Xiao, Peng; Xie, Qingguo

    2015-10-01

    Respiratory and cardiac motions are inevitable during the relatively long acquisition time of cardiac positron emission tomography (PET) scan. The correction of the resultant motion blur has become a significant challenge due to recent spatial resolution improvement of the PET scanners. The majority of current motion compensation algorithms are based on gating as a primary step. A new approach based on temporal basis functions is developed to correct respiratory and cardiac motion simultaneously in cardiac PET within the normal scanning time (NAMC-CPET). Simulation and experimental studies are conducted to evaluate and validate the final outputs in comparison to the existing gating methods. A dynamic digital phantom is used to simulate realistic human thorax and abdomen with respiratory and cardiac motions. GATE simulation was run at China National Grid Center to obtain realistic PET data in a reasonable time. Moreover, Tibet minipig experiments were conducted using a preclinical small animal PET scanner developed at HUST to validate the performance of the NAMC-CPET in real data. The results reveal that NAMC-CPET outperformed the existing gating methods (respiratory, cardiac, and dual) in cardiac imaging in term of noise reduction and contrast, especially in short acquisition duration. NAMC-CPET obtained better results in the conducted experiments in terms of contrast and the visibility of the heart. In contrast, the dual gating failed to obtain valuable images in the normal scan time due to the low 18F-FDG uptake. NAMC-CPET is advantageous in the low-statistic situation. The results are promising with great potential implications in cardiac PET imaging in terms of the radioactive dose and scan time reduction.

  7. New approach for simultaneous respiratory and cardiac motion correction in cardiac PET (NAMC-CPET)

    International Nuclear Information System (INIS)

    Respiratory and cardiac motions are inevitable during the relatively long acquisition time of cardiac positron emission tomography (PET) scan. The correction of the resultant motion blur has become a significant challenge due to recent spatial resolution improvement of the PET scanners. The majority of current motion compensation algorithms are based on gating as a primary step. A new approach based on temporal basis functions is developed to correct respiratory and cardiac motion simultaneously in cardiac PET within the normal scanning time (NAMC-CPET). Simulation and experimental studies are conducted to evaluate and validate the final outputs in comparison to the existing gating methods. A dynamic digital phantom is used to simulate realistic human thorax and abdomen with respiratory and cardiac motions. GATE simulation was run at China National Grid Center to obtain realistic PET data in a reasonable time. Moreover, Tibet minipig experiments were conducted using a preclinical small animal PET scanner developed at HUST to validate the performance of the NAMC-CPET in real data. The results reveal that NAMC-CPET outperformed the existing gating methods (respiratory, cardiac, and dual) in cardiac imaging in term of noise reduction and contrast, especially in short acquisition duration. NAMC-CPET obtained better results in the conducted experiments in terms of contrast and the visibility of the heart. In contrast, the dual gating failed to obtain valuable images in the normal scan time due to the low 18F-FDG uptake. NAMC-CPET is advantageous in the low-statistic situation. The results are promising with great potential implications in cardiac PET imaging in terms of the radioactive dose and scan time reduction. (paper)

  8. Interactions between breathing rate and low-frequency fluctuations in blood pressure and cardiac intervals.

    Science.gov (United States)

    Horsman, H M; Peebles, K C; Tzeng, Y C

    2015-10-01

    Evidence derived from spontaneous measures of cardiovagal baroreflex sensitivity (BRS) suggests that slow breathing at 6 breaths/min augments BRS. However, increases in BRS associated with slow breathing may simply reflect the frequency-dependent nature of the baroreflex rather than the modulation of baroreflex function by changes in breathing rate per se. To test this hypothesis we employed a crossover study design (n = 14) wherein breathing rate and systolic arterial blood pressure (SAP) oscillation induced via the application of oscillating lower body negative pressure (OLBNP) were independently varied at fixed frequencies. Breathing rate was controlled at 6 or 10 breaths/min with the aid of a metronome, and SAP oscillations were driven at 0.06 Hz and 0.1 Hz using OLBNP. The magnitudes of SAP and R-R interval (cardiac period) oscillations were quantified using power spectral analysis, and the transfer function gain between SAP and R-R interval was used to estimate BRS. Linear mixed-effects models were used to examine the main effects and interactions between breathing rate and OLBNP frequency. There was no statistical interaction between breathing and OLBNP frequency (P = 0.59), indicating that the effect of breathing rate on BRS did not differ according to OLBNP frequency (and vice versa). Additionally, there was no main effect for breathing rate (P = 0.28). However, we observed a significant main effect for OLBNP frequency (P = 0.01) consistent with the frequency-dependent nature of baroreflex. These findings suggest that increases in spectral indices of BRS reflect the frequency dependence of the baroreflex and are not due to slow breathing per se. PMID:26205543

  9. The Noise Performance of a Multiple-Input-Port and Multiple-Output-Port Low-Noise Amplifier Connected to an Array of Coupled Antennas

    Directory of Open Access Journals (Sweden)

    Frédéric Broydé

    2011-01-01

    Full Text Available We address the noise characterization of a multiple-input-port and multiple-output-port (MIPMOP device receiving signals from an array of antennas. A definition of the noise figures and natural noise figures of a MIPMOP device is provided, and the resulting properties are detailed in the impedance and admittance representations. We compute the natural noise figures of a low-noise MIPMOP amplifier comprising a MIMO series-series feedback amplifier (MIMO-SSFA, designed for a wireless receiver front-end.

  10. Stability Improvements in a Rail-to-Rail Input/Output, Constant Gm Operational Amplifier, at 0.4 V Operation, Using the Low-Voltage DTMOS Technique

    OpenAIRE

    Correia, Joana; Mancelos, Nuno; Goes, João

    2014-01-01

    The use of the dynamic threshold MOS (DTMOS) technique is evaluated in a two-stage rail-to-rail Input/Output, constant Gm amplifier. The proper choice of specific transistors in which the technique should be used is presented, as well as the resulting improvements, mainly regarding stability of the circuit at low voltage operation. The DTMOS technique is used in the NMOS transistors of the folded-cascode input stage, allowing the circuit to be stable at VDD = 0.4 V, with equivalent gain and g...

  11. Note: Light output enhanced fast response and low afterglow 6Li glass scintillator as potential down-scattered neutron diagnostics for inertial confinement fusion

    International Nuclear Information System (INIS)

    The characteristics of an APLF80+3Ce scintillator are presented. Its sufficiently fast decay profile, low afterglow, and an improved light output compared to the recently developed APLF80+3Pr, were experimentally demonstrated. This scintillator material holds promise for applications in neutron imaging diagnostics at the energy regions of 0.27 MeV of DD fusion down-scattered neutron peak at the world's largest inertial confinement fusion facilities such as the National Ignition Facility and the Laser Megajoule.

  12. Regulation of Cardiac Hypertrophy: the nuclear option

    NARCIS (Netherlands)

    D.W.D. Kuster (Diederik)

    2011-01-01

    textabstractCardiac hypertrophy is the response of the heart to an increased workload. After myocardial infarction (MI) the surviving muscle tissue has to work harder to maintain cardiac output. This sustained increase in workload leads to cardiac hypertrophy. Despite its apparent appropriateness, c

  13. Cardiac Cytochrome c Oxidase Activity and Contents of Submits 1 and 4 are Altered in Offspring by Low Prenatal Intake by Rat Dams

    Science.gov (United States)

    It has been reported previously that the offspring of rat dams consuming low dietary copper (Cu) during pregnancy and lactation experience a deficiency in cardiac cytochrome c oxidase (CCO) characterized by reduced catalytic activity and mitochondrial- and nuclear-subunit content after postnatal day...

  14. Influence of high- and low-LET radiation on the cardiac differentiation of mouse embryonic stem cells

    Energy Technology Data Exchange (ETDEWEB)

    Helm, Alexander

    2013-07-19

    The in utero exposure to ionising radiation poses a risk for the radiosensitive developing embryo. Effects of low-LET radiation on different developmental stages of the embryo are relatively well known due to experimental studies and epidemiological data. Data for effects on the very early stage of the embryonic development, particularly the effects of high-LET radiation instead are rather limited. However, unanticipated exposures of the early embryo to ionising radiation may occur through diagnostic or therapeutic applications or through radiation accidents. Additionally, protons and carbon ions are increasingly used in radiotherapy. Thus, a risk estimation of high-LET exposure especially to the early embryo is of a certain importance. To address this topic, pluripotent mouse embryonic stem cells resembling the blastocyst stage were irradiated with high-LET carbon ions or low-LET X-rays and subsequently differentiated to mimic the early embryonic development. The occurrence of spontaneously contracting cardiomyocytes was used as a marker to asses the radiation effects on the differentiation. Among others, cell inactivation, cell death and gene expression were analysed. A delay in the cardiac differentiation after radiation exposure was found. The results point to radiation-induced cell killing as the main effector of the developmental delay. Carbon ions were found to be more effective than X-rays.

  15. Influence of high- and low-LET radiation on the cardiac differentiation of mouse embryonic stem cells

    International Nuclear Information System (INIS)

    The in utero exposure to ionising radiation poses a risk for the radiosensitive developing embryo. Effects of low-LET radiation on different developmental stages of the embryo are relatively well known due to experimental studies and epidemiological data. Data for effects on the very early stage of the embryonic development, particularly the effects of high-LET radiation instead are rather limited. However, unanticipated exposures of the early embryo to ionising radiation may occur through diagnostic or therapeutic applications or through radiation accidents. Additionally, protons and carbon ions are increasingly used in radiotherapy. Thus, a risk estimation of high-LET exposure especially to the early embryo is of a certain importance. To address this topic, pluripotent mouse embryonic stem cells resembling the blastocyst stage were irradiated with high-LET carbon ions or low-LET X-rays and subsequently differentiated to mimic the early embryonic development. The occurrence of spontaneously contracting cardiomyocytes was used as a marker to asses the radiation effects on the differentiation. Among others, cell inactivation, cell death and gene expression were analysed. A delay in the cardiac differentiation after radiation exposure was found. The results point to radiation-induced cell killing as the main effector of the developmental delay. Carbon ions were found to be more effective than X-rays.

  16. Transfusion of blood during cardiac surgery is associated with higher long-term mortality in low-risk patients

    DEFF Research Database (Denmark)

    Jakobsen, Carl-Johan; Ryhammer, Pia Katarina; Jensen, Mariann Tang; Andreasen, Jan Jesper; Mortensen, Poul Erik

    2012-01-01

    Numerous reports have emphasized the need for reduction in transfusions of allogeneic red blood cells (RBC) due to increased morbidity and mortality. Nevertheless, transfusion rates are still high in several cardiac surgery institutions. Reports on long-term survival after cardiac surgery and RBC...... transfusion are few....

  17. Low carbohydrate/high-fat diet attenuates cardiac hypertrophy, remodeling, and altered gene expression in hypertension

    Science.gov (United States)

    The effects of dietary fat intake on the development of left ventricular hypertrophy and accompanying structural and molecular remodeling in response to hypertension are not understood. The present study compared the effects of a high-fat versus a low-fat diet on development of left ventricular hype...

  18. Stimulating endogenous cardiac regeneration

    Directory of Open Access Journals (Sweden)

    Amanda eFinan

    2015-09-01

    Full Text Available 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 couldameliorate the overall repair process to incorporate the participation ofmultiple cell players.

  19. Regulation of Cardiac Hypertrophy: the nuclear option

    OpenAIRE

    Kuster, Diederik

    2011-01-01

    textabstractCardiac hypertrophy is the response of the heart to an increased workload. After myocardial infarction (MI) the surviving muscle tissue has to work harder to maintain cardiac output. This sustained increase in workload leads to cardiac hypertrophy. Despite its apparent appropriateness, cardiac hypertrophy is an independent risk factor for the development of heart failure and is therefore called pathological hypertrophy. That hypertrophy is not bad per se, is illustrated by the hyp...

  20. Remote detection of mental workload changes using cardiac parameters assessed with a low-cost webcam.

    Science.gov (United States)

    Bousefsaf, Frédéric; 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

  1. Highly accelerated cardiac cine parallel MRI using low-rank matrix completion and partial separability model

    Science.gov (United States)

    Lyu, Jingyuan; Nakarmi, Ukash; Zhang, Chaoyi; Ying, Leslie

    2016-05-01

    This paper presents a new approach to highly accelerated dynamic parallel MRI using low rank matrix completion, partial separability (PS) model. In data acquisition, k-space data is moderately randomly undersampled at the center kspace navigator locations, but highly undersampled at the outer k-space for each temporal frame. In reconstruction, the navigator data is reconstructed from undersampled data using structured low-rank matrix completion. After all the unacquired navigator data is estimated, the partial separable model is used to obtain partial k-t data. Then the parallel imaging method is used to acquire the entire dynamic image series from highly undersampled data. The proposed method has shown to achieve high quality reconstructions with reduction factors up to 31, and temporal resolution of 29ms, when the conventional PS method fails.

  2. C- Reactive protein, cardiac troponin T and low albumin are predictors of mortality in hemodialysis patients

    OpenAIRE

    Bagheri Nazila; Taziki Omolbanin; Falaknazi Kianoosh

    2009-01-01

    Overall and cardiovascular mortality are significantly higher in hemodialysis patients with elevated C-reactive protein (CRP). The aim of study was to determine whether CRP, low albumin and troponin are markers of overall and cardiovascular mortality in hemodialysis patients. 138 stable hemodialysis patients were divided into 2 groups n= 66 patients with coronary disease equivalent (known coronary or peripheral vascular disease or diabetes mellitus) and n= 72 patients without it. The two grou...

  3. Application of pulse index continuous cardiac output monitoring to improve efficiency of acute heart failure care%应用脉搏指数连续心输出量监测提升急性心力衰竭护理效果

    Institute of Scientific and Technical Information of China (English)

    孙秀月; 张领; 赵书琴

    2015-01-01

    Objective To ihvestigate the effect of pulse index continuous cardiac output (PiCCO) monitoring to nursing care of acute heart failure care.Methods The clinical data of 43 acute heart failure patients were retrospectively analyzed,patients were given pulse index continuous cardiac output monitoring and care,the patient' s nursing outcomes were observed,and the intrathoracic blood volume,cardiac output and oxygen consumption before and after the intervention were compared.Results After the implementation of PiCCO and nursing intervention,43 patients had no serious complications,improved 42 cases discharged,the other 1 patient in critical condition due to old age and heart function improvement sustained no automatic discharge.Oxygen consumption,cardiac output and intrathoracic blood volume were improved after the intervention,there was a significant difference (P < 0.05) compared to the previous indicators and intervention after intervention.Conclusions Application of pulse index continuous cardiac output can effectively improve patient's clinical parameters such as cardiac output,through the implementation of appropriate care can improve symptoms and reduce complications.%目的 探讨急性心力衰竭患者护理中应用脉搏指数连续心输出量监测(PiCCO)的效果.方法 选取平顶山市第二人民医院收治的43例急性心力衰竭患者作为研究对象,收集患者的临床资料并对其做回顾性分析,对患者实施脉搏指数连续心输出量监测和护理,对患者的护理效果进行观察,并对其干预前后的胸腔内血容量、心排血量与氧耗量进行对比观察.结果 实施PiCCO和护理干预,本研究43例患者均无严重并发症产生,42例好转出院,1例由于病情危重、高龄及心功能持续无改善自动出院.患者干预后的氧耗量、心排血量与胸腔内血容量均有所改善,干预后各项指标与干预前比较差异有统计学意义(P<0.05).结论 应用脉搏指数连续心

  4. Indirect calorimetry can be used to measure cardiac output in septic patients? A calorimetria indireta pode ser utilizada para medir o débito cardíaco em pacientes sépticos?

    Directory of Open Access Journals (Sweden)

    Maria Auxiliadora Martins

    2008-01-01

    Full Text Available PURPOSE: The aim of this study was to compare two different cardiac output (CO monitoring systems based on the thermodilution principle (Thermo-CO and indirect calorimetry (Fick mixed-CO in septic patients. METHODS: Prospective study in septic patients admitted in an intensive care unit of a university hospital. Nineteen patients aged on average 45.4 ± 21.5 years were enrolled in the study. Four series of hourly measurements by the two techniques were carried out simultaneously. RESULTS: No significant differences were observed between Thermo-CO and Fick mixed-CO (7.0 ± 1.8 L.min-1 and 6.4 ± 1.7 L.min-1.. Parallel analysis of Fick mixed-CO and Fick atrial-CO was performed introducing a correction factor for the eight atrial samples in order to adjust the values of oxygen saturation obtained from atrial blood (Fick corrected atrial-CO to those obtained from mixed venous blood. No significant differences could be detected between Fick mixed-CO and Fick corrected atrial-CO. The correlation coefficients of Thermo CO/Fick mixed-CO and Fick mixed-CO/Fick corrected atrial-CO were 0.84 and 0.94, respectively. CONCLUSION: We observed that the agreement between the two methods was satisfactory on the basis of the decisions made for treatment. Indirect calorimetry is useful to measure CO in patients with septic shock.OBJETIVO: O objetivo deste estudo foi comparar as medidas do débito cardíaco (DC obtidas pela termodiluição (DC-termo e pela calorimetria indireta (DC-Fick misto em pacientes com choque séptico. MÉTODOS: Estudo prospectivo em pacientes sépticos internados em unidade de terapia intensiva de um hospital universitário. Foram estudados 19 pacientes (45,4 ± 21,5 anos. Foram realizadas quatro séries de medidas do DC pelos dois métodos, simultaneamente. RESULTADOS: Não houve diferenças significativas entre os valores do DC-termo e DC-Fick misto (7,0 ± 1,8 L.min-1 e 6,4 ± 1,7 L.min-1, respectivamente. Na avaliação dos oito casos

  5. Coronary calcium score in 12-year breast cancer survivors after adjuvant radiotherapy with low to moderate heart exposure – Relationship to cardiac radiation dose and cardiovascular risk factors

    International Nuclear Information System (INIS)

    Background/purpose: We explored the relation between coronary artery calcium (CAC) and cardiac radiation doses in breast cancer survivors (BCS) treated with radiotherapy (RT). Additionally, we examined the impact of other risk factors and biomarkers of coronary artery disease (CAD). Materials and methods: 236 BCS (median age 51 years [range 30–70], median observation time 12 years [9.2–15.7]), treated with 4-field RT of 50GY, were included and examined in 2004 (T1), 2007 (T2) and 2011 (T3) with clinical examination, blood tests and questionnaires. At T3, cardiac computed tomography was performed with quantification of CAC using Agatston score (AS). For 106 patients cardiac dose volume histograms were available. Results: The cohort-based median of the mean cardiac dose was 2.5 (range 0.5–7.0) Gy. There was no correlation between measures of cardiac dose and AS. AS was correlated with high cholesterol at T1/T2 (p = 0.022), high proBNP at T1/T2 (p < 0.022) and T3 (p < 0.022) and high HbA1c at T3 (p = 0.022). In addition, a high AS was significantly associated with hypertension (p = 0.022). Age (p < 0.001) and cholesterol at T1/T2 (p = 0.001) retained significant associations in multivariate analysis. Conclusions: Traditional, modifiable risk factors of CAD correlate with CAC and may be important for the long term risk of CAD after RT. With low to moderate cardiac radiation exposure, a contribution of radiation dose to CAC could not be demonstrated

  6. Positive Inotropic Effects of Low dATP/ATP Ratios on Mechanics and Kinetics of Porcine Cardiac Muscle

    OpenAIRE

    Schoffstall, Brenda; Clark, Amanda; Chase, P. Bryant

    2006-01-01

    Substitution of 2′-deoxy ATP (dATP) for ATP as substrate for actomyosin results in significant enhancement of in vitro parameters of cardiac contraction. To determine the minimal ratio of dATP/ATP (constant total NTP) that significantly enhances cardiac contractility and obtain greater understanding of how dATP substitution results in contractile enhancement, we varied dATP/ATP ratio in porcine cardiac muscle preparations. At maximum Ca2+ (pCa 4.5), isometric force increased linearly with dAT...

  7. Ventilation and gas exchange management after cardiac arrest.

    Science.gov (United States)

    Sutherasan, Yuda; Raimondo, Pasquale; Pelosi, Paolo

    2015-12-01

    For several decades, physicians had integrated several interventions aiming to improve the outcomes in post-cardiac arrest patients. However, the mortality rate after cardiac arrest is still as high as 50%. Post-cardiac arrest syndrome is associated with high morbidity and mortality due to not only poor neurological outcome and cardiovascular failure but also respiratory dysfunction. To minimize ventilator-associated lung injury, protective mechanical ventilation by using low tidal volume ventilation and driving pressure may decrease pulmonary complications and improve survival. Low level of positive end-expiratory pressure (PEEP) can be initiated and titrated with careful cardiac output and respiratory mechanics monitoring. Furthermore, optimizing gas exchange by avoiding hypoxia and hyperoxia as well as maintaining normocarbia may improve neurological and survival outcome. Early multidisciplinary cardiac rehabilitation intervention is recommended. Minimally invasive monitoring techniques, that is, echocardiography, transpulmonary thermodilution method measuring extravascular lung water, as well as transcranial Doppler ultrasound, might be useful to improve appropriate management of post-cardiac arrest patients. PMID:26670813

  8. Heart rate variability at limiting stationarity: evidence of neuro-cardiac control mechanisms operating at ultra-low frequencies

    International Nuclear Information System (INIS)

    This study considers the linkage of exogenously stimulated emotional stress with the neurogenic regulation of heart rate operating at very low frequencies. The objectives were three-fold: to consider the present evidence that such a linkage exists as a primary phenomenon; to compare the potential of a frequency-domain method and a time-domain method in revealing this phenomenon by characterizing heart rate variability (HRV) at frequencies of [0.0005…0.4] Hz and to design, implement and report a physiological experiment in which alternating periods of exposure to bland and high valence visual stimuli might reveal this phenomenon. A methodical challenge was to optimize the length of exposure to the stimulus such that subjects did not have time to habituate to stimuli, whilst acquiring sufficient data (heart beats) such that the ultra-low frequency (ULF) components of HRV could be described. With exposure times set to approximately 5 min, during which time the strength of the stimulus and the corresponding evoked response were considered stationary, the lowest HRV frequency component that could be characterized was 0.003 Hz. In trials with parametrically defined test data, the time-domain method based on the Ornstein–Uhlenbeck Gaussian process (OU-GP) was shown to be better than the frequency-domain method in describing the ULF components of the HRV. In an experimental cohort of 16 subjects, analysis using the OU-GP revealed evidence of cardiac regulatory mechanisms influenced by emotional valence operating in the bandwidth (ULF*) [0.002…0.01] Hz. (paper)

  9. Low radiation dose non-contrast cardiac CT: is it of value in the evaluation of mechanical aortic valve

    International Nuclear Information System (INIS)

    Background: Prosthetic bileaflet mechanical valve function has been traditionally evaluated using echocardiography and fluoroscopy. Multidetector computed tomography (MDCT) is a novel technique for cardiac evaluation. Purpose: To evaluate bileaflet mechanical aortic valves using a low-milliampere (mA), non-contrast MDCT protocol with a limited scan range. Material and Methods: Forty patients with a bileaflet mechanical aortic valve were evaluated using a non-contrast, low-mA, ECG-gated 64 MDCT protocol with a limited scan range. MDCT findings of opening and closing valve angles were correlated to fluoroscopy and echocardiography. Also, the valve visibility was evaluated on MDCT and fluoroscopy according to a 3-point grading scale. Results: The visualization score with the MDCT was significantly superior to the fluoroscopy (3 vs. 2.7). A strong correlation was noted between the opening (r = 0.82) and closing (r = 0.96) valve angles with MDCT and fluoroscopy without a statistically significant difference (P = 0.31 and 0.16, respectively). The mean effective radiation dose of the suggested protocol was 4 ± 0.5 mSv. Five valves were evaluated using transesophageal echocardiography because the valves were difficult to evaluate with transthoracic echocardiography, and all of these valves were evaluated optimally with MDCT. A high-pressure gradient was noted in nine valves, and the MDCT showed that seven of these valves inadequately opened, and two valves opened well, which resulted in patient valve mismatch. Incomplete valve closure was noted in five valves, and the echocardiography showed significant transvalvular regurgitation in all five valves. Conclusion: MDCT can provide a precise measurement of valve function and can potentially evaluate high-pressure gradients and transvalvular regurgitation

  10. Impact of increasing levels of advanced iterative reconstruction on image quality in low-dose cardiac CT angiography

    International Nuclear Information System (INIS)

    Purpose: To investigate the effects of an advanced iterative reconstruction (IR) technique on subjective and objective image quality (IQ) in low-dose cardiac CT angiography (CCTA). Materials and Methods: 30 datasets of prospectively triggered 'step-and-shoot' CCTA scans acquired on a 256-slice CT scanner with optimized exposure settings were processed on a prototype IR system using filtered back-projection (FBP) and 4 levels of advanced IR (iDose4, Philips) providing incremental rates of IR (level 2, 4, 6, 7). In addition, the effects of different reconstruction kernels (semi-smooth [CB], standard with edge-enhancement [XCB]) and a 'multi-resolution' feature [MR] to preserve the noise power spectrum were evaluated resulting in a total of n = 480 image sets. Contrast-to-noise ratios (CNR) were computed from regions of interest at 9 coronary locations. The subjective IQ was rated on a 4-point-scale with 'classic' image appearance and noise-related artifacts as main criteria. Results: At an effective dose of 1.7 ± 0.7 mSv, the CNR significantly improved with every increasing level of IR (range: 14.2-27.8; p < 0.001) with the best objective IQ at the highest level of IR (level 7). The subjective IQ, however, was rated best at the medium level of IR (level 4) with minimal artifacts and a more 'classic' image appearance when compared to higher IR levels. The XCB kernel provided better subjective ratings than CB (p < 0.05) and the MR feature further increased the IQ at a high level of IR. Conclusion: The objective IQ of low-dose CCTA progressively improves with an increasing level of IR. The best subjective IQ, however, is reached at medium levels of IR combined with an edge-enhancing kernel allowing for preservation of a 'classic' image appearance suggesting application in the clinical routine. (orig.)

  11. Low-dose radiation affects cardiac physiology: gene networks and molecular signaling in cardiomyocytes.

    Science.gov (United States)

    Coleman, Matthew A; Sasi, Sharath P; Onufrak, Jillian; Natarajan, Mohan; Manickam, Krishnan; Schwab, John; Muralidharan, Sujatha; Peterson, Leif E; Alekseyev, Yuriy O; Yan, Xinhua; Goukassian, David A

    2015-12-01

    There are 160,000 cancer patients worldwide treated with particle radiotherapy (RT). With the advent of proton, and high (H) charge (Z) and energy (E) HZE ionizing particle RT, the cardiovascular diseases risk estimates are uncertain. In addition, future deep space exploratory-type missions will expose humans to unknown but low doses of particle irradiation (IR). We examined molecular responses using transcriptome profiling in left ventricular murine cardiomyocytes isolated from mice that were exposed to 90 cGy, 1 GeV proton ((1)H) and 15 cGy, 1 GeV/nucleon iron ((56)Fe) over 28 days after exposure. Unsupervised clustering analysis of gene expression segregated samples according to the IR response and time after exposure, with (56)Fe-IR showing the greatest level of gene modulation. (1)H-IR showed little differential transcript modulation. Network analysis categorized the major differentially expressed genes into cell cycle, oxidative responses, and transcriptional regulation functional groups. Transcriptional networks identified key nodes regulating expression. Validation of the signal transduction network by protein analysis and gel shift assay showed that particle IR clearly regulates a long-lived signaling mechanism for ERK1/2, p38 MAPK signaling and identified NFATc4, GATA4, STAT3, and NF-κB as regulators of the response at specific time points. These data suggest that the molecular responses and gene expression to (56)Fe-IR in cardiomyocytes are unique and long-lasting. Our study may have significant implications for the efforts of National Aeronautics and Space Administration to develop heart disease risk estimates for astronauts and for patients receiving conventional and particle RT via identification of specific HZE-IR molecular markers. PMID:26408534

  12. Low-dose interpolated average CT for attenuation correction in cardiac PET/CT

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Tung-Hsin [Department of Biomedical Imaging and Radiological Sciences, National Yang Ming University, Taiwan (China); Zhang, Geoffrey [Department of Radiation Oncology, Moffitt Cancer Center, Florida (United States); Wang, Shyh-Jen [Department of Biomedical Imaging and Radiological Sciences, National Yang Ming University, Taiwan (China); Department of Nuclear Medicine, Taipei Veterans General Hospital, Taiwan (China); Chen, Chih-Hao [Department of Nuclear Medicine, Taipei Veterans General Hospital, Taiwan (China); Yang, Bang-Hung [Department of Biomedical Imaging and Radiological Sciences, National Yang Ming University, Taiwan (China); Department of Nuclear Medicine, Taipei Veterans General Hospital, Taiwan (China); Wu, Nien-Yun [Department of Nuclear Medicine, Taipei Veterans General Hospital, Taiwan (China); Huang, Tzung-Chi, E-mail: tzungchi.huang@mail.cmu.edu.t [Department of Biomedical Imaging and Radiological Science, China Medical University, Taiwan (China)

    2010-07-21

    Because of the advantages in the use of high photon flux and thus the short scan times of CT imaging, the traditional {sup 68}Ge scans for positron emission tomography (PET) image attenuation correction have been replaced by CT scans in the modern PET/CT technology. The combination of fast CT scan and slow PET scan often causes image misalignment between the PET and CT images due to respiration motion. Use of the average CT derived from cine CT images is reported to reduce such misalignment. However, the radiation dose to patients is higher with cine CT scans. This study introduces a method that uses breath-hold CT images and their interpolations to generate the average CT for PET image attenuation correction. Breath-hold CT sets are taken at end-inspiration and end-expiration. Deformable image registration is applied to generate a voxel-to-voxel motion matrix between the two CT sets. The motion is equally divided into 5 steps from inspiration to expiration and 5 steps from expiration to inspiration, generating a total of 8 phases of interpolated CT sets. An average CT image is generated from all the 10 phase CT images, including original inhale/exhale CT and 8 interpolated CT sets. Quantitative comparison shows that the reduction of image misalignment artifacts using the average CT from the interpolation technique for PET attenuation correction is at a similar level as that using cine average CT, while the dose to the patient from the CT scans is reduced significantly. The interpolated average CT method hence provides a low dose alternative to cine CT scans for PET attenuation correction.

  13. Low-dose interpolated average CT for attenuation correction in cardiac PET/CT

    International Nuclear Information System (INIS)

    Because of the advantages in the use of high photon flux and thus the short scan times of CT imaging, the traditional 68Ge scans for positron emission tomography (PET) image attenuation correction have been replaced by CT scans in the modern PET/CT technology. The combination of fast CT scan and slow PET scan often causes image misalignment between the PET and CT images due to respiration motion. Use of the average CT derived from cine CT images is reported to reduce such misalignment. However, the radiation dose to patients is higher with cine CT scans. This study introduces a method that uses breath-hold CT images and their interpolations to generate the average CT for PET image attenuation correction. Breath-hold CT sets are taken at end-inspiration and end-expiration. Deformable image registration is applied to generate a voxel-to-voxel motion matrix between the two CT sets. The motion is equally divided into 5 steps from inspiration to expiration and 5 steps from expiration to inspiration, generating a total of 8 phases of interpolated CT sets. An average CT image is generated from all the 10 phase CT images, including original inhale/exhale CT and 8 interpolated CT sets. Quantitative comparison shows that the reduction of image misalignment artifacts using the average CT from the interpolation technique for PET attenuation correction is at a similar level as that using cine average CT, while the dose to the patient from the CT scans is reduced significantly. The interpolated average CT method hence provides a low dose alternative to cine CT scans for PET attenuation correction.

  14. Low-dose interpolated average CT for attenuation correction in cardiac PET/CT

    Science.gov (United States)

    Wu, Tung-Hsin; Zhang, Geoffrey; Wang, Shyh-Jen; Chen, Chih-Hao; Yang, Bang-Hung; Wu, Nien-Yun; Huang, Tzung-Chi

    2010-07-01

    Because of the advantages in the use of high photon flux and thus the short scan times of CT imaging, the traditional 68Ge scans for positron emission tomography (PET) image attenuation correction have been replaced by CT scans in the modern PET/CT technology. The combination of fast CT scan and slow PET scan often causes image misalignment between the PET and CT images due to respiration motion. Use of the average CT derived from cine CT images is reported to reduce such misalignment. However, the radiation dose to patients is higher with cine CT scans. This study introduces a method that uses breath-hold CT images and their interpolations to generate the average CT for PET image attenuation correction. Breath-hold CT sets are taken at end-inspiration and end-expiration. Deformable image registration is applied to generate a voxel-to-voxel motion matrix between the two CT sets. The motion is equally divided into 5 steps from inspiration to expiration and 5 steps from expiration to inspiration, generating a total of 8 phases of interpolated CT sets. An average CT image is generated from all the 10 phase CT images, including original inhale/exhale CT and 8 interpolated CT sets. Quantitative comparison shows that the reduction of image misalignment artifacts using the average CT from the interpolation technique for PET attenuation correction is at a similar level as that using cine average CT, while the dose to the patient from the CT scans is reduced significantly. The interpolated average CT method hence provides a low dose alternative to cine CT scans for PET attenuation correction.

