Sample records for cardiac output assessment

  1. Assessment of cardiac output by the Doppler ultrasound technique alone

    Microsoft Academic Search

    N E Haites; F M McLennan; D H Mowat; J M Rawles

    1985-01-01

    The normal range of aortic blood velocity was established in 140 healthy adults, using a non-invasive Doppler ultrasound technique. Integration of the area under the velocity-time curve for each heart beat gave stroke distance, which, when multiplied by heart rate, gave minute distance. Stroke distance and minute distance are an indication of stroke volume and cardiac output respectively and both

  2. Cardiac output monitoring by pressure recording analytical method in cardiac surgery

    Microsoft Academic Search

    Pierpaolo Giomarelli; Bonizella Biagioli; Sabino Scolletta

    2004-01-01

    Objective: A less-invasive method has been developed that may provide an alternative to monitor cardiac output from arterial pressure: beat-to-beat values of cardiac output can be obtained by pressure recording analytical method (PRAM). The purpose of this study was to assess the reliability of cardiac output determination by PRAM in cardiac surgery. Methods: Cardiac output was measured in 28 patients

  3. Cardiac output monitoring by pressure recording analytical method in cardiac surgery

    Microsoft Academic Search

    Pierpaolo Giomarelli; Bonizella Biagioli; Sabino Scolletta; Viale Bracci

    2010-01-01

    Objective: A less-invasive method has been developed that may provide an alternative to monitor cardiac output from arterial pressure: beat-to-beat values of cardiac output can be obtained by pressure recording analytical method (PRAM). The purpose of this study was to assess the reliability of cardiac output determination by PRAM in cardiac surgery. Methods: Cardiac output was measured in 28 patients

  4. Cardiac output measurement in children: comparison of the Ultrasound Cardiac Output Monitor with thermodilution cardiac output measurement

    Microsoft Academic Search

    Walter Knirsch; Oliver Kretschmar; Maren Tomaske; Kathrina Stutz; Nicole Nagdyman; Christian Balmer; Achim Schmitz; Dominique Béttex; Felix Berger; Urs Bauersfeld; Markus Weiss

    2008-01-01

    Objective  To compare the assessment of cardiac output (CO) in children using the noninvasive Ultrasound Cardiac Output Monitor (USCOM)\\u000a with the invasive pulmonary artery catheter (PAC) thermodilution cardiac output measurement.\\u000a \\u000a \\u000a \\u000a Design and setting  Prospective observational study in a tertiary center for pediatric cardiology of a university children's hospital.\\u000a \\u000a \\u000a \\u000a Patients  Twenty-four pediatric patients with congenital heart disease without shunt undergoing cardiac catheterization under general\\u000a anesthesia.\\u000a \\u000a \\u000a \\u000a Measurements

  5. A pilot assessment of the FloTrac TM cardiac output monitoring system

    Microsoft Academic Search

    Helen Ingrid Opdam; Li Wan; Rinaldo Bellomo

    2007-01-01

    Objective  To compare measurement of cardiac output (CO) by means of the FloTracTM CO monitor with the pulmonary artery catheter (PAC).\\u000a \\u000a \\u000a \\u000a Design  Prospective observational study.\\u000a \\u000a \\u000a \\u000a Setting  Intensive care unit of a tertiary hospital.\\u000a \\u000a \\u000a \\u000a Patients  Six post-operative cardiac surgery patients with existing arterial cannulas and PACs.\\u000a \\u000a \\u000a \\u000a Interventions  Attachment of the FloTracTM CO monitor and transducer to an existing arterial cannula. Simultaneous measurements of CO, indexed to body

  6. Cardiac output monitoring devices: an analytic review.

    PubMed

    Porhomayon, Jahan; El-Solh, Ali; Papadakos, Peter; Nader, Nader Djalal

    2012-04-01

    To evaluate cardiac output (CO), both invasive and semi-invasive monitors are used in critical care medicine. The pulmonary artery catheter is an invasive tool to assess CO with the major criticism that the level of its invasiveness is not supported by an improvement in patients' outcomes. The interest in a lesser invasive techniques is high. Therefore, alternative techniques have been developed recently, and are used frequently in critical care medicine. Cardiac output can be monitored continuously by different devices that analyze the stroke volume and CO. The purpose of this review is to understand these new technologies and their applications and limitations. PMID:22147648

  7. Mathematics and the Heart: Understanding Cardiac Output

    ERIC Educational Resources Information Center

    Champanerkar, Jyoti

    2013-01-01

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

  8. Cardiac output monitoring in horses.

    PubMed

    Shih, Andre

    2013-04-01

    Cardiac output (CO) is the volume of blood pumped out by the heart in 1 minute. Monitoring of CO can guide therapy and improve clinical outcome in critically ill patients and during anesthesia. Although there is increasing research into clinically useful methods of monitoring CO in equine patients, there are limitations to the available methods. There are 4 basic methods of measuring CO: (1) indicator methods, (2) a derivation of the Fick principle, (3) arterial pulse wave analysis, and (4) imaging diagnostic techniques. This article discusses the importance of CO, available technology, and challenges of monitoring CO in equine medicine. PMID:23498050

  9. Assessment of Stroke Volume Variation Perioperatively by Using Arterial Pressure with Cardiac Output.

    PubMed

    Li, Wen-Jing; Hu, Yi-Ping; Zhu, Min-Min

    2015-07-01

    Objective To observe the sensitivity of stroke volume variation (SVV) for assessing volume change during induction period of general anesthesia.Methods Patients who underwent orthopaedic surgery under general anesthesia and mechanical ventilation were divided into two groups randomly. Patients in the group ?were subjected to progressive central hypovolemia and correction of hypovolemia sequentially; patients in the Group ? were exposed to hypervolemia alone. Each step was implemented after 5 minutes when the hemodynamics was stable. SVV and cardiac index (CI) were recorded, and Pearson's product-moment correlation was used to analyze correlation between SVV and CI.Results Forty patients were included in this study, 20 cases in each group. For group ? patients, SVV was increased significantly along with blood volume reduction, and changes in CI were negatively correlated with changes in SVV (r=-0.605, P<0.01); SVV decreased significantly along with correction of blood volume; changes in CI were negatively correlated with changes in SVV (r=-0.651, P<0.01). For group ? patients, along with blood volume increase, SVV did not change significantly; changes in CI revealed no significant correlation with changes in SVV (r=0.067, P>0.05).Conclusion SVV is a useful indicator for hypovolemia, but not for hypervolemia. PMID:26149000

  10. Bioimpedance and bioreactance methods for monitoring cardiac output.

    PubMed

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

    2014-12-01

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

  11. Assessment of left ventricular cardiac output by arterial thermodilution technique via a left atrial catheter in a patient on a right ventricular assist device.

    PubMed

    Wiesenack, Christoph; Prasser, Christopher; Liebold, Andreas; Schmid, Franz X

    2004-01-01

    Following heart transplantation (HTx) in a 49-year old male, the patient's haemodynamic situation deteriorated in the early postoperative period despite increasing doses of catecholamines. When transoesophageal echocardiography (TEE) showed a dilated right ventricle, but adequate left ventricular (LV) function, a right ventricular assist device (RVAD) was implanted to support the right ventricle of the failing graft. Evaluation of the resulting cardiac output (CO) of the left ventricle and, thus, assessment of the remaining right ventricular function in patients supported by a RVAD is of great clinical interest. In this situation, continuous measurement of LV function, enabling assessment of the remaining right ventricular function, can be performed by pulse contour analysis following initial calibration of the system by arterial thermodilution CO measurement via a left atrial catheter. PMID:15072259

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

    PubMed Central

    Perrino, A. C.

    1993-01-01

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

  13. Cardiac output assessed by non-invasive monitoring is associated with ECG changes in children with critical asthma.

    PubMed

    Wong, Jackson; Dorney, Kate; Hannon, Megan; Steil, Garry M

    2014-02-01

    The primary aim of this study was to determine changes in CI and SI, if any, in children hospitalized with status asthmatics during the course of treatment as measured by non-invasive EC monitoring. The secondary aim was to determine if there is an association between Abnormal CI (defined as <5 or >95 % tile adjusted for age) and Abnormal ECG (defined as ST waves changes) Non-invasive cardiac output (CO) recordings were obtained daily from admission (Initial) to discharge (Final). Changes in CI and SI measurements were compared using paired t tests or 1-way ANOVA. The association between Abnormal CI on Initial CO recording and Abnormal ECG was analyzed by Fischer's exact test. Data are presented as mean ± SEM with mean differences reported with 95 % confidence interval; p < 0.05 was considered significant. Thirty-five children with critical asthma were analyzed. CI decreased from 6.2 ± 0.2 to 4.5 ± 0.1 [-1.6 (-0.04 to -0.37)] L/min/m(2) during hospitalization. There was no change in SI. There was a significant association between Abnormal Initial CI and Abnormal ECG (p = 0.02). In 11 children requiring prolonged hospitalization CI significantly decreased from 7.2 ± 0.5 to 4.0 ± 0.2 [-3.2 (-4.0 to -2.3)] L/min/m(2) and SI decreased from 51.2 ± 3.8 to 40.3 ± 2.0 [-11.0 (-17.6 to -4.4)] ml/beat/m(2) There was a significant decrease in CI in all children treated for critical asthma. In children that required a prolonged course of treatment, there was also a significant decrease in SI. Abnormal CI at Initial CO recording was associated with ST waves changes on ECG during hospitalization. Future studies are required to determine whether non-invasive CO monitoring can predict which patients are at risk for developing abnormal ECG. PMID:23873137

  14. Rapid cardiac-output measurement with ungated spiral phase contrast

    Microsoft Academic Search

    Jong B. Park; Bob S. Hu; Steven M. Conolly; Krishna S. Nayak; Dwight G. Nishimura

    2006-01-01

    An ungated spiral phase-contrast (USPC) method was used to measure cardiac output (CO) rapidly and conveniently. The USPC method, which was originally designed for small periph- eral vessels, was modified to assess CO by measuring flow in the ascending aorta (AA). The modified USPC used a 12-inter- leaf spiral trajectory to acquire full-image data every 283 ms with 2-mm spatial

  15. Cardiac output monitoring: basic science and clinical application: Cardiac output monitoring

    Microsoft Academic Search

    S. Jhanji; J. Dawson; R. M. Pearse

    2008-01-01

    Summary Derangements in the circulation are a common feature of sepsis, trauma, major surgery and other critical illnesses. Detailed evaluation of the circulation is therefore an essential aspect of the clinical management of such patients. The use of cardiac output monitoring technology is an increasingly important aspect of evaluating patients in the operating theatre, critical care unit and elsewhere. There

  16. Newer methods of cardiac output monitoring.

    PubMed

    Mehta, Yatin; Arora, Dheeraj

    2014-09-26

    Cardiac output (CO) is the volume of blood ejected by each ventricle per minute and is the product of stroke volume and heart rate. CO can thus be manipulated by alteration in heart rate or rhythm, preload, contractility and afterload. Moreover it gives important information about tissue perfusion and oxygen delivery. CO can be measured by various methods and thermodilution method using pulmonary artery catheter (PAC) is till date considered as gold standard method. Complications associated with PAC led to development of newer methods which are minimally or non-invasive. Newer methods fulfil other properties like continuous and reproducible reading, cost effective, reliable during various physiological states and have fast response time. These methods are validated against the gold standard with good level agreement. In this review we have discussed various newer methods of CO monitoring and their effectiveness in clinical use. PMID:25276302

  17. Cardiac output and stroke volume estimation using a hybrid of three models

    E-print Network

    Arai, Tatsuya

    Cardiac output (CO) and stroke volume (SV) are the key hemodynamic parameters to be monitored and assessed in ambulatory and critically ill patients. The purpose of this study was to introduce and validate a new algorithm ...

  18. Predictors of low cardiac output syndrome after coronary artery bypass

    Microsoft Academic Search

    Vivek Rao; Joan Ivanov; Richard D. Weisel; John S. Ikonomidis; George T. Christakis; Tirone E. David

    1996-01-01

    The purpose of this study was to identify patients at risk for the development of low cardiac output syndrome after coronary artery bypass. Low cardiac output syndrome was defined as the need for postoperative intraaortic balloon pump or inotropic support for longer than 30 minutes in the intensive care unit to maintain the systolic blood pressure greater than 90 mm

  19. Impedance cardiography for monitoring changes in cardiac output.

    PubMed

    Parashar, Rachna; Bajpai, Manish; Goyal, Manish; Singh, Shraddha; Tiwari, Sunita; Narayan, V S

    2012-01-01

    Impedance Cardiography (ICG) is a non invasive method useful for continuous monitoring of cardiac output but, it still has not found wide usage for measuring cardiac output in clinics and research. Most studies focused on comparing the cardiac output measured at rest with reference methods. In the present study we evaluated the validity of ICG against Doppler Echocardiography (DE) in measuring cardiac output changes that occur during static exercise. Cardiac output of 30 healthy males between 18-26 yrs of age was measured during supine rest, during and 5 min after completion of 3 minute static exercise by ICG and DE. The increase in cardiac output during exercise measured with ICG and DE does not differ significantly (1.04 +/- 0.72 L/min and 1.05 +/- 1.24 L/min respectively) and has significantly high correlation (r = 0.76, P < 0.001). The bias and limits of agreement are (-0.01 +/- 0.83) in acceptable limits. The pooled means of cardiac output measured by ICG and DE do not differ significantly and bears a significant correlation (r = 0.812, P < 0.001). The bias (d +/- s) calculated is 0.15 +/- 0.64 L/min. ICG could provide valid information regarding the relative changes in cardiac output. PMID:23387239

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

    PubMed

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

    2015-04-01

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

  1. [Development of cardiac output monitoring system based on thermodilution method].

    PubMed

    Ye, Jilun; Jiang, Yun; Luo, Sai; Wang, Fan; Zhang, Xu

    2014-09-01

    Cardiac output (CO) monitoring is a crucial part of the hemodynamic status monitoring. So far, thermodilution method, which is clinically recognized as the gold standard method to monitor cardiac output, still has irreplaceable advantages. This paper mainly introduces the use of platform for cardiac output measurement based on thermodilution method, mainly including three parts: the hardware platform, software design and algorithm process. A large amount of test data of this system has been got by CO simulator testing in the laboratory and preliminary clinical tests in the hospital. The testing result showed that using the proposed system can achieve good accuracy and repeatability. PMID:25597080

  2. Cardiac output monitoring: aortic transpulmonary thermodilution and pulse contour analysis agree with standard thermodilution methods in patients undergoing lung transplantation

    Microsoft Academic Search

    Giorgio Della Rocca; Maria Gabriella Costa; Cecilia Coccia; Livia Pompei; Pierangelo Di Marco; Vincenzo Vilardi; Paolo Pietropaoli

    2003-01-01

    Purpose  The PiCCO System is a relatively new device allowing intermittent cardiac output monitoring by aortic transpulmonary thermodilution\\u000a technique (Aorta intermittent) and continuous cardiac output monitoring by pulse contour analysis (Aorta continuous). The\\u000a objective of this study was to assess the level of agreement of Aorta intermittent and Aorta continuous with intermittent\\u000a (PA intermittent) and continuous cardiac output (PA continuous) measured

  3. The cardiac output from blood pressure algorithms trial

    E-print Network

    Sun, James X.

    Objective: The value of different algorithms that estimate cardiac output (CO) by analysis of a peripheral arterial blood pressure (ABP) waveform has not been definitively identified. In this investigation, we developed a ...

  4. The Effect of Signal Quality on Six Cardiac Output Estimators

    E-print Network

    Mark, Roger Greenwood

    The effect of signal quality on the accuracy of cardiac output (CO) estimation from arterial blood pressure (ABP) was evaluated using data from the MIMIC II database. Thermodilution CO (TCO) was the gold standard. A total ...

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

    Microsoft Academic Search

    R. Mukkamala; A. T. Reisner; H. M. Hojman; Roger G. Mark; Richard J. Cohen

    2003-01-01

    We introduce a novel technique for continuously monitoring changes in cardiac output (CO) by mathematical analysis of a single peripheral arterial blood pressure (ABP) waveform. In contrast to all previous techniques, our technique analyzes ABP variations over time scales greater than a cardiac cycle in which wave reflections are attenuated. To validate the technique, we performed six swine experiments in

  6. Testing the safety of baxter continuous cardiac output monitoring system

    Microsoft Academic Search

    Peter R. Lichtenthal; Donovan Gordan

    1996-01-01

    The safety of a new continuous cardiac output monitoring system, recently introduced by Baxter Healthcare Corporation's Edwards\\u000a Critical-Care Division, was evaluated in normal sheep. The study compared the biocompatibility and safety of the Vigilance®\\u000a CCO Monitoring System, which employs a continuous cardiac output (CCO) catheter with Baxter Edwards' standard Paceport™ pulmonary\\u000a artery catheter.\\u000a \\u000a The CCO catheter, which monitors hemodynamic pressures

  7. Feasibility of cardiac output estimation by ultrasonic cardiac output monitoring in the prehospital setting.

    PubMed

    Duchateau, François-Xavier; Gauss, Tobias; Burnod, Alexis; Ricard-Hibon, Agnès; Juvin, Philippe; Mantz, Jean

    2011-12-01

    The possible benefits of ultrasonic cardiac output monitoring (USCOM) in emergency medicine practice could be significant if evaluated in a goal-directed protocol. The aim of this study was to perform a feasibility study in a physician-staffed prehospital emergency medicine system. This study enrolled a convenient sample of 50 patients with circulatory distress. Main criteria were visualization of acceptable curves and obtaining interpretable values. Acceptable curves and interpretable values (main criterion) were obtained for 35 patients (70%). In case of failure, the patient was very often dyspneic (80 vs. 23%, when the technique was successful, P<0.001). Mean duration of USCOM examination was 105 ± 60 s. The acceptable success rate for a new technique we observed and the high easy-to-use score suggests that the use of USCOM is feasible in prehospital emergency medicine. PMID:21572333

  8. Noninvasive cardiac output monitoring (NICOM): a clinical validation

    Microsoft Academic Search

    Pierre Squara; Dominique Denjean; Philippe Estagnasie; Alain Brusset; Jean Claude Dib; Claude Dubois

    2007-01-01

    Objective  To evaluate the clinical utility of a new device for continuous noninvasive cardiac output monitoring (NICOM) based on chest\\u000a bio-reactance compared with cardiac output measured semi-continuously by thermodilution using a pulmonary artery catheter\\u000a (PAC-CCO).\\u000a \\u000a \\u000a \\u000a Design  Prospective, single-center study.\\u000a \\u000a \\u000a \\u000a Setting  Intensive care unit.\\u000a \\u000a \\u000a \\u000a Patients  Consecutive adult patients immediately after cardiac surgery.\\u000a \\u000a \\u000a \\u000a Interventions  Cardiac output measurements obtained from NICOM and thermodilution were simultaneously recorded minute by minute and

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

    PubMed Central

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

    2015-01-01

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

  10. [Various methods for monitoring cardiac output in intensive care patients].

    PubMed

    Palsgaard Møller, Thea; Perner, Anders; Bülow, Hans-Henrik

    2012-09-01

    This article presents a mini medical technology evaluation of three less invasive monitoring techniques for monitoring cardiac output, CardioQ, ECOM and PiCCO, with focus on validation, usability and costs in intensive care. In conclusion, when identifying patients with low cardiac output, we suggest starting with simple screening tools (e.g. CardioQ or central venous O2 saturation), and when in doubt, upgrade to better validated, yet more time-consuming techniques (e.g. PiCCO using thermodilution). Also consults should be made to other intensive care units in terms of the practical implementation of the monitors. PMID:22944325

  11. Pulse Contour Analysis for Cardiac Output Monitoring in Cardiac Surgery for Congenital Heart Disease

    Microsoft Academic Search

    Aman Mahajan; Afshin Shabanie; Judi Turner; Michael J. Sopher; Jure Marijic

    2003-01-01

    Conventional methods of cardiac output monitoring usingpulmonaryarterycathetersmaynotbefeasiblein patients with congenital heart disease because of pa- tients' small size or aberrant anatomy. We studied the accuracy of a new device, which uses pulse contour analysis to measure continuous cardiac output, in chil- dren and adults undergoing congenital heart surgery. Sixteenpatients,medianages7yrold,wereincludedin this prospective study. One-hundred-ninety-one data points were obtained in the pre-

  12. Hemodynamics of conscious unrestrained baboons, including cardiac output.

    PubMed

    Maclean, J M; Phippard, A F; Thompson, J F; Gillin, A G; Horvath, J S; Duggin, G G; Tiller, D J

    1990-06-01

    A method is described for comprehensive hemodynamic study of undisturbed baboons (Papio hamadryas) that incorporates cardiac output measurement by thermodilution. Instrumentation includes arterial, aortic, and central venous catheterization by a surgical technique that does not require entry to peritoneal or thoracic cavities. It provides a means for right atrial indicator delivery with aortic temperature recording of thermodilution curves. Accuracy was confirmed by comparison to measurement by Swan-Ganz catheters. Diurnal variations of systemic arterial pressure in long-term study of conscious baboons were shown to result from significant increases in cardiac output by day (P less than 0.001), despite concomitant falls in systemic vascular resistance. The cardiac output values obtained were 0.13 l.min-1.kg-1 at night and 0.16 l.min-1.kg-1 by day. Comparison of these results to previous reports of cardiac output in baboons highlights the inadequacies of methods that require physical restraint or anesthesia. This technique also leaves the baboons intact for subsequent breeding or experimental use after catheter removal without the need for further surgery. PMID:2384419

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

    Microsoft Academic Search

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

    2006-01-01

    A clinical method for monitoring cardiac output (CO) should be continuous, minimally invasive, and accurate. However, none of the conventional CO measurement methods possess all of these characteristics. On the other hand, peripheral arterial blood pressure (ABP) may be measured reliably and continuously with little or no invasiveness. We have developed a novel technique for continuously monitoring changes in CO

  14. Feasibility of preclinical cardiac output and systemic vascular resistance in HEMS in thoracic pain—the ultrasonic cardiac output monitor

    Microsoft Academic Search

    K. Knobloch; V. Hubrich; P. Rohmann; M. Lupkemann; T. Gerich; C. Krettek; R. Phillips

    2006-01-01

    BackgroundCardiac output (CO) and systemic vascular resistance (SVR) are important hemodynamic parameters in emergency patients and for clinical early goal-directed therapy. This study evaluated the feasibility of CO and SVR determination using preclinical continuous wave Doppler ultrasound in a helicopter emergency medical service (HEMS) on emergency patients presenting with or without thoracic pain as a pilot observational study.

  15. Applications of minimally invasive cardiac output monitors

    PubMed Central

    2012-01-01

    Because of the increasing age of the population, critical care and emergency medicine physicians have seen an increased number of critically ill patients over the last decade. Moreover, the trend of hospital closures in the United States t imposes a burden of increased efficiency. Hence, the identification of devices that facilitate accurate but rapid assessments of hemodynamic parameters without the added burden of invasiveness becomes tantamount. The purpose of this review is to understand the applications and limitations of these new technologies. PMID:22531454

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

    SciTech Connect

    Yee, Seonghwan, E-mail: Seonghwan.Yee@Beaumont.edu [Department of Radiation Oncology, Beaumont Health System, Royal Oak, Michigan 48073 (United States)] [Department of Radiation Oncology, Beaumont Health System, Royal Oak, Michigan 48073 (United States); Scalzetti, Ernest M. [Department of Radiology, SUNY Upstate Medical University, Syracuse, New York 13210 (United States)] [Department of Radiology, SUNY Upstate Medical University, Syracuse, New York 13210 (United States)

    2014-06-15

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

  17. Response Time of the Opti-Q Continuous Cardiac Output Pulmonary Artery Catheter in the Urgent Mode to a Step Change in Cardiac Output

    Microsoft Academic Search

    Lawrence J. Goldstein

    1999-01-01

    Objectives.This study was conducted to determine the response timeof the Opti-Q continuous cardiac output (CCO) device to a step change incardiac. Design.Prospective study. Setting.University hospitalanimal lab. Model.Female sheep. Interventions.In ten animals,cardiac output was altered suddenly by opening and closing a peripheralarteriovenous shunt to test the response time of the CCO system.Measurements and main results.Cardiac output was measured continuouslyby thermodilution and

  18. Clinical evaluation of USCOM ultrasonic cardiac output monitor in cardiac surgical patients in intensive care unit

    Microsoft Academic Search

    H. L. Tan; M. Pinder; R. Parsons; B. Roberts; P. V. van Heerden

    2005-01-01

    Methods. We conducted a prospective study in the 18-bed intensive care unit of a 600-bed tertiary referral hospital. Twenty-four mechanically ventilated patients were studied immediately following cardiac surgery. We evaluated the USCOM monitor by comparing its output with paired measurements obtained by the standard thermodilution technique using a pulmonary artery catheter. Results. Forty paired measurements were obtained in 22 patients.

  19. [New aspects of minimally invasive cardiac output monitoring].

    PubMed

    Hofer, Christoph K; Schmid, Ursina; Zollinger, Andreas

    2012-02-01

    The variety of minimally invasive cardiac output (CO) monitoring devices is growing rendering it difficult to keep track of new developments. In this article technical principles, limitations and validation procedures considering new aspects are reviewed. An integrated approach for their use is proposed since no single device can comply with all clinical needs. CO should be interpreted in combination with clinical information and other hemodynamic parameters. It's evident that not the monitor per se, but only the protocol / therapy based on the hemodynamic data can improve patients outcome. PMID:22402849

  20. Partial CO2 Rebreathing Indirect Fick Technique for Non-Invasive Measurement of Cardiac Output

    Microsoft Academic Search

    Dinesh G. Haryadi; Joseph A. Orr; Kai Kuck; Scott McJames; Dwayne R. Westenskow

    2000-01-01

    Objective.Evaluation in animals of a non-invasive and continuous cardiac output monitoring system based on partial carbon-dioxide (CO2) rebreathing indirect Fick technique. Methods.We have developed a non-invasive cardiac output (NICO) monitoring system, based on the partial rebreathing method. The partial\\u000a rebreathing technique employs a differential form of the Fick equation for calculating cardiac output (QT) using non-invasive measurements. Changes in CO2

  1. Physiologic and Clinical Principles behind Noninvasive Resuscitation Techniques and Cardiac Output Monitoring

    PubMed Central

    Napoli, Anthony M.

    2012-01-01

    Clinical assessment and vital signs are poor predictors of the overall hemodynamic state. Optimal measurement of the response to fluid resuscitation and hemodynamics has previously required invasive measurement with radial and pulmonary artery catheterization. Newer noninvasive resuscitation technology offers the hope of more accurately and safely monitoring a broader range of critically ill patients while using fewer resources. Fluid responsiveness, the cardiac response to volume loading, represents a dynamic method of improving upon the assessment of preload when compared to static measures like central venous pressure. Multiple new hemodynamic monitors now exist that can noninvasively report cardiac output and oxygen delivery in a continuous manner. Proper assessment of the potential future role of these techniques in resuscitation requires understanding the underlying physiologic and clinical principles, reviewing the most recent literature examining their clinical validity, and evaluating their respective advantages and limitations. PMID:21860802

  2. Physiologic and Clinical Principles behind Noninvasive Resuscitation Techniques and Cardiac Output Monitoring.

    PubMed

    Napoli, Anthony M

    2012-01-01

    Clinical assessment and vital signs are poor predictors of the overall hemodynamic state. Optimal measurement of the response to fluid resuscitation and hemodynamics has previously required invasive measurement with radial and pulmonary artery catheterization. Newer noninvasive resuscitation technology offers the hope of more accurately and safely monitoring a broader range of critically ill patients while using fewer resources. Fluid responsiveness, the cardiac response to volume loading, represents a dynamic method of improving upon the assessment of preload when compared to static measures like central venous pressure. Multiple new hemodynamic monitors now exist that can noninvasively report cardiac output and oxygen delivery in a continuous manner. Proper assessment of the potential future role of these techniques in resuscitation requires understanding the underlying physiologic and clinical principles, reviewing the most recent literature examining their clinical validity, and evaluating their respective advantages and limitations. PMID:21860802

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

    PubMed Central

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

    2014-01-01

    Purpose The 6 minutes walk test (6MWT) is often shown to be the best predictor of mortality in pulmonary hypertension (PH) probably because it challenges the failing heart to deliver adequate cardiac output. We hypothesised that the 6MWT elicits maximal cardiac output as measured during a maximal cardiopulmonary exercise testing (CPET). Methods 18 patients with chronic thromboembolic pulmonary hypertension (n?=?12) or pulmonary arterial hypertension (n?=?6) and 10 healthy subjects performed a 6MWT and CPET with measurements of cardiac output (non invasive rebreathing device) before and directly after exercise. Heart rate was measured during 6MWT with a cardiofrequence meter. Results Cardiac output and heart rate measured at the end of the 6MWT were linearly related to 6MW distance (mean±SD: 490±87 m). Patients with a high NT-pro-BNP achieve a maximum cardiac output during the 6MWT, while in normal subjects and in patients with a low-normal NT-proBNP, cardiac output at the end of a 6MWT was lower than achieved at maximum exercise during a CPET. In both cases, heart rate is the major determinant of exercise-induced increase in cardiac output. However, stroke volume increased during CPET in healthy subjects, not in PH patients. Conclusion Maximal cardiac output is elicited by 6MWT in PH patients with failing right ventricle. Cardiac output increase is dependent on chronotropic response in patients with PH. PMID:24647561

  4. Arterial pressure waveform derived cardiac output FloTrac/Vigileo system (third generation software): comparison of two monitoring sites with the thermodilution cardiac output.

    PubMed

    Vasdev, Sumit; Chauhan, Sandeep; Choudhury, Minati; Hote, Millind P; Malik, Madhur; Kiran, Usha

    2012-04-01

    The present study was conducted to study the effect of monitoring site, radial or femoral, for arterial pressure waveform derived cardiac output using FloTrac/Vigileo system with third generation software version 3.02 during cardiac surgery. The cardiac output derived from the two sites was also compared to the pulmonary artery catheter (PAC) derived cardiac output to reevaluate the relation between them using the newer software. The effect of cardiopulmonary bypass (CPB) was also studied by doing the sub analysis before and after bypass. Forty patients undergoing coronary artery bypass surgery with cardiopulmonary bypass were enrolled in the study. Cardiac output derived from radial artery (RADCO), femoral artery (FEMCO) using FloTrac/Vigileo system with third generation software version 3.02 and cardiac output using pulmonary artery catheter (PACCO) at predefined nine time points were recorded. Three hundred and forty two cardiac output data triplets were analysed. The Bland-Altman analysis of RADCO and FEMCO revealed a mean bias of -0.28 with percentage error of 20%. The pre CPB precision of both RADCO and FEMCO was 1.25 times as that of PACCO. The post CPB precision of FEMCO was 1.2 times of PACCO while that of RADCO was 1.7 times of PACCO. The third generation of FloTrac/Vigileo system shows good correlation between the radial and femoral derived cardiac outputs in both pre and post bypass periods. The newer software correlates better to PAC derived cardiac output in the post bypass period for femoral artery than radial artery. PMID:22350311

  5. Pulse Wave Transit Time Measurements of Cardiac Output in Septic Shock Patients: A Comparison of the Estimated Continuous Cardiac Output System with Transthoracic Echocardiography

    PubMed Central

    Feissel, Marc; Aho, Ludwig Serge; Georgiev, Stefan; Tapponnier, Romain; Badie, Julio; Bruyère, Rémi; Quenot, Jean-Pierre

    2015-01-01

    Background We determined reliability of cardiac output (CO) measured by pulse wave transit time cardiac output system (esCCO system; COesCCO) vs transthoracic echocardiography (COTTE) in mechanically ventilated patients in the early phase of septic shock. A secondary objective was to assess ability of esCCO to detect change in CO after fluid infusion. Methods Mechanically ventilated patients admitted to the ICU, aged >18 years, in sinus rhythm, in the early phase of septic shock were prospectively included. We performed fluid infusion of 500ml of crystalloid solution over 20 minutes and recorded CO by EsCCO and TTE immediately before (T0) and 5 minutes after (T1) fluid administration. Patients were divided into 2 groups (responders and non-responders) according to a threshold of 15% increase in COTTE in response to volume expansion. Results In total, 25 patients were included, average 64±15 years, 15 (60%) were men. Average SAPSII and SOFA scores were 55±21.3 and 13±2, respectively. ICU mortality was 36%. Mean cardiac output at T0 was 5.8±1.35 L/min by esCCO and 5.27±1.17 L/min by COTTE. At T1, respective values were 6.63 ± 1.57 L/min for esCCO and 6.10±1.29 L/min for COTTE. Overall, 12 patients were classified as responders, 13 as non-responders by the reference method. A threshold of 11% increase in COesCCO was found to discriminate responders from non-responders with a sensitivity of 83% (95% CI, 0.52-0.98) and a specificity of 77% (95% CI, 0.46-0.95). Conclusion We show strong correlation esCCO and echocardiography for measuring CO, and change in CO after fluid infusion in ICU patients. PMID:26126112

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

    PubMed

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

    2006-03-01

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

  7. Non-invasive cardiac output and oxygen delivery measurement in an infant with critical anemia

    Microsoft Academic Search

    Garry M. Steil; Olive S. Eckstein; Julie Caplow; Michael S. D. Agus; Brian K. Walsh; Jackson Wong

    2011-01-01

    Objective  To assess the combination of a non-invasive blood oxygen content (CaO2) monitor and a non-invasive cardiac output (CO) monitor to continuously measure oxygen delivery (DO2; DO2 = CaO2 × CO).\\u000a \\u000a \\u000a \\u000a \\u000a Methods  DO2 was assessed during blood transfusions in an infant with acute hemolytic anemia following admission (~48 h). CaO2 was measured by Pulse Co-Oximetry, which also provides estimates of hemoglobin (Hgb) concentration and percent

  8. Continuous cardiac output measurement: pulse contour analysis vs thermodilution technique in cardiac surgical patients.

    PubMed

    Rödig, G; Prasser, C; Keyl, C; Liebold, A; Hobbhahn, J

    1999-04-01

    We have analysed the clinical agreement between two methods of continuous cardiac output measurement pulse contour analysis (PCCO) and a continuous thermodilution technique (CCO), were both compared with the intermittent bolus thermodilution technique (BCO). Measurements were performed in 26 cardiac surgical patients (groups 1 and 2, 13 patients each, with an ejection fraction > 45% and < 45%, respectively) at 12 selected times. During operation, mean differences (bias) between PCCO-BCO and CCO-BCO did not differ in either group. However, phenylephrine-induced increases in systemic vascular resistance (SVR) by approximately 60% resulted in significant differences. Significantly higher absolute bias values of PCCO-BCO compared with CCO-BCO were also found early after operation in the ICU. Thus PCCO and CCO provided comparable measurements during coronary bypass surgery. After marked changes in SVR, further calibration of the PCCO device is necessary. PMID:10472216

  9. Flow-regulated extracorporeal arteriovenous tubing loop for cardiac output measurements by ultrasound velocity dilution: validation in post-cardiac surgery intensive care unit patients.

    PubMed

    Eremenko, Alexsandr A; Safarov, Perviz N

    2010-01-01

    Assessment of cardiac output (CO) is crucial in the management of the critically ill, especially in post cardiac surgery intensive care unit (ICU) patients. In this study, we validated CO measured by the novel ultrasound dilution (COUD) with those measured by pulmonary artery (PA) thermodilution (COTD) in 26 adult post cardiac surgery patients. For COUD, blood was circulated through an extracorporeal arteriovenous (AV) loop from the radial artery catheter to the introducer of PA catheter for 5-8 minutes. Three to four injections of 25 ml body temperature isotonic saline were performed into the venous limb of the AV loop. For COTD, five injections of 10 ml ice cold saline were performed. A total of 77 COUD and COTD measurement sets were compared. Cardiac output measured by thermodilution ranged from 3.28 to 9.4 L/min, whereas COUD ranged from 2.85 to 10.1 L/min. The correlation between the methods was found to be r = 0.91, COUD = 0.93(COTD) + 0.42 L/min. Bias and precision (mean difference ± 2SDs) was -0.004 ± 1.34 L/min between the two methods. The percentage error (2SD/mean) was 22.2%, which is below the clinically acceptable limit (<30%). Cardiac output measured by ultrasound dilution and thermodilution methods agreed well in post cardiac surgery ICU patients and hence can be interchangeably used. PMID:21245798

  10. [Estimating cardiac output. Utility in the clinical practice. Available invasive and non-invasive monitoring].

    PubMed

    García, X; Mateu, L; Maynar, J; Mercadal, J; Ochagavía, A; Ferrandiz, A

    2011-12-01

    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. PMID:21411188

  11. Performance of a minimally invasive uncalibrated cardiac output monitoring system (FlotracTM\\/VigileoTM) in haemodynamically unstable patients

    Microsoft Academic Search

    F. D. Compton; B. Zukunft; C. Hoffmann; W. Zidek; J.-H. Schaefer

    2008-01-01

    Background. Early haemodynamic assessment is of particular importance in the evaluation of haemodynamically compromised patients, but is often precluded by the invasiveness and com- plexity of the established cardiac output (CO) monitoring techniques. The FloTrac TM \\/Vigileo TM system allows minimally invasive CO determination based on the arterial pressure waveform derived from any standard arterial catheter, and the algorithm underlying

  12. Echocardiographic assessment of cardiac disease

    NASA Technical Reports Server (NTRS)

    Popp, R. L.

    1976-01-01

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

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

    PubMed Central

    Kang, Dongyel; Huang, Qiaojian; Li, Youzhi

    2014-01-01

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

  14. Lithium dilution cardiac output measurement in the critically ill patient: determination of precision of the technique

    Microsoft Academic Search

    M. Cecconi; D. Dawson; R. M. Grounds; A. Rhodes

    2009-01-01

    Background  Lithium dilution cardiac output by LiDCO™plus (LiDCO, Cambridge, UK) is a validated methodology for measuring cardiac output. It is used to calibrate a pulse pressure\\u000a analysis algorithm (PulseCO) for the continuous measurement of subsequent changes in this variable. The variability of measurements,\\u000a or precision, within patients of lithium dilution cardiac output has not previously been described.\\u000a \\u000a \\u000a \\u000a Material and methods  Thirty-five hemodynamically

  15. Chronic resuscitation after trauma-hemorrhage and acute fluid replacement improves hepatocellular function and cardiac output.

    PubMed Central

    Remmers, D E; Wang, P; Cioffi, W G; Bland, K I; Chaudry, I H

    1998-01-01

    OBJECTIVE: To determine whether prolonged (chronic) resuscitation has any beneficial effects on cardiac output and hepatocellular function after trauma-hemorrhage and acute fluid replacement. BACKGROUND DATA: Acute fluid resuscitation after trauma-hemorrhage restores but does not maintain the depressed hepatocellular function and cardiac output. METHODS: Male Sprague-Dawley rats underwent a 5-cm laparotomy (i.e., trauma was induced) and were bled to and maintained at a mean arterial pressure of 40 mmHg until 40% of maximal bleed-out volume was returned in the form of Ringer's lactate (RL). The animals were acutely resuscitated with RL using 4 times the volume of maximum bleed-out over 60 minutes, followed by chronic resuscitation of 0, 5, or 10 mL/kg/hr RL for 20 hours. Hepatocellular function was determined by an in vivo indocyanine green clearance technique. Hepatic microvascular blood flow was assessed by laser Doppler flowmetry. Plasma levels of interleukin-6 (IL-6) were determined by bioassay. RESULTS: Chronic resuscitation with 5 mL/kg/hr RL, but not with 0 or 10 mL/kg/hr RL, restored cardiac output, hepatocellular function, and hepatic microvascular blood flow at 20 hours after hemorrhage. The regimen above also reduced plasma IL-6 levels. CONCLUSION: Because chronic resuscitation with 5 mL/kg/hr RL after trauma-hemorrhage and acute fluid replacement restored hepatocellular function and hepatic microvascular blood flow and decreased plasma levels of IL-6, we propose that chronic fluid resuscitation in addition to acute fluid replacement should be routinely used in experimental studies of trauma-hemorrhage. PMID:9445118

  16. Continuous determination of cardiac output during exercise by the use of impedance plethysmography

    Microsoft Academic Search

    Y. Miyamoto; M. Takahashi; T. Tamura; T. Nakamura; T. Hiura; M. Mikami

    1981-01-01

    A computer-based system has been developed that enables the continuous measurement of cardiac output at rest as well as during\\u000a exercise. The respiratory and motion artefacts appearing in the first derivative of the transthoracic impedance change (dZ\\/dt)\\u000a were eliminated by adopting an ensemble averaging technique. A sufficiently high correlation was observed between cardiac\\u000a outputs determined by the impedance and CO2

  17. Clinical validation of the non-invasive cardiac output monitor USCOM-1A in critically ill patients

    Microsoft Academic Search

    L. E. M. van Lelyveld-Haas; A. R. H. van Zanten; G. F. Borm; D. H. T. Tjan

    2008-01-01

    BACKGROUND AND OBJECTIVE: Cardiac output is frequently monitored to maintain and improve cardiac function with the primary goal of adequate tissue perfusion. The pulmonary artery catheter is considered to be the gold standard although several non-invasive devices are being introduced and gaining attention. To evaluate the accuracy of the ultrasonic cardiac output monitor (USCOM)-1A (Pty Ltd, Coffs Harbour, NSW, Australia),

  18. Non-invasive ultrasonic cardiac output monitoring in exercise testing

    Microsoft Academic Search

    Karsten Knobloch; Volker Hoeltke; Ernst Jakob; Peter M. Vogt; Rob Phillips

    2008-01-01

    BackgroundThe purpose of this study was to evaluate the relationship of breath-by-breath oxygen uptake (VO2) and CO, cardiac index (CI), stroke volume (SV) and heart rate (HR) determined by a non-invasive continuous wave (CW) Doppler-based system (USCOM) in healthy adolescent and adult athletes during exercise treadmill testing.

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

    PubMed Central

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

    2007-01-01

    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 (?COPAC) and percentage changes in COAP (?COAP) for consecutive measurements was -0.70% ± 32.28%. COPAC and COAP showed a Pearson correlation coefficient of 0.58 (p < 0.01), while the correlation coefficient between ?COPAC and ?COAP was 0.46 (p < 0.01). 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 demonstrate an acceptable accuracy in comparison to the clinical standard of cardiac output determination. PMID:17996086

  20. Comparison between Flotrac-Vigileo and Bioreactance, a totally noninvasive method for cardiac output monitoring

    Microsoft Academic Search

    Sophie Marqué; Alain Cariou; Jean-Daniel Chiche; Pierre Squara

    2009-01-01

    ABSTRACT: INTRODUCTION: This study was designed to compare the clinical acceptability of two cardiac output (CO) monitoring systems: a pulse wave contour-based system (FloTrac-Vigileo) and a bioreactance-based system (NICOM), using continuous thermodilution (PAC-CCO) as a reference method. METHODS: Consecutive patients, requiring PAC-CCO monitoring following cardiac surgery, were also monitored by the two other devices. CO values obtained simultaneously by the

  1. Thoracic electrical bioimpedance: a non-invasive measure of cardiac output for porcine research.

    PubMed

    Broomhead, C J; Wright, S J; Kiff, K M; Withington, P S

    1998-07-01

    A comparison of two techniques for measuring cardiac output, thermodilution (TD) and thoracic electrical bioimpedance (TEB), was undertaken in a porcine model. Eight anaesthetized large white pigs were studied. A total of 436 paired measurements were performed over a range of cardiac outputs from 1.7 to 15.1 l/min as measured by thermodilution. The Pearson product moment correlation coefficient was r = 0.963 with P < 0.001. Analysis by Bland and Altman statistics revealed a mean difference (bias) of -0.02 l/min and the limits of agreement were +/- 1.6 l/min, similar to figures found in human comparative studies. These results confirm that thoracic electrical bioimpedance is a valid method of measuring cardiac output in pigs. It has significant advantages compared to thermodilution, in particular it is cheap, simple to use, non-invasive and provides continuous data. PMID:9718481

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

    PubMed Central

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

    2009-01-01

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

  3. Doppler Ultrasound Determination of the Distribution of Human Cardiac Output: Effects of Age and Physical Stresses

    Microsoft Academic Search

    E. R. Greene; R. C. Roach

    2004-01-01

    Due to its high spatial, temporal, and dynamic resolution, noninvasive Doppler ultrasound can be used to determine the distribution of phasic cardiac output in humans. The effects of ageing and various common physical stresses on combined human major central and regional blood flows have not been reported. We tested the hypothesis that there are no significant age-related differences in steady-state

  4. Serial changes in cardiac output during normal pregnancy: a Doppler ultrasound study

    Microsoft Academic Search

    Terence G. Hennessy; Dermot MacDonald; Marie S. Hennessy; Margaret Maguire; Sean Blake; Hugh A. McCann; Declan D. Sugrue

    1996-01-01

    Objectives: To determine the direction and magnitude of change in cardiac output (CO) during pregnancy. Study design: We performed serial measurements of CO on five occasions from 24 weeks gestation to term and once during the puerperium in 26 normal pregnancies (156 measurements) using Doppler ultrasound measurement of flow velocity profiles and aortic root cross sectional area. Result: CO increased

  5. Real-time cardiac output estimation of the circulatory system under left ventricular assistance

    Microsoft Academic Search

    Makoto Yoshizawa; Hiroshi Takeda; Makoto Miura; Tomoyuki Yambe; Yoshiaki Katahira; Shin-ichi Nitta

    1993-01-01

    A method for indirect and real-time estimation of the cardiac output of the circulatory system supported by the left ventricular assist device (LVAD) is proposed. This method has low invasiveness and is useful for clinical applications of the LVAD since it needs only two measurements: the rate of blood outflow from the LVAD and the aortic pressure. The method is

  6. Changes in cardiac output during swimming and aquatic hypoxia in the air-breathing Pacific tarpon

    E-print Network

    Farrell, Anthony P.

    aorta to monitor Vb and with a fibre-optic oxygen sensor in the ABO to monitor air-breathing frequencyChanges in cardiac output during swimming and aquatic hypoxia in the air-breathing Pacific tarpon T online 1 August 2007 Abstract Pacific tarpon (Megalops cyprinoides) use a modified gas bladder as an air-breathing

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

    NASA Technical Reports Server (NTRS)

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

    1976-01-01

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

  8. THE EFFECT OF EXERCISE ON THE CARDIAC OUTPUT AND BLOOD FLOW DISTRIBUTION OF THE LARGESCALE SUCKER CATOSTOMUS MACROCHEILUS

    Microsoft Academic Search

    ALAN S. KOLOK; R. MICHAEL SPOONER; ANTHONY P. FARRELL

    Summary Cardiac output (Q. ) and blood flow distribution were measured in adult largescale suckers at rest and while swimming. Cardiac output was directly measured using an ultrasonic flowprobe in f ish during the summer (16?C), fall (10?C) and winter (5?C). Largescale suckers were adept at holding station against a current without swimming and, when engaged in this behavior, they

  9. Oesophageal Doppler cardiac output monitoring: a longstanding tool with evolving indications and applications.

    PubMed

    Colquhoun, Douglas A; Roche, Anthony M

    2014-12-01

    Much work has been done over the years to assess cardiac output and better grasp haemodynamic profiles of patients in critical care and during major surgery. Pulmonary artery catheterization has long been considered as the standard of care, especially in critical care environments, however this dogma has been challenged over the last 10-15 years. This has led to a greater focus on alternate, lesser invasive technologies. This review focuses on the scientific and clinical outcomes basis of oesophageal Doppler monitoring. The science underpinning Doppler shift assessment of velocity stretches back over 100 years, whereas the clinical applicability, and specifically clinical outcomes improvement can be attributed to the last 20 years. Oesophageal Doppler monitoring (ODM), and its associated protocol-guided fluid administration, has been shown to reduce complications, length of stay, and overall healthcare cost when incorporated into perioperative fluid management algorithms. However, more recent advances in enhanced recovery after surgery programs have led to similar improvements, leading the clinician to consider the role of Oesophageal Doppler Monitor to be more focused in high-risk surgery and/or the high-risk patient. PMID:25480766

  10. Hybrid measurement to achieve satisfactory precision in perioperative cardiac output monitoring.

    PubMed

    Peyton, P

    2014-05-01

    Advanced haemodynamic monitoring employing minimally invasive cardiac output measurement may lead to significant improvements in patient outcomes in major surgery. However, the precision (scatter) of measurement of available generic technologies has been shown to be unsatisfactory with percentage error of agreement with bolus thermodilution (% error) of 40% to 50%. Simultaneous measurement and averaging by two or more technologies may reduce random measurement scatter and improve precision. This concept, called the hybrid method, was tested by comparing accuracy and precision of measurement relative to bolus thermodilution using combinations of three component methods. Thirty patients scheduled for either elective cardiac surgery or liver transplantation were studied. Agreement with simultaneous bolus thermodilution of hybrid combinations of continuous thermodilution (QtCCO) or Vigeleo™/FloTrac™ pulse contour measurement (QtFT) with pulmonary Capnotracking (QtCO2) was assessed pre- and post-cardiopulmonary bypass or pre- and post-reperfusion of the donor liver and compared with that of the component methods alone. Hybridisation of QtCO2 (% error 42.2) and QtCCO (% error 51.3) achieved significantly better precision (% error 31.3) than the component methods (P=0.0004) and (P=0.0195). Due to poor inherent precision of QtFT (% error 82.8), hybrid combination of QtFT with QtCO2 did not result in better precision than QtCO2 alone. Hybrid measurement can approach a 30% error, which is recommended as the upper limit for acceptability. This is a practical option where at least one component method, such as Capnotracking, is automated and does not increase the cost or complexity of the measurement process. PMID:24794474

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

    PubMed

    Peyton, Philip J

    2012-04-01

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

  12. A comparison of pulse contour wave analysis and ultrasonic cardiac output monitoring in the critically ill.

    PubMed

    Udy, A A; Altukroni, M; Jarrett, P; Roberts, J A; Lipman, J

    2012-07-01

    Cardiac output (CO) is a key determinant of major organ blood flow and solute delivery to drug eliminating organs. As such, CO assessment is a key covariate in understanding altered drug handling in the critically ill. Newer minimally-invasive devices are providing unique platforms for such an application, although comparison data are currently lacking. In this study we evaluated the Vigileo (Edwards Lifesciences, Irvine, CA, USA) and USCOM (USCOM Ltd, Sydney, NSW) devices in 62 critically ill patients requiring antibacterial therapy. The mean COVigileo and COUSCOM for the first paired measurements were 8.20±2.65 l/minute and 6.84±2.57 l/minute respectively (P <0.001). A significant correlation was evident in all patients (r=0.537, P <0.001) although the recorded bias was large (1.36±2.51 l/minute, limits of agreement -3.6 to±6.3 l/minute). The overall percentage error was 65%. There was an improved correlation in those admitted with sepsis (r=0.639, P <0.001), compared to trauma (r=0.373, P=0.066), although bias, precision and percentage error were similar in both subgroups. In 54 patients a second paired assessment was obtained at three hours. A weak, although significant correlation (r=0.377, P=0.005) was observed suggesting that gross trends over time were similar. In conclusion, our findings demonstrate poor agreement between these techniques suggesting that these devices are not simply interchangeable when assessing CO in a research or clinical setting. PMID:22813490

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

    PubMed

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

    2014-02-01

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

  14. Pressure Pulse Contour-derived Stroke Volume and Cardiac Output in the Morbidly Obese Patient

    Microsoft Academic Search

    Donald P. Bernstein

    2008-01-01

    Background  The pressure pulse contour method for measuring stroke volume (SV) and cardiac output (CO) has come of age. Various methods\\u000a have been proposed, but at this time no single technique has shown clear superiority over the others. This commentary and\\u000a review discusses the various methods, and particularly the pressure recording analytical method (PRAM). Dissection of the\\u000a method shows that vascular

  15. Continuous intraoperative noninvasive cardiac output monitoring using a new thoracic bioimpedance device

    Microsoft Academic Search

    Duraiyah Thangathurai; Christopher Charbonnet; Peter Roessler; Charles C. J. Wo; Maged Mikhail; Roland Yoshida; William C. Shoemaker

    1997-01-01

    Objectives: To compare a new noninvasive bioimpedance device with the standard thermodilution method during the intraoperative period in high-risk patients undergoing oncological surgery.Design: Prospectively collected data with retrospective analysis.Setting: The study was undertaken at a university hospital, single institution.Participants: Twenty-three selected adults undergoing extensive, ablative oncological surgery.Interventions: Simultaneous measurements of cardiac output by a new bioimpedance method and the standard

  16. [Application of pulse contour cardiac output monitoring technique in hemodynamic monitoring in critical patients].

    PubMed

    Fang, He; Zheng, Xingfeng; Xia, Zhaofan

    2014-08-01

    Pulse contour cardiac output (PiCCO) monitoring is a new type of invasive hemodynamic monitoring technology, which is more and more often applied in perioperative period and the patients suffering from multiple injuries, septic shock, and extensive burn. With PiCCO one is able to monitor patients' hemodynamic indexes safely, timely, accurately, and continuously to provide reference for judgment of patients' condition and proper quality and quantity of fluid administration. This technique has a good prospect in clinical application. PMID:25429813

  17. Flow velocity profile of the pulmonary artery measured by the continuous cardiac output monitoring catheter

    Microsoft Academic Search

    Keiko Miyasaka; Masao Takata; Katsuyuki Miyasaka MO

    1993-01-01

    The KATS catheter (continuous arterial thermodeprivation system catheter) measures the blood flow velocity of the pulmonary\\u000a artery (PA) by thermodeprivation which enables continuous determination of cardiac output. The accuracy of this system may\\u000a depend on the degree of uniformity of flow velocity in the PA, because small movements of the catheter within the PA are inevitable\\u000a with a beating heart.

  18. [Application of pulse contour cardiac output monitoring technique in hemodynamic monitoring in critical patients].

    PubMed

    Fang, He; Zheng, Xingfeng; Xia, Zhaofan

    2014-08-01

    Pulse contour cardiac output (PiCCO) monitoring is a new type of invasive hemodynamic monitoring technology, which is more and more often applied in perioperative period and the patients suffering from multiple injuries, septic shock, and extensive burn. With PiCCO one is able to monitor patients' hemodynamic indexes safely, timely, accurately, and continuously to provide reference for judgment of patients' condition and proper quality and quantity of fluid administration. This technique has a good prospect in clinical application. PMID:25508030

  19. Cardiac output monitoring during off-pump coronary artery bypass grafting

    Microsoft Academic Search

    Matthew P Grow; Amrik Singh; Neal W Fleming; Nilas Young; Mitchell Watnik

    2004-01-01

    Objective: To evaluate and compare monitors of cardiac output during repositioning and stabilization of the heart for off-pump coronary artery bypass (OPCAB) surgery.Design: Prospective, observational, clinical study.Setting: University teaching hospital.Participants: Consecutive patients scheduled to undergo elective OPCAB (n = 19).Interventions: Monitoring, induction, and anesthesia followed a routine protocol for coronary artery bypass patients. This included the use of transesophageal echocardiography

  20. [Noninvasive measurement of cardiac output by pulsed Doppler echocardiography. Correlation with thermodilution].

    PubMed

    Dericbourg, C; Tribouilloy, C; Kugener, H; Avinee, P; Rey, J L; Lesbre, J P

    1990-02-01

    Cardiac output was measured simultaneously by pulsed Doppler echocardiography and thermodilution in 22 patients, 18 of whom also underwent atrial pacing at different rates to give a total of 42 different measurements. The aortic diameter was measured firstly at the aortic ring at the level of insertion of the aortic cusps and then at the point of maximum separation of the valve cups in the left parasternal long-axis view. The aortic velocities were recorded in the apical 5-chamber view immediately below the level of the aortic valve. The correlations obtained at the aortic ring (R1) and at the point of maximum separation of the valve cusps (R2) were 0.77 (y = 0.67x + 1.17: standard error = 0.81 l/m) and 0.64 (y = 0.56x + 0.87; standard error = 1.01 l/mn) respectively. The correlations were much better when 7 technically unsatisfactory measurements were excluded (R2 = 0.76: y = 0.59x + 0.74: standard error = 0.79 l/mn) (R1 = 0.87: y = 0.72x + 1.04: standard error = 0.65 l/mn). THe correlations of stroke volume measured at aortic ring level also improved from r = 0.82 (y = 0.75x + 7.29: standard error = 8.9 ml) to r = 0.89 (y = 0.78x + 7.38: standard error = 7.3 ml). The measurement of cardiac output by pulsed Doppler echocardiography in the aortic root seems to be reliable. The correlations of the values of stroke volume and cardiac output with the thermodilution method are good, allowing detection of beat-to-beat variations of cardiac output, in suitable patients in the hands of experienced operators. PMID:2106860

  1. Measurement of cardiac output using near-infrared heating of blood

    NASA Astrophysics Data System (ADS)

    Curley, Michael G.; Hamilton, Patrick S.; Walsh, Joseph T., Jr.

    1997-05-01

    Thermodilution-based cardiac output measurements are made using iced saline or blood heated by resistive heating as a dilutable indicator. Because near-infrared irradiation penetrates sufficiently deeply into blood, it can safely deposit up to six times the energy of a resistive heater, improving the accuracy of the measurements while continuously monitoring cardiac output. We have developed a prototype system using 980 nm diode lasers to irradiate blood through a diffuser. This system was tested using an optical blood phantom and was compared to iced-saline injection and resistive heating. Three flow estimates were made at each of 18 combinations of stroke rate, stroke volume, and systole/diastole ratios. Accuracy was determined by the quality of the fit between the estimated flows and the actual flow. Reproducibility was determined by the normalized standard deviation. Results: Measurements made by saline injection were the most accurate (R2 equals 0.982) and reproducible (NSD equals 2.8%). Power limitations on the resistive heating to ensure a safe blood temperature limited its accuracy (R2 equals 0.537) and reproducibility (NSD equals 18.1%). Laser-based heating showed reasonable accuracy and reproducibility (R2 equals 0.950, NSD equals 7.8%). Laser heating thus represents a potentially more accurate alternative to saline injection for cardiac output measurement than does resistive heating.

  2. End-tidal CO2 for prediction of cardiac output following weaning from cardiopulmonary bypass.

    PubMed

    Baraka, Anis S; Aouad, Marie T; Jalbout, Maya I; Kaddoum, Roland N; Khatib, Mohammad F; Haroun-Bizri, Sania T

    2004-09-01

    This prospective study included 32 patients undergoing cardiopulmonary bypass (CPB) for elective coronary artery bypass grafting correlates the respiratory end-tidal CO2 (ETCO2) during partial separation from CPB with cardiac output (CO) following weaning from CPB. After induction of general anesthesia, a pulmonary artery catheter was inserted for measurement of cardiac output by thermodilution. Patients were monitored using a 5-lead ECG, pulse oximeter, invasive blood pressure monitoring, rectal temperature probe, and end-tidal capnography. At the end of surgery, patients were weaned from CPB in a stepwise fashion. Respiratory ETCO2 and in-line venous oximetry were continuously monitored during weaning. The ETCO2 was recorded at quarter pump flow and after complete weaning from CPB. Following weaning from CPB, CO was measured by thermodilution. The CO values were correlated with the ETCO2 during partial bypass and following weaning from bypass. Regression analysis of ETCO2 at quarter-flow and post-bypass CO showed significant correlation (r = 0.57, p < .001). Also, regression analysis of ETCO2 after complete weaning from bypass and post-bypass CO showed significant correlation (r = 0.6, p = .002). The correlation between ETCO2 and CO showed that an ETCO2 >30 mm Hg during partial CPB will always predict an adequate CO following weaning from CPB. An ETCO2 <30 mm Hg may denote either a low or a normal cardiac output and hence other predictive parameters such as SvO2 must be added. PMID:15559744

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

    NASA Technical Reports Server (NTRS)

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

    1986-01-01

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

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

    PubMed Central

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

    2012-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2014-03-01

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

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

    PubMed

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

    2014-03-19

    Contrast enhancement on cardiac CT provides valuable information about myocardial perfusion and methods have been proposed to assess perfusion with static and dynamic acquisitions. There is a lack of knowledge and consensus on the appropriate approach to ensure 1) sufficient diagnostic accuracy for clinical decisions and 2) low radiation doses for patient safety. This work developed a thorough dynamic CT simulation and several accepted blood flow estimation techniques to evaluate the performance of perfusion assessment across a range of acquisition and estimation scenarios. Cardiac CT acquisitions were simulated for a range of flow states (Flow = 0.5, 1, 2, 3 ml/g/min, cardiac output = 3,5,8 L/min). CT acquisitions were simulated with a validated CT simulator incorporating polyenergetic data acquisition and realistic x-ray flux levels for dynamic acquisitions with a range of scenarios including 1, 2, 3 sec sampling for 30 sec with 25, 70, 140 mAs. Images were generated using conventional image reconstruction with additional image-based beam hardening correction to account for iodine content. Time attenuation curves were extracted for multiple regions around the myocardium and used to estimate flow. In total, 2,700 independent realizations of dynamic sequences were generated and multiple MBF estimation methods were applied to each of these. Evaluation of quantitative kinetic modeling yielded blood flow estimates with an root mean square error (RMSE) of ?0.6 ml/g/min averaged across multiple scenarios. Semi-quantitative modeling and qualitative static imaging resulted in significantly more error (RMSE = ?1.2 and ?1.2 ml/min/g respectively). For quantitative methods, dose reduction through reduced temporal sampling or reduced tube current had comparable impact on the MBF estimate fidelity. On average, half dose acquisitions increased the RMSE of estimates by only 18% suggesting that substantial dose reductions can be employed in the context of quantitative myocardial blood flow estimation. In conclusion, quantitative model-based dynamic cardiac CT perfusion assessment is capable of accurately estimating MBF across a range of cardiac outputs and tissue perfusion states, outperforms comparable static perfusion estimates, and is relatively robust to noise and temporal subsampling. PMID:25395812

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

    PubMed Central

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

    2015-01-01

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

  8. Impedance cardiography by use of a spot-electrode array to track changes in cardiac output in anesthetized dogs.

    PubMed

    Kiesler, T W; Voorhees, W D; Wessale, J L; Pham, C K

    1990-06-01

    Transthoracic impedance cardiography is a noninvasive method to determine changes in cardiac output on the basis of the cardiac-induced impedance change measured across the thorax. In this report, we describe a new, easily applied, tetrapolar spot-electrode configuration for use in canine transthoracic impedance cardiography. The array is a convenient alternative to use of the traditional circumferential band-electrode array which, in the dog, is prohibitive because of the extensive skin preparation required. The spot-electrode array was used to compare changes in cardiac output measured by transthoracic impedance cardiography, with changes measured by a reference indicator-dilution technique. A spot-electrode array, composed of 4 standard ECG electrodes, was used to measure transthoracic impedance in 10 anesthetized dogs. Variations in cardiac output were produced by controlled hemorrhage (200- to 250-ml increments). Simultaneous reference measurements of cardiac output were made before hemorrhage (control) and at each level of hemorrhage, using the saline-dilution method. The beat-by-beat impedance changes were measured by use of a Minnesota impedance cardiograph, which also recorded the first derivative of impedance (dZ/dt). An index of cardiac output was defined as the product of the maximal value of the first time derivative of impedance, ejection time, and heart rate for each beat during inscription of a saline-dilution curve. The average of the beat-by-beat indices was calculated and then normalized relative to the initial control value. Linear regression analysis was performed to evaluate the correlation of the index of cardiac output with the reference cardiac output.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2351600

  9. Evaluation of the estimated continuous cardiac output monitoring system in adults and children undergoing kidney transplant surgery: a pilot study.

    PubMed

    Terada, Takashi; Maemura, Yumi; Yoshida, Akiko; Muto, Rika; Ochiai, Ryoichi

    2014-02-01

    Evaluation of the estimated continuous cardiac output (esCCO) allows non-invasive and continuous assessment of cardiac output. However, the applicability of this approach in children has not been assessed thus far. We compared the correlation coefficient, bias, standard deviation (SD), and the lower and upper 95 % limits of agreement for esCCO and dye densitography-cardiac output (DDG-CO) measurements by pulse dye densitometry (PDD) in adults and children. On the basis of these assessments, we aimed to examine whether esCCO can be used in pediatric patients. DDG-CO was measured by pulse dye densitometry (PDD) using indocyanine green. Modified-pulse wave transit time, obtained using pulse oximetry and electrocardiography, was used to measure esCCO. Correlations between DDG-CO and esCCO in adults and children were analyzed using regression analysis with the least squares method. Differences between the two correlation coefficients were statistically analyzed using a correlation coefficient test. Bland-Altman plots were used to evaluate bias and SD for DDG-CO and esCCO in both adults and children, and 95 % limits of agreement (bias ± 1.96 SD) and percentage error (1.96 SD/mean DDG-CO) were calculated and compared. The average age of the adult patients (n = 10) was 39.3 ± 12.1 years, while the average age of the pediatric patients (n = 7) was 9.4 ± 3.1 years (p < 0.001). For adults, the correlation coefficient was 0.756; bias, -0.258 L/min; SD, 1.583 L/min; lower and upper 95 % limits of agreement for DDG-CO and esCCO, -3.360 and 2.844 L/min, respectively; and percentage error, 42.7 %. For children, the corresponding values were 0.904; -0.270; 0.908; -2.051 and 1.510 L/min, respectively; and 35.7 %. Due to the high percentage error values, we could not establish a correlation between esCCO and DDG-CO. However, the 95 % limits of agreement and percentage error were better in children than in adults. Due to the high percentage error, we could not confirm a correlation between esCCO and DDG-CO. However, the agreement between esCCO and DDG-CO seems to be higher in children than in adults. These results suggest that esCCO can also be used in children. Future studies with bigger study populations will be required to further investigate these conclusions. PMID:23963774

  10. Continuous cardiac output monitoring after cardiopulmonary bypass: a comparison with bolus thermodilution measurement

    Microsoft Academic Search

    Karim Bendjelid; Nicolas Schütz; Peter M. Suter; Jacques-Andre Romand

    2006-01-01

    Objective  The interchangeability of continuous measurement of \\u000acardiac output (CO) with the traditional bolus method in patients after \\u000acardiopulmonary bypass (CPB) is uncertain.Design  Prospective observational clinical study.Setting  A 20-bed surgical ICU at a university \\u000ahospital.Patients  Fourteen deeply sedated, ventilated, post-cardiac surgery \\u000apatients, all equipped with a pulmonary artery catheter.Interventions  Six hours after the end of the CPB, 56 simultaneous \\u000abolus and continuous measurements were compared by a linear regression

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

    NASA Astrophysics Data System (ADS)

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

    2005-02-01

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

  12. Pulmonary carbon dioxide elimination for cardiac output monitoring in peri-operative and critical care patients: history and current status.

    PubMed

    Peyton, Philip J

    2013-01-01

    Minimally invasive measurement of cardiac output as a central component of advanced haemodynamic monitoring has been increasingly recognised as a potential means of improving perioperative outcomes in patients undergoing major surgery. Methods based upon pulmonary carbon dioxide elimination are among the oldest techniques in this field, with comparable accuracy and precision to other techniques. Modern adaptations of these techniques suitable for use in the perioperative and critical are environment are based on the differential Fick approach, and include the partial carbon dioxide rebreathing method. The accuracy and precision of this approach to cardiac output measurement has been shown to be similar to other minimally invasive techniques. This paper reviews the underlying principles and evolution of the method, and future directions including recent adaptations designed to deliver continuous breath-by-breath monitoring of cardiac output. PMID:23778012

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

    SciTech Connect

    Kelbaek, H.

    1989-05-01

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

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

    SciTech Connect

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

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

    PubMed Central

    Kang, DongYel; Huang, Qiaojian; Li, Youzhi

    2015-01-01

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

  16. Optimising the Windkessel model for cardiac output monitoring during changes in vascular tone.

    PubMed

    Charlton, Peter; Smith, John; Camporota, Luigi; Beale, Richard; Alastruey, Jordi

    2014-01-01

    Algorithms for estimating cardiac output (CO) from the arterial blood pressure wave have been observed to be inaccurate during changes in vascular tone. Many such algorithms are based on the Windkessel model of the circulation. We investigated the optimal analytical approaches and assumptions that make up each algorithm during changes in vascular tone. Several analytical approaches and assumptions were evaluated on data from 15 critically ill patients by comparison with thermodilution measurements. We found that the most accurate algorithms assumed a constant compliance for the duration of the beat. They produced a percentage error of ±31% by maintaining the compliance and outflow terms in the Windkessel model. For any algorithm, the following assumptions gave highest accuracy: (i) outflow pressure into the microcirculation is zero; (ii) end of systole is identified using the second derivative of pressure. None of the tested algorithms reached the clinically acceptable accuracy of ±30%. PMID:25570809

  17. Comparison between Flotrac-Vigileo and Bioreactance, a totally noninvasive method for cardiac output monitoring

    PubMed Central

    Marqué, Sophie; Cariou, Alain; Chiche, Jean-Daniel; Squara, Pierre

    2009-01-01

    Introduction This study was designed to compare the clinical acceptability of two cardiac output (CO) monitoring systems: a pulse wave contour-based system (FloTrac-Vigileo) and a bioreactance-based system (NICOM), using continuous thermodilution (PAC-CCO) as a reference method. Methods Consecutive patients, requiring PAC-CCO monitoring following cardiac surgery, were also monitored by the two other devices. CO values obtained simultaneously by the three systems were recorded continuously on a minute-by-minute basis. Results Continuous recording was performed on 29 patients, providing 12,099 simultaneous measurements for each device (417 ± 107 per patient). In stable conditions, correlations of NICOM and Vigileo with PAC-CCO were 0.77 and 0.69, respectively. The bias was -0.01 ± 0.84 for NICOM and -0.01 ± 0.81 for Vigileo (NS). NICOM relative error was less than 30% in 94% of the patients and less than 20% in 79% vs. 91% and 79% for the Vigileo, respectively (NS). The variability of measurements around the trend line (precision) was not different between the three methods: 8 ± 3%, 8 ± 4% and 8 ± 3% for PAC-CCO, NICOM and Vigileo, respectively. CO changes were 7.2 minutes faster with Vigileo and 6.9 minutes faster with NICOM (P < 0.05 both systems vs. PAC-CCO, NS). Amplitude of changes was not significantly different than thermodilution. Finally, the sensitivity and specificity for predicting significant CO changes were 0.91 and 0.95 respectively for the NICOM and 0.86 and 0.92 respectively for the Vigileo. Conclusions This study showed that the NICOM and Vigileo devices have similar monitoring capabilities in post-operative cardiac surgery patients. PMID:19454009

  18. Pulse contour cardiac output system use in pediatric orthotopic liver transplantation: preliminary report of nine patients.

    PubMed

    Torgay, A; Pirat, A; Akpek, E; Zeyneloglu, P; Arslan, G; Haberal, M

    2005-09-01

    Anesthetic management of orthotopic liver transplantation (OLT) in pediatric patients is challenging in terms of intraoperative bleeding, fluid management, and hemodynamic monitoring. The pulse contour cardiac output (PiCCO) system, a relatively new device based on the single-indicator transaortic thermodilution technique, may be useful for intraoperative hemodynamic monitoring in pediatric patients. This is a preliminary report of PiCCO use in nine children (aged 9.8 +/- 4.7 years) undergoing OLT. Hemodynamic volumetric parameters monitored by the PiCCO system were mean arterial pressure (MAP), cardiac index (CI), intrathoracic blood volume index (ITBVI), extravascular lung water index (EVLWI), systemic vascular resistance index (SVRI), and stroke volume variability (SVV). All parameters were recorded at anesthesia induction (T0), at the end of the anhepatic phase (Tanhepatic), and at the end of operation (Tend). The PiCCO system revealed similar MAP, CI, EVLWI, SVV, and SVRI values at all measurement intervals. Despite similar central venous pressure measurements, ITBVI values indicated significantly lower values at Tanhepatic than at T0 (627 +/- 160 mL/m2 and 751 +/- 151 mL/m2, respectively, P = .013). There were no PiCCO catheter-related complications in any patient. These findings demonstrate that the PiCCO system is a safe, continuous, multiparameter invasive monitoring device for use in pediatric patients undergoing OLT. This system may provide valuable data during pediatric OLT and appears to be a promising monitoring tool in these patients. PMID:16213339

  19. Influence of levosimendan, pimobendan, and milrinone on the regional distribution of cardiac output in anaesthetized dogs.

    PubMed Central

    Pagel, P. S.; Hettrick, D. A.; Warltier, D. C.

    1996-01-01

    1. The distribution of cardiac output during administration of levosimendan, a new myofilament calcium sensitizer, is unknown. We examined and compared the effects of levosimendan, pimobendan, and milrinone on regional tissue perfusion by use of the radioactive microsphere technique in barbiturate-anaesthetized dogs. 2. Haemodynamics and regional blood flow were determined before and during infusions of levosimendan (0.75, 1.5, and 3.0 micrograms kg-1 min-1), pimobendan (10, 20, and 40 micrograms kg-1 min-1), or milrinone (1.0, 2.0, and 4.0 micrograms kg-1 min-1). 3. All three drugs caused similar increases in heart rate, cardiac output, and left ventricular +dP/dt and decreases in end-diastolic pressure and systemic vascular resistance. No changes in subendocardial, midmyocardial, and subepicardial blood flow occurred during administration of levosimendan. However, a redistribution of blood flow from subendocardium to subepicardium was observed. Pimobendan increased midmyocardial and subepicardial blood flow and reduced the endo/epi ratio to a greater degree than levosimendan. Milrinone did not affect myocardial perfusion. 4. Levosimendan increased blood flow to the renal medulla and decreased renal medullary and cortical vascular resistance. Levosimendan increased blood flow to the small intestine and liver and reduced vascular resistance in these organs. Pimobendan increased hepatic blood flow to a greater degree than levosimendan but did not alter small intestinal perfusion. All three drugs decreased splenic blood flow to similar degrees. Levosimendan and pimobendan reduced cerebral vascular resistance. Levosimendan and milrinone reduced skeletal muscle vascular resistance. 5. The results indicate that levosimendan, pimobendan, and milrinone cause subtlety different alterations in regional tissue perfusion while producing similar haemodynamic effects. PMID:8894186

  20. Arterial pressure-based cardiac output in septic patients: different accuracy of pulse contour and uncalibrated pressure waveform devices

    PubMed Central

    2010-01-01

    Introduction We compared the ability of two devices estimating cardiac output from arterial pressure-curve analysis to track the changes in cardiac output measured with transpulmonary thermodilution induced by volume expansion and norepinephrine in sepsis patients. Methods In 80 patients with septic circulatory failure, we administered volume expansion (40 patients) or introduced/increased norepinephrine (40 patients). We measured the pulse contour-derived cardiac index (CI) provided by the PiCCO device (CIpc), the arterial pressure waveform-derived CI provided by the Vigileo device (CIpw), and the transpulmonary thermodilution CI (CItd) before and after therapeutic interventions. Results The changes in CIpc accurately tracked the changes in CItd induced by volume expansion (bias, -0.20 ± 0.63 L/min/m2) as well as by norepinephrine (bias, -0.05 ± 0.74 L/min/m2). The changes in CIpc accurately detected an increase in CItd ? 15% induced by volume expansion and norepinephrine introduction/increase (area under ROC curves, 0.878 (0.736 to 0.960) and 0.924 (0.795 to 0.983), respectively; P < 0.05 versus 0.500 for both). The changes in CIpw were less reliable for tracking the volume-induced changes in CItd (bias, -0.23 ± 0.95 L/min/m2) and norepinephrine-induced changes in CItd (bias, -0.01 ± 1.75 L/min/m2). The changes in CIpw were unable to detect an increase in CItd ? 15% induced by volume expansion and norepinephrine introduction/increase (area under ROC curves, 0.564 (0.398 to 0.720) and 0.541 (0.377 to 0.700, respectively, both not significantly different from versus 0.500). Conclusions The CIpc was reliable and accurate for assessing the CI changes induced by volume expansion and norepinephrine. By contrast, the CIpw poorly tracked the trends in CI induced by those therapeutic interventions. PMID:20537159

  1. The decreased oxygen uptake during progressive exercise in ischemia-induced heart failure is due to reduced cardiac output rate

    Microsoft Academic Search

    N. P. L. Rolim; K. C. Mattos; P. C. Brum; M. V. C. Baldo; H. R. Middlekauff; C. E. Negrão

    2006-01-01

    We tested the hypothesis that the inability to increase cardiac output during exercise would explain the decreased rate of oxygen uptake (VO2) in recent onset, ischemia-induced heart failure rats. Nine nor- mal control rats and 6 rats with ischemic heart failure were studied. Myocardial infarction was induced by coronary ligation. VO2 was measured during a ramp protocol test on a

  2. Cardiac Output Measurement in Patients Undergoing Liver Transplantation: Pulmonary Artery Catheter Versus Uncalibrated Arterial Pressure Waveform Analysis

    Microsoft Academic Search

    Biais Matthieu; Nouette-Gaulain Karine; Cottenceau Vincent; Vallet Alain; Cochard Jean François; Revel Philippe; Sztark François

    2008-01-01

    BACKGROUND: Cardiac output (CO) and invasive hemodynamic measurements are useful during liver transplantation. The pulmonary artery catheter (PAC) is commonly used for these patients, despite the potential complications. Recently, a less invasive device (Vigileo®\\/FloTrac™) became available, which estimates CO using arterial pressure waveform analysis without external calibration. In this study, we compared CO obtained with a PAC using automatic thermodilution,

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

    Microsoft Academic Search

    Chirapa Puntawangkoon; Dalane W Kitzman; Stephen B Kritchevsky; Craig A Hamilton; Barbara Nicklas; Xiaoyan Leng; Peter H Brubaker; W Gregory Hundley

    2009-01-01

    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)

  4. Interrelationship between cardiac output and vascular resistance as determinants of effective arterial blood volume in cirrhotic patients

    Microsoft Academic Search

    Michael D Shapiro; Kathleen M Nicholls; Bertron M Groves; Rudiger Kluge; Hsaio-Min Chung; Daniel G Bichet; Robert W Schrier

    1985-01-01

    Interrelationship between cardiac output and vascular resistance as determinants of effective arterial blood volume in cirrhotic patients. The effect of head-out water immersion (HWI) in decompensated cirrhotic patients to correct sodium and water excretion has been found to be incomplete and variable. The explanation may be that the efficacy of HWI in correcting a decreased effective arterial blood volume (EABV)

  5. Non-invasive beat-to-beat cardiac output monitoring by an improved method of transthoracic bioimpedance measurement

    Microsoft Academic Search

    J. Fortin; W. Habenbacher; A. Heller; A. Hacker; R. Grüllenbergera; J. Innerhofer; H. Passath; Ch. Wagner; G. Haitchi; D. Flotzinger; R. Pacher; P. Wach

    2006-01-01

    The report describes a method of impedance cardiography using an improved estimate of thoracic volume. The formulas and their implementation in hardware and software are explained and new shortband electrodes are described which generate a good homogeneous thoracic field. Examples of stroke volume and cardiac output curves underline the capabilities of the monitoring system “Task Force® Monitor”. In several experiments,

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

    PubMed

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

    2015-07-01

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

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

    NASA Technical Reports Server (NTRS)

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

    1993-01-01

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

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

    PubMed Central

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

    2015-01-01

    Purpose We compared the efficacy of postoperative hemodynamic goal-directed therapy (GDT) using a pulmonary artery catheter (PAC) and bioreactance-based noninvasive cardiac output monitoring (NICOM) in patients with atrial fibrillation undergoing valvular heart surgery. Materials and Methods Fifty eight patients were randomized into two groups of GDT with common goals to maintain a mean arterial pressure of 60-80 mm Hg and cardiac index ?2 L/min/m2: the PAC group (n=29), based on pulmonary capillary wedge pressure, and the NICOM group (n=29), based on changes in stroke volume index after passive leg raising. The primary efficacy variable was length of hospital stay. Secondary efficacy variables included resource utilization including vasopressor and inotropic requirement, fluid balance, and major morbidity endpoints. Results Patient characteristics and operative data were similar between the groups, except that significantly more patients underwent double valve replacement in the NICOM group. The lengths of hospital stay were not different between the two groups (12.2±4.8 days vs. 10.8±4.0 days, p=0.239). Numbers of patients requiring epinephrine (5 vs. 0, p=0.019) and ventilator care >24 h (6 vs. 1, p=0.044) were significantly higher in the PAC group. The PAC group also required significantly larger amounts of colloid (1652±519 mL vs. 11430±463 mL, p=0.004). Conclusion NICOM-based postoperative hemodynamic GDT showed promising results in patients with atrial fibrillation undergoing valvular heart surgery in terms of resource utilization. PMID:26069111

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

    PubMed Central

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

    2014-01-01

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

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

    SciTech Connect

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

    1984-01-01

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

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

    PubMed

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

    2015-08-01

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

  12. Low cardiac output predicts development of hepatorenal syndrome and survival in patients with cirrhosis and ascites

    Microsoft Academic Search

    A Krag; F Bendtsen; J H Henriksen; S Møller

    2010-01-01

    Objectives:Recent studies suggest that cardiac dysfunction precedes development of the hepatorenal syndrome. In this follow-up study, we aimed to investigate the relation between cardiac and renal function in patients with cirrhosis and ascites and the impact of cardiac systolic function on survival.Patients and design:Twenty-four patients with cirrhosis and ascites were included. Cardiac function was investigated by gated myocardial perfusion imaging

  13. Arterial pressure-based cardiac output monitoring: a multicenter validation of the third-generation software in septic patients

    Microsoft Academic Search

    Daniel De Backer; Gernot Marx; Andrew Tan; Christopher Junker; Marc Van Nuffelen; Lars Hüter; Willy Ching; Frédéric Michard; Jean-Louis Vincent

    2011-01-01

    Purpose  Second-generation FloTrac software has been shown to reliably measure cardiac output (CO) in cardiac surgical patients. However,\\u000a concerns have been raised regarding its accuracy in vasoplegic states. The aim of the present multicenter study was to investigate\\u000a the accuracy of the third-generation software in patients with sepsis, particularly when total systemic vascular resistance\\u000a (TSVR) is low.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  Fifty-eight septic patients were

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

    PubMed

    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

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

    PubMed

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

    2013-12-01

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

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

    PubMed Central

    Horster, Sophia; Stemmler, Hans-Joachim; Strecker, Nina; Brettner, Florian; Hausmann, Andreas; Cnossen, Jitske; Parhofer, Klaus G.; Nickel, Thomas; Geiger, Sandra

    2012-01-01

    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 (n = 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 r = 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. PMID:22191019

  17. Retinal venous oxygen saturation and cardiac output during controlled hemorrhage and resuscitation.

    PubMed

    Denninghoff, Kurt R; Smith, Matthew H; Lompado, Art; Hillman, Lloyd W

    2003-03-01

    The objective was to test calibration of an eye oximeter (EOX) in a vitiligo swine eye and correlate retinal venous oxygen saturation (Srv(O(2))), mixed venous oxygen saturation (Sv(O(2))), and cardiac output (CO) during robust changes in blood volume. Ten anesthetized adult Sinclair swine with retinal vitiligo were placed on stepwise decreasing amounts of oxygen. At each oxygen level, femoral artery oxygen saturation (Sa(O(2))) and retinal artery oxygen saturation (Sra(O(2))) were obtained. After equilibration on 100% O(2), subjects were bled at 1.4 ml. kg(-1). min(-1) for 20 min. Subsequently, anticoagulated shed blood was reinfused at the same rate. During graded hypoxia, exsanguination, and reinfusion, Sra(O(2)) and Srv(O(2)) were measured by using the EOX, and CO and Sv(O(2)) were measured by using a pulmonary artery catheter. During graded hypoxia, Sra(O(2)) correlated with Sa(O(2)) (r = 0.92). Srv(O(2)) correlated with Sv(O(2)) (r = 0.89) during exsanguination and reinfusion. Sv(O(2)) and Srv(O(2)) correlated with CO during blood removal and resuscitation (r = 0.92). Use of vitiligo retinas improved the calibration of EOX measurements. In this robust hemorrhage model, Srv(O(2)) correlates with CO and Sv(O(2)) across the range of exsanguination and resuscitation. PMID:12571124

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

    PubMed

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

    2015-03-16

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

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

    PubMed Central

    2009-01-01

    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 < 0.001). After submaximal exercise, the change in superficial femoral LBF was reduced in HF participants (79 ± 92 ml/min) compared to healthy elderly (222 ± 108 ml/min; p = 0.002). This occurred even though submaximal stress-induced measures of the flow in the descending aorta (5.0 ± 1.2 vs. 5.1 ± 1.3 L/min; p = 0.87), and the stress-resting baseline difference in aortic flow (1.6 ± 0.8 vs. 1.7 ± 0.8 L/min; p = 0.75) were similar between the 2 groups. Importantly, the difference in submaximal exercise induced superficial femoral LBF between the 2 groups persisted after accounting for age, gender, body surface area, LVEF, and thigh muscle area (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. PMID:19922666

  20. First in vivo application and evaluation of a novel method for non-invasive estimation of cardiac output.

    PubMed

    Papaioannou, Theodore G; Soulis, Dimitrios; Vardoulis, Orestis; Protogerou, Athanase; Sfikakis, Petros P; Stergiopulos, Nikolaos; Stefanadis, Christodoulos

    2014-10-01

    Surgical or critically ill patients often require continuous assessment of cardiac output (CO) for diagnostic purposes or for guiding therapeutic interventions. A new method of non-invasive CO estimation has been recently developed, which is based on pressure wave analysis. However, its validity has been examined only in silico. Aim of this study was to evaluate in vivo the reproducibility and accuracy of the "systolic volume balance" method (SVB). Twenty two subjects underwent 2-D transthoracic echocardiography for CO measurement (reference value of CO). The application of SVB method required aortic pressure wave analysis and estimation of total arterial compliance. Aortic pulses were derived by mathematical transformation of radial pressure waves recorded by applanation tonometry. Total compliance was estimated by the "pulse pressure" method. The agreement, association, variability, bias and precision between Doppler and SVB measures of CO were evaluated by intraclass correlation coefficient (ICC), mean difference, SD of differences, percentage error (PR) and Bland-Altman analysis. SVB yielded very reproducible CO estimates (ICC=0.84, mean difference 0.27 ± 0.73 L/min, PR = 16.7%). SVB-derived CO was comparable with Doppler measurements, indicating a good agreement and accuracy (ICC = 0.74, mean difference = -0.22 ± 0.364 L/min, PR ? 15). The basic mathematical and physical principles of the SVB method provide highly reproducible and accurate estimates of CO compared with echocardiography. PMID:25108554

  1. Coregulation of Ion Channel Conductances Preserves Output in a Computational Model of a Crustacean Cardiac Motor Neuron

    PubMed Central

    Ball, John M.; Franklin, Clarence C.; Tobin, Anne-Elise

    2015-01-01

    Similar activity patterns at both neuron and network levels can arise from different combinations of membrane and synaptic conductance values. A strategy by which neurons may preserve their electrical output is via cell type-dependent balances of inward and outward currents. Measurements of mRNA transcripts that encode ion channel proteins within motor neurons in the crustacean cardiac ganglion recently revealed correlations between certain channel types. To determine whether balances of intrinsic currents potentially resulting from such correlations preserve certain electrical cell outputs, we developed a nominal biophysical model of the crustacean cardiac ganglion using biological data. Predictions from the nominal model showed that coregulation of ionic currents may preserve the key characteristics of motor neuron activity. We then developed a methodology of sampling a multidimensional parameter space to select an appropriate model set for meaningful comparison with variations in correlations seen in biological datasets. PMID:20573909

  2. EFFECTS OF THYROXINE AND GROWTH HORMONE TREATMENT OF DAIRY COWS ON MILK YIELD, CARDIAC OUTPUT AND MAMMARY BLOOD FLOW 1

    Microsoft Academic Search

    S. R. Davis; R. J. Collier; J. P. McNamara; H. H. Head; W. Sussman

    2010-01-01

    Four cows received thyroxine injections (T4; 20 mg\\/d) and three cows received growth hormone injec- tions (GH; 44 rag\\/d) for 4 d during successive 16-d experimental periods. Measurement was made of milk yield, protein yield, mammary tyrosine and phenylalanine uptake, blood plasma hormone concentrations, mammary blood flow and cardiac output. Milk yield increased by 25% with T4 and 21% with

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

    PubMed Central

    Sabzi, Feridoun; Faraji, Reza

    2015-01-01

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

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

    PubMed Central

    Neal, Maxwell Lewis; Bassingthwaighte, James B.

    2010-01-01

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

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

    PubMed Central

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

    2011-01-01

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

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

    PubMed Central

    Yoshida, T; Whipp, B J

    1994-01-01

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

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

    PubMed Central

    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

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

    PubMed

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

    2015-06-01

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

  9. Reduced cardiac output and its correlation with coronary blood flow and troponin in asphyxiated infants treated with therapeutic hypothermia.

    PubMed

    Sehgal, Arvind; Wong, Flora; Mehta, Shailender

    2012-10-01

    Perinatal asphyxia can lead to multi-organ insult which includes cardiovascular dysfunction. The objective was to study the relationship between cardiac function, perfusion and troponin. Unit database was accessed to identify infants with perinatal asphyxia over the last 2 years. Information from medical records and archived echocardiographic images was retrieved. Comparisons for echocardiographic information were made with healthy term infants. Seventeen infants with perinatal asphyxia were identified, of which three were excluded (one-33 weeks gestation, two-coagulopathy and pulmonary hypertension); 14 infants received therapeutic hypothermia. Median (range) gestation and birthweight were 39 (37-42) weeks and 3,550 (2,380-3,992) g respectively. Mean (S.D.) rectal temperature and time of echocardiogram were 33.5?±?0.5 °C and median (range) 7.7 h [3-10] respectively. Majority of infants had low biventricular outputs. Median (range) SVC flow was 29.8 ml/kg/min (13-96.2). Median (range) troponin was 0.77 ?g/L (0.17-2.6); normal???0.08 ?g/L. Markedly low coronary flows (diastolic VTI median (range) 2.1 (1.3-2.9) cm were noted compared to controls. Coronary flow had a significantly positive correlation with left ventricular output. Higher troponin levels were associated with lower aortic stroke velocity. A close association between cardiac output, perfusion and troponin was noted. A dichotomy between blood pressure and flow parameters was noted, indicating the wide variation in vascular resistance in these infants. Biventricular output, coronary and SVC flows were significantly higher in the control population. In conclusion, inter-variable relationship between cardiac output, coronary flow and troponin is an important addition to the understanding of cardiovascular impact of perinatal asphyxia. PMID:22669637

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

    PubMed Central

    Tuttle, Ann; Shore, Scott; Stone, Terry

    2009-01-01

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

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

    Microsoft Academic Search

    Alan Raybould; Ann Tuttle; Scott Shore; Terry Stone

    2010-01-01

    The environmental risks from cultivating crops producing output trait enzymes can be rigorously assessed by testing conservative\\u000a risk hypotheses of no harm to endpoints such as the abundance of wildlife, crop yield and the rate of degradation of crop\\u000a residues in soil. These hypotheses can be tested with data from many sources, including evaluations of the agronomic performance\\u000a and nutritional

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

    PubMed Central

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

    2012-01-01

    Background. The pulmonary artery catheter (PAC) is an accepted clinical method of measuring cardiac output (CO) despite no prior validation. The ultrasonic cardiac output monitor (USCOM) is a noninvasive alternative to PAC using Doppler ultrasound (CW). We compared PAC and USCOM CO measurements against a gold standard, the aortic flow probe (FP), in sheep at varying outputs. Methods. Ten conscious sheep, with implanted FPs, had measurements of CO by FP, USCOM, and PAC, at rest and during intervention with inotropes and vasopressors. Results. CO measurements by FP, PAC, and USCOM were 4.0 ± 1.2?L/min, 4.8 ± 1.5?L/min, and 4.0 ± 1.4?L/min, respectively, (n = 280, range 1.9?L/min to 11.7?L/min). Percentage bias and precision between FP and PAC, and FP and USCOM was ?17 and 47%, and 1 and 36%, respectively. PAC under-measured Dobutamine-induced CO changes by 20% (relative 66%) compared with FP, while USCOM measures varied from FP by 3% (relative 10%). PAC reliably detected ?30% but not +40% CO changes, as measured by receiver operating characteristic area under the curve (AUC), while USCOM reliably detected ±5% changes in CO (AUC > 0.70). Conclusions. PAC demonstrated poor accuracy and sensitivity as a measure of CO. USCOM provided equivalent measurements to FP across a sixfold range of outputs, reliably detecting ±5% changes. PMID:22649718

  13. Derivation of cardiac output and alveolar ventilation rate based on energy expenditure measurements in healthy males and females.