  15. Low-Power CMOS VCO with Dual-Band Local Oscillating Signal Outputs for 5/2.5-GHz WLAN Transceivers

    Institute of Scientific and Technical Information of China (English)

    池保勇; 石秉学

    2003-01-01

    The paper describes a novel low-power CMOS voltage-controlled oscillator (VCO) with dual-band local oscillating (LO) signal outputs for 5/2.5-GHz wireless local area network (WLAN) transceivers. The VCO is based on an on-chip symmetrical spiral inductor and a differential varactor. The 2.5-GHz quadrature LO signals are generated using the injection-locked frequency divider (ILFD) technique. The ILFD structure is similar to the VCO structure with its wide tracking range. The design tool ASITIC was used to optimize all on-chip symmetrical inductors. The power consumption was kept low with differential LC tanks and the ILFD technique. The circuit was implemented in a 0.18-μm CMOS process. Hspice and SpectreRF simulations show the proposed circuit could generate low phase noise 5/2.5-GHz dual band LO signals with a wide tuning range. The 2.5-GHz LO signals are quadrature with almost no phase and amplitude errors. The circuit consumes less than 5.3 mW in the tuning range with a power supply voltage of 1.5 V. The die area is only 1.0 mm×1.0 mm.

  16. External cardiac compression may be harmful in some scenarios of pulseless electrical activity.

    LENUS (Irish Health Repository)

    Hogan, T S

    2012-10-01

    Pulseless electrical activity occurs when organised or semi-organised electrical activity of the heart persists but the product of systemic vascular resistance and the increase in systemic arterial flow generated by the ejection of the left venticular stroke volume is not sufficient to produce a clinically detectable pulse. Pulseless electrical activity encompasses a very heterogeneous variety of severe circulatory shock states ranging in severity from pseudo-cardiac arrest to effective cardiac arrest. Outcomes of cardiopulmonary resuscitation for pulseless electrical activity are generally poor. Impairment of cardiac filling is the limiting factor to cardiac output in many scenarios of pulseless electrical activity, including extreme vasodilatory shock states. There is no evidence that external cardiac compression can increase cardiac output when impaired cardiac filling is the limiting factor to cardiac output. If impaired cardiac filling is the limiting factor to cardiac output and the heart is effectively ejecting all the blood returning to it, then external cardiac compression can only increase cardiac output if it increases venous return and cardiac filling. Repeated cardiac compression asynchronous with the patient\\'s cardiac cycle and raised mean intrathoracic pressure due to chest compression can be expected to reduce rather than to increase cardiac filling and therefore to reduce rather than to increase cardiac output in such circumstances. The hypothesis is proposed that the performance of external cardiac compression will have zero or negative effect on cardiac output in pulseless electrical activity when impaired cardiac filling is the limiting factor to cardiac output. External cardiac compression may be both directly and indirectly harmful to significant sub-groups of patients with pulseless electrical activity. We have neither evidence nor theory to provide comfort that external cardiac compression is not harmful in many scenarios of pulseless

  17. Amelioration of Cardiac Function and Activation of Anti-Inflammatory Vasoactive Peptides Expression in the Rat Myocardium by Low Level Laser Therapy

    OpenAIRE

    Manchini, Martha Trindade; Serra, Andrey Jorge; Feliciano, Regiane dos Santos; Santana, Eduardo Tadeu; Antônio, Ednei Luis; de Tarso Camillo de Carvalho, Paulo; Montemor, Jairo; Crajoinas, Renato Oliveira; Girardi, Adriana Castello Costa; Tucci, Paulo José Ferreira; Silva, José Antônio

    2014-01-01

    Low-level laser therapy (LLLT) has been used as an anti-inflammatory treatment in several disease conditions, even when inflammation is a secondary consequence, such as in myocardial infarction (MI). However, the mechanism by which LLLT is able to protect the remaining myocardium remains unclear. The present study tested the hypothesis that LLLT reduces inflammation after acute MI in female rats and ameliorates cardiac function. The potential participation of the Renin-Angiotensin System (RAS...

  18. Development of Amorphous/Microcrystalline Silicon Tandem Thin-Film Solar Modules with Low Output Voltage, High Energy Yield, Low Light-Induced Degradation, and High Damp-Heat Reliability

    Directory of Open Access Journals (Sweden)

    Chin-Yi Tsai

    2014-01-01

    Full Text Available In this work, tandem amorphous/microcrystalline silicon thin-film solar modules with low output voltage, high energy yield, low light-induced degradation, and high damp-heat reliability were successfully designed and developed. Several key technologies of passivation, transparent-conducting-oxide films, and cell and segment laser scribing were researched, developed, and introduced into the production line to enhance the performance of these low-voltage modules. A 900 kWp photovoltaic system with these low-voltage panels was installed and its performance ratio has been simulated and projected to be 92.1%, which is 20% more than the crystalline silicon and CdTe counterparts.

  19. Cardiac tumors: leiomyosarcoma – a case report

    Science.gov (United States)

    Syska-Sumińska, Joanna; Zieliński, Piotr; Dłużniewski, Mirosław; Sadowski, Jerzy

    2015-01-01

    We present a case report of a 60-year-old woman with a long history of leiomyosarcoma in different locations. She was admitted to the clinic due to a left ventricular tumor diagnosed in ECHO examination. The patient was qualified for radical tumor resection. The early postoperative period was complicated due to low cardiac output syndrome and bradyarrhythmia requiring temporary cardiac pacing. Optimized pharmacological therapy resulted in a gradual reduction of symptoms and a clinical improvement of congestive heart failure (NYHA III – NYHA II). Due to the radical nature of the surgery, the patient was not referred for supplementary treatment. The follow-up currently exceeds 12 months – no new metastases have been found. This case provides an example of how to diagnose and treat heart tumors. PMID:26702284

  20. Quantification of left and right ventricular function and myocardial mass: Comparison of low-radiation dose 2nd generation dual-source CT and cardiac MRI

    International Nuclear Information System (INIS)

    Objective: To prospectively evaluate the accuracy of left and right ventricular function and myocardial mass measurements based on a dual-step, low radiation dose protocol with prospectively ECG-triggered 2nd generation dual-source CT (DSCT), using cardiac MRI (cMRI) as the reference standard. Materials and methods: Twenty patients underwent 1.5 T cMRI and prospectively ECG-triggered dual-step pulsing cardiac DSCT. This image acquisition mode performs low-radiation (20% tube current) imaging over the majority of the cardiac cycle and applies full radiation only during a single adjustable phase. Full-radiation-phase images were used to assess cardiac morphology, while low-radiation-phase images were used to measure left and right ventricular function and mass. Quantitative CT measurements based on contiguous multiphase short-axis reconstructions from the axial CT data were compared with short-axis SSFP cardiac cine MRI. Contours were manually traced around the ventricular borders for calculation of left and right ventricular end-diastolic volume, end-systolic volume, stroke volume, ejection fraction and myocardial mass for both modalities. Statistical methods included independent t-tests, the Mann–Whitney U test, Pearson correlation statistics, and Bland–Altman analysis. Results: All CT measurements of left and right ventricular function and mass correlated well with those from cMRI: for left/right end-diastolic volume r = 0.885/0.801, left/right end-systolic volume r = 0.947/0.879, left/right stroke volume r = 0.620/0.697, left/right ejection fraction r = 0.869/0.751, and left/right myocardial mass r = 0.959/0.702. Mean radiation dose was 6.2 ± 1.8 mSv. Conclusions: Prospectively ECG-triggered, dual-step pulsing cardiac DSCT accurately quantifies left and right ventricular function and myocardial mass in comparison with cMRI with substantially lower radiation exposure than reported for traditional retrospective ECG-gating.

  1. Application of cardiac output measurement by bioelectrical impedance in critically ill patients%生物电阻抗法监测心输出量在危重病中的应用

    Institute of Scientific and Technical Information of China (English)

    刘紫锰; 杨春华; 陈娟; 欧阳彬; 管向东

    2009-01-01

    目的 探讨生物电阻抗法测量无创心输出量(CO)在危重病中应用的准确性和有效性.方法 选择2008年1月至5月间本院外科重症监护中心(SICU)收治的12例需放置SWAN-GANZ导管进行血流动力学监测的患者,同时用生物电阻抗法和SWAN-GANZ导管热稀释法测定患者CO曲线平稳后0、1、6、12、24、48 h的CO值,并应用Pearson相关对两种方法测得的CO值与时间进行分析.结果 生物电阻抗法测最的CO值在所有时间点均低于SWAN-GANZ导管热稀释法的测最值[0 h:(5.5±0.9)L/min比(7.7±1.4)L/min;1h:(5.3±0.7)L/min比(7.4±1.5)L/min;6 h:(4.6±0.6)L/min比(6.8±1.4)L/min;12 h:(5.1±0.9)L/min比(7.6±1.6)L/min;24 h:(6.1±1.1)L/min比(9.0±1.6)L/min;48 h:(6.3±1.3)L/min比(9.5±1.5)L/min;均P<0.05].两种方法测量的CO值均随着时间的延长而呈升高趋势(r=0.818,P=0.047和r=0.884,P=0.020).结论 生物电阻抗法测量的无创CO与SWAN-GANZ导管测定的患者CO同样呈时间依赖性,是一种有效的CO监测方法.%Objective To evaluate the efficacy and accuracy of non-invasive bioelectrical impedance measurement of cardiac output (CO) in critically ill patients. Methods Between January and May 2008, 12 patients who needed hemodynamics monitoring using SWAN-GANZ catheterization in surgical intensive care unit (SICU) of our hospital were measured for CO by bioelectrical impedance and SWAN-GANZ catheterization thermodilution approaches. These values were recorded at 0, 1, 6, 12, 24 and 48 hours after the CO curve became stable in these patients. Pearson correlation analysis was performed for CO values over time recorded by these two approaches. Results At all the time points, CO measurement by bioelectrical impedance yielded lower values than those by SWAN-GANZ catheterization thermodilution approach [0 h: (5.5±0.9) L/min vs (7.7±1.4) L/min; 1 h: (5.3±0.7) L/min vs (7.4±1.5) L/min; 6 h: (4.6±0.6) L/min vs (6.8±1.4) L/min; 12 h: (5.1±0.9) L/min vs (7.6±1.6) L

  2. Right atrial tamponade complicating cardiac operation: clinical, hemodynamic, and scintigraphic correlates

    Energy Technology Data Exchange (ETDEWEB)

    Bateman, T.; Gray, R.; Chaux, A.; Lee, M.; De Robertis, M.; Berman, D.; Matloff, J.

    1982-09-01

    Persistent bleeding into the pericardial space in the early hours after cardiac operation not uncommonly results in cardiac tamponade. Single chamber tamponade also might be expected, since in this setting the pericardium frequently contains firm blood clots localized to the area of active bleeding. However, this complication has received very little attention in the surgical literature. We are therefore providing documentation that isolated right atrial tamponade can occur as a complication of cardiac operation and that there exists a potential for misdiagnosis and hence incorrect treatment of this condition. Right atrial tamponade may be recognized by a combination of low cardiac output, low blood pressure, prominent neck veins, right atrial pressure in excess of pulmonary capillary wedge pressure and right ventricular end-diastolic pressure, and a poor response to plasma volume expansion. Findings on chest roentgenogram and gated wall motion scintigraphy may be highly suggestive. This review should serve to increase awareness of this complication and to provide some helpful diagnostic clues.

  3. Right atrial tamponade complicating cardiac operation: clinical, hemodynamic, and scintigraphic correlates

    International Nuclear Information System (INIS)

    Persistent bleeding into the pericardial space in the early hours after cardiac operation not uncommonly results in cardiac tamponade. Single chamber tamponade also might be expected, since in this setting the pericardium frequently contains firm blood clots localized to the area of active bleeding. However, this complication has received very little attention in the surgical literature. We are therefore providing documentation that isolated right atrial tamponade can occur as a complication of cardiac operation and that there exists a potential for misdiagnosis and hence incorrect treatment of this condition. Right atrial tamponade may be recognized by a combination of low cardiac output, low blood pressure, prominent neck veins, right atrial pressure in excess of pulmonary capillary wedge pressure and right ventricular end-diastolic pressure, and a poor response to plasma volume expansion. Findings on chest roentgenogram and gated wall motion scintigraphy may be highly suggestive. This review should serve to increase awareness of this complication and to provide some helpful diagnostic clues

  4. Consenso brasileiro de monitorização e suporte hemodinâmico - parte III: métodos alternativos de monitorização do débito cardíaco e da volemia Brazilian consensus of monitoring and hemodynamic support - part III: alternative methods for cardiac output monitoring and volemia estimation

    Directory of Open Access Journals (Sweden)

    Guilherme Schettino

    2006-03-01

    Full Text Available JUSTIFICATIVA E OBJETIVOS: A interpretação do débito cardíaco e da pré-carga como números absolutos não traz grandes informações sobre a hemodinâmica do paciente crítico. Em contrapartida, a monitorização da resposta do débito cardíaco à expansão volêmica ou suporte inotrópico é uma ferramenta muito útil na unidade de terapia intensiva, quando o paciente apresenta algum sinal de má perfusão tecidual. Apesar do CAP ser considerado como " padrão-ouro" na avaliação destes parâmetros, foram desenvolvidas tecnologias alternativas bastante confiáveis para a sua monitorização. MÉTODO: O processo de desenvolvimento de recomendações utilizou o método Delphi modificado para criar e quantificar o consenso entre os participantes. A AMIB determinou um coordenador para o consenso, o qual escolheu seis especialistas para comporem o comitê consultivo. Outros 18 peritos de diferentes regiões do país foram selecionados para completar o painel de 25 especialistas, médicos e enfermeiros. Um levantamento bibliográfico na MEDLINE de artigos na língua inglesa foi realizado no período de 1966 a 2004. RESULTADOS: Foram apresentadas recomendações referentes à análise da variação da pressão arterial durante ventilação mecânica, débito cardíaco contínuo por contorno de pulso arterial, débito cardíaco por diluição do lítio, Doppler transesofágico, bioimpedância transtorácica, ecocardiografia e reinalação parcial de gás carbônico. CONCLUSÕES: As novas e menos invasivas técnicas para medida do débito cardíaco, pré-carga e fluidoresponsividade apresentam adequada precisão e podem ser uma alternativa ao uso do CAP em pacientes graves.BACKGROUND AND OBJECTIVES: Cardiac output and preload as absolute data do not offer helpful information about the hemodynamic of critically ill patients. However, monitoring the response of these variables to volume challenge or inotropic drugs is a very useful tool in the

  5. Impact of increasing levels of advanced iterative reconstruction on image quality in low-dose cardiac CT angiography

    Energy Technology Data Exchange (ETDEWEB)

    Kroepil, P.; Antoch, G. [Duesseldorf Univ. (Germany). Dept. of Diagnostic and Interventional Radiology; Bigdeli, A.H.; Cohnen, M. [Staedtische Kliniken Neuss Lukaskrankenhaus GmbH, Neuss (Germany). Inst. of Clinical Radiology; Nagel, H.D. [Dr. HD Nagel, Buchholz (Germany). Science and Technology for Radiology

    2014-06-15

    Purpose: To investigate the effects of an advanced iterative reconstruction (IR) technique on subjective and objective image quality (IQ) in low-dose cardiac CT angiography (CCTA). Materials and Methods: 30 datasets of prospectively triggered 'step-and-shoot' CCTA scans acquired on a 256-slice CT scanner with optimized exposure settings were processed on a prototype IR system using filtered back-projection (FBP) and 4 levels of advanced IR (iDose4, Philips) providing incremental rates of IR (level 2, 4, 6, 7). In addition, the effects of different reconstruction kernels (semi-smooth [CB], standard with edge-enhancement [XCB]) and a 'multi-resolution' feature [MR] to preserve the noise power spectrum were evaluated resulting in a total of n = 480 image sets. Contrast-to-noise ratios (CNR) were computed from regions of interest at 9 coronary locations. The subjective IQ was rated on a 4-point-scale with 'classic' image appearance and noise-related artifacts as main criteria. Results: At an effective dose of 1.7 ± 0.7 mSv, the CNR significantly improved with every increasing level of IR (range: 14.2-27.8; p < 0.001) with the best objective IQ at the highest level of IR (level 7). The subjective IQ, however, was rated best at the medium level of IR (level 4) with minimal artifacts and a more 'classic' image appearance when compared to higher IR levels. The XCB kernel provided better subjective ratings than CB (p < 0.05) and the MR feature further increased the IQ at a high level of IR. Conclusion: The objective IQ of low-dose CCTA progressively improves with an increasing level of IR. The best subjective IQ, however, is reached at medium levels of IR combined with an edge-enhancing kernel allowing for preservation of a 'classic' image appearance suggesting application in the clinical routine. (orig.)

  6. Efficacy of chronic statin therapy on major cardiac events after coronary artery bypass grafting: low-dose versus high-dose

    Directory of Open Access Journals (Sweden)

    Ayşegül Kunt

    2015-08-01

    Full Text Available Aim To investigate whether chronic statin treatment after coronary artery bypass grafting (CABG protects patients from major cardiac events and provides percutaneous coronary intervention (PCI free survival. Methods A total of 232 patients with previous CABG and chronic statin therapy were selected retrospectively and were divided into two groups according to a dosage of atorvastatin per day, e. g., 20 mg or 40 mg. Groups were compared for the major cardiac events and freedom from PCI by Kaplan Meier analysis as the primary end point. Patency of grafts including left internal thoracic artery (LITA and saphenous vein (SVG and progression of non-grafted native vessel disease were also evaluated as secondary end points. Results Cardiac mortality, periprocedural myocardial infarction (MI, target vessel revascularization and percutaneous coronary intervention free survival were as follows: 2.9% versus 2.1% (p=1.000; 16.1% versus 21.1% (p=0.331; 56.93% versus 52.63% (p>0.005; 58.4% versus 63.2% (log-rank test; p= 0.347 in atorvastatin 20 mg and atorvastatin 40 mg groups, respectively. However, these results were not statistically significant between two groups (p>0.005. Patency of openness of grafts including LITA and SVG and progression of non-grafted native vessel disease were similar between groups (p=0.112, p=0.779, p=0.379 and p=0.663, respectively. Conclusion Low-dose long-term statin treatment had similar outcomes on major cardiac events and identical rate of freedom from percutaneous coronary intervention after coronary artery bypass grafting compared with high-dose long-term statin treatment. It is better to start from low dose statin treatment after surgical interventions.

  7. Feasibility of epicardial adipose tissue quantification in non-ECG-gated low-radiation-dose CT: comparison with prospectively ECG-gated cardiac CT

    International Nuclear Information System (INIS)

    Background: Epicardial adipose tissue (EAT) is an important indicator of cardiovascular risk. This parameter is generally assessed on ECG-gated computed tomography (CT) images. Purpose: To evaluate feasibility and reliability of EAT quantification on non-gated thoracic low-radiation-dose CT examinations with respect to prospectively ECG-gated cardiac CT acquisition. Material and Methods: Sixty consecutive asymptomatic smokers (47 men; mean age 64 ± 9.8 years) underwent low-dose CT of the chest and prospectively ECG-gated cardiac CT acquisitions (64-slice dual-source CT). The two examinations were reconstructed with the same range, field of view, slice thickness, and convolution algorithm. Two independent observers blindly quantified EAT volume using commercially available software. Data were compared with paired sample Student t-test, concordance correlation coefficients (CCC), and Bland-Altman plots. Results: No statistically significant difference was observed for EAT volume quantification with low-dose-CT (141.7 ± 58.3 mL) with respect to ECG-gated CT (142.7 ± 57.9 mL). Estimation of CCC showed almost perfect concordance between the two techniques for EAT-volume assessment (CCC, 0.99; mean difference, 0.98 ± 5.1 mL). Inter-observer agreement for EAT volume estimation was CCC: 0.96 for low-dose-CT examinations and 0.95 for ECG-gated CT. Conclusion: Non-gated low-dose CT allows quantifying EAT with almost the same concordance and reliability as using dedicated prospectively ECG-gated cardiac CT acquisition protocols

  8. Feasibility of epicardial adipose tissue quantification in non-ECG-gated low-radiation-dose CT: comparison with prospectively ECG-gated cardiac CT

    Energy Technology Data Exchange (ETDEWEB)

    Simon-Yarza, Isabel; Viteri-Ramirez, Guillermo; Saiz-Mendiguren, Ramon; Slon-Roblero, Pedro J.; Paramo, Maria [Dept. of Radiology, Clinica Univ. de Navarra, Pamplona (Spain); Bastarrika, Gorka [Dept. of Radiology, Clinica Univ. de Navarra, Pamplona (Spain); Cardiac Imaging Unit, Clinica Univ. de Navarra, Pamplona (Spain)], e-mail: bastarrika@unav.es

    2012-06-15

    Background: Epicardial adipose tissue (EAT) is an important indicator of cardiovascular risk. This parameter is generally assessed on ECG-gated computed tomography (CT) images. Purpose: To evaluate feasibility and reliability of EAT quantification on non-gated thoracic low-radiation-dose CT examinations with respect to prospectively ECG-gated cardiac CT acquisition. Material and Methods: Sixty consecutive asymptomatic smokers (47 men; mean age 64 {+-} 9.8 years) underwent low-dose CT of the chest and prospectively ECG-gated cardiac CT acquisitions (64-slice dual-source CT). The two examinations were reconstructed with the same range, field of view, slice thickness, and convolution algorithm. Two independent observers blindly quantified EAT volume using commercially available software. Data were compared with paired sample Student t-test, concordance correlation coefficients (CCC), and Bland-Altman plots. Results: No statistically significant difference was observed for EAT volume quantification with low-dose-CT (141.7 {+-} 58.3 mL) with respect to ECG-gated CT (142.7 {+-} 57.9 mL). Estimation of CCC showed almost perfect concordance between the two techniques for EAT-volume assessment (CCC, 0.99; mean difference, 0.98 {+-} 5.1 mL). Inter-observer agreement for EAT volume estimation was CCC: 0.96 for low-dose-CT examinations and 0.95 for ECG-gated CT. Conclusion: Non-gated low-dose CT allows quantifying EAT with almost the same concordance and reliability as using dedicated prospectively ECG-gated cardiac CT acquisition protocols.

  9. Low-dose vasopressin infusion results in increased mortality and cardiac dysfunction following ischemia-reperfusion injury in mice

    OpenAIRE

    Indrambarya, Toonchai; Boyd, John H; Wang, Yingjin; McConechy, Melissa; Keith R Walley

    2009-01-01

    Introduction Arginine vasopressin is a vasoactive drug commonly used in distributive shock states including mixed shock with a cardiac component. However, the direct effect of arginine vasopressin on the function of the ischemia/reperfusion injured heart has not been clearly elucidated. Methods We measured left ventricular ejection fraction using trans-thoracic echocardiography in C57B6 mice, both in normal controls and following ischemia/reperfusion injury induced by a one hour ligation of t...

  10. Usefulness of High-Sensitivity Cardiac Troponin T for the Identification of Outlier Patients With Diffuse Coronary Atherosclerosis and Low-Risk Factors.

    Science.gov (United States)

    Magnoni, Marco; Masson, Serge; Andreini, Daniele; Moccetti, Tiziano; Modena, Maria Grazia; Canestrari, Mauro; Berti, Sergio; Casolo, Giancarlo; Gabrielli, Domenico; Marraccini, Paolo; Pontone, Gianluca; Latini, Roberto; Maggioni, Aldo Pietro; Maseri, Attilio

    2016-05-01

    Novel high-sensitivity assay can detect very low levels of circulating cardiac troponin (hs-cTnT) in apparently healthy subjects. Within normal range, higher levels are associated with coronary artery disease (CAD) and cardiac abnormalities commonly associated to traditional risk factors (RFs) for CAD. Therefore, we investigated the relation between circulating hs-cTnT and CAD in patients with a spectrum of RF burden aiming to assess the added value of hs-cTnT to identify "outlier" patients with CAD despite a low RF burden. Hs-cTnT was measured in 525 stable patients without previous diagnosis of ischemic heart disease with 0 to 1 RF, excluded diabetes, (low-RF group, n = 263) or ≥2 RFs (multiple-RF group, n = 262) and without CAD (segment involvement score = 0) or diffuse CAD (segment involvement score >5) at coronary computed tomography angiography. Outlier patients with diffuse CAD despite low-RF burden had similar extent, severity, and plaque composition than patients with multiple RFs. Overall, hs-cTnT was measurable in 81% of patients with median value of 6.0 ng/L. In both groups, hs-cTnT concentration was higher in patients with CAD than in patients with normal coronary arteries (p 6 ng/L) was independently associated with CAD in low-RF group only. Despite very low circulating concentrations, hs-cTnT may identify with a good accuracy the outlier patients with diffuse CAD despite low-RF burden. PMID:26976791

  11. Cardiac rehabilitation

    Science.gov (United States)

    ... attack or other heart problem. You might consider cardiac rehab if you have had: Heart attack Coronary heart disease (CHD) Heart failure Angina (chest pain) Heart or heart valve surgery Heart transplant Procedures such as angioplasty and stenting In some ...

  12. Cardiac Rehabilitation

    Science.gov (United States)

    Cardiac rehabilitation (rehab) is a medically supervised program to help people who have A heart attack Angioplasty or coronary artery bypass grafting for coronary heart disease A heart valve repair or replacement A ...

  13. Impaired progenitor cell function in HIV-negative infants of HIV-positive mothers results in decreased thymic output and low CD4 counts

    DEFF Research Database (Denmark)

    Nielsen, S D; Jeppesen, D L; Kolte, L;

    2001-01-01

    and fetal thymic organ cultures (FTOCs). Lower naive CD4 counts (459.3 +/- 68.9 vs 1128.9 +/- 146.8 cells/microL, P <.001) and reduced thymic output in infants of HIV-positive mothers were found (frequency of CD4(+) cells with TRECs was 3.6% +/- 0.7% compared with 14.3% +/- 2.2% in controls, P <.001......). In combination with lower red blood cell counts in infants of HIV-positive mothers, this finding suggested impairment of progenitor cell function. Indeed, progenitors from infants of HIV-positive mothers had decreased cloning efficiency (15.7% +/- 2.6% vs 55.8% +/- 15.9%, P =.009) and seemed to...... generate fewer T cells in FTOCs. In conclusion, lower numbers of naive CD4(+) cells and reduced thymic output in HIV-negative infants of HIV-positive mothers may be due to impaired progenitor cell function....

  14. Cardiac factors in orthostatic hypotension

    Science.gov (United States)

    Löllgen, 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.

  15. Cardiac failure due to arteriovenous fistula with brachiocephalic stenosis: a gated heart case study

    International Nuclear Information System (INIS)

    Full text: There are numerous causes of cardiac failure of which the commonest in our community include ischaemic cardiomyopathy, post-viral cardiomyopathy, alcohol-induced cardiomyopathy and drug-induced cardiomyopathy. All these entities cause low output cardiac failure however high output cardiac failure is also well recognised. This includes heart failure related to such conditions as hyperthyroidism, anaemia, pregnancy, beri-beri, and Paget's disease. A rare cause of high output cardiac failure is an arteriovenous fistula. We present an unusual case of a patient with end-stage renal failure on haemodialysis who developed extensive dilatation of their left arm arteriovenous fistula secondary to bachiocephalic vein stenosis. The labelled red blood cell gated heart blood pool study demonstrated decreased left ventricular function and extensive pooling of blood within the tortuous dilated left arm vessels. A follow-up study post-ligation of the arteriovenous fistula showed improvement of the left ventricular ejection fraction. The associated contrast venography findings are also demonstrated. Copyright (2003) The Australian and New Zealand Society of Nuclear Medicine Inc

  16. Relationship between cardiac function and resting cerebral blood flow

    DEFF Research Database (Denmark)

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

    2014-01-01

    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......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...... 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...

  17. Low nourishment of B-vitamins is associated with hyperhomocysteinemia and oxidative stress in newly diagnosed cardiac patients.

    Science.gov (United States)

    Waly, Mostafa I; Ali, Amanat; Al-Nassri, Amira; Al-Mukhaini, Mohamed; Valliatte, John; Al-Farsi, Yahya

    2016-01-01

    We are currently witnessing a dramatic change in lifestyle and food choices that is accompanied with an increase in the rate of morbidity and mortality from cardiovascular diseases (CVD). Although studies have reported an association of CVD with hyperhomocysteinemia-mediated oxidative stress, the biochemical basis is not known. This case-control study was aimed to evaluate the nutritional and biochemical status of B-vitamins in relation to hyperhomocysteinemia and oxidative stress in newly diagnosed cardiac patients. The retrospective dietary intake of the study subjects (cases and controls) was estimated using a semi-quantitative food frequency questionnaire, and fasting blood samples were drawn to assess their serum levels of B-vitamins (folate, vitamins B6 and B12), homocysteine (HCY), and oxidative stress indices such as glutathione (GSH), total antioxidant capacity (TAC), malondialdehyde (MDA), and nitrites and nitrates (NN). It was observed that the cases had a lower dietary intake of B-vitamins as compared to their matched control subjects as well as to the corresponding recommended dietary allowances. Biochemical analysis of cases, as compared to controls, indicated depletion of GSH, impairment of TAC, and an elevation in the serum levels of HCY, MDA, and NN. These results suggest that lower status (dietary intake and serum levels) of B-vitamins is involved in the etiology of hyperhomocysteinemia and oxidative stress, the typical risk factors for CVD. PMID:26246496

  18. Input-output supervisor

    International Nuclear Information System (INIS)

    The input-output supervisor is the program which monitors the flow of informations between core storage and peripheral equipments of a computer. This work is composed of three parts: 1 - Study of a generalized input-output supervisor. With sample modifications it looks like most of input-output supervisors which are running now on computers. 2 - Application of this theory on a magnetic drum. 3 - Hardware requirement for time-sharing. (author)

  19. Cardiac CT

    Energy Technology Data Exchange (ETDEWEB)

    Dewey, Marc [Charite - Universitaetsmedizin Berlin (Germany). Inst. fuer Radiologie

    2011-07-01

    Computed tomography of the heart has become a highly accurate diagnostic modality that is attracting increasing attention. This extensively illustrated book aims to assist the reader in integrating cardiac CT into daily clinical practice, while also reviewing its current technical status and applications. Clear guidance is provided on the performance and interpretation of imaging using the latest technology, which offers greater coverage, better spatial resolution, and faster imaging. The specific features of scanners from all four main vendors, including those that have only recently become available, are presented. Among the wide range of applications and issues to be discussed are coronary artery bypass grafts, stents, plaques, and anomalies, cardiac valves, congenital and acquired heart disease, and radiation exposure. Upcoming clinical uses of cardiac CT, such as plaque imaging and functional assessment, are also explored. (orig.)

  20. Cardiac echinococcosis

    Directory of Open Access Journals (Sweden)

    Ivanović-Krstić Branislava A.

    2002-01-01

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

  1. Cardiac sarcoidosis

    Science.gov (United States)

    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

  2. Low dose prospective ECG-gated delayed enhanced dual-source computed tomography in reperfused acute myocardial infarction comparison with cardiac magnetic resonance

    International Nuclear Information System (INIS)

    Purpose: To determine whether prospective electrocardiogram (ECG)-gated delayed contrast-enhanced dual-source computed tomography (DCE-DSCT) can accurately delineate the extension of myocardial infarction (MI) compared with delayed enhanced cardiac MR (DE-MR). Material and methods: Eleven patients were examined using dual-source CT and cardiac MR in 2 weeks after a first reperfused MI. DCE-DSCT scan protocol was performed with prospective ECG-gating sequential scan model 7 min after contrast administration. In a 17-model, infarcted myocardium detected by DE-MR was categorized as transmural and subendocardial extension. Segment of infarcted location and graded transmurality were compared between DCE-MDCT and DE-MR. Results: In all eleven patients, diagnostic quality was obtained for depicting delayed enhanced myocardium. Agreement between DCE-DSCT and MR was good on myocardial segment based comparison (kappa = 0.85, p < 0.001), and on transmural and subendocardial infarction type comparison (kappa = 0.82, p < 0.001, kappa = 0.52, p < 0.001, respectively). CT value was higher on infarcted region than that of normal region (100.02 ± 9.57 HU vs. 72.63 ± 7.32 HU, p < 0.001). Radiation dose of prospectively ECG-gating protocol were 0.99 ± 0.08 mSv (0.82-1.19 mSv). Conclusions: Prospective ECG-gated DCE-DSCT can accurately assess the extension and the patterns of myocardial infarction with low radiation dose.