    PubMed

    Brochu, Pierre; Brodeur, Jules; Krishnan, Kannan

    2012-08-01

    Physiologically based pharmacokinetic modeling and occupational exposure assessment studies often use minute ventilation rates (VE), alveolar ventilation rates (VA) and cardiac outputs (Q) that are not reflective of the physiological variations encountered during the aggregate daytime activities of individuals from childhood to adulthood. These variations of VE, VA and Q values were determined for healthy normal-weight individuals aged 5-96?years by using two types of published individual data that were measured in the same subjects (n?=?902), namely indirect calorimetry measurements and the disappearance rates of oral doses of deuterium (²H) and heavy-oxygen (¹?O) in urine monitored by gas-isotope-ratio mass spectrometry. Arteriovenous oxygen content differences (0.051-0.082?ml of O? consumed ml?¹ of blood) and ratios of the physiological dead space to the tidal volume (0.232-0.419) were determined for oxygen consumption rates (0.157-0.806?l min?¹) required by minute energy expenditures ranging from 0.76 to 3.91?kcal min?¹. Generally higher values for the 2.5th up to the 99th percentile for VE (0.132-0.774?l kg?¹ min?¹, 4.42-21.69?l m?² min?¹), VA (0.093-0.553?l kg?¹ min?¹, 3.09-15.53?l m?² min?¹), Q (0.065-0.330?l kg?¹ min?¹, 2.17 to 9.46?l m?² min?¹) and ventilation-perfusion ratios (1.12-2.16) were found in children and teenagers aged 5-<16.5?years compared with older individuals. The distributions of cardiopulmonary parameters developed in this study should be useful in facilitating a scientifically sound characterization of the inter-individual differences in the uptake and health risks of lipophilic air pollutants, particularly as they relate to younger children. PMID:21365669

  14. Continuous cardiac output monitoring with an uncalibrated pulse contour method in patients supported with mechanical pulsatile assist device.

    PubMed

    Scolletta, Sabino; Miraldi, Fabio; Romano, Salvatore Mario; Muzzi, Luigi

    2011-07-01

    We evaluated the accuracy of an uncalibrated pulse contour method called Pressure Recording Analytical Method (PRAM) compared with continuous thermodilution for cardiac output (CO) monitoring in patients implanted with a pulsatile left ventricular assist device (LVAD). Twelve adult patients implanted with the HeartMate I-XVE device were studied. CO was simultaneously evaluated by PRAM and by continuous thermodilution. Blood flow values displayed by the LVAD's console were also used for the comparison. Bland-Altman and linear regression analyses were applied. A total of 72 CO measurements (range 3.8-6.7 l/min) were obtained. Mean CO was 5.23±0.70 l/min for the 'hot' pulmonary thermodilution (ThD-CCO) method, 5.28±0.63 l/min for PRAM and 4.83±0.67 l/min for LVAD-CO. A high correlation (r=0.90), a good agreement (mean bias -0.04 l/min, precision ±0.38 l/min) and a low percentage of error (7.3%) were observed between PRAM-CO and ThD-CCO. A good correlation was found between LVAD-CO and either ThD-CCO (r=0.88) or PRAM-CO (r=0.86), but an overestimation of 10% was observed for both PRAM-CO (mean bias -0.44 l/min) and ThD-CCO (mean bias -0.40 l/min). Our results demonstrated good agreements between PRAM-CO, ThD-CCO and LVAD-CO. PRAM derives CO from a peripheral artery without calibration and may be a complementary tool in the hemodynamic assessment of patients supported with a VAD. PMID:21454314

  15. Assessment of Cardiac Sarcoidosis with Advanced Imaging Modalities

    PubMed Central

    Akasaka, Takashi

    2014-01-01

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

  16. Clinical review: Guyton - the role of mean circulatory filling pressure and right atrial pressure in controlling cardiac output

    PubMed Central

    2010-01-01

    Arthur Guyton's concepts of the determinative role of right heart filling in cardiac output continue to be controversial. This paper reviews his seminal experiments in detail and clarifies the often confusing concepts underpinning his model. One primary criticism of Guyton's model is that the parameters describing venous return had not been measured in a functioning cardiovascular system in humans. Thus, concerns have been expressed in regard to the ability of Guyton's simplistic model, with few parameters, to model the complex human circulation. Further concerns have been raised in regard to the artificial experimental preparations that Guyton used. Recently reported measurements in humans support Guyton's theoretical and animal work. PMID:21144008

  17. Effects of enalapril on changes in cardiac output and organ vascular resistances induced by alpha 1- and alpha 2-adrenoceptor agonists in pithed normotensive rats.

    PubMed Central

    MacLean, M. R.; Hiley, C. R.

    1988-01-01

    1. Cardiac output, its distribution and regional vascular resistances were determined with tracer microspheres in pithed rats in the presence of the angiotensin converting enzyme inhibitor enalapril. The effects of enalapril on the cardiovascular responses elicited by either the alpha 1-adrenoceptor agonist phenylephrine or the alpha 2-adrenoceptor agonist xylazine were determined. 2. Enalapril decreased diastolic and mean blood pressure by decreasing cardiac index and total peripheral resistance. It induced vasodilatation in the kidney, epididimides, epididimidal fat and pancreas/mesentery. Vasoconstriction in the lungs, testes and liver was evident following enalapril administration as well as a decrease in the proportion of cardiac output passing to them, whilst the pancreas and mesentery received a greater proportion of the cardiac output. All the above effects of enalapril were reversed by infusion of angiotensin II at a rate of 75 ng kg-1 min-1. 3. Xylazine increased blood pressure by increasing both cardiac output and total peripheral resistance. Enalapril did not affect the increase in cardiac output caused by xylazine but decreased the effect of the alpha 2-agonist on blood pressure by preventing the increase in total peripheral resistance. Inhibition by enalapril of xylazine-induced vasoconstriction in the kidneys, testes, fat and gastrointestinal tract contributed to the decrease in total peripheral resistance. Enalapril also inhibited xylazine-induced changes in cardiac output distribution to the liver, lungs and heart. All the above effects of enalapril were reversed by infusion of angiotensin II. 4. Enalapril decreased the sustained phase of the pressor response to an infusion of phenylephrine whilst having no effect on the initial peak pressor response to a bolus injection of phenylephrine. Phenylephrine increased both cardiac output and total peripheral resistance and enalapril abolished its effect on total peripheral resistance whilst having no effect on the increase in cardiac output. Enalapril inhibited phenylephrine-induced vasoconstriction in the testes, fat, muscle, spleen and gastrointestinal tract. Enalapril also inhibited phenylephrine-induced changes in cardiac output distribution to the lungs and liver. The infusion of angiotensin II did not fully reverse the inhibitory effect of enalapril either on the phenylephrine-induced increases in diastolic blood pressure or on the vasoconstriction in the fat, spleen and gastrointestinal tract, but did reverse all other effects of enalapril.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:2899445

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

    PubMed Central

    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 stethoscope system. CO was measured using NICOM, a non-invasive CO measuring device. Ephedrine and beta blockers were administered to the subjects to compare changes in figures, and the change from using an inhalation anesthetic was also compared. Results: The S1 amplitude displayed positive correlation with the change rate of CO (r = 0.935, p < 0.001). The heart rate measured using the esophageal stethoscope and ECG showed considerably close figures through the Bland-Altman plot and showed a high positive correlation (r = 0.988, p < 0,001). Conclusion: In beagles, the amplitude of S1 had a significant correlation with changes in CO in a variety of situations. PMID:24772126

  19. Effects of Dobutamine on Left Ventricular Performance, Coronary Dynamics, and Distribution of Cardiac Output in Conscious Dogs

    PubMed Central

    Vatner, Stephen F.; McRitchie, Robert J.; Braunwald, Eugene

    1974-01-01

    The effects of dobutamine ([±]-4-[2-[[3-(p-hydroxyphenyl)-1-methyl propyl] amino] ethyl] pyrocatechol hydrochloride), a new synthetic cardioactive sympathomimetic amine, were examined on direct and continuous measurements of left ventricular (LV) diameter (D), pressures (P), velocity of shortening (V), dP/dt, dP/dt/P, arterial pressure, cardiac output, and regional blood flows in the left circumflex coronary, mesenteric, renal, and iliac beds in healthy, conscious dogs. At the highest dose of dobutamine examined, 40 ?g/kg/min, the drug increased dP/dt/P from 65±3 to 128±4 s-1 and isolength velocity from 72±4 to 120±7 mm/s without affecting LV end diastolic D significantly. Mean arterial P rose from 92±2 to 104±3 mm Hg and heart rate from 78±3 to 111±7 beats/min, while LV end systolic D fell from 24.1±1.4 to 19.9±1.8 mm, reflecting a rise in stroke volume from 30±4 to 42±3 ml. Cardiac output rose from 2.41±0.23 to 4.35±0.28 liter/min, while calculated total peripheral resistance declined from 0.042±0.005 to 0.028±0.003 mm Hg/ml/min. The greatest increases in flow and decreases in calculated resistance occurred in the iliac and coronary beds, and the least occurred in the renal bed. Propranolol blocked the inotropic and beta2 dilator responses while vasoconstricting effects mediated by alpha adrenergic stimulation remained in each of the beds studied. When dobutamine was infused after a combination of practolol and phentolamine, dilatation occurred in each of the beds studied. These observations indicate that dobutamine is a potent positive inotropic agent with relatively slight effects on preload, afterload, or heart rate, and thus may be a potentially useful clinical agent. The one property of this drug which is not ideal is its tendency to cause a redistribution of cardiac output favoring the muscular beds at the expense of the kidney and visceral beds. Images PMID:4825224

  20. Cardiac and pulmonary issues in LT assessment candidates.

    PubMed

    McAvoy, Norma C; Hayes, Peter C

    2014-08-01

    With the incidence of liver disease increasing worldwide, a growing number of patients are being referred for assessment for liver transplant (LT). Unfortunately, the donor pool is not expanding at the same rate, which consequentially results in increasing demand on a finite resource. It is therefore imperative that the candidate who undergoes an LT gets maximal benefit with a resultant maximal increase in life expectancy. This article addresses some of the main cardiac and pulmonary issues that may occur in LT assessment candidates. PMID:25017074

  1. Influence of heart motion on cardiac output estimation by means of electrical impedance tomography: a case study.

    PubMed

    Proença, Martin; Braun, Fabian; Rapin, Michael; Solà, Josep; Adler, Andy; Grychtol, Bart?omiej; Bohm, Stephan H; Lemay, Mathieu; Thiran, Jean-Philippe

    2015-06-01

    Electrical impedance tomography (EIT) is a non-invasive imaging technique that can measure cardiac-related intra-thoracic impedance changes. EIT-based cardiac output estimation relies on the assumption that the amplitude of the impedance change in the ventricular region is representative of stroke volume (SV). However, other factors such as heart motion can significantly affect this ventricular impedance change. In the present case study, a magnetic resonance imaging-based dynamic bio-impedance model fitting the morphology of a single male subject was built. Simulations were performed to evaluate the contribution of heart motion and its influence on EIT-based SV estimation. Myocardial deformation was found to be the main contributor to the ventricular impedance change (56%). However, motion-induced impedance changes showed a strong correlation (r = 0.978) with left ventricular volume. We explained this by the quasi-incompressibility of blood and myocardium. As a result, EIT achieved excellent accuracy in estimating a wide range of simulated SV values (error distribution of 0.57 ± 2.19 ml (1.02 ± 2.62%) and correlation of r = 0.996 after a two-point calibration was applied to convert impedance values to millilitres). As the model was based on one single subject, the strong correlation found between motion-induced changes and ventricular volume remains to be verified in larger datasets. PMID:26006113

  2. [Clinical practice guide for the management of low cardiac output syndrome in the postoperative period of heart surgery].

    PubMed

    Pérez Vela, J L; Martín Benítez, J C; Carrasco González, M; de la Cal López, M A; Hinojosa Pérez, R; Sagredo Meneses, V; del Nogal Saez, F

    2012-05-01

    The low cardiac output syndrome is a potential complication in cardiac surgery patients and associated with increased morbidity and mortality. This guide is to provide recommendations for the management of these patients, immediately after surgery, admitted to the ICU. The recommendations are grouped into different sections, trying to answer from the most basic concepts such as the definition to the different sections of basic and advanced monitoring and ending with the complex management of this syndrome. We propose an algorithm for initial management, as well as two other for ventricular failure (predominantly left or right). Most of the recommendations are based on expert consensus because of the lack of randomized trials of adequate design and sample size in this group of patients. The quality of evidence and strength of the recommendations were made following the GRADE methodology. The guide is presented as a list of recommendations (and level of evidence for each recommendation) for each question on the selected topic. Then for each question, we proceed to the justification of the recommendations. PMID:22445905

  3. Beta-adrenergic blockade affects initial drug distribution due to decreased cardiac output and altered blood flow distribution.

    PubMed

    Avram, Michael J; Krejcie, Tom C; Henthorn, Thomas K; Niemann, Claus U

    2004-11-01

    Beta-adrenergic receptor blockers decrease intravenous anesthetic dose requirements. The present study determined the effect of propranolol on indocyanine green and antipyrine disposition from the moment of rapid intravenous injection. Anti-pyrine is a physiological marker that distributes to a volume as large as total body water in a blood flow-dependent manner and is a pharmacokinetic surrogate for many lipophilic drugs, including intravenous anesthetics. Antipyrine and indocyanine green disposition were determined twice in five healthy adult males in this Institutional Review Board-approved study, once during propranolol infusion. After rapid indocyanine green and antipyrine injection, arterial blood samples were collected frequently for 2 min and less frequently thereafter. Plasma indocyanine green and antipyrine concentrations were measured by high-performance liquid chromatography. Indocyanine green and antipyrine disposition were characterized, using SAAM II, by a recirculatory pharmacokinetic model that describes drug disposition from the moment of injection. Parameters were compared using the paired t test. The disposition of indocyanine green demonstrated that propranolol decreased cardiac output at the expense of the fast peripheral (nonsplanchnic) intravascular circuit. The area under the antipyrine concentration versus time relationship was doubled for at least the first 3 min after injection due to both decreased cardiac output and maintenance of nondistributive blood flow at the expense of a two-thirds reduction of blood flow (intercompartmental clearance) to the rapidly equilibrating (fast, splanchnic) tissue volume. The increase in antipyrine area under the curve due to propranolol-induced alteration of initial antipyrine disposition could explain decreased intravenous anesthetic dose requirements in the presence of beta-adrenergic receptor blockade. PMID:15197245

  4. Engineered Cardiac Tissues for in vitro Assessment of Contractile Function and Repair Mechanisms

    Microsoft Academic Search

    Do Eun Kim; Eun Jung Lee; Timothy P. Martens; Rina Kara; Hina W. Chaudhry; Silviu Itescu; Kevin D. Costa

    2006-01-01

    For efficiently assessing the potential for grafted cells to repair infarcted myocardium, a simplified surrogate heart muscle system would offer numerous advantages. Using neonatal rat cardiac myocytes in a collagen matrix, we created thin cylindrical engineered cardiac tissues (ECTs) that exhibit essential aspects of physiologic cardiac muscle function. Furthermore, a novel cryo-injured ECT model of myocardial infarction offers the potential

  5. Non-invasive assessment of perioperative myocardial cell damage by circulating cardiac troponin T

    Microsoft Academic Search

    H A Katus; M Schoeppenthau; A Tanzeem; H G Bauer; W Saggau; K W Diederich; S Hagl; W Kuebler

    1991-01-01

    Troponin T is a unique cardiac antigen which is continuously released from infarcting myocardium. Its cardiospecificity as a marker protein might be particularly useful in assessing myocardial cell damage in patients undergoing cardiac surgery. Therefore, circulating troponin T was measured in serial blood samples from 56 patients undergoing cardiac surgery and in two control groups--22 patients undergoing minor orthopaedic surgery

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

    NASA Technical Reports Server (NTRS)

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

    1971-01-01

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

  7. Beat-by-beat analysis of cardiac output and blood pressure responses to short-term barostimulation in different body positions

    NASA Astrophysics Data System (ADS)

    Hildebrandt, Wulf; Schütze, Harald; Stegemann, J.

    Rapid quantification of the human baro-reflex control of heart rate has been achieved on a beat-by-beat basis using a neck-chamber with quick ECG-triggered pressure changes. Referring to recent findings on heart rate and stroke volume, the present study uses this technique to compare cardiac output as well as blood pressure changes in supine and upright position to investigate feedback effects and to confirm postural reflex modifications not revealed by RR-interval changes. A suction profile starting at +40 mmHg and running 7 steps of pressure decrease down to -65 mmHg was examined in 0° and 90° tilting position while beat-by-beat recordings were done of heart rate, stroke volume (impedance-cardiography) and blood pressure (Finapres tm) (n=16). The percentual heart rate decrease failed to be significantly different between positions. A suction-induced stroke volume increase led to a cardiac output almost maintained when supine and significantly increased when upright. A decrease in all blood pressure values was found during suction, except for systolic values in upright position which increased. Conclusively, (a) it is confirmed that different inotropy accounts for the seen gravitational effect on the cardiac output not represented by heart rate; (b) identical suction levels in different positions lead to different stimuli at the carotid receptor. This interference has to be considered in microgravity studies by beat-by-beat measurement of cardiac output and blood pressure.

  8. Comparison between mixed venous oxygen saturation and thermodilution cardiac output in monitoring patients with severe heart failure treated with milrinone and dobutamine

    Microsoft Academic Search

    Stefanie Nuñez; Alan Maisel

    1998-01-01

    Purpose Although thermodilution cardiac output (COtd) is the accepted method for monitoring patients with heart failure in the intensive care unit, it is particularly inaccurate in low-flow states and in the presence of tricuspid regurgitation; in addition, it does not adequately reflect the interaction between oxygen delivery and tissue oxygen extraction. We were concerned about the underuse of mixed venous

  9. Cardiac output monitoring in septic shock: evaluation of the third-generation Flotrac-Vigileo.

    PubMed

    Marqué, Sophie; Gros, Antoine; Chimot, Loic; Gacouin, Arnaud; Lavoué, Sylvain; Camus, Christophe; Le Tulzo, Yves

    2013-06-01

    Continuous cardiac index (CI) monitoring is frequently used in critically ill patients. Few studies have compared the pulse contour-based device FloTrac/Vigileo to pulmonary artery thermodilution (PAC) in terms of accuracy for CI monitoring in septic shock. The aim of our study was to compare the third-generation FloTrac/Vigileo to PAC in septic shock. Eighteen patients with septic shock requiring monitoring by PAC were included in this study. We monitored CI using both FloTrac/Vigileo and continuous thermodilution (PAC-CI). Hemodynamic data were recorded every hour or every 2 min during fluid challenges. The primary endpoint was the global agreement of all CI-paired measurements determined using the Bland-Altman method adapted to replicated data. We tested the linearity of the bias by regression analysis, and compared the reactivity of the 2 techniques during fluid challenges. A receiver operating characteristic (ROC) curve analysis tested the ability of FloTrac/Vigileo to detect concordant and significative CI changes, using PAC-CI as the reference method. Overall, 1,201 paired CI measurements were recorded. The Bland-Altman analysis for global agreement of the 2 techniques showed a bias of -0.1 ± 2.1 L min(-1) m(-2) and a percentage error of 64 %. The overall correlation coefficient between PAC-CI and FloTrac/Vigileo CI was 0.47 (p < 0.01), with r(2) = 0.22. The area under the curve of the ROC curve for detecting concordant and significant changes in CI was 0.72 (0.53; 0.87). In our study, third-generation Flowtrac-Vigileo appears to be too inaccurate to be recommended for CI monitoring in septic shock. PMID:23361128

  10. Quantitative method to assess economic output of climate change

    NASA Astrophysics Data System (ADS)

    jieming, C.

    2013-12-01

    In this paper, economic output of climate change is picked from the historical data, and a methodology of quantitative predicted economic output of climate change is provided by an economic-climatic model (C-D-C model). A historical reciprocating examination is engaged, using the data of outputs of various crops and total outputs of grain in 8 agricultural areas of China from 1981 to 2000, as well as the meteorological data of 160 observatory stations in China in the same time interval. The results show the methods are reasonable in certain extent and good in application. Finally, meaningful summery is concluded. The authors try to give a way for studying the effect of the future climatic change on economy. The results in economic research are introduced to the global climatic change study.

  11. Serotonin receptor blockade improves cardiac output and hypoxia in porcine ARDS.

    PubMed

    Sielaff, T D; Kellum, J M; Sugerman, H J; Kuemmerle, J F; Tatum, J L

    1987-08-01

    The effects of the serotonin receptor blocker, ketanserin, were studied in a porcine Pseudomonas adult respiratory distress syndrome model. Swine, weighing 14-30 kg, were anesthetized and ventilated with 0.5 FiO2 and 5 cm H2O positive end expiratory pressure. Three groups were studied: saline control (C, n = 9), continuous intravenous Pseudomonas aeruginosa, 5.0 X 10(8)CFU/kg/min (Ps, n = 8), and Pseudomonas and intravenous ketanserin, 0.2 mg/kg, given at 20 and 120 min after the onset of the Pseudomonas infusion (KET, n = 5). Pulmonary arterial (PAP) and systemic arterial (SAP) pressures, cardiac index (CI), thermal Cardio-Green extravascular lung water (EVLW), pulmonary albumin flux (slope index, SI), arterial blood gases, and whole blood serotonin levels were measured and pulmonary shunt and pulmonary (PVRI) and systemic (SVRI) vascular resistance indices were calculated. At 3 hr the Ps group demonstrated significant (P less than 0.05) increases in PAP (34 +/- 1 vs C 13 +/- 2 mm Hg), EVLW (14.4 +/- 2.2 vs C 4.3 +/- 1.2 ml/kg), SI (2.05 +/- 0.23 X 10(-3) vs C 0.38 +/- 0.09 X 10(-3) U/min), pulmonary shunt (67 +/- 15% vs C 9 +/- 3%), PVRI (1599 +/- 89 vs C 184 +/- 14 dyn X sec X cm-5/m2), and SVRI (4542 +/- 774 vs C 2087 +/- 129 dyn X sec X cm-5/m2) and decreases in CI (0.9 +/- 0.1 L/min/m2 vs C 2.8 +/- 0.2 L/min/m2), PaO2 (93 +/- 17 Torr vs C 203 +/- 15 Torr) and arterial blood serotonin concentration (23.5 +/- 13% decrease from basal). Treatment with ketanserin was associated with maintenance of PaO2 (KET 207 +/- 5 mm Hg vs C 203 +/- 15 mm Hg), pulmonary shunt (KET 8 +/- 3% vs C 9 +/- 3%), and CI (KET 2.3 +/- 0.1 L/min/m2 vs C 2.8 +/- 0.2 L/min/m2) at control levels and attenuated the Pseudomonas-induced increase in PVRI (873 +/- 37 vs Ps 1599 +/- 89 dyn X sec X cm-5/m2) and SVRI (2089 +/- 287 vs Ps 4542 +/- 774 dyn X sec X cm-5/m2), but did not alter the development of pulmonary edema. These data indicate that serotonin plays a role in the development of the V/Q mismatch and arterial hypoxemia observed in this model by a mechanism independent of changes in microvascular injury and permeability and was probably a result of reduced peripheral bronchiolar constriction. PMID:3626534

  12. How to assess prognosis after cardiac arrest and therapeutic hypothermia

    PubMed Central

    2014-01-01

    The prognosis of patients who are admitted in a comatose state following successful resuscitation after cardiac arrest remains uncertain. Although the introduction of therapeutic hypothermia (TH) and improvements in post-resuscitation care have significantly increased the number of patients who are discharged home with minimal brain damage, short-term assessment of neurological outcome remains a challenge. The need for early and accurate prognostic predictors is crucial, especially since sedation and TH may alter the neurological examination and delay the recovery of motor response for several days. The development of additional tools, including electrophysiological examinations (electroencephalography and somatosensory evoked potentials), neuroimaging and chemical biomarkers, may help to evaluate the extent of brain injury in these patients. Given the extensive literature existing on this topic and the confounding effects of TH on the strength of these tools in outcome prognostication after cardiac arrest, the aim of this narrative review is to provide a practical approach to post-anoxic brain injury when TH is used. We also discuss when and how these tools could be combined with the neurological examination in a multimodal approach to improve outcome prediction in this population. PMID:24417885

  13. Assessing thermalization and estimating the Hamiltonian with output data only

    SciTech Connect

    Rau, Jochen [Institut fuer Theoretische Physik, Johann Wolfgang Goethe-Universitaet, Max-von-Laue-Strasse 1, D-60438 Frankfurt am Main (Germany)

    2011-11-15

    I consider the generic situation where a finite number of identical test systems in varying (possibly unknown) initial states are subjected independently to the same unknown process. I show how one can infer from the output data alone whether the process in question induces thermalization and, if so, which constants of the motion characterize the final equilibrium states. In case thermalization does occur and there is no evidence for constants of the motion other than energy, I further show how the same output data can be used to estimate the test systems' effective Hamiltonian. For both inference tasks I devise a statistical framework inspired by the generic techniques of factor and principal component analysis. I illustrate its use in the simple example of qubits.

  14. Arterial pressure-based cardiac output monitoring: a multicenter validation of the third-generation software in septic patients

    PubMed Central

    Marx, Gernot; Tan, Andrew; Junker, Christopher; Van Nuffelen, Marc; Hüter, Lars; Ching, Willy; Michard, Frédéric; Vincent, Jean-Louis

    2010-01-01

    Purpose Second-generation FloTrac software has been shown to reliably measure cardiac output (CO) in cardiac surgical patients. However, concerns have been raised regarding its accuracy in vasoplegic states. The aim of the present multicenter study was to investigate the accuracy of the third-generation software in patients with sepsis, particularly when total systemic vascular resistance (TSVR) is low. Methods Fifty-eight septic patients were included in this prospective observational study in four university-affiliated ICUs. Reference CO was measured by bolus pulmonary thermodilution (iCO) using 3–5 cold saline boluses. Simultaneously, CO was computed from the arterial pressure curve recorded on a computer using the second-generation (COG2) and third-generation (COG3) FloTrac software. CO was also measured by semi-continuous pulmonary thermodilution (CCO). Results A total of 401 simultaneous measurements of iCO, COG2, COG3, and CCO were recorded. The mean (95%CI) biases between COG2 and iCO, COG3 and iCO, and CCO and iCO were ?10 (?15 to ?5)% [?0.8 (?1.1 to ?0.4) L/min], 0 (?4 to 4)% [0 (?0.3 to 0.3) L/min], and 9 (6–13)% [0.7 (0.5–1.0) L/min], respectively. The percentage errors were 29 (20–37)% for COG2, 30 (24–37)% for COG3, and 28 (22–34)% for CCO. The difference between iCO and COG2 was significantly correlated with TSVR (r2 = 0.37, p < 0.0001). A very weak (r2 = 0.05) relationship was also observed for the difference between iCO and COG3. Conclusions In patients with sepsis, the third-generation FloTrac software is more accurate, as precise, and less influenced by TSVR than the second-generation software. Electronic supplementary material The online version of this article (doi:10.1007/s00134-010-2098-8) contains supplementary material, which is available to authorized users. PMID:21153399

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

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

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

  16. Role of heart rate and stroke volume during muscle metaboreflex-induced cardiac output increase: differences between activation during and after exercise

    Microsoft Academic Search

    Antonio Crisafulli; Francesco Piras; Michele Filippi; Carlo Piredda; Paolo Chiappori; Franco Melis; Raffaele Milia; Filippo Tocco; Alberto Concu

    We hypothesized that the role of stroke volume (SV) in the metaboreflex-induced cardiac output (CO) increase was blunted when\\u000a the metaboreflex was stimulated by exercise muscle ischemia (EMI) compared with post-exercise muscle ischemia (PEMI), because\\u000a during EMI heart rate (HR) increases and limits diastolic filling. Twelve healthy volunteers were recruited and their hemodynamic\\u000a responses to the metaboreflex evoked by EMI,

  17. Estimation of cardiac output in a pharmacological trial using a simple method based on arterial blood pressure signal waveform: a comparison with pulmonary thermodilution and echocardiographic methods

    Microsoft Academic Search

    Jani Penttilä; Amir Snapir; Erkki Kentala; Juha Koskenvuo; Jussi Posti; Mika Scheinin; Harry Scheinin; Tom Kuusela

    2006-01-01

    Objective  Cardiac output (CO) has traditionally been measured using invasive techniques, which involve an element of risk. Thus, a reliable less-invasive method for determining CO would be very valuable for research use. We tested whether simple analysis of the arterial pulse waveform, not requiring large-vessel catheterisation or expensive equipment, could provide an estimate of CO that is accurate enough for pharmacological

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

    NASA Technical Reports Server (NTRS)

    Carnes, J. G.

    1978-01-01

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

  19. Non-invasive assessment of cardiac physiology by tissue Doppler echocardiography A comparison with invasive haemodynamics

    Microsoft Academic Search

    J. Zamorano; D. R. Wallbridge; J. Ge; J. Drozd; J. Nesser; R. Erbel

    Aim The purpose of this study was to determine the relationship of myocardial velocity patterns, as assessed by tissue Doppler echocardiography, to the contraction and relaxation phases of the cardiac cycle, as determined during cardiac catheterization. Methods Recordings of left ventricular\\/aortic and left ventricular\\/pulmonary wedge pressures were obtained sim- ultaneously with apical tissue Doppler echocardiographic images of the left ventricle.

  20. Cardiac 123I-MIBG scintigraphy can assess the disease severity and phenotype of PD

    Microsoft Academic Search

    Shinji Saiki; Genjiro Hirose; Koichiro Sakai; Satoshi Kataoka; Ariyuki Hori; Misuzu Saiki; Muichi Kaito; Kotaro Higashi; Suzuka Taki; Kazuo Kakeshita; Susumu Fujino; Miho Miaki

    2004-01-01

    Objective: Cardiac 123I-metaiodobenzylguanidine (MIBG) scintigraphy studies of patients with idiopathic Parkinson's disease (PD) found decreased uptake. Whether this decrease is associated with clinical severity as assessed by the Unified Parkinson's Disease Rating Scale (UPDRS) and the phenotypes of PD has not been determined. Methods: Cardiac MIBG scintigraphy was performed on 34 patients with PD, 7 with multiple system atrophy (MSA),

  1. Reduced heart rate and cardiac output differentially affect angiogenesis, growth, and development in early chicken embryos (Gallus domesticus).

    PubMed

    Branum, Sylvia R; Yamada-Fisher, Miho; Burggren, Warren

    2013-01-01

    An increase in both vascular circumferential tension and shear stress in the developing vasculature of the chicken embryo has been hypothesized to stimulate angiogenesis in the developing peripheral circulation chorioallantoic membrane (CAM). To test this hypothesis, angiogenesis in the CAM, development, and growth were measured in the early chicken embryo, following acute and chronic topical application of the purely bradycardic drug ZD7288. At hour 56, ZD7288 reduced heart rate (f(H)) by ~30% but had no significant effect on stroke volume (~0.19 ± 0.2 ?L), collectively resulting in a significant fall in cardiac output (CO) from ~27 ± 3 to 18 ± 2 ?L min(-1). Mean f(H) at 72 h of development was similarly significantly lowered by acute ZD7288 treatment (250 ?M) to 128 ± 0.3 beats min(-1), compared with 174.5 ± 0.3 and 174.7 ± 0.8 beats min(-1) in control and Pannett-Compton (P-C) saline-treated embryos, respectively. Chronic dosing with ZD7288-and the attendant decreases in f(H) and CO-did not change eye diameter or cervical flexion (key indicators of development rate) at 120 h but significantly reduced overall growth (wet and dry body mass decreased by 20%). CAM vessel density index (reflecting angiogenesis) measured 200-400 ?m from the umbilical stalk was not altered, but ZD7288 reduced vessel numbers-and therefore vessel density-by 13%-16% more distally (500-600 ?m from umbilical stalk) in the CAM. In the ZD7288-treated embryos, a decrease in vessel length was found within the second branch order (~300-400 ?m from the umbilical stock), while a decrease in vessel diameter was found closer to the umbilical stock, beginning in the first branch order (~200-300 ?m). Paradoxically, chronic application of P-C saline also reduced peripheral CAM vessel density index at 500 and 600 ?m by 13% and 7%, respectively, likely from washout of local angiogenic factors. In summary, decreased f(H) with reduced CO did not slow development rate but reduced embryonic growth rate and angiogenesis in the CAM periphery. This study demonstrates for the first time that different processes in the ontogeny of the early vertebrate embryo (i.e., hypertrophic growth vs. development) have differential sensitivities to altered convective blood flow. PMID:23629887

  2. Effects of head-up tilt on mean arterial pressure, heart rate, and regional cardiac output distribution in aging rats 

    E-print Network

    Ramsey, Michael Wiechmann

    2006-04-12

    Many senescent individuals demonstrate an inability to regulate mean arterial pressure (MAP) in response to standing or head-up tilt; however, whether this aging effect is the result of depressed cardiac function or an ...

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

    PubMed

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

    2013-04-01

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

  4. Assessment of Inlet Cooling to Enhance Output of a Fleet of Gas Turbines 

    E-print Network

    Wang, T.; Braquet, L.

    2008-01-01

    An analysis was made to assess the potential enhancement of a fleet of 14 small gas turbines' power output by employing an inlet air cooling scheme at a gas process plant. Various gas turbine (GT) inlet air cooling schemes were reviewed. The inlet...

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

    EPA Science Inventory

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

  6. Assessment of Inlet Cooling to Enhance Output of a Fleet of Gas Turbines

    E-print Network

    Wang, T.; Braquet, L.

    2008-01-01

    An analysis was made to assess the potential enhancement of a fleet of 14 small gas turbines' power output by employing an inlet air cooling scheme at a gas process plant. Various gas turbine (GT) inlet air cooling schemes were reviewed. The inlet...

  7. Continuously assessed right ventricular end-diastolic volume as a marker of cardiac preload and fluid responsiveness in mechanically ventilated cardiac surgical patients

    Microsoft Academic Search

    Christoph Wiesenack; Christoph Fiegl; Andreas Keyser; Sven Laule; Christopher Prasser; Cornelius Keyl

    2005-01-01

    Introduction  Assessing cardiac preload and fluid responsiveness accurately is important when attempting to avoid unnecessary volume replacement\\u000a in the critically ill patient, which is associated with increased morbidity and mortality. The present clinical trial was\\u000a designed to compare the reliability of continuous right ventricular end-diastolic volume (CEDV) index assessment based on\\u000a rapid response thermistor technique, cardiac filling pressures (central venous pressure

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

    PubMed

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

    2014-04-01

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

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

    PubMed

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

    2009-02-01

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

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

    PubMed Central

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

    2009-01-01

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

  11. [Summary of the consensus document: "Clinical practice guide for the management of low cardiac output syndrome in the postoperative period of heart surgery"].

    PubMed

    Pérez Vela, J L; Martín Benitez, J C; Carrasco Gonzalez, M; de la Cal López, M A; Hinojosa Pérez, R; Sagredo Meneses, V; del Nogal Saez, F

    2012-05-01

    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 trials of adequate design and sample size in patients of this kind. The quality of evidence and strength of the recommendations were based on the GRADE methodology. The guide is presented as a list of recommendations (with the level of evidence for each recommendation) for each question on the selected topic. For each question, justification of the recommendations is then provided. PMID:22445904

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

    SciTech Connect

    Kovacs, A., E-mail: Attila.Kovacs@ukb.uni-bonn.d [University of Bonn, Department of Radiology (Germany); Schepke, M.; Heller, J. [University of Bonn, Department of Internal Medicine I (Germany); Schild, H. H.; Flacke, S. [University of Bonn, Department of Radiology (Germany)

    2010-04-15

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

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

    SciTech Connect

    Cushman, R.M.

    1990-01-01

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

  14. Ultrasonography assessment of vocal cords mobility in children after cardiac surgery

    PubMed Central

    Shaath, Ghassan A.; Jijeh, Abdulraouf; Alkurdi, Ahmad; Ismail, Sameh; Elbarbary, Mahmoud; Kabbani, Mohamed S.

    2012-01-01

    Objectives Upper airway obstruction after pediatric cardiac surgery is not uncommon. In the cardiac surgical population, an important etiology is vocal cord paresis or paralysis following extubation. In this study, we aimed to evaluate the feasibility and accuracy of ultrasonography (US) assessment of the vocal cords mobility and compare it to fiber-optic laryngoscope (FL). Material and methods A prospective pilot study has been conducted in Pediatric Cardiac ICU (PCICU) at King Abdulaziz Cardiac Center (KACC) from the 1st of June 2009 till the end of July 2010. Patients who had cardiac surgery manifested with significant signs of upper airway obstruction were included. Each procedure was performed by different operators who were blinded to each other report. Results of invasive (FL) and non-invasive ultrasonography (US) investigations were compared. Results Ten patients developed persistent significant upper airway obstruction after cardiac surgery were included in the study. Their mean ± SEM of weight and age were 4.6 ± 0.4 kg and 126.4 ± 51.4 days, respectively. All patients were referred to bedside US screening for vocal cord mobility. The results of US were compared subsequently with FL findings. Results were identical in nine (90%) patients and partially different in one (10%). Six patients showed abnormal glottal movement while the other four patients demonstrated normal vocal cords mobility by FL. Sensitivity of US was 100% and specificity of 80%. Conclusion US assessment of vocal cord is simple, non-invasive and reliable tool to assess vocal cords mobility in the critical care settings. This screening tool requires skills that can be easily obtained. PMID:23960693

  15. In emergently ventilated trauma patients, low end-tidal CO2 and low cardiac output are associated and correlate with hemodynamic instability, hemorrhage, abnormal pupils, and death

    PubMed Central

    2013-01-01

    Background In a smaller experience, the authors previously demonstrated that end-tidal carbon dioxide (PetCO2) and cardiac output (CO) had a positive association in emergently intubated trauma patients during Emergency Department resuscitation. The aim of this larger study was to reassess the relationship of PetCO2 with CO and identify patient risk-conditions influencing PetCO2 and CO values. Methods The investigation consists of acutely injured trauma patients requiring emergency tracheal intubation. The study focuses on the prospective collection of PetCO2 and noninvasive CO monitor (NICOM®) values in the Emergency Department. Results From the end of March through August 2011, 73 patients had 318 pairs of PetCO2 (mm Hg) and CO (L/min.) values. Mean data included Injury Severity Score (ISS) ?15 in 65.2%, Glasgow Coma Score of 6.4?±?4.6, hypotension in 19.0%, and death in 34.3%. With PetCO2???25 (15.9?±?8.0), systolic blood pressure was 77.0?±?69, CO was 3.2?±?3.0, cardiac arrest was 60.4%, and mortality was 84.9%. During hypotension, CO was lower with major blood loss (1.9), than without major loss (5.0; P?=?0.0008). Low PetCO2 was associated with low CO (P??20, hypotension, bradycardia, major blood loss, abnormal pupils, cardiac arrest, and death. Low CO was associated (P???0.0059) with ISS?>?20, hypotension, bradycardia, major blood loss, abnormal pupils, cardiac arrest, and death. Conclusions During emergency department resuscitation, a decline in PetCO2 correlates with decreases in noninvasive CO in emergently intubated trauma patients. Decreasing PetCO2 and declining NICOM CO are associated with hemodynamic instability, hemorrhage, abnormal pupils, and death. The study indicates that NICOM CO values are clinically discriminate and have physiologic validity. PMID:24020798

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

    PubMed Central

    2014-01-01

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

  17. Reliability of myocardial salvage assessment by cardiac magnetic resonance imaging in acute reperfused myocardial infarction

    Microsoft Academic Search

    Steffen DeschHubertus; Hubertus Engelhardt; Josefine Meissner; Ingo Eitel; Mahdi Sareban; Georg Fuernau; Suzanne de Waha; Matthias Grothoff; Matthias Gutberlet; Gerhard Schuler; Holger Thiele

    Myocardial salvage assessed by cardiac magnetic resonance imaging (CMRI) holds promise as a surrogate endpoint in studies\\u000a comparing different treatment strategies for ST-elevation myocardial infarction (STEMI). The aim of this study was to evaluate\\u000a the reliability of salvaged myocardium measurements by CMRI. Twenty patients underwent CMRI on 2 consecutive days early after\\u000a reperfused STEMI to assess the area at risk

  18. Cardiac risk assessment: matching intensity of therapy to risk.

    PubMed

    Vesely, Mark R; Kelemen, Mark D

    2006-02-01

    Simple RSS allow for rapid decision making in the emergency department. The data presented in this article suggest that for patients at the highest risk and the lowest risk for complications of NSTEACS, the scoring systems work well and allow effective triage and treatment. For patients at intermediate risk (30%-40% of all patients who have ACS), however, it is not clear whether early aggressive treatment with cardiac catheterization or routine conservative management should be the standard of care. The consensus guidelines are vague, and the scoring systems discriminate less well for these patients. The authors think that patients at intermediate risk are best served by initial screening with an RSS like the TRS (with risk scores of 3-4), followed by a multimarker strategy to define risk better. They also think that the next step is to design clinical trials to test strategies of care defined prospectively by risk. This step would, in the authors' opinion, begin the next round of the cycle of clinical therapeutics [31]. The treatment of patients who have NSTE ACS has been characterized in the past 2 decades by care based on evidence from many excellent clinical tri-als. The consensus panels have convened and guide patient management. Quality-improvement initiatives such as CRUSADE and GRACE give feedback to improve compliance with guidelines. The understanding of risk is developing with the help of these scoring systems. Discovery is ongoing. The next decade of acute cardiac care will focus on early identification of patients at high risk and on matching the most intensive treatments to the patients most in need. Excessive testing and care promotes cost inefficiency and, perhaps, increased hazard for some patients. New trials are needed to move these new hypotheses back into practice. PMID:16326257

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

    SciTech Connect

    Melon, P.G.; Boyd, C.J.; McVey, S. [Univ. of Michigan Medical Center, Ann Arbor, MI (United States)]|[Univ. of Michigan, Ann Arbor, MI (United States)] [and others

    1997-03-01

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

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

    NASA Technical Reports Server (NTRS)

    Shykoff, Barbara E.; Swanson, Harvey T.

    1987-01-01

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

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

    EPA Science Inventory

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

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

    PubMed Central

    2003-01-01

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

  3. Cardiac output monitoring to guide fluid replacement in head and neck microvascular free flap surgery-what is current practice in the UK?

    PubMed

    Chalmers, Alison; Turner, Matthew W H; Anand, Rajiv; Puxeddu, Roberto; Brennan, Peter A

    2012-09-01

    Appropriate fluid balance is an important factor in the survival of free flaps, and recently there has been a shift towards more conservative fluid regimens. Several surgical specialties have made extensive use of the relatively non-invasive method of measuring cardiac output (CO) to optimise fluid balance during and after surgery, which has resulted in a shorter hospital stay, but little has been published in head and neck surgery. To ascertain its use in the head and neck we sent a postal questionnaire to the anaesthetic departments of 40 major head and neck units identified from the 2010 database of the British Association of Oral and Maxillofacial Surgeons (BAOMS). Questions were asked about the number of free flaps done in the unit each year, the monitoring of central venous and arterial blood pressure (and inotrope protocols), optimal target variables, and whether CO was monitored (with type of device). Thirty-two units responded (80%). While 26 units (81%) routinely monitored central venous pressure (CVP), CO was monitored in only 3 units (9%). There was a wide range of responses in relation to optimal variables and use of inotropes. As with other specialties, it is likely that CO monitoring will become widely used in head and neck reconstructive surgery. Not only does it enhance fluid optimisation, but it may also reduce hospital stay and morbidity. Appropriate clinical studies are urgently needed to evaluate its use in our specialty. PMID:21940078

  4. Stroke volume variations for assessment of cardiac responsiveness to volume loading in mechanically ventilated patients after cardiac surgery

    Microsoft Academic Search

    Daniel A. Reuter; Thomas W. Felbinger; Christian Schmidt; Erich Kilger; Oliver Goedje; Peter Lamm; Alwin E. Goetz

    2002-01-01

    Objective: We hypothesized that measuring stroke volume variation (SVV) during mechanical ventilation by continuous arterial pulse contour analysis allows the accurate prediction and monitoring of changes in cardiac index (CI) in response to volume administration. Design and setting: Prospective study in an university hospital. Patients: Twenty mechanically ventilated patients following cardiac surgery. Interventions: Volume loading with oxypolygelatin (3.5%) 20 ml

  5. Noninvasive Physiologic Assessment of Coronary Stenoses Using Cardiac CT

    PubMed Central

    Fan, Zhanming

    2015-01-01

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

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

    NASA Technical Reports Server (NTRS)

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

    2010-01-01

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

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

    PubMed Central

    Kochar, Minisha

    2013-01-01

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

  8. An Optimized and Simplified System of Mouse Embryonic Stem Cell Cardiac Differentiation for the Assessment of Differentiation Modifiers

    PubMed Central

    Hartman, Matthew E.; Librande, Jason R.; Medvedev, Ivan O.; Ahmad, Rabiah N.; Moussavi-Harami, Farid; Gupta, Pritha P.; Chien, Wei-Ming; Chin, Michael T.

    2014-01-01

    Generating cardiomyocytes from embryonic stem cells is an important technique for understanding cardiovascular development, the origins of cardiovascular diseases and also for providing potential reagents for cardiac repair. Numerous methods have been published but often are technically challenging, complex, and are not easily adapted to assessment of specific gene contributions to cardiac myocyte differentiation. Here we report the development of an optimized protocol to induce the differentiation of mouse embryonic stem cells to cardiac myocytes that is simplified and easily adapted for genetic studies. Specifically, we made four critical findings that distinguish our protocol: 1) mouse embryonic stem cells cultured in media containing CHIR99021 and PD0325901 to maintain pluripotency will efficiently form embryoid bodies containing precardiac mesoderm when cultured in these factors at a reduced dosage, 2) low serum conditions promote cardiomyocyte differentiation and can be used in place of commercially prepared StemPro nutrient supplement, 3) the Wnt inhibitor Dkk-1 is dispensable for efficient cardiac differentiation and 4) tracking differentiation efficiency may be done with surface expression of PDGFR? alone. In addition, cardiac mesodermal precursors generated by this system can undergo lentiviral infection to manipulate the expression of specific target molecules to assess effects on cardiac myocyte differentiation and maturation. Using this approach, we assessed the effects of CHF1/Hey2 on cardiac myocyte differentiation, using both gain and loss of function. Overexpression of CHF1/Hey2 at the cardiac mesoderm stage had no apparent effect on cardiac differentiation, while knockdown of CHF1/Hey2 resulted in increased expression of atrial natriuretic factor and connexin 43, suggesting an alteration in the phenotype of the cardiomyocytes. In summary we have generated a detailed and simplified protocol for generating cardiomyocytes from mES cells that is optimized for investigating factors that affect cardiac differentiation. PMID:24667642

  9. Non-invasive assessment of perioperative myocardial cell damage by circulating cardiac troponin T.

    PubMed Central

    Katus, H. A.; Schoeppenthau, M.; Tanzeem, A.; Bauer, H. G.; Saggau, W.; Diederich, K. W.; Hagl, S.; Kuebler, W.

    1991-01-01

    Troponin T is a unique cardiac antigen which is continuously released from infarcting myocardium. Its cardiospecificity as a marker protein might be particularly useful in assessing myocardial cell damage in patients undergoing cardiac surgery. Therefore, circulating troponin T was measured in serial blood samples from 56 patients undergoing cardiac surgery and in two control groups--22 patients undergoing minor orthopaedic surgery and 12 patients undergoing lung surgery by median sternotomy. In both control groups no troponin T could be detected, whereas activities of creatine kinase were raised in all 12 lung surgery controls and activities of the MB isoenzyme were raised in five of the 12 patients in the lung surgery group and in four of the 22 patients in the orthopaedic surgery group, respectively. All the patients undergoing coronary artery bypass grafting (n = 47) and cardiac surgery for other reasons (n = 9) had detectable concentrations of troponin T. Five patients had perioperative myocardial infarction detected as new Q waves and R wave reductions. In these five patients troponin T release persisted and serum concentrations (5.5-23 micrograms/l) reached a peak on the fourth postoperative day. In the 51 patients without perioperative myocardial infarction serum concentrations and the release kinetics of troponin T depended on the duration of cardiac arrest. In patients in whom aortic cross clamping was short troponin T increased slightly on the first postoperative days; in patients with longer periods of aortic cross clamping troponin T concentrations were higher and remained so beyond the fifth postoperative day. In patients with non-specific changes on the electrocardiogram troponin T concentrations were significantly higher on days 1 and 4 after operation than in patients with normal postoperative electrocardiograms(11.2 (5) and 4.5 (2.6) v 8.2 (3.4) and 2.9 (1.6) 1microg/l). Serum concentrations of troponin T showed some myocardial cell damage in every patient undergoing cardiac surgery. The persistent increases that were more common in patients with longer periods of cardiac arrest must have been caused by damage to the contractile apparatus. These results suggest that perioperative myocardial cell necrosis may be more common than indicated by changes of the QRS complex on the electrocardiogram. PMID:2039670

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

    SciTech Connect

    King, Martin; Giger, Maryellen L.; Suzuki, Kenji; Bardo, Dianna M. E.; Greenberg, Brent; Lan Li; Pan Xiaochuan [Department of Radiology, Committee on Medical Physics, University of Chicago, Chicago, Illinois 60637 (United States)

    2007-12-15

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

  11. Indium-111 antimyosin scintigraphy to assess myocardial damage in patients with suspected myocarditis and cardiac rejection

    SciTech Connect

    Carrio, I.; Berna, L.; Ballester, M.; Estorch, M.; Obrador, D.; Cladellas, M.; Abadal, L.; Ginjaume, M.

    1988-12-01

    Indium-111 antimyosin scans were used to assess myocardial damage in patients with suspected myocarditis and cardiac transplant rejection. The calculation of a myocardium to lung ratio (AM index) to quantify antimyosin uptake was performed. AM index in normal subjects (n = 8) at 48 hr postinjection was 1.46 +/- 0.04. In patients with suspected myocarditis (16 studies in 13 patients), AM index was 2.0 +/- 0.5 (p less than 0.001); suggesting a considerable incidence of ongoing cell damage in this group, despite the small proportion of positive right ventricular endomyocardial biopsy (RVbx) (4/13). In patients studied after cardiac transplantation (37 studies in 17 patients), AM indexes correlated with RVbx. In patients with RVbx proven rejection (n = 14), AM index was 1.87 +/- 0.19 (p less than 0.001). In patients with RVbx showing infiltrates but not myocyte damage (n = 13), AM index was 1.80 +/- 0.27 (p = 0.02). In patients with normal RVbx (n = 10), AM index was 1.56 +/- 0.17 (p = NS versus controls; p = 0.001 versus those with positive RVbx). Calculated AM indexes correlated with graded visual analysis of the scans (r = 0.823; p = 0.001). Antimyosin scans are an appropriate method to assess myocardial damage in patients with suspected myocarditis and cardiac rejection.

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

    PubMed Central

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

    2013-01-01

    Introduction. Nexfin (Bmeye, Amsterdam, Netherlands) is a noninvasive cardiac output (CO) monitor based on finger arterial pulse contour analysis. The aim of this study was to validate Nexfin CO (NexCO) against thermodilution (TDCO) and pulse contour CO (CCO) by PiCCO (Pulsion Medical Systems, Munich, Germany). Patients and Methods. In a mix of critically ill patients (n = 45), NexCO and CCO were measured continuously and recorded at 2-hour intervals during the 8-hour study period. TDCO was measured at 0–4–8?hrs. Results. NexCO showed a moderate to good (significant) correlation with TDCO (R2 0.68, P < 0.001) and CCO (R2 0.71, P < 0.001). Bland and Altman analysis comparing NexCO with TDCO revealed a bias (± limits of agreement, LA) of 0.4 ± 2.32?L/min (with 36% error) while analysis comparing NexCO with CCO showed a bias (±LA) of 0.2 ± 2.32?L/min (37% error). NexCO is able to follow changes in TDCO and CCO during the same time interval (level of concordance 89.3% and 81%). Finally, polar plot analysis showed that trending capabilities were acceptable when changes in NexCO (?NexCO) were compared to ?TDCO and ?CCO (resp., 89% and 88.9% of changes were within the level of 10% limits of agreement). Conclusion. we found a moderate to good correlation between CO measurements obtained with Nexfin and PiCCO. PMID:24319373

  13. Memory for Remembered Events: An Assessment of Output Monitoring in Free Recall

    ERIC Educational Resources Information Center

    Gardiner, John M.; Klee, Hilary

    1976-01-01

    A study is reported describing an output-monitoring phenomenon in free recall and establishing that subjects have accurate knowledge concerning their previous output performance. Implications with respect to other known memory phenomena are discussed. (Author/RM)

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

    PubMed Central

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

    2014-01-01

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

  15. Economic input-output life-cycle assessment of trade between Canada and the United States.

    PubMed

    Norman, Jonathan; Charpentier, Alex D; MacLean, Heather L

    2007-03-01

    With increasing trade liberalization, attempts at accounting for environmental impacts and energy use across the manufacturing supply chain are complicated by the predominance of internationally supplied resources and products. This is particularly true for Canada and the United States, the world's largest trading partners. We use an economic input-output life-cycle assessment (EIO-LCA) technique to estimate the economy-wide energy intensity and greenhouse gas (GHG) emissions intensity for 45 manufacturing and resource sectors in Canada and the United States. Overall, we find that U.S. manufacturing and resource industries are about 1.15 times as energy-intensive and 1.3 times as GHG-intensive as Canadian industries, with significant sector-specific discrepancies in energy and GHG intensity. This trend is mainly due to a greater direct reliance on fossil fuels for many U.S. industries, in addition to a highly fossil-fuel based electricity mix in the U.S. To account for these differences, we develop a 76 sector binational EIO-LCA model that implicitly considers trade in goods between Canada and the U.S. Our findings show that accounting for trade can significantly alter the results of life-cycle assessment studies, particularly for many Canadian manufacturing sectors, and the production/consumption of goods in one country often exerts significant energy- and GHG-influences on the other. PMID:17396636

  16. Magnetic resonance assessment of left ventricular diastolic dysfunction for detecting cardiac allograft vasculopathy in recipients of heart transplants

    Microsoft Academic Search

    Haruhiko Machida; Shinichi Nunoda; Kiyotaka Okajima; Kazunobu Shitakura; Akihiko Sekikawa; Yutaka Kubo; Kuniaki Otsuka; Masami Hirata; Shinya Kojima; Eiko Ueno

    Cardiac allograft vasculopathy (CAV) is a major late complication in heart transplant recipients, graded based on intravascular\\u000a ultrasound (IVUS), and accelerates left ventricular (LV) diastolic dysfunction. We investigated the clinical feasibility of\\u000a using magnetic resonance (MR) to assess LV diastolic dysfunction noninvasively in transplant recipients. Thirty-eight asymptomatic\\u000a recipients (25 men, 37.2 ± 14.9 years) underwent both IVUS and cardiac MR. Based on IVUS,

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

    NASA Astrophysics Data System (ADS)

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

    2015-04-01

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

  18. Can endotracheal bioimpedance cardiography assess hemodynamic response to passive leg raising following cardiac surgery?

    PubMed Central

    2012-01-01

    Background The utility of endotracheal bioimpedance cardiography (ECOM) has been scarcely reported. We tested the hypothesis that it could be an alternative to pulse contour analysis for cardiac index measurement and prediction in fluid responsiveness. Methods Twenty-five consecutive adult patients admitted to the intensive care unit following conventional cardiac surgery were prospectively included and investigated at baseline, during passive leg raising, and after fluid challenge. Comparative cardiac index data points were collected from pulse contour analysis (CIPC) and ECOM (CIECOM). Correlations were determined by linear regression. Bland-Altman analysis was used to compare the bias, precision, and limits of agreement. Percentage error was calculated. Changes in CIPC (?CIPC) and CIECOM (?CIECOM) during passive leg raising were collected to assess their discrimination in predicting fluid responsiveness. Results A significant relationship was found between CIPC and CIECOM (r?=?0.45; P?cardiac index continuously and could help to predict fluid responsiveness by using passive leg raising. PMID:22784815

  19. In vivo assessment of cardiac metabolism and function in the abdominal aortic banding model of compensated cardiac hypertrophy

    PubMed Central

    Ball, Vicky; Miller, Jack J.; Clarke, Kieran; Carr, Carolyn A.; Tyler, Damian J.

    2015-01-01

    Aims Left ventricular hypertrophy is an adaptive response of the heart to chronic mechanical overload and can lead to functional deterioration and heart failure. Changes in cardiac energy metabolism are considered as key to the hypertrophic remodelling process. The concurrence of obesity and hypertrophy has been associated with contractile dysfunction, and this work therefore aimed to investigate the in vivo structural, functional, and metabolic remodelling that occurs in the hypertrophied heart in the setting of a high-fat, high-sucrose, Western diet (WD). Methods and results Following induction of cardiac hypertrophy through abdominal aortic banding, male Sprague Dawley rats were exposed to either a standard diet or a WD (containing 45% fat and 16% sucrose) for up to 14 weeks. Cardiac structural and functional characteristics were determined by CINE MRI, and in vivo metabolism was investigated using hyperpolarized 13C-labelled pyruvate. Cardiac hypertrophy was observed at all time points, irrespective of dietary manipulation, with no evidence of cardiac dysfunction. Pyruvate dehydrogenase flux was unchanged in the hypertrophied animals at any time point, but increased incorporation of the 13C label into lactate was observed by 9 weeks and maintained at 14 weeks, indicative of enhanced glycolysis. Conclusion Hypertrophied hearts revealed little evidence of a switch towards increased glucose oxidation but rather an uncoupling of glycolytic metabolism from glucose oxidation. This was maintained under conditions of dietary stress provided by a WD but, at this compensated phase of hypertrophy, did not result in any contractile dysfunction. PMID:25750189

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

    PubMed

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

    2014-10-01

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

  1. Cardiac Oxidative Stress Is Elevated at the Onset of Dilated Cardiomyopathy in Streptozotocin-Diabetic Rats

    Microsoft Academic Search

    María J. Crespo; Joaquin Zalacaín; Donald C. Dunbar; Nildris Cruz; Lucy Arocho

    2008-01-01

    The association between nitric oxide synthase (eNOS and iNOS) status, oxidative stress, and cardiac function was evaluated in streptozotocin (STZ)-diabetic rats to understand the etiology of diabetic cardiomyopathy. Cardiac function was determined by echocardiography. eNOS and iNOS status and superoxide production were assessed by immunohistochemistry and chemiluminescence, respectively. In STZ-diabetic rats, stroke volume, cardiac output, and left ventricular ejection fraction

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

    SciTech Connect

    Lee, Chih-Jie; Kupinski, Matthew A.; Volokh, Lana [College of Optical Sciences, University of Arizona, Tucson, Arizona 85721 (United States); GE Healthcare, Haifa 39120 (Israel)

    2013-01-15

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

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

    PubMed

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

    2012-01-17

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

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

    NASA Astrophysics Data System (ADS)

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

    2001-09-01

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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  6. SPATIAL DOWNSCALING OF GLOBAL CLIMATE MODEL OUTPUT FOR SITE-SPECIFIC ASSESSMENT OF CROP PRODUCTION AND SOIL EROSION

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

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

    NASA Astrophysics Data System (ADS)

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

    1993-09-01

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

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

    ERIC Educational Resources Information Center

    Wamala, Robert; Ssembatya, Vincent A.

    2015-01-01

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

  9. Continuously assessed right ventricular end-diastolic volume as a marker of cardiac preload and fluid responsiveness in mechanically ventilated cardiac surgical patients

    PubMed Central

    Wiesenack, Christoph; Fiegl, Christoph; Keyser, Andreas; Laule, Sven; Prasser, Christopher; Keyl, Cornelius

    2005-01-01

    Introduction Assessing cardiac preload and fluid responsiveness accurately is important when attempting to avoid unnecessary volume replacement in the critically ill patient, which is associated with increased morbidity and mortality. The present clinical trial was designed to compare the reliability of continuous right ventricular end-diastolic volume (CEDV) index assessment based on rapid response thermistor technique, cardiac filling pressures (central venous pressure [CVP] and pulmonary capillary wedge pressure [PCWP]), and transesophageal echocardiographically derived evaluation of left ventricular end-diastolic area (LVEDA) index in predicting the hemodynamic response to volume replacement. Methods We studied 21 patients undergoing elective coronary artery bypass grafting. After induction of anesthesia, hemodynamic parameters were measured simultaneously before (T1) and 12 min after volume replacement (T2) by infusion of 6% hydroxyethyl starch 200/0.5 (7 ml/kg) at a rate of 1 ml/kg per min. Results The volume-induced increase in thermodilution-derived stroke volume index (SVITD) was 10% or greater in 19 patients and under 10% in two. There was a significant correlation between changes in CEDV index and changes in SVITD (r2 = 0.55; P < 0.01), but there were no significant correlations between changes in CVP, PCWP and LVEDA index, and changes in SVITD. The only variable apparently indicating fluid responsiveness was LVEDA index, the baseline value of which was weakly correlated with percentage change in SVITD (r2 = 0.38; P < 0.01). Conclusion An increased cardiac preload is more reliably reflected by CEDV index than by CVP, PCWP, or LVEDA index in this setting of preoperative cardiac surgery, but CEDV index did not reflect fluid responsiveness. The response of SVITD following fluid administration was better predicted by LVEDA index than by CEDV index, CVP, or PCWP. PMID:15987394

  10. Assessing Bacterial Invasion of Cardiac Cells in Culture and Heart Colonization in Infected Mice Using Listeria monocytogenes.

    PubMed

    McMullen, P David; Freitag, Nancy E

    2015-01-01

    Listeria monocytogenes is a Gram-positive facultative intracellular pathogen that is capable of causing serious invasive infections in immunocompromised patients, the elderly, and pregnant women. The most common manifestations of listeriosis in humans include meningitis, encephalitis, and fetal abortion. A significant but much less documented sequelae of invasive L. monocytogenes infection involves the heart. The death rate from cardiac illness can be up to 35% despite treatment, however very little is known regarding L. monocytogenes colonization of cardiac tissue and its resultant pathologies. In addition, it has recently become apparent that subpopulations of L. monocytogenes have an enhanced capacity to invade and grow within cardiac tissue. This protocol describes in detail in vitro and in vivo methods that can be used for assessing cardiotropism of L. monocytogenes isolates. Methods are presented for the infection of H9c2 rat cardiac myoblasts in tissue culture as well as for the determination of bacterial colonization of the hearts of infected mice. These methods are useful not only for identifying strains with the potential to colonize cardiac tissue in infected animals, but may also facilitate the identification of bacterial gene products that serve to enhance cardiac cell invasion and/or drive changes in heart pathology. These methods also provide for the direct comparison of cardiotropism between multiple L. monocytogenes strains. PMID:26065439

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

    PubMed

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

    2013-12-01

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

  12. Revision of the Dutch clinical algorithm for assessing patient needs in cardiac rehabilitation based on identified implementation problems

    Microsoft Academic Search

    Mariëtte M van Engen-Verheul; Hareld MC Kemps; Nicolette F de Keizer; Irene M Hellemans; Rick Goud; Roderik A Kraaijenhagen; Niels Peek

    2012-01-01

    Background: Despite all available evidence of its effectiveness, cardiac rehabilitation and secondary prevention (CRSP) is still insufficiently implemented in current clinical practice. Based on an analysis of implementation problems, recently the Dutch clinical algorithm for the assessment of patient’s CRSP needs was revised. The purpose of this paper is to describe the revision process and its results to improve CRSP

  13. Considerations for assessing the potential effects of antidiabetes drugs on cardiac ventricular repolarization: A report from the Cardiac Safety Research Consortium.

    PubMed

    Heller, Simon; Darpö, Börje; Mitchell, Malcolm I; Linnebjerg, Helle; Leishman, Derek J; Mehrotra, Nitin; Zhu, Hao; Koerner, John; Fiszman, Mónica L; Balakrishnan, Suchitra; Xiao, Shen; Todaro, Thomas G; Hensley, Ingrid; Guth, Brian D; Michelson, Eric L; Sager, Philip

    2015-07-01

    Thorough QT studies conducted according to the International Council on Harmonisation E14 guideline are required for new nonantiarrhythmic drugs to assess the potential to prolong ventricular repolarization. Special considerations may be needed for conducting such studies with antidiabetes drugs as changes in blood glucose and other physiologic parameters affected by antidiabetes drugs may prolong the QT interval and thus confound QT/corrected QT assessments. This review discusses potential mechanisms for QT/corrected QT interval prolongation with antidiabetes drugs and offers practical considerations for assessing antidiabetes drugs in thorough QT studies. This article represents collaborative discussions among key stakeholders from academia, industry, and regulatory agencies participating in the Cardiac Safety Research Consortium. It does not represent regulatory policy. PMID:26093861

  14. MIQuant – Semi-Automation of Infarct Size Assessment in Models of Cardiac Ischemic Injury

    PubMed Central

    Esteves, Tiago; de Pina, Maria de Fátima; Guedes, Joana G.; Freire, Ana; Quelhas, Pedro; Pinto-do-Ó, Perpétua

    2011-01-01

    Background The cardiac regenerative potential of newly developed therapies is traditionally evaluated in rodent models of surgically induced myocardial ischemia. A generally accepted key parameter for determining the success of the applied therapy is the infarct size. Although regarded as a gold standard method for infarct size estimation in heart ischemia, histological planimetry is time-consuming and highly variable amongst studies. The purpose of this work is to contribute towards the standardization and simplification of infarct size assessment by providing free access to a novel semi-automated software tool. The acronym MIQuant was attributed to this application. Methodology/Principal Findings Mice were subject to permanent coronary artery ligation and the size of chronic infarcts was estimated by area and midline-length methods using manual planimetry and with MIQuant. Repeatability and reproducibility of MIQuant scores were verified. The validation showed high correlation (rmidline length?=?0.981; rarea?=?0.970 ) and agreement (Bland-Altman analysis), free from bias for midline length and negligible bias of 1.21% to 3.72% for area quantification. Further analysis demonstrated that MIQuant reduced by 4.5-fold the time spent on the analysis and, importantly, MIQuant effectiveness is independent of user proficiency. The results indicate that MIQuant can be regarded as a better alternative to manual measurement. Conclusions We conclude that MIQuant is a reliable and an easy-to-use software for infarct size quantification. The widespread use of MIQuant will contribute towards the standardization of infarct size assessment across studies and, therefore, to the systematization of the evaluation of cardiac regenerative potential of emerging therapies. PMID:21980376

  15. Neural network uncertainty assessment using Bayesian statistics with application to remote sensing: 2. Output errors

    Microsoft Academic Search

    F. Aires; C. Prigent; W. B. Rossow

    2004-01-01

    A technique to estimate the uncertainties of the parameters of a neural network model, i.e., the synaptic weights, was described in the work of Aires [2004]. Using these weight uncertainty estimates, we compute the uncertainties in the network outputs (i.e., error bars and correlation structure of these errors). Such quantities are very important for evaluating any application of the neural

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

    ERIC Educational Resources Information Center

    Houck, Eric A.; Eom, Moonyoung

    2012-01-01

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

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

    PubMed Central

    2011-01-01

    Background There is variation in cardiac catheterization utilization across jurisdictions. Previous work from Alberta, Canada, showed no evidence of a plateau in the yield of high-risk disease at cardiac catheterization rates as high as 600 per 100,000 population suggesting that the optimal rate is higher. This work aims 1) To determine if a previously demonstrated linear relationship between the yield of high-risk coronary disease and cardiac catheterization rates persists with contemporary data and 2) to explore whether the linear relationship exists in other jurisdictions. Methods Detailed clinical information on all patients undergoing cardiac catheterization in 3 Canadian provinces was available through the Alberta Provincial Project for Outcomes Assessment in Coronary Heart (APPROACH) disease and partner initiatives in British Columbia and Nova Scotia. Population rates of catheterization and high-risk coronary disease detection for each health region in these three provinces, and age-adjusted rates produced using direct standardization. A mixed effects regression analysis was performed to assess the relationship between catheterization rate and high-risk coronary disease detection. Results In the contemporary Alberta data, we found a linear relationship between the population catheterization rate and the high-risk yield. Although the yield was slightly less in time period 2 (2002-2006) than in time period 1(1995-2001), there was no statistical evidence of a plateau. The linear relationship between catheterization rate and high-risk yield was similarly demonstrated in British Columbia and Nova Scotia and appears to extend, without a plateau in yield, to rates over 800 procedures per 100,000 population. Conclusions Our study demonstrates a consistent finding, over time and across jurisdictions, of linearly increasing detection of high-risk CAD as population rates of cardiac catheterization increase. This internationally-relevant finding can inform country-level planning of invasive cardiac care services. PMID:22115358

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

    NASA Technical Reports Server (NTRS)

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

    2013-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2015-05-01

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

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

    PubMed Central

    Valachis, Antonis; Nilsson, Cecilia

    2015-01-01

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

  1. Assessing contributory risk using economic input-output life-cycle analysis.

    PubMed

    Miller, Ian; Shelly, Michael; Jonmaire, Paul; Lee, Richard V; Harbison, Raymond D

    2005-04-01

    The contribution of consumer purchases of non-essential products to environmental pollution is characterized. Purchase decisions by consumers induce a complex sequence of economy-wide production interactions that influence the production and consumption of chemicals and subsequent exposure and possible public health risks. An economic input-output life-cycle analysis (EIO-LCA) was used to link resource consumption and production by manufacturers to corresponding environmental impacts. Using the US Department of Commerce's input-output tables together with the US Environmental Protection Agency's Toxics Release Inventory and AIRData databases, the economy-wide air discharges resulting from purchases of household appliances, motor homes, and games and toys were quantified. The economic and environmental impacts generated from a hypothetical 10,000 US dollar purchase for selected consumer items were estimated. The analysis shows how purchases of seemingly benign consumer products increase the output of air pollutants along the supply chain and contribute to the potential risks associated with environmental chemical exposures to both consumers and non-consumers alike. PMID:16026022

  2. Assessment of catchment scale connectivity in different catchments using measured suspended sediment output

    NASA Astrophysics Data System (ADS)

    Masselink, Rens; Keesstra, Saskia; Seeger, Manuel

    2014-05-01

    Recent developments in hydrology and geomorphology include the connectivity principle, which describes how different elements in a landscape are connected and how water and matter moves between these elements. So far, studies on connectivity have been mainly of a conceptual nature and have been done on a small scale, while studies that map, quantitatively establish relations, and model water and sediment transport in connectivity are rare. In this study we established a relation between change in connectivity within four catchments and the time of year by using suspended sediment data. The data were collected for four catchments in Navarra, Spain of which two catchments are dominated by forest and pasture, while the other two catchments are dominated by agriculture and have no forest. Data were collected during a 13 year period; 4 samples were taken a day at 6 hour intervals which were mixed to obtain a daily average suspended sediment concentration. This was then converted into daily suspended sediment output using the measured total daily discharge. The effect of precipitation on the sediment output data was minimized by using an antecedent precipitation index (API), which consists of the precipitation of the current day added by the precipitation of the previous 14 days, where the influence of the previous days decays exponentially with time. The daily total suspended sediment output was divided by the API, to obtain a measure for sediment output independent of precipitation. This sediment output then serves as a measure for the connectivity within the catchment. The connectivity of the four catchments throughout the years will be compared to each other and we hypothesise that the two catchments dominated by forests and pastures will change only slightly throughout the year, whereas we expect to see large differences in connectivity in the two agricultural catchments. The agricultural catchments are likely to display a highly varying connectivity throughout the seasons due to changes in vegetation cover of the fields throughout the year, whereas daily variations will likely be small due to a slowly changing connectivity.

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

    PubMed Central

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

    2015-01-01

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

  4. Wisconsin timber industry: An assessment of timber product output and use, 1992. Forest Service resource bulletin

    SciTech Connect

    Hackett, R.L.; Whipple, J.W.

    1995-09-15

    In this bulletin we discuss recent Wisconsin forest industry trends and report results of a detailed study of forest industry, industrial roundwood production, and associated primary mill wood and bark residue in Wisconsin in 1992. Such detailed information is necessary for intelligent planning and decisionmaking in wood procurement, forest resource management, and forest industry development. Likewise, researchers need current forest industry and industrial roundwood information for planning projects. The last published report from a detailed study of all industrial roundwood output in Wisconsin was in 1990. Most comparisons in this report are with the 1990 study results.

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

    ERIC Educational Resources Information Center

    Long, Patricia N.; Amey, Marilyn J.

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

  6. Combined Assessment of High-Sensitivity Troponin T and Noninvasive Coronary Plaque Composition for the Prediction of Cardiac Outcomes.

    PubMed

    Gitsioudis, Gitsios; Schüssler, Alena; Nagy, Eszter; Maurovich-Horvat, Pál; Buss, Sebastian J; Voss, Andreas; Hosch, Waldemar; Hofmann, Nina; Kauczor, Hans-Ulrich; Giannitsis, Evangelos; Katus, Hugo A; Korosoglou, Grigorios

    2015-07-01

    Purpose To determine the risk-stratification ability of plaque volume and composition assessment with cardiac computed tomographic (CT) angiography and high-sensitivity troponin T (hsTnT) in patients at intermediate risk for coronary artery disease (CAD). Materials and Methods The study complied with the Declaration of Helsinki and was approved by the local ethics committee. All patients gave written informed consent. Five hundred twenty-one consecutive patients (mean age ± standard deviation, 62 years ± 10; 256 men and 265 women) were included in this prospective, observational, longitudinal, single-center study. Quantitative cardiac CT angiography analysis was performed in all patients (for 7690 coronary segments), whereas biomarkers (hsTnT and high-sensitivity C-reactive protein) were available in 408 patients (78%). To evaluate the incremental value of cardiac CT angiography and hsTnT for the prediction of cardiovascular events, multivariate Cox regression and integrated discrimination improvement analysis were applied. Results In 521 patients, 13 hard cardiac events occurred during a mean follow-up period of 2.3 years ± 1.1 (median, 2.4 years; range, 0.5-4.5 years), while 23 patients underwent late coronary revascularization. The Duke clinical score was 51% ± 30, indicating intermediate risk. The presence of no plaques or purely calcified versus noncalcified plaques, plaque volume according to tertiles, and increased hsTnT (?14 pg/mL) was independently associated with hard cardiac events (hazard ratio [HR] = 26.08, 95% confidence interval [CI]: 2.78, 244.99; HR = 12.14, 95% CI: 1.87, 78.74; and HR = 10.31, 95% CI: 2.72, 39.0, respectively; P < .01 for all). Patients with increased hsTnT and plaque burden (n = 53) showed the highest incidence for hard cardiac events (annual rate, 12.7%), followed by those with either increased hsTnT or plaque burden (n = 145; annual rate = 0.44%, P < .03), while those with lower hsTnT and plaque burden exhibited excellent outcomes and no hard event during the follow-up duration (n = 210; annual rate = 0%, P < .001). Conclusion Use of hsTnT as a marker of myocardial microinjury and cardiac CT angiography as a marker of the total atherosclerotic burden improves the prediction of cardiac outcome in patients with presumably stable CAD and may aid in personalized risk stratification in patients at intermediate risk. (©) RSNA, 2015 Online supplemental material is available for this article. PMID:25734549

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

    SciTech Connect

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

    2012-12-01

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

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

    PubMed

    Velarde, Antonio; Dalmau, Antoni

    2012-11-01

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

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

    PubMed Central

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

    2012-01-01

    A new index to assess left ventricular (LV) function in patients implanted with continuous flow left-ventricular assist devices (LVADs) is proposed. Derived from the pump flow signal, this index is defined as the coefficient (k) of the semilogarithmic relationship between “pseudo-ejection” fraction (pEF) and the volume discharged by the pump in diastole, (V d). pEF is defined as the ratio of the “pseudo-stroke volume” (pSV) to V d. The pseudo-stroke volume is the difference between V d and the volume discharged by the pump in systole (V s), both obtained by integrating pump flow with respect to time in a cardiac cycle. k was compared in-vivo with others two indices: the LV pressure-based index, MTP, and the pump flow-based index, IQ. MTP is the slope of the linear regression between the “triple-product” and end-diastolic pressure, EDP. The triple-product, TP = LV SP.dP=dtmax.HR, is the product of LV systolic pressure, maximum time-derivative of LV pressure, and heart rate. IQ is the slope of the linear regression between maximum time-derivative of pump flow, dQ/dtmax, and pump flow peak-to-peak amplitude variation, QP2P. To test the response of k to contractile state changes, contractility was altered through pharmacological interventions. The absolute value of k decreased from 1.354±0.25 (baseline) to 0.685±0.21 after esmolol infusion. The proposed index is sensitive to changes in inotropic state, and has the potential to be used clinically to assess contractile function of patients implanted with VAD. PMID:22254290

  10. Progression of diffuse myocardial fibrosis assessed by cardiac magnetic resonance T? mapping.

    PubMed

    Yi, Colin J; Yang, Eunice; Lai, Shenghan; Gai, Neville; Liu, Chia; Liu, Songtao; Zimmerman, Stefan L; Lima, João A C; Bluemke, David A

    2014-10-01

    To evaluate long-term changes in diffuse myocardial fibrosis using cardiac magnetic resonance (CMR) with late gadolinium enhancement (LGE) and T1 mapping. Patients with chronic stable cardiomyopathy and stable clinical status (n = 52) underwent repeat CMR at a 6 month or greater follow up interval and had LGE and left ventricular (LV) T1 mapping CMR. Diffuse myocardial fibrosis (excluding areas of focal myocardial scar) was assessed by post gadolinium myocardial T1 times. Mean baseline age of 52 patients (66 % male) was 35 ± 19 years with a mean interval between CMR examinations of 2.0 ± 0.8 years. CMR parameters, including LV mass and ejection fraction, showed no change at follow-up CMR (p > 0.05). LVT1 times (excluding focal scar) decreased over the study interval (from 468 ± 106 to 434 ± 82 ms, p = 0.049). 38 Patients had no visual LGE-, while 14 were LGE+. For LGE- patients, greater change in LV mass and end systolic volume index were associated with change in T1 time (? = -2.03 ms/g/m(2), p = 0.035 and ? = 2.1 ms/mL/m(2), p = 0.029, respectively). For LGE+ patients, scar size was stable between CMR1 and CMR2 (10.7 ± 13.8 and 11.5 ± 13.9 g, respectively, p = 0.32). These results suggest that diffuse myocardial fibrosis, as assessed by T1 mapping, progresses over time in patients with chronic stable cardiomyopathy. PMID:24903343

  11. Assessment of Eclipse electron Monte Carlo output prediction for various topologies.

    PubMed

    Lawrence, Shane L; Van Lieshout, Natascha H M; Charland, Paule M

    2015-01-01

    Monte Carlo simulation is deemed to be the leading algorithm for accurate dose calculation with electron beams. Patient anatomy (contours and tissue densities) as well as irradiation geometry is accounted for. The accuracy of the Monitor Unit (MU) determination is one essential aspect of a treatment planning system. Patient-specific quality assurance of a Monte Carlo plan usually involves verification of the MUs with an independent simpler calculation approach, in which flat geometry is to be assumed. The magnitude of the discrepancies between flat and varied surfaces for a few scenarios has been investigated in this study. The ability to predict MUs for various surface topologies by the commercial electron Monte Carlo implementation from Varian Eclipse system (Eclipse eMC) has been evaluated and compared to the Generalized Gaussian Pencil Beam (GGPB) algorithm. Ten phantoms with different topologies were constructed of water-equivalent material. Measurements with a parallel plate ionization chamber were performed using these phantoms to gauge their relative impact on outputs for 6, 9, 12, 16, and 20MeV electron beams from a Varian TrueBeam with cone sizes ranging from 6 × 6 cm2 to 25 × 25 cm2. The corresponding Monte Carlo simulations of the measured geometries were carried out using the CT scans of these phantoms. The results indicated that the Eclipse eMC algorithm can predict these output changes within 3% for most scenarios. However, at the lowest energy, the discrepancy was the greatest, up to 6%. In comparison, the Eclipse GGPB algorithm had much worse agreement, with discrepancies up to 17% at the lowest energies. PMID:26103474

  12. Relative indicators and relational charts for comparative assessment of publication output and citation impact

    Microsoft Academic Search

    A. Schubert; T. Braun

    1986-01-01

    Cross-field comparison ofscientometric indicators\\u000a1 is severely hindered by the differences in publication and citation habits of science fields. However, relating publication and citation indicators to proper field-specific reference standards,relative indicators can be built, which may prove rather useful in the comparative assessment of scientists, groups, institutions or countries. The use ofrelational charts in displaying the indicators broadens the scope

  13. Cardiac T2* MRI assessment in patients with thalassaemia major and its effect on the preference of chelation therapy.

    PubMed

    Akcay, Arzu; Salcioglu, Zafer; Oztarhan, Kazim; Tugcu, Deniz; Aydogan, Gonul; Ayaz, Nuray Aktay; Bornaun, Helen; Sen, Hulya Sayilan; Akici, Ferhan; Akdana, Burhan

    2014-06-01

    The aim of the study is to assess the relationship between T2* magnetic resonance imaging (MRI) values and age, serum ferritin level, left ventricular ejection fraction (LVEF), splenectomy status, and to identify appropriate modifications to chelation therapy based on T2* MRI results of children with thalassaemia major. Sixty-four patients with thalassaemia major (37 girls/27 boys) older than 8 years of age were enrolled in the study. Based on the first T2* MRI, the patients' myocardial iron depositions were classified into three groups: T2* MRI <10 ms (high risk group), T2* MRI 10-20 ms (medium-risk group) and T2* MRI >20 ms (low-risk group). There was no significant relationship between T2* MRI value and ages, serum ferritin levels and splenectomy status of thalassaemia major patients. The mean LVEFs were 60, 75, and 72.5 % in the high-, medium-, and low-risk groups, respectively (P = 0.006). The mean cardiac iron concentrations calculated from the T2* MRI values were 4.96 ± 1.93, 1.65 ± 0.37, and 0.81 ± 0.27 mg/g in the high-, medium-, and low-risk groups, respectively. Chelation therapies were re-designed in 24 (37.5 %) patients according to cardiac risk as assessed by cardiac T2* MRI. In conclusion, until recently, T2* MRI has been employed to demonstrate cardiac siderosis without a direct relationship with the markers used in follow-up of patients with thalassaemia. However, modifications of chelation therapies could reliably be planned according to severity of iron load displayed by T2* MRI. PMID:24719246

  14. Cardiac Output Responses During Exercise in Volume-Expanded Heart Transplant Recipients 1 1 This work was supported by National Institutes of Health Clinical Research Center Grant RR00082 and Dr. Braith was supported by a NIH National Research Service Award (HL08777), Bethesda, Maryland

    Microsoft Academic Search

    Randy W Braith; Mary B Plunkett; Roger M Mills

    1998-01-01

    The mechanisms responsible for immediate adjustments in cardiac output at onset of exercise, in the absence of neural drive, are not well defined in heart transplant (HT) recipients. Seven male HT recipients (mean ± SD 57 ± 6 years) and 7 age-matched sedentary normal control subjects (mean age 57 ± 5 years) performed constant load cycle exercise at 40% of

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

    PubMed Central

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

    2014-01-01

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

  16. Cardiac Rehabilitation

    MedlinePLUS

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

  17. Development and first assessment of a questionnaire for health care utilization and costs for cardiac patients

    PubMed Central

    Schweikert, Bernd; Hahmann, Harry; Leidl, Reiner

    2008-01-01

    Background The valid and reliable measurement of health service utilization, productivity losses and consequently total disease-related costs is a prerequisite for health services research and for health economic analysis. Although administrative data sources are usually considered to be the most accurate, their use is limited as some components of utilization are not systematically captured and, especially in decentralized health care systems, no single source exists for comprehensive utilization and cost data. The aim of this study was to develop and test a questionnaire for the measurement of disease-related costs for patients after an acute cardiac event (ACE). Methods To design the questionnaire, the literature was searched for contributions to the assessment of utilization of health care resources by patient-administered questionnaires. Based on these findings, we developed a retrospective questionnaire appropriate for the measurement of disease-related costs over a period of 3 months in ACE patients. Items were generated by reviewing existing guidelines and by interviewing medical specialists and patients. In this study, the questionnaire was tested on 106 patients, aging 35–65 who were admitted for rehabilitation after ACE. It was compared with prospectively measured data; selected items were compared with administrative data from sickness funds. Results The questionnaire was accepted well (response rate = 88%), and respondents completed the questionnaire in an average time of 27 minutes. Concordance between retrospective and prospective data showed an intraclass correlation (ICC) ranging between 0.57 (cost of medical intake) and 0.9 (hospital days) with the other main items (physician visits, days off work, medication) clustering around 0.7. Comparison between self-reported and administrative data for days off work and hospitalized days were possible for n = 48. Respective ICCs ranged between 0.92 and 0.94, although differences in mean levels were observed. Conclusion The questionnaire was accepted favorably and correlated well with alternative measurement approaches. This first assessment showed promising characteristics of this questionnaire in different aspects of validity for patients with ACE. However, additional research and more extensive tests in other patient groups would be worthwhile. PMID:18803845

  18. Non-invasive assessment of cardiac function and pulmonary vascular resistance in an canine model of acute thromboembolic pulmonary hypertension using 4D flow cardiovascular magnetic resonance

    PubMed Central

    2014-01-01

    Background The purpose of this study was to quantify right (RV) and left (LV) ventricular function, pulmonary artery flow (QP), tricuspid valve regurgitation velocity (TRV), and aorta flow (QS) from a single 4D flow cardiovascular magnetic resonance (CMR) (time-resolved three-directionally motion encoded CMR) sequence in a canine model of acute thromboembolic pulmonary hypertension (PH). Methods Acute PH was induced in six female beagles by microbead injection into the right atrium. Pulmonary arterial (PAP) and pulmonary capillary wedge (PCWP) pressures and cardiac output (CO) were measured by right heart catheterization (RHC) at baseline and following induction of acute PH. Pulmonary vascular resistance (PVRRHC) was calculated from RHC values of PAP, PCWP and CO (PVRRHC?=?(PAP-PCWP)/CO). Cardiac magnetic resonance (CMR) was performed on a 3 T scanner at baseline and following induction of acute PH. RV and LV end-diastolic (EDV) and end-systolic (ESV) volumes were determined from both CINE balanced steady-state free precession (bSSFP) and 4D flow CMR magnitude images. QP, TRV, and QS were determined from manually placed cutplanes in the 4D flow CMR flow-sensitive images in the main (MPA), right (RPA), and left (LPA) pulmonary arteries, the tricuspid valve (TRV), and aorta respectively. MPA, RPA, and LPA flow was also measured using two-dimensional flow-sensitive (2D flow) CMR. Results Biases between 4D flow CMR and bSSFP were 0.8 mL and 1.6 mL for RV EDV and RV ESV, respectively, and 0.8 mL and 4 mL for LV EDV and LV ESV, respectively. Flow in the MPA, RPA, and LPA did not change after induction of acute PAH (p?=?0.42-0.81). MPA, RPA, and LPA flow determined with 4D flow CMR was significantly lower than with 2D flow (p?cardiac function and cardiopulmonary hemodynamic parameters important in the assessment of PH. PMID:24625242

  19. Effect of right ventricular pacing on cardiac apex rotation assessed by a gyroscopic sensor.

    PubMed

    Marcelli, Emanuela; Cercenelli, Laura; Parlapiano, Mario; Fumero, Roberto; Bagnoli, Paola; Costantino, Maria Laura; Plicchi, Gianni

    2007-01-01

    To quantify cardiac apex rotation (CAR), the authors recently proposed the use of a Coriolis force sensor (gyroscope) as an alternative to other complex techniques. The aim of this study was to evaluate the effects of right ventricular (RV) pacing on CAR. A sheep heart was initially paced from the right atrium to induce a normal activation sequence at a fixed heart rate (AAI mode) and then an atrioventricular pacing was performed (DOO mode, AV delay = 60 ms). A small gyroscope was epicardially glued on the cardiac apex to measure the angular velocity (Ang V). From AAI to DOO pacing mode, an increase (+9.2%, p < 0.05) of the maximum systolic twisting velocity (Ang VMAX) and a marked decrease (-19.9%, p < 0.05) of the maximum diastolic untwisting velocity (Ang VMIN) resulted. RV pacing had negligible effects (-3.1%, p = 0.09) on the maximum angle of CAR, obtained by integrating Ang V. The hemodynamic parameters of systolic (LVdP/dtMAX) and diastolic (LVdP/dtMIN) cardiac function showed slight variations (-3.8%, p < 0.05 and +3.9%, p < 0.05, respectively). Results suggest that cardiac dyssynchrony induced by RV pacing can alter the normal physiological ventricular twist patterns, particularly affecting diastolic untwisting velocity. PMID:17515719

  20. A look into Lee's score: peri-operative cardiovascular risk assessment in non-cardiac surgeries—usefulness of revised cardiac risk index

    PubMed Central

    Rao, Jayakeerthi Y.; Yeriswamy, M.C.; Santhosh, M.J.; Shetty, Gurappa G.; Varghese, Kiron; Patil, Chandrakant B.; Iyengar, Shamanna S.

    2012-01-01

    Objective The revised cardiac risk index (RCRI/Lee's score) was designed for peri-operative risk assessment before elective major non-cardiac surgeries. Through this article, we report the usefulness of RCRI in our daily practice, while evaluating patients undergoing surgeries of varying risk. Methods Only referred patients, aged ? 40 years, were included. Risk stratification was done using RCRI scoring system. Patients were categorised into 4 classes depending on 0, 1, 2, and ?3 risk predictors (risk predictors were high-risk surgery, history of ischaemic heart disease (IHD), diabetes on insulin, history of stroke (cerebrovascular accident [CVA]), history of congestive heart failure (CHF) and serum creatinine of >2 mg%). Electrocardiograms (ECG) were done in all patients, while troponin I in intermediate and high-risk patients, and in others if symptomatic. Perioperative cardiovascular events were managed appropriately. Results Of the 920 patients included, only 853 patients were analysed as 67 patients were not operated upon. The mean age was 59 ± 11years and 46% of the patients were women. Two hundred and ninety-two underwent high-risk surgeries, 97 patients had history of IHD, 89 had history of CHF, 36 gave history of CVA, 269 patients were diabetics on insulin and 68 had serum creatinine >2 mg%. Number of patients in Lee's classes I, II, III, and IV were 311, 347, 150, and 52, respectively. 26 out of 853 patients had peri-operative events. Of the six variables in RCRI, only history of IHD was an independent predictor of events. Event rates increased as the RCRI class increased, i.e. 1.7%, 2.0%, 6.7%, and 7.7% for classes I–IV, respectively. Age >70 years, poor general medical condition, emergency surgery and left bundle branch block (LBBB) on ECG, were significantly associated with peri-operative events. Conclusion The RCRI is a useful tool in pre-operative risk stratification. It should perhaps be further updated to improve its predictive accuracy. PMID:22572486

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed

    Mhajna, Muhammad; Abboud, Shimon

    2013-05-01

    The present theoretical study examines the ability to estimate cardiac stroke volume (CSV) in patients with implanted cardiac pacemaker using parametric electrical impedance tomography (pEIT) in a 2D computerized model of the thorax. CSV is a direct indicator of the cardiac pumping efficiency. The commonly used methods for measuring CSV require the invasive procedure of right heart catheterization or use expensive imaging techniques (i.e., MRI). Hence, experience with these techniques for diagnosis and monitoring has been limited to hospitalized patients. In the present study, pEIT scheme was applied in a computerized 2D model of the human thorax with implanted cardiac device to determine the left ventricular (LV) volume at different cardiac cycle phases. The LV was simulated as a prolate ellipse with its axes' lengths as the reconstruction parameters while all other geometries and conductivity values remained constant. An optimization was carried out in order to ensure that the ellipse is the appropriate model for the LV at each cardiac cycle phase. LV volumes calculated by both the pEIT algorithm and the ellipsoid model are consistent. A high correlation (??=?0.99) between the true and reconstructed volumes was found. The SV calculation error was ?1%. The results suggest that the LV volume can be estimated using the pEIT method in a 2D computerized model, and that the method has the potential to be used for monitoring patients with implanted cardiac pacemaker. PMID:23606371

  3. Multicentre evaluation of the diagnostic value of cardiac troponin T, CK-MB mass, and myoglobin for assessing patients with suspected acute coronary syndromes in routine clinical practice

    PubMed Central

    Collinson, P O; Stubbs, P J; Kessler, A-C

    2003-01-01

    Objective: To assess the diagnostic efficiency of the third generation cardiac troponin T assay in routine clinical practice. Design: Prospective observational study of unselected consecutive admissions. Setting: Multicentre study in 43 teaching and non-teaching hospitals in 13 countries. Subjects: 1105 hospital admissions, median age 67 years (range 15–96 years, 63.7% male) with suspected acute coronary syndromes (72.3% of cases) or other non-specific symptoms where cardiac disease required exclusion (27.7%). Interventions: Over the study period, myoglobin, creatine kinase MB isoenzyme (CK-MB), and cardiac troponin T where measured in parallel with conventional diagnostic tests. Final diagnostic classification involved standard ECG changes and CK-MB mass exceeding 5.0 ?g/l. Main outcome measures: Diagnostic efficiency was assessed by receiver operator characteristic curve analysis including and excluding patients with unstable angina. Results: Measurement of cardiac troponin T was diagnostically equivalent to CK-MB and both were better than myoglobin, with areas under the curve at 12 hours of 0.94, 0.99, and 0.80, respectively. Diagnostic criteria using CK-MB were inadequate and showed bias when patients with unstable angina were included. Elevations of cardiac troponin T did not occur when cardiac disease could be categorically excluded but were found in clinical conditions other than suspected acute coronary syndromes. Conclusions: CK-MB is unsuitable as a diagnostic gold standard even at the proposed lower threshold. A lower cut off for cardiac troponin T of 0.05 ?g/l should be used for diagnosis of acute myocardial infarction. Diagnosis of acute myocardial infarction cannot be made solely on the basis of a cardiac troponin T result. PMID:12591831

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

    NASA Astrophysics Data System (ADS)

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

    2013-11-01

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

  5. Relationship between peak cardiac pumping capability and indices of cardio-respiratory fitness in healthy individuals.