  3. Low dose prospective ECG-gated delayed enhanced dual-source computed tomography in reperfused acute myocardial infarction comparison with cardiac magnetic resonance

    Energy Technology Data Exchange (ETDEWEB)

    Wang Rui, E-mail: rui_wang1979@yahoo.cn [Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, 100029 Beijing (China); Zhang Zhaoqi, E-mail: zhaoqi5000@vip.sohu.com [Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, 100029 Beijing (China); Xu Lei, E-mail: leixu2001@hotmail.com [Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, 100029 Beijing (China); Ma Qin, E-mail: tel1367@gmail.com [Department of Emergency, Beijing Anzhen Hospital, Capital Medical University, 100029 Beijing (China); He Yi, E-mail: heyi139@sina.com [Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, 100029 Beijing (China); Lu Dongxu, E-mail: larry.hi@163.com [Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, 100029 Beijing (China); Yu Wei, E-mail: yuwei02@gmail.com [Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, 100029 Beijing (China); Fan Zhanming, E-mail: fanzm120@tom.com [Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, 100029 Beijing (China)

    2011-11-15

    Purpose: To determine whether prospective electrocardiogram (ECG)-gated delayed contrast-enhanced dual-source computed tomography (DCE-DSCT) can accurately delineate the extension of myocardial infarction (MI) compared with delayed enhanced cardiac MR (DE-MR). Material and methods: Eleven patients were examined using dual-source CT and cardiac MR in 2 weeks after a first reperfused MI. DCE-DSCT scan protocol was performed with prospective ECG-gating sequential scan model 7 min after contrast administration. In a 17-model, infarcted myocardium detected by DE-MR was categorized as transmural and subendocardial extension. Segment of infarcted location and graded transmurality were compared between DCE-MDCT and DE-MR. Results: In all eleven patients, diagnostic quality was obtained for depicting delayed enhanced myocardium. Agreement between DCE-DSCT and MR was good on myocardial segment based comparison (kappa = 0.85, p < 0.001), and on transmural and subendocardial infarction type comparison (kappa = 0.82, p < 0.001, kappa = 0.52, p < 0.001, respectively). CT value was higher on infarcted region than that of normal region (100.02 {+-} 9.57 HU vs. 72.63 {+-} 7.32 HU, p < 0.001). Radiation dose of prospectively ECG-gating protocol were 0.99 {+-} 0.08 mSv (0.82-1.19 mSv). Conclusions: Prospective ECG-gated DCE-DSCT can accurately assess the extension and the patterns of myocardial infarction with low radiation dose.

  4. Low-Loss Coupling of Quantum Cascade Lasers into Hollow-Core Waveguides with Single-Mode Output in the 3.7–7.6 μm Spectral Range

    Directory of Open Access Journals (Sweden)

    Pietro Patimisco

    2016-04-01

    Full Text Available We demonstrated low-loss and single-mode laser beam delivery through hollow-core waveguides (HCWs operating in the 3.7–7.6 μm spectral range. The employed HCWs have a circular cross section with a bore diameter of 200 μm and metallic/dielectric internal coatings deposited inside a glass capillary tube. The internal coatings have been produced to enhance the spectral response of the HCWs in the range 3.5–12 µm. We demonstrated Gaussian-like outputs throughout the 4.5–7.6 µm spectral range. A quasi single-mode output beam with only small beam distortions was achieved when the wavelength was reduced to 3.7 μm. With a 15-cm-long HCW and optimized coupling conditions, we measured coupling efficiencies of >88% and transmission losses of <1 dB in the investigated infrared spectral range.

  5. Low-Loss Coupling of Quantum Cascade Lasers into Hollow-Core Waveguides with Single-Mode Output in the 3.7-7.6 μm Spectral Range.

    Science.gov (United States)

    Patimisco, Pietro; Sampaolo, Angelo; Mihai, Laura; Giglio, Marilena; Kriesel, Jason; Sporea, Dan; Scamarcio, Gaetano; Tittel, Frank K; Spagnolo, Vincenzo

    2016-01-01

    We demonstrated low-loss and single-mode laser beam delivery through hollow-core waveguides (HCWs) operating in the 3.7-7.6 μm spectral range. The employed HCWs have a circular cross section with a bore diameter of 200 μm and metallic/dielectric internal coatings deposited inside a glass capillary tube. The internal coatings have been produced to enhance the spectral response of the HCWs in the range 3.5-12 µm. We demonstrated Gaussian-like outputs throughout the 4.5-7.6 µm spectral range. A quasi single-mode output beam with only small beam distortions was achieved when the wavelength was reduced to 3.7 μm. With a 15-cm-long HCW and optimized coupling conditions, we measured coupling efficiencies of >88% and transmission losses of <1 dB in the investigated infrared spectral range. PMID:27089343

  6. Low-Loss Coupling of Quantum Cascade Lasers into Hollow-Core Waveguides with Single-Mode Output in the 3.7–7.6 μm Spectral Range

    Science.gov (United States)

    Patimisco, Pietro; Sampaolo, Angelo; Mihai, Laura; Giglio, Marilena; Kriesel, Jason; Sporea, Dan; Scamarcio, Gaetano; Tittel, Frank K.; Spagnolo, Vincenzo

    2016-01-01

    We demonstrated low-loss and single-mode laser beam delivery through hollow-core waveguides (HCWs) operating in the 3.7–7.6 μm spectral range. The employed HCWs have a circular cross section with a bore diameter of 200 μm and metallic/dielectric internal coatings deposited inside a glass capillary tube. The internal coatings have been produced to enhance the spectral response of the HCWs in the range 3.5–12 µm. We demonstrated Gaussian-like outputs throughout the 4.5–7.6 µm spectral range. A quasi single-mode output beam with only small beam distortions was achieved when the wavelength was reduced to 3.7 μm. With a 15-cm-long HCW and optimized coupling conditions, we measured coupling efficiencies of >88% and transmission losses of <1 dB in the investigated infrared spectral range. PMID:27089343

  7. Cardiac Pacemakers

    International Nuclear Information System (INIS)

    A complete survey of physiological biophysical,clinical and engineering aspects of cardiac facing,including the history and an assessment of possible future developments.Among the topics studied are: pacemakers, energy search, heart stimulating with pacemakers ,mathematical aspects of the electric cardio stimulation chronic, pacemaker implants,proceeding,treatment and control

  8. Effect of low-output He-Ne laser rays on the colony-forming ability of the cells of mice lymphoma

    International Nuclear Information System (INIS)

    The effect of low energy He-Ne laser radiation on the survival of mouse lymphoma P388 cell cultures was studied on the basis of the colony forming ability. Irradiation with 1.3 and 9 joule of 5 and 10 mW He-Ne lasers, resp., seemed to cause a relatively low cell necrosis. The survival curve did not show the shape characteristic of ionizing radiation. (author)

  9. Output hardcopy devices

    CERN Document Server

    Durbeck, Robert

    1988-01-01

    Output Hardcopy Devices provides a technical summary of computer output hardcopy devices such as plotters, computer output printers, and CRT generated hardcopy. Important related technical areas such as papers, ribbons and inks, color techniques, controllers, and character fonts are also covered. Emphasis is on techniques primarily associated with printing, as well as the plotting capabilities of printing devices that can be effectively used for computer graphics in addition to their various printing functions. Comprised of 19 chapters, this volume begins with an introduction to vector and ras

  10. Prognostic factors affecting the all-cause death and sudden cardiac death rates of post myocardial infarction patients with low left ventricular ejection fraction

    Institute of Scientific and Technical Information of China (English)

    DAI Shi-mo; ZHANG Shu; CHEN Ke-ping; HUA Wei; WANG Fang-zheng; CHEN Xin

    2009-01-01

    Background Post myocardial infarction (post-MI) patients with low left ventricular ejection fraction (LVEF) have been candidates for an implantable cardioverter-deflbrillator (ICD) since the Multicenter Automatic Defibrillator Implantation Trail II (MADIT II).However,due to the high costs of ICDs,widespread usage has not been accepted.Therefore,further risk stratification for post-MI patients with low LVEF may aid in the selection of patients that will benefit most from ICD treatment.Methods Four hundred and seventeen post-MI patients with low LVEF (≤35%) were enrolled in the study.All the patients received standard examination and proper treatment and were followed up to observe the all-cause death rate and sudden cardiac death (SCD) rate.Then COX proportional-hazards regression model was used to investigate the clinical factors which affect the all-cause death rate and SCD rate.Results Of 55 patients who died during (32±24) months of follow-up,37 (67%) died suddenly.After adjusting for baseline clinical characteristics,multivariate COX proportional-hazards regression model identified the following variables associated with death from all causes:New York Heart Association (NYHA) heart failure class ≥111 (Hazard ratio:2.361),LVEF ≤20% (Hazard ratio:2.514),sustained ventricular tachycardia (Hazard ratio:6.453),and age ≥70 years (Hazard ratio:3.116).The presence of sustained ventricular tachycardia (Hazard ratio:6.491) and age ≥70 years (Hazard ratio:2.694) were specifically associated with SCD.Conclusions In the post-MI patients with low LVEF,factors as LVEF ≤20%,age ≥70 years,presence of ventricular tachycardia,and NYHA heart failure class≥111 predict an adverse outcome.The presence of sustained ventricular tachycardia and age ≥70 years was associated with occurrence of SCD in these patients.

  11. Living high training low induces physiological cardiac hypertrophy accompanied by down-regulation and redistribution of the renin-angiotensin system

    Institute of Scientific and Technical Information of China (English)

    Wei SHI; J Gary MESZAROS; Shao-ju ZENG; Ying-yu SUN; Ming-xue ZUO

    2013-01-01

    Aim:Living high training low" (LHTL) is an exercise-training protocol that refers living in hypoxia stress and training at normal level of O2.In this study,we investigated whether LHTL caused physiological heart hypertrophy accompanied by changes of biomarkers in reninangiotensin system in rats.Methods:Adult male SD rats were randomly assigned into 4 groups,and trained on living low-sedentary (LLS,control),living lowtraining low (LLTL),living high-sedentary (LHS) and living high-training low (LHTL) protocols,respectively,for 4 weeks.Hematological parameters,hemodynamic measurement,heart hypertrophy and plasma angiotensin Ⅱ (Ang Ⅱ) level of the rats were measured.The gene and protein expression of angiotensin-converting enzyme (ACE),angiotensinogen (AGT) and angiotensin Ⅱ receptor Ⅰ (AT1) in heart tissue was assessed using RT-PCR and immunohistochemistry,respectively.Results:LLTL,LHS and LHTL significantly improved cardiac function,increased hemoglobin concentration and RBC.At the molecular level,LLTL,LHS and LHTL significantly decreased the expression of ACE,AGT and AT1 genes,but increased the expression of ACE and AT1 proteins in heart tissue.Moreover,ACE and AT1 protein expression was significantly increased in the endocardium,but unchanged in the epicardium.Conclusion:LHTL training protocol suppresses ACE,AGT and AT1 gene expression in heart tissue,but increases ACE and AT1 protein expression specifically in the endocardium,suggesting that the physiological heart hypertrophy induced by LHTL is regulated by regionspecific expression of renin-angiotensin system components.

  12. VMS forms Output Tables

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These output tables contain parsed and format validated data from the various VMS forms that are sent from any given vessel, while at sea, from the VMS devices on...

  13. Output stages inside a negative feedback loop: application to a low-voltage three-phase DC-AC converter for educational purposes

    CERN Document Server

    Llopis, Francisco

    2013-01-01

    The circuit presented in this paper aims at providing three 40 Vpp 50Hz AC voltages sources with 120-degree phase separation between them. This is a fully analogue circuit that uses standard, low-cost electronic components without resorting to a microcontroller as previously proposed by Shirvasar et al [1]. This circuit may serve as a basis for a low-voltage 3P-AC power supply that students may safely use to realize experiments, i.e. about the principles and applications of three-phase AC power lines, without the risk of electric shocks.

  14. Cardiac responses to hypoxia and reoxygenation in Drosophila.

    Science.gov (United States)

    Zarndt, Rachel; Piloto, Sarah; Powell, Frank L; Haddad, Gabriel G; Bodmer, Rolf; Ocorr, Karen

    2015-12-01

    An adequate supply of oxygen is important for the survival of all tissues, but it is especially critical for tissues with high-energy demands, such as the heart. Insufficient tissue oxygenation occurs under a variety of conditions, including high altitude, embryonic and fetal development, inflammation, and thrombotic diseases, often affecting multiple organ systems. Responses and adaptations of the heart to hypoxia are of particular relevance in human cardiovascular and pulmonary diseases, in which the effects of hypoxic exposure can range in severity from transient to long-lasting. This study uses the genetic model system Drosophila to investigate cardiac responses to acute (30 min), sustained (18 h), and chronic (3 wk) hypoxia with reoxygenation. Whereas hearts from wild-type flies recovered quickly after acute hypoxia, exposure to sustained or chronic hypoxia significantly compromised heart function upon reoxygenation. Hearts from flies with mutations in sima, the Drosophila homolog of the hypoxia-inducible factor alpha subunit (HIF-α), exhibited exaggerated reductions in cardiac output in response to hypoxia. Heart function in hypoxia-selected flies, selected over many generations for survival in a low-oxygen environment, revealed reduced cardiac output in terms of decreased heart rate and fractional shortening compared with their normoxia controls. Hypoxia-selected flies also had smaller hearts, myofibrillar disorganization, and increased extracellular collagen deposition, consistent with the observed reductions in contractility. This study indicates that longer-duration hypoxic insults exert deleterious effects on heart function that are mediated, in part, by sima and advances Drosophila models for the genetic analysis of cardiac-specific responses to hypoxia and reoxygenation. PMID:26377557

  15. Cardiac rhabdomyosarcoma

    OpenAIRE

    Chlumský, Jaromír; Holá, Dana; Hlaváček, Karel; Michal, Michal; Švec, Alexander; Špatenka, Jaroslav; Dušek, Jan

    2001-01-01

    Cardiac sarcoma is a very rare neoplasm and is difficult to diagnose. The case of a 51-year-old man with a left atrial tumour, locally recurrent three months after its surgical removal, is presented. Computed tomography showed metastatic spread to the lung parenchyma. On revised histology, the mass extirpated was a sarcoma. Because of the metastatic spread, further therapy was symptomatic only; the patient died 15 months after the first manifestation of his problems. Immunohistochemical stain...

  16. Cardiac Calcification

    Directory of Open Access Journals (Sweden)

    Morteza Joorabian

    2011-05-01

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

  17. Effects of Exercise Training on Haematology and Maximal Cardiac Output

    DEFF Research Database (Denmark)

    Bonne, Thomas Christian

    the heart ultra structure possibly also play a role for improving Qmax. Other mechanisms that can improve exercise capacity include hypoxia. It is universally accepted that hypoxia is a main stimulant of erythropoiesis and altitude training is considered a possibility to increase red blood cell volume...... of the exercise induced increase in Qmax whereas structural changes to the heart may require years of training to exert an effect. Classical altitude training has the potential to further increase Hbmass and BV through an elevation in RCV and a strong tendency towards improvements in performance was......Qmax may increase within a few weeks of exercise and the underlying mechanisms leading to this are likely to be multi-factorial. Plasma volume is generally thought to rapidly increase in response to exercise training driving an increase in Qmax and hence VO2max. Structural and functional changes to...

  18. Normal value of functional parameters in gated myocardial perfusion SPECT in patients with low risk of coronary artery disease: emory cardiac tool box program

    Energy Technology Data Exchange (ETDEWEB)

    Kang, D. Y.; Kim, M. H.; Kim, Y. D.; Kim, D. K. [Donga University College of Medicine, Busan (Korea, Republic of)

    2002-07-01

    Absolute value of the functional data of gated myocardial perfusion SPECT is necessary to determine that individual patient is normal or not. Tc-99m MIBI gated myocardial perfusion SPECT was performed using emory cardiac tool box program. All patients (M:F=15:36, age 64{+-}10 yrs) showed normal myocardial perfusion. The patients with following characteristics were excluded; previous angina or MI, ECG change with Q wave or ST-T change, diabetes mellitus, hypercholesterolemia, typical chest pain and hypertension. In all patients, myocardial mass is 117{+-}23 g in stress gated SPECT, 106{+-}22 g in stress ungated SPECT and 102{+-}21 g in rest ungated SPECT. EDV is 90{+-}28 ml, ESV 26{+-}20 ml, SV 66{+-}21 ml, EF 73{+-}10 % and TID 1.06{+-}0.14. Myocardial mass in rest ungated SPECT is significantly different between men and women (p=0.025). Myocardial mass is significantly different between stress gated SPECT and stress ungated SPECT (p=0.000), and between stress ungated SPECT and rest ungated SPECT (p=0.003). We provide normal value of functional parameters to determine the abnormality of individual patients in patients with low risk of coronary artery disease.

  19. Normal value of functional parameters in gated myocardial perfusion SPECT in patients with low risk of coronary artery disease: emory cardiac tool box program

    International Nuclear Information System (INIS)

    Absolute value of the functional data of gated myocardial perfusion SPECT is necessary to determine that individual patient is normal or not. Tc-99m MIBI gated myocardial perfusion SPECT was performed using emory cardiac tool box program. All patients (M:F=15:36, age 64±10 yrs) showed normal myocardial perfusion. The patients with following characteristics were excluded; previous angina or MI, ECG change with Q wave or ST-T change, diabetes mellitus, hypercholesterolemia, typical chest pain and hypertension. In all patients, myocardial mass is 117±23 g in stress gated SPECT, 106±22 g in stress ungated SPECT and 102±21 g in rest ungated SPECT. EDV is 90±28 ml, ESV 26±20 ml, SV 66±21 ml, EF 73±10 % and TID 1.06±0.14. Myocardial mass in rest ungated SPECT is significantly different between men and women (p=0.025). Myocardial mass is significantly different between stress gated SPECT and stress ungated SPECT (p=0.000), and between stress ungated SPECT and rest ungated SPECT (p=0.003). We provide normal value of functional parameters to determine the abnormality of individual patients in patients with low risk of coronary artery disease

  20. 脉搏指示连续心排血量监测技术在骨盆骨折合并失血性休克患者中的应用及护理%Nursing of pulse-indicated continuous cardiac output technique in pelvic fracture patients with hemorrhagic shock

    Institute of Scientific and Technical Information of China (English)

    赵文静; 程人佳; 张庆红; 赵文州

    2015-01-01

    Objective To investigate the clinical nursing methods of pulse-indicated con-tinuous cardiac output(PICCO)system in pelvic fracture patients with hemorrhagic shock.Methods The clinical data of 82 pelvic fracture patients with hemorrhagic shock treated in emergency inten-sive care unit (EICU)were retrospectively analyzed.Results In 82 patients,74 improved patients transferred to other departments or discharged and 8 patients died including 6 patients with acute re-nal failure.Conclusion Pelvic fracture patients with hemorrhagic shock using PICCO technology can accurately reflect the volume state.The PICCO management and PICCO safety is the key to en-sure successful treatment.%目的:探讨脉搏指示连续心排血量监测技术(PICCO)在骨盆骨折合并失血性休克患者中的应用及护理方法。方法对急诊重症监护室(EICU)收治的82例骨盆骨折合并失血性休克患者的临床及护理资料进行回顾性分析。结果82例患者中,病情好转转科或出院74例,死亡8例,其中并发急性肾衰竭6例。结论骨盆骨折合并失血性休克患者采用 PICCO技术能精准反映患者的容量状态,在 PICCO 的管理和观察中保证 PICCO 监测安全有效是救治成功的关键。

  1. [Cardiac amyloidosis. General review].

    Science.gov (United States)

    Laraki, R

    1994-04-01

    Cardiac amyloidosis, most often of AL type, is a non-exceptional disease as it represents 5 to 10% of non-ischemic cardiomyopathies. It realizes typically a restrictive cardiomyopathy. Nevertheless the wide diversity of possible presentation makes it a "big shammer" which must be evoked in front of every unexplained cardiopathy after the age of forty. If some associated manifestations can rapidly suggest the diagnosis, as a peripheric neuropathy especially a carpal tunnel syndrome or palpebral ecchymosis, cardiac involvement can also evolve in an apparently isolated way. The most suggestive paraclinic elements for the diagnosis are, in one hand, the increased myocardial echogenicity with a "granular sparkling" appearance seen throughout all walls of the left ventricle and, in the other hand, the association of a thickened left ventricle and a low voltage (electrocardiogram could also show pseudo-infarct Q waves). In front of such aspects, the proof of amyloidosis is brought by an extra-cardiac biopsy or by scintigraphy with labelled serum amyloid P component, so that the indications of endomyocardial biopsy are very limited today. The identification of the amyloid nature of a cardiopathy has an direct therapeutic implication: it contra-indicates the use of digitalis, calcium channel blockers and beta-blockers. The treatment of AL amyloidosis (chemotherapy with alkylant agents) remains very unsatisfactory especially in the cardiac involvement which is the most frequent cause of death (in AL amyloidosis). Last, cardiac amyloidosis is a bad indication for transplantation which results are burden by rapid progression of deposits especially in the gastro-intestinal tract and the nervous system. PMID:8059146

  2. Cardiac valve calcifications on low-dose unenhanced ungated chest computed tomography: inter-observer and inter-examination reliability, agreement and variability

    International Nuclear Information System (INIS)

    To determine inter-observer and inter-examination variability for aortic valve calcification (AVC) and mitral valve and annulus calcification (MC) in low-dose unenhanced ungated lung cancer screening chest computed tomography (CT). We included 578 lung cancer screening trial participants who were examined by CT twice within 3 months to follow indeterminate pulmonary nodules. On these CTs, AVC and MC were measured in cubic millimetres. One hundred CTs were examined by five observers to determine the inter-observer variability. Reliability was assessed by kappa statistics (κ) and intra-class correlation coefficients (ICCs). Variability was expressed as the mean difference ± standard deviation (SD). Inter-examination reliability was excellent for AVC (κ = 0.94, ICC = 0.96) and MC (κ = 0.95, ICC = 0.90). Inter-examination variability was 12.7 ± 118.2 mm3 for AVC and 31.5 ± 219.2 mm3 for MC. Inter-observer reliability ranged from κ = 0.68 to κ = 0.92 for AVC and from κ = 0.20 to κ = 0.66 for MC. Inter-observer ICC was 0.94 for AVC and ranged from 0.56 to 0.97 for MC. Inter-observer variability ranged from -30.5 ± 252.0 mm3 to 84.0 ± 240.5 mm3 for AVC and from -95.2 ± 210.0 mm3 to 303.7 ± 501.6 mm3 for MC. AVC can be quantified with excellent reliability on ungated unenhanced low-dose chest CT, but manual detection of MC can be subject to substantial inter-observer variability. Lung cancer screening CT may be used for detection and quantification of cardiac valve calcifications. (orig.)

  3. Impact of high-fat, low-carbohydrate diet on myocardial substrate oxidation, insulin sensitivity, and cardiac function after ischemia-reperfusion.

    Science.gov (United States)

    Liu, Jian; Wang, Peipei; Douglas, Samuel L; Tate, Joshua M; Sham, Simon; Lloyd, Steven G

    2016-07-01

    High-fat, low-carbohydrate Diet (HFLCD) impairs the myocardial response to ischemia-reperfusion, but the underlying mechanisms remain elusive. We sought to determine the magnitude of diet-induced alterations in intrinsic properties of the myocardium (including insulin sensitivity and substrate oxidation) and circulating substrate and insulin differences resulting from diet, leading to this impaired response. Rats were fed HFLCD (60% kcal from fat/30% protein/10% carbohydrate) or control diet (CONT) (16%/19%/65%) for 2 wk. Isolated hearts underwent global low-flow ischemia followed by reperfusion (I/R). Carbon-13 NMR spectroscopy was used to determine myocardial substrate TCA cycle entry. Myocardial insulin sensitivity was assessed as dose-response of Akt phosphorylation. There was a significant effect of HFLCD and I/R with both these factors leading to an increase in free fatty acid (FFA) oxidation and a decrease in carbohydrate or ketone oxidation. Following I/R, HFLCD led to decreased ketone and increased FFA oxidation; the recovery of left ventricular (LV) function was decreased in HFLCD and was negatively correlated with FFA oxidation and positively associated with ketone oxidation. HFLCD also resulted in reduced insulin sensitivity. Under physiologic ranges, there were no direct effects of buffer insulin and ketone levels on oxidation of any substrate and recovery of cardiac function after I/R. An insulin-ketone interaction exists for myocardial substrate oxidation characteristics. We conclude that the impaired recovery of function after ischemia-reperfusion with HFLCD is largely due to intrinsic diet effects on myocardial properties, rather than to diet effect on circulating insulin or substrate levels. PMID:27199129

  4. Cardiac valve calcifications on low-dose unenhanced ungated chest computed tomography: inter-observer and inter-examination reliability, agreement and variability

    Energy Technology Data Exchange (ETDEWEB)

    Hamersvelt, Robbert W. van; Willemink, Martin J.; Takx, Richard A.P.; Eikendal, Anouk L.M.; Budde, Ricardo P.J.; Leiner, Tim; Jong, Pim A. de [University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands); Mol, Christian P.; Isgum, Ivana [University Medical Center Utrecht, Image Sciences Institute, Utrecht (Netherlands)

    2014-07-15

    To determine inter-observer and inter-examination variability for aortic valve calcification (AVC) and mitral valve and annulus calcification (MC) in low-dose unenhanced ungated lung cancer screening chest computed tomography (CT). We included 578 lung cancer screening trial participants who were examined by CT twice within 3 months to follow indeterminate pulmonary nodules. On these CTs, AVC and MC were measured in cubic millimetres. One hundred CTs were examined by five observers to determine the inter-observer variability. Reliability was assessed by kappa statistics (κ) and intra-class correlation coefficients (ICCs). Variability was expressed as the mean difference ± standard deviation (SD). Inter-examination reliability was excellent for AVC (κ = 0.94, ICC = 0.96) and MC (κ = 0.95, ICC = 0.90). Inter-examination variability was 12.7 ± 118.2 mm{sup 3} for AVC and 31.5 ± 219.2 mm{sup 3} for MC. Inter-observer reliability ranged from κ = 0.68 to κ = 0.92 for AVC and from κ = 0.20 to κ = 0.66 for MC. Inter-observer ICC was 0.94 for AVC and ranged from 0.56 to 0.97 for MC. Inter-observer variability ranged from -30.5 ± 252.0 mm{sup 3} to 84.0 ± 240.5 mm{sup 3} for AVC and from -95.2 ± 210.0 mm{sup 3} to 303.7 ± 501.6 mm{sup 3} for MC. AVC can be quantified with excellent reliability on ungated unenhanced low-dose chest CT, but manual detection of MC can be subject to substantial inter-observer variability. Lung cancer screening CT may be used for detection and quantification of cardiac valve calcifications. (orig.)

  5. Oil output's changing fortunes

    International Nuclear Information System (INIS)

    The Petroleum Economist, previously the Petroleum Press Service, has been making annual surveys of output levels of petroleum in all the oil-producing countries since its founding in 1934. This article documents trends and changes in the major oil-producing countries output from 1934 until the present. This analysis is linked with the political and historical events accompanying these changes, notably the growth of Middle Eastern oil production, the North Sea finds and most recently, Iraq's invasion of Kuwait in 1990. (UK)

  6. High Thoracic Epidural Analgesia as an Adjunct to General Anesthesia is Associated with Better Outcome in Low-to-Moderate Risk Cardiac Surgery Patients

    DEFF Research Database (Denmark)

    Stenger, Michael; Fabrin, Anja; Schmidt, Henrik; Greisen, Jacob; Erik Mortensen, Poul; Jakobsen, Carl-Johan

    2013-01-01

    The purpose of this study was to evaluate the addition of high thoracic epidural analgesia (HTEA) to general anesthesia in cardiac surgery patients to enhance the fast-track and improvement in outcome.......The purpose of this study was to evaluate the addition of high thoracic epidural analgesia (HTEA) to general anesthesia in cardiac surgery patients to enhance the fast-track and improvement in outcome....

  7. Research, development, and testing of a prototype two-stage low-input rate oil burner for variable output heating system applications

    Energy Technology Data Exchange (ETDEWEB)

    Krajewski, R.F.; Butcher, T.A. [Brookhaven National Labs., Upton, NY (United States)

    1997-09-01

    The use of a Two-Stage Fan Atomized Oil Burner (TSFAB) in space and water heating applications will have dramatic advantages in terms of it`s potential for a high Annual Fuel Utilization Efficiency (AFUE) and/or Energy Factor (EF) rating for the equipment. While demonstrations of a single rate burner in an actual application have already yielded sufficient confidence that space and domestic heating loads can be met at a single low firing rate, this represents only a narrow solution to the diverse nature of building space heating and domestic water loads that the industry must address. The mechanical development, proposed control, and testing of the Two-Stage burner is discussed in terms of near term and long term goals.

  8. Serial Input Output

    Energy Technology Data Exchange (ETDEWEB)

    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

  9. 脉搏指示连续心排血量监测技术救治重症胰腺炎并发急性呼吸窘迫综合征患儿二例%Pulse indicator continuous cardiac output measurement-guided treatment aids two pediatric patients with severe acute pancreatitis complicated with acute respiratory distress syndrome

    Institute of Scientific and Technical Information of China (English)

    颜卫源; 王丽杰

    2014-01-01

    Objective To evaluate the clinical value of the pulse indicator continuous cardiac output (PiCCO) system in patients with severe acute pancreatitis (SAP) complicated with acute respiratory distress syndrome (ARDS).Method Two cases of SAP with ARDS were monitored using PiCCO during comprehensive management in the Pediatric Intensive Care Unit (PICU) of Shengjing Hospital,China Medical University.To guide fluid management,the cardiac index (CI) was measured to assess cardiac function,the global end-diastolic volume index (GEDVI) was used to evaluate cardiac preload,and the extravascular lung water index (EVLWI) was used to evaluate the pulmonary edema.Result Case 1 was diagnosed with type L2 acute lymphoblastic leukemia (intermediate risk) and received the sixth maintenance phases of chemotherapy this time.After a 1-week dosage of chemotherapeutic drugs (pegaspargase and mitoxantrone),he suffered SAP combined with ARDS.Except comprehensive treatment (life supporting,antibiotic,etc.) and applying continuous veno-venous hemodiafiltration (CVVHDF) to remove inflammatory mediators.PiCCO monitor was utilized to guide fluid management.During the early stage of PiCCO monitoring,the patient showed no significant manifestations of pulmonary edema in the bedside chest X-ray (bedside ultrasound showed left pleural effusion),and had an oxygenation index 223 mmHg (1 mmHg =0.133 kPa),GEDVI 450 ml/m2,and ELVWI 7 ml/kg.We increased cardiac output to increase tissue perfusion and dehydration speed of CVVHDF was set at 70 ml/h.Two hours later,GEDVI significantly increased to 600 ml/m2 and ELVWI significantly increased to 10 ml/kg,the oxygenation index declined to 155 mmHg,the bedside chest X-ray showed a significant decrease of permeability (right lung) and PEEP was adjusted to 5 cmH2O (1 cmH2O =0.098 kPa),indicating circulating overload.ARDS subsequently occurred,upon which the fluid infusion was halted,the dehydration rate of CVVHDF raised (adjusted to 100-200 ml/h).On day 3 in the

  10. Cardiac conduction system

    Science.gov (United States)

    The cardiac conduction system is a group of specialized cardiac muscle cells in the walls of the heart that send signals ... to contract. The main components of the cardiac conduction system are the SA node, AV node, bundle ...

  11. Socially differentiated cardiac rehabilitation

    DEFF Research Database (Denmark)

    Meillier, Lucette Kirsten; Nielsen, Kirsten Melgaard; Larsen, Finn Breinholt;

    2012-01-01

    recruitment and participation among low educated and socially vulnerable patients must be addressed to lower inequality in post-MI health. Our aim was to improve referral, attendance, and adherence rates among socially vulnerable patients by systematic screening and by offering a socially differentiated...... standard rehabilitation programme (SRP). If patients were identified as socially vulnerable, they were offered an extended version of the rehabilitation programme (ERP). Excluded patients were offered home visits by a cardiac nurse. Concordance principles were used in the individualised programme elements......%. Patients were equally distributed to the SRP and the ERP. No inequality was found in attendance and adherence among referred patients. Conclusions: It seems possible to overcome unequal referral, attendance, and adherence in cardiac rehabilitation by organisation of systematic screening and social...

  12. 高输入输出变比的两级式DC/DC变换器%Two-stage DC/DC converter for high voltage input low voltage output case

    Institute of Scientific and Technical Information of China (English)

    张玄; 宁国云; 毛康宇; 黄声华

    2011-01-01

    Two-stage converter is more applicable than the single-stage converter for high voltage input low voltage output case. A Buck + LLC resonance full bridge topology was introduced in this paper. The operation principles and the characteristics of the LLC resonance full bridge topology were introduced. Then based on stability analysis of the two-stage converters high efficiency was achieved via rationally choosing the output voltage of front stage Buck circuit, the transformer turn ratio and resonance elements values of the end stage LLC resonance full bridge circuit. Finally, a 1 kW converter was designed, which had 210-270 V input and 27 V output. Then the experiment result was given.%两级式变换器比单级式变换器更适合应用在输入输出变比较高的DC/DC变换场合.研究了一种Buck+LLC谐振全桥的电路拓扑,阐述了LLC谐振全桥的原理和特性,在分析了这种两级变换器的稳定性基础上,通过合理选取前级Buck电路的输出电压、后级LLC谐振全桥变压器变比和谐振元件参数,提高了两级变换的效率.基于上述分析,采用该拓扑结构试制了一台功率1kW,210-270 V输入,27V输出的原理样机,并给出了实验结果.