    PubMed

    Jakovljevic, Djordje G; Popadic-Gacesa, Jelena Z; Barak, Otto F; Nunan, David; Donovan, Gay; Trenell, Michael I; Grujic, Nikola G; Brodie, David A

    2012-09-01

    Cardiac power output (CPO) is a unique and direct measure of overall cardiac function (i.e. cardiac pumping capability) that integrates both flow- and pressure-generating capacities of the heart. The present study assessed the relationship between peak exercise CPO and selected indices of cardio-respiratory fitness. Thirty-seven healthy adults (23 men and 14 women) performed an incremental exercise test to volitional fatigue using the Bruce protocol with gas exchange and ventilatory measurements. Following a 40-min recovery, the subjects performed a constant maximum workload exercise test at or above 95% of maximal oxygen consumption. Cardiac output was measured using the exponential CO(2) rebreathing method. The CPO, expressed in W, was calculated as the product of the mean arterial blood pressure and cardiac output. At peak exercise, CPO was well correlated with cardiac output (r = 0·92, P<0·01), stroke volume (r = 0·90, P<0·01) and peak oxygen consumption (r = 0·77, P<0·01). The coefficient of correlation was moderate between CPO and anaerobic threshold (r = 0·47, P<0·01), oxygen pulse (r = 0·57, P<0·01), minute ventilation (r = 0·53, P<0·01) and carbon dioxide production (r = 0·56, P<0·01). Small but significant relationship was found between peak CPO and peak heart rate (r = 0·23, P<0·05). These findings suggest that only peak cardiac output and stroke volume truly reflect CPO. Other indices of cardio-respiratory fitness such as oxygen consumption, anaerobic threshold, oxygen pulse, minute ventilation, carbon dioxide production and heart rate should not be used as surrogates for overall cardiac function and pumping capability of the heart. PMID:22856346

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

    NASA Astrophysics Data System (ADS)

    Takahashi, Hiroki; Hasegawa, Hideyuki; Kanai, Hiroshi

    2015-07-01

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

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

    PubMed Central

    Kreuzer, Peter M.; Landgrebe, Michael; Husser, Oliver; Resch, Markus; Schecklmann, Martin; Geisreiter, Florian; Poeppl, Timm B.; Prasser, Sarah Julia; Hajak, Goeran; Langguth, Berthold

    2012-01-01

    Background: Vagus nerve stimulation has been successfully used as a treatment strategy for epilepsy and affective disorders for years. Transcutaneous vagus nerve stimulation (tVNS) is a new non-invasive method to stimulate the vagus nerve, which has been shown to modulate neuronal activity in distinct brain areas. Objectives: Here we report effects of tVNS on cardiac function from a pilot study, which was conducted to evaluate the feasibility and safety of tVNS for the treatment of chronic tinnitus. Methods: Twenty-four patients with chronic tinnitus underwent treatment with tVNS over 3–10?weeks in an open single-armed pilot study. Safety criteria and practical usability of the neurostimulating device were to investigate by clinical examination and electrocardiography at baseline and at several visits during and after tVNS treatment (week 2, 4, 8, 16, and 24). Results: Two adverse cardiac events (one classified as a severe adverse event) were registered but considered very unlikely to have been caused by the tVNS device. Retrospective analyses of electrocardiographic parameters revealed a trend toward shortening of the QRS complex after tVNS. Conclusion: To our knowledge this is one of the first studies investigating feasibility and safety of tVNS in a clinical sample. In those subjects with no known pre-existing cardiac pathology, preliminary data do not indicate arrhythmic effects of tVNS. PMID:22891061

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

    PubMed Central

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

    2013-01-01

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

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

    PubMed Central

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

    2008-01-01

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

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

    SciTech Connect

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

    1989-06-01

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

  11. Cardiac assessment of veteran endurance athletes: a 12 year follow up study

    PubMed Central

    Hood, S.; Northcote, R. J.

    1999-01-01

    OBJECTIVES: Sustained aerobic dynamic exercise is beneficial in preventing cardiovascular disease. The effect of lifelong endurance exercise on cardiac structure and function is less well documented, however. A 12 year follow up of 20 veteran athletes was performed, as longitudinal studies in such cohorts are rare. METHODS: Routine echocardiography was repeated as was resting, exercise, and 24 hour electrocardiography. RESULTS: Nineteen returned for screening. Mean (SD) age was 67 (6.2) years (range 56-83). Two individuals had had permanent pacemakers implanted (one for symptomatic atrial fibrillation with complete heart block, the other for asystole lasting up to 15 seconds). Only two athletes had asystolic pauses in excess of two seconds compared with seven athletes in 1985. Of these seven, five had no asystole on follow up. Two of these five had reduced their average running distance by about 15-20 miles a week. One athlete sustained an acute myocardial infarction during a competitive race in 1988. Three athletes had undergone coronary arteriography during the 12 years of follow up but none had obstructive coronary artery disease. Ten of 19 (53%) had echo evidence of left ventricular hypertrophy in 1997 but only two (11%) had left ventricular dilatation. Ten athletes had ventricular couplets on follow up compared with only two in 1985. CONCLUSIONS: Although the benefits of moderate regular exercise are undisputed, high intensity lifelong endurance exercise may be associated with altered cardiac structure and function. These adaptations to more extreme forms of exercise merit caution in the interpretation of standard cardiac investigations in the older athletic population. On rare occasions, these changes may be deleterious. ??? PMID:10450477

  12. Central venous pressure, pulmonary capillary wedge pressure and intrathoracic blood volumes as preload indicators in cardiac surgery patients 1 Presented at the 11th Annual Meeting of The European Association for Cardiothoracic Surgery, Copenhagen, Denmark, September 28 – October 1, 1997. Winner of the Young Investigator's Award. 1

    Microsoft Academic Search

    O Gödje; M Peyerl; T Seebauer; P Lamm; H Mair; B Reichart

    1998-01-01

    Objective: Monitoring of cardiac preload is mainly performed by measurement of central venous and pulmonary capillary wedge pressure in combination with assessment of cardiac output, applying the pulmonary arterial thermal dilution technique. However, the filling pressures are negatively influenced by mechanical ventilation and the pulmonary artery catheter is criticized because of its inherent risks. Measurement of right atria, right ventricular,

  13. Smooth, cardiac and skeletal muscle myosin force and motion generation assessed by cross-bridge mechanical interactions in vitro

    Microsoft Academic Search

    D. E. Harris; S. S. Work; R. K. Wright; N. R. Alpert; D. M. Warshaw

    1994-01-01

    Differences in the mechanical properties of mammalian smooth, skeletal, and cardiac muscle have led to the proposal that the myosin isozymes expressed by these tissues may differ in their molecular mechanics. To test this hypothesis, mixtures of fast skeletal, V1 cardiac, V3 cardiac and smooth muscle (phosphorylated and unphosphorylated) myosin were studied in an in vitro motility assay in which

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

    PubMed Central

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

    2015-01-01

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

  15. Non-invasive cardiac output monitoring

    Microsoft Academic Search

    D. A. Hett; M. M. Jonas

    2003-01-01

    Outcomes in the management of critically ill patients may be improved using goal directed peri-operative haemodynamic monitoring. A conservative approach may no longer be acceptable but in view of the significant morbidity associated with balloon tipped flow directed pulmonary artery catheters a non-invasive approach would be preferable. In this review we consider the different non-invasive techniques available and discuss the

  16. Non-invasive cardiac output monitoring

    Microsoft Academic Search

    D. A. Hett; M. M. Jonas

    2004-01-01

    Outcomes in the management of critically ill patients may be improved using goal-directed peri-operative haemodynamic monitoring. A conservative approach may no longer be acceptable but in view of the significant morbidity associated with balloon tipped flow directed pulmonary artery catheters a non-invasive approach would be preferable. In this review we consider the different non-invasive techniques available and discuss the advantages

  17. Cardiac fiber unfolding by semidefinite programming.

    PubMed

    Li, Hongying; Robini, Marc C; Yang, Feng; Magnin, Isabelle; Zhu, Yuemin

    2015-02-01

    Diffusion-tensor imaging allows noninvasive assessment of the myocardial fiber architecture, which is fundamental in understanding the mechanics of the heart. In this context, tractography techniques are often used for representing and visualizing cardiac fibers, but their output is only qualitative. We introduce here a new framework toward a more quantitative description of the cardiac fiber architecture from tractography results. The proposed approach consists in taking three-dimensional (3-D) fiber tracts as inputs, and then unfolding these fibers in the Euclidean plane under local isometry constraints using semidefinite programming. The solution of the unfolding problem takes the form of a Gram matrix which defines the two-dimensional (2-D) embedding of the fibers and whose spectrum provides quantitative information on their organization. Experiments on synthetic and real data show that unfolding makes it easier to observe and to study the cardiac fiber architecture. Our conclusion is that 2-D embedding of cardiac fibers is a promising approach to supplement 3-D rendering for understanding the functioning of the heart. PMID:25291787

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

    PubMed Central

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

    2014-01-01

    Objectives Since diastolic abnormalities are typical findings of cardiac amyloidosis (CA), we hypothesized that speckle-tracking-imaging (STI) derived longitudinal early diastolic strain rate (LSRdias) could predict outcome in CA patients with preserved left ventricular ejection fraction (LVEF >50%). Background Diastolic abnormalities including altered early filling are typical findings and are related to outcome in CA patients. Reduced longitudinal systolic strain (LSsys) assessed by STI predicts increased mortality in CA patients. It remains unknown if LSRdias also related to outcome in these patients. Methods Conventional echocardiography and STI were performed in 41 CA patients with preserved LVEF (25 male; mean age 65±9 years). Global and segmental LSsys and LSRdias were obtained in six LV segments from apical 4-chamber views. Results Nineteen (46%) out of 41 CA patients died during a median of 16 months (quartiles 5–35 months) follow-up. Baseline mitral annular plane systolic excursion (MAPSE, 6±2 vs. 8±3 mm), global LSRdias and basal-septal LSRdias were significantly lower in non-survivors than in survivors (all p<0.05). NYHA class, number of non-cardiac organs involved, MAPSE, mid-septal LSsys, global LSRdias, basal-septal LSRdias and E/LSRdias were the univariable predictors of all-cause death. Multivariable analysis showed that number of non-cardiac organs involved (hazard ratio [HR] ?=?1.96, 95% confidence interval [CI] 1.17–3.26, P?=?0.010), global LSRdias (HR?=?7.30, 95% CI 2.08–25.65, P?=?0.002), and E/LSRdias (HR?=?2.98, 95% CI 1.54–5.79, P?=?0.001) remained independently predictive of increased mortality risk. The prognostic performance of global LSRdias was optimal at a cutoff value of 0.85 S?1 (sensitivity 68%, specificity 67%). Global LSRdias <0.85 S?1 predicted a 4-fold increased mortality in CA patients with preserved LVEF. Conclusions STI-derived early diastolic strain rate is a powerful independent predictor of survival in CA patients with preserved LVEF. PMID:25542015

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

    PubMed

    Sugisaki, Norihide; Okada, Junichi; Kanehisa, Hiroaki

    2013-01-01

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

  20. A thorough QT study to assess the effects of tbo-filgrastim on cardiac repolarization in healthy subjects

    PubMed Central

    Adar, Liat; Avisar, Noa; Lammerich, Andreas; Kleiman, Robert B; Spiegelstein, Ofer

    2015-01-01

    Tbo-filgrastim is a recombinant human granulocyte colony-stimulating factor approved by the US Food and Drug Administration to reduce the duration of severe neutropenia in patients with nonmyeloid malignancies receiving myelosuppressive anticancer drugs associated with a clinically significant incidence of febrile neutropenia. We assessed the effect of tbo-filgrastim on cardiac conduction and repolarization in healthy subjects. A three-arm, parallel-group, active- and placebo-controlled, double-blind study randomized healthy adults to a single 5 ?g/kg intravenous tbo-filgrastim infusion, a single intravenous placebo infusion, or a single 400 mg moxifloxacin oral dose. The primary end point was placebo-corrected time-matched change from baseline in QT interval corrected using a QT individual correction (QTcI) method. Secondary end points included heart rate, PR interval, QRS duration, change in electrocardiogram patterns, correlation between QTcI change from baseline (milliseconds) and tbo-filgrastim serum concentrations, and safety variables. A total of 145 subjects were enrolled (50 tbo-filgrastim, 50 placebo, 45 moxifloxacin). Peak placebo-corrected change from baseline for QTcI with tbo-filgrastim was 3.5 milliseconds, with a two-sided 95% upper confidence interval of 7.2 milliseconds, demonstrating no signal for any tbo-filgrastim effect on QTc. Concentration-effect modeling showed no evidence of an effect of tbo-filgrastim on cardiac repolarization. Tbo-filgrastim produced no clinically significant changes in other electrocardiogram parameters. Tbo-filgrastim was well tolerated. PMID:26028962

  1. A thorough QT study to assess the effects of tbo-filgrastim on cardiac repolarization in healthy subjects.

    PubMed

    Adar, Liat; Avisar, Noa; Lammerich, Andreas; Kleiman, Robert B; Spiegelstein, Ofer

    2015-01-01

    Tbo-filgrastim is a recombinant human granulocyte colony-stimulating factor approved by the US Food and Drug Administration to reduce the duration of severe neutropenia in patients with nonmyeloid malignancies receiving myelosuppressive anticancer drugs associated with a clinically significant incidence of febrile neutropenia. We assessed the effect of tbo-filgrastim on cardiac conduction and repolarization in healthy subjects. A three-arm, parallel-group, active- and placebo-controlled, double-blind study randomized healthy adults to a single 5 ?g/kg intravenous tbo-filgrastim infusion, a single intravenous placebo infusion, or a single 400 mg moxifloxacin oral dose. The primary end point was placebo-corrected time-matched change from baseline in QT interval corrected using a QT individual correction (QTcI) method. Secondary end points included heart rate, PR interval, QRS duration, change in electrocardiogram patterns, correlation between QTcI change from baseline (milliseconds) and tbo-filgrastim serum concentrations, and safety variables. A total of 145 subjects were enrolled (50 tbo-filgrastim, 50 placebo, 45 moxifloxacin). Peak placebo-corrected change from baseline for QTcI with tbo-filgrastim was 3.5 milliseconds, with a two-sided 95% upper confidence interval of 7.2 milliseconds, demonstrating no signal for any tbo-filgrastim effect on QTc. Concentration-effect modeling showed no evidence of an effect of tbo-filgrastim on cardiac repolarization. Tbo-filgrastim produced no clinically significant changes in other electrocardiogram parameters. Tbo-filgrastim was well tolerated. PMID:26028962

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

    PubMed Central

    Kensah, George; Viering, Jörg; Schumann, Henning; Dahlmann, Julia; Meyer, Heiko; Skvorc, David; Bär, Antonia; Akhyari, Payam; Heisterkamp, Alexander; Haverich, Axel; Martin, Ulrich

    2011-01-01

    Stem cell-based cardiac tissue engineering is a promising approach for regenerative therapy of the injured heart. At present, the small number of stem cell-derived cardiomyocytes that can be obtained using current culture and enrichment techniques represents one of the key limitations for the development of functional bioartificial cardiac tissue (BCT). We have addressed this problem by construction of a novel bioreactor with functional features of larger systems that enables the generation and in situ monitoring of miniaturized BCTs. BCTs were generated from rat cardiomyocytes to demonstrate advantages and usefulness of the bioreactor. Tissues showed spontaneous, synchronized contractions with cell orientation along the axis of strain. Cyclic stretch induced cardiomyocyte hypertrophy, demonstrated by a shift of myosin heavy chain expression from the alpha to beta isoform, together with elevated levels of atrial natriuretic factor. Stretch led to a moderate increase in systolic force (1.42?±?0.09?mN vs. 0.96?±?0.09?mN in controls), with significantly higher forces observed after ?-adrenergic stimulation with noradrenalin (2.54?±?0.11?mN). Combined mechanical and ?-adrenergic stimulation had no synergistic effect. This study demonstrates for the first time that mechanical stimulation and direct real-time contraction force measurement can be combined into a single multimodal bioreactor system, including electrical stimulation of excitable tissue, perfusion of the culture chamber, and the possibility of (fluorescence) microscopic assessment during continuous cultivation. Thus, this bioreactor represents a valuable tool for monitoring tissue development and, ultimately, the optimization of stem cell-based tissue replacement strategies in regenerative medicine. PMID:21142417

  3. The course of depression 10-weeks post-acute coronary syndrome: assessment using the cardiac depression visual analogue scale.

    PubMed

    Di Benedetto, Mirella; Kent, Stephen; Lindner, Helen

    2008-08-01

    This study investigated depressed mood post-acute coronary syndrome in an Australian sample using the Cardiac Depression Visual Analogue Scale (CD-VAS), which was developed to assess the depression-related symptoms of reduced pleasure, memory, activity, future pessimism, increased irritation and sleep problems. The Beck Depression Inventory-II, the Cardiac Depression Scale (CDS) and a demographic medical questionnaire were administered at 2 weeks post-ACS to an initial sample of 13 female and 45 male participants whose mean age was 59.16 (SD=11.13) years (range 38-79). Depressed and non-depressed participants, determined by the CDS, then kept a CD-VAS diary between 2 and 12 weeks. 32 participants kept the diary for the entire 10 weeks. Total CD-VAS scores remained elevated in the depressed group for the entire period. The groups differed on the Pleasure, Memory and Future items for a total of 6, 6 and 5 weeks, respectively, and differed on the Activity item only at 1, 3 and 5 weeks. No group differences were seen in the Irritation or Sleep items. Within the depressed group, the only CD-VAS items that differed from each other across time were Irritation and Activity. Further, the Sleep, Irritation and Activity items had a significant time effect. These results indicate that although overall depression, as measured by the CD-VAS, remained elevated in the depressed group, there were key differences in recovery rates of specific depression-related symptoms. These differences could be useful indicators in the treatment of depression post-ACS. PMID:18825586

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

    PubMed Central

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

    2014-01-01

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

  5. Cardiac rehabilitation and cardiovascular disability: role in assessment and improving functional capacity: a position statement from the American Association of Cardiovascular and Pulmonary Rehabilitation.

    PubMed

    Hamm, Larry F; Wenger, Nanette K; Arena, Ross; Forman, Daniel E; Lavie, Carl J; Miller, Todd D; Thomas, Randal J

    2013-01-01

    The Social Security Administration (SSA) oversees the disability determination process and the payment of disability benefits to Americans. According to recent SSA data, approximately 900 000 persons are receiving cardiovascular disability payments and about 145 000 adult claims for cardiovascular disability are processed by the SSA annually. An objective and comprehensive examination of functional capacity is an important part of the disability assessment process. This statement reviews various protocols for disability assessment of aerobic capacity, muscle function, and the physical requirements of job tasks. Cardiac rehabilitation programs are ideal settings for conducting comprehensive disability assessments of functional capacity in persons with cardiovascular disease. In addition, exercise training provided by cardiac rehabilitation programs can increase functional capacity in most patients. PMID:23254246

  6. Maternal hyperoxygenation and foetal cardiac MRI in the assessment of the borderline left ventricle.

    PubMed

    Borik, Sharon; Macgowan, Christopher K; Seed, Mike

    2015-08-01

    Using phase-contrast MRI in a foetus with borderline left ventricular hypoplasia at 37 weeks' gestation we showed an increase in pulmonary blood flow during maternal hyperoxygenation. The associated increase in venous return to the left atrium, however, resulted in reversal of the atrial shunt, with no improvement in left ventricular output. The child initially underwent single ventricle palliation with a neonatal hybrid procedure, but following postnatal growth of the left ventricle tolerated conversion to a biventricular circulation at 5 months of age. We conclude that when there is significant restriction of filling or outflow obstruction across the left heart, neither prenatal nor postnatal acute pulmonary vasodilation can augment left ventricular output enough to support a biventricular circulation. Chronic pulmonary vasodilation may stimulate the growth of the left-sided structures allowing biventricular repair, raising the intriguing question of whether chronic maternal oxygen therapy might obviate the need for neonatal single ventricle pallation in the setting of borderline left ventricular hypoplasia. PMID:25275342

  7. Assessment of the role of the renin-angiotensin system in cardiac contractility utilizing the renin inhibitor remikiren.

    PubMed Central

    van Kats, J. P.; Sassen, L. M.; Danser, A. H.; Polak, M. P.; Soei, L. K.; Derkx, F. H.; Schalekamp, M. A.; Verdouw, P. D.

    1996-01-01

    1. The role of the renin-angiotensin system in the regulation of myocardial contractility is still debated. In order to investigate whether renin inhibition affects myocardial contractility and whether this action depends on intracardiac rather than circulating angiotensin II, the regional myocardial effects of systemic (i.v.) and intracoronary (i.c.) infusions of the renin inhibitor remikiren, were compared and related to the effects on systemic haemodynamics and circulating angiotensin II in open-chest anaesthetized pigs (25-30 kg). The specificity of the remikiren-induced effects was tested (1) by studying its i.c. effects after administration of the AT1-receptor antagonist L-158,809 and (2) by measuring its effects on contractile force of porcine isolated cardiac trabeculae. 2. Consecutive 10 min i.v. infusions of remikiren were given at 2, 5, 10 and 20 mg min-1. Mean arterial pressure (MAP), cardiac output (CO), heart rate (HR), systemic vascular resistance (SVR), myocardial oxygen consumption (MVO2) and left ventricular (LV) dP/dtmax were not affected by remikiren at 2 and 5 mg min-1, and were lowered at higher doses. At the highest dose, MAP decreased by 48%, CO by 13%, HR by 14%, SVR by 40%, MVO2 by 28% and LV dp/dtmax by 52% (mean values; P < 0.05 for difference from baseline, n = 5). The decrease in MVO2 was accompanied by a decrease in myocardial work (MAP x CO), but the larger decline in work (55% vs. 28%; P < 0.05) implies a reduced myocardial efficiency ((MAP x CO)/MVO2). 3. Consecutive 10 min i.c. infusions of remikiren were given at 0.2, 0.5, 1, 2, 5 and 10 mg min-1. MAP, CO, MVO2 and LV dP/dtmax were not affected by remikiren at 0.2, 0.5 and 1 mg min-1, and were reduced at higher doses. At the highest dose, MAP decreased by 31%, CO by 26%, MVO2 by 46% and LV dP/dtmax by 43% (mean values; P < 0.05 for difference from baseline, n = 6). HR and SVR did not change at any dose. 4. Thirty minutes after a 10 min i.v. infusion of the AT1 receptor antagonist, L-158,809 at 1 mg min-1, consecutive 10 min i.c. infusions (n = 5) of remikiren at 2, 5 and 10 mg min-1 no longer affected CO and MVO2, and decreased LV dP/dtmax by maximally 27% (P < 0.05) and MAP by 14% (P < 0.05), which was less than without AT1-receptor blockade (P < 0.05). HR and SVR remained unaffected. 5. Plasma renin activity and angiotensin I and II were reduced to levels at or below the detection limit at doses of remikiren that were not high enough to affect systemic haemodynamics or regional myocardial function, both after i.v. and i.c. infusion. 6. Remikiren (10(-10) to 10(-4) M) did not affect contractile force of porcine isolated cardiac trabeculae precontracted with noradrenaline. In trabeculae that were not precontracted no decrease in baseline contractility was observed with remikiren in concentrations up to 10(-5) M, whereas at 10(-4) M baseline contractility decreased by 19% (P < 0.05). 7. Results show that with remikiren i.v., at the doses we used, blood pressure was lowered primarily by vasodilation and with remikiren i.c. by cardiac depression. The blood levels of remikiren required for its vasodilator action are lower than the levels affecting cardiac contractile function. A decrease in circulating angiotensin II does not appear to be the sole explanation for these haemodynamic responses. Data support the contention that myocardial contractility is increased by renin-dependent angiotensin II formation in the heart. PMID:8851507

  8. Assessment of arterial stiffness and cardiovascular hemodynamics by oscillometric method in psoriasis patients with normal cardiac functions.

    PubMed

    Sunbul, Murat; Seckin, Dilek; Durmus, Erdal; Ozgen, Zuleyha; Bozbay, Mehmet; Bozbay, Ayfer; Kivrak, Tarik; Oguz, Mustafa; Sari, Ibrahim; Ergun, Tulin; Agirbasli, Mehmet

    2015-05-01

    Arterial stiffness is associated with increased cardiovascular risk. Pulse wave velocity (PWV) and augmentation index (AIx) are non-invasive markers for assessment of arterial stiffness. Increased arterial stiffness is associated with atherosclerosis in patients with psoriasis. Previous studies have shown that high neutrophil-to-lymphocyte ratio (NLR) predicts poor cardiovascular outcome. The aim of this study was to evaluate arterial stiffness and cardiovascular hemodynamics by oscillometric method in psoriasis patients with normal cardiac functions. Fifty consecutive patients with the diagnosis of psoriasis and 50 controls were included in the study. NLR was calculated as the ratio of neutrophil count to lymphocyte count. All patients underwent echocardiographic examination. Measurements of arterial stiffness were carried out using a Mobil-O-Graph arteriograph system. Fifty patients with psoriasis (26 male, mean age 43.3 ± 13.2 years) and 50 controls (33 male, mean age 45.0 ± 6.1 years) were included into the study. The distribution of cardiovascular risk factors was similar between the two groups, and NLR was significantly higher in patients with psoriasis (2.74 ± 1.78 versus 1.82 ± 0.52, p = 0.002). There was a weak correlation between NLR and PASI score without reaching statistical significance (r = 0.300, p = 0.060). While echocardiographic and hemodynamic parameters were comparable between psoriasis and control groups, heart rate was significantly higher in psoriasis group (81.5 ± 15.1 and 75.2 ± 11.8 beats/min, p = 0.021). Psoriasis patients had significantly higher AIx and PWV values as compared to controls (25.8 ± 13.1 versus 17.4 ± 12.3 %, p = 0.001 and 6.78 ± 1.42 versus 6.18 ± 0.80 m/s, p = 0.011, respectively). AI and PWV were significantly associated with psoriasis when adjusted by heart rate (p = 0.005, odds ratio 1.04, 95 % confidence interval 1.01-1.08 and p = 0.035, odds ratio 1.52, 95 % confidence interval 1.02-2.26, respectively). PWV significantly correlated with blood pressure, lipid levels, and several echocardiographic indices. AIx only correlated with left atrial diameter (r = 291, p = 0.040). Linear regression analysis was performed to find predictors of PWV. Central systolic blood pressure, left atrial diameter, and total cholesterol were independent predictors of PWV. PWV and AIx were significantly higher in patients with psoriasis. Assessment of arterial stiffness parameters may be useful for early detection of cardiovascular deterioration in psoriasis patients with normal cardiac functions. Novel inflammatory biomarkers such as NLR may elucidate the mechanism of vascular dysfunction in such patients. PMID:24633494

  9. Assessment of the intrapulmonary ventilation-perfusion distribution after the Fontan procedure for complex cardiac anomalies: Relation to pulmonary hemodynamics

    SciTech Connect

    Matsushita, T.; Matsuda, H.; Ogawa, M.; Ohno, K.; Sano, T.; Nakano, S.; Shimazaki, Y.; Nakahara, K.; Arisawa, J.; Kozuka, T. (Osaka Univ. Medical School (Japan))

    1990-03-15

    In 12 patients who underwent the Fontan procedure for complex cardiac anomalies, lung scanning with xenon-133 was performed to assess the intrapulmonary ventilation-perfusion distribution, and comparison was made with a control group. All data were then analyzed in relation to either pre- or postoperative pulmonary hemodynamic data. In ventilation scans, the intrapulmonary distribution in the right lung was almost normal. In perfusion scans, an abnormal increased upper to lower lobe perfusion ratio greater than the normal value found in the control group was noted in seven patients (58.3%). There was a significant correlation (p less than 0.02) between the upper to lower lobe perfusion ratio and postoperative pulmonary vascular resistance. Furthermore, this perfusion ratio correlated inversely with the preoperative (p less than 0.005) and postoperative (p less than 0.02) right pulmonary artery area index, defined as the ratio of cross-sectional area to the normal value. Of five patients with less than 90% arterial oxygen saturation, four showed an abnormal distribution of pulmonary blood flow greater than the normal perfusion ratio. No patient had evidence of a pulmonary arteriovenous fistula by the echocardiographic contrast study. These results suggest that abnormal distribution of pulmonary blood flow to the upper lung segment may develop in patients after the Fontan procedure, and that insufficient size of the pulmonary artery before operation and the consequent postoperative elevation of pulmonary vascular resistance may be responsible for this perfusion abnormality.

  10. [Multidisciplinary team in cardiac rehabilitation and secondary prevention, from the assessment to the education: an educational project].

    PubMed

    Da Vico, Letizia; Ciompi, Maddalena; Schininà, Francesca; Sogaro, Elena; Mannelli, Weruska; Cortini, Sandro

    2014-03-01

    The authors explain the training project: "Multidisciplinarity in cardiac rehabilitation and secondary prevention: from the evaluation to the therapeutic education", the rationale and purpose of a pathway for patients with ischemic heart disease treated in the acute phase with both medical and surgical means, and then placed in a rehabilitation program. The training project was transformed into a learning event for the Region of Sicily and later for the Region of Tuscany that has adopted it, encouraging the spread over the entire region. It highlights the role of the team, which focuses on the patient, converging on it multidisciplinary expertise whose goal is the reintegration of the subjects in their life-context, with appropriate evaluation, treatment and changes in lifestyle. From the valuations and declining the specific interventions to each job profile according to the principle of synergy obtained by multi-professional integration. All phases of the training project (assessment, intervention, evaluation) are addressed by each of the professionals (nurse, dietitian, physiotherapist, psychologist) that under the responsibility of the cardiologist realize, within the welfare, a concrete process of therapeutic education from which no one can ignore the "vision" of a global care of the patient. PMID:25508791

  11. [Multidisciplinary team in cardiac rehabilitation and secondary prevention, from the assessment to the education: an educational project].

    PubMed

    Da Vico, Letizia; Ciompi, Maddalena; Schininà, Francesca; Sogaro, Elena; Mannelli, Weruska; Cortini, Sandro

    2014-03-01

    The authors explain the training project: "Multidisciplinarity in cardiac rehabilitation and secondary prevention: from the evaluation to the therapeutic education", the rationale and purpose of a pathway for patients with ischemic heart disease treated in the acute phase with both medical and surgical means, and then placed in a rehabilitation program. The training project was transformed into a learning event for the Region of Sicily and later for the Region of Tuscany that has adopted it, encouraging the spread over the entire region. It highlights the role of the team, which focuses on the patient, converging on it multidisciplinary expertise whose goal is the reintegration of the subjects in their life-context, with appropriate evaluation, treatment and changes in lifestyle. From the valuations and declining the specific interventions to each job profile according to the principle of synergy obtained by multi-professional integration. All phases of the training project (assessment, intervention, evaluation) are addressed by each of the professionals (nurse, dietitian, physiotherapist, psychologist) that under the responsibility of the cardiologist realize, within the welfare, a concrete process of therapeutic education from which no one can ignore the "vision" of a global care of the patient. PMID:25481939

  12. Assessment of New Immunosuppressive Drugs in a Rat Cardiac Allograft Heterotopic Model

    Microsoft Academic Search

    B. Walpoth; J. Galdikas; T. Vorburger; H. J. Altermatt; T. Schaffner; U. Althaus; M. Billingham; R. Morris

    1992-01-01

    We assessed FK506 (FK) and rapamycin (RPM) in a heterotopic abdominal rat heart transplant model using a major histocompatibility mismatch (DA to LEW). The end point of our study was histologic grading of rejection (Billingham and working formulation) at 1 week. Two doses of FK (2.0 and 8.0mg\\/kg p.o., q.d.) and RPM (1.5 and 6.0mg\\/kg i.p., q.d.) were compared to

  13. Role of cardiac catheterization and percutaneous coronary intervention in the preoperative assessment and management of patients before orthotopic liver transplantation.

    PubMed

    Maddur, Haripriya; Bourdillon, Patrick D; Liangpunsakul, Suthat; Joseph Tector, A; Fridell, Jonathan A; Ghabril, Marwan; Lacerda, Marco A; Bourdillon, Charlotte; Shen, Changyu; Kwo, Paul Y

    2014-06-01

    Limited data regarding the optimal risk assessment strategy for evaluating candidates for orthotopic liver transplantation (OLT) exist. Our center has adopted a policy of performing cardiac catheterization (CATH) in patients with predefined risk factors, and this is followed by percutaneous coronary intervention (PCI) when it is indicated, even in the presence of negative stress test findings. The aim of this single-center, retrospective study of all patients who underwent OLT between 2000 and 2010 was to assess the effect of our policy on cardiovascular (CV) complications and survival rates after OLT. Data, including 1-year all-cause and CV mortality, postoperative myocardial infarctions (MIs), and frequencies of CATH and PCI, were abstracted. The study was divided into 3 subperiods to reflect the changes in policy over this period: (A) 2000-2004, (B) 2005-2008, and (C) 2009-2010. One thousand two hundred twenty-one patients underwent OLT between 2000 and 2010. The rate of catheterization increased during the 3 time periods (P?

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

    SciTech Connect

    Johnson, T.G.; Jenkins, A.; Scrivani, J.A.; Foreman, J.M.

    1997-07-01

    In 1995, roundwood output from Virginia`s forests totaled more than 455 million cubic feet, 4 percent more than in 1992. Mill byproducts generated from primary manufacturers increased 3 percent to 167 million cubic feet. Almost 97 percent of the plant residues were used primarily for fuel and fiber products. Saw logs were the leading roundwood product at 213 million cubic feet; pulpwood ranked second at 201 million cubic feet; composite panels were third at 21 million cubic feet. The number of primary processing plants declined from 311 in 1992 to 289 in 1995. Total receipts increased 3 percent to almost 485 million cubic feet.

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

    SciTech Connect

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

    1997-06-01

    In 1995, roundwood output from North Carolina`s forests totaled 833 million cubic feet, 2 percent less than in 1994. Mill byproducts generated from primary manufacturers increased 1 percent to 301 million cubic feet. Almost all plant residues were used primarily for fuel and fiber products. Saw logs were the leading roundwood product at 398 million cubic feet; pulpwood ranked second at 332 million cubic feet; veneer logs were third at 66 million cubic feet. The number of primary processing plants declined from 322 in 1994 to 320 in 1995. Total receipts declined 4 percent to under 743 million cubic feet.

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

    SciTech Connect

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

    1996-03-01

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

  17. South Carolina's timber industry: An assessment of timber product output and use, 1991. Forest Service resource bulletin

    SciTech Connect

    Johnson, T.G.; Davenport, E.L.

    1993-05-01

    In 1991, roundwood output from South Carolina's forests totaled 508 million cubic feet, down 13 percent from 1989. Mill byproducts generated from primary processors declined an equal rate to 170 million cubic feet. Almost 100 percent of the residues were used, mostly for fuel and fiber products. Pulpwood remained the leading roundwood product at 250 million cubic feet; saw logs was second with 203 million cubic feet; veneer production was third at 52 million cubic feet. One hundred and eight mills were operating in 1991, nine fewer than in 1989.

  18. Assessing Cardiac Injury in Mice with Dual Energy-microCT, 4D-microCT and microSPECT Imaging Following Partial-Heart Irradiation

    PubMed Central

    Lee, Chang-Lung; Min, Hooney; Befera, Nicholas; Clark, Darin; Qi, Yi; Das, Shiva; Johnson, G. Allan; Badea, Cristian T.; Kirsch, David G.

    2014-01-01

    Purpose To develop a mouse model of cardiac injury following partial-heart irradiation (PHI) and test whether DE-microCT and 4D-microCT can be used to assess cardiac injury after PHI to complement myocardial perfusion imaging using microSPECT. Methods and Materials To study cardiac injury from tangent field irradiation in mice, we used a small-field biological irradiator to deliver a single dose of 12 Gy x-rays to approximately one-third of the left ventricle (LV) of Tie2Cre; p53FL/+ and Tie2Cre; p53FL/? mice, where one or both alleles of p53 are deleted in endothelial cells. Four and 8 weeks after irradiation, mice were injected with gold and iodinated nanoparticle-based contrast agents, and imaged with DE-microCT and 4D-microCT to evaluate myocardial vascular permeability and cardiac function, respectively. Additionally, the same mice were imaged with microSPECT to assess myocardial perfusion. Results After PHI with tangent fields, DE-microCT scans showed a time-dependent increase in accumulation of gold nanoparticles (AuNp) in the myocardium of Tie2Cre; p53FL/? mice. In Tie2Cre; p53FL/? mice, extravasation of AuNp was observed within the irradiated LV, whereas in the myocardium of Tie2Cre; p53FL/+ mice, AuNp were restricted to blood vessels. In addition, data from DE-microCT and microSPECT showed a linear correlation (R2=0.97) between the fraction of the LV that accumulated AuNp and the fraction of LV with a perfusion defect. Furthermore, 4D-microCT scans demonstrated that PHI caused Tie2Cre; p53FL/? mice to develop a markedly decreased ejection fraction, and higher end-diastolic and end-systolic volumes, which were associated with compensatory cardiac hypertrophy of the heart that was not irradiated. Conclusions Our results show that DE-microCT and 4D-microCT with nanoparticle-based contrast agents are novel imaging approaches complementary to microSPECT to non-invasively assess the change in myocardial vascular permeability and cardiac function of mice that develop myocardial injury after PHI. PMID:24521682

  19. Cardiac vulnerability assessment from electrical microvariability of high-resolution electrocardiogram

    Microsoft Academic Search

    H. A. Kestler; J. Wöhrle; M. Höher

    2000-01-01

    Patients susceptible to malignant arrhythmias often have an increased beat-to-beat variation of the T-wave of the electrocardiogram.\\u000a Variability analysis of the T-wave is increasingly used for non-invasive risk assessment. The aim of this study is to evaluate\\u000a intra-QRS beat-to-beat signal variation and to compare it to ST-T variation. The beat-to-beat, microvolt variation of the\\u000a QRS and the ST-T segment from

  20. Technology insight: hand-carried ultrasound cardiac assessment--evolution, not revolution.

    PubMed

    Kimura, Bruce J; DeMaria, Anthony N

    2005-04-01

    Hand-carried ultrasound devices can enhance the art of bedside physical examination by increasing diagnostic accuracy, detecting disease at an earlier stage, and improving triage and referral of patients. Although limitations of device cost and portability can be overcome with technologic advances, the shortage of standardized imaging and training opportunities now needs to be addressed to move the technique forward. Cardiologists are the best-qualified subspecialists to design and teach a simplified training program for bedside use of hand-carried ultrasound devices to assess the cardiovascular system. PMID:16265486

  1. Effect of a Cognitive Aid on Adherence to Perioperative Assessment and Management Guidelines for the Cardiac Evaluation of Non-Cardiac Surgical Patients

    PubMed Central

    Bridges, Kathryn H; Stiegler, Marjorie P; Schell, Randall M; DiLorenzo, Amy N; Ehrenfeld, Jesse M; Nietert, Paul J; McEvoy, Matthew D

    2014-01-01

    BACKGROUND The 2007 American College of Cardiologists/American Heart Association Guidelines on Perioperative Cardiac Evaluation and Care for Noncardiac Surgery is the standard for perioperative cardiac evaluation. Recent work has shown residents and anesthesiologists do not apply these guidelines when tested. This research hypothesized that a decision support tool would improve adherence to this consensus guideline. METHODS Anesthesiology residents at 4 training programs participated in an unblinded prospective randomized cross-over trial in which they completed two tests covering clinical scenarios. One quiz was completed from memory and one with the aid of an electronic decision support tool. Performance was evaluated by overall score (% correct), number of incorrect answers with possibly increased cost or risk of care, and the amount of time required to complete the quizzes both with and without the cognitive aid. The primary outcome was the proportion of correct responses attributable to the use of the decision support tool. RESULTS All anesthesiology residents at four institutions were recruited and 111 residents participated. Use of the decision support tool resulted in a 25% improvement in adherence to guidelines compared to memory alone (p<0.0001), and participants made 77% fewer incorrect responses that would have resulted in increased costs. Use of the tool was associated with a 3.4-minute increase in time to complete the test (p<0.001). CONCLUSIONS Use of an electronic decision support tool significantly improved adherence to the guidelines as compared to memory alone. The decision support tool also prevented inappropriate management steps possibly associated with increased healthcare costs. PMID:24705442

  2. Assessment of cardiac ischaemia and viability: role of cardiovascular magnetic resonance

    PubMed Central

    Schwitter, Juerg; Arai, Andrew E.

    2011-01-01

    Over the past years, cardiovascular magnetic resonance (CMR) has proven its efficacy in large clinical trials, and consequently, the assessment of function, viability, and ischaemia by CMR is now an integrated part of the diagnostic armamentarium in cardiology. By combining these CMR applications, coronary artery disease (CAD) can be detected in its early stages and this allows for interventions with the goal to reduce complications of CAD such as infarcts and subsequently chronic heart failure (CHF). As the CMR examinations are robust and reproducible and do not expose patients to radiation, they are ideally suited for repetitive studies without harm to the patients. Since CAD is a chronic disease, the option to monitor CAD regularly by CMR over many decades is highly valuable. Cardiovascular magnetic resonance also progressed recently in the setting of acute coronary syndromes. In this situation, CMR allows for important differential diagnoses. Cardiovascular magnetic resonance also delineates precisely the different tissue components in acute myocardial infarction such as necrosis, microvascular obstruction (MVO), haemorrhage, and oedema, i.e. area at risk. With these features, CMR might also become the preferred tool to investigate novel treatment strategies in clinical research. Finally, in CHF patients, the versatility of CMR to assess function, flow, perfusion, and viability and to characterize tissue is helpful to narrow the differential diagnosis and to monitor treatment. PMID:21398645

  3. Monte Carlo simulations to assess differentiation between defects in cardiac SPECT

    NASA Astrophysics Data System (ADS)

    Chrysanthou-Baustert, I.; Parpottas, Y.; Demetriadou, O.; Christofides, S.; Yiannakkaras, Ch; Kaolis, D.; Wasilewska-Radwanska, M.

    2011-09-01

    Differentiating between various types of lesions in nuclear cardiology is a challenge. This work assesses the level of differentiation achievable between various low contrast lesions, as encountered in nuclear cardiology. The parameters investigated are defect extend, defect thickness and perfusion reduction of the defect. The images have been obtained through Monte Carlo Simulations with the program SIMIND. Results show that acceptable size resolution is obtained for defects with an extend over 25×25mm. When thickness and perfusion reduction are both unknown, the imaging results are confounding. In this work, thickness and perfusion reduction cannot be differentiated. If one of the variables is known (thickness or perfusion reduction), imaging results can differentiate between the other unknown variable.

  4. A dynamic thorax phantom for the assessment of cardiac and respiratory motion correction in PET/MRI: A preliminary evaluation

    NASA Astrophysics Data System (ADS)

    Fieseler, Michael; Kugel, Harald; Gigengack, Fabian; Kösters, Thomas; Büther, Florian; Quick, Harald H.; Faber, Cornelius; Jiang, Xiaoyi; Schäfers, Klaus P.

    2013-02-01

    Respiratory and cardiac motion are a known source of image degradation and quantification impairment in positron emission tomography (PET). In this study we use near-realistic PET/MRI data acquired using a custom-built human torso phantom capable of simulating respiratory and cardiac motion. We demonstrate that a significant reduction in motion-induced artifacts in PET data is possible using MR-derived motion estimates.

  5. Association of atheroma as assessed by intraoperative transoesophageal echocardiography with long-term mortality in patients undergoing cardiac surgery

    Microsoft Academic Search

    Senthil K. Thambidorai; Sukaina J. Jaffer; Tushar K. Shah; William J. Stewart; Allan L. Klein; Michael S. Lauer

    2007-01-01

    Aims To determine whether the presence and severity of aortic atheroma predict long-term all-cause mortality among patients undergoing cardiac surgery. Methods and results We followed 8581 patients who underwent cardiac surgery and had routine intra- operative transoesophageal echocardiography for 2.8 years (range 0.06-6.0 years). Data regarding mul- tiple potential confounders were prospectively collected and electronically recorded. There were 2878 (34%)

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

    SciTech Connect

    Johnson, T.G.

    1998-01-01

    This report contains the findings of a 1995 canvass of all primary wood-using plants in the Southeast and presents changes in product output and residue use since 1992. It complements the Forest Inventory and Analysis periodic inventory of volume and removals from the timberland in Southeastern States. The canvass was conducted to determine the amount and source of wood receipts and annual timber product drain by county in 1995 and to determine interstate and cross-regional movement of industrial roundwood. Only primary wood-using mills were canvassed. Primary mills are those that process roundwood in log or bolt form or as chipped roundwood. Examples of industrial roundwood products are saw logs, pulpwood, veneer logs, poles, and logs used for composite board products.

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

    SciTech Connect

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

    2013-12-01

    The plant alkaloid ibogaine has promising anti-addictive properties. Albeit not licenced as a therapeutic drug, and despite hints that ibogaine may perturb the heart rhythm, this alkaloid is used to treat drug addicts. We have recently reported that ibogaine inhibits human ERG (hERG) potassium channels at concentrations similar to the drugs affinity for several of its known brain targets. Thereby the drug may disturb the heart's electrophysiology. Here, to assess the drug's cardiac ion channel profile in more detail, we studied the effects of ibogaine and its congener 18-Methoxycoronaridine (18-MC) on various cardiac voltage-gated ion channels. We confirmed that heterologously expressed hERG currents are reduced by ibogaine in low micromolar concentrations. Moreover, at higher concentrations, the drug also reduced human Na{sub v}1.5 sodium and Ca{sub v}1.2 calcium currents. Ion currents were as well reduced by 18-MC, yet with diminished potency. Unexpectedly, although blocking hERG channels, ibogaine did not prolong the action potential (AP) in guinea pig cardiomyocytes at low micromolar concentrations. Higher concentrations (? 10 ?M) even shortened the AP. These findings can be explained by the drug's calcium channel inhibition, which counteracts the AP-prolonging effect generated by hERG blockade. Implementation of ibogaine's inhibitory effects on human ion channels in a computer model of a ventricular cardiomyocyte, on the other hand, suggested that ibogaine does prolong the AP in the human heart. We conclude that therapeutic concentrations of ibogaine have the propensity to prolong the QT interval of the electrocardiogram in humans. In some cases this may lead to cardiac arrhythmias. - Highlights: • We study effects of anti-addiction drug ibogaine on ionic currents in cardiomyocytes. • We assess the cardiac ion channel profile of ibogaine. • Ibogaine inhibits hERG potassium, sodium and calcium channels. • Ibogaine’s effects on ion channels are a potential source of cardiac arrhythmias. • 18-Methoxycoronaridine has a lower affinity for cardiac ion channels than ibogaine.

  8. Assessing the long-term performance of terrestrial ecosystem models in northeastern United States: linking model structure and output

    NASA Astrophysics Data System (ADS)

    Liu, Y.; Matthes, J. H.; Moore, D. J.; Dietze, M.; Arellano, A. F.; Dawson, A.; Fox, A. M.; Goring, S. J.; McLachlan, J. S.; Montane, F.; Moreno, G.; Poulter, B.; Quaife, T. L.; Ricciuto, D. M.; Schaefer, K. M.; Steinkamp, J.; Williams, J. W.; Team, P.

    2014-12-01

    Terrestrial biosphere models are being used to forecast ecosystem response to future climate change. However, the predictions of these models do not agree, and their ability to accurately represent decadal- and longer-scale ecological processes has rarely been tested. Here we investigate how the structure of the terrestrial biosphere models affects their ability to accurately simulate vegetation dynamics over the past 1000 years. Six models and model variations are involved, including the Ecosystem Demography 2 model (ED2), the Community Land Model (CLM4.0, CLM4.5, CLM4.5-dynamic vegetation), and the Lund-Postdam-Jena models (LPJ-GUESS and LPJ-wsl). Using common paleoclimatic drivers and modeling protocols, we simulated vegetation changes in the northeastern US with these models for the past 1000 years. We compared the model outputs with paleoecological/historical benchmark datasets (paleo-vegetation data reconstructed from fossil pollen records and pre-EuroAmerican vegetation data from the Public Land Survey and Town Proprietor Surveys) to evaluate model performance. We characterized the models based on how they represented photosynthesis, water relations, soil, biogeochemical cycling, and vegetation dynamics. Models with similar structures behaved more similarly over time; we found that model attributes of both fast (e.g. photosynthesis) and slow processes (e.g. vegetation dynamics) affect model long-term predictions. However, the effect of model attributes varies among regions and across time. In addition to model structure, parameter uncertainty among models also appears to contribute to the differences in model output. We are currently working on assimilating paleoecological data into a subset of the terrestrial biosphere models to constrain the key model parameters and state variables, and in turn, to better evaluate the effect of model structure alone on model performance.

  9. Cardiac risk stratification and protection.

    PubMed

    Halub, Meghan E; Sidwell, Richard A

    2015-04-01

    The goal of preoperative cardiac evaluation is to screen for undiagnosed cardiac disease or to find evidence of known conditions that are poorly controlled to allow management that reduces the risk of perioperative cardiac complications. A careful history and physical examination combined with the procedure-specific risk is the cornerstone of this assessment. This article reviews a brief history of prior cardiac risk stratification indexes, explores current practice guidelines by the American College of Cardiology and the American Heart Association Task Force, reviews current methods for preoperative evaluation, discusses revascularization options, and evaluates perioperative medication recommendations. PMID:25814103

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

    SciTech Connect

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

    2011-03-15

    Purpose: In the present era of cone-beam CT scanners, the use of the standardized CTDI{sub 100} as a surrogate of the idealized CTDI is strongly discouraged and, consequently, so should be the use of the dose-length product (DLP) as an estimate of the total energy imparted to the patient. However, the DLP is still widely used as a reference quantity to normalize the effective dose for a given scan protocol mainly because the CTDI{sub 100} is an easy-to-measure quantity. The aim of this article is therefore to describe a method for radiation dose assessment in large cone-beam single axial scans, which leads to a straightforward estimation of the total energy imparted to the patient. The authors developed a method accessible to all medical physicists and easy to implement in clinical practice in an attempt to update the bridge between CT dosimetry and the estimation of the effective dose. Methods: The authors used commercially available material and a simple mathematical model. The method described herein is based on the dosimetry paradigm introduced by the AAPM Task Group 111. It consists of measuring the dose profiles at the center and the periphery of a long body phantom with a commercial solid-state detector. A weighted dose profile is then calculated from these measurements. To calculate the CT dosimetric quantities analytically, a Gaussian function was fitted to the dose profile data. Furthermore, the Gaussian model has the power to condense the z-axis information of the dose profile in two parameters: The single-scan central dose, f(0), and the width of the profile, {sigma}. To check the energy dependence of the solid-state detector, the authors compared the dose profiles to measurements made with a small volume ion chamber. To validate the overall method, the authors compared the CTDI{sub 100} calculated analytically to the measurement made with a 100 mm pencil ion chamber. Results: For the central and weighted dose profiles, the authors found a good agreement between the measured dose profile data and the fitted Gaussian functions. The solid-state detector had no energy dependence--within the energy range of interest--and the analytical model succeeded in reproducing the absolute dose values obtained with the pencil ion chamber. For the case of large cone-beam single axial scans, the quantity that better characterizes the total energy imparted to the patient is the weighted dose profile integral (DPI{sub w}). The DPI{sub w} can be easily determined from the two parameters that define the Gaussian functions: f(0) and {sigma}. The authors found that the DLP underestimated the total energy imparted to the patient by more than 20%. The authors also found that the calculated CT dosimetric quantities were higher than those displayed on the scanner console. Conclusions: The authors described and validated a method to assess radiation dose in large cone-beam single axial scans. This method offers a simple and more accurate estimation of the total energy imparted to the patient, thus offering the possibility to update the bridge between CT dosimetry and the estimation of the effective dose for cone-beam CT examinations in radiology, nuclear medicine, and radiation therapy.

  11. Assessment of phase based dose modulation for improved dose efficiency in cardiac CT on an anthropomorphic motion phantom

    NASA Astrophysics Data System (ADS)

    Budde, Adam; Nilsen, Roy; Nett, Brian

    2014-03-01

    State of the art automatic exposure control modulates the tube current across view angle and Z based on patient anatomy for use in axial full scan reconstructions. Cardiac CT, however, uses a fundamentally different image reconstruction that applies a temporal weighting to reduce motion artifacts. This paper describes a phase based mA modulation that goes beyond axial and ECG modulation; it uses knowledge of the temporal view weighting applied within the reconstruction algorithm to improve dose efficiency in cardiac CT scanning. Using physical phantoms and synthetic noise emulation, we measure how knowledge of sinogram temporal weighting and the prescribed cardiac phase can be used to improve dose efficiency. First, we validated that a synthetic CT noise emulation method produced realistic image noise. Next, we used the CT noise emulation method to simulate mA modulation on scans of a physical anthropomorphic phantom where a motion profile corresponding to a heart rate of 60 beats per minute was used. The CT noise emulation method matched noise to lower dose scans across the image within 1.5% relative error. Using this noise emulation method to simulate modulating the mA while keeping the total dose constant, the image variance was reduced by an average of 11.9% on a scan with 50 msec padding, demonstrating improved dose efficiency. Radiation dose reduction in cardiac CT can be achieved while maintaining the same level of image noise through phase based dose modulation that incorporates knowledge of the cardiac reconstruction algorithm.

  12. Cardiac Risk Assessment

    MedlinePLUS

    ... the formation of plaques in arteries. Cholesterol/HDL ratio — calculated by dividing the HDL-C result into the total cholesterol result; a higher ratio indicates a higher risk of heart disease while ...

  13. Nonlinear analysis of heart rate variability to assess the reaction of ewe fetuses undergoing fetal cardiac surgery.

    PubMed

    Del Gaudio, Costantino; Carotti, Adriano; Grigioni, Mauro; Morbiducci, Umberto

    2012-05-01

    Fetal cardiac surgery (FCS) represents a challenging issue for the in utero treatment of congenital heart defects. However, FCS has still not gained the sufficient reliability for clinical practice due to an incompletely elucidated fetal stress response. For example, blood sampling can contribute to its onset, leading to fetoplacental unit dysfunction, one of the main causes of failure of the surgical procedure. In order to address this issue, the role of the autonomic control system during an experimental procedure of cardiac bypass on ewe fetuses was investigated by means of recurrence quantification analysis (RQA), a well-recognized method for the analysis of nonlinear systems. RQA was applied to time series extracted from fetal arterial pressure recordings before and after the cardiac bypass established by means of an extracorporeal circuit, including an axial blood pump, and taking advantage of the capability of the placenta to work as a natural oxygenator. Statistically significant correlations were found among RQA-based metrics and fetal blood gas data, suggesting the possibility to infer the clinical status of the fetus starting from its hemodynamic signals.This study shows the relevance of RQA as a complementary tool for the monitoring of the fetal status during cardiac bypass. PMID:22669589

  14. Methods for reducing biases and errors in regional photochemical model outputs for use in emission reduction and exposure assessments

    NASA Astrophysics Data System (ADS)

    Porter, P. Steven; Rao, S. Trivikrama; Hogrefe, Christian; Gego, Edith; Mathur, Rohit

    2015-07-01

    In the United States, regional-scale photochemical models are being used to design emission control strategies needed to meet the relevant National Ambient Air Quality Standards (NAAQS) within the framework of the attainment demonstration process. Previous studies have shown that the current generation of regional photochemical models can have large biases and errors in simulating absolute levels of pollutant concentrations. Studies have also revealed that regional air quality models were not always accurately reproducing even the relative changes in ozone air quality stemming from changes in emissions. This paper introduces four approaches to adjust for model bias and errors in order to provide greater confidence for their use in estimating future concentrations as well as using modeled pollutant concentrations in exposure assessments. The four methods considered here are a mean and variance (MV) adjustment, temporal component decomposition (TC) adjustment of modeled concentrations, and two variants of cumulative distribution function (CDF) mapping. These methods were compared against each other as well as against unadjusted model concentrations and a version of the relative response approach based on unadjusted model predictions. The analysis uses ozone concentrations simulated by the Community Multiscale Air Quality (CMAQ) model for the northeastern United States domain for the years 1996-2005. Ensuring that base case conditions are adequately represented through the combined use of observations and model simulations is shown to result in improved estimates of future air quality under changing emissions and meteorological conditions.

  15. Cardiac Catheterization

    MedlinePLUS

    ... done during a cardiac catheterization include: closing small holes inside the heart repairing leaky or narrow heart ... bandage. It's normal for the site to be black and blue, red, or slightly swollen for a ...

  16. Cardiac Sarcoidosis

    MedlinePLUS

    ... do at National Jewish Health? We provide comprehensive cardiology evaluation and consultation and non-invasive cardiac testing. ... the whole person, not just the disease. Our cardiology team works with healthcare providers from all areas ...

  17. Cardiac catheterization and angiography, 3d Ed

    SciTech Connect

    Grossman, W.

    1986-01-01

    This textbook was first published in 1974 and subsequently revised in 1980. The current edition, in seven parts and 33 chapters, has been extensively rewritten, and new chapters have been added that present recently developed techniques. The references have been updated to 1985. The purpose of this work is to provide a concise description of the major techniques employed in cardiac catheterization and angiography. Part 1 deals with the history, general principles, and practice of cardiac catheterization and angiography. In part 2, various techniques of cardiac catheterization are discussed and compared. In part 3, techniques for the determination of cardiac output, pressure, resistance, valve area, and shunt flow are described. Part 4 deals briefly with coronary angiography, cardiac ventriculography, pulmonary angiography, and aortography. In part 5, techniques for evaluating cardiac function and intracardiac electrophysiology are presented. The characteristic hemodynamic and angiographic abnormalities in specific disorders are described in part 6. Part 7 deals with special catheter techniques.

  18. Nuclear cardiac

    SciTech Connect

    Slutsky, R.; Ashburn, W.L.

    1982-01-01

    The relationship between nuclear medicine and cardiology has continued to produce a surfeit of interesting, illuminating, and important reports involving the analysis of cardiac function, perfusion, and metabolism. To simplify the presentation, this review is broken down into three major subheadings: analysis of myocardial perfusion; imaging of the recent myocardial infarction; and the evaluation of myocardial function. There appears to be an increasingly important relationship between cardiology, particularly cardiac physiology, and nuclear imaging techniques. (KRM)

  19. Feasibility of cognitive functional assessment in cardiac arrest survivors using an abbreviated laptop-based neurocognitive battery.

    PubMed

    Iannacone, Stephen; Leary, Marion; Esposito, Emily C; Ruparel, Kosha; Savitt, Adam; Mott, Allison; Richard, Jan A; Gur, Ruben C; Abella, Benjamin S

    2014-09-01

    Cardiac arrest survivors exhibit varying degrees of neurological recovery even in the setting of targeted temperature management (TTM) use, ranging from severe impairments to making a seemingly full return to neurologic baseline function. We sought to explore the feasibility of utilizing a laptop-based neurocognitive battery to identify more subtle cognitive deficits in this population. In a convenience sample of cardiac arrest survivors discharged with a cerebral performance category (CPC) of 1, we evaluated the use of a computerized neurocognitive battery (CNB) in this group compared to a healthy control normative population. The CNB was designed to test 11 specific neurocognitive domains, including such areas as working memory and spatial processing. Testing was scored for both accuracy and speed. In a feasibility convenience sample of 29 cardiac arrest survivors, the mean age was 52.9±16.7 years; 12 patients received postarrest TTM and 17 did not receive TTM. Patients tolerated the battery well and performed at normative levels for both accuracy and speed on most of the 11 domains, but showed reduced accuracy of working memory and speed of spatial memory with large magnitudes (>1 SD), even among those receiving TTM. Across all domains, including those using speed and accuracy, 7 of the 29 subjects (24%) achieved statistically significant scores lower from the normative population in two or more domains. In this population of CPC 1 cardiac arrest survivors, a sensitive neurocognitive battery was feasible and suggests that specific cognitive deficits can be detected compared to a normative population, despite CPC 1 designation. Such testing might allow improved measurement of outcomes following TTM interventions in future trials. PMID:25010524

  20. The use of pupillometry in the assessment of cardiac autonomic function in elite different type trained athletes

    Microsoft Academic Search

    Antonia Kaltsatou; Evangelia Kouidi; Dimitrios Fotiou; Pantazis Deligiannis

    The aim of the present study was to evaluate cardiac autonomic function by pupillometry in male athletes. Fifteen elite endurance-\\u000a (END) and eleven power-trained (POWER) athletes and fifteen sedentary individuals (CONTROL) were studied. All subjects underwent\\u000a three pupillometric measurements: at rest, peak exercise testing and recovery phase. The pupillometric indices studied were:\\u000a baseline pupil radius (R1), minimum pupil radius (R2),

  1. Assessment of the Turkish Version of the King's Stool Chart for Evaluating Stool Output and Diarrhea Among Patients Receiving Enteral Nutrition.

    PubMed

    Sucu Dag, Gülten; Dicle, Aklime; Saka, Osman; Whelan, Kevin

    2015-01-01

    The purpose of this study was to evaluate the reliability and validity of the Turkish version of the King's Stool Chart (KSC-Tr) in patients receiving enteral nutrition. In total, 212 stool samples taken from 25 patients receiving enteral nutrition during 393 sick days in two intensive care units were assessed using the KSC-Tr. Overall, 110 of 212 stools (51.9%) were characterized as liquid and 111 of 212 stools (52.4%) were characterized as less than 100 g. The daily stool score of patients receiving antibiotics, a risk factor for diarrhea, was higher (mean = 13.6; SD = 10.1) than that of patients not receiving antibiotics (mean = 9.3; SD = 5.0) (p = .001). Diarrhea occurred on more days when patients received antibiotics (62/329; 18.8%) than on days when they did not (3/64; 4.7%) (p = .005). Interobserver agreement of two independent nurses' assessments on 44 stool samples was examined and was good for both stool consistency (?= 0.76) and stool weight (?= 0.75). In the intensive care unit, the KSC-Tr can be used as a valid and reliable tool for monitoring diarrhea and stool output in patients receiving enteral nutrition. PMID:25946479

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

    PubMed

    Koenig, Xaver; Kovar, Michael; Rubi, Lena; Mike, Agnes K; Lukacs, Peter; Gawali, Vaibhavkumar S; Todt, Hannes; Hilber, Karlheinz; Sandtner, Walter

    2013-12-01

    The plant alkaloid ibogaine has promising anti-addictive properties. Albeit not licensed as a therapeutic drug, and despite hints that ibogaine may perturb the heart rhythm, this alkaloid is used to treat drug addicts. We have recently reported that ibogaine inhibits human ERG (hERG) potassium channels at concentrations similar to the drugs affinity for several of its known brain targets. Thereby the drug may disturb the heart's electrophysiology. Here, to assess the drug's cardiac ion channel profile in more detail, we studied the effects of ibogaine and its congener 18-Methoxycoronaridine (18-MC) on various cardiac voltage-gated ion channels. We confirmed that heterologously expressed hERG currents are reduced by ibogaine in low micromolar concentrations. Moreover, at higher concentrations, the drug also reduced human Nav1.5 sodium and Cav1.2 calcium currents. Ion currents were as well reduced by 18-MC, yet with diminished potency. Unexpectedly, although blocking hERG channels, ibogaine did not prolong the action potential (AP) in guinea pig cardiomyocytes at low micromolar concentrations. Higher concentrations (? 10 ?M) even shortened the AP. These findings can be explained by the drug's calcium channel inhibition, which counteracts the AP-prolonging effect generated by hERG blockade. Implementation of ibogaine's inhibitory effects on human ion channels in a computer model of a ventricular cardiomyocyte, on the other hand, suggested that ibogaine does prolong the AP in the human heart. We conclude that therapeutic concentrations of ibogaine have the propensity to prolong the QT interval of the electrocardiogram in humans. In some cases this may lead to cardiac arrhythmias. PMID:23707769

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

    PubMed Central

    Koenig, Xaver; Kovar, Michael; Rubi, Lena; Mike, Agnes K.; Lukacs, Peter; Gawali, Vaibhavkumar S.; Todt, Hannes; Hilber, Karlheinz; Sandtner, Walter

    2013-01-01

    The plant alkaloid ibogaine has promising anti-addictive properties. Albeit not licenced as a therapeutic drug, and despite hints that ibogaine may perturb the heart rhythm, this alkaloid is used to treat drug addicts. We have recently reported that ibogaine inhibits human ERG (hERG) potassium channels at concentrations similar to the drugs affinity for several of its known brain targets. Thereby the drug may disturb the heart's electrophysiology. Here, to assess the drug's cardiac ion channel profile in more detail, we studied the effects of ibogaine and its congener 18-Methoxycoronaridine (18-MC) on various cardiac voltage-gated ion channels. We confirmed that heterologously expressed hERG currents are reduced by ibogaine in low micromolar concentrations. Moreover, at higher concentrations, the drug also reduced human Nav1.5 sodium and Cav1.2 calcium currents. Ion currents were as well reduced by 18-MC, yet with diminished potency. Unexpectedly, although blocking hERG channels, ibogaine did not prolong the action potential (AP) in guinea pig cardiomyocytes at low micromolar concentrations. Higher concentrations (? 10 ?M) even shortened the AP. These findings can be explained by the drug's calcium channel inhibition, which counteracts the AP-prolonging effect generated by hERG blockade. Implementation of ibogaine's inhibitory effects on human ion channels in a computer model of a ventricular cardiomyocyte, on the other hand, suggested that ibogaine does prolong the AP in the human heart. We conclude that therapeutic concentrations of ibogaine have the propensity to prolong the QT interval of the electrocardiogram in humans. In some cases this may lead to cardiac arrhythmias. PMID:23707769

  4. Predicting cardiac complications in patients undergoing non-cardiac surgery

    Microsoft Academic Search

    Allan S. Detsky; Howard B. Abrams; John R. McLaughlin; Daniel J. Drucker; Zion Sasson; Nancy Johnston; J. Gerald Scott; Nicholas Forbath; Joseph R. Hilliard

    1986-01-01

    The authors prospectively studied 455 consecutive patients referred to the general medical consultation service for cardiac\\u000a risk assessment prior to non-cardiac surgery, in order to validate a previously derived multifactorial index in their clinical\\u000a setting. They also tested a version of the index that they had modified to reflect factors they believed to be important.\\u000a For patients undergoing major surgery,

  5. Progression of cardiac allograft vascular disease as assessed by serial intravascular ultrasound: correlation to immunological and non-immunological risk factors

    PubMed Central

    Pethig, K; Klauss, V; Heublein, B; Mudra, H; Westphal, A; Weber, C; Theisen, K; Haverich, A

    2000-01-01

    OBJECTIVE—To characterise the severity and progression of cardiac allograft vascular disease (CAVD) in a large patient cohort, and to evaluate possible immunological and non-immunological risk factors for progression.?DESIGN—A prospective observational study using intravascular ultrasound.?SETTING—Two university hospitals.?PATIENTS AND MAIN OUTCOME MEASURES—Changes in focal plaque, lumen, and total vessel area (worst site method) were assessed at baseline and after 12.1 (2.8) months (mean (SD)) of follow up in a cohort of 96 patients (79 male, 17 female; mean age 48.7 (9.6) years; time post-transplant 26.0 (32.4) months).?RESULTS—Overall, the mean (SD) intimal index of worst sites increased by 6.7 (8.8)%. The increase in the first 12 months was 7.5 (9.4)%, v 5.9 (8.0)% after the first year (NS). Analysing immunological and non-immunological risk factors (age, underlying disease, sex, donor age, immunosuppression, cytomegalovirus, rejection episodes, cholesterol), low density lipoprotein (LDL) cholesterol was found to be the most important predictor of severe progression (as defined by an increase in intimal index of ? 15% (p = 0.01).?CONCLUSIONS—Progression of CAVD is characterised by a continuing increase in intimal hyperplasia, especially within the first year after heart transplantation. LDL cholesterol is an important predictor of major progression.???Keywords: heart transplantation; cardiac allograft vasculopathy; intravascular ultrasound PMID:11040007

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

    NASA Astrophysics Data System (ADS)

    Baptista, M.; Teles, P.; Cardoso, G.; Vaz, P.

    2014-11-01

    Over the last decade, there was a substantial increase in the number of interventional cardiology procedures worldwide, and the corresponding ionizing radiation doses for both the medical staff and patients became a subject of concern. Interventional procedures in cardiology are normally very complex, resulting in long exposure times. Also, these interventions require the operator to work near the patient and, consequently, close to the primary X-ray beam. Moreover, due to the scattered radiation from the patient and the equipment, the medical staff is also exposed to a non-uniform radiation field that can lead to a significant exposure of sensitive body organs and tissues, such as the eye lens, the thyroid and the extremities. In order to better understand the spatial variation of the dose and dose rate distributions during an interventional cardiology procedure, the dose distribution around a C-arm fluoroscopic system, in operation in a cardiac cath lab at Portuguese Hospital, was estimated using both Monte Carlo (MC) simulations and dosimetric measurements. To model and simulate the cardiac cath lab, including the fluoroscopic equipment used to execute interventional procedures, the state-of-the-art MC radiation transport code MCNPX 2.7.0 was used. Subsequently, Thermo-Luminescent Detector (TLD) measurements were performed, in order to validate and support the simulation results obtained for the cath lab model. The preliminary results presented in this study reveal that the cardiac cath lab model was successfully validated, taking into account the good agreement between MC calculations and TLD measurements. The simulated results for the isodose curves related to the C-arm fluoroscopic system are also consistent with the dosimetric information provided by the equipment manufacturer (Siemens). The adequacy of the implemented computational model used to simulate complex procedures and map dose distributions around the operator and the medical staff is discussed, in view of the optimization principle (and the associated ALARA objective), one of the pillars of the international system of radiological protection.

  7. Cardiac amyloidosis.

    PubMed

    Kingman, A; Pereira, N L

    2001-05-01

    Cardiac amyloidosis should be considered in a patient with heart failure, who is normotensive with decreased left ventricular systolic function and marked left ventricular hypertrophy by echocardiogram and has decreased voltage by ECG. Furthermore, when the diagnosis of cardiac amyloid is made, it is important to classify the subtype of disease to be able to offer appropriate treatment. Contrary to traditional belief that the prognosis for patients with amyloidosis is dismal, some forms of this disease are curable and other forms are characterized by slow progression of disease. PMID:11381776

  8. Cardiac sarcoidosis

    PubMed Central

    Smedema, J.P.; Zondervan, P.E.; van Hagen, P.; ten Cate, F.J.; Bresser, P.; Doubell, A.F.; Pattynama, P.; Hoogsteden, H.C.; Balk, A.H.M.M.

    2002-01-01

    Sarcoidosis is a multi-system granulomatous disorder of unknown aetiology. Symptomatic cardiac involvement occurs in approximately 5% of patients. The prevalence of sarcoidosis in the Netherlands is unknown, but estimated to be approximately 20 per 100,000 population (3200 patients). We report on five patients who presented with different manifestations of cardiac sarcoidosis, and give a brief review on the current management of this condition. Magnetic Resonance Imaging (MRI) can be of great help in diagnosing this condition as well as in the follow-up of the response to therapy. ImagesFigure 1Figure 2Figure 3Figure 4Figure 5Figure 6 PMID:25696121

  9. Comparisons of four categories of waste recycling in China's paper industry based on physical input-output life-cycle assessment model.

    PubMed

    Liang, Sai; Zhang, Tianzhu; Xu, Yijian

    2012-03-01

    Waste recycling for paper production is an important component of waste management. This study constructs a physical input-output life-cycle assessment (PIO-LCA) model. The PIO-LCA model is used to investigate environmental impacts of four categories of waste recycling in China's paper industry: crop straws, bagasse, textile wastes and scrap paper. Crop straw recycling and wood utilization for paper production have small total intensity of environmental impacts. Moreover, environmental impacts reduction of crop straw recycling and wood utilization benefits the most from technology development. Thus, using crop straws and wood (including wood wastes) for paper production should be promoted. Technology development has small effects on environmental impacts reduction of bagasse recycling, textile waste recycling and scrap paper recycling. In addition, bagasse recycling and textile waste recycling have big total intensity of environmental impacts. Thus, the development of bagasse recycling and textile waste recycling should be properly limited. Other pathways for reusing bagasse and textile wastes should be explored and evaluated. Moreover, imports of scrap paper should be encouraged to reduce large indirect impacts of scrap paper recycling on domestic environment. PMID:22100716

  10. Assessment of global cardiac uptake of Radiolabeled Iron Oxide Nanoparticles in Apolipoprotein E-Deficient Mice: implications for imaging cardiovascular inflammation

    PubMed Central

    de Barros, André Luís Branco; Chacko, Ann-Marie; Mikitsh, John L.; Zaki, Ajlan Al; Salavati, Ali; Saboury, Babak; Tsourkas, Andrew; Alavi, Abass

    2014-01-01

    Purpose Atherosclerosis is a leading cause of death in industrialized countries and is characterized by the accumulation of lipids and inflammatory cells, including macrophages, in blood vessel walls. Therefore, the ability to image macrophages could help identify plaques that are precursors of acute thrombotic events. Previous research has shown that long-circulating, nanoparticles could be used to detect macrophages within atherosclerotic plaques of the aorta. By conducting this study, we investigated whether global cardiac uptake of radiolabeled nanoparticles could allow assessment of total macrophage burden in the coronary arteries. Procedures Dextran-coated Iron Oxide Nanoparticles (IONPs) were labeled with iodine-125 via Bolton-Hunter (SHPP) method. IONPs were characterized by means of dynamic light scattering and transmission electronic microscopy. Biodistribution studies were performed in healthy and atherosclerotic mice. Additionally, digital autoradiography of hearts from both healthy and atherosclerotic mice was performed to assess regional and global atherosclerotic burden. Results The [125I]IONPs exhibited high radiolabel stability and long blood circulation, which eventually led to high heart uptake in apoE ?/? mice when compared with healthy controls. Furthermore, digital autoradiography showed substantially enhanced emission of signals from the hearts of atherosclerotic mice, while no or minimal cardiac signals were detected in healthy mice. Conclusions This preparation showed adequate physical-chemical properties for in vivo studies, such as small size (~30 nm), good radiolabel stability, and long circulation time. There was also significant accumulation in the heart of apoE?/? mice compared with that of healthy control animals. These findings suggest that radiolabeled dextran-coated iron oxide nanoparticles may have potential to become a useful tool to detect macrophages in the atherosclerosis plaques of coronary arteries; however, these preliminary findings should be confirmed by further studies in a larger scale in various atherosclerosis models. PMID:24297372

  11. Bayesian Sensitivity Analysis of a Cardiac Cell Model Using a Gaussian Process Emulator

    PubMed Central

    Chang, Eugene T Y; Strong, Mark; Clayton, Richard H

    2015-01-01

    Models of electrical activity in cardiac cells have become important research tools as they can provide a quantitative description of detailed and integrative physiology. However, cardiac cell models have many parameters, and how uncertainties in these parameters affect the model output is difficult to assess without undertaking large numbers of model runs. In this study we show that a surrogate statistical model of a cardiac cell model (the Luo-Rudy 1991 model) can be built using Gaussian process (GP) emulators. Using this approach we examined how eight outputs describing the action potential shape and action potential duration restitution depend on six inputs, which we selected to be the maximum conductances in the Luo-Rudy 1991 model. We found that the GP emulators could be fitted to a small number of model runs, and behaved as would be expected based on the underlying physiology that the model represents. We have shown that an emulator approach is a powerful tool for uncertainty and sensitivity analysis in cardiac cell models. PMID:26114610

  12. Cardiac mechanics: Physiological, clinical, and mathematical considerations

    NASA Technical Reports Server (NTRS)

    Mirsky, I. (editor); Ghista, D. N.; Sandler, H.

    1974-01-01

    Recent studies concerning the basic physiological and biochemical principles underlying cardiac muscle contraction, methods for the assessment of cardiac function in the clinical situation, and mathematical approaches to cardiac mechanics are presented. Some of the topics covered include: cardiac ultrastructure and function in the normal and failing heart, myocardial energetics, clinical applications of angiocardiography, use of echocardiography for evaluating cardiac performance, systolic time intervals in the noninvasive assessment of left ventricular performance in man, evaluation of passive elastic stiffness for the left ventricle and isolated heart muscle, a conceptual model of myocardial infarction and cardiogenic shock, application of Huxley's sliding-filament theory to the mechanics of normal and hypertrophied cardiac muscle, and a rheological modeling of the intact left ventricle. Individual items are announced in this issue.

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

    PubMed

    Flori, Alessandra; Liserani, Matteo; Frijia, Francesca; Giovannetti, Giulio; Lionetti, Vincenzo; Casieri, Valentina; Positano, Vincenzo; Aquaro, Giovanni Donato; Recchia, Fabio A; Santarelli, Maria Filomena; Landini, Luigi; Ardenkjaer-Larsen, Jan Henrik; Menichetti, Luca

    2015-05-01

    Dissolution-dynamic nuclear polarization (dissolution-DNP) for magnetic resonance (MR) spectroscopic imaging has recently emerged as a novel technique for noninvasive studies of the metabolic fate of biomolecules in vivo. Since acetate is the most abundant extra- and intracellular short-chain fatty acid, we focused on [1-(13) C]acetate as a promising candidate for a chemical probe to study the myocardial metabolism of a beating heart. The dissolution-DNP procedure of Na[1-(13) C]acetate for in vivo cardiac applications with a 3 T MR scanner was optimized in pigs during bolus injection of doses of up to 3 mmol. The Na[1-(13) C]acetate formulation was characterized by a liquid-state polarization of 14.2% and a T1Eff in vivo of 17.6 ± 1.7 s. In vivo Na[1-(13) C]acetate kinetics displayed a bimodal shape: [1-(13) C]acetyl carnitine (AcC) was detected in a slice covering the cardiac volume, and the signal of (13) C-acetate and (13) C-AcC was modeled using the total area under the curve (AUC) for kinetic analysis. A good correlation was found between the ratio AUC(AcC)/AUC(acetate) and the apparent kinetic constant of metabolic conversion, from [1-(13) C]acetate to [1-(13) C]AcC (kAcC ), divided by the AcC longitudinal relaxation rate (r1 ). Our study proved the feasibility and the limitations of administration of large doses of hyperpolarized [1-(13) C]acetate to study the myocardial conversion of [1-(13) C]acetate in [1-(13) C]acetyl-carnitine generated by acetyltransferase in healthy pigs. Copyright © 2014 John Wiley & Sons, Ltd. PMID:25201079

  14. Potential and natural output

    Microsoft Academic Search

    Giorgio Primiceri; Alejandro Justiniano

    2009-01-01

    We estimate a DSGE model with imperfectly competitive products and labor markets, and sticky prices and wages. We use the model to back out two counterfactual objects: potential output, i.e. the level of output that would prevail under perfect competition, and natural output, i.e. the level of output that would prevail with flexible prices and wages. We find that potential

  15. Cardiac cone-beam CT

    SciTech Connect

    Manzke, Robert [University of London (King's College) (United Kingdom)]. E-mail: robert.manzke@philips.com

    2005-10-15

    This doctoral thesis addresses imaging of the heart with retrospectively gated helical cone-beam computed tomography (CT). A thorough review of the CT reconstruction literature is presented in combination with a historic overview of cardiac CT imaging and a brief introduction to other cardiac imaging modalities. The thesis includes a comprehensive chapter about the theory of CT reconstruction, familiarizing the reader with the problem of cone-beam reconstruction. The anatomic and dynamic properties of the heart are outlined and techniques to derive the gating information are reviewed. With the extended cardiac reconstruction (ECR) framework, a new approach is presented for the heart-rate-adaptive gated helical cardiac cone-beam CT reconstruction. Reconstruction assessment criteria such as the temporal resolution, the homogeneity in terms of the cardiac phase, and the smoothness at cycle-to-cycle transitions are developed. Several reconstruction optimization approaches are described: An approach for the heart-rate-adaptive optimization of the temporal resolution is presented. Streak artifacts at cycle-to-cycle transitions can be minimized by using an improved cardiac weighting scheme. The optimal quiescent cardiac phase for the reconstruction can be determined automatically with the motion map technique. Results for all optimization procedures applied to ECR are presented and discussed based on patient and phantom data. The ECR algorithm is analyzed for larger detector arrays of future cone-beam systems throughout an extensive simulation study based on a four-dimensional cardiac CT phantom. The results of the scientific work are summarized and an outlook proposing future directions is given. The presented thesis is available for public download at www.cardiac-ct.net.

  16. Using MERRA, AMIP II, CMIP5 Outputs to Assess Actual and Potential Building Climate Zone Change and Variability From the Last 30 Years Through 2100

    NASA Astrophysics Data System (ADS)

    Stackhouse, P. W.; Westberg, D. J.; Hoell, J. M., Jr.; Chandler, W.; Zhang, T.

    2014-12-01

    In the US, residential and commercial building infrastructure combined consumes about 40% of total energy usage and emits about 39% of total CO2emission (DOE/EIA "Annual Energy Outlook 2013"). Thus, increasing the energy efficiency of buildings is paramount to reducing energy costs and emissions. Building codes, as used by local and state enforcement entities are typically tied to the dominant climate within an enforcement jurisdiction classified according to various climate zones. These climates zones are based upon a 30-year average of local surface observations and are developed by DOE and ASHRAE (formerly known as the American Society of Hearting, Refrigeration and Air-Conditioning Engineers). A significant shortcoming of the methodology used in constructing such maps is the use of surface observations (located mainly near airports) that are unequally distributed and frequently have periods of missing data that need to be filled by various approximation schemes. This paper demonstrates the usefulness of using NASA's Modern Era Retrospective-analysis for Research and Applications (MERRA) atmospheric data assimilation to derive the ASHRAE climate zone maps and then using MERRA to define the last 30 years of variability in climate zones. These results show that there is a statistically significant increase in the area covered by warmer climate zones and some tendency for a reduction of area in colder climate zones that require longer time series to confirm. Using the uncertainties of the basic surface temperature and precipitation parameters from MERRA as determined by comparison to surface measurements, we first compare patterns and variability of ASHRAE climate zones from MERRA relative to present day climate model runs from AMIP simulations to establish baseline sensitivity. Based upon these results, we assess the variability of the ASHRAE climate zones according to CMIP runs through 2100 using an ensemble analysis that classifies model output changes by percentiles. Estimates of statistical significance are then compared to original model variability during the AMIP period. This work quantifies and tests for significance the changes seen in the various US regions that represent a potential contribution by NASA to the ongoing National Climate Assessment.

  17. Cardiac Arrhythmias

    Microsoft Academic Search

    William J. Bonney; Ra-id Abdulla

    \\u000a An initial and crucial step in managing any child with a cardiac arrhythmia is to determine the hemodynamic stability of the\\u000a child. A healthy pink color of skin\\/mucosa, brisk capillary refill, good peripheral pulses, normal blood pressure, and absence\\u000a of respiratory distress are all reassuring signs that the hemodynamic status of the child is normal or near normal. Stable\\u000a hemodynamics

  18. Working Group Report Extracorporeal circulation in non-cardiac surgery

    Microsoft Academic Search

    Dietrich E. Birnbaum

    Summary Tradition and experience of cardiopulmonary bypass in the hand of cardiac surgeons led to several spin-offs of this extracorporeal technique. Acute organ support is realized for situations of failing cardiac output, circulatory arrest respectively, of pulmonary failure and of drowning. Extracorporeal circulation is a promising adjunct to aim in better surgical technique and treatment in neurosurgery, thoracic aortic surgery,

  19. Fuzzy Controller for Automatic Drug Infusion in Cardiac Patients

    Microsoft Academic Search

    M. Logesh Kumar; R. Harikumar; A. Keerthi Vasan; V. K. Sudhaman

    2009-01-01

    Control of mean arterial blood pressure and cardiac output is highly desirable in certain operative procedures and in post cardiac operation. This paper emphasizes on a fuzzy controller to control these two variables within the present limits by administering three drugs dopamine, Sodium Nitro Prusside and Phenylephrine which perform the function of increasing heartbeat rate, decreases, increases blood pressure respectively.

  20. Partial scan artifact reduction (PSAR) for the assessment of cardiac perfusion in dynamic phase-correlated CT

    SciTech Connect

    Stenner, Philip; Schmidt, Bernhard; Bruder, Herbert; Allmendinger, Thomas; Haberland, Ulrike; Flohr, Thomas; Kachelriess, Marc [Institute of Medical Physics, Henkestrasse 91, 91052 Erlangen (Germany); Siemens AG, Healthcare Sector, Siemensstrasse 1, 91301 Forchheim (Germany); Institute of Medical Physics, Henkestrasse. 91, 91052 Erlangen (Germany)

    2009-12-15

    Purpose: Cardiac CT achieves its high temporal resolution by lowering the scan range from 2{pi} to {pi} plus fan angle (partial scan). This, however, introduces CT-value variations, depending on the angular position of the {pi} range. These partial scan artifacts are of the order of a few HU and prevent the quantitative evaluation of perfusion measurements. The authors present the new algorithm partial scan artifact reduction (PSAR) that corrects a dynamic phase-correlated scan without a priori information. Methods: In general, a full scan does not suffer from partial scan artifacts since all projections in [0, 2{pi}] contribute to the data. To maintain the optimum temporal resolution and the phase correlation, PSAR creates an artificial full scan p{sub n}{sup AF} by projectionwise averaging a set of neighboring partial scans p{sub n}{sup P} from the same perfusion examination (typically N{approx_equal}30 phase-correlated partial scans distributed over 20 s and n=1,...,N). Corresponding to the angular range of each partial scan, the authors extract virtual partial scans p{sub n}{sup V} from the artificial full scan p{sub n}{sup AF}. A standard reconstruction yields the corresponding images f{sub n}{sup P}, f{sub n}{sup AF}, and f{sub n}{sup V}. Subtracting the virtual partial scan image f{sub n}{sup V} from the artificial full scan image f{sub n}{sup AF} yields an artifact image that can be used to correct the original partial scan image: f{sub n}{sup C}=f{sub n}{sup P}-f{sub n}{sup V}+f{sub n}{sup AF}, where f{sub n}{sup C} is the corrected image. Results: The authors evaluated the effects of scattered radiation on the partial scan artifacts using simulated and measured water phantoms and found a strong correlation. The PSAR algorithm has been validated with a simulated semianthropomorphic heart phantom and with measurements of a dynamic biological perfusion phantom. For the stationary phantoms, real full scans have been performed to provide theoretical reference values. The improvement in the root mean square errors between the full and the partial scans with respect to the errors between the full and the corrected scans is up to 54% for the simulations and 90% for the measurements. Conclusions: The phase-correlated data now appear accurate enough for a quantitative analysis of cardiac perfusion.

  1. Neurological complications of cardiac surgery.

    PubMed

    McDonagh, David L; Berger, Miles; Mathew, Joseph P; Graffagnino, Carmelo; Milano, Carmelo A; Newman, Mark F

    2014-05-01

    As increasing numbers of elderly people undergo cardiac surgery, neurologists are frequently called upon to assess patients with neurological complications from the procedure. Some complications mandate acute intervention, whereas others need longer term observation and management. A large amount of published literature exists about these complications and guidance on best practice is constantly changing. Similarly, despite technological advances in surgical intervention and modifications in surgical technique to make cardiac procedures safer, these advances often create new avenues for neurological injury. Accordingly, rapid and precise neurological assessment and therapeutic intervention rests on a solid understanding of the evidence base and procedural variables. PMID:24703207

  2. Plasma alpha natriuretic peptide in cardiac impairment

    Microsoft Academic Search

    A M Richards; J G Cleland; G Tonolo; G D McIntyre; B J Leckie; H J Dargie; S G Ball; J I Robertson

    1986-01-01

    Regional plasma alpha human atrial natriuretic peptide concentrations were measured, and their relation to intracardiac pressures assessed, in an unselected series of 45 patients undergoing diagnostic cardiac catheterisation. Arteriovenous gradients in plasma concentrations of alpha human atrial natriuretic peptide were consistent with its cardiac secretion and its clearance by the liver and kidneys. Plasma concentrations of the peptide in the

  3. Cardiac repolarization analysis using the surface electrocardiogram

    Microsoft Academic Search

    Esther Pueyo; Juan Pablo Martínez; Pablo Laguna

    2009-01-01

    Sudden cardiac death (SCD) is a challenging health problem in the western world. Analysis of cardiac repolarization from the electrocardiogram (ECG) provides valuable information for stratifying patients according to their risk of suffering from arrhythmic events that could end in SCD, as well as for assessing efficacy of antiarrhythmic therapies. In this paper, we start by exploring the cellular basis

  4. Sudden Cardiac Arrest: ECG Repolarization after Resuscitation

    E-print Network

    Paris-Sud XI, Université de

    ) is a relatively common situation associated with a high mortality rate (1, 2). The main cause of OHCA is known associated with sudden cardiac death (7, 8). The aim of our study was to assess the value of different-cardiac etiology (i.e. trauma, sepsis, acute respiratory failure. . .); pregnancy, and/or known terminal illness

  5. Cardiac Vagal Regulation and Early Peer Status

    ERIC Educational Resources Information Center

    Graziano, Paulo A.; Keane, Susan P.; Calkins, Susan D.

    2007-01-01

    A sample of 341 5 1/2-year-old children participating in an ongoing longitudinal study was the focus of a study on the relation between cardiac vagal regulation and peer status. To assess cardiac vagal regulation, resting measures of respiratory sinus arrhythmia (RSA) and RSA change (suppression) to 3 cognitively and emotionally challenging tasks…

  6. [Possibilities of dopplerography in assessment of functional state of the heart in patients with arterial hypertension with impaired diastolic cardiac function].