  13. EFFECTIVENESS OF LOW INTENSITY EXERCISES ON SIX MINUTE WALK DISTANCE AND HAEMODYNAMIC VARIABLES IN CABG AND VALVE REPLACEMENT PATIENTS DURING PHASE 1 CARDIAC REHABILITATION IN A TERTIARY CARE SETUP: A COMPARATIVE STUDY

    Directory of Open Access Journals (Sweden)

    Renu B.Pattanshetty

    2014-10-01

    Full Text Available BACKGROUND AND OBJECTIVES: Cardiovascular diseases are common and devastating health problem in India. The most common is the coronary artery diseases and heart valve diseases. Cardiac rehabilitation programme is an essential, useful and safe part of the care for patients with cardiovascular disease. The present study was under taken to compare the effectiveness of low level intensity exercises on haemodynamic variables and functional capacity in subjects enrolled in phase 1 cardiac rehabilitation. MATERIAL AND METHODS: Thirty (30 adult subjects both male and female comprising of CABG (15 subjects and valve replacement (15 subjects were included. Low intensity exercises were given to both groups which included range of motion exercises, stretching and minimal strength training. Haemodynamic variables and six minute walk distance were assessed pre and post invention in all the subjects. RESULTS: The study demonstrated BMI to be lower valve replacement group than CABG group (p = 0.008. Ejection fraction(% were higher in valve replacement subjects compared to CABG subjects (p = 0.027. Significant mean differences were noted in the heart rate between both the groups. (p = 0.045. There was a significant improvement in the six minute walk distance (p = 0.048 in both groups. CONCLUSION: Low intensity exercises demonstrated improvements in heart rate and functional capacity in subjects with CABG and valve replacement in phase I cardiac rehabilitation.

  14. Acute kidney injury after cardiac arrest

    OpenAIRE

    Tujjar, Omar; Mineo, Giulia; Dell’Anna, Antonio; Poyatos-Robles, Belen; Donadello, Katia; Scolletta, Sabino; Vincent, Jean-Louis; Taccone, Fabio Silvio

    2015-01-01

    Introduction The aim of this study was to evaluate the incidence and determinants of AKI in a large cohort of cardiac arrest patients. Methods We reviewed all patients admitted, for at least 48 hours, to our Dept. of Intensive Care after CA between January 2008 and October 2012. AKI was defined as oligo-anuria (daily urine output

  15. Amelioration of cardiac function and activation of anti-inflammatory vasoactive peptides expression in the rat myocardium by low level laser therapy.

    Directory of Open Access Journals (Sweden)

    Martha Trindade Manchini

    Full Text Available Low-level laser therapy (LLLT has been used as an anti-inflammatory treatment in several disease conditions, even when inflammation is a secondary consequence, such as in myocardial infarction (MI. However, the mechanism by which LLLT is able to protect the remaining myocardium remains unclear. The present study tested the hypothesis that LLLT reduces inflammation after acute MI in female rats and ameliorates cardiac function. The potential participation of the Renin-Angiotensin System (RAS and Kallikrein-Kinin System (KKS vasoactive peptides was also evaluated. LLLT treatment effectively reduced MI size, attenuated the systolic dysfunction after MI, and decreased the myocardial mRNA expression of interleukin-1 beta and interleukin-6 in comparison to the non-irradiated rat tissue. In addition, LLLT treatment increased protein and mRNA levels of the Mas receptor, the mRNA expression of kinin B2 receptors and the circulating levels of plasma kallikrein compared to non-treated post-MI rats. On the other hand, the kinin B1 receptor mRNA expression decreased after LLLT. No significant changes were found in the expression of vascular endothelial growth factor (VEGF in the myocardial remote area between laser-irradiated and non-irradiated post-MI rats. Capillaries density also remained similar between these two experimental groups. The mRNA expression of the inducible nitric oxide synthase (iNOS was increased three days after MI, however, this effect was blunted by LLLT. Moreover, endothelial NOS mRNA content increased after LLLT. Plasma nitric oxide metabolites (NOx concentration was increased three days after MI in non-treated rats and increased even further by LLLT treatment. Our data suggest that LLLT diminishes the acute inflammation in the myocardium, reduces infarct size and attenuates left ventricle dysfunction post-MI and increases vasoactive peptides expression and nitric oxide (NO generation.

  16. Amelioration of cardiac function and activation of anti-inflammatory vasoactive peptides expression in the rat myocardium by low level laser therapy.

    Science.gov (United States)

    Manchini, Martha Trindade; Serra, Andrey Jorge; Feliciano, Regiane dos Santos; Santana, Eduardo Tadeu; Antônio, Ednei Luis; de Tarso Camillo de Carvalho, Paulo; Montemor, Jairo; Crajoinas, Renato Oliveira; Girardi, Adriana Castello Costa; Tucci, Paulo José Ferreira; Silva, José Antônio

    2014-01-01

    Low-level laser therapy (LLLT) has been used as an anti-inflammatory treatment in several disease conditions, even when inflammation is a secondary consequence, such as in myocardial infarction (MI). However, the mechanism by which LLLT is able to protect the remaining myocardium remains unclear. The present study tested the hypothesis that LLLT reduces inflammation after acute MI in female rats and ameliorates cardiac function. The potential participation of the Renin-Angiotensin System (RAS) and Kallikrein-Kinin System (KKS) vasoactive peptides was also evaluated. LLLT treatment effectively reduced MI size, attenuated the systolic dysfunction after MI, and decreased the myocardial mRNA expression of interleukin-1 beta and interleukin-6 in comparison to the non-irradiated rat tissue. In addition, LLLT treatment increased protein and mRNA levels of the Mas receptor, the mRNA expression of kinin B2 receptors and the circulating levels of plasma kallikrein compared to non-treated post-MI rats. On the other hand, the kinin B1 receptor mRNA expression decreased after LLLT. No significant changes were found in the expression of vascular endothelial growth factor (VEGF) in the myocardial remote area between laser-irradiated and non-irradiated post-MI rats. Capillaries density also remained similar between these two experimental groups. The mRNA expression of the inducible nitric oxide synthase (iNOS) was increased three days after MI, however, this effect was blunted by LLLT. Moreover, endothelial NOS mRNA content increased after LLLT. Plasma nitric oxide metabolites (NOx) concentration was increased three days after MI in non-treated rats and increased even further by LLLT treatment. Our data suggest that LLLT diminishes the acute inflammation in the myocardium, reduces infarct size and attenuates left ventricle dysfunction post-MI and increases vasoactive peptides expression and nitric oxide (NO) generation. PMID:24991808

  17. Three-dimensional display and measurement of cardiac dynamic indexes from MR images

    International Nuclear Information System (INIS)

    The cardiac dynamic index, to which such variables as cardiac output, ejection fraction, and wall motion contribute, is routinely determined using various modalities such as angiography, radionuclide imaging, US, and x-ray CT. Each of these modalities, however, has some disadvantages in regard to evaluating the cardiac dynamic index. The authors have obtained precise multidirectional projection images of the heart by means of computer graphics and reformatted data of cardiac MR images obtained with cardiac gating. The contiguous coronal MR images of the heart are made at an interimage distance of 5 mm. In each section, five or six cardiac images can be obtained, depending on the systolic or diastolic phase. These images are stored in a computer, and a three-dimensional display of the heart with biocular observation and with multiplex holograms is made possible with computer graphics. Three-dimensional measurement of the cardiac index is now being attempted, including cardiac output, ejection fraction, and wall motion

  18. Literature survey on epidemiology and pathology of cardiac fibroma

    Directory of Open Access Journals (Sweden)

    Torimitsu Suguru

    2012-03-01

    Full Text Available Abstract Background Although cardiac fibroma has been regarded as benign tumor, it presents various symptoms and may lead to death. Unfortunately, only a few studies have reported the epidemiology, embryology, and histopathology of the tumor, and the factors predicting poorer outcome are still obscured. Methods In July 2011 we searched for English and Japanese cases of cardiac fibroma using the PubMed and IgakuChuoZasshi databases. We then extracted and sampled raw data from the selected publications in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA style as much as was possible. Results Details of a total of 178 patients with cardiac fibroma were retrieved. The mean age was 11.4 years (median: 2.8 years. Tumor sizes ranged from 8.0 to 150.0 mm (mean 53.1 mm. The left ventricle was found to be the most common site associated with the tumor at a rate of 57.3%, followed by the right ventricle, and interventricular septum. The highest mortality was found in patients with septal involvement (58.6%. In all, 111 patients survived among the 160 patients with a recorded outcome. A younger age of the patient at the time of diagnosis was associated with a decreased survival rate. In addition, a significant positive association was found between ages for patients younger than 17 years of age and the diameter of the tumor at the time of diagnosis (r = 0.341, P = 0.006. Conclusions Both the younger age of patients at the time of diagnosis and septal involvement can be regarded as factors significantly indicating a poor prognosis. Furthermore, our statistical analyses support the following hypotheses. First, the high ratio of tumor-to-heart size may generate low cardiac output and therefore lead to poor outcome. Second, the ratio of the sites where cardiac fibroma occurred corresponds with the ratio of the muscular weight of the cardiac chamber. Third, cardiac fibroma involving the interventricular septum more

  19. Cardiac effects of 3-iodothyronamine: a new aminergic system modulating cardiac function.

    Science.gov (United States)

    Chiellini, Grazia; Frascarelli, Sabina; Ghelardoni, Sandra; Carnicelli, Vittoria; Tobias, Sandra C; DeBarber, Andrea; Brogioni, Simona; Ronca-Testoni, Simonetta; Cerbai, Elisabetta; Grandy, David K; Scanlan, Thomas S; Zucchi, Riccardo

    2007-05-01

    3-Iodothyronamine T1AM is a novel endogenous thyroid hormone derivative that activates the G protein-coupled receptor known as trace anime-associated receptor 1 (TAAR1). In the isolated working rat heart and in rat cardiomyocytes, T1AM produced a reversible, dose-dependent negative inotropic effect (e.g., 27+/-5, 51+/-3, and 65+/-2% decrease in cardiac output at 19, 25, and 38 microM concentration, respectively). An independent negative chronotropic effect was also observed. The hemodynamic effects of T1AM were remarkably increased in the presence of the tyrosine kinase inhibitor genistein, whereas they were attenuated in the presence of the tyrosine phosphatase inhibitor vanadate. No effect was produced by inhibitors of protein kinase A, protein kinase C, calcium-calmodulin kinase II, phosphatidylinositol-3-kinase, or MAP kinases. Tissue cAMP levels were unchanged. In rat ventricular tissue, Western blot experiments with antiphosphotyrosine antibodies showed reduced phosphorylation of microsomal and cytosolic proteins after perfusion with synthetic T1AM; reverse transcriptase-polymerase chain reaction experiments revealed the presence of transcripts for at least 5 TAAR subtypes; specific and saturable binding of [125I]T1AM was observed, with a dissociation constant in the low micromolar range (5 microM); and endogenous T1AM was detectable by tandem mass spectrometry. In conclusion, our findings provide evidence for the existence of a novel aminergic system modulating cardiac function. PMID:17284482

  20. Tenure and Output

    OpenAIRE

    Kathryn Shaw; Edward P. Lazear

    2007-01-01

    A key tenet of the theory of human capital is that investment in skills results in higher productivity. The previous literature has estimated the degree of investment in human capital for individuals by looking at individual wage growth as a proxy for productivity growth. In this paper, we have both wage and personal productivity data, and thus are able to measure of the increase in workers' output with tenure. The data is from an autoglass company. Most of production occurs at the individual...

  1. Lithotomy versus jack-knife position on haemodynamic parameters assessed by impedance cardiography during anorectal surgery under low dose spinal anaesthesia: a randomized controlled trial

    OpenAIRE

    Borodiciene, Jurgita; Gudaityte, Jurate; Macas, Andrius

    2015-01-01

    Background Although the prone position providing better exposure for anorectal surgery is required it can cause a reduction of cardiac output and cardiac index. The goal was to compare haemodynamic changes assessed by impedance cardiography during anorectal surgery under low-dose spinal anaesthesia in lithotomy and jack-knife position. Methods The prospective randomized controlled study included 104, ASA I-II adult patients admitted for elective minor anorectal surgery, assigned to be perform...

  2. A Wearable Contactless Sensor Suitable for Continuous Simultaneous Monitoring of Respiration and Cardiac Activity

    Directory of Open Access Journals (Sweden)

    Gaetano D. Gargiulo

    2015-01-01

    Full Text Available A reliable system that can simultaneously and accurately monitor respiration and cardiac output would have great utility in healthcare applications. In this paper we present a novel approach to creating such a system. This noninvasive, low power, low cost, contactless sensor is suitable for continuous monitoring of respiration (tidal volume and cardiac stroke volume. Furthermore, it is capable of delivering this data in true volume (i.e., mL. The current embodiment, specifically designed for sleep monitoring applications, requires only 100 mW when powered by a 4.8 V battery pack and is based on the use of a single electroresistive band embedded in a T-shirt. Here, we describe the implementation of the device, explaining the rational and design choices for the electronic circuit and the physical garment together with the preliminary tests performed using one volunteer subject. Comparison of the device with a commercially available spirometer demonstrates that tidal volume can be monitored over extended periods with a precision of ±10%. We further demonstrate the utility of the device to measure cardiac output and respiration effort.

  3. The effect of age on the relationship between cardiac and vascular function

    OpenAIRE

    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 car...

  4. Cardiac MRI in Athletes

    NARCIS (Netherlands)

    Luijkx, T.

    2012-01-01

    Cardiac magnetic resonance imaging (CMR) is often used in athletes to image cardiac anatomy and function and is increasingly requested in the context of screening for pathology that can cause sudden cardiac death (SCD). In this thesis, patterns of cardiac adaptation to sports are investigated with C

  5. Low-dose, time-resolved, contrast-enhanced 3D MR angiography in cardiac and vascular diseases: correlation to high spatial resolution 3D contrast-enhanced MRA

    Energy Technology Data Exchange (ETDEWEB)

    Krishnam, M.S. [Department of Radiological Sciences, University of California at Los Angeles, Los Angeles, CA (United States)], E-mail: mkrishnam@mednet.ucla.edu; Tomasian, A.; Lohan, D.G.; Tran, L.; Finn, J.P.; Ruehm, S.G. [Department of Radiological Sciences, University of California at Los Angeles, Los Angeles, CA (United States)

    2008-07-15

    Aim: To evaluate the effectiveness of low-dose, contrast-enhanced, time-resolved, three-dimensional (3D) magnetic resonance (MR) angiography (TR-MRA) in the assessment of various cardiac and vascular diseases, and to compare the results with high-resolution contrast-enhanced MRA (CE-MRA). Materials and Methods: Thirty consecutive patients underwent contrast-enhanced 3D TR-MRA and high spatial resolution 3D CE-MRA for evaluation of cardiac and thoracic vascular diseases at 1.5 T, and neurovascular, abdominal and peripheral vascular diseases at 3 T. Gadolinium-based contrast medium was administered at a constant dose of 5 ml for TR-MRA, and 20 ml (lower extremity 30 ml) for CE-MRA. Two readers evaluated image quality using a four-point scale (from 0 = excellent to 3 = non-diagnostic), artefacts and findings on both datasets. Interobserver variability was tested with kappa coefficient. Results: The overall image quality for TR-MRA was in the diagnostic range (median 0, range 0-1; k = 0.74). Readers demonstrated important additional dynamic information on TR-MRA in 28 of 30 patients (k = 0.84). Confident evaluation of organ perfusion (n = 23), arteriovenous malformation/fistula flow patterns (n = 7), exclusion of intra-cardiac shunts (n = 6), and assessment of stent and conduit patency (n = 5) were performed by both readers using TR-MRA. Readers demonstrated fine vascular details with higher confidence in 10 patients on CE-MRA. Using CE-MRA, Reader 1 and 2 depicted anatomical details in 6 and 5 patients, respectively, only on CE-MRA. Conclusion: Low-dose TR-MRA yields rapid and important functional and anatomical information in patients with cardiac and vascular diseases. Due to limited spatial resolution, TR-MRA is inferior to CE-MRA in demonstrating fine vascular details.

  6. Baixa dosagem de óxido de cromo para estimativa da produção fecal em bovinos Low level of chromium oxide to estimate faecal output in cattle

    Directory of Open Access Journals (Sweden)

    Henrique Mendonça Nunes Ribeiro Filho

    2008-12-01

    Full Text Available Foi avaliado o uso de baixa dosagem de óxido de cromo (Cr2O3 incorporado em um alimento concentrado para estimativa da produção fecal (PF em bovinos. Para tanto, foram conduzidos quatro ensaios de digestibilidade in vivo utilizando quatro novilhos com peso vivo médio de 214±31kg, recebendo ad libitum no cocho azevém anual (Lolium multiflorum Lam. cortado verde. Aproximadamente 200g de ração contendo 5g kg-1 do indicador foi fornecida diariamente durante 12 dias, sendo feito a coleta de dados e amostras nos últimos cinco dias de cada período. A PF foi medida com o uso de sacolas de coleção total ou estimada com base na concentração do indicador em amostras fecais coletadas duas vezes ao dia (8 e 16h ou a intervalos de duas horas entre 8 e 22h. A concentração média de cromo nas amostras coletadas às 8 e 16h (445mg kg-1 foi semelhante à média geral de todos os horários (447mg kg-1. O grau de recuperação fecal (GR do indicador aumentou linearmente, de aproximadamente 40% para em torno de 80%, com o aumento da concentração fecal de cromo até esta última atingir um valor em torno de 250mg kg-1 de MO. Quando a concentração de cromo nas fezes foi superior a este valor o GR se manteve relativamente constante, em média 76%. A produção fecal foi superestimada pelo indicador em até 35% quando não corrigido para o GR. Quando corrigido para a recuperação fecal, as estimativas de produção fecal de MO estimadas foram similares às observadas. A excreção fecal de bovinos alimentados com azevém pode ser acuradamente estimada com o uso de baixa dosagem de óxido de cromo incorporado em uma ração peletizada concomitante à coleta de duas amostragens diárias de fezes.The aim of this research was to evaluate the use of a low level of chromium oxide (Cr2O3 incorporated into the concentrate ration to estimate faecal output (FO in cattle. Four in vivo digestibility essays were conducted using four steers with live weights of

  7. Gated SPECT evaluation of left ventricular function using a CZT camera and a fast low-dose clinical protocol: comparison to cardiac magnetic resonance imaging

    International Nuclear Information System (INIS)

    CZT technology allows ultrafast low-dose myocardial scintigraphy but its accuracy in assessing left ventricular function is still to be defined. The study group comprised 55 patients (23 women, mean age 63 ± 9 years) referred for myocardial perfusion scintigraphy. The patients were studied at rest using a CZT camera (Discovery NM530c; GE Healthcare) and a low-dose 99mTc-tetrofosmin clinical protocol (mean dose 264 ± 38 MBq). Gated SPECT imaging was performed as a 6-min list-mode acquisition, 15 min after radiotracer injection. Images were reformatted (8-frame to 16-frame) using Lister software on a Xeleris workstation (GE Healthcare) and then reconstructed with a dedicated iterative algorithm. Analysis was performed using Quantitative Gated SPECT (QGS) software. Within 2 weeks patients underwent cardiac magnetic resonance imaging (cMRI, 1.5-T unit CVi; GE Healthcare) using a 30-frame acquisition protocol and dedicated software for analysis (MASS 6.1; Medis). The ventricular volumes obtained with 8-frame QGS showed excellent correlations with the cMRI volumes (end-diastolic volume (EDV), r = 0.90; end-systolic volume (ESV), r = 0.94; p < 0.001). However, QGS significantly underestimated the ventricular volumes (mean differences: EDV, -39.5 ± 29 mL; ESV, -15.4 ± 22 mL; p < 0.001). Similarly, the ventricular volumes obtained with 16-frame QGS showed an excellent correlations with the cMRI volumes (EDV, r = 0.92; ESV, r = 0.95; p < 0.001) but with significant underestimations (mean differences: EDV, -33.2 ± 26 mL; ESV, -17.9 ± 20 mL; p < 0.001). Despite significantly lower values (47.9 ± 16 % vs. 51.2 ± 15 %, p < 0.008), 8-frame QGS mean ejection fraction (EF) was closely correlated with the cMRI values (r = 0.84, p < 0.001). The mean EF with 16-frame QGS showed the best correlation with the cMRI values (r = 0.91, p < 0.001) and was similar to the mean cMRI value (49.6 ± 16 %, p not significant). Regional analysis showed a good correlation between both 8-frame

  8. Gated SPECT evaluation of left ventricular function using a CZT camera and a fast low-dose clinical protocol: comparison to cardiac magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Giorgetti, Assuero; Masci, Pier Giorgio; Marras, Gavino; Gimelli, Alessia; Genovesi, Dario; Lombardi, Massimo [Fondazione CNR/Regione Toscana ' ' G. Monasterio' ' , Pisa (Italy); Rustamova, Yasmine K. [Azerbaijan Medical University, Department of internal medicine Central Customs Hospital, Baku (Azerbaijan); Marzullo, Paolo [Istituto di Fisiologia Clinica del CNR, Pisa (Italy)

    2013-12-15

    CZT technology allows ultrafast low-dose myocardial scintigraphy but its accuracy in assessing left ventricular function is still to be defined. The study group comprised 55 patients (23 women, mean age 63 {+-} 9 years) referred for myocardial perfusion scintigraphy. The patients were studied at rest using a CZT camera (Discovery NM530c; GE Healthcare) and a low-dose {sup 99m}Tc-tetrofosmin clinical protocol (mean dose 264 {+-} 38 MBq). Gated SPECT imaging was performed as a 6-min list-mode acquisition, 15 min after radiotracer injection. Images were reformatted (8-frame to 16-frame) using Lister software on a Xeleris workstation (GE Healthcare) and then reconstructed with a dedicated iterative algorithm. Analysis was performed using Quantitative Gated SPECT (QGS) software. Within 2 weeks patients underwent cardiac magnetic resonance imaging (cMRI, 1.5-T unit CVi; GE Healthcare) using a 30-frame acquisition protocol and dedicated software for analysis (MASS 6.1; Medis). The ventricular volumes obtained with 8-frame QGS showed excellent correlations with the cMRI volumes (end-diastolic volume (EDV), r = 0.90; end-systolic volume (ESV), r = 0.94; p < 0.001). However, QGS significantly underestimated the ventricular volumes (mean differences: EDV, -39.5 {+-} 29 mL; ESV, -15.4 {+-} 22 mL; p < 0.001). Similarly, the ventricular volumes obtained with 16-frame QGS showed an excellent correlations with the cMRI volumes (EDV, r = 0.92; ESV, r = 0.95; p < 0.001) but with significant underestimations (mean differences: EDV, -33.2 {+-} 26 mL; ESV, -17.9 {+-} 20 mL; p < 0.001). Despite significantly lower values (47.9 {+-} 16 % vs. 51.2 {+-} 15 %, p < 0.008), 8-frame QGS mean ejection fraction (EF) was closely correlated with the cMRI values (r = 0.84, p < 0.001). The mean EF with 16-frame QGS showed the best correlation with the cMRI values (r = 0.91, p < 0.001) and was similar to the mean cMRI value (49.6 {+-} 16 %, p not significant). Regional analysis showed a good

  9. Cardiac perception and cardiac control. A review.

    Science.gov (United States)

    Carroll, D

    1977-12-01

    The evidence regarding specific cardiac perception and discrimination, and its relationship to voluntary cardiac control, is critically reviewed. Studies are considered in three sections, depending on the method used to assess cardiac perception: questionnaire assessment, discrimination procedures, and heartbeat tracking. The heartbeat tracking procedure would appear to suffer least from interpretative difficulties. Recommendations are made regarding the style of analysis used to assess heartbeat perception in such tracking tasks. PMID:348240

  10. A new nonlinear output tracking controller via output-feedback

    Institute of Scientific and Technical Information of China (English)

    Yun ZHANG; Yungang LIU; Yuqin DING

    2006-01-01

    In this paper, the output tracking control is investigated for a class of nonlinear systems when only output is available for feedback. Based on the multivariable analog of circle criterion, an observer is first introduced. Then, the observer-based output tracking controller is constructively designed by using the integral backstepping approach together with completing square. It is shown that, under relatively mild conditions, all the closed-loop signals are uniformly bounded.Meanwhile the system output asymptotically tracks the desired output. A simulation example is given to illustrate the effectiveness of the theoretical results.

  11. The influence of anatomical and physiological parameters on the interference voltage at the input of unipolar cardiac pacemakers in low frequency electric fields

    Science.gov (United States)

    Joosten, S.; Pammler, K.; Silny, J.

    2009-02-01

    The problem of electromagnetic interference of electronic implants such as cardiac pacemakers has been well known for many years. An increasing number of field sources in everyday life and occupational environment leads unavoidably to an increased risk for patients with electronic implants. However, no obligatory national or international safety regulations exist for the protection of this patient group. The aim of this study is to find out the anatomical and physiological worst-case conditions for patients with an implanted pacemaker adjusted to unipolar sensing in external time-varying electric fields. The results of this study with 15 volunteers show that, in electric fields, variation of the interference voltage at the input of a cardiac pacemaker adds up to 200% only because of individual factors. These factors should be considered in human studies and in the setting of safety regulations.

  12. Output gaps: uses and limitation

    OpenAIRE

    Roc Armenter

    2011-01-01

    The concept of resource slack is central to understanding the dynamics between employment, output, and inflation. But what amount of slack is consistent with price stability? To answer this question, economists define baseline values for unemployment and output known as the natural rate of unemployment and potential output. The concepts of output and employment gaps can be useful to economists in several ways. First, they often guide the inflation forecasts of Federal Reserve staff and other ...

  13. Calmodulin 2 Mutation N98S Is Associated with Unexplained Cardiac Arrest in Infants Due to Low Clinical Penetrance Electrical Disorders

    Science.gov (United States)

    Jiménez-Jáimez, Juan; Palomino Doza, Julián; Ortega, Ángeles; Macías-Ruiz, Rosa; Perin, Francesca; Rodríguez-Vázquez del Rey, M. Mar; Ortiz-Genga, Martín; Monserrat, Lorenzo; Barriales-Villa, Roberto; Blanca, Enrique; Álvarez, Miguel; Tercedor, Luis

    2016-01-01

    Background Calmodulin 1, 2 and 3 (CALM) mutations have been found to cause cardiac arrest in children at a very early age. The underlying aetiology described is long QT syndrome (LQTS), catecholaminergic polymorphic ventricular tachycardia (CPVT) and idiopathic ventricular fibrillation (IVF). Little phenotypical data about CALM2 mutations is available. Objectives The aim of this paper is to describe the clinical manifestations of the Asn98Ser mutation in CALM2 in two unrelated children in southern Spain with apparently unexplained cardiac arrest/death. Methods Two unrelated children aged 4 and 7, who were born to healthy parents, were studied. Both presented with sudden cardiac arrest. The first was resuscitated after a VF episode, and the second died suddenly. In both cases the baseline QTc interval was within normal limits. Peripheral blood DNA was available to perform targeted gene sequencing. Results The surviving 4-year-old girl had a positive epinephrine test for LQTS, and polymorphic ventricular ectopic beats were seen on a previous 24-hour Holter recording from the deceased 7-year-old boy, suggestive of a possible underlying CPVT phenotype. A p.Asn98Ser mutation in CALM2 was detected in both cases. This affected a highly conserved across species residue, and the location in the protein was adjacent to critical calcium binding loops in the calmodulin carboxyl-terminal domain, predicting a high pathogenic effect. Conclusions Human calmodulin 2 mutation p.Asn98Ser is associated with sudden cardiac death in childhood with a variable clinical penetrance. Our results provide new phenotypical information about clinical behaviour of this mutation. PMID:27100291

  14. Mongolia; Measuring the Output Gap

    OpenAIRE

    Julia Bersch; Tara M. Sinclair

    2011-01-01

    This paper compares the output gap estimates for Mongolia based on a number of different methods. Special attention is paid to the substantial role of mining in the Mongolian economy. We find that a Blanchard and Quah-type joint model of output and inflation provides a more robust estimate of the output gap for Mongolia than the traditional statistical decompositions.

  15. Methods of increasing net work output of organic Rankine cycles for low-grade waste heat recovery with a detailed analysis using a zeotropic working fluid mixture and scroll expander

    Science.gov (United States)

    Woodland, Brandon Jay

    performance to cost ratio of this machine lends significant credence to the economic viability of small-scale, low-temperature ORCs. The experimental campaign covered two heat source temperatures, the full range of pump and expander speeds, a full range of heat source and heat sink fluid flow rates, and various charge levels for the three working fluids. This resulted in 366 steady-state measurements. The steady state measurements are used to develop a detailed ORC model. The model is based on multi-fluid performance maps for the pump and expander and a robust moving-boundary heat exchanger model. It is validated against the measured data and predicts the net power output of the tested ORC with a mean absolute percent error of 7.16%. Comparisons made with the detailed model confirm the predictions of the design-stage model. Using a conservative estimate of the condenser fan power, 19.1% improvement of the ZRC over the baseline ORC is indicated for a source temperature of 80 °C. For a 100 °C source temperature, 13.8% improvement is indicated. A key feature of the detailed ORC model is that it calculates the charge inventory of the working fluid in each heat exchanger and line set. Total system charge can also be specified as a model input. The model can represent the total charge well for R134a at low measured charge levels. As the measured charge level increases, the model becomes less accurate. Reasons for the deviation of the model at higher charge are investigated. It is expected that a charge tuning scheme could be employed to improve the accuracy of model-predicted charge.

  16. Débito cardíaco e fração de ejeção fetal por meio do spatio-temporal image correlation (STIC: comparação entre fetos masculinos e femininos Fetal cardiac output and ejection fraction by spatio-temporal image correlation (STIC: comparison between male and female fetuses

    Directory of Open Access Journals (Sweden)

    Christiane Simioni

    2012-06-01

    Full Text Available OBJETIVO: Comparar do débito cardíaco (DC e a fração de ejeção (FE do coração de fetos masculinos e femininos obtidos por meio da ultrassonografia tridimensional, utilizando o spatio-temporal image correlation (STIC. MÉTODOS: Realizou-se um estudo de corte transversal com 216 fetos normais, entre 20 a 34 semanas de gestação, sendo 108 masculinos e 108 femininos. Os volumes ventriculares no final da sístole e diástole foram obtidos por meio do STIC, sendo as avaliações volumétricas realizadas pelo virtual organ computer-aided analysis (VOCAL com rotação de 30º. Para o cálculo do DC utilizou-se a fórmula: DC= volume sistólico/frequência cardíaca fetal, enquanto que para a FE utilizou-se a fórmula: FE= volume sistólico/volume diastólico final. O DC (combinado, feminino e masculino e a FE (masculina e feminina foram comparadas utilizando-se o teste t não pareado e ANCOVA. Foram criados gráficos de dispersão com os percentis 5, 50 e 95. RESULTADOS: A média do DC combinado, DC direito, DC esquerdo, FE direita e FE esquerda, para feminino e masculino, foram 240,07 mL/min; 122,67 mL/min; 123,40 mL/min; 72,84%; 67,22%; 270,56 mL/min; 139,22 mL/min; 131,34 mL/min; 70,73% e 64,76%, respectivamente; sem diferença estatística (P> 0,05. CONCLUSÕES: O DC e a FE fetal obtidos por meio da ultrassonografia tridimensional (STIC não apresentaram diferença significativa em relação ao gênero.OBJECTIVE: To compare the cardiac output (CO and ejection fraction (EF of the heart of male and female fetuses obtained by 3D-ultrasonography using spatio-temporal image correlation (STIC. METHODS: We conducted a cross-sectional study with 216 normal fetuses, between 20 and 34 weeks of gestation, 108 male and 108 female. Ventricular volumes at the end of systole and diastole were obtained by STIC, and the volumetric assessments performed by the virtual organ computer-aided analysis (VOCAL rotated 30º. To calculate the DC used the formula

  17. What Is Cardiac Rehabilitation?

    Science.gov (United States)

    ANSWERS by heart Treatments + Tests What Is Cardiac Rehabilitation? A cardiac rehabilitation (rehab) program takes place in a hospital or ... special help in making lifestyle changes. During your rehabilitation program you’ll… • Have a medical evaluation to ...

  18. Diffuse infiltrative cardiac tuberculosis

    International Nuclear Information System (INIS)

    We present the cardiac magnetic resonance images of an unusual form of cardiac tuberculosis. Nodular masses in a sheet-like distribution were seen to infiltrate the outer myocardium and pericardium along most of the cardiac chambers. The lesions showed significant resolution on antitubercular therapy

  19. The output effect of fiscal consolidation plans

    OpenAIRE

    Alesina, Alberto; Favero, Carlo; Giavazzi, Francesco

    2014-01-01

    We show that the correct experiment to evaluate the effects of a fiscal adjustment is the simulation of a multi year fiscal plan rather than of individual fiscal shocks. Simulation of fiscal plans adopted by 16 OECD countries over a 30-year period supports the hypothesis that the effects of consolidations depend on their design. Fiscal adjustments based upon spending cuts are much less costly, in terms of output losses, than tax-based ones and have especially low output costs when they consis...