    PubMed

    Alekseeva, O A; Alekhin, M N; Sidorenko, B A

    2009-01-01

    The search for reliable Dopplerographic markers of incipient diastolic cardiac failure became especially actual in recent years. We examined 71 patients with II degree arterial hypertension (AH) with Dopplerographical signs of diastolic left ventricular (LV) dysfunction. For the assessment of severity of diastolic dysfunction we carried out complex Dopplerographic evaluation of maximal velocities of transmitral blood flow and motion of fibrous annulus of the mitral valve (MV). We revealed relationships between standard parameters of transmitral flow, Doppler visualization of tissues, and tolerance to physical effort. We found moderate negative correlation between exercise tolerance and maximal velocity of movement of lateral part of MV fibrous annulus E' (r=-0.4, p=<0.001), E/E' ratio (r=-0.65, p=<0.001). E/E' ratio had the strongest linear relationship with exercise tolerance. We showed that combined assessment of velocity of early LV diastolic filling and velocity of MV fibrous annulus motion (E/E') was possible in all patients with preserved LV systolic function. In patients with AH without myocardial hypertrophy with incipient LV diastolic dysfunction increase of E/E' > or = 10 allows to suggest lowering of exercise tolerance and might be indicative of early signs of diastolic heart failure. PMID:19772501

  7. Cardiac alterations induced by a fish-catching diving competition.

    PubMed

    Gargne, O; Joulia, F; Golé, Y; Coulange, M; Bessereau, J; Fontanari, P; Desruelle, A-V; Gavarry, O; Boussuges, A

    2012-06-01

    Cardiac changes induced by repeated breath-hold diving were investigated after a fish-catching diving competition. Eleven healthy subjects carried out repeated breath-hold dives at a mean maximal depth of 20 ± 2.7 msw (66 ± 9 fsw) during 5 h. One hour after the competition, the body mass loss was -1.7 ± 0.5 kg. Most of the breath-hold divers suffered from cold and although the core temperature remained normal, a decrease in cutaneous temperature was recorded in the extremities. Systolic blood pressure was reduced in both upper and lower limbs. Heart rate was unchanged, but left ventricular (LV) stroke volume was reduced leading to a decrease in cardiac output (-20%). Left atrial and LV diameters were significantly decreased. LV filling was assessed on a trans-mitral profile. An increase in the contribution of the atrial contraction to LV filling was observed. Right cavity diameters were increased. The cardiac autonomic alterations were in favor of sympathetic hyperactivity. After a fish-catching diving competition in cold water, alterations suggesting dehydration, contraction in plasma volume and sympathetic hyperactivity were observed. Furthermore, enlargements of right cavities were in favor of right ventricular strains. Repeated apnea and swimming in cold water may account for these alterations. PMID:20738824

  8. A mathematical model for the assessment of hemodynamic parameters using quantitative contrast echocardiography

    Microsoft Academic Search

    Xucai Chen; Karl Q. Schwarz; Daniel Phillips; Sherry D. Steinmetz; Reinhard Schlief

    1998-01-01

    A mathematical model for the assessment of hemodynamic parameters using quantitative echocardiography is presented. The method involves the intravenous injection of an ultrasonic echo contrast agent. The relative enhancement of the backscattered ultrasound intensity is measured as a function of time (the time-intensity curve). From this measurement, the volume flow rate (cardiac output) and the mixing volume are calculated. Relevant

  9. Pre-hospital cardiac arrest: room for improvement

    Microsoft Academic Search

    T. J. Hodgetts; T. Brown; P. Driscoll; J. Hanson

    1995-01-01

    Objective: To audit the outcome from pre-hospital cardiac arrest managed by ambulance personnel, and to assess their proficiency by analysing the time to initiate basic and advanced cardiac life support, the compliance with national guidelines, and the overall success of resuscitation. Design: A retrospective analysis of ambulance service report forms of pre-hospital cardiac arrests, where active resuscitation was attempted by

  10. Assessment of Long-Term Climate Change Impacts on Agricultural Productivity in Eastern China Using High-Resolution Regional Climate Model Output

    NASA Astrophysics Data System (ADS)

    Chavas, D. R.; Izaurralde, C.; Thomson, A.

    2008-12-01

    Increasing atmospheric greenhouse gas concentrations are expected to induce significant climate change over the next century and beyond, but the impacts on society remain highly uncertain. This work utilizes high-resolution regional climate model output to assess potential climate change impacts on the productivity of five major crops in eastern China: canola, corn, potato, rice, and winter wheat. In addition to determining domain-wide trends, the objective is to identify vulnerable and emergent regions under future climate conditions, defined as having a greater than 10 percent decrease and increase in productivity, respectively. Data from the ICTP RegCM3 regional climate model for baseline (1961-1990) and future (2071-2100) periods under A2 scenario conditions are used as input in the EPIC agro-ecosystem simulation model in the domain [30N, 108E] to [42N, 123E]. Simulations are performed with and without the enhanced CO2 fertilization effect. Results indicate that aggregate potential productivity (i.e. if the crop is grown everywhere) increases 6.5 percent for rice, 8.3 percent for canola, 18.6 percent for corn, 22.9 percent for potato, and 24.9 percent for winter wheat, although with significant spatial variability for each crop. However, absent the enhanced CO2 fertilization effect, potential productivity declines in all cases ranging from 2.5-12 percent. Interannual yield variability remains constant or declines in all cases except rice. Climate variables are found to be more significant drivers of simulated yield changes than changes in soil properties, except in the case of potato production in the northwest where the effects of wind erosion are more significant. Overall, in the future period corn and winter wheat benefit significantly in the North China Plain, rice remains dominant in the southeast and emerges in the northeast, potato and corn yields become viable in the northwest, and potato yields suffer in the southwest with no other crop emerging as a clear beneficiary from among those simulated in this study.

  11. Assessing the early changes of cerebral glucose metabolism via dynamic (18)FDG-PET/CT during cardiac arrest.

    PubMed

    Li, Ying-Qing; Liao, Xiao-Xing; Lu, Jian-Hua; Liu, Rong; Hu, Chun-Lin; Dai, Gang; Zhang, Xiang-Song; Shi, Xin-Chong; Li, Xin

    2015-08-01

    To study the changes of cerebral glucose metabolism (CGM) during the phase of return of spontaneous circulation (ROSC) after cardiac arrest (CA), we used 18-fluorodeoxyglucose-positron emission tomography/computed tomography ((18)FDG-PET/CT) to measure the CGM changes in six beagle canine models. After the baseline (18)FDG-PET/CT was recorded, ventricular fibrillation (VF) was induced for 6 min, followed by close-chest cardiopulmonary resuscitation (CPR) in conjunction with intravenous (IV) administration of epinephrine and external defibrillator shocks until ROSC was achieved, within 30 min. The (18)FDG was recorded prior to intravenous administration at 0 h (baseline), and at 4, 24, and 48 h after CA with ROSC. We evaluated the expression of two key control factors in canine CGM, hexokinase I (HXK I) and HXK II, by immunohistochemistry at the four above mentioned time points. Electrically induced VF of 6 min duration was successfully induced in the dogs. Resuscitation was then performed to maintain blood pressure stability. Serial (18)FDG-PET/CT scans found that the CGM decreased at 4 h after ROSC and remained lower than the baseline even at 48 h. The expression of HXK I and II levels were consistent with the changes in CGM. These data from our present work showed that (18)FDG-PET/CT imaging can be used to detect decreased CGM during CA and was consistent with the results of CMRgl. Furthermore, there were also concomitant changes in the expression of HXK I and HXK II. The decrease in CGM may be an early sign of hyperacute global cerebral ischemia. PMID:25703241

  12. Non-cardiac surgery in patients with prior myocardial revascularization

    Microsoft Academic Search

    Patricia M. Cruchley; Joel A. Kaplan; Carl C. Hug; David Nagle; Rhea Sumpter; Donna Finucane

    1983-01-01

    Patients who had undergone aorto-coronary bypass grafts (ACBG) were assessed\\/or the incidence of cardiac complications in\\u000a the postoperative period following subsequent non-cardiac surgery. One hundred and twenty-one patients had 13 complications\\u000a (11 percent). A significantly higher risk of cardiac complications (27 per cent) was found in patients undergoing non-cardiac\\u000a procedures in the first month after ACBG. This remained higher (17

  13. Rich Tactile Output on Mobile Devices

    Microsoft Academic Search

    Alireza Sahami; Paul Holleis; Albrecht Schmidt; Jonna Häkkilä

    2008-01-01

    In this paper we assess the potential of rich tactile notifications on mobile phones. Many mobile phone users use vibration output for various types of notification on their phone. Currently, tactile output in phones is limited to one single actuator that can potentially present patterns based on different vibration intensity over time. To explore the possible design space, we conducted

  14. Segmentation of myocardial boundaries in tagged cardiac MRI using active contours: a

    E-print Network

    Histace, Aymeric

    Segmentation of myocardial boundaries in tagged cardiac MRI using active contours: a gradient: aymeric.histace@ensea.fr Abstract. The non invasive assessment of cardiac function is of first importance to evaluate the local cardiac motion: Tagged Cardiac MRI is one of them. This protocol generates on Short

  15. Cardiac magnetic resonance imaging assessment of regional and global left atrial function before and after catheter ablation for atrial fibrillation

    Microsoft Academic Search

    David Nori; Gilbert Raff; Vikesh Gupta; Ralph Gentry; Judith Boura; David E. Haines

    2009-01-01

    Background  Ablation of the left atrium and pulmonary veins antrum (PVAI) can be an effective treatment of atrial fibrillation (AF). However,\\u000a there is discrepancy in the literature regarding the effect extensive ablation has on left atrial (LA) function. We sought\\u000a to evaluate the effect that AF ablation procedures has on global and regional wall motion as assessed by cardiovascular magnetic\\u000a resonance

  16. CD62L (L-Selectin) Shedding for Assessment of Perioperative Immune Sensitivity in Patients Undergoing Cardiac Surgery with Cardiopulmonary Bypass

    PubMed Central

    Erdoes, Gabor; Balmer, Maria L.; Slack, Emma; Kocsis, Istvan; Lehmann, Lutz E.; Eberle, Balthasar; Stüber, Frank; Book, Malte

    2013-01-01

    Objective To investigate the suitability of blood granulocyte and monocyte sensitivity, as measured by the quantity of different agonists required to induce CD62L shedding, for assessment of perioperative immune changes in patients undergoing cardiac surgery with cardiopulmonary bypass. Methods Patients scheduled for aortocoronary bypass grafting or for valve surgery were included in this prospective observational study. Blood samples were drawn before anesthesia induction, directly after surgery and 48 hours after anesthesia induction. We determined the concentration of two different inflammatory stimuli – lipoteichoic acid (LTA) and tumor necrosis factor alpha (TNF) - required to induce shedding of 50% of surface CD62L from blood granulocytes and monocytes. In parallel monocyte surface human leukocyte antigen (HLA)-DR, and plasma interleukin (IL)-8, soluble (s)CD62L, soluble (s)Toll-like receptor (TLR)-2 and ADAM17 quantification were used to illustrate perioperative immunomodulation. Results 25 patients were enrolled. Blood granulocytes and monocytes showed decreased sensitivity to the TLR 2/6 agonist Staphylococcus aureus LTA immediately after surgery (p?=?0.001 and p?=?0.004 respectively). In contrast, granulocytes (p?=?0.01), but not monocytes (p?=?0.057) displayed a decreased postoperative sensitivity to TNF. We confirmed the presence of a systemic inflammatory response and a decreased immune sensitivity in the post-surgical period by measuring significant increases in the perioperative plasma concentration of IL-8 (p?0.001) and sTLR (p?=?0.004), and decreases in monocyte HLA-DR (p<0.001), plasma sCD62L (p?0.001). In contrast, ADAM17 plasma levels did not show significant differences over the observation period (p?=?0.401). Conclusions Monitoring granulocyte and monocyte sensitivity using the “CD62L shedding assay” in the perioperative period in cardiac surgical patients treated with the use of cardiopulmonary bypass reveals common changes in sensitivity to TLR2/6 ligands and to TNF stimulus. Further long-term follow-up studies will address the predictive value of these observations for clinical purposes. PMID:23301018

  17. Diagnostic accuracy of combined cardiac troponin and copeptin assessment for early rule-out of myocardial infarction: a systematic review and meta-analysis

    PubMed Central

    Raskovalova, Tatiana; Twerenbold, Raphael; Collinson, Paul O; Keller, Till; Bouvaist, Hélène; Folli, Christian; Giavarina, Davide; Lotze, Ulrich; Eggers, Kai M; Dupuy, Anne-Marie; Chenevier-Gobeaux, Camille; Meune, Christophe; Maisel, Alan; Mueller, Christian

    2014-01-01

    Aims: This systematic review aimed to investigate the diagnostic accuracy of combined cardiac troponin (cTn) and copeptin assessment in comparison to cTn alone for early rule-out of acute myocardial infarction (AMI). Methods: Primary studies were eligible if they evaluated diagnostic accuracy for cTn with and without copeptin in patients with symptoms suggestive of AMI. AMI was defined according to the universal definition, using detection of cTn as a marker for myocardial necrosis. Eligible studies were identified by searching electronic databases (Medline, EMBASE, Science Citation Index Expanded, CINAHL, Pascal, and Cochrane) from inception to March 2013, reviewing conference proceedings and contacting field experts and the copeptin manufacturer. Results: In 15 studies totalling 8740 patients (prevalence of AMI 16%), adding copeptin improved the sensitivity of cTn assays (from 0.87 to 0.96, p=0.003) at the expense of lower specificity (from 0.84 to 0.56, p<0.001). In 12 studies providing data for 6988 patients without ST-segment elevation, the summary sensitivity and specificity estimates were 0.95 (95% CI 0.89 to 0.98) and 0.57 (95% CI 0.49 to 0.65) for the combined assessment of cTn and copeptin. When a high-sensitivity cTnT assay was used in combination with copeptin, the summary sensitivity and specificity estimates were 0.98 (95% CI 0.96 to 1.00) and 0.50 (95% CI 0.42 to 0.58). Conclusion: Despite substantial between-study heterogeneity, this meta-analysis demonstrates that copeptin significantly improves baseline cTn sensitivity. Management studies are needed to establish the effectiveness and safety of measuring copeptin in combination with high-sensitivity cTnT for early rule-out of AMI without serial testing. PMID:24562800

  18. Cardiac aquaporins.

    PubMed

    Rutkovskiy, Arkady; Valen, Guro; Vaage, Jarle

    2013-11-01

    Aquaporins are a group of proteins with high-selective permeability for water. A subgroup called aquaglyceroporins is also permeable to glycerol, urea and a few other solutes. Aquaporin function has mainly been studied in the brain, kidney, glands and skeletal muscle, while the information about aquaporins in the heart is still scarce. The current review explores the recent advances in this field, bringing aquaporins into focus in the context of myocardial ischemia, reperfusion, and blood osmolarity disturbances. Since the amount of data on aquaporins in the heart is still limited, examples and comparisons from better-studied areas of aquaporin biology have been used. The human heart expresses aquaporin-1, -3, -4 and -7 at the protein level. The potential roles of aquaporins in the heart are discussed, and some general phenomena that the myocardial aquaporins share with aquaporins in other organs are elaborated. Cardiac aquaporin-1 is mostly distributed in the microvasculature. Its main role is transcellular water flux across the endothelial membranes. Aquaporin-4 is expressed in myocytes, both in cardiac and in skeletal muscle. In addition to water flux, its function is connected to the calcium signaling machinery. It may play a role in ischemia-reperfusion injury. Aquaglyceroporins, especially aquaporin-7, may serve as a novel pathway for nutrient delivery into the heart. They also mediate toxicity of various poisons. Aquaporins cannot influence permeability by gating, therefore, their function is regulated by changes of expression-on the levels of transcription, translation (by microRNAs), post-translational modification, membrane trafficking, ubiquitination and subsequent degradation. Studies using mice genetically deficient for aquaporins have shown rather modest changes in the heart. However, they might still prove to be attractive targets for therapy directed to reduce myocardial edema and injury caused by ischemia and reperfusion. PMID:24158693

  19. Input-Output Analysis

    Microsoft Academic Search

    Ronald E. Miller; Peter D. Blair

    This 2009 edition of Ronald Miller and Peter Blair's classic textbook is an essential reference for students and scholars in the input-output research and applications community. The book has been fully revised and updated to reflect important developments in the field since its original publication. New topics covered include SAMs (and extended input-output models) and their connection to input-output data,

  20. Role of breathing in cardiac performance: experimental and mathematical models

    NASA Astrophysics Data System (ADS)

    Tran, Binh Q.; Hoffman, Eric A.

    1999-05-01

    Due to the close proximity of the heart and lungs within a closed chest environment, we expect breathing to affect various cardiac performance parameters and hence cardiac output. We present an integrative approach to study heart-lung interactions, combining a mathematical formulation of the circulation system with imaging techniques using echo-planar magnetic resonance imaging (EPI) and dynamic x-ray CT (EBCT). We hypothesize that appropriate synchronization of mechanical ventilation to cardiac-cycle specific events can improve cardiac function, i.e. stroke volume (SV) and cardiac output (CO). Computational and experimental results support the notion that heart-lung interaction, leading to altered cardiac output associated with inspiration/expiration, is not directly associated with lung inflation/deflation and thus is felt to be more influenced by pleural pressure changes. The mathematical model of the circulation demonstrates the importance of cardiac-cycle specific timing of ventilation on cardiac function and matches with experimentally observed relationships found in animal models studied via EBCT and human studies using EPI. Results show that positive pressure mechanical ventilation timed to systolic events may increase SV and CO by up to 30%, mainly by increased filling of the ventricles during diastole. Similarly, negative pressure (spontaneous) respiration has its greatest effect on ventricular diastolic filling. Cardiac-gated mechanical ventilation may provide sufficient cardiac augmentation to warrant further investigation as a minimally-invasive technique for temporary cardiac assist. Through computational modeling and advanced imaging protocols, we were able to uniquely study heart-lung interactions within the intact milieu of the never-invaded thorax.

  1. Diagnostic pediatric cardiac catheterization: Experience of a tertiary care pediatric cardiac centre

    PubMed Central

    Kumar, Prabhat; Joshi, Vidya Sagar; Madhu, P.V.

    2013-01-01

    Background Cardiac catheterization was considered gold standard for confirmation of diagnosis and analyzing various management issues in congenital heart diseases. In spite of development of various non invasive tools for investigation of cardiac disorders diagnostic catheterization still holds an important place in pediatric patients. Methods 300 consecutive diagnostic cardiac catheterization performed since April 2007 were included in this study. The study was undertaken to evaluate the profile of patients undergoing diagnostic cardiac catheterization, its results, assess its safety and its contribution toward solving various management issues. Result & Conclusion Children who underwent cardiac catheterization ranged in weight from 1.6 kg to 35 kg, with their age range 0 day–12 years. The information obtained was of great importance for further management in over 90% cases. The procedure of cardiac cath is invasive, still it was proved to be quite safe even in smallest baby. PMID:24623940

  2. Posterior left atrial–esophageal relationship throughout the cardiac cycle

    Microsoft Academic Search

    Jasbir Sra; David Krum; Angela Malloy; Atul Bhatia; Ryan Cooley; Zalmen Blanck; Anwer Dhala; Alfred J. Anderson; Masood Akhtar

    2006-01-01

    Background  Radiofrequency energy delivered throughout the cardiac cycle has the potential to cause thermal injury to the esophagus if the anatomical relationship between the posterior left atrium and the esophagus changes during cardiac motion.Objective  To assess the posterior left atrial–esophageal relationship throughout the cardiac cycle.Methods  In this study, the anatomical relationship between the posterior left atrium and the esophagus was assessed throughout the

  3. Cardiac Output, Rates of Change and Accumulation: Unit Overview

    NSDL National Science Digital Library

    Created by Illuminations: Resources for Teaching Mathematics, this unit plan contains four lessons that explore rates of change and accumulation in the context of the amount of blood being pumped by the heart. The measurement is done from a discrete perspective, but can be easily generalized to a continuous perspective that includes use of integral calculus. The individual lessons are titled: make a conjecture, gather data, analyze the data and reflecting on your work. The author states the goal of this lesson as: "[The] rich exploration of rates of change and accumulation in context."

  4. Thermal dilution and ultrasound: alternative techniques for measuring cardiac output.

    PubMed

    1988-01-01

    We evaluated 5 TD CO units, 4 modules and 1 stand-alone, from 5 manufacturers. All units are rated Acceptable. Most of the test results met our accuracy and precision criteria; other results that demonstrated a small margin of error were still clinically useful. The utility of the TD method depends largely on proper technique, as well as the volume and temperature of the injection, number of injections, and the type of probe used. Purchasing decisions should be based primarily on the compatibility of the proposed TD units with existing physiologic monitors and whether a module or a stand-alone unit is more appropriate. PMID:3078918

  5. Reproducibility of linear cardiac output measurement by Doppler ultrasound alone

    Microsoft Academic Search

    F M McLennan; N E Haites; J D Mackenzie; M K Daniel; J M Rawles

    1986-01-01

    Inclusion of a pig aorta in an artificial circulation with pulsed blood flow allowed correlation of minute distance, measured in the aorta by Doppler ultrasound, and absolute blood flow, measured by timed blood-volume collection. The correlation coefficient was 0.99 with a standard error of prediction that was 5.4% of the minute distance predicted at a standard flow rate of 5

  6. Cardiac AAV9 Gene Delivery Strategies in Adult Canines: Assessment by Long-term Serial SPECT Imaging of Sodium Iodide Symporter Expression.

    PubMed

    Moulay, Gilles; Ohtani, Tomohito; Ogut, Ozgur; Guenzel, Adam; Behfar, Atta; Zakeri, Rosita; Haines, Philip; Storlie, Jimmy; Bowen, Lorna; Pham, Linh; Kaye, David; Sandhu, Gurpreet; O'Connor, Michael; Russell, Stephen; Redfield, Margaret

    2015-07-01

    Heart failure is a leading cause of morbidity and mortality, and cardiac gene delivery has the potential to provide novel therapeutic approaches. Adeno-associated virus serotype 9 (AAV9) transduces the rodent heart efficiently, but cardiotropism, immune tolerance, and optimal delivery strategies in large animals are unclear. In this study, an AAV9 vector encoding canine sodium iodide symporter (NIS) was administered to adult immunocompetent dogs via epicardial injection, coronary infusion without and with cardiac recirculation, or endocardial injection via a novel catheter with curved needle and both end- and side-holes. As NIS mediates cellular uptake of clinical radioisotopes, expression was tracked by single-photon emission computerized tomography (SPECT) imaging in addition to Western blot and immunohistochemistry. Direct epicardial or endocardial injection resulted in strong cardiac expression, whereas expression after intracoronary infusion or cardiac recirculation was undetectable. A threshold myocardial injection dose that provides robust nonimmunogenic expression was identified. The extent of transmural myocardial expression was greater with the novel catheter versus straight end-hole needle delivery. Furthermore, the authors demonstrate that cardiac NIS reporter gene expression and duration can be quantified using serial noninvasive SPECT imaging up to 1 year after vector administration. These data are relevant to efforts to develop cardiac gene delivery as heart failure therapy. PMID:25915925

  7. Cardiac Mechanics Evaluated by Speckle Tracking Echocardiography

    PubMed Central

    Abduch, Maria Cristina Donadio; Alencar, Adriano Mesquita; Mathias, Wilson; Vieira, Marcelo Luiz de Campos

    2014-01-01

    Natural myocardial markers, or speckles, originated from constructive and destructive interference of ultrasound in the tissues may provide early diagnosis of myocardial changes and be used in the prediction of some cardiac events. Due to its relatively temporal stability, speckles can be tracked by dedicated software along the cardiac cycle, enabling the analysis of the systolic and diastolic function. They are identified by either conventional 2D grey scale and by 3D echo, conferring independence of the insonation angle, thus allowing assessment of cardiac mechanics in the three spatial planes: longitudinal, circumferential, and radial. The purposes of the present paper are: to discuss the role and the meaning of cardiac strain obtained by speckle tracking during the evaluation of cardiac physiology and to discuss clinical applications of this novel echocardiographic technology. PMID:24844877

  8. Protocol for the China PEACE (Patient-centered Evaluative Assessment of Cardiac Events) retrospective study of coronary catheterisation and percutaneous coronary intervention

    PubMed Central

    Li, Jing; Dharmarajan, Kumar; Li, Xi; Lin, Zhenqiu; Normand, Sharon-Lise T; Krumholz, Harlan M; Jiang, Lixin

    2014-01-01

    Introduction During the past decade, the volume of percutaneous coronary intervention (PCI) in China has risen by more than 20-fold. Yet little is known about patterns of care and outcomes across hospitals, regions and time during this period of rising cardiovascular disease and dynamic change in the Chinese healthcare system. Methods and analysis Using the China PEACE (Patient-centered Evaluative Assessment of Cardiac Events) research network, the Retrospective Study of Coronary Catheterisation and Percutaneous Coronary Intervention (China PEACE-Retrospective CathPCI Study) will examine a nationally representative sample of 11?900 patients who underwent coronary catheterisation or PCI at 55 Chinese hospitals during 2001, 2006 and 2011. We selected patients and study sites using a two-stage cluster sampling design with simple random sampling stratified within economical-geographical strata. A central coordinating centre will monitor data quality at the stages of case ascertainment, medical record abstraction and data management. We will examine patient characteristics, diagnostic testing patterns, procedural treatments and in-hospital outcomes, including death, complications of treatment and costs of hospitalisation. We will additionally characterise variation in treatments and outcomes by patient characteristics, hospital, region and study year. Ethics and dissemination The China PEACE collaboration is designed to translate research into improved care for patients. The study protocol was approved by the central ethics committee at the China National Center for Cardiovascular Diseases (NCCD) and collaborating hospitals. Findings will be shared with participating hospitals, policymakers and the academic community to promote quality monitoring, quality improvement and the efficient allocation and use of coronary catheterisation and PCI in China. Registration details http://www.clinicaltrials.gov (NCT01624896). PMID:24607563

  9. A prospective study of dobutamine stress echocardiography for the assessment of cardiac allograft vasculopathy in pediatric heart transplant recipients.

    PubMed

    Dipchand, Anne I; Bharat, Winston; Manlhiot, Cedric; Safi, Mina; Lobach, Natalia E; McCrindle, Brian W

    2008-08-01

    Transplant CAV is the leading cause of graft loss beyond one yr post-heart transplant. Diagnosis can be challenging and the previous "gold standard," coronary ANG, tends to underestimate disease. The purpose of this study was to relate DSE to ANG for the diagnosis of CAV. Prospective annual DSE at a single centre on all heart transplant patients (1999-2006) were compared with results from routine coronary angiograms. Progression of CAV over time as determined by DSE and ANG and associated factors were sought through logistic regression models adjusted for repeated measures. There were 102 heart transplant patients (54 males) transplanted between 1989 and 2006. Median age at transplant was 17 months (0-16.6 yr). The initial DSE was at a median of 10-months post-transplantation. There was a high correlation between an abnormal DSE and an abnormality on ANG (p = 0.002). There was an increased probability of an abnormal DSE with increasing grade of CAV as assessed by ANG (p < 0.001). Factors associated with an abnormal DSE included older age at transplant (p = 0.04), higher grade of rejection (p = 0.002), higher total cholesterol (p = 0.04), higher LDL (p < 0.05), and older age at the time of DSE (p = 0.002). DSE result was not related to HDL, triglyceride or homocysteine levels, or to steroid or statin use. The probability of an abnormal DSE result increases with increasing angiographic grade of CAV, and thus DSE may be used for initial screening for CAV with ANG reserved for confirmation and grading. Patients transplanted at an older age and those with a greater history of rejection were at higher risk of a positive DSE and may require increased surveillance for CAV. PMID:18363614

  10. Cardiac troponin levels in heart failure.

    PubMed

    Potluri, Srinivasa; Ventura, Hector O; Mulumudi, Mahesh; Mehra, Mandeep R

    2004-01-01

    Congestive heart failure (CHF) is a major cardiovascular disorder that is increasing in incidence, prevalence, and lethality. The prognostic significance of cardiac troponin levels among symptomatic and asymptomatic CHF has attracted recent interest. We sought to assess the significance of cardiac troponins in heart failure. These cardiac markers are associated with decreased left ventricular ejection fraction and poor prognosis in patients with CHF and are related to the severity of heart failure. The mechanism for the release of these markers seems to be from ventricular remodeling, ongoing myocyte degeneration, the presence of coronary artery disease, and reduced coronary reserve. In addition to B-type (brain) natriuretic peptide (BNP), cardiac troponin levels measured in patients admitted to the hospital could help risk-stratify patients and manage them effectively. BNP and cardiac troponins are easy to measure and can be repeated many times to follow patients, without interobserver variability. Theoretically, BNP is a marker of heart failure status and cardiac troponin is a marker of myocyte injury. The first therapeutic goal could be relief of circulatory congestion and lowering of BNP. The second goal could be attenuation of myocyte injury and lowering of cardiac troponins. Measuring and monitoring the levels of both could be highly effective means to reliably stratify the patients into low-, intermediate-, and high-risk groups for cardiac events and progression of heart failure. Furthermore, large-scale trials are necessary to establish them as noninvasive monitoring markers of heart failure and effectiveness of treatment. PMID:14667259

  11. Assessing Right Ventricular Function in Patients with Hypertrophic Cardiomyopathy with Cardiac MRI: Correlation with the New York Heart Function Assessment (NYHA) Classification

    PubMed Central

    Zhang, Shuai; Sun, Jia-yu; Wen, Ling-yi; Xu, Hua-yan; Zhang, Ge

    2014-01-01

    Purpose To determine whether 3.0-T magnetic resonance imaging (MRI) could assess right ventricular (RV) function in patients with hypertrophic cardiomyopathy (HCM), and if this assessment is correlated with the New York Heart Function Assessment (NYHA) classification. Materials and Methods Forty-six patients with HCM and 23 normal individuals were recruited. Left and right ventricular function parameters including end-diastolic and end-systolic volumes (EDV, ESV), stroke volume (SV) and ejection fraction (EF) and dimensions were measured and compared using 3.0-T MRI. RV function parameters between HCM patients and controls were compared using independent sample t tests. A one way ANOVA test with Bonferroni correction was used to determine significant differences among different NYHA groups. Receiver operating characteristic analyses calculated the sensitivity and specificity of RV dysfunction on MRI for the prediction of HCM severity. Results Statistical analysis revealed significant differences of left ventricular (LV) and RV volumetric values and masses between the HCM patients and controls (all p<0.05). Within the HCM group, the simultaneously decreased maximum RVEDD correlated well with the LVEDD (r?=?0.53; p<0.001). The function and dimension parameters among Class I to III were not determined to be significantly different (all p>0.05). However, significant differences between the Class IV and I-III groups (all P<0.0167) indicated that the diastolic and systolic function in both the RV and LV were impaired in Class IV patients. ROC analyses identified the EDV, ESV and EDD of both the LV and RV with a high sensitivity cutoff value to predict the HCM patients with severe heart failure (Class IV) with high sensitivity and specificity. Conclusions RV involvements were comparable to those of LV global function impairments in patients with HCM. The presence of RV dysfunction and decreased dimension on the MRI helped to predict the severe symptomatic HCM with high sensitivity and specificity. PMID:25180597

  12. Visualization of Model Output

    NSDL National Science Digital Library

    Visualization of output from mathematical or statistical models is one of the best ways to introduce introductory geoscience students to the results and behavior of sophisticated models. Example of good sites ...

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

    NASA Technical Reports Server (NTRS)

    Hamilton, D. R.; Sargsyan, A. E.; Garcia, K. M.; Ebert, D.; Feiveson, A. H.; Alferova, I. V.; Dulchavsky, S. A.; Matveev, V. P.; Bogomolov, V. V.; Duncan, J. M.

    2011-01-01

    BACKGROUND: The transition to microgravity eliminates the hydrostatic gradients in the vascular system. The resulting fluid redistribution commonly manifests as facial edema, engorgement of the external neck veins, nasal congestion, and headache. This experiment examined the responses to modified Valsalva and Mueller maneuvers as measured by cardiac and vascular ultrasound in a baseline microgravity steady state, and under the influence of thigh occlusion cuffs (Braslet cuffs). METHODS: Nine International Space Station crewmember subjects (Expeditions 16 - 20) were examined in 15 experiment sessions 101 46 days after launch (mean SD; 33 - 185). 27 cardiac and vascular parameters were obtained under three respiratory conditions (baseline, Valsalva, and Mueller) before and after tightening of the Braslet cuffs for a total of 162 data points per session. The quality of cardiac and vascular ultrasound examinations was assured through remote monitoring and guidance by Investigators from the NASA Telescience Center in Houston, TX, USA. RESULTS: Fourteen of the 81 measured conditions were significantly different with Braslet application and were apparently related to cardiac preload reduction or increase in the venous volume sequestered in the lower extremity. These changes represented 10 of the 27 parameters measured. In secondary analysis, 7 of the 27 parameters were found to respond differently to respiratory maneuvers depending on the presence or absence of thigh compression, with a total of 11 differences. CONCLUSIONS: Acute application of Braslet occlusion cuffs causes lower extremity fluid sequestration and exerts proportionate measurable effects on cardiac performance in microgravity. Ultrasound techniques measuring the hemodynamic effects of thigh cuffs in combination with respiratory maneuvers may serve as an effective tool in determining the volume status of a cardiac or hemodynamically compromised patient in microgravity.

  14. Cardiac arrest management

    Microsoft Academic Search

    Richard V. Aghababian; Gregory Mears; Joseph P. Ornato; Peter J. Kudenchuk

    2001-01-01

    Approximately 1,000 people in the United States suffer cardiac arrest each day, most often as a complication of acute myocardial infarction (AMI) with accompanying ventricular fibrillation or unstable ventricular tachycardia. Increasing the number of patients who survive cardiac arrest and minimizing the clinical sequelae associated with cardiac arrest in those who do survive are the objectives of emergency medical personnel.

  15. Cardiac electrophysiology in mice: a matter of size

    PubMed Central

    Kaese, Sven; Verheule, Sander

    2012-01-01

    Over the last decade, mouse models have become a popular instrument for studying cardiac arrhythmias. This review assesses in which respects a mouse heart is a miniature human heart, a suitable model for studying mechanisms of cardiac arrhythmias in humans and in which respects human and murine hearts differ. Section I considers the issue of scaling of mammalian cardiac (electro) physiology to body mass. Then, we summarize differences between mice and humans in cardiac activation (section II) and the currents underlying the action potential in the murine working myocardium (section III). Changes in cardiac electrophysiology in mouse models of heart disease are briefly outlined in section IV, while section V discusses technical considerations pertaining to recording cardiac electrical activity in mice. Finally, section VI offers general considerations on the influence of cardiac size on the mechanisms of tachy-arrhythmias. PMID:22973235

  16. Role of breathing in cardiac performance: experimental and mathematical models

    Microsoft Academic Search

    Binh Q. Tran; Eric A. Hoffman

    1999-01-01

    Due to the close proximity of the heart and lungs within a closed chest environment, we expect breathing to affect various cardiac performance parameters and hence cardiac output. We present an integrative approach to study heart-lung interactions, combining a mathematical formulation of the circulation system with imaging techniques using echo-planar magnetic resonance imaging (EPI) and dynamic x-ray CT (EBCT). We

  17. Changes in right ventricular structure and function assessed using cardiac magnetic resonance imaging in bosentan-treated patients with pulmonary arterial hypertension.

    PubMed

    Chin, Kelly M; Kingman, Martha; de Lemos, James A; Warner, John J; Reimold, Sharon; Peshock, Ron; Torres, Fernando

    2008-06-01

    Patients with pulmonary arterial hypertension (PAH) usually show improvements in symptoms, exercise capacity, and hemodynamics after treatment with approved medical therapies. This study sought to determine whether improvement in right-sided cardiac function measured using cardiac magnetic resonance imaging would also be seen and whether these changes would correlate with improvement in exercise capacity. Sixteen patients with PAH underwent evaluation at baseline and after 12 months of treatment with bosentan. After treatment, cardiac index, pulmonary vascular resistance, and 6-minute walk distance improved, and there was a trend toward improvement in right ventricular (RV) stroke volume (70 +/- 27 to 81 +/- 30 ml; p = 0.08), but no change in RV ejection fraction (RVEF) or RV end-diastolic volume. Six-minute walk distance improved by 59 m (p <0.05) in the overall cohort and improved more in patients in whom RVEF increased compared with those with stable or decreased RVEF (+98 vs -37 m, respectively; p = 0.01). Three patients died during follow-up, and these patients had significantly lower RVEF and left ventricular end-diastolic volume indexes than surviving patients. In conclusion, these results suggest that cardiac magnetic resonance imaging may have value in determining response to therapy and prognosis in patients with PAH. PMID:18489949

  18. The Relationship of Chronic and Momentary Work Stress to Cardiac Reactivity in Women Managers: Feasibility of a Smart PhoneYAssisted Assessment System

    E-print Network

    Shi, Weisong

    The Relationship of Chronic and Momentary Work Stress to Cardiac Reactivity in Women Managers and momentary work stress on HR reactivity among women managers. Methods: A sample of 40 women managers reported elevated HR only in the context of high chronic stress. Conclusions: Women managers who experience chronic

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

    Microsoft Academic Search

    Gavin R. H. Sandercock; Darren Hardy-Shepherd; David Nunan; David Brodie

    2008-01-01

    Heart rate variability estimates cardiac autonomic modulation, but the relationship between habitual physical activity and heart rate variability remains unclear. The aims of this study were to compare RR-interval and heart rate variability indices in individuals of different habitual physical activity levels, and examine the relationship between habitual physical activity and heart rate variability. Ninety-two healthy volunteers (47 men, 45

  20. MRS: a noninvasive window into cardiac metabolism.

    PubMed

    van Ewijk, Petronella A; Schrauwen-Hinderling, Vera B; Bekkers, Sebastiaan C A M; Glatz, Jan F C; Wildberger, Joachim E; Kooi, M Eline

    2015-07-01

    A well-functioning heart requires a constant supply of a balanced mixture of nutrients to be used for the production of adequate amounts of adenosine triphosphate, which is the main energy source for most cellular functions. Defects in cardiac energy metabolism are linked to several myocardial disorders. MRS can be used to study in vivo changes in cardiac metabolism noninvasively. MR techniques allow repeated measurements, so that disease progression and the response to treatment or to a lifestyle intervention can be monitored. It has also been shown that MRS can predict clinical heart failure and death. This article focuses on in vivo MRS to assess cardiac metabolism in humans and experimental animals, as experimental animals are often used to investigate the mechanisms underlying the development of metabolic diseases. Various MR techniques, such as cardiac (31) P-MRS, (1) H-MRS, hyperpolarized (13) C-MRS and Dixon MRI, are described. A short overview of current and emerging applications is given. Cardiac MRS is a promising technique for the investigation of the relationship between cardiac metabolism and cardiac disease. However, further optimization of scan time and signal-to-noise ratio is required before broad clinical application. In this respect, the ongoing development of advanced shimming algorithms, radiofrequency pulses, pulse sequences, (multichannel) detection coils, the use of hyperpolarized nuclei and scanning at higher magnetic field strengths offer future perspective for clinical applications of MRS. Copyright © 2015 John Wiley & Sons, Ltd. PMID:26010681

  1. Controlled Cardiac Computed Tomography

    PubMed Central

    Wang, Chenglin; Liu, Ying; Wang, Ge

    2006-01-01

    Cardiac computed tomography (CT) has been a hot topic for years because of the clinical importance of cardiac diseases and the rapid evolution of CT systems. In this paper, we propose a novel strategy for controlled cardiac CT that may effectively reduce image artifacts due to cardiac and respiratory motions. Our approach is radically different from existing ones and is based on controlling the X-ray source rotation velocity and powering status in reference to the cardiac motion. We theoretically show that by such a control-based intervention the data acquisition process can be optimized for cardiac CT in the cases of periodic and quasiperiodic cardiac motions. Specifically, we formulate the corresponding coordination/control schemes for either exact or approximate matches between the ideal and actual source positions, and report representative simulation results that support our analytic findings. PMID:23165017

  2. [Monitoring and rehabilitation of heterotopic cardiac transplantation patients during the period of convalescence].

    PubMed

    Sieurat, P; Roquebrune, J P; Grinneiser, D; Bourlon, F; Elbèze, J P; Jourdan, J; Dor, V

    1986-02-01

    Heterotopic cardiac transplantation is a procedure performed in patients with severe pulmonary hypertension. Surgery is usually preceded by a long period of inactivity. This paper reports the results of a programme of cardiac readaptation, the complications observed, the improvement obtained and the problem replated to the absence of graft innervation. Eight patients who underwent heterotopic cardiac transplantation underwent the readaptation programme. This began with an exercise ECG on which the physical training programme was based. Sessions of respiratory and muscular physiotherapy were also arranged during the same period; a second exercise ECG was performed at the end of the programme to assess progress. Clinical, biological, electrocardiographic and echocardiographic parameters were carefully monitored. The results of the final exercise ECG showed the average maximal work capacity to be 90 watts for 3 minutes. The average increase in heart rate on effort was 25.92%. This was significantly higher than the resting heart rate (p less than 0.01). Two complications were observed during the programme: ventricular fibrillation of the cardiac graft and graft rejection on the 35th postoperative day, diagnosed by echocardiography. Progression of exercise capacity was observed in all patients. The two patients who made the least progress were those who underwent the fewest sessions of physical readaptation. This improvement was mainly related to peripheral muscular fitness. The training programme was well tolerated by all patients; the principal factor limiting an increase in cardiac output on effort was the absence of graft innervation. The heart rate can only be increased by two mechanisms: an increased venous return and raised concentrations of circulating catecholamines.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3085621

  3. Safety of Preoperative Autologous Blood Donations in Cardiac Surgery

    Microsoft Academic Search

    B. H. Walpoth; F. Aregger; C. Imboden; E. Auckenthaler; U. Nydegger; T. Carrel

    2002-01-01

    Summary Background: The aim of this study was to assess the safety of preoperative autologous blood donation (PABD) during cardiac surgery. Methods: 64 patients undergoing first-time elective cardiac surgery were prospectively followed up during PABD before cardiac surgery. Three blood donations in weekly intervals were performed, and all patients received oral (350 mg/day FE+) or i.v. iron (150 mg /week)

  4. Increase in cardiac myosin heavy-chain (MyHC) alpha protein isoform in hibernating ground squirrels, with echocardiographic visualization of ventricular wall hypertrophy and prolonged contraction.

    PubMed

    Nelson, O Lynne; Rourke, Bryan C

    2013-12-15

    Deep hibernators such as golden-mantled ground squirrels (Callospermophilus lateralis) have multiple challenges to cardiac function during low temperature torpor and subsequent arousals. As heart rates fall from over 300 beats min(-1) to less than 10, chamber dilation and reduced cardiac output could lead to congestive myopathy. We performed echocardiography on a cohort of individuals prior to and after several months of hibernation. The left ventricular chamber exhibited eccentric and concentric hypertrophy during hibernation and thus calculated ventricular mass was ~30% greater. Ventricular ejection fraction was mildly reduced during hibernation but stroke volumes were greater due to the eccentric hypertrophy and dramatically increased diastolic filling volumes. Globally, the systolic phase in hibernation was ~9.5 times longer, and the diastolic phase was 28× longer. Left atrial ejection generally was not observed during hibernation. Atrial ejection returned weakly during early arousal. Strain echocardiography assessed the velocity and total movement distance of contraction and relaxation for regional ventricular segments in active and early arousal states. Myocardial systolic strain during early arousal was significantly greater than the active state, indicating greater total contractile movement. This mirrored the increased ventricular ejection fraction noted with early arousal. However, strain rates were slower during early arousal than during the active period, particularly systolic strain, which was 33% of active, compared with the rate of diastolic strain, which was 67% of active. As heart rate rose during the arousal period, myocardial velocities and strain rates also increased; this was matched closely by cardiac output. Curiously, though heart rates were only 26% of active heart rates during early arousal, the cardiac output was nearly 40% of the active state, suggesting an efficient pumping system. We further analyzed proportions of cardiac myosin heavy-chain (MyHC) isoforms in a separate cohort of squirrels over 5 months, including time points before hibernation, during hibernation and just prior to emergence. Hibernating individuals were maintained in both a 4°C cold room and a 20°C warm room. Measured by SDS-PAGE, relative percentages of cardiac MyHC alpha were increased during hibernation, at both hibernacula temperatures. A potential increase in contractile speed, and power, from more abundant MyHC alpha may aid force generation at low temperature and at low heart rates. Unlike many models of cardiomyopathies where the alpha isoform is replaced by the beta isoform in order to reduce oxygen consumption, ground squirrels demonstrate a potential cardioprotective mechanism to maintain cardiac output during torpor. PMID:24072796

  5. Increase in cardiac myosin heavy-chain (MyHC) alpha protein isoform in hibernating ground squirrels, with echocardiographic visualization of ventricular wall hypertrophy and prolonged contraction

    PubMed Central

    Nelson, O. Lynne; Rourke, Bryan C.

    2013-01-01

    SUMMARY Deep hibernators such as golden-mantled ground squirrels (Callospermophilus lateralis) have multiple challenges to cardiac function during low temperature torpor and subsequent arousals. As heart rates fall from over 300 beats min?1 to less than 10, chamber dilation and reduced cardiac output could lead to congestive myopathy. We performed echocardiography on a cohort of individuals prior to and after several months of hibernation. The left ventricular chamber exhibited eccentric and concentric hypertrophy during hibernation and thus calculated ventricular mass was ~30% greater. Ventricular ejection fraction was mildly reduced during hibernation but stroke volumes were greater due to the eccentric hypertrophy and dramatically increased diastolic filling volumes. Globally, the systolic phase in hibernation was ~9.5 times longer, and the diastolic phase was 28× longer. Left atrial ejection generally was not observed during hibernation. Atrial ejection returned weakly during early arousal. Strain echocardiography assessed the velocity and total movement distance of contraction and relaxation for regional ventricular segments in active and early arousal states. Myocardial systolic strain during early arousal was significantly greater than the active state, indicating greater total contractile movement. This mirrored the increased ventricular ejection fraction noted with early arousal. However, strain rates were slower during early arousal than during the active period, particularly systolic strain, which was 33% of active, compared with the rate of diastolic strain, which was 67% of active. As heart rate rose during the arousal period, myocardial velocities and strain rates also increased; this was matched closely by cardiac output. Curiously, though heart rates were only 26% of active heart rates during early arousal, the cardiac output was nearly 40% of the active state, suggesting an efficient pumping system. We further analyzed proportions of cardiac myosin heavy-chain (MyHC) isoforms in a separate cohort of squirrels over 5 months, including time points before hibernation, during hibernation and just prior to emergence. Hibernating individuals were maintained in both a 4°C cold room and a 20°C warm room. Measured by SDS-PAGE, relative percentages of cardiac MyHC alpha were increased during hibernation, at both hibernacula temperatures. A potential increase in contractile speed, and power, from more abundant MyHC alpha may aid force generation at low temperature and at low heart rates. Unlike many models of cardiomyopathies where the alpha isoform is replaced by the beta isoform in order to reduce oxygen consumption, ground squirrels demonstrate a potential cardioprotective mechanism to maintain cardiac output during torpor. PMID:24072796

  6. An electricity-focused economic input-output model: Life-cycle assessment and policy implications of future electricity generation scenarios

    NASA Astrophysics Data System (ADS)

    Marriott, Joe

    The electricity industry is extremely important to both our economy and our environment. We would like to be able to examine the economic, environmental and policy implications of both future electricity scenarios which include advanced generation technologies such as gasified coal, and of the products and processes which will use them, along with the interaction of this industry with the rest of the economy. This work builds upon an existing economic input-output framework, by adding detail about the electricity industry, specifically by differentiating among the various functions of the sector, and the different means of generating power. The mix of electricity consumed at any stage in the life-cycle of a product, process or industrial sector has a significant effect on the associated inventory of emissions. Fossil fuel or nuclear generators, large-scale hydroelectric, and renewable options such as geothermal, wind and solar each have a unique set of issues---both in the production of electricity at the plant and throughout the supply chain. Decision makers need better information regarding the environmental and economic impact of the electricity industry, including full supply chain details---the interaction of the electricity industry with the other 500 sectors of the economy. A systematic method for creating updated state level and sector generation mixes is developed. The results show that most sector mixes are very close to the U.S. average due to geographic dispersion of industries, but that some sectors are different, and they tend to be important raw material extraction or primary manufacturing industries. We then build a flexible framework for creating new sectors, supply chains and emission factors for the generation, transmission and distribution portions of the electricity industry. We look at scenarios of the present and future, for electricity and for particular products, and develop results which show environmental impacts split up by generation type, and with full supply chain detail. For analyses of the current electricity system and products, economic and environmental results match well with external verification sources, but for analyses of the future, there is significant uncertainty.