  20. Unexplained exertional dyspnea caused by low ventricular filling pressures: results from clinical invasive cardiopulmonary exercise testing

    OpenAIRE

    Oldham, William M.; Lewis, Gregory D.; Opotowsky, Alexander R.; Waxman, Aaron B.; Systrom, David M.

    2016-01-01

    To determine whether low ventricular filling pressures are a clinically relevant etiology of unexplained dyspnea on exertion, a database of 619 consecutive, clinically indicated invasive cardiopulmonary exercise tests (iCPETs) was reviewed to identify patients with low maximum aerobic capacity (V̇o2max) due to inadequate peak cardiac output (Qtmax) with normal biventricular ejection fractions and without pulmonary hypertension (impaired: n = 49, V̇o2max = 53% predicted [interquartile range (I...

  1. Output Model of Steel Plant

    Institute of Scientific and Technical Information of China (English)

    ZHANG Long-qiang; TIAN Nai-yuan; ZHANG Jin; XU An-jun

    2008-01-01

    Based on the requirement of compactivity, continuity, and high efficiency, and taking full advantage of cushion capability of flexible parts such as external refining in new generation steel plant, an output model of steel plant was established in terms of matching between BOF and caster. Using this model, the BOF nominal capacity is selected, the caster output and equipment amount are computed, and then the steel plant output is computed.

  2. Nonlinear input-output systems

    Science.gov (United States)

    Hunt, L. R.; Luksic, Mladen; Su, Renjeng

    1987-01-01

    Necessary and sufficient conditions that the nonlinear system dot-x = f(x) + ug(x) and y = h(x) be locally feedback equivalent to the controllable linear system dot-xi = A xi + bv and y = C xi having linear output are found. Only the single input and single output case is considered, however, the results generalize to multi-input and multi-output systems.

  3. Cardiac tumours in children

    Directory of Open Access Journals (Sweden)

    Parsons Jonathan M

    2007-03-01

    Full Text Available Abstract Cardiac tumours are benign or malignant neoplasms arising primarily in the inner lining, muscle layer, or the surrounding pericardium of the heart. They can be primary or metastatic. Primary cardiac tumours are rare in paediatric practice with a prevalence of 0.0017 to 0.28 in autopsy series. In contrast, the incidence of cardiac tumours during foetal life has been reported to be approximately 0.14%. The vast majority of primary cardiac tumours in children are benign, whilst approximately 10% are malignant. Secondary malignant tumours are 10–20 times more prevalent than primary malignant tumours. Rhabdomyoma is the most common cardiac tumour during foetal life and childhood. It accounts for more than 60% of all primary cardiac tumours. The frequency and type of cardiac tumours in adults differ from those in children with 75% being benign and 25% being malignant. Myxomas are the most common primary tumours in adults constituting 40% of benign tumours. Sarcomas make up 75% of malignant cardiac masses. Echocardiography, Computing Tomography (CT and Magnetic Resonance Imaging (MRI of the heart are the main non-invasive diagnostic tools. Cardiac catheterisation is seldom necessary. Tumour biopsy with histological assessment remains the gold standard for confirmation of the diagnosis. Surgical resection of primary cardiac tumours should be considered to relieve symptoms and mechanical obstruction to blood flow. The outcome of surgical resection in symptomatic, non-myxomatous benign cardiac tumours is favourable. Patients with primary cardiac malignancies may benefit from palliative surgery but this approach should not be recommended for patients with metastatic cardiac tumours. Surgery, chemotherapy and radiotherapy may prolong survival. The prognosis for malignant primary cardiac tumours is generally extremely poor.

  4. Chronic vagal stimulation for the treatment of low ejection fraction heart failure : results of the NEural Cardiac TherApy foR Heart Failure (NECTAR-HF) randomized controlled trial

    NARCIS (Netherlands)

    Zannad, Faiez; De Ferrari, Gaetano M; Tuinenburg, Anton E; Wright, David; Brugada, Josep; Butter, Christian; Klein, Helmut; Stolen, Craig; Meyer, Scott; Stein, Kenneth M; Ramuzat, Agnes; Schubert, Bernd; Daum, Doug; Neuzil, Petr; Botman, Cornelis; Castel, Maria Angeles; D'Onofrio, Antonio; Solomon, Scott D; Wold, Nicholas; Ruble, Stephen B

    2015-01-01

    AIM: The neural cardiac therapy for heart failure (NECTAR-HF) was a randomized sham-controlled trial designed to evaluate whether a single dose of vagal nerve stimulation (VNS) would attenuate cardiac remodelling, improve cardiac function and increase exercise capacity in symptomatic heart failure p

  5. On-chip SIDO buck converter with independent outputs

    OpenAIRE

    Martínez García, Herminio; Silva-Martínez, José

    2013-01-01

    The portable electronics market is rapidly migrating towards more compact devices requiring multiple high-integrity high-efficiency voltage supplies for empowering the systems. This paper demonstrates a single inductor used in a buck converter with two output voltages from an input battery with voltage of value 3 V. The main targets are low cross regulation between the two outputs to supply independent load current levels while maintaining desired output voltage values well within the accepta...

  6. Preventing Inductive Output Impedance of High-Frequency Emitter Follower Stages

    OpenAIRE

    Tozer, R. C.; J. Nerad

    1997-01-01

    Large output inductance is one of major issues of high-frequency emitter follower design. The most often suggested technique to reduce its value is the decreasing of AC transconductance which offers small output inductance at the expense of loosing low output resistance. The paper presents a different approach; it is shown that output inductance can be completely cancelled while keeping very low output resistance by introducing a pole at the input node which may be more suitable in many types...

  7. Early goal-directed therapy in moderate to high-risk cardiac surgery patients

    OpenAIRE

    Kapoor Poonam; Kakani Madhava; Chowdhury Ujjwal; Choudhury Minati; Lakshmy R; Kiran Usha

    2008-01-01

    Early goal-directed therapy is a term used to describe the guidance of intravenous fluid and vasopressor/inotropic therapy by using cardiac output or similar parameters in the immediate post-cardiopulmonary bypass in cardiac surgery patients. Early recognition and therapy during this period may result in better outcome. In keeping with this aim in the cardiac surgery patients, we conducted the present study. The study included 30 patients of both sexes, with EuroSCORE ≥3 undergoing coro...

  8. An inquiry into the role of cardiac filling pressure in acclimatization to heat.

    OpenAIRE

    Senay, L. C.

    1986-01-01

    During the first exposure of exercising subjects to hot environments (30-50 degrees C), cardiac output, heart rate, and body temperature increase over that seen in cool environments, while stroke volume decreases. If daily heat exposures occur, during the second heat exposure, heart rates and rectal temperatures are decreased from day 1 while cardiac output is maintained. This decrease in physiological strain occurs with little or no increase in evaporative heat loss. The alleviating agent ap...

  9. Preoperative cardiac risk management

    OpenAIRE

    Vidaković Radosav; Poldermans Don; Nešković Aleksandar N.

    2011-01-01

    Approximately 100 million people undergo noncardiac surgery annually worldwide. It is estimated that around 3% of patients undergoing noncardiac surgery experience a major adverse cardiac event. Although cardiac events, like myocardial infarction, are major cause of perioperative morbidity or mortality, its true incidence is difficult to assess. The risk of perioperative cardiac complications depends mainly on two conditions: 1) identified risk factors, and 2) the type of the surgical p...

  10. Cardiac morbidity risk and depression and anxiety

    DEFF Research Database (Denmark)

    Tully, Phillip J; Pedersen, Susanne S.; Winefield, Helen R;

    2011-01-01

    The aim of this study was to examine depression and anxiety disorders and their characteristic symptoms (anhedonia/low positive affect and anxious arousal, respectively), along with measures of state negative affect (NA) and Type D personality, in relation to cardiac surgery related morbidity...... personality traits were differentially associated with post-cardiac surgery morbidity outcomes independent of cardiac surgery morbidity risk factors. Concurrent investigation of depression and anxiety with respect to cardiac outcomes warrants further research........ Patients awaiting elective coronary artery bypass graft surgery (n=158; 20.9% female; 11.4% concomitant valve surgery; age M=64.7, SD=10.6) underwent the structured MINI International Neuropsychiatric Interview to determine current affective disorders. Patients also completed the Mood and Anxiety Symptom...

  11. Effect of low glomerular filtration rate on evaluating the cardiac function by N-terminal pro-brain natriuretic peptide in patients with hypertension

    International Nuclear Information System (INIS)

    Objective: To assess the diagnostic accuracy of NT-proBNP in hypertension patients by observing the effect of decreased GFR on N-terminal pro-brain natriuretic peptide (NT-proBNP) concentration in patients with different cardiac function. Methods: Eighty-nine hypertension patients were divided into two groups based on the results of UCG. Forty-three patients had normal left ventricular function and 46 patients had dysfunction. GFR, NT-proBNP and other biochemical markers of cardiac and renal function were measured. The factors affecting the NT-proBNP concentration under normal left ventricular function were analyzed, and the diagnostic value of NT-proBNP affected by normal or decreased GFR (> 80 ml/min or ≤80 ml/min) under different left ventricular functions were further assessed. The two-sample t test, rank sum test and multiple regression analysis were used to analyze their statistical difference and relationship. Results: In patients with normal left ventricular function, GFR (β=-0.361, P<0.05) and left ventricular end-diastolic diameter (LVEDD, β=0.385, P<0.05) were significant factors to NT-proBNP level. They were both meaningful compared with LVEF (β=0.189, P>0.05) and septal thickness (β=0.003, P>0.05). The median concentration of NT-proBNP was 13.18 and 24.14 μg/L in patients with normal left ventricular function and dysfunction, respectively (Z=-3.19, P<0.01). While in patients with decreased GFR, 6 cases with normal left ventricular function and 19 cases with dysfunction had a median concentration of NT-proBNP of 38.45 and 44.20 μg/L, respectively (Z=-0.45, P>0.05). In patients with normal GFR, 37 cases with normal left ventricular function and 27 cases with dysfunction had a median concentration of NT-proBNP of 12.51 and 20.31 μg/L, which was lower than that of patients with decreased GFR (Z=-2.76, both P<0.05). The NT-proBNP concentration had no significant difference between patients of normal left ventricular function with decreased GFR and

  12. Output optics for laser velocimeters

    Science.gov (United States)

    Lynch, Dana H. (Inventor); Gunter, William D. (Inventor); Mcalister, Kenneth W. (Inventor)

    1993-01-01

    Space savings are effected in the optical output system of a laser velocimeter. The output system is comprised of pairs of optical fibers having output ends from which a beam of laser light emerges, a transfer lens for each light beam, and at least one final (LV) lens for receiving the light passing through the transfer lenses and for focussing that light at a common crossing point or area. In order to closely couple the transfer lenses to the final lens, each transfer lens is positioned relative to the final lens receiving light therefrom such that the output waist of the corresponding beam received by the final lens from the transfer lens is a virtual waist located before the transfer lens.

  13. Research Output of Australian Universities

    OpenAIRE

    Malcolm Abbot; Hristos Doucouliagos

    2003-01-01

    Research plays an important role in underpinning a country’s economic and social life. Universities are at the centre of the research and human capital generating process. The aim of this paper is to explore the links between research output, research income, academic and non-academic labour and some of the characteristics of Australian universities. The results indicate that research income, academic staff and post-graduates are all positively associated with research output. There are notic...

  14. Uniform Practical Nonlinear Output Regulation

    OpenAIRE

    Marconi, Lorenzo; Praly, Laurent

    2008-01-01

    International audience In this paper, we present a solution to the problem of asymptotic and practical semiglobal regulation by output feedback for nonlinear systems. A key feature of the proposed approach is that practical regulation is achieved uniformly with respect to the dimension of the internal model and to the gain of the stabilizer near the zero error manifold. This property renders the approach interesting for a number of real cases by bridging the gap between output regulation t...

  15. Temperate climate - Innovative outputs nexus

    OpenAIRE

    Coccia, M.

    2014-01-01

    Technological change is a vital human activity that interacts with geographic factors and environment. The purpose of the study here is to analyse the relationship between geo-climate zones of the globe and technological outputs in order to detect favourable areas that spur higher technological change and, as a consequence, human development. The main finding is that innovative outputs are higher in geographical areas with a temperate climate (latitudes). In fact, warm temperate climates are ...

  16. Complementary power output characteristics of electromagnetic generators and triboelectric generators

    International Nuclear Information System (INIS)

    Recently, a triboelectric generator (TEG) has been invented to convert mechanical energy into electricity by a conjunction of triboelectrification and electrostatic induction. Compared to the traditional electromagnetic generator (EMG) that produces a high output current but low voltage, the TEG has different output characteristics of low output current but high output voltage. In this paper, we present a comparative study regarding the fundamentals of TEGs and EMGs. The power output performances of the EMG and the TEG have a special complementary relationship, with the EMG being a voltage source and the TEG a current source. Utilizing a power transformed and managed (PTM) system, the current output of a TEG can reach as high as ∼3 mA, which can be coupled with the output signal of an EMG to enhance the output power. We also demonstrate a design to integrate a TEG and an EMG into a single device for simultaneously harvesting mechanical energy. In addition, the integrated NGs can independently output a high voltage and a high current to meet special needs. (paper)

  17. Complementary power output characteristics of electromagnetic generators and triboelectric generators.

    Science.gov (United States)

    Fan, Feng-Ru; Tang, Wei; Yao, Yan; Luo, Jianjun; Zhang, Chi; Wang, Zhong Lin

    2014-04-01

    Recently, a triboelectric generator (TEG) has been invented to convert mechanical energy into electricity by a conjunction of triboelectrification and electrostatic induction. Compared to the traditional electromagnetic generator (EMG) that produces a high output current but low voltage, the TEG has different output characteristics of low output current but high output voltage. In this paper, we present a comparative study regarding the fundamentals of TEGs and EMGs. The power output performances of the EMG and the TEG have a special complementary relationship, with the EMG being a voltage source and the TEG a current source. Utilizing a power transformed and managed (PTM) system, the current output of a TEG can reach as high as ∼3 mA, which can be coupled with the output signal of an EMG to enhance the output power. We also demonstrate a design to integrate a TEG and an EMG into a single device for simultaneously harvesting mechanical energy. In addition, the integrated NGs can independently output a high voltage and a high current to meet special needs. PMID:24595200

  18. Blunt cardiac rupture.

    Science.gov (United States)

    Martin, T D; Flynn, T C; Rowlands, B J; Ward, R E; Fischer, R P

    1984-04-01

    Blunt injury to the heart ranges from contusion to disruption. This report comprises 14 patients seen during a 6-year period with cardiac rupture secondary to blunt trauma. Eight patients were injured in automobile accidents, two patients were injured in auto-pedestrian accidents, two were kicked in the chest by ungulates, and two sustained falls. Cardiac tamponade was suspected in ten patients. Five patients presented with prehospital cardiac arrest or arrested shortly after arrival. All underwent emergency department thoracotomy without survival. Two patients expired in the operating room during attempted cardiac repair; both had significant extracardiac injury. Seven patients survived, three had right atrial injuries, three had right ventricular injuries, and one had a left atrial injury. Cardiopulmonary bypass was not required for repair of the surviving patients. There were no significant complications from the cardiac repair. The history of significant force dispersed over a relatively small area of the precordium as in a kicking injury from an animal or steering wheel impact should alert the physician to possible cardiac rupture. Cardiac rupture should be considered in patients who present with signs of cardiac tamponade or persistent thoracic bleeding after blunt trauma. PMID:6708151

  19. Biomaterials for cardiac regeneration

    CERN Document Server

    Ruel, Marc

    2015-01-01

    This book offers readers a comprehensive biomaterials-based approach to achieving clinically successful, functionally integrated vasculogenesis and myogenesis in the heart. Coverage is multidisciplinary, including the role of extracellular matrices in cardiac development, whole-heart tissue engineering, imaging the mechanisms and effects of biomaterial-based cardiac regeneration, and autologous bioengineered heart valves. Bringing current knowledge together into a single volume, this book provides a compendium to students and new researchers in the field and constitutes a platform to allow for future developments and collaborative approaches in biomaterials-based regenerative medicine, even beyond cardiac applications. This book also: Provides a valuable overview of the engineering of biomaterials for cardiac regeneration, including coverage of combined biomaterials and stem cells, as well as extracellular matrices Presents readers with multidisciplinary coverage of biomaterials for cardiac repair, including ...

  20. Mathematical cardiac electrophysiology

    CERN Document Server

    Colli Franzone, Piero; Scacchi, Simone

    2014-01-01

    This book covers the main mathematical and numerical models in computational electrocardiology, ranging from microscopic membrane models of cardiac ionic channels to macroscopic bidomain, monodomain, eikonal models and cardiac source representations. These advanced multiscale and nonlinear models describe the cardiac bioelectrical activity from the cell level to the body surface and are employed in both the direct and inverse problems of electrocardiology. The book also covers advanced numerical techniques needed to efficiently carry out large-scale cardiac simulations, including time and space discretizations, decoupling and operator splitting techniques, parallel finite element solvers. These techniques are employed in 3D cardiac simulations illustrating the excitation mechanisms, the anisotropic effects on excitation and repolarization wavefronts, the morphology of electrograms in normal and pathological tissue and some reentry phenomena. The overall aim of the book is to present rigorously the mathematica...

  1. A comparison of sympathoadrenal activity and cardiac performance at rest and during exercise in patients with ventricular demand or atrial synchronous pacing.

    OpenAIRE

    Pehrsson, S K; Hjemdahl, P; Nordlander, R; Aström, H

    1988-01-01

    Cardiac sympathetic function was assessed by measuring the coronary sinus overflow of noradrenaline and dopamine at rest and during supine exercise in eight patients with high degree atrioventricular block treated with dual chamber pacemakers (DDD). Patients exercised (30-60 W) during both ventricular inhibited (VVI) and atrial synchronous (VAT) pacing. During exercise cardiac output increased less markedly in the VVI mode than in the VAT mode. The cardiac output response was entirely stroke ...

  2. Chronic vagal stimulation for the treatment of low ejection fraction heart failure: results of the NEural Cardiac TherApy foR Heart Failure (NECTAR-HF) randomized controlled trial

    OpenAIRE

    Zannad, Faiez; De Ferrari, Gaetano M.; Tuinenburg, Anton E.; Wright, David; Brugada, Josep; Butter, Christian; Klein, Helmut; Stolen, Craig; Meyer, Scott; Stein, Kenneth M.; Ramuzat, Agnes; Schubert, Bernd; Daum, Doug; Neuzil, Petr; Botman, Cornelis

    2014-01-01

    Aim The neural cardiac therapy for heart failure (NECTAR-HF) was a randomized sham-controlled trial designed to evaluate whether a single dose of vagal nerve stimulation (VNS) would attenuate cardiac remodelling, improve cardiac function and increase exercise capacity in symptomatic heart failure patients with severe left ventricular (LV) systolic dysfunction despite guideline recommended medical therapy. Methods: Patients were randomized in a 2 : 1 ratio to receive therapy (VNS ON) or contro...

  3. Low-carbohydrate/high-protein diet improves diastolic cardiac function and the metabolic syndrome in overweight-obese patients with type 2 diabetes

    Directory of Open Access Journals (Sweden)

    H. von Bibra

    2014-03-01

    Conclusions: These data indicate, that a low-glycaemic/high-protein but not a low-fat/high-carbohydrate nutrition modulates diastolic dysfunction in overweight T2D patients, improves insulin resistance and may prevent or delay the onset of diabetic cardiomyopathy and the metabolic syndrome.

  4. Electro-resistive bands for non-invasive cardiac and respiration monitoring, a feasibility study

    International Nuclear Information System (INIS)

    Continuous unobtrusive monitoring of tidal volume, particularly for critical care patients (i.e. neonates and patients in intensive care) during sleep studies and during daily activities, is still an unresolved monitoring need. Also a successful monitoring solution is yet to be proposed for continuous non-invasive cardiac stroke volume monitoring that is a novel clinical need. In this paper we present the feasibility study for a wearable, non-invasive, non-contact and unobtrusive sensor (embedded in a standard T-shirt) based on four electro-resistive bands that simultaneously monitors tidal volume and cardiac stroke volume changes. This low power sensor system (requires only 100 mW and accepts a wide power supply range up to ±18 V); thus the sensor can be easily embedded in existing wearable solutions (i.e. Holter monitors). Moreover, being contactless, it can be worn over bandages or electrodes, and as it does not rely over the integrity of the garment to work, it allows practitioners to perform procedures during monitoring. For this preliminary evaluation, one subject has worn the sensor over the period of 24 h (removing it only to shower); the accuracy of the tidal volume tested against a portable spirometer reported a precision of ±10% also during physical activity; accuracy tests for cardiac output (as it may require invasive procedure) have not been carried out in this preliminary trial. (note)

  5. Low coronary perfusion pressure is associated with endocardial fibrosis in a rat model of volume overload cardiac hypertrophy A redução da pressão de perfusão coronariana está associada com a fibrose endocárdica no modelo de hipertrofia por sobrecarga de volume em ratos

    OpenAIRE

    Maria Carolina Guido; Márcia Kiyomi Koike; Clovis de Carvalho Frimm

    2004-01-01

    Left ventricular hypertrophy following volume overload is regarded as an example of cardiac remodeling without increased fibrosis accumulation. However, infarction is associated with increased fibrosis within the noninfarcted, hypertrophied myocardium, particularly in the subendocardial regions. It is conceivable to suppose that, as also occurs postinfarction, low coronary driving pressure may also interfere with accumulation of myocardial fibrosis following aortocaval fistula. PURPOSE: To in...

  6. The utility of cardiac sonography and capnography in predicting outcome in cardiac arrest

    OpenAIRE

    Nelson, Bret P; Patel, Vaishali R.; Norris, Marlaina M.; Richardson, Barbara K.

    2008-01-01

    Emergency physicians and intensivists are increasingly utilizing capnography and bedside echocardiography during medical resuscitations. These techniques have shown promise in predicting outcomes in cardiac arrest, and no cases of return of spontaneous circulation in the setting of sonographic cardiac standstill and low end-tidal carbon dioxide have been reported. This case report illustrates an example of such an occurrence. Our aims are to report a case of return of spontaneous circulation ...

  7. Extracting cardiac myofiber orientations from high frequency ultrasound images

    Science.gov (United States)

    Qin, Xulei; Cong, Zhibin; Jiang, Rong; Shen, Ming; Wagner, Mary B.; Kirshbom, Paul; Fei, Baowei

    2013-03-01

    Cardiac myofiber plays an important role in stress mechanism during heart beating periods. The orientation of myofibers decides the effects of the stress distribution and the whole heart deformation. It is important to image and quantitatively extract these orientations for understanding the cardiac physiological and pathological mechanism and for diagnosis of chronic diseases. Ultrasound has been wildly used in cardiac diagnosis because of its ability of performing dynamic and noninvasive imaging and because of its low cost. An extraction method is proposed to automatically detect the cardiac myofiber orientations from high frequency ultrasound images. First, heart walls containing myofibers are imaged by B-mode high frequency (hearts.

  8. Cardiac adaptation to endurance exercise in rats.

    Science.gov (United States)

    Fenning, Andrew; Harrison, Glenn; Dwyer, Dan; Rose'Meyer, Roselyn; Brown, Lindsay

    2003-09-01

    Endurance exercise is widely assumed to improve cardiac function in humans. This project has determined cardiac function following endurance exercise for 6 (n = 30) or 12 (n = 25) weeks in male Wistar rats (8 weeks old). The exercise protocol was 30 min/day at 0.8 km/h for 5 days/week with an endurance test on the 6th day by running at 1.2 km/h until exhaustion. Exercise endurance increased by 318% after 6 weeks and 609% after 12 weeks. Heart weight/kg body weight increased by 10.2% after 6 weeks and 24.1% after 12 weeks. Echocardiography after 12 weeks showed increases in left ventricular internal diameter in diastole (6.39 +/- 0.32 to 7.90 +/- 0.17 mm), systolic volume (49 +/- 7 to 83 +/- 11 miccrol) and cardiac output (75 +/- 3 to 107 +/- 8 ml/min) but not left wall thickness in diastole (1.74 +/- 0.07 to 1.80 +/- 0.06 mm). Isolated Langendorff hearts from trained rats displayed decreased left ventricular myocardial stiffness (22 +/- 1.1 to 19.1 +/- 0.3) and reduced purine efflux during pacing-induced workload increases. 31P-NMR spectroscopy in isolated hearts from trained rats showed decreased PCr and PCr/ATP ratios with increased creatine, AMP and ADP concentrations. Thus, this endurance exercise protocol resulted in physiological hypertrophy while maintaining or improving cardiac function. PMID:14575304

  9. Mutations in calmodulin cause ventricular tachycardia and sudden cardiac death

    DEFF Research Database (Denmark)

    Nyegaard, Mette; Overgaard, Michael Toft; Sondergaard, M.T.; Vranas, Marta; Behr, Elijah R.; Hildebrandt, L.L.; Lund, J.; Hedley, Paula L.; Camm, A. John; Wettrell, Göran; Fosdal, Inger; Christiansen, Michael; Borglum, Anders D.

    2012-01-01

    substantial part of sudden cardiac deaths in young individuals. Mutations in RYR2, encoding the cardiac sarcoplasmic calcium channel, have been identified as causative in approximately half of all dominantly inherited CPVT cases. Applying a genome-wide linkage analysis in a large Swedish family with a severe......Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a devastating inherited disorder characterized by episodic syncope and/or sudden cardiac arrest during exercise or acute emotion in individuals without structural cardiac abnormalities. Although rare, CPVT is suspected to cause a...... calmodulin-binding-domain peptide at low calcium concentrations. We conclude that calmodulin mutations can cause severe cardiac arrhythmia and that the calmodulin genes are candidates for genetic screening of individual cases and families with idiopathic ventricular tachycardia and unexplained sudden cardiac...

  10. [Cardiac evaluation before non-cardiac surgery].

    Science.gov (United States)

    Menzenbach, Jan; Boehm, Olaf

    2016-07-01

    Before non-cardiac surgery, evaluation of cardiac function is no frequent part of surgical treatment. European societies of anesthesiology and cardiology published consensus-guidelines in 2014 to present a reasonable approach for preoperative evaluation. This paper intends to differentiate the composite of perioperative risk and to display the guidelines methodical approach to handle it. Features to identify patients at risk from an ageing population with comorbidities, are the classification of surgical risk, functional capacity and risk indices. Application of diagnostic means, should be used adjusted to this risk estimation. Cardiac biomarkers are useful to discover risk of complications or mortality, that cannot be assessed by clinical signs. After preoperative optimization and perioperative cardiac protection, the observation of the postoperative period remains, to prohibit complications or even death. In consideration of limited resources of intensive care department, postoperative ward rounds beyond intensive care units are considered to be an appropriate instrument to avoid or recognize complications early to reduce postoperative mortality. PMID:27479258

  11. Computing Dynamic Output Feedback Laws

    OpenAIRE

    Verschelde, Jan; Wang, Yusong

    2003-01-01

    The pole placement problem asks to find laws to feed the output of a plant governed by a linear system of differential equations back to the input of the plant so that the resulting closed-loop system has a desired set of eigenvalues. Converting this problem into a question of enumerative geometry, efficient numerical homotopy algorithms to solve this problem for general Multi-Input-Multi-Output (MIMO) systems have been proposed recently. While dynamic feedback laws offer a wider range of use...

  12. Cardiac metabolism and arrhythmias

    OpenAIRE

    Barth, Andreas S.; Tomaselli, Gordon F.

    2009-01-01

    Sudden cardiac death remains a leading cause of mortality in the Western world, accounting for up to 20% of all deaths in the U.S.1, 2 The major causes of sudden cardiac death in adults age 35 and older are coronary artery disease (70–80%) and dilated cardiomyopathy (10–15%).3 At the molecular level, a wide variety of mechanisms contribute to arrhythmias that cause sudden cardiac death, ranging from genetic predisposition (rare mutations and common polymorphisms in ion channels and structural...

  13. [Cardiac Rehabilitation 2015].

    Science.gov (United States)

    Hoffmann, Andreas

    2015-11-25

    The goals of cardiac rehabilitation are (re-)conditioning and secondary prevention in patients with heart disease or an elevated cardiovascular risk profile. Rehabilitation is based on motivation through education, on adapted physical activity, instruction of relaxation techniques, psychological support and optimized medication. It is performed preferably in groups either in outpatient or inpatient settings. The Swiss working group on cardiac rehabilitation provides a network of institutions with regular quality auditing. Positive effects of rehabilitation programs on mortality and morbidity have been established by numerous studies. Although a majority of patients after cardiac surgery are being referred to rehabilitation, these services are notoriously underused after catheter procedures. PMID:26602848

  14. Comprehensive cardiac rehabilitation

    DEFF Research Database (Denmark)

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

    2006-01-01

    OBJECTIVES: The costs of comprehensive cardiac rehabilitation are established and compared to the corresponding costs of usual care. The effect on health-related quality of life is analyzed. METHODS: An unprecedented and very detailed cost assessment was carried out, as no guidelines existed for...... uncertain and may be as high as euro 1.877. CONCLUSIONS: Comprehensive cardiac rehabilitation is more costly than usual care, and the higher costs are not outweighed by a quality of life gain. Comprehensive cardiac rehabilitation is, therefore, not cost-effective....

  15. Reoperation for bleeding in cardiac surgery

    DEFF Research Database (Denmark)

    Kristensen, Katrine Lawaetz; Rauer, Line Juul; Mortensen, Poul Erik; Kjeldsen, Bo Juel

    2012-01-01

    At Odense University Hospital (OUH), 5-9% of all unselected cardiac surgical patients undergo reoperation due to excessive bleeding. The reoperated patients have an approximately three times greater mortality than non-reoperated. To reduce the rate of reoperations and mortality due to postoperative...... bleeding, we aim to identify risk factors that predict reoperation. A total of 1452 consecutive patients undergoing cardiac surgery using extracorporeal circulation (ECC) between November 2005 and December 2008 at OUH were analysed. Statistical tests were used to identify risk factors for reoperation. We...... after cardiac surgery was low ejection fraction, high EuroSCORE, procedures other than isolated CABG, elongated time on ECC, low body mass index, diabetes mellitus and preoperatively elevated s-creatinine. Reoperated patients significantly had a greater increase in postoperative s-creatinine and higher...

  16. Molecular Basis of Cardiac Myxomas

    Directory of Open Access Journals (Sweden)

    Pooja Singhal

    2014-01-01

    Full Text Available Cardiac tumors are rare, and of these, primary cardiac tumors are even rarer. Metastatic cardiac tumors are about 100 times more common than the primary tumors. About 90% of primary cardiac tumors are benign, and of these the most common are cardiac myxomas. Approximately 12% of primary cardiac tumors are completely asymptomatic while others present with one or more signs and symptoms of the classical triad of hemodynamic changes due to intracardiac obstruction, embolism and nonspecific constitutional symptoms. Echocardiography is highly sensitive and specific in detecting cardiac tumors. Other helpful investigations are chest X-rays, magnetic resonance imaging and computerized tomography scan. Surgical excision is the treatment of choice for primary cardiac tumors and is usually associated with a good prognosis. This review article will focus on the general features of benign cardiac tumors with an emphasis on cardiac myxomas and their molecular basis.

  17. Effect of cardiac function on aortic peak time and peak enhancement during coronary CT angiography

    Energy Technology Data Exchange (ETDEWEB)

    Sakai, Shuji, E-mail: sakai@shs.kyushu-u.ac.j [Department of Health Sciences, Graduate School of Medical Sciences, Kyushu University, 3-1-1, Maidashi, Higashi-ku, Fukuoka 812-8582 (Japan); Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, 3-1-1, Maidashi, Higashi-ku, Fukuoka 812-8582 (Japan); Yabuuchi, Hidetake, E-mail: yabuuchi@radiol.med.kyushu-u.ac.j [Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, 3-1-1, Maidashi, Higashi-ku, Fukuoka 812-8582 (Japan); Chishaki, Akiko, E-mail: chishaki@shs.kyushu-u.ac.j [Department of Health Sciences, Graduate School of Medical Sciences, Kyushu University, 3-1-1, Maidashi, Higashi-ku, Fukuoka 812-8582 (Japan); Department of Cardiovascular Medicine, Graduate School of Medical Sciences, Kyushu University, 3-1-1, Maidashi, Higashi-ku, Fukuoka 812-8582 (Japan); Okafuji, Takashi, E-mail: oka-pu@radiol.med.kyushu-u.ac.j [Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, 3-1-1, Maidashi, Higashi-ku, Fukuoka 812-8582 (Japan); Matsuo, Yoshio, E-mail: yymatsuo@radiol.med.kyushu-u.ac.j [Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, 3-1-1, Maidashi, Higashi-ku, Fukuoka 812-8582 (Japan); Kamitani, Takeshi, E-mail: kamitani@radiol.med.kyushu-u.ac.j [Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, 3-1-1, Maidashi, Higashi-ku, Fukuoka 812-8582 (Japan); Setoguchi, Taro, E-mail: taro-s@radiol.med.kyushu-u.ac.j [Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, 3-1-1, Maidashi, Higashi-ku, Fukuoka 812-8582 (Japan); Honda, Hiroshi, E-mail: honda@radiol.med.kyushu-u.ac.j [Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, 3-1-1, Maidashi, Higashi-ku, Fukuoka 812-8582 (Japan)

    2010-08-15

    Purpose: To examine the manner in which cardiac function affects the magnitude and timing of aortic contrast enhancement during coronary CT angiography (CTA). Materials and methods: Twenty-nine patients (21 men, 8 women; mean age, 64.4 {+-} 13.4 years; mean weight, 59.4 {+-} 10.3 kg) underwent measurement of cardiac output within 2 weeks of coronary CTA. The cardiac output of each patient was measured by the thermodilution technique and the cardiac index was calculated from the body surface area. During coronary CTA, attenuation of the descending aorta was measured at the workstation every 3 s. The aortic peak time (APT) and aortic peak enhancement (APE) of each patient were calculated. Pearson's correlation coefficient analysis was used to investigate the relationships between the cardiac output or cardiac index and APT or APE. Furthermore, the relationship between patient factors or parameters on test bolus injection and APT or APE was also evaluated. Results: The range of cardiac output, cardiac index, APT, and APE was 1.55-10.46 L/min (mean: 4.77 {+-} 2.13), 1.11-5.30 L/(min-m{sup 2}) (mean: 3.28 {+-} 1.08), 25-51 s (mean: 38.3 {+-} 7.5), and 273.1-598.1 HU (mean: 390.4 {+-} 72.1), respectively. With an increase in the cardiac index, both APT (r = -0.698, p < 0.0001) and APE (r = -0.573, p = 0.0009) decreased. There were significant correlations between the patient body weight and APT and APE with the test bolus injection, and with APT and APE during coronary CTA. Conclusion: The APT and APE during coronary CTA are closely related to cardiac function.

  18. World Input-Output Network.

    Directory of Open Access Journals (Sweden)

    Federica Cerina

    Full Text Available Production systems, traditionally analyzed as almost independent national systems, are increasingly connected on a global scale. Only recently becoming available, the World Input-Output Database (WIOD is one of the first efforts to construct the global multi-regional input-output (GMRIO tables. By viewing the world input-output system as an interdependent network where the nodes are the individual industries in different economies and the edges are the monetary goods flows between industries, we analyze respectively the global, regional, and local network properties of the so-called world input-output network (WION and document its evolution over time. At global level, we find that the industries are highly but asymmetrically connected, which implies that micro shocks can lead to macro fluctuations. At regional level, we find that the world production is still operated nationally or at most regionally as the communities detected are either individual economies or geographically well defined regions. Finally, at local level, for each industry we compare the network-based measures with the traditional methods of backward linkages. We find that the network-based measures such as PageRank centrality and community coreness measure can give valuable insights into identifying the key industries.

  19. World Input-Output Network.

    Science.gov (United States)

    Cerina, Federica; Zhu, Zhen; Chessa, Alessandro; Riccaboni, Massimo

    2015-01-01

    Production systems, traditionally analyzed as almost independent national systems, are increasingly connected on a global scale. Only recently becoming available, the World Input-Output Database (WIOD) is one of the first efforts to construct the global multi-regional input-output (GMRIO) tables. By viewing the world input-output system as an interdependent network where the nodes are the individual industries in different economies and the edges are the monetary goods flows between industries, we analyze respectively the global, regional, and local network properties of the so-called world input-output network (WION) and document its evolution over time. At global level, we find that the industries are highly but asymmetrically connected, which implies that micro shocks can lead to macro fluctuations. At regional level, we find that the world production is still operated nationally or at most regionally as the communities detected are either individual economies or geographically well defined regions. Finally, at local level, for each industry we compare the network-based measures with the traditional methods of backward linkages. We find that the network-based measures such as PageRank centrality and community coreness measure can give valuable insights into identifying the key industries. PMID:26222389

  20. Input/output interface module

    Science.gov (United States)

    Ozyazici, E. M.

    1980-01-01

    Module detects level changes in any of its 16 inputs, transfers changes to its outputs, and generates interrupts when changes are detected. Up to four changes-in-state per line are stored for later retrieval by controlling computer. Using standard TTL logic, module fits 19-inch rack-mounted console.

  1. Remote input/output station

    CERN Multimedia

    1972-01-01

    A general view of the remote input/output station installed in building 112 (ISR) and used for submitting jobs to the CDC 6500 and 6600. The card reader on the left and the line printer on the right are operated by programmers on a self-service basis.

  2. Coral Mortality and Bleaching Output

    Science.gov (United States)

    COMBO is a spreadsheet-based model for the use of managers, conservationists, and biologists for projecting the effects of climate change on coral reefs at local-to-regional scales. The COMBO (Coral Mortality and Bleaching Output) model calculates the impacts to coral reefs from...

  3. Judicial Influence on Policy Outputs?

    DEFF Research Database (Denmark)

    Martinsen, Dorte Sindbjerg

    2015-01-01

    ) social policy outputs. A taxonomy of judicial influence is constructed, and expectations of institutional and political conditions on judicial influence are presented. The analysis draws on an extensive novel data set and examines judicial influence on EU social policies over time, that is, between 1958...... political responses to attenuate unwelcome jurisprudence and constrain the legislative effect of judicial decisions....

  4. Temperate climate - Innovative outputs nexus

    NARCIS (Netherlands)

    Coccia, M.

    2014-01-01

    Technological change is a vital human activity that interacts with geographic factors and environment. The purpose of the study here is to analyse the relationship between geo-climate zones of the globe and technological outputs in order to detect favourable areas that spur higher technological chan

  5. Automatic Implantable Cardiac Defibrillator

    Medline Plus

    Full Text Available Automatic Implantable Cardiac Defibrillator February 19, 2009 Halifax Health Medical Center, Daytona Beach, FL Welcome to Halifax Health Daytona Beach, Florida. Over the next hour you' ...

  6. Sudden Cardiac Arrest

    Science.gov (United States)

    ... scan, or MUGA, which shows how well your heart is pumping blood. Magnetic resonance imaging (MRI) which gives doctors detailed pictures of your heart. How is SCA treated? Sudden cardiac arrest should ...

  7. Sudden Cardiac Arrest

    Science.gov (United States)

    ... Heart Risk Factors & Prevention Heart Diseases & Disorders Atrial Fibrillation (AFib) Sudden Cardiac Arrest (SCA) SCA: Who's At Risk? Prevention of SCA What Causes SCA? SCA Awareness Atrial Flutter Heart Block Heart Failure Sick Sinus Syndrome Substances & Heart Rhythm Disorders Symptoms & ...

  8. Sudden cardiac death

    Directory of Open Access Journals (Sweden)

    Aranđelović Aleksandra Č.

    2004-01-01

    Full Text Available Sudden cardiac death in an athlete is rare and tragic event. An athlete's death draws high public attention given that athletes are considered the healthiest category of society. The vast majority of sudden cardiac death in young athletes is due to congenital cardiac malformations such as hypertrophie cardiomyopathy and various coronary artery anomalies. In athletes over age 35, the usual cause of sudden cardiac death is coronary artery disease. With each tragic death of a young athlete, there is a question why this tragedy has not been prevented. The American College of Sports Medicine and the American Heart Association recommend that a pre-participation exam should include a complete cardiovascular history and physical examination.

  9. Cardiac Risk Assessment

    Science.gov (United States)

    ... to assess cardiac risk include: High-sensitivity C-reactive protein (hs-CRP) : Studies have shown that measuring ... LDL-C but does not respond to typical strategies to lower LDL-C such as diet, exercise, ...

  10. Cardiac arrest - cardiopulmonary resuscitation

    Institute of Scientific and Technical Information of China (English)

    Basri Lenjani; Besnik Elshani; Nehat Baftiu; Kelmend Pallaska; Kadir Hyseni; Njazi Gashi; Nexhbedin Karemani; Ilaz Bunjaku; Taxhidin Zaimi; Arianit Jakupi

    2014-01-01

    Objective:To investigate application of cardiopulmonary resuscitation(CPR) measures within the golden minutes inEurope.Methods:The material was taken from theUniversityClinical Center ofKosovo -EmergencyCentre inPristina, during the two(2) year period(2010-2011).The collected date belong to the patients with cardiac arrest have been recorded in the patients' log book protocol at the emergency clinic.Results:During the2010 to2011 in the emergency center of theCUCK inPristina have been treated a total of269 patients with cardiac arrest, of whom159 or59.1% have been treated in2010, and110 patients or40.9% in2011.Of the269 patients treated in the emergency centre,93 or34.6% have exited lethally in the emergency centre, and176 or 65.4% have been transferred to other clinics.In the total number of patients with cardiac arrest, males have dominated with186 cases, or69.1%.The average age of patients included in the survey was56.7 year oldSD±16.0 years.Of the269 patients with cardiac arrest, defibrillation has been applied for93 or34.6% of patients.In the outpatient settings defibrillation has been applied for3 or3.2% of patients.Patients were defibrillated with application of one to four shocks. Of27 cases with who have survived cardiac arrest, none of them have suffered cardiac arrest at home,3 or11.1% of them have suffered cardiac arrest on the street, and24 or88.9% of them have suffered cardiac arrest in the hospital.5 out of27 patients survived have ended with neurological impairment.Cardiac arrest cases were present during all days of the week, but frequently most reported cases have been onMonday with32.0% of cases, and onFriday with24.5% of cases. Conclusions:All survivors from cardiac arrest have received appropriate medical assistance within10 min from attack, which implies that if cardiac arrest occurs near an institution health care(with an opportunity to provide the emergent health care) the rate of survival is higher.

  11. Awareness in cardiac anesthesia.

    LENUS (Irish Health Repository)

    Serfontein, Leon

    2010-02-01

    Cardiac surgery represents a sub-group of patients at significantly increased risk of intraoperative awareness. Relatively few recent publications have targeted the topic of awareness in this group. The aim of this review is to identify areas of awareness research that may equally be extrapolated to cardiac anesthesia in the attempt to increase understanding of the nature and significance of this scenario and how to reduce it.

  12. Safety in cardiac surgery

    OpenAIRE

    Siregar, S.

    2013-01-01

    The monitoring of safety in cardiac surgery is a complex process, which involves many clinical, practical, methodological and statistical issues. The objective of this thesis was to measure and to compare safety in cardiac surgery in The Netherlands using the Netherlands Association for Cardio-Thoracic Surgery (NVT) database. The safety of care is usually measured using patient outcomes. If outcomes are not available, the process and structure of care may be used. Outcomes should be adjusted ...

  13. Cardiac rehabilitation in Germany.

    Science.gov (United States)

    Karoff, Marthin; Held, Klaus; Bjarnason-Wehrens, Birna

    2007-02-01

    The purpose of this review is to give an overview of the rehabilitation measures provided for cardiac patients in Germany and to outline its legal basis and outcomes. In Germany the cardiac rehabilitation system is different from rehabilitation measures in other European countries. Cardiac rehabilitation in Germany since 1885 is based on specific laws and the regulations of insurance providers. Cardiac rehabilitation has predominantly been offered as an inpatient service, but has recently been complemented by outpatient services. A general agreement on the different indications for offering these two services has yet to be reached. Cardiac rehabilitation is mainly offered after an acute cardiac event and bypass surgery. It is also indicated in severe heart failure and special cases of percutaneous coronary intervention. Most patients are men (>65%) and the age at which events occur is increasing. The benefits obtained during the 3-4 weeks after an acute event, and confirmed in numerous studies, are often later lost under 'usual care' conditions. Many attempts have been made by rehabilitation institutions to improve this deficit by providing intensive aftercare. One instrument set up to achieve this is the nationwide institution currently comprising more than 6000 heart groups with approximately 120000 outpatients. After coronary artery bypass grafting or acute coronary syndrome cardiac rehabilitation can usually be started within 10 days. The multidisciplinary rehabilitation team consists of cardiologists, psychologists, exercise therapists, social workers, nutritionists and nurses. The positive effects of cardiac rehabilitation are also important economically, for example, for the improvement of secondary prevention and vocational integration. PMID:17301623

  14. Ranolazine in Cardiac Arrhythmia.

    Science.gov (United States)

    Saad, Marwan; Mahmoud, Ahmed; Elgendy, Islam Y; Richard Conti, C

    2016-03-01

    Ranolazine utilization in the management of refractory angina has been established by multiple randomized clinical studies. However, there is growing evidence showing an evolving role in the field of cardiac arrhythmias. Multiple experimental and clinical studies have evaluated the role of ranolazine in prevention and management of atrial fibrillation, with ongoing studies on its role in ventricular arrhythmias. In this review, we will discuss the pharmacological, experimental, and clinical evidence behind ranolazine use in the management of various cardiac arrhythmias. PMID:26459200

  15. Cardiac tumours in infancy

    OpenAIRE

    Yadava, O.P.

    2012-01-01

    Cardiac tumours in infancy are rare and are mostly benign with rhabdomyomas, fibromas and teratomas accounting for the majority. The presentation depends on size and location of the mass as they tend to cause cavity obstruction or arrhythmias. Most rhabdomyomas tend to regress spontaneously but fibromas and teratomas generally require surgical intervention for severe haemodynamic or arrhythmic complications. Other relatively rare cardiac tumours too are discussed along with an Indian perspect...

  16. Solar Power Station Output Inverter Control Design

    Directory of Open Access Journals (Sweden)

    J. Bauer

    2011-04-01

    Full Text Available The photovoltaic applications spreads in these days fast, therefore they also undergo great development. Because the amount of the energy obtained from the panel depends on the surrounding conditions, as intensity of the sun exposure or the temperature of the solar array, the converter must be connected to the panel output. The Solar system equipped with inverter can supply small loads like notebooks, mobile chargers etc. in the places where the supplying network is not present. Or the system can be used as a generator and it shall deliver energy to the supply network. Each type of the application has different requirements on the converter and its control algorithm. But for all of them the one thing is common – the maximal efficiency. The paper focuses on design and simulation of the low power inverter that acts as output part of the whole converter. In the paper the design of the control algorithm of the inverter for both types of inverter application – for islanding mode and for operation on the supply grid – is discussed. Attention is also paid to the design of the output filter that should reduce negative side effects of the converter on the supply network.

  17. Monitoring radiation use in cardiac fluoroscopy imaging procedures

    International Nuclear Information System (INIS)

    Purpose: Timely identification of systematic changes in radiation delivery of an imaging system can lead to a reduction in risk for the patients involved. However, existing quality assurance programs involving the routine testing of equipment performance using phantoms are limited in their ability to effectively carry out this task. To address this issue, the authors propose the implementation of an ongoing monitoring process that utilizes procedural data to identify unexpected large or small radiation exposures for individual patients, as well as to detect persistent changes in the radiation output of imaging platforms. Methods: Data used in this study were obtained from records routinely collected during procedures performed in the cardiac catheterization imaging facility at St. Andrew's War Memorial Hospital, Brisbane, Australia, over the period January 2008-March 2010. A two stage monitoring process employing individual and exponentially weighted moving average (EWMA) control charts was developed and used to identify unexpectedly high or low radiation exposure levels for individual patients, as well as detect persistent changes in the radiation output delivered by the imaging systems. To increase sensitivity of the charts, we account for variation in dose area product (DAP) values due to other measured factors (patient weight, fluoroscopy time, and digital acquisition frame count) using multiple linear regression. Control charts are then constructed using the residual values from this linear regression. The proposed monitoring process was evaluated using simulation to model the performance of the process under known conditions. Results: Retrospective application of this technique to actual clinical data identified a number of cases in which the DAP result could be considered unexpected. Most of these, upon review, were attributed to data entry errors. The charts monitoring the overall system radiation output trends demonstrated changes in equipment performance

  18. Monitoring radiation use in cardiac fluoroscopy imaging procedures

    Energy Technology Data Exchange (ETDEWEB)

    Stevens, Nathaniel T.; Steiner, Stefan H.; Smith, Ian R.; MacKay, R. Jock [Department of Statistics and Actuarial Sciences, Business and Industrial Statistics Research Group, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada); St. Andrew' s Medical Institute, St. Andrew' s War Memorial Hospital, Brisbane, Queensland 4000 (Australia); Department of Statistics and Actuarial Sciences, Business and Industrial Statistics Research Group, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada)

    2011-01-15

    Purpose: Timely identification of systematic changes in radiation delivery of an imaging system can lead to a reduction in risk for the patients involved. However, existing quality assurance programs involving the routine testing of equipment performance using phantoms are limited in their ability to effectively carry out this task. To address this issue, the authors propose the implementation of an ongoing monitoring process that utilizes procedural data to identify unexpected large or small radiation exposures for individual patients, as well as to detect persistent changes in the radiation output of imaging platforms. Methods: Data used in this study were obtained from records routinely collected during procedures performed in the cardiac catheterization imaging facility at St. Andrew's War Memorial Hospital, Brisbane, Australia, over the period January 2008-March 2010. A two stage monitoring process employing individual and exponentially weighted moving average (EWMA) control charts was developed and used to identify unexpectedly high or low radiation exposure levels for individual patients, as well as detect persistent changes in the radiation output delivered by the imaging systems. To increase sensitivity of the charts, we account for variation in dose area product (DAP) values due to other measured factors (patient weight, fluoroscopy time, and digital acquisition frame count) using multiple linear regression. Control charts are then constructed using the residual values from this linear regression. The proposed monitoring process was evaluated using simulation to model the performance of the process under known conditions. Results: Retrospective application of this technique to actual clinical data identified a number of cases in which the DAP result could be considered unexpected. Most of these, upon review, were attributed to data entry errors. The charts monitoring the overall system radiation output trends demonstrated changes in equipment

  19. State-shared model for multiple-input multiple-output systems

    Institute of Scientific and Technical Information of China (English)

    Zhenhua TIAN; Karlene A. HOO

    2005-01-01

    This work proposes a method to construct a state-shared model for multiple-input multiple-output (MIMO)systems. A state-shared model is defined as a linear time invariant state-space structure that is driven by measurement signals-the plant outputs and the manipulated variables, but shared by different multiple input/output models. The genesis of the state-shared model is based on a particular reduced non-minimal realization. Any such realization necessarily fulfills the requirement that the output of the state-shared model is an asymptotically correct estimate of the output of the plant, if the process model is selected appropriately. The approach is demonstrated on a nonlinear MIMO system- a physiological model of calcium fluxes that controls muscle contraction and relaxation in human cardiac myocytes.

  20. Cardiac Image Registration

    Directory of Open Access Journals (Sweden)

    2008-09-01

    Full Text Available Long procedure time and somewhat suboptimal results hinder the widespread use of catheter ablation of complex arrhythmias such as atrial fibrillation (AF. Due to lack of contrast differentiation between the area of interest and surrounding structures in a moving organ like heart, there is a lack of proper intraprocedural guidance using current imaging techniques for ablation. Cardiac image registration is currently under investigation and is in clinical use for AF ablation. Cardiac image registration, which involves integration of two images in the context of left atrium (LA, is intermodal, with the acquired image and the real-time reference image residing in different image spaces, and involves optimization, where one image space is transformed into the other. Unlike rigid body registration, cardiac image registration is unique and challenging due to cardiac motion during the cardiac cycle and due to respiration. This review addresses the basic principles of the emerging technique of registration and the inherent limitations as they relate to cardiac imaging and registration.

  1. Cardiac Image Registration

    Directory of Open Access Journals (Sweden)

    Jasbir Sra

    2008-09-01

    Full Text Available Long procedure time and somewhat suboptimal results hinder the widespread use of catheter ablation of complex arrhythmias such as atrial fibrillation (AF. Due to lack of contrast differentiation between the area of interest and surrounding structures in a moving organ like heart, there is a lack of proper intraprocedural guidance using current imaging techniques for ablation. Cardiac image registration is currently under investigation and is in clinical use for AF ablation. Cardiac image registration, which involves integration of two images in the context of the left atrium (LA, is intermodal, with the acquired image and the real-time reference image residing in different image spaces, and involves optimization, where one image space is transformed into the other. Unlike rigid body registration, cardiac image registration is unique and challenging due to cardiac motion during the cardiac cycle and due to respiration. This review addresses the basic principles of the emerging technique of registration and the inherent limitations as they relate to cardiac imaging and registration.

  2. Holographic velocimetry for evaluation of cardiac valves

    International Nuclear Information System (INIS)

    Holographic velocimetry is a noninvasive method for fluid flow analysis, making it possible to determine flow field characteristics for any instant in a flow cycle. The use of holographic velocimetry to assess prosthetic heart valve performance has never before been accomplished. However, it seems readily apparent that much pertinent information will be gained from it, such as the exact location and quantitative analysis of stagnation zones, high shear and high velocity regions. A comparison of the results from holographic velocimetry are made with those of laser Doppler anemometry. The first study deals with steady state flow analysis at peak systolic flow rates for normal cardiac outputs

  3. Low-level ionizing radiation from noninvasive cardiac imaging: can we extrapolate estimated risks from epidemiologic data to the clinical setting?

    Science.gov (United States)

    Laskey, Warren K; Feinendegen, Ludwig E; Neumann, Ronald D; Dilsizian, Vasken

    2010-05-01

    Clinical decision-making regarding the use of low-level ionizing radiation for diagnostic and/or therapeutic purposes in patients with cardiovascular disease must, as in all other clinical scenarios, encompass the broad range of the risk-benefit ratio. Concerns regarding the late carcinogenic effects of exposure to low levels, i.e., atomic bomb explosions. However, ongoing debate regarding the true incremental risk to subjects exposed to doses currently administered in cardiovascular procedures fails to take into account the uncertainty of the dose-response relationship in this lower range, as well as tissue-specific reparative responses, also manifest at lower levels of exposure. The present discussion draws attention to both of these aspects as they relate to clinical decision-making. PMID:20466348

  4. Postoperative cardiac arrest due to cardiac surgery complications

    International Nuclear Information System (INIS)

    To examine the role of anesthetists in the management of cardiac arrest occurring in association with cardiac anesthesia. In this retrospective study we studied the potential performances for each of the relevant incidents among 712 patients undergoing cardiac operations at Golestan and Naft Hospitals Ahwaz between November 2006 and July 2008. Out of total 712 patients undergoing cardiac surgery, cardiac arrest occurred in 28 cases (3.9%) due to different postoperative complications. This included massive bleeding (50% of cardiac arrest cases, 1.9% of patients); pulseless supra ventricular tachycardia (28.5% of cardiac arrest cases, 1.1% of patients); Heart Failure (7% of cardiac arrest cases, 0.2% of patients); Aorta Arc Rapture (3.5% of cardiac arrest cases, 0.1% of patients); Tamponade due to pericardial effusion (3.5% of cardiac arrest cases, 0.1% of total patients); Right Atrium Rupture (3.5% of cardiac arrest cases, 0.1% of patients) were detected after cardiac surgery. Out of 28 cases 7 deaths occurred (25% of cardiac arrest cases, 0.1% of patients). The most prevalent reason for cardiac arrest during post operative phase was massive bleeding (50%) followed by pulseless supra ventricular tachycardia (28.5%). Six patients had some morbidity and the remaining 15 patients recovered. There are often multiple contributing factors to a cardiac arrest under cardiac anesthesia, as much a complete systematic assessment of the patient, equipment, and drugs should be completed. We also found that the diagnosis and management of cardiac arrest in association with cardiac anesthesia differs considerably from that encountered elsewhere. (author)

  5. Assessing and improving teamwork in cardiac surgery

    NARCIS (Netherlands)

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

    2010-01-01

    Obiective Paediatric cardiac surgery {PCS) has a low enor tolerance, is dependent upon sophisticated organisational structures and demands high levels of cognitive and technical performance. The aim of the study was to assess the role of intraoperat¡ve non-routine events (NBEs) and team performance

  6. Exosomes in cardiac injury and repair

    NARCIS (Netherlands)

    Vrijsen, K.R.

    2013-01-01

    Stem cell therapy has been proposed as a strategy to regenerate the damaged myocardium after myocardial infarction. The differentiation capacity of many different stem cells to cardiomyocytes and blood vessels and their effect on cardiac function has been studied. Despite low retention and engraftme

  7. UFO - The Universal FEYNRULES Output

    Science.gov (United States)

    Degrande, Céline; Duhr, Claude; Fuks, Benjamin; Grellscheid, David; Mattelaer, Olivier; Reiter, Thomas

    2012-06-01

    We present a new model format for automatized matrix-element generators, the so-called Universal FEYNRULES Output (UFO). The format is universal in the sense that it features compatibility with more than one single generator and is designed to be flexible, modular and agnostic of any assumption such as the number of particles or the color and Lorentz structures appearing in the interaction vertices. Unlike other model formats where text files need to be parsed, the information on the model is encoded into a PYTHON module that can easily be linked to other computer codes. We then describe an interface for the MATHEMATICA package FEYNRULES that allows for an automatic output of models in the UFO format.

  8. Telecommunications dynamics, output and employment

    OpenAIRE

    Jungmittag, Andre; Welfens, Paul J.J.

    2006-01-01

    In EU countries, opening up of telecommunications markets and regulations have helped to reduce the price of digital services which is an important quasi-input factor in all firms. Integrating the use of telecommunications in a macroeconomic production function is the analytical starting point for our interdependent analysis of output, use of telecommunications and employment. Based on unit root and co-integration analysis as well as an error correction three-equation model which are estimate...

  9. Improving nuclear power station output

    International Nuclear Information System (INIS)

    The total annual output of Nuclear Electric's five advanced gas cooled reactor (AGR) stations has increased by more than 80% from 21.7 to 39.3 TW·h over the last four years since the company was formed. This has been achieved through increasing both the capability (maximum power output) and the availability of the reactors. The successive stages of technical modifications, testing and safety case preparation and approval by which the capability of each of the reactor units was raised, whilst ensuring safety, are detailed and the further stages that are planned for the future are outlined. The availability of the reactors has been increased by removing the constraints associated with refuelling operations, reducing statutory overhaul lengths and frequency, and reducing unplanned losses. In 1990, the fuel routes at four of the five stations operated too slowly to supply the fuel needed by the reactors and also required substantial periods of outage of the fuel route for modifications in order to consolidate their off-load refuelling safety cases. The programmes of work undertaken are outlined and the improved performance of the fuel route operations to match the increased output of reactor units is detailed. The future developments, particularly of on-load refuelling, are outlined. The lengths of statutory outages have been reduced by improved management and performance of plant operations and maintenance, and permission has also been received to extend the period between overhauls from 24 to 36 months. Unplanned losses have also been reduced. The improvements in output have not been achieved at the expense of safety nor by increasing the resources deployed. Indeed the reverse is true; key safety indicators show an improvement in both nuclear and industrial safety; and the manpower employed at the AGRs and the total annual expenditure in real terms have both decreased over the past four years. (author). 7 figs, 1 tab

  10. Low-dose dobutamine stress test for the evaluation of cardiac function using ECG-gated SPECT scintigraphy with 99mTc-MIBI

    International Nuclear Information System (INIS)

    Although 201TlCl myocardial scintigraphy has so far been widely used for the evaluation of the viability of the myocardial infarcted area, functional evaluation using low dose dobutamine (DOB) loaded echography also became recently available. We performed 99mTc-MIBI gated SPECT on eight cases of myocardial infarction at rest and low dose (4-6μg/kg/min) DOB-loading and related data were collected. Next, we calculated myocardial count increase rate (%WT=ES-ED/ED x 100) with left ventricular contraction from end-diastolic (ED) and end-systolic (ES) pictures in short-axial image, and made a comparative examination of regional contractilities at rest and DOB-loading. DOB-loaded echography performed on the same cases at the same dose revealed 15 segments as infarcted area (WM(+)) presenting improvement in wall movement at loading and 5 segments as infarcted area (WM(-)) presenting no such improvement, and %WT at rest and loading were 29.1±6.2 and 33.2±2.4 for (WM(-)) and 26.8±9.8 and 40.0±12.3 for (WM(+)), indicating a significant increase (p<0.05) at loading. Contractility analysis using MIBI gated SPECT in combined use of DOB-loading was considered as a useful method of examination in view of its reflectionality in the evaluation of the wall movement in DOB-loaded echography and of its high quantitativity. (author)

  11. The need for output-based standards for gas turbines

    International Nuclear Information System (INIS)

    This article examines output-based emission standards based on overall thermal efficiency for combustion sources including gas turbines that are used in combined heat and power applications. The criteria for emission standards are outlined and traditional approaches to emission standards, and efficiency or output-based standards are considered. Issues and challenges related to the drive to ultra low NOx ppm concentration standards for gas turbines are highlighted, and the development of Canadian National Emission guidelines is discussed along with NOx emission target levels, power output allowances, heat recovery allowances, and cost effectiveness of NOx control systems

  12. Anti-rat soluble IL-6 receptor antibody down-regulates cardiac IL-6 and improves cardiac function following trauma-hemorrhage.

    Science.gov (United States)

    Yang, Shaolong; Hu, Shunhua; Choudhry, Mashkoor A; Rue, Loring W; Bland, Kirby I; Chaudry, Irshad H

    2007-03-01

    Although anti-IL-6-mAb down-regulates cardiac IL-6 and attenuates IL-6-mediated cardiac dysfunction following trauma-hemorrhage, it is not known whether blockade of IL-6 receptor will down-regulate cardiac IL-6 and improve cardiac function under those conditions. Six groups of male adult rats (275-325 g) were used: sham/trauma-hemorrhage+vehicle, sham/trauma-hemorrhage+IgG, sham/trauma-hemorrhage+anti-rat sIL-6R. Rats underwent trauma-hemorrhage (removal of 60% of the circulating blood volume and fluid resuscitation after 90 min). Vehicle (V), normal goat IgG or anti-rat sIL-6R (16.7 microg/kg BW) was administered intra-peritoneally in the middle of resuscitation. Two hours later, cardiac function was measured by ICG dilution technique; blood samples collected, cardiomyocytes isolated, and cardiomyocyte nuclei were then extracted. Cardiac IL-6, IL-6R, gp130, IkappaB-alpha/P-IkappaB-alpha, NF-kappaB, and ICAM-1 expressions were measured by immunoblotting. Plasma IL-6 and cardiomyocyte NF-kappaB DNA-binding activity were determined by ELISA. In additional animals, heart harvested and cardiac MPO activity and CINC-1 and -3 were also measured. In another group of rats, cardiac function was measure by microspheres at 24 h following trauma-hemorrhage. Cardiac function was depressed and cardiac IL-6, P-IkappaB-alpha, NF-kappaB and its DNA-binding activity, ICAM-1, MPO activity, and CINC-1 and -3 were markedly increased after trauma-hemorrhage. Moreover, cardiac dysfunction was evident even 24 h after trauma-hemorrhage. Administration of sIL-6R following trauma-hemorrhage: (1) improved cardiac output at 2 h and 24 h (p<0.05); (2) down-regulated both cardiac IL-6 and IL-6R (p<0.05); and (3) attenuated cardiac P-IkappaB-alpha, NF-kappaB, NF-kappaB DNA-binding activity, ICAM-1, CINC-1, -3, and MPO activity (p<0.05). IgG did not significantly influence the above parameters. Thus, IL-6-mediated up-regulation of cardiac NF-kappaB, ICAM-1, CINC-1, -3, and MPO activity likely

  13. Acupuncture Effects on Cardiac Functions Measured by Cardiac Magnetic Resonance Imaging in a Feline Model

    Directory of Open Access Journals (Sweden)

    Jen-Hsou Lin

    2010-01-01

    Full Text Available The usefulness of acupuncture (AP as a complementary and/or alternative therapy in animals is well established but more research is needed on its clinical efficacy relative to conventional therapy, and on the underlying mechanisms of the effects of AP. Cardiac magnetic resonance imaging (CMRI, an important tool in monitoring cardiovascular diseases, provides a reliable method to monitor the effects of AP on the cardiovascular system. This controlled experiment monitored the effect electro-acupuncture (EA at bilateral acupoint Neiguan (PC6 on recovery time after ketamine/xylazine cocktail anesthesia in healthy cats. The CMRI data established the basic feline cardiac function index (CFI, including cardiac output and major vessel velocity. To evaluate the effect of EA on the functions of the autonomic nervous and cardiovascular systems, heart rate, respiration rate, electrocardiogram and pulse rate were also measured. Ketamine/xylazine cocktail anesthesia caused a transient hypertension in the cats; EA inhibited this anesthetic-induced hypertension and shortened the post-anesthesia recovery time. Our data support existing knowledge on the cardiovascular benefits of EA at PC6, and also provide strong evidence for the combination of anesthesia and EA to shorten post-anesthesia recovery time and counter the negative effects of anesthetics on cardiac physiology.

  14. Acupuncture effects on cardiac functions measured by cardiac magnetic resonance imaging in a feline model.

    Science.gov (United States)

    Lin, Jen-Hsou; Shih, Chen-Haw; Kaphle, Krishna; Wu, Leang-Shin; Tseng, Weng-Yih; Chiu, Jen-Hwey; Lee, Tzu-Chi; Wu, Ying-Ling

    2010-06-01

    The usefulness of acupuncture (AP) as a complementary and/or alternative therapy in animals is well established but more research is needed on its clinical efficacy relative to conventional therapy, and on the underlying mechanisms of the effects of AP. Cardiac magnetic resonance imaging (CMRI), an important tool in monitoring cardiovascular diseases, provides a reliable method to monitor the effects of AP on the cardiovascular system. This controlled experiment monitored the effect electro-acupuncture (EA) at bilateral acupoint Neiguan (PC6) on recovery time after ketamine/xylazine cocktail anesthesia in healthy cats. The CMRI data established the basic feline cardiac function index (CFI), including cardiac output and major vessel velocity. To evaluate the effect of EA on the functions of the autonomic nervous and cardiovascular systems, heart rate, respiration rate, electrocardiogram and pulse rate were also measured. Ketamine/xylazine cocktail anesthesia caused a transient hypertension in the cats; EA inhibited this anesthetic-induced hypertension and shortened the post-anesthesia recovery time. Our data support existing knowledge on the cardiovascular benefits of EA at PC6, and also provide strong evidence for the combination of anesthesia and EA to shorten post-anesthesia recovery time and counter the negative effects of anesthetics on cardiac physiology. PMID:18955311

  15. Microwave Transmitter With Multimode Output Section

    Science.gov (United States)

    Hoppe, Daniel J.; Bhanji, Alaudin M.; Cormier, Reginald A.

    1988-01-01

    Output-waveguide structure transports 400 kW of continuous-wave signal power at 34.5 GHz. Transmitter generates 400 kW of continuous-wave (CW) signal power. Main feature of conceptual design of this microwave transmitter is output section. Output waveguide structure includes mode converter, directional coupler, polarization monitor, and corrugated overmoded output section. Output directional pattern suitable for antenna illumination without flared feedhorn.

  16. Low thymic output in the 22q11.2 deletion syndrome measured by CCR9+CD45RA+ T cell counts and T cell receptor rearrangement excision circles

    DEFF Research Database (Denmark)

    Lima, K; Abrahamsen, Gitte Meldgaard; Foelling, I;

    2010-01-01

    -expression of CD3, CD45RA and CCR9 (r=0.84) as well as with the CD4+ and CD8+ T cell subtypes. RTE-related T cell counts also paralleled age-related TREC reductions. CD45RA+ T cells correlated well with absolute counts of CD4+ (r=0.87) and CD8+ (r=0.75) RTE-related T cells. Apart from CD45RA- T cells, all T......Thymic hypoplasia is a frequent feature of the 22q11.2 deletion syndrome, but we know little about patients' age-related thymic output and long-term consequences for their immune system. We measured the expression of T cell receptor rearrangement excision circles (TREC) and used flow cytometry for...... direct subtyping of recent thymic emigrant (RTE)-related T cells in 43 patients (aged 1-54 years; median 9 years) from all over Norway and in age-matched healthy controls. Thymic volumes were estimated by ultrasound in patients. TREC levels correlated well with RTE-related T cells defined by co...

  17. Monitoring and management of right ventricular function following cardiac transplantation

    Directory of Open Access Journals (Sweden)

    F. Wagner

    2011-12-01

    presence of a low cardiac index but preserved systemic pressures and epinephrine in cases of low cardiac output syndrome and systemic hypotension. A useful adjunct to catecholamine therapy is phosphodiesterase-III-inhibitors in the absence of arterial hypotension. Most importantly, pulmonary arterial pressures and right ventricular afterload have to be lowered in pulmonary hypertension compromising right ventricular function. Systemic vasodilators to treat pulmonary hypertension are non-selective and may induce arterial hypotension. This also applies to intravenously administered prostanoids. Inhaled NO in therapeutic doses selectively dilates the pulmonary vasculature without inducing systemic hypotension. To prevent a rebound phenomenon, inhaled NO therapy has to be slowly weaned. To account for the individually different response to inhaled NO, dose titration is recommended with doses of 10–50 ppm NO to lower pulmonary arterial pressures. Inhaled NO has been successfully used for all indications in the treatment of pulmonary hypertension in cardiac surgery. It has proved to be especially effective after implantation of left ventricular assist devices and following heart transplantations. As an alternative therapy, inhalation of aerosolized prostanoids similar to inhaled NO selectively decreases pulmonary arterial pressures.In recent years there has been growing evidence that the orally available phosphodiesterase 5 inhibitor sildenafil may be a useful adjunct to therapy in right ventricular failure. Inhibition of posphodiesterase 5 by sildenafil selectively induces pulmonary vasodilatation without deleterious effects on the systemic circulation. It can also be employed to facilitate weaning heart transplant recipients of inhaled NO, catecholamines and mechanical ventilator support. It has also been reported to have synergistic effects with inhaled NO and may be a treatment option in refractory cases. Potential drug interactions with immunosuppressive drugs have to be

  18. Are output measurements always necessary after CT tube replacement?

    Directory of Open Access Journals (Sweden)

    Paul J Stauduhar

    2014-03-01

    Full Text Available Purpose: TX regulations and the ACR require that CT radiation output be measured within 30 days of major service. The most common major service is tube replacement. We hypothesized that historical QC data could be used instead to determine if output measurements are necessary, reducing the need for costly output measurements.Methods: We reviewed 66 records of tube replacements to determine with what frequency output falls outside specifications. We also conducted an experiment to verify that clinically significant output changes could be identified by comparing image noise in historical QC data with the same data after tube replacement. We used 30 days of historical QC data to establish a baseline noise level and 95% confidence interval (CI for individual noise measurements. To simulate output changes, we acquired phantom images with our QC protocol while manually changing output (mA. We acquired 10 images using the baseline output and 10 images at each different “output”. We evaluated individual images and subsets of images at each “output” to determine if the system was within the manufacturer’s specifications.Results: None of the 66 tube replacements resulted in an output change that exceeded specifications. Analysis of 30 days of historic QC data for our experimental system indicated a mean noise of 5.4 HU with 95% CI of 5.1 ‒ 5.7 HU. When using the mean noise of 10 images acquired at each of the varying outputs, we were able to identify, with 100% accuracy, images acquired at outputs outside manufacturer’s specifications.Conclusion: The results of our review of historical tube replacement data indicated the likelihood of output falling outside manufacturer’s specifications is low. Considering this, it is likely that by using QC data from programs required by regulation and the ACR physicists can reliably verify radiation output stability remotely instead of making physical measurements.--------------------Cite this article

  19. Imaging features of cardiac myxoma

    International Nuclear Information System (INIS)

    Objective: To study the imaging features of cardiac myxoma and their diagnostic values. Methods: Twenty-two patrents with cardiac myxoma were reviewed retrospectively for the clinical, pathologic, and radiologic findings. Posteroanterior and lateral chest radiographs, American Imatron C-150 XP Electron Beam CT examination, and Germany Siemens 1.5T Magnetom Vision MR scan were performed on every patient. Results: (1) Radiographs of 17 patients with left atrial myxoma showed evidence of mitral valve obstruction in 14(82.3%), radiographs of 5 patients with right atrial myxoma demonstrated right atrium enlargement in 3(60%) respectively. (2) CT scans of 22 myxomas demonstrated 18 (81.8%) lesions were hypoattenuated and 4 (19.1%) were isoattenuated relative to the myocardium. Calcification or ossification was seen in 3 patients. All myxomas apart from massive one were found attaching to the atrial septum. Movie mode could dis- play the movement of myxoma across the atrioventicular valves. (3) MRI studies of 22 myxomas showed 19 (86.3%) heterogeneous signal intensity and 3 (13.7%) homogeneous. They exhibited slight high or homogeneous signal intensity with both T1- and T2-weighted sequences, and low signal intensity with cine gradient recalled echo sequences. Point of attachment was visible in 21 (95.4%) cases. Conclusion: The typical radiograph sign of cardiac myxomas is mitral valve obstruction, CT and MR can demonstrate intracavitary lobular masses attacthing to artrial spetum. The latter two kinds of examinations not only provide accurate assessment of the size, location, and attachment point of these lesions, but also have important qualitative diagnostic advantage. (authors)

  20. Influence of gravity on cardiac performance

    Science.gov (United States)

    Pantalos, G. M.; Sharp, M. K.; Woodruff, S. J.; O'Leary, D. S.; Lorange, R.; Everett, S. D.; Bennett, T. E.; Shurfranz, T.

    1998-01-01

    Results obtained by the investigators in ground-based experiments and in two parabolic flight series of tests aboard the NASA KC-135 aircraft with a hydraulic simulator of the human systemic circulation have confirmed that a simple lack of hydrostatic pressure within an artificial ventricle causes a decrease in stroke volume of 20%-50%. A corresponding drop in stroke volume (SV) and cardiac output (CO) was observed over a range of atrial pressures (AP), representing a rightward shift of the classic CO versus AP cardiac function curve. These results are in agreement with echocardiographic experiments performed on space shuttle flights, where an average decrease in SV of 15% was measured following a three-day period of adaptation to weightlessness. The similarity of behavior of the hydraulic model to the human system suggests that the simple physical effects of the lack of hydrostatic pressure may be an important mechanism for the observed changes in cardiac performance in astronauts during the weightlessness of space flight.

  1. Cardiac metastasis from colorectal cancer: A case report

    Institute of Scientific and Technical Information of China (English)

    Pyong Wha Choi; Chul Nam Kim; Sun Hee Chang; Woo Ik Chang; Chang Young Kim; Hyun Min Choi

    2009-01-01

    The heart is an unusual site of metastasis from any malignancy. We report a case of cardiac metastasis from colorectal cancer. A 70-year-old woman was referred with a presumptive diagnosis of sigmoid colon cancer with cardiac myxoma. Two-dimensional echocardiography showed a 4 cm × 4.5 cm mobile mass on the lateral right atrial wall, and computed tomography revealed a low attenuated lobulating mass in the right atrium. The patient underwent anterior resection for sigmoid colon cancer (T4N2). Thereafter, she experienced progressive shortness of breath. Therefore, a cardiac operation was performed 2 wk after the colorectal operation.Histological examination revealed adenocarcinoma,which was identical to the primary lesion. Although twodimensional echocardiography has become the diagnostic test of choice for detecting cardiac tumors, in patients with colorectal cancer showing a cardiac mass, further diagnostic evaluation such as a magnetic resonance imaging might be necessary.

  2. A New Frontier for Cardiac Monitoring

    Science.gov (United States)

    2001-01-01

    CardioDynamics International Corporation (CDIC) has created the BioZ(TM) System through a Small Business Innovation Research (SBIR) award from Johnson Space Center, providing patients and physicians with a cost-effective and highly accurate monitoring system.The BioZ non-invasive heart monitor is based on a technology known as Impedance Cardiography (ICG). BioZ provides the physician with vital information about the heart's ability to deliver blood to the body, the force one's heart exerts with each beat, and the amount of fluid in the chest. Specially designed bioimpedance sensors placed on the neck and chest monitor 12 different parameters, including cardiac output, contractility, systemic vascular resistance, and thoracic fluid content. These sensors monitor the electrical conductivity of the body-information that is converted into blood flow data and is displayed in real time on a monitoring screen. BioZ.com(TM) and BioZ.pc(TM) are two additional products that incorporate the same sensors present in the original BioZ system. The "com" in BioZ.com stands for cardiac output monitor. This fully integrated system is essentially a smaller version of the BioZ, combining the same abilities with a compact, lightweight design, while providing greater portability.

  3. Giant Cardiac Cavernous Hemangioma.

    Science.gov (United States)

    Unger, Eric; Costic, Joseph; Laub, Glenn

    2015-07-01

    We report the case of an asymptomatic giant cardiac cavernous hemangioma in a 71-year-old man. The intracardiac mass was discovered incidentally during surveillance for his prostate cancer; however, the patient initially declined intervention. On presentation to our institution 7 years later, the lesion had enlarged significantly, and the patient consented to excision. At surgery, an 8 × 6.5 × 4.8 cm intracardiac mass located on the inferior heart border was excised with an intact capsule through a median sternotomy approach. The patient had an uneventful postoperative course. We discuss the diagnostic workup, treatment, and characteristics of this rare cardiac tumor. PMID:26140782

  4. Random output and hospital performance.

    Science.gov (United States)

    Barros, Pedro Pita

    2003-11-01

    Many countries are under pressure to reform health care financing and delivery. Hospital care is one part of the health system that is under scrutiny. Private management initiatives are a possible way to increase efficiency in health care delivery. This motivates the interest in developing methodologies to assess hospital performance, recognizing hospitals as a different sort of firm. We present a simple way to describe hospital production: hospital output as a change in the distribution of survival probabilities. This output definition allows us to separate hospital production from patients' characteristics. The notion of "better performance" has a precise meaning: (first-order) stochastic dominance of a distribution of survival probabilities over another distribution. As an illustration, we compare, for an important DRG, private and public management and find that private management performs better, mainly in the range of high-survival probabilities. The measured performance difference cannot be attributed to input prices or to economies of scale and/or scope. It reflects pure technological and organisational differences. PMID:14686628

  5. Radiography in cardiology [cardiac disorders, cardiac insufficiency

    International Nuclear Information System (INIS)

    The diagnostic procedure in cardiology nearly always requires an X-ray examination of the thorax. This examination is very informative when it is correctly performed and interpreted. The radiographs need to be read precisely and comprehensively: this includes the evaluation of the silhouette of the heart (size, form and position) as well as the examination of extra-cardiac thoracic structures allowing among other things to search for signs of cardiac insufficiency. The conclusion of the X-ray examination can be drawn after having brought together information concerning the case history, the clinical examination and the study of the radiographs. The radiologist finds himself in one of three situations: (1) the information provided by the X-ray pictures is characteristic of a disease and permits a diagnosis, (2) the X-ray pictures indicate a group of hypotheses; further complementary tests could be useful and (3) the X-ray pictures provide ambiguous even contradictory information; it is necessary to complete the radiological examination by other techniques such as an ultrasonographic study of the heart

  6. Serum myoglobin after cardiac catheterisation.

    OpenAIRE

    McComb, J. M.; McMaster, E A

    1982-01-01

    Study of 80 consecutive patients undergoing elective diagnostic cardiac catheterisation showed that after the procedure 25 (31%) developed myoglobinaemia. This was attributed to complications of the catheterisation in two. The remaining 23 had received premedication by intramuscular injection. In patients without intramuscular injections myoglobinaemia did not occur after uncomplicated cardiac catheterisation. The study did not support the proposition that cardiac catheterisation results in m...

  7. Methylene blue: potential use of an antique molecule in vasoplegic syndrome during cardiac surgery.

    Science.gov (United States)

    Lenglet, Sébastien; Mach, François; Montecucco, Fabrizio

    2011-12-01

    Vasoplegic syndrome is a common complication of cardiopulmonary bypass, appearing with an incidence ranging between 5 and 25%. It is characterized by significant hypotension, high or normal cardiac output and low systemic vascular resistance. This syndrome is hypothesized to be caused by the inflammation-mediated dysregulation of endothelial homeostasis and subsequent endothelial dysfunction. In vasoplegic syndrome, the inhibition of the nitric oxide/cyclic guanosine monophosphate pathway with concomitant administration with traditional ionotropes may represent a promising therapeutic option. Methylene blue, an inhibitor of nitric oxide synthase and guanylate cyclase, may contribute to the improvement of refractory hypotension associated with endothelial dysfunction in vasoplegia. In this article, we will update evidence on the potential therapeutic use of methylene blue in vasoplegic syndrome. PMID:22103871

  8. Preventing Inductive Output Impedance of High-Frequency Emitter Follower Stages

    Directory of Open Access Journals (Sweden)

    R. C. Tozer

    1997-04-01

    Full Text Available Large output inductance is one of major issues of high-frequency emitter follower design. The most often suggested technique to reduce its value is the decreasing of AC transconductance which offers small output inductance at the expense of loosing low output resistance. The paper presents a different approach; it is shown that output inductance can be completely cancelled while keeping very low output resistance by introducing a pole at the input node which may be more suitable in many types of design. Complete analytical evaluation based on the full hybrid-n model of the bipolar transistor device is given.

  9. Multi-output DC-DC converters based on diode-clamped converters configuration

    DEFF Research Database (Denmark)

    Nami, A.; Zare, F.; Ghosh, A.;

    2010-01-01

    This study presents a new DC DC multi-output boost (MOB) converter which can share its total output between different series of output voltages for low- and high-power applications. This configuration can be utilised instead of several single output power supplies. This is a compatible topology for...... a diode-clamed inverter in the grid connection systems, where boosting low rectified output-voltage and series DC link capacitors is required. To verify the proposed topology, steady-state and dynamic analyses of a MOB converter are examined. A simple control strategy has been proposed to...

  10. Dependency of blood pressure upon cardiac filling in patients with severe postural hypotension

    DEFF Research Database (Denmark)

    Mehlsen, J; Haedersdal, C; Stokholm, K H

    1994-01-01

    vasoconstriction. The reduction in cardiac output resulted from reductions in left ventricular end-diastolic volumes with unchanged left ventricular ejection fractions and only moderate increments in heart rate. The study was demonstrated that blood pressure is strongly dependent upon cardiac filling in severe......Autonomic denervation of the vascular bed results theoretically in a stronger dependency of blood pressure upon intravascular volume, and the study described aimed at an investigation of the relation between cardiac filling and arterial blood pressure in patients with severe postural hypotension....... Seven patients were studied during head-up tilt at three different tilt angles using intra-arterial blood pressure recordings and estimates of left ventricular volumes by radioisotope ventriculography. Blood pressure fell dramatically during head-up tilt due to reductions in cardiac output unopposed by...

  11. Integration of TMVA Output into Jupyter notebooks

    CERN Document Server

    Saliji, Albulena

    2016-01-01

    The purpose of this report is to describe the work that I have been doing during these past eight weeks as a Summer Student at CERN. The task which was assigned to me had to do with the integration of TMVA Output into Jupyter notebooks. In order to integrate the TMVA Output into the Jupyter notebook, first, improvement of the TMVA Output in the terminal was required. Once the output was improved, it needed to be transformed into HTML output and at the end it would be possible to integrate that output into the Jupyter notebook.

  12. Public Investment and Output Performance: Evidence from Nigeria

    Directory of Open Access Journals (Sweden)

    Aregbeyen Omo

    2016-05-01

    Full Text Available This study examined the direct/indirect long-run relationships and dynamic interactions between public investment (PI and output performance in Nigeria using annual data spanning 1970-2010. A macro-econometric model derived from Keynes’ income-expenditure framework was employed. The model was disaggregated into demand and supply sides to trace the direct and indirect effects of PI on aggregate output. The direct supply side effect was assessed using the magnitude of PI multiplier coefficient, while the indirect effect of PI on the demand side was evaluated with marginal propensity to consume, accelerator coefficient and import multiplier. The results showed relatively less strong direct effect of PI on aggregate output, while the indirect effects were stronger with the import multiplier being the most pronounced. This is attributed to declining capital expenditure, poor implementation and low quality of PI projects due to widespread corruption. By and large, we concluded that PI exerted considerable influence on aggregate output.

  13. Hepato-cardiac disorders

    Institute of Scientific and Technical Information of China (English)

    Yasser; Mahrous; Fouad; Reem; Yehia

    2014-01-01

    Understanding the mutual relationship between the liver and the heart is important for both hepatologists and cardiologists. Hepato-cardiac diseases can be classified into heart diseases affecting the liver, liver diseases affecting the heart, and conditions affecting the heart and the liver at the same time. Differential diagnoses of liver injury are extremely important in a cardiologist’s clinical practice calling for collaboration between cardiologists and hepatologists due to the many other diseases that can affect the liver and mimic haemodynamic injury. Acute and chronic heart failure may lead to acute ischemic hepatitis or chronic congestive hepatopathy. Treatment in these cases should be directed to the primary heart disease. In patients with advanced liver disease, cirrhotic cardiomyopathy may develop including hemodynamic changes, diastolic and systolic dysfunctions, reduced cardiac performance and electrophysiological abnormalities. Cardiac evaluation is important for patients with liver diseases especially before and after liver transplantation. Liver transplantation may lead to the improvement of all cardiac changes and the reversal of cirrhotic cardiomyopathy. There are systemic diseases that may affect both the liver and the heart concomitantly including congenital, metabolic and inflammatory diseases as well as alcoholism. This review highlights these hepatocardiac diseases

  14. Primary cardiac tumors

    International Nuclear Information System (INIS)

    Cardiac tumors happen to be among the less known pathologies without clear treatment standards. Even one decade ago most of the cardiac tumor diagnosis were made post mortem, and only reports of isolated cases could be found in the literature, showing the lack of interest in the investigation of these pathologies by cardiology and cardiovascular surgery specialists. With the development of echocardiography and of cardiovascular surgery, more cases of primary and metastatic cardiac tumors have been diagnosed. Many cases have been treated by palliative or curative surgical interventions, thus increasing the reports in the world literature and the experience in this field, and pointing out the real incidence of these pathologies, not being as bizarre as it had been considered. a revision of the literature will be made, in which the frequency and the suggested interventions will be reported, as well as the cases of cardiac pathology in two cardiovascular centers of the country known by the author. The echocardiographic, pathologic and histological characteristics of the representative cases will be presented, without a greater evidence level, due to the problem's incidence and the few cases reported by these centers

  15. Cardiac MRI tagging

    International Nuclear Information System (INIS)

    Cardiac MRI tagging is an original technique based upon the perturbation of the magnetization of determined regions of the myocardium (tags). The motion of the tags accurately reflects the deformation of the underlying tissue. Data analysis requires special techniques to reconstruct the 3D motion of the heart, and to evaluate the myocardial strain, locally and throughout the whole heart. (authors)

  16. Automatic Implantable Cardiac Defibrillator

    Medline Plus

    Full Text Available ... Over the next hour you'll see the implantation of an automated implantable cardiac defibrillator. The surgery ... evening we're going to be discussing the implantation of a defibrillator. It’s a battery-powered implantable ...

  17. Cardiac effects of vasopressin.

    Science.gov (United States)

    Pelletier, Jean-Sébastien; Dicken, Bryan; Bigam, David; Cheung, Po-Yin

    2014-07-01

    Vasopressin is an essential hormone involved in the maintenance of cardiovascular homeostasis. It has been in use therapeutically for many decades, with an emphasis on its vasoconstrictive and antidiuretic properties. However, this hormone has a ubiquitous influence and has specific effects on the heart. Although difficult to separate from its powerful vascular effects in the clinical setting, a better understanding of vasopressin's direct cardiac effects could lead to its more effective clinical use for a variety of shock states by maximizing its therapeutic benefit. The cardiac-specific effects of vasopressin are complex and require further elucidation. Complicating our understanding include the various receptors and secondary messengers involved in vasopressin's effects, which may lead to various results based on differing doses and varying environmental conditions. Thus, there have been contradictory reports on vasopressin's action on the coronary vasculature and on its effect on inotropy. However, beneficial results have been found and warrant further study to expand the potential therapeutic role of vasopressin. This review outlines the effect of vasopressin on the coronary vasculature, cardiac contractility, and on hypertrophy and cardioprotection. These cardiac-specific effects of vasopressin represent an interesting area for further study for potentially important therapeutic benefits. PMID:24621650

  18. Cardiac pacemaker power sources

    International Nuclear Information System (INIS)

    A review of chemical and radioisotope batteries used in cardiac pacemakers is presented. The battery systems are examined in terms of longevity, reliability, cost, size and shape, energy density, weight, internal resistance versus time, end-of-life voltage, chemical compatibility, and potential failure mechanisms

  19. Moore's law, Dabbawalas, and pediatric cardiac care in Sri Lanka.

    Science.gov (United States)

    Samarasinghe, Duminda

    2015-01-01

    Sri Lanka is an island nation in Indian Ocean that provides free healthcare to all citizens through government healthcare system. It has commendable health indices in the region. Pediatric cardiac services have rapidly progressed over past few years helping to further bring down infant and under-five mortality rates. Lady Ridgeway Hospital for Children (LRH) is the only tertiary care referral center for children with heart disease in the country. Currently it performs approximately 1,000 cardiac catheterizations and 1,000 cardiac surgeries every year. Target is to double the surgical output to treat all children with heart diseases in a timely and appropriate manner. Being a middle-income country, this is not an easy task. Technology used in diagnosis and treatment of congenital heart diseases is rapidly advancing with its price tag. In such a setting, it is challenging to proceed to achieve this target in a resource-limited environment. PMID:26085764

  20. Characterization of glutamatergic neurons in the rat atrial intrinsic cardiac ganglia that project to the cardiac ventricular wall.

    Science.gov (United States)

    Wang, Ting; Miller, Kenneth E

    2016-08-01

    The intrinsic cardiac nervous system modulates cardiac function by acting as an integration site for regulating autonomic efferent cardiac output. This intrinsic system is proposed to be composed of a short cardio-cardiac feedback control loop within the cardiac innervation hierarchy. For example, electrophysiological studies have postulated the presence of sensory neurons in intrinsic cardiac ganglia (ICG) for regional cardiac control. There is still a knowledge gap, however, about the anatomical location and neurochemical phenotype of sensory neurons inside ICG. In the present study, rat ICG neurons were characterized neurochemically with immunohistochemistry using glutamatergic markers: vesicular glutamate transporters 1 and 2 (VGLUT1; VGLUT2), and glutaminase (GLS), the enzyme essential for glutamate production. Glutamatergic neurons (VGLUT1/VGLUT2/GLS) in the ICG that have axons to the ventricles were identified by retrograde tracing of wheat germ agglutinin-horseradish peroxidase (WGA-HRP) injected in the ventricular wall. Co-labeling of VGLUT1, VGLUT2, and GLS with the vesicular acetylcholine transporter (VAChT) was used to evaluate the relationship between post-ganglionic autonomic neurons and glutamatergic neurons. Sequential labeling of VGLUT1 and VGLUT2 in adjacent tissue sections was used to evaluate the co-localization of VGLUT1 and VGLUT2 in ICG neurons. Our studies yielded the following results: (1) ICG contain glutamatergic neurons with GLS for glutamate production and VGLUT1 and 2 for transport of glutamate into synaptic vesicles; (2) atrial ICG contain neurons that project to ventricle walls and these neurons are glutamatergic; (3) many glutamatergic ICG neurons also were cholinergic, expressing VAChT; (4) VGLUT1 and VGLUT2 co-localization occurred in ICG neurons with variation of their protein expression level. Investigation of both glutamatergic and cholinergic ICG neurons could help in better understanding the function of the intrinsic cardiac

  1. Cardiac surgery outcomes.

    Science.gov (United States)

    Halpin, Linda S; Barnett, Scott D; Beachy, Jim

    2003-01-01

    Accrediting organizations and payers are demanding valid and reliable data that demonstrate the value of services. Federal agencies, healthcare industry groups, and healthcare watchdog groups are increasing the demand for public access to outcomes data. A new and growing outcomes dynamic is the information requested by prospective patients in an increasingly consumer-oriented business. Patients demand outcomes, and resources are developing to meet these demands. Physicians are increasingly confronted with requests for information about their mortality and morbidity rates, malpractice suits, and disciplinary actions received. For example, in Virginia, prospective patients have access to data provided by the nonprofit group Virginia Health Information. After numerous resolutions by the Virginia Senate since 1999, the prospective Virginia medical consumer now has access to several annual publications: Virginia Hospitals: A Consumer's Guide, 1999 Annual Report and Strategic Plan Update, and the 1999 Industry Report: Virginia Hospitals and Nursing Facilities. Consumers have access to cardiac outcomes data stratified by hospital, gender, and cardiac service line (cardiac surgery, noninvasive cardiology, and invasive cardiology). This is particularly relevant to IHI because Virginia Health Information specifically targets cardiac care. IHI has a sizable investment in cardiovascular outcomes and has found outcomes measurement and research are key to providing quality care. IHI's goal is to move from an outcomes management model to a disease management model. The hope is to incorporate all aspects of the patient's continuum of care, from preoperative and diagnostic services through cardiac interventions to postoperative rehabilitation. Furthermore, every step along the way will be supported with functional status and quality of life assessments. Although these goals are ambitious and expensive, the return on investment is high. PMID:14618772

  2. High Altitude and Intracardiac Devices(Pacemaker and Intracardiac Defibrillator andCardiac Resynchronisation Therapy)

    OpenAIRE

    Gürsoy, Mustafa Ozan; Yıldız, Banu Şahin; Yıldız, Mustafa

    2013-01-01

    Cardiovascular system responds to high altitude short after exposure. Hypoxia induces increase in heart rate, myocardial contractility, and cardiac output. This may have clinical implications in patients with underlying heart disease such as coronary artery disease, heart failure and rhythm disorders. Past studies have showed that patients may experience altitude-induced arrhythmias. However, there are conflicting data for patients with cardiac devices such as permanent pacemaker, intracardia...

  3. Evidence for increased cardiac compliance during exposure to simulated microgravity

    Science.gov (United States)

    Koenig, S. C.; Convertino, V. A.; Fanton, J. W.; Reister, C. A.; Gaffney, F. A.; Ludwig, D. A.; Krotov, V. P.; Trambovetsky, E. V.; Latham, R. D.

    1998-01-01

    We measured hemodynamic responses during 4 days of head-down tilt (HDT) and during graded lower body negative pressure (LBNP) in invasively instrumented rhesus monkeys to test the hypotheses that exposure to simulated microgravity increases cardiac compliance and that decreased stroke volume, cardiac output, and orthostatic tolerance are associated with reduced left ventricular peak dP/dt. Six monkeys underwent two 4-day (96 h) experimental conditions separated by 9 days of ambulatory activities in a crossover counterbalance design: 1) continuous exposure to 10 degrees HDT and 2) approximately 12-14 h per day of 80 degrees head-up tilt and 10-12 h supine (control condition). Each animal underwent measurements of central venous pressure (CVP), left ventricular and aortic pressures, stroke volume, esophageal pressure (EsP), plasma volume, alpha1- and beta1-adrenergic responsiveness, and tolerance to LBNP. HDT induced a hypovolemic and hypoadrenergic state with reduced LBNP tolerance compared with the control condition. Decreased LBNP tolerance with HDT was associated with reduced stroke volume, cardiac output, and peak dP/dt. Compared with the control condition, a 34% reduction in CVP (P = 0.010) and no change in left ventricular end-diastolic area during HDT was associated with increased ventricular compliance (P = 0.0053). Increased cardiac compliance could not be explained by reduced intrathoracic pressure since EsP was unaltered by HDT. Our data provide the first direct evidence that increased cardiac compliance was associated with headward fluid shifts similar to those induced by exposure to spaceflight and that reduced orthostatic tolerance was associated with lower cardiac contractility.

  4. Risk factors and the effect of cardiac resynchronization therapy on cardiac and non-cardiac mortality in MADIT-CRT

    DEFF Research Database (Denmark)

    Perkiomaki, Juha S; Ruwald, Anne-Christine; Kutyifa, Valentina;

    2015-01-01

    causes, 108 (63.9%) deemed cardiac, and 61 (36.1%) non-cardiac. In multivariate analysis, increased baseline creatinine was significantly associated with both cardiac and non-cardiac deaths [hazard ratio (HR) 2.97, P ...AIMS: To understand modes of death and factors associated with the risk for cardiac and non-cardiac deaths in patients with cardiac resynchronization therapy with implantable cardioverter-defibrillator (CRT-D) vs. implantable cardioverter-defibrillator (ICD) therapy, which may help clarify...

  5. Computational Complexity of Input/Output Logic

    OpenAIRE

    Sun, Xin; Ambrossio, Diego Agustin

    2015-01-01

    Input/output logics are abstract structures designed to represent conditional norms. The complexity of input/output logic has been sparsely developed. In this paper we study the complexity of input/output logics. We show that the lower bound of the complexity of the fulfillment problem of 4 input/output logics is coNP, while the upper bound is either coNP or P^NP.

  6. Exceptional cardiac anoxia tolerance in tilapia (Oreochromis hybrid).

    Science.gov (United States)

    Lague, Sabine L; Speers-Roesch, Ben; Richards, Jeffrey G; Farrell, Anthony P

    2012-04-15

    Anoxic survival requires the matching of cardiac ATP supply (i.e. maximum glycolytic potential, MGP) and demand (i.e. cardiac power output, PO). We examined the idea that the previously observed in vivo downregulation of cardiac function during exposure to severe hypoxia in tilapia (Oreochromis hybrid) represents a physiological strategy to reduce routine PO to within the heart's MGP. The MGP of the ectothermic vertebrate heart has previously been suggested to be ∼70 nmol ATP s(-1) g(-1), sustaining a PO of ∼0.7 mW g(-1) at 15°C. We developed an in situ perfused heart preparation for tilapia (Oreochromis hybrid) and characterized the routine and maximum cardiac performance under both normoxic (>20 kPa O(2)) and severely hypoxic perfusion conditions (tilapia heart maintained a routine normoxic cardiac output (Q) and PO under all hypoxic conditions, a result that contrasts with the hypoxic cardiac downregulation previously observed in vivo under less severe conditions. Thus, we conclude that the in vivo downregulation of routine cardiac performance in hypoxia is not needed in tilapia to balance cardiac energy supply and demand. Indeed, the MGP of the tilapia heart proved to be quite exceptional. Measurements of myocardial lactate efflux during severe hypoxia were used to calculate the MGP of the tilapia heart. The MGP was estimated to be 172 nmol ATP s(-1) g(-1) at 22°C, and allowed the heart to generate a PO(max) of at least ∼3.1 mW g(-1), which is only 30% lower than the PO(max) observed with normoxia. Even with this MGP, the additional challenge of acidosis during severe hypoxia decreased maximum ATP turnover rate and PO(max) by 30% compared with severe hypoxia alone, suggesting that there are probably direct effects of acidosis on cardiac contractility. We conclude that the high maximum glycolytic ATP turnover rate and levels of PO, which exceed those measured in other ectothermic vertebrate hearts, probably convey a previously unreported anoxia tolerance

  7. Probabilistic Output Analysis by Program Manipulation

    DEFF Research Database (Denmark)

    Rosendahl, Mads; Kirkeby, Maja Hanne

    The aim of a probabilistic output analysis is to derive a probability distribution of possible output values for a program from a probability distribution of its input. We present a method for performing static output analysis, based on program transformation techniques. It generates a probability...

  8. Nonlinear internal models for output regulation

    OpenAIRE

    Byrnes, C. I.; Isidori, A.

    2003-01-01

    In this paper we show how nonlinear internal models can be effectively used in the design of output regulators for nonlinear systems. This result provides a significant enhancement of the non-equilibrium theory for output regulation, which we have presented in the recent paper entitled "Limit Sets, Zero Dynamics, and Internal Models in the Problem of Nonlinear Output Regulation".

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-09-15

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

  10. Psychosocial aspects in cardiac rehabilitation

    DEFF Research Database (Denmark)

    Pogosova, N. V.; Saner, H.; Pedersen, S. S.;

    2015-01-01

    A large body of empirical research shows that psychosocial risk factors (PSRFs) such as low socio-economic status, social isolation, stress, type-D personality, depression and anxiety increase the risk of incident coronary heart disease (CHD) and also contribute to poorer health- related quality...... of life (HRQoL) and prognosis in patients with establishedCHD. PSRFs may also act as barriers to lifestyle changes and treatment adherence and may moderate the effects of cardiac rehabilitation (CR). Furthermore, there appears to be a bidirectional interaction between PSRFs and the cardiovascular system....... Stress, anxiety and depression affect the cardiovascular system through immune, neuroendocrine and behavioural pathways. In turn, CHD and its associated treatments may lead to distress in patients, including anxiety and depression. In clinical practice, PSRFs can be assessed with single-item screening...

  11. Psychosocial aspects in cardiac rehabilitation

    DEFF Research Database (Denmark)

    Pogosova, Nana; Saner, Hugo; Pedersen, Susanne S.;

    2015-01-01

    A large body of empirical research shows that psychosocial risk factors (PSRFs) such as low socio-economic status, social isolation, stress, type-D personality, depression and anxiety increase the risk of incident coronary heart disease (CHD) and also contribute to poorer health-related quality...... of life (HRQoL) and prognosis in patients with established CHD. PSRFs may also act as barriers to lifestyle changes and treatment adherence and may moderate the effects of cardiac rehabilitation (CR). Furthermore, there appears to be a bidirectional interaction between PSRFs and the cardiovascular system....... Stress, anxiety and depression affect the cardiovascular system through immune, neuroendocrine and behavioural pathways. In turn, CHD and its associated treatments may lead to distress in patients, including anxiety and depression. In clinical practice, PSRFs can be assessed with single-item screening...

  12. Transesophageal Doppler reliably tracks changes in cardiac output in comparison with intermittent pulmonary artery thermodilution in cardiac surgery patients

    DEFF Research Database (Denmark)

    Møller-Sørensen, Hasse; Cordtz, Johan Joakim; Østergaard, Morten;

    2016-01-01

    completed the study. Each patient were placed in the following successive positions: (1) supine, (2) head-down tilt, (3) head-up tilt, (4) supine, (5) supine with phenylephrine administration, (6) pace heart rate 80 beats per minute (bpm), (7) pace heart rate 110 bpm. The agreement of compared data...

  13. Diagnosis and treatment of cardiac sarcoidosis.

    Science.gov (United States)

    Kusano, Kengo F; Satomi, Kazuhiro

    2016-02-01

    Sarcoidosis is a systemic granulomatous disease of unknown aetiology. The frequency of cardiac involvement (cardiac sarcoidosis (CS)) varies in the different geographical regions, but it has been reported that it is an absolutely important prognostic factor in this disease. Complete atrioventricular block is the most common, and ventricular tachycardia/ventricular fibrillation the second most common arrhythmia in this disease, both of which are associated with cardiac sudden death. Diagnosing CS is sometimes difficult because of the non-specific ECG and echocardiographic findings, and CS is sometimes misdiagnosed as dilated cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy or an idiopathic ventricular aneurysm, and therefore, endomyocardial biopsy is important, but has a low sensitivity. Another problem is the recognition of isolated types of CS. Recently, MRI and (18)F-fluorodeoxyglucose positron emission tomography have been demonstrated to be useful tools for the non-invasive diagnosis of CS as well as therapeutic evaluation tools, but are still unsatisfactory. Treatment of CS is usually done by corticosteroid therapy to control inflammation, prevent fibrosis and protect from any deterioration of the cardiac function, but the long-term outcome is still in debate. Despite the advancement of non-pharmacological approaches for CS (pacing, defibrillators and catheter ablation) to improve the prognosis, there are still many issues remaining to resolve diagnosing and managing CS. Here, we attempt a review of the clinical evidence, with special focus on the current understanding of this disease and showing the current strategies and remaining problems of diagnosing and managing CS. PMID:26643814

  14. A Preliminary Study of the Cardiac Magnetic Resonance Multi-low-b DWI Technology%多个低b值DWI技术在心脏成像中的初步研究

    Institute of Scientific and Technical Information of China (English)

    刘明熙; 张挽时; 张子衡; 孟利民; 龚万沣; 刘洁; 方红; 王萍

    2016-01-01

    目的:初步研究多个低b值DWI技术在心脏检查中的成像技术和成像特点。方法对符合入组和排除条件的已签署知情同意书的30例健康志愿者行3.0T CMR Cine电影、T2WI和多b值DWI序列扫描,探讨此序列临床应用的可行性,统计分析心肌在各节段、不同供血区、年龄和性别中有无差异,并讨论行DWI序列扫描时,选择何种b值能够更好地反映心肌血流灌注情况。结果当b=20、60 s/mm2时,图像质量较好。健康志愿者各节段心肌ADC值不全相等(F=6.315,P<0.001)。左前降支供血区,右冠状动脉供血区和左旋支供血区ADC值有差异(F=27.804,P<0.001),分别为(0.01186±0.00422)mm2/s,(0.01032±0.00333)mm2/s和(0.00902±0.00248)mm2/s。从基底部到心尖部,心肌平均ADC值无差异。结论多个低b值DWI技术在CMR检查中具有较好的可行性和可重复性。健康志愿者各节段心肌ADC值存在节段性差异。当b=20,60 s/mm2(<100 s/mm2)时,图像质量较好,可能提示此DWI图像可更好地显示心肌血流灌注特点,为今后选择合理b值进行相关研究提供参考。%Objective To investigate the imaging technology and characteristics of cardiac magnetic resonance (CMR) multi-low-b DWI technology.Methods With a 3.0T magnetic resonance imaging (MRI) system, cardiovascular magnetic imaging, including MR Cine, T2WI and multi-low-b DWI technology, was performed in 30 healthy volunteers who had given written informed consent to investigate the clinical feasibility of multi-low-b DWI technology and to explore whether ADC values in different segmental myocardium, differentblood supply areas, different age-groups and gender were similar or not. A discussion was made on whichb value shouldbe selected tobetter relfect the perfusion of myocardium when using DWI technology to scan cardiac structure.Results The image quality of multi-low-b DWI technology wasbetter when theb

  15. Model output: fact or artefact?

    Science.gov (United States)

    Melsen, Lieke

    2015-04-01

    As a third-year PhD-student, I relatively recently entered the wonderful world of scientific Hydrology. A science that has many pillars that directly impact society, for example with the prediction of hydrological extremes (both floods and drought), climate change, applications in agriculture, nature conservation, drinking water supply, etcetera. Despite its demonstrable societal relevance, hydrology is often seen as a science between two stools. Like Klemeš (1986) stated: "By their academic background, hydrologists are foresters, geographers, electrical engineers, geologists, system analysts, physicists, mathematicians, botanists, and most often civil engineers." Sometimes it seems that the engineering genes are still present in current hydrological sciences, and this results in pragmatic rather than scientific approaches for some of the current problems and challenges we have in hydrology. Here, I refer to the uncertainty in hydrological modelling that is often neglected. For over thirty years, uncertainty in hydrological models has been extensively discussed and studied. But it is not difficult to find peer-reviewed articles in which it is implicitly assumed that model simulations represent the truth rather than a conceptualization of reality. For instance in trend studies, where data is extrapolated 100 years ahead. Of course one can use different forcing datasets to estimate the uncertainty of the input data, but how to prevent that the output is not a model artefact, caused by the model structure? Or how about impact studies, e.g. of a dam impacting river flow. Measurements are often available for the period after dam construction, so models are used to simulate river flow before dam construction. Both are compared in order to qualify the effect of the dam. But on what basis can we tell that the model tells us the truth? Model validation is common nowadays, but validation only (comparing observations with model output) is not sufficient to assume that a

  16. Evolution of elderly patients who underwent cardiac surgery with cardiopulmonary bypass

    Directory of Open Access Journals (Sweden)

    Alain Moré Duarte

    2016-01-01

    Full Text Available Introduction: There is a steady increase in the number of elderly patients with severe cardiovascular diseases who require a surgical procedure to recover some quality of life that allows them a socially meaningful existence, despite the risks.Objectives: To analyze the behavior of elderly patients who underwent cardiac surgery with cardiopulmonary bypass.Method: A descriptive, retrospective, cross-sectional study was conducted with patients over 65 years of age who underwent surgery at the Cardiocentro Ernesto Che Guevara, in Santa Clara, from January 2013 to March 2014.Results: In the study, 73.1% of patients were men; and there was a predominance of subjects between 65 and 70 years of age, accounting for 67.3%. Coronary artery bypass graft was the most prevalent type of surgery and had the longest cardiopulmonary bypass times. Hypertension was present in 98.1% of patients. The most frequent postoperative complications were renal dysfunction and severe low cardiac output, with 44.2% and 34.6% respectively.Conclusions: There was a predominance of men, the age group of 65 to 70 years, hypertension, and patients who underwent coronary artery bypass graft with prolonged cardiopulmonary bypass. Renal dysfunction was the most frequent complication.

  17. Cardiac arrest in children

    Directory of Open Access Journals (Sweden)

    Tress Erika

    2010-01-01

    Full Text Available Major advances in the field of pediatric cardiac arrest (CA were made during the last decade, starting with the publication of pediatric Utstein guidelines, the 2005 recommendations by the International Liaison Committee on Resuscitation, and culminating in multicenter collaborations. The epidemiology and pathophysiology of in-hospital and out-of-hospital CA are now well described. Four phases of CA are described and the term "post-cardiac arrest syndrome" has been proposed, along with treatment goals for each of its four phases: immediate post-arrest, early post-arrest, intermediate and recovery phase. Hypothermia is recommended to be considered as a therapy for post-CA syndrome in comatose patients after CA, and large multicenter prospective studies are underway. We reviewed landmark articles related to pediatric CA published during the last decade. We present the current knowledge of epidemiology, pathophysiology and treatment of CA relevant to pre-hospital and acute care health practitioners.

  18. Cardiac arrest in children.

    Science.gov (United States)

    Tress, Erika E; Kochanek, Patrick M; Saladino, Richard A; Manole, Mioara D

    2010-07-01

    Major advances in the field of pediatric cardiac arrest (CA) were made during the last decade, starting with the publication of pediatric Utstein guidelines, the 2005 recommendations by the International Liaison Committee on Resuscitation, and culminating in multicenter collaborations. The epidemiology and pathophysiology of in-hospital and out-of-hospital CA are now well described. Four phases of CA are described and the term "post-cardiac arrest syndrome" has been proposed, along with treatment goals for each of its four phases: immediate post-arrest, early post-arrest, intermediate and recovery phase. Hypothermia is recommended to be considered as a therapy for post-CA syndrome in comatose patients after CA, and large multicenter prospective studies are underway. We reviewed landmark articles related to pediatric CA published during the last decade. We present the current knowledge of epidemiology, pathophysiology and treatment of CA relevant to pre-hospital and acute care health practitioners. PMID:20930971

  19. Cardiac adaptations of bullfrog tadpoles in response to chytrid infection.

    Science.gov (United States)

    Salla, Raquel Fernanda; Gamero, Fernando Urban; Ribeiro, Larissa Rodrigues; Rizzi, Gisele Miglioranza; Medico, Samuel Espinosa Dal; Rissoli, Rafael Zanelli; Vieira, Conrado Augusto; Silva-Zacarin, Elaine Cristina Mathias; Leite, Domingos Silva; Abdalla, Fábio Camargo; Toledo, Luis Felipe; Costa, Monica Jones

    2015-08-01

    The chytrid fungus Batrachochytrium dendrobatidis (Bd) can result in heart failure in Bd-susceptible species. Since Bd infection generally does not cause mortality in North American bullfrogs, the aim of this work was to verify whether this species presents any cardiac adaptation that could improve the tolerance to the fungus. Thus, we analyzed tadpoles' activity level, relative ventricular mass, ventricle morphology, in loco heart frequency, and in vitro cardiac function. The results indicate that infected animals present an increase in both ventricular relative mass and in myofibrils' incidence, which accompanied the increase in myocytes' diameter. Such morphological alterations enabled an increase in the in vitro twitch force that, in vivo, would result in elevation of the cardiac stroke volume. This response requires much less energy expenditure than an elevation in heart frequency, but still enables the heart to pump a higher volume of blood per minute (i.e., an increase in cardiac output). As a consequence, the energy saved in the regulation of the cardiac function of Bd-infected tadpoles can be employed in other homeostatic adjustments to avoid the lethal effect of the fungus. Whether other species present this ability, and to what extent, remains uncertain, but such possible interspecific variability might explain different mortality rates among different species of Bd-infected amphibians. PMID:26055358

  20. A kind of output voltage compensation design of low-voltage and high-current dc power supply%一种低压大电流直流电源的输出电压补偿设计

    Institute of Scientific and Technical Information of China (English)

    谢记华; 张锦鹏; 王金芳

    2015-01-01

    This paper is based on a kind of low-voltage&high-current power supply designed by VICOR DC-DC converter, Through sampling the loading point voltage and applying feedback circuit to adjust the voltage of converter to compensate the drop of the load in high current transmission, so as to achieve the stability of loading point voltage. This paper analyses the basic principle of compensation circuit in detail, introduces the component selection method and proves the feasibility of the circuit by designing and testing voltage compensation circuit.%文中基于一种采用VICOR DC-DC转换器设计的低压大电流直流电源,通过采样负载点电压,外加反馈电路来调节转换器输出电压,以补偿在大电流传输时负载线上的电压降,从而达到稳定负载点电压的目的。本文详细分析了电压补偿电路的原理,介绍了元器件选择方法,并通过电压补偿电路的设计和测试验证了该电路的可行性。

  1. DETERMINANTS OF AGRICULTURAL OUTPUT IN SYRIA

    Directory of Open Access Journals (Sweden)

    Adel Shakeeb MOHSEN

    2016-04-01

    Full Text Available This study investigates the determinants of agricultural output in Syria, 1980-2010. The Johansen cointegration test results indicate that agricultural outputs are positively related to the capital, food exports, expenditure and arable land, and negatively related to the oil price. Arable land has the biggest effect on agricultural outputs. The Granger causality test indicates bidirectional short-run causality relationships between capital, food exports, expenditure, arable land and agricultural outputs, and unidirectional short-run causality relationship running from oil price to agricultural outputs. There are also unidirectional long-run causality relationships moving from agricultural outputs to gross fixed capital formation of agriculture, oil price, food exports and arable land. However, there is no long-run causality relationships between final consumption expenditure and agricultural outputs. The result indicates that it is important to speed up the land reclamation process and encourage the investment in the agricultural sector.

  2. Thyroid Hormone Control of Cardiac Substrate Metabolism

    OpenAIRE

    Hyyti Villet, Outi

    2009-01-01

    Thyroid hormone (TH) plays an important role in maintaining a homeostasis in all the cells of our body. It also has significant cardiovascular effects, and abnormalities of its concentration can cause cardiovascular disease and even morbidity. Especially development of heart failure has been connected to low levels of thyroid hormone. A decrease in TH levels or TH-receptor binding adversely effects cardiac function. Although, this occurs in part through alterations in excitation-contraction a...

  3. Cardiac Rehabilitation in Patients with Heart Failure

    OpenAIRE

    Fu, Tieh-Cheng; Huang, Shu-Chun; Hsu, Chih-Chin; Wang, Chao-Hung; Wang, Jong-Shyan

    2014-01-01

    Reduced exercise capacity negatively affects the ability of patients with heart failure (HF) to perform activities required for daily life, further decreasing their independence and quality of life (QoL). Cardiac rehabilitation (CR) can effectively improve aerobic fitness and overall health status in patients with HF. Low referral rate is an important limitation that may impede successful CR, whereas the automatic referral and liaison strategies performed by some healthcare providers manifest...

  4. Cardiac metastases of osteosarcoma

    International Nuclear Information System (INIS)

    Osteosarcoma is a malignancy whose various sites of metastasis greatly modify its ultimate prognosis. We report a case of simultaneous pulmonary and cardiac metastases in a 41-year-old male patient with osteosarcoma of the tibia, presenting after more then one year of completion of adjuvant therapy with progressive dyspnea and cyanosis. Diagnosis was made on computerized tomogram and echocardiogram. The metastatic mass entirely occupying the right ventricle and the pulmonary artery proved fatal. (author)

  5. Cardiac Tissue Engineering

    OpenAIRE

    MILICA RADISIC; GORDANA VUNJAK-NOVAKOVIC

    2009-01-01

    We hypothesized that clinically sized (1-5 mm thick),compact cardiac constructs containing physiologically high density of viable cells (~108 cells/cm3) can be engineered in vitro by using biomimetic culture systems capable of providing oxygen transport and electrical stimulation, designed to mimic those in native heart. This hypothesis was tested by culturing rat heart cells on polymer scaffolds, either with perfusion of culture medium (physiologic interstitial velocity, supplementation of p...

  6. Cardiac developmental toxicity

    OpenAIRE

    Mahler, Gretchen J.; Jonathan T Butcher

    2011-01-01

    Congenital heart disease is a highly prevalent problem with mostly unknown origins. Many cases of CHD likely involve an environmental exposure coupled with genetic susceptibility, but practical and ethical considerations make nongenetic causes of CHD difficult to assess in humans. The development of the heart is highly conserved across all vertebrate species, making animal models an excellent option for screening potential cardiac teratogens. This review will discuss exposures known to cause ...

  7. Penetrating Cardiac Injuries

    OpenAIRE

    ÖZYAZICIOĞLU, Ahmet

    2002-01-01

    Objectives: To present our experience of penetrating cardiac injuries treated at Atatürk University hospital; in 17 years 38 patients were analyzed. Methods: Patients were classified into three groups: group A (stable), 12; group B (shock), 21; and group C (agonal), five. Five patients were treated by pericardial window and three by pericardiocentesis. Two patients in group C, 19 patients in group B and five patients in group A underwent median sternotomy or thoracotomy in the operating room...

  8. Benign cardiac tumours: cardiac CT and MRI imaging appearances

    International Nuclear Information System (INIS)

    Full text: Primary benign cardiac tumours are rarely found in clinical practice and are generally evaluated with echocardiography. However, with the increasing usage of helical multislice CT, the initial detection and evaluation of these masses may be made by the radiologist during routine daily practice for other indications. The echocardiographic, CT and cardiac MRI appearances of various benign cardiac tumours and masses are described and illustrated in this review

  9. Cardiac tissue engineering

    Directory of Open Access Journals (Sweden)

    MILICA RADISIC

    2005-03-01

    Full Text Available We hypothesized that clinically sized (1-5 mm thick,compact cardiac constructs containing physiologically high density of viable cells (~108 cells/cm3 can be engineered in vitro by using biomimetic culture systems capable of providing oxygen transport and electrical stimulation, designed to mimic those in native heart. This hypothesis was tested by culturing rat heart cells on polymer scaffolds, either with perfusion of culture medium (physiologic interstitial velocity, supplementation of perfluorocarbons, or with electrical stimulation (continuous application of biphasic pulses, 2 ms, 5 V, 1 Hz. Tissue constructs cultured without perfusion or electrical stimulation served as controls. Medium perfusion and addition of perfluorocarbons resulted in compact, thick constructs containing physiologic density of viable, electromechanically coupled cells, in contrast to control constructs which had only a ~100 mm thick peripheral region with functionally connected cells. Electrical stimulation of cultured constructs resulted in markedly improved contractile properties, increased amounts of cardiac proteins, and remarkably well developed ultrastructure (similar to that of native heart as compared to non-stimulated controls. We discuss here the state of the art of cardiac tissue engineering, in light of the biomimetic approach that reproduces in vitro some of the conditions present during normal tissue development.

  10. Bank output measurement in the euro area : A modified approach

    NARCIS (Netherlands)

    Colangelo, A.; Inklaar, R.

    2012-01-01

    Banks do not charge explicit fees for many of the services they provide, bundling the service payment with the offered interest rates. This output therefore has to be imputed using estimates of the opportunity cost of funds. We argue that rather than using the single short-term, low-risk interest ra

  11. Visual display panel functions as computer input/output device

    Science.gov (United States)

    Hilborn, E. H.

    1970-01-01

    Display panel permits information entry and erasure using a probe, and has an inherent storage capability for use on time-shared systems. Data input need not be online. Other advantages include direct display of input and output, simplicity, and low fabrication cost.

  12. Incretin attenuates diabetes-induced damage in rat cardiac tissue.

    Science.gov (United States)

    AbdElmonem Elbassuoni, Eman

    2014-09-01

    Glucagon-like peptide-1 (GLP-1), as a member of the incretin family, has a role in glucose homeostasis, its receptors distributed throughout the body, including the heart. The aim was to investigate cardiac lesions following diabetes induction, and the potential effect of GLP-1 on this type of lesions and the molecular mechanism driving this activity. Adult male rats were classified into: normal, diabetic, 4-week high-dose exenatide-treated diabetic rats, 4-week low-dose exenatide-treated diabetic rats, and 1-week exenatide-treated diabetic rats. The following parameters were measured: in blood: glucose, insulin, lactate dehydrogenase (LDH), total creatine kinase (CK), creatine kinase MB isoenzyme (CK-MB), and CK-MB relative index; in cardiac tissue: lipid peroxide (LPO) and some antioxidant enzymes. The untreated diabetic group displayed significant increases in blood level of glucose, LDH, and CK-MB, and cardiac tissue LPO, and a significant decrease in cardiac tissue antioxidant enzymes. GLP-1 supplementation in diabetic rats definitely decreased the hyperglycemia and abolished the detrimental effects of diabetes on the cardiac tissue. The effect of GLP-1 on blood glucose and on the heart also appeared after a short supplementation period (1 week). It can be concluded that GLP-1 has beneficial effects on diabetes-induced oxidative cardiac tissue damage, most probably via its antioxidant effect directly acting on cardiac tissue and independent of its hypoglycemic effect. PMID:25011640

  13. PREVIMER : Meteorological inputs and outputs

    Science.gov (United States)

    Ravenel, H.; Lecornu, F.; Kerléguer, L.

    2009-09-01

    PREVIMER is a pre-operational system aiming to provide a wide range of users, from private individuals to professionals, with short-term forecasts about the coastal environment along the French coastlines bordering the English Channel, the Atlantic Ocean, and the Mediterranean Sea. Observation data and digital modelling tools first provide 48-hour (probably 96-hour by summer 2009) forecasts of sea states, currents, sea water levels and temperatures. The follow-up of an increasing number of biological parameters will, in time, complete this overview of coastal environment. Working in partnership with the French Naval Hydrographic and Oceanographic Service (Service Hydrographique et Océanographique de la Marine, SHOM), the French National Weather Service (Météo-France), the French public science and technology research institute (Institut de Recherche pour le Développement, IRD), the European Institute of Marine Studies (Institut Universitaire Européen de la Mer, IUEM) and many others, IFREMER (the French public institute fo marine research) is supplying the technologies needed to ensure this pertinent information, available daily on Internet at http://www.previmer.org, and stored at the Operational Coastal Oceanographic Data Centre. Since 2006, PREVIMER publishes the results of demonstrators assigned to limited geographic areas and to specific applications. This system remains experimental. The following topics are covered : Hydrodynamic circulation, sea states, follow-up of passive tracers, conservative or non-conservative (specifically of microbiological origin), biogeochemical state, primary production. Lastly, PREVIMER provides researchers and R&D departments with modelling tools and access to the database, in which the observation data and the modelling results are stored, to undertake environmental studies on new sites. The communication will focus on meteorological inputs to and outputs from PREVIMER. It will draw the lessons from almost 3 years during

  14. Indeterminacy of Spatiotemporal Cardiac Alternans

    CERN Document Server

    Zhao, Xiaopeng

    2007-01-01

    Cardiac alternans, a beat-to-beat alternation in action potential duration (at the cellular level) or in ECG morphology (at the whole heart level), is a marker of ventricular fibrillation, a fatal heart rhythm that kills hundreds of thousands of people in the US each year. Investigating cardiac alternans may lead to a better understanding of the mechanisms of cardiac arrhythmias and eventually better algorithms for the prediction and prevention of such dreadful diseases. In paced cardiac tissue, alternans develops under increasingly shorter pacing period. Existing experimental and theoretical studies adopt the assumption that alternans in homogeneous cardiac tissue is exclusively determined by the pacing period. In contrast, we find that, when calcium-driven alternans develops in cardiac fibers, it may take different spatiotemporal patterns depending on the pacing history. Because there coexist multiple alternans solutions for a given pacing period, the alternans pattern on a fiber becomes unpredictable. Usin...

  15. Biosynthesis of cardiac natriuretic peptides

    DEFF Research Database (Denmark)

    Goetze, Jens Peter

    2010-01-01

    Cardiac-derived peptide hormones were identified more than 25 years ago. An astonishing amount of clinical studies have established cardiac natriuretic peptides and their molecular precursors as useful markers of heart disease. In contrast to the clinical applications, the biogenesis of cardiac p...... competent endocrine cells. The structurally related atrial natriuretic peptide will be mentioned where appropriate, whereas C-type natriuretic peptide will not be considered as a cardiac peptide of relevance in mammalian physiology....... characterized. An ongoing characterization of the molecular heterogeneity will help appreciate the biosynthetic capacity of the endocrine heart and could introduce new diagnostic possibilities. Notably, different biosynthetic products may not be equal markers of the same pathophysiological processes. An...... inefficient post-translational prohormone maturation will also affect the biology of the cardiac natriuretic peptide system. This review aims at summarizing the myocardial synthesis of natriuretic peptides focusing on B-type natriuretic peptide, where new data has disclosed cardiac myocytes as highly...

  16. Biosynthesis of cardiac natriuretic peptides

    DEFF Research Database (Denmark)

    Goetze, Jens Peter

    2010-01-01

    Cardiac-derived peptide hormones were identified more than 25 years ago. An astonishing amount of clinical studies have established cardiac natriuretic peptides and their molecular precursors as useful markers of heart disease. In contrast to the clinical applications, the biogenesis of cardiac...... inefficient post-translational prohormone maturation will also affect the biology of the cardiac natriuretic peptide system. This review aims at summarizing the myocardial synthesis of natriuretic peptides focusing on B-type natriuretic peptide, where new data has disclosed cardiac myocytes as highly...... competent endocrine cells. The structurally related atrial natriuretic peptide will be mentioned where appropriate, whereas C-type natriuretic peptide will not be considered as a cardiac peptide of relevance in mammalian physiology....

  17. An overview of cardiac morphogenesis.

    Science.gov (United States)

    Schleich, Jean-Marc; Abdulla, Tariq; Summers, Ron; Houyel, Lucile

    2013-11-01

    Accurate knowledge of normal cardiac development is essential for properly understanding the morphogenesis of congenital cardiac malformations that represent the most common congenital anomaly in newborns. The heart is the first organ to function during embryonic development and is fully formed at 8 weeks of gestation. Recent studies stemming from molecular genetics have allowed specification of the role of cellular precursors in the field of heart development. In this article we review the different steps of heart development, focusing on the processes of alignment and septation. We also show, as often as possible, the links between abnormalities of cardiac development and the main congenital heart defects. The development of animal models has permitted the unraveling of many mechanisms that potentially lead to cardiac malformations. A next step towards a better knowledge of cardiac development could be multiscale cardiac modelling. PMID:24138816

  18. The current cardiac safety situation with antihistamines.

    Science.gov (United States)

    Yap, Y G; Camm, A J

    1999-03-01

    Antihistamines (H1-receptor antagonists) are amongst the most frequently prescribed drugs worldwide for the treatment of allergic conditions. The clinical interest of classical 'first generation' antihistamines is currently rather limited by their anticholinergic and sedative properties. The second generation of antihistamines, so-called non-sedating antihistamines, are free of these side-effects. However, since the 1990s, there have been reports that certain non-sedating antihistamines, mainly terfenadine and astemizole, might be associated with the risk of rare but severe dysrhythmias. These drugs prolong the monophasic action potential and surface electrocardiographic QT interval and may lead to the development of early after-depolarization and possibly torsades de pointes through an inhibition of potassium channel repolarization. Concomitant administration with drugs that inhibit the hepatic cytochrome P-450 (imidazole antifungals, macrolide antibiotics) or those that prolong the QT interval by the same or other mechanism (e.g. antiarrhythmics, antipsychotics, tricyclic antidepressants) increases their effect on the cardiac repolarization. The cardiac safety profile of newer non-sedating antihistamines requires confirmation. Drugs with low or no potential to block the K + rectification channel (e.g. IKr channels) are likely to possess cardiac safety advantages. Other drug-related factors such as the physico-chemical properties of the antihistamines and its metabolic profile may also contribute to the cardiac response. Mizolastine is a new non-sedating antihistamine with antiallergic properties. It has a good bioavailability and a metabolism via the cytochrome P-450 oxidation accounting for only 35% of its hepatic clearance. In addition, mizolastine displays low lipophilicity and consequently low cardiac tissue fixation. In clinical studies, mizolastine has not shown any dose-related increase in QT intervals. Its clinical use has not been associated with

  19. Relationship between Multi-Output Partially Bent Functions and Multi-Output Bent Functions

    Institute of Scientific and Technical Information of China (English)

    ZHAO Yaqun; JU Guizhi; WANG Jue

    2006-01-01

    In this paper, the definition of multi-output partially Bent functions is presented and some properties are discussed. Then the relationship between multi-output partially Bent functions and multi-output Bent functions is given in Theorem 4, which includes Walsh spectrum expression and function expression. This shows that multi-output partially Bent functions and multi-output Bent functions can define each other in principle. So we obtain the general method to construct multi-output partially Bent functions from multi-output Bent functions.

  20. Cardiac catheterization and complications: initial experience

    Directory of Open Access Journals (Sweden)

    L Dubey

    2012-09-01

    Full Text Available Cardiac catheterization for diagnostic and therapeutic purposes has been routinely used since last one year in College of Medical Sciences and Teaching Hospital, Bharatpur, Nepal. Because all cardiac catheterizations involve the insertion of cardiac catheters into the circulatory system, it should not be surprising that a variety of complications can ensue. These complications range from minor problems with no long-term sequelae to major problem even death. A total of 357 consecutive diagnostic and therapeutic cardiac catheterization performed in College of Medical Sciences and Teaching Hospital, Bharatpur between April 2011 to April 2012 were evaluated for their complications. Among them 220 (61.6% were coronary angiogram, 65 (18.2 % percutaneous transluminal coronary angioplasty (PTCA and stenting, 7 ( 1.9 % permanent pacemaker insertion, 65 (18.2% were others including temporary pacemaker insertion, peripheral angiography and carotid angiography. There were 3 deaths (0.84%. Two deaths occurred following coronary angiogram and 1 death following PTCA stenting. Vascular complications occurred in 5 (1.4% patients with groin haematoma in all. Contrast allergy occurred in 9 (2.5 %, vasovagal reaction in 2 (0.56%, pyrogen reaction in 6 (1.6%, and contrast induced nephropathy occurred in 3 (0.84% patients. Cardiac catheterization procedure in CMS-TH, Bharatpur has acceptable low complications including death. Journal of College of Medical Sciences-Nepal,2012,Vol-8,No-2, 1-6 DOI: http://dx.doi.org/10.3126/jcmsn.v8i2.6830