  7. Diodes stabilize LED output

    NASA Technical Reports Server (NTRS)

    Deters, R. A.

    1977-01-01

    Small-signal diodes are placed in series with light-emitting diodes (LED's) to stabilize LED output against temperature fluctuations. Simple inexpensive method compensates for thermal fluctuations over a broad temperature range. Requiring few components, technique is particularly useful where circuit-board space is limited.

  8. Input/Output Trends.

    ERIC Educational Resources Information Center

    Mitchell, J.

    This paper discusses batch processing; and on-line, time-sharing operations, and their associate input/output equipment. Special emphasis is placed on electronic display equipment. It concludes that future equipment trends will allow the user more and easier access to the machine he uses. (Author)

  9. Convergence in International Output

    Microsoft Academic Search

    Andrew B. Bernard; Steven N. Durlauf

    1995-01-01

    This paper proposes and tests new definitions of convergence and common trends for per capita output. We define convergence for a group of countries to mean that each country has identical long-run trends, either stochastic, while common trends allow for proportionality of the stochastic elements. These definitions lead naturally to the use of cointegration techniques in testing. Using century-long time

  10. AN INTEGRATEDMICROELECTROMECHANICALRESONANT OUTPUT GYROSCOPE -

    E-print Network

    Tang, William C

    AN INTEGRATEDMICROELECTROMECHANICALRESONANT OUTPUT GYROSCOPE - Ashwin A. Seshia*,Roger T. Howe vibratory rate gyroscope based on resonant sensing of the Coriolis force. The new design has several advantages over rate gyroscopes that utilize open-loop displacement sensing for rotation rate measurement

  11. programming input/output

    E-print Network

    Liu, Yanhong Annie

    would ML fit in? COBOL and ML could safely be put down far apart. The in­ put/output facilities in COBOL to the verbose COBOL and ML is much better suited for structuring data and algorithms than COBOL is. ML is closer

  12. Two-scale evaluation of remediation technologies for a contaminated site by applying economic input-output life cycle assessment: risk-cost, risk-energy consumption and risk-CO2 emission.

    PubMed

    Inoue, Yasushi; Katayama, Arata

    2011-09-15

    A two-scale evaluation concept of remediation technologies for a contaminated site was expanded by introducing life cycle costing (LCC) and economic input-output life cycle assessment (EIO-LCA). The expanded evaluation index, the rescue number for soil (RN(SOIL)) with LCC and EIO-LCA, comprises two scales, such as risk-cost, risk-energy consumption or risk-CO(2) emission of a remediation. The effectiveness of RN(SOIL) with LCC and EIO-LCA was examined in a typical contamination and remediation scenario in which dieldrin contaminated an agricultural field. Remediation was simulated using four technologies: disposal, high temperature thermal desorption, biopile and landfarming. Energy consumption and CO(2) emission were determined from a life cycle inventory analysis using monetary-based intensity based on an input-output table. The values of RN(SOIL) based on risk-cost, risk-energy consumption and risk-CO(2) emission were calculated, and then rankings of the candidates were compiled according to RN(SOIL) values. A comparison between three rankings showed the different ranking orders. The existence of differences in ranking order indicates that the scales would not have reciprocal compatibility for two-scale evaluation and that each scale should be used independently. The RN(SOIL) with LCA will be helpful in selecting a technology, provided an appropriate scale is determined. PMID:21741766

  13. Reversing Heart Failure: Diastolic Recoil in a Proposed Cardiac Support Device

    E-print Network

    Snowden, Timothy D

    2012-07-11

    Congestive heart failure (CHF) holds millions in the grip of an endless cycle of decreased cardiac output and degenerative remodeling, often with little hope of recovery. Diastolic dysfunction, or failure of the heart to properly fill, is a...

  14. Reversing Heart Failure: Diastolic Recoil in a Proposed Cardiac Support Device 

    E-print Network

    Snowden, Timothy D

    2012-07-11

    Congestive heart failure (CHF) holds millions in the grip of an endless cycle of decreased cardiac output and degenerative remodeling, often with little hope of recovery. Diastolic dysfunction, or failure of the heart to properly fill, is a...

  15. Cardiac output and cardiac contractility by impedance cardiography during exercise of runners

    NASA Technical Reports Server (NTRS)

    Kubicek, W. G.; Tracy, R. A.

    1994-01-01

    Most of the solid state electronic engineering of the system now generally known as the Minnesota Impedance Cardiograph was performed with the support of a five-year contract, NAS9-4500, with the NASA Lyndon B. Johnson Space Center, Houston, Texas. This contract ran from 1965 to 1970. In addition to the engineering design and development of the hardware, the contract called for testing on both animals and human subjects. This project also provided funds to construct twenty impedance cardiographs and place them in selected research and clinical facilities for further evaluation. This, then, led to the First Symposium on Impedance Cardiography, held at the NASA Lyndon B. Johnson Space Center, Houston, Texas, 2-4 June 1969. Twenty-four excellent papers were presented.

  16. Cardiac innervation and sudden cardiac death.

    PubMed

    Fukuda, Keiichi; Kanazawa, Hideaki; Aizawa, Yoshiyasu; Ardell, Jeffrey L; Shivkumar, Kalyanam

    2015-06-01

    Afferent and efferent cardiac neurotransmission via the cardiac nerves intricately modulates nearly all physiological functions of the heart (chronotropy, dromotropy, lusitropy, and inotropy). Afferent information from the heart is transmitted to higher levels of the nervous system for processing (intrinsic cardiac nervous system, extracardiac-intrathoracic ganglia, spinal cord, brain stem, and higher centers), which ultimately results in efferent cardiomotor neural impulses (via the sympathetic and parasympathetic nerves). This system forms interacting feedback loops that provide physiological stability for maintaining normal rhythm and life-sustaining circulation. This system also ensures that there is fine-tuned regulation of sympathetic-parasympathetic balance in the heart under normal and stressed states in the short (beat to beat), intermediate (minutes to hours), and long term (days to years). This important neurovisceral/autonomic nervous system also plays a major role in the pathophysiology and progression of heart disease, including heart failure and arrhythmias leading to sudden cardiac death. Transdifferentiation of neurons in heart failure, functional denervation, cardiac and extracardiac neural remodeling has also been identified and characterized during the progression of disease. Recent advances in understanding the cellular and molecular processes governing innervation and the functional control of the myocardium in health and disease provide a rational mechanistic basis for the development of neuraxial therapies for preventing sudden cardiac death and other arrhythmias. Advances in cellular, molecular, and bioengineering realms have underscored the emergence of this area as an important avenue of scientific inquiry and therapeutic intervention. PMID:26044253

  17. Thrombospondin-1 and CD47 regulate blood pressure and cardiac responses to vasoactive stress

    E-print Network

    Frazier, William A.

    Thrombospondin-1 and CD47 regulate blood pressure and cardiac responses to vasoactive stress Jeff S pressure Cardiac output Nitric oxide (NO) locally regulates vascular resistance and blood pressure-associated increases in heart rate, central diastolic and mean arterial blood pressure and a constant decrease in pulse

  18. Multi-Variate Visualization of Cardiac Virtual Tissue J W Handley

    E-print Network

    Brodlie, Ken

    Multi-Variate Visualization of Cardiac Virtual Tissue J W Handley K W Brodlie School of Computing United Kingdom r.clayton@dcs.shef.ac.uk Abstract In standard analysis of cardiac models, typically one visualizing the output of the model. In this paper, we present a novel approach to visualizing the entire

  19. Cardiac rehabilitation in Europe: results from the European Cardiac Rehabilitation Inventory Survey

    Microsoft Academic Search

    Birna Bjarnason-Wehrens; Hannah McGee; Ann-Dorthe Zwisler; Massimo F. Piepoli; Werner Benzer; Jean-Paul Schmid; Paul Dendale; Nana-Goar V. Pogosova; Dumitru Zdrenghea; Josef Niebauer; Miguel Mendes

    2010-01-01

    Background Cardiac rehabilitation (CR) programmes support patients to achieve professionally recommended cardiovascular prevention targets and thus good clinical status and improved quality of life and prognosis. Information on CR service delivery in Europe is sketchy.Design Postal survey of national CR-related organizations in European countries.Methods The European Cardiac Rehabilitation Inventory Survey assessed topics including national guidelines, legislation and funding mechanisms, phases

  20. Cardiac Status after Childhood Growth Hormone Treatment of Turner Syndrome

    Microsoft Academic Search

    Jochem van den Berg; Ellen M. N. Bannink; Piotr A. Wielopolski; Wim C. J. Hop; Lennie van Osch-Gevers; Peter M. T. Pattynama; Willem A. Helbing

    2010-01-01

    Context: In Turner syndrome (TS), GH treatment is well established. Data on cardiac status after discontinuation of treatment are scarce. This study aimed to assess biventricular size and function in TS at least 6 months after discontinuation of GH treatment. Methods: TS patients and healthy women prospectively underwent cardiac magnetic resonance imaging. Ventricular two-dimensional tomographic cine data were acquired to

  1. Hyperplastic cardiac sarcoma recurrence.

    PubMed

    Shariff, Masood A; Abreu, Juan A; Durrani, Farida; Daniele, Eddie; Bowman, Kimberly C; Sadel, Scott; Asgarian, Kourosh T; McGinn, Joseph T; Nabagiez, John P

    2015-01-01

    Primary cardiac sarcomas are rare tumors with a median survival of 6-12 months. Data suggest that an aggressive multidisciplinary approach may improve patient outcome. We present the case of a male who underwent resection of cardiac sarcoma three times from the age of 32 to 34. This report discusses the malignant nature of cardiac sarcoma and the importance of postoperative multidisciplinary care. PMID:25861508

  2. Assessment of radiochromic gel dosimeter based on Turnbull Blue dye for relative output factor measurements of the Leksell Gamma Knife® PerfexionTM

    NASA Astrophysics Data System (ADS)

    Kozubikova, P.; Solc, J.; Novotny, J., Jr.; Pilarova, K.; Pipek, J.; Koncekova, J.

    2015-01-01

    The aim of the study was to perform assessment of radiochromic gel dosimeter based on Turnbull blue dye formed by irradiation (TB gel dosimeter) for measurement of ROFs for 4 mm and 8 mm collimators for the Leksell Gamma Knife PerfexionTM. All measurements have been carried out using home-made spherical Perspex glass phantom of diameter 160 mm. TB gel dosimeters were scanned using homemade optical CT scanner. The results are compared with vendor recommended Monte Carlo calculated ROFs values of 0.814 and 0.900 for 4 mm and 8 mm collimators, respectively. The comparisons between the gel measurements and the treatment planning system (TPS) calculation are presented in the form of 2D isodoses for the central slices and 1D profile. Measured ROF 0.746 and 0.874 for 4 mm and 8 mm collimators respectively are in a reasonable agreement with vendor recommended values and measured relative dose distribution in a central slice and measured profiles of all shots show excellent correspondence with TPS.

  3. A methodology for fast assessments to the electrical activity of barrel fields in vivo: from population inputs to single unit outputs

    PubMed Central

    Riera, Jorge J.; Goto, Takakuni; Kawashima, Ryuta

    2014-01-01

    Here we propose a methodology to analyze volumetric electrical activity of neuronal masses in the somatosensory barrel field of Wistar rats. The key elements of the proposed methodology are a three-dimensional microelectrode array, which was customized by our group to observe extracellular recordings from an extended area of the barrel field, and a novel method for the current source density analysis. By means of this methodology, we were able to localize single barrels from their event-related responses to single whisker deflection. It was also possible to assess the spatiotemporal dynamics of neuronal aggregates in several barrels at the same time with the resolution of single neurons. We used simulations to study the robustness of our methodology to unavoidable physiological noise and electrode configuration. We compared the accuracy to reconstruct neocortical current sources with that obtained with a previous method. This constitutes a type of electrophysiological microscopy with high spatial and temporal resolution, which could change the way we analyze the activity of cortical neurons in the future. PMID:24550785

  4. Expression of SGLT1 in Human Hearts and Impairment of Cardiac Glucose Uptake by Phlorizin during Ischemia-Reperfusion Injury in Mice

    PubMed Central

    Kashiwagi, Yusuke; Nagoshi, Tomohisa; Yoshino, Takuya; Tanaka, Toshikazu D.; Ito, Keiichi; Harada, Tohru; Takahashi, Hiroyuki; Ikegami, Masahiro; Anzawa, Ryuko; Yoshimura, Michihiro

    2015-01-01

    Objective Sodium-glucose cotransporter 1 (SGLT1) is thought to be expressed in the heart as the dominant isoform of cardiac SGLT, although more information is required to delineate the subtypes of SGLTs in human hearts. Moreover, the functional role of SGLTs in the heart remains to be fully elucidated. We herein investigated whether SGLT1 is expressed in human hearts and whether SGLTs significantly contribute to cardiac energy metabolism during ischemia-reperfusion injury (IRI) via enhanced glucose utilization in mice. Methods and Results We determined that SGLT1 was highly expressed in both human autopsied hearts and murine perfused hearts, as assessed by immunostaining and immunoblotting with membrane fractionation. To test the functional significance of the substantial expression of SGLTs in the heart, we studied the effects of a non-selective SGLT inhibitor, phlorizin, on the baseline cardiac function and its response to ischemia-reperfusion using the murine Langendorff model. Although phlorizin perfusion did not affect baseline cardiac function, its administration during IRI significantly impaired the recovery in left ventricular contractions and rate pressure product, associated with an increased infarct size, as demonstrated by triphenyltetrazolium chloride staining and creatine phosphokinase activity released into the perfusate. The onset of ischemic contracture, which indicates the initiation of ATP depletion in myocardium, was earlier with phlorizin. Consistent with this finding, there was a significant decrease in the tissue ATP content associated with reductions in glucose uptake, as well as lactate output (indicating glycolytic flux), during ischemia-reperfusion in the phlorizin-perfused hearts. Conclusions Cardiac SGLTs, possibly SGLT1 in particular, appear to provide an important protective mechanism against IRI by replenishing ATP stores in ischemic cardiac tissues via enhancing availability of glucose. The present findings provide new insight into the significant role of SGLTs in optimizing cardiac energy metabolism, at least during the acute phase of IRI. PMID:26121582

  5. Cardiac side population cells exhibit endothelial differentiation potential.

    PubMed

    Yoon, Jihyun; Choi, Seung Cheol; Park, Chi Yeon; Shim, Wan Joo; Lim, Do-Sun

    2007-10-31

    Recent studies have shown that side population (SP) cells, isolated from adult myocardium, represent a distinct cardiac progenitor cell population that exhibits functional cardiomyogenic differentiation. However, information on the intrinsic characteristics and endothelial potential, of cardiac SP cells, is limited. The present study was designed to investigate whether cardiac SP cells exhibit endothelial differentiation potential. The cardiac SP cells more highly expressed the early cardiac transcription factors as well as endothelial cell markers compared to the bone marrow-SP cells. After treatment with VEGF, for 28 days, cardiac SP cells were able to differentiate into endothelial cells expressing von Willebrand factor as determined by immunocytochemistry. Furthermore, expression of endothelial cell markers increased several-fold in VEGF-treated cardiac SP cells compared to the control group when assessed by real-time PCR. We also confirmed that cardiac SP cells provided a significantly augmented ratio of ischemic/normal blood flow, in the cardiac SP cell-transplanted group compared with saline-treated controls on postoperative days 7, 14, 21 and 28, in a murine model. These results show that cardiac SP cells may contribute to regeneration of injured heart tissues partly by transdifferentiation into angiogenic lineages. PMID:18059141

  6. Three-dimensional cardiac computational modelling: methods, features and applications.

    PubMed

    Lopez-Perez, Alejandro; Sebastian, Rafael; Ferrero, Jose M

    2015-01-01

    The combination of computational models and biophysical simulations can help to interpret an array of experimental data and contribute to the understanding, diagnosis and treatment of complex diseases such as cardiac arrhythmias. For this reason, three-dimensional (3D) cardiac computational modelling is currently a rising field of research. The advance of medical imaging technology over the last decades has allowed the evolution from generic to patient-specific 3D cardiac models that faithfully represent the anatomy and different cardiac features of a given alive subject. Here we analyse sixty representative 3D cardiac computational models developed and published during the last fifty years, describing their information sources, features, development methods and online availability. This paper also reviews the necessary components to build a 3D computational model of the heart aimed at biophysical simulation, paying especial attention to cardiac electrophysiology (EP), and the existing approaches to incorporate those components. We assess the challenges associated to the different steps of the building process, from the processing of raw clinical or biological data to the final application, including image segmentation, inclusion of substructures and meshing among others. We briefly outline the personalisation approaches that are currently available in 3D cardiac computational modelling. Finally, we present examples of several specific applications, mainly related to cardiac EP simulation and model-based image analysis, showing the potential usefulness of 3D cardiac computational modelling into clinical environments as a tool to aid in the prevention, diagnosis and treatment of cardiac diseases. PMID:25928297

  7. Perioperative care of the patient with cardiovascular disease undergoing non-cardiac surgery

    Microsoft Academic Search

    Florian Falter; Giampaolo Martinelli

    2005-01-01

    The risk of perioperative cardiac events in cardiac patients undergoing non-cardiac surgery may be weighed against the benefits of proposed surgery using clinical risk factor analysis and different methods of assessing myocardial functional reserve. Stress testing modalities accurately delineate reversible myocardial ischaemia, but their positive predictive value is disputed, and it is unclear if their implementation improves outcome when compared

  8. Role of Cardiac MR Imaging in Cardiomyopathies.

    PubMed

    Kramer, Christopher M

    2015-06-01

    Cardiac MR imaging has made major inroads in the new millennium in the diagnosis and assessment of prognosis for patients with cardiomyopathies. Imaging of left and right ventricular structure and function and tissue characterization with late gadolinium enhancement (LGE) as well as T1 and T2 mapping enable accurate diagnosis of the underlying etiology. In the setting of coronary artery disease, either transmurality of LGE or contractile reserve in response to dobutamine can assess the likelihood of recovery of function after revascularization. The presence of scar reduces the likelihood of a response to medical therapy and to cardiac resynchronization therapy in heart failure. The presence and extent of LGE relate to overall cardiovascular outcome in cardiomyopathies. A major role for cardiac MR imaging in cardiomyopathies is to identify myocardial scar for diagnostic and prognostic purposes. PMID:26033902

  9. I-123- m IBG myocardial imaging for assessment of risk for a major cardiac event in heart failure patients: insights from a retrospective European multicenter study

    Microsoft Academic Search

    Denis Agostini; Hein J. Verberne; Wolfgang Burchert; Juhani Knuuti; Pavol Povinec; Gianmario Sambuceti; Mustafa Unlu; Montserrat Estorch; Gopa Banerjee; Arnold F. Jacobson

    2008-01-01

    Purpose  Single-center experiences have shown that myocardial meta-iodobenzylguanidine (mIBG) uptake has prognostic value in heart failure (HF) patients. To verify these observations using a rigorous clinical trial\\u000a methodology, a retrospective review and prospective quantitative reanalysis was performed on a series of cardiac 123I-mIBG scans acquired during a 10-year period at six centers in Europe.\\u000a \\u000a \\u000a \\u000a Methods  \\u000a 123I-mIBG scans obtained on 290 HF

  10. Assessment of acute myocardial infarction: current status and recommendations from the North American society for cardiovascular imaging and the European society of cardiac radiology

    PubMed Central

    Oudkerk, Matthijs; Bluemke, David; Bremerich, Jens; Esteves, Fabio P.; Garcia, Ernest V.; Gutberlet, Matthias; Hundley, W. Gregory; Jerosch-Herold, Michael; Kuijpers, Dirkjan; Kwong, Raymond K.; Nagel, Eike; Lerakis, Stamatios; Oshinski, John; Paul, Jean-François; Underwood, Richard; Wintersperger, Bernd J.; Rees, Michael R.

    2010-01-01

    There are a number of imaging tests that are used in the setting of acute myocardial infarction and acute coronary syndrome. Each has their strengths and limitations. Experts from the European Society of Cardiac Radiology and the North American Society for Cardiovascular Imaging together with other prominent imagers reviewed the literature. It is clear that there is a definite role for imaging in these patients. While comparative accuracy, convenience and cost have largely guided test decisions in the past, the introduction of newer tests is being held to a higher standard which compares patient outcomes. Multicenter randomized comparative effectiveness trials with outcome measures are required. PMID:20972835

  11. Brain injury after cardiac surgery.

    PubMed

    Scolletta, S; Taccone, F S; Donadello, K

    2015-06-01

    In patients undergoing cardiac surgery, postoperative brain injury significantly contributes to increase morbidity and mortality and has negative consequences on quality of life and costs. Moreover, over the past years, compelling medical and technological improvements have allowed an even older patients' population, with several comorbidities, to be treated with cardiac surgery; however, the risk of brain injury after such interventions is also increased in these patients. With the aim of improving post-operative neurological outcome, a variety of neuromonitoring methods and devices have been introduced in clinical practice. These techniques allow the assessment of a number of parameters, such as cerebral blood flow, brain embolic events, cerebral cortical activity, depth of anesthesia and brain oxygenation. Some of them have been used to optimize the hemodynamic management of such patients and to select specific therapeutic interventions. Also, various pharmacological and non-pharmacological approaches have been proposed to minimize the incidence of brain injury in this setting. In this review we describe the risk factors and mechanisms of cerebral injury after cardiac surgery and focus on monitoring techniques and clinical strategies that could help clinicians to minimize the incidence of brain injury. PMID:25220549

  12. THE CARDIOVASCULAR RESPONSES OF THE RED-EARED SLIDER (TRACHEMYS SCRIPTA) ACCLIMATED TO EITHER 22 OR 5 °C I. EFFECTS OF ANOXIC EXPOSURE ON IN VIVO CARDIAC PERFORMANCE

    Microsoft Academic Search

    J. M. T. HICKS; A. P. FARRELL

    The extreme anoxia-tolerance of freshwater turtles under cold conditions is well documented, but little is known about their cardiac performance in such situations. Using chronic catheterization techniques, we measured systemic cardiac power output (POsys), systemic cardiac output (Q. sys), heart rate (fH), systemic stroke volume (Vs,sys), systemic resistance (Rsys) and mean arterial pressure (Psys) in red-eared sliders (Trachemys scripta). The

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

    Microsoft Academic Search

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

    2007-01-01

    iodothyronamine T1AM is a novel en- dogenous 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. ,2 75, 513, and 652% decrease in cardiac output at 19, 25, and 38 M concentration, respec-

  14. Cardiac risk telemonitoring

    Microsoft Academic Search

    H. Hutten; M. Hribernigg; G. Rauchegger

    2001-01-01

    Utilization of advanced information, telecommunication and implant technology for cardiac risk stratification and management is one of the greatest challenges for modern health care provision. Sudden cardiac death is the major contributor to overall cardiovascular mortality with approximately 60% of all coronary heart disease fatalities occurring annually. Although some high-risk patient groups have been identified with reasonable sensitivity and specificity

  15. Garfinkel Cardiac Data

    NSDL National Science Digital Library

    Alan Garfinkel (University of California Los Angeles; Physiological Sci/Med-Cardio)

    2009-01-10

    Cardiac data on multiple variables for a selected population of 220 men and 338 women participating in a drug treatment study of dobutamine for heart attack prevention. Garfinkel, Alan, et. al. "Prognostic Value of Dobutamine Stress Echocardiography in Predicting Cardiac Events in Patients With Known or Suspected Coronary Artery Disease." Journal of the American College of Cardiology 33.3 (1999) 708-16.

  16. Motor Vehicle Output and GDP, 1968–2007

    Microsoft Academic Search

    Danilo J. Santini; David A. Poyer

    2008-01-01

    In this paper, we assess the performance of the BEA series “value of motor vehicle output” as an indicator of the business\\u000a cycle over the period 1968–2007. We statistically assess the causal relationship between real motor vehicle output (RMVO)\\u000a and real gross domestic product (RGDP). This is accomplished by standard estimation and statistical methods used to assess\\u000a vector autoregressive models.

  17. Usefulness of the severity and extent of reversible perfusion defects during thallium-dipyridamole imaging for cardiac risk assessment before noncardiac surgery

    SciTech Connect

    Lette, J.; Waters, D.; Lapointe, J.; Gagnon, A.; Picard, M.; Cerino, M.; Kerouac, M. (Maisonneuve-Rosemont Hospital, Montreal, Quebec (Canada))

    1989-08-01

    Thallium-dipyridamole imaging is a very sensitive test for predicting cardiac events after noncardiac surgery, but it lacks specificity. To improve specificity, a semiquantitative scoring system was developed that combined dipyridamole-induced reversible left ventricular dilatation with scintigraphic indexes for severity and extent of reversible perfusion defects. Using this scoring system, patients were classified into low, intermediate and high risk subgroups. Thallium-dipyridamole imaging was performed in 66 patients before major general and vascular surgery. Thirty-nine patients classified as low risk (30 with normal scans and 9 with fixed defects) underwent surgery uneventfully. Surgery was cancelled in 6 patients with extensive thallium redistribution and coronary angiography was performed because of severe coronary artery disease in 5 and idiopathic dilated cardiomyopathy in 1. In the remaining 21 patients with thallium redistribution, a positive statistical correlation (p = 0.001) between scintigraphic indexes of severity and extent, and cardiac events was noted. Using cutoff values for the scintigraphic indexes, patients with reversible defects could be classified into intermediate and high risk subgroups. Only 1 of 11 patients at intermediate risk developed a complication, whereas 8 of 10 patients at high risk had a postoperative event (7 deaths and 1 myocardial infarction). Thus, using scintigraphic indexes for severity and extent, patients with reversible defects can be stratified into an intermediate risk subgroup that can safely undergo surgery and a high risk subgroup that requires coronary angiography.

  18. Quantitative assessment of brain tissue oxygenation in porcine models of cardiac arrest and cardiopulmonary resuscitation using hyperspectral near-infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Lotfabadi, Shahin S.; Toronov, Vladislav; Ramadeen, Andrew; Hu, Xudong; Kim, Siwook; Dorian, Paul; Hare, Gregory M. T.

    2014-03-01

    Near-infrared spectroscopy (NIRS) is a non-invasive tool to measure real-time tissue oxygenation in the brain. In an invasive animal experiment we were able to directly compare non-invasive NIRS measurements on the skull with invasive measurements directly on the brain dura matter. We used a broad-band, continuous-wave hyper-spectral approach to measure tissue oxygenation in the brain of pigs under the conditions of cardiac arrest, cardiopulmonary resuscitation (CPR), and defibrillation. An additional purpose of this research was to find a correlation between mortality due to cardiac arrest and inadequacy of the tissue perfusion during attempts at resuscitation. Using this technique we measured the changes in concentrations of oxy-hemoglobin [HbO2] and deoxy-hemoglobin [HHb] to quantify the tissue oxygenation in the brain. We also extracted cytochrome c oxidase changes ?[Cyt-Ox] under the same conditions to determine increase or decrease in cerebral oxygen delivery. In this paper we proved that applying CPR, [HbO2] concentration and tissue oxygenation in the brain increase while [HHb] concentration decreases which was not possible using other measurement techniques. We also discovered a similar trend in changes of both [Cyt-Ox] concentration and tissue oxygen saturation (StO2). Both invasive and non-invasive measurements showed similar results.

  19. Noninvasive cardiac imaging in pulmonary hypertension.

    PubMed

    Sallach, Susan M; Peshock, Ron M; Reimold, Sharon

    2007-01-01

    Pulmonary artery hypertension is a rare disease with significant morbidity and mortality. Initial and serial noninvasive assessment of these patients can be accomplished with transthoracic echocardiography and/or cardiac magnetic resonance imaging. These complementary techniques provide the structural and functional information required to care for patients with pulmonary artery hypertension and are discussed in this review. PMID:17303996

  20. Cardiac Imaging System

    NASA Technical Reports Server (NTRS)

    1990-01-01

    Although not available to all patients with narrowed arteries, balloon angioplasty has expanded dramatically since its introduction with an estimated further growth to 562,000 procedures in the U.S. alone by 1992. Growth has fueled demand for higher quality imaging systems that allow the cardiologist to be more accurate and increase the chances of a successful procedure. A major advance is the Digital Cardiac Imaging (DCI) System designed by Philips Medical Systems International, Best, The Netherlands and marketed in the U.S. by Philips Medical Systems North America Company. The key benefit is significantly improved real-time imaging and the ability to employ image enhancement techniques to bring out added details. Using a cordless control unit, the cardiologist can manipulate images to make immediate assessment, compare live x-ray and roadmap images by placing them side-by-side on monitor screens, or compare pre-procedure and post procedure conditions. The Philips DCI improves the cardiologist's precision by expanding the information available to him.

  1. Neurons within the same network independently achieve conserved output by differentially balancing variable conductance magnitudes.

    PubMed

    Ransdell, Joseph L; Nair, Satish S; Schulz, David J

    2013-06-12

    Biological and theoretical evidence suggest that individual neurons may achieve similar outputs by differentially balancing variable underlying ionic conductances. Despite the substantial amount of data consistent with this idea, a direct biological demonstration that cells with conserved output, particularly within the same network, achieve these outputs via different solutions has been difficult to achieve. Here we demonstrate definitively that neurons from native neural networks with highly similar output achieve this conserved output by differentially tuning underlying conductance magnitudes. Multiple motor neurons of the crab (Cancer borealis) cardiac ganglion have highly conserved output within a preparation, despite showing a 2-4-fold range of conductance magnitudes. By blocking subsets of these currents, we demonstrate that the remaining conductances become unbalanced, causing disparate output as a result. Therefore, as strategies to understand neuronal excitability become increasingly sophisticated, it is important that such variability in excitability of neurons, even among those within the same individual, is taken into account. PMID:23761890

  2. New concepts in cardiac imaging 1985

    SciTech Connect

    Pohost, G.M.; Higgins, C.B.; Morganroth, J.; Ritchie, J.L.; Schelbert, H.R.

    1985-01-01

    This book presents 5 specialists work on reviewing and editing the area of applications for cardiac imaging: Contents: Ultrasound Methods; 1. Echocardiography in Valvular Heart Disease, 2. Echocardiography in Ischemic Heart Disease, 3. Current Status of Doppler Ultrasound for Assessing Regurgitant Valvular Lesions, Radionuclide Methods; 4. Cardiovascular Nuclear Medicine, 5. Single Photon Emission Computed Tomography (SPECT): Validation and Application for Myocardial Perfusion Imaging, 6. Assessment of Regional Myocardial Perfusion with Positron Emission Tomography, 7. Assessment of Regional Myocardial Substrate Metabolism with Positron Emission Tomography, X-Ray Imaging Techniques; 8. The Evaluation of Left Ventricular Function in Ischemic Heart Disease by Digital Subtraction Angigraphy, 9. Digital Angiography in the Assessment of Coronary Artery Disease, 10. Cardiac Computed Tomography: Its Potential Use in Evaluation of Ischemic Heart Disease, Magnetic Methods; 11. NMR Evaluation of the Cardiovascular System, 12. Magnetic Resonance Imaging of the Heart.

  3. Modeling inherited cardiac disorders.

    PubMed

    Sallam, Karim; Kodo, Kazuki; Wu, Joseph C

    2014-01-01

    Advances in the understanding and treatment of cardiac disorders have been thwarted by the inability to study beating human cardiac cells in vitro. Induced pluripotent stem cells (iPSCs) bypass this hurdle by enabling the creation of patient-specific iPSC-derived cardiomyocytes (iPSC-CMs). These cells provide a unique platform to study cardiac diseases in vitro, especially hereditary cardiac conditions. To date, iPSC-CMs have been used to successfully model arrhythmic disorders, showing excellent recapitulation of cardiac channel function and electrophysiologic features of long QT syndrome types 1, 2, 3, and 8, and catecholaminergic polymorphic ventricular tachycardia (CPVT). Similarly, iPSC-CM models of dilated cardiomyopathy (DCM) and hypertrophic cardiomyopathy (HCM) have shown robust correlation of predicted morphologic, contractile, and electrical phenotypes. In addition, iPSC-CMs have shown some features of the respective phenotypes for arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C), LEOPARD syndrome, Pompe's disease, and Friedriech's ataxia. In this review, we examine the progress of utilizing iPSC-CMs as a model for cardiac conditions and analyze the potential for the platform in furthering the biology and treatment of cardiac disorders.?? PMID:24632794

  4. [Cardiac manifestations of mitochondrial diseases].

    PubMed

    Ritzenthaler, Thomas; Luis, David; Hullin, Thomas; Fayssoil, Abdallah

    2015-05-01

    Mitochondrial diseases are multi-system disorders in relation with mitochondrial DNA and/or nuclear DNA abnormalities. Clinical pictures are heterogeneous, involving endocrine, cardiac, neurologic or sensory systems. Cardiac involvements are morphological and electrical disturbances. Prognosis is worsened in case of cardiac impairment. Treatments are related to the type of cardiac dysfunction including medication or pacemaker implantation. PMID:25890847

  5. Cardiac function of the naked mole-rat: ecophysiological responses to working underground.

    PubMed

    Grimes, Kelly M; Voorhees, Andrew; Chiao, Ying Ann; Han, Hai-Chao; Lindsey, Merry L; Buffenstein, Rochelle

    2014-03-01

    The naked mole-rat (NMR) is a strictly subterranean rodent with a low resting metabolic rate. Nevertheless, it can greatly increase its metabolic activity to meet the high energetic demands associated with digging through compacted soils in its xeric natural habitat where food is patchily distributed. We hypothesized that the NMR heart would naturally have low basal function and exhibit a large cardiac reserve, thereby mirroring the species' low basal metabolism and large metabolic scope. Echocardiography showed that young (2-4 yr old) healthy NMRs have low fractional shortening (28 ± 2%), ejection fraction (43 ± 2%), and cardiac output (6.5 ± 0.4 ml/min), indicating low basal cardiac function. Histology revealed large NMR cardiomyocyte cross-sectional area (216 ± 10 ?m(2)) and cardiac collagen deposition of 2.2 ± 0.4%. Neither of these histomorphometric traits was considered pathological, since biaxial tensile testing showed no increase in passive ventricular stiffness. NMR cardiomyocyte fibers showed a low degree of rotation, contributing to the observed low NMR cardiac contractility. Interestingly, when the exercise mimetic dobutamine (3 ?g/g ip) was administered, NMRs showed pronounced increases in fractional shortening, ejection fraction, cardiac output, and stroke volume, indicating an increased cardiac reserve. The relatively low basal cardiac function and enhanced cardiac reserve of NMRs are likely to be ecophysiological adaptations to life in an energetically taxing environment. PMID:24363308

  6. Molecular Basis of Cardiac Myxomas

    PubMed Central

    Singhal, Pooja; Luk, Adriana; Rao, Vivek; Butany, Jagdish

    2014-01-01

    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. PMID:24447924

  7. Inflation Targeting and Output Growth: Evidence from Aggregate European Data

    E-print Network

    Ahmad, Sajjad

    1 Inflation Targeting and Output Growth: Evidence from Aggregate European Data Nicholas Apergis inflation targeting and assesses its merits by comparing alternative targets in a macroeconomic model. We inflation targets in terms of output losses. We employ two major alternative policy rules, forward

  8. Cardiac tissue engineering using perfusion bioreactor systems

    PubMed Central

    Radisic, Milica; Marsano, Anna; Maidhof, Robert; Wang, Yadong; Vunjak-Novakovic, Gordana

    2009-01-01

    This protocol describes tissue engineering of synchronously contractile cardiac constructs by culturing cardiac cell populations on porous scaffolds (in some cases with an array of channels) and bioreactors with perfusion of culture medium (in some cases supplemented with an oxygen carrier). The overall approach is ‘biomimetic’ in nature as it tends to provide in vivo-like oxygen supply to cultured cells and thereby overcome inherent limitations of diffusional transport in conventional culture systems. In order to mimic the capillary network, cells are cultured on channeled elastomer scaffolds that are perfused with culture medium that can contain oxygen carriers. The overall protocol takes 2–4 weeks, including assembly of the perfusion systems, preparation of scaffolds, cell seeding and cultivation, and on-line and end-point assessment methods. This model is well suited for a wide range of cardiac tissue engineering applications, including the use of human stem cells, and high-fidelity models for biological research. PMID:18388955

  9. Cardiac muscle cells

    NSDL National Science Digital Library

    Nathanael Reveal (None; )

    2007-07-02

    Cardiac muscles are found only in the heart. They work together to bring deoxygenated blood in and push oxygenated blood out into the body. Essentially, they keep your heart pumping and your body alive.

  10. What Is Cardiac Rehabilitation?

    MedlinePLUS

    ... special help in making lifestyle changes. During your rehabilitation program you’ll… • Have a medical evaluation to ... rate, blood pressure and EKG monitored. A cardiac rehabilitation (rehab) program takes place in a hospital or ...

  11. Cardiopulmonary resuscitation and management of cardiac arrest.

    PubMed

    Nolan, Jerry P; Soar, Jasmeet; Wenzel, Volker; Paal, Peter

    2012-09-01

    The best chance of survival with a good neurological outcome after cardiac arrest is afforded by early recognition and high-quality cardiopulmonary resuscitation (CPR), early defibrillation of ventricular fibrillation (VF), and subsequent care in a specialist center. Compression-only CPR should be used by responders who are unable or unwilling to perform mouth-to-mouth ventilations. After the first defibrillator shock, further rhythm checks and defibrillation attempts should be performed after 2 min of CPR. The underlying cause of cardiac arrest can be identified and treated during CPR. Drugs have a limited effect on long-term outcomes after cardiac arrest, although epinephrine improves the success of resuscitation, and amiodarone increases the success of defibrillation for refractory VF. Supraglottic airway devices are an alternative to tracheal intubation, which should be attempted only by skilled rescuers. Care after cardiac arrest includes controlled reoxygenation, therapeutic hypothermia for comatose survivors, percutaneous coronary intervention, circulatory support, and control of blood-glucose levels and seizures. Prognostication in comatose survivors of cardiac arrest needs a careful, multimodal approach using clinical and electrophysiological assessments after at least 72 h. PMID:22665327

  12. Cardiac Origins of the Postural Orthostatic Tachycardia Syndrome

    PubMed Central

    Fu, Qi; VanGundy, Tiffany B.; Galbreath, M. Melyn; Shibata, Shigeki; Jain, Manish; Hastings, Jeffrey L.; Bhella, Paul S.; Levine, Benjamin D.

    2010-01-01

    Objectives To test the hypothesis that a small heart coupled with reduced blood volume contributes to the Postural Tachycardia Syndrome (POTS), while exercise training improves this syndrome. Background Patients with POTS have marked increases in heart rate during orthostasis. However, the underlying mechanisms are unknown and the effective therapy is uncertain. Methods Twenty-seven POTS patients underwent autonomic function tests, cardiac MRI, and blood volume measurements. Twenty-five of them participated in a 3-mo specially designed exercise training program with 19 completing the program; these patients were reevaluated after training. Results were compared with those of 16 healthy controls. Results Upright heart rate and total peripheral resistance were greater, while stroke volume and cardiac output were smaller in patients than controls. Baroreflex function was similar between groups. Left ventricular mass (median [25%, 75%], 1.26 [1.12, 1.37] vs 1.45 [1.34, 1.57] g/kg; P<0.01) and blood volume (60 [54, 64] vs 71 [65, 78] ml/kg; P<0.01) were smaller in patients than controls. Exercise training increased left ventricular mass and blood volume by ~12% and ~7%, and decreased upright heart rate by 9 [1, 17] bpm. Ten out of 19 patients no longer met POTS criteria after training, while patients’ Quality of Life assessed by Short-Form 36 was improved in all patients after training. Conclusions Autonomic function was intact in POTS patients. The marked tachycardia during orthostasis was attributable to a small heart coupled with reduced blood volume. Exercise training improved or even cured this syndrome in the majority of patients. It seems reasonable to offer POTS a new name based on its underlying pathophysiology – “The Grinch Syndrome”, because in this famous children’s book by Dr. Seuss, the main character had a heart that was “two sizes too small.” PMID:20579544

  13. Cardiac Rehabilitation After Acute Myocardial Infarction Resuscitated From Cardiac Arrest

    PubMed Central

    Kim, Chul; Choi, Hee Eun; Kang, Seong Hoon

    2014-01-01

    Objective To examine the safety and effectiveness of cardiac rehabilitation on patients resuscitated from cardiac arrest due to acute myocardial infarction. Methods The study included 23 subjects, including 8 with history of cardiac arrest and 15 without history of cardiac arrest. Both groups underwent initial graded exercise test (GXT) and subsequent cardiac rehabilitation for 6 weeks. After 6 weeks, both groups received follow-up GXT. Results Statistically significant (p<0.05) increase of VO2peak and maximal MVO2 but significant (p<0.05) decrease of submaximal MVO2 and resting heart rate were observed in both groups after 6 weeks of cardiac rehabilitation. An increasing trend of maximal heart rates was observed in both groups. However, the increase was not statistically significant (p>0.05). There was no statistically significant change of resting heart rate, maximal heart rate, maximal MVO2, or submaximal MVO2 in both groups after cardiac rehabilitation. Fatal cardiac complications, such as abnormal ECG, cardiac arrest, death or myocardial infarction, were not observed. All subjects finished the cardiac rehabilitation program. Conclusion Improvement was observed in the exercise capacity of patients after aerobic exercise throughout the cardiac rehabilitation program. Therefore, cardiac rehabilitation can be safely administered for high-risk patients with history of cardiac arrest. Similar improvement in exercise capacity can be expected in patients without cardiac arrest experience. PMID:25566479

  14. Cardiac ferroportin regulates cellular iron homeostasis and is important for cardiac function.

    PubMed

    Lakhal-Littleton, Samira; Wolna, Magda; Carr, Carolyn A; Miller, Jack J J; Christian, Helen C; Ball, Vicky; Santos, Ana; Diaz, Rebeca; Biggs, Daniel; Stillion, Richard; Holdship, Philip; Larner, Fiona; Tyler, Damian J; Clarke, Kieran; Davies, Benjamin; Robbins, Peter A

    2015-03-10

    Iron is essential to the cell. Both iron deficiency and overload impinge negatively on cardiac health. Thus, effective iron homeostasis is important for cardiac function. Ferroportin (FPN), the only known mammalian iron-exporting protein, plays an essential role in iron homeostasis at the systemic level. It increases systemic iron availability by releasing iron from the cells of the duodenum, spleen, and liver, the sites of iron absorption, recycling, and storage respectively. However, FPN is also found in tissues with no known role in systemic iron handling, such as the heart, where its function remains unknown. To explore this function, we generated mice with a cardiomyocyte-specific deletion of Fpn. We show that these animals have severely impaired cardiac function, with a median survival of 22 wk, despite otherwise unaltered systemic iron status. We then compared their phenotype with that of ubiquitous hepcidin knockouts, a recognized model of the iron-loading disease hemochromatosis. The phenotype of the hepcidin knockouts was far milder, with normal survival up to 12 mo, despite far greater iron loading in the hearts. Histological examination demonstrated that, although cardiac iron accumulates within the cardiomyocytes of Fpn knockouts, it accumulates predominantly in other cell types in the hepcidin knockouts. We conclude, first, that cardiomyocyte FPN is essential for intracellular iron homeostasis and, second, that the site of deposition of iron within the heart determines the severity with which it affects cardiac function. Both findings have significant implications for the assessment and treatment of cardiac complications of iron dysregulation. PMID:25713362

  15. Effect of prolonged exercise in a hypoxic environment on cardiac function and cardiac troponin T

    PubMed Central

    Shave, R; Dawson, E; Whyte, G; George, K; Gaze, D; Collinson, P

    2004-01-01

    Objective: To investigate if exercise induced cardiac fatigue and or cardiac damage occurs after prolonged exercise in a hypoxic environment. Methods: Eight trained male triathletes volunteered for the study. Each completed two 50 mile cycle trials, randomly assigned from normobaric normoxia and normobaric hypoxia (15% FIO2). Echocardiographic assessment and whole blood collection was completed before, immediately after, and 24 hours after exercise. Left ventricular systolic and diastolic functional variables were calculated, and serum was analysed for cardiac troponin T. Results were analysed using a two way repeated measures analysis of variance, with ? set at 0.05. Results: No significant differences were observed in either systolic or diastolic function across time or between trials. Cardiac troponin T was detected in one subject immediately after exercise in the normobaric hypoxic trial. Conclusions: A 50 mile cycle trial in either normobaric normoxia or normobaric hypoxia does not induce exercise induced cardiac fatigue. Some people, however, may exhibit minimal cardiac damage after exercise in normobaric hypoxia. The clinical significance of this is yet to be elucidated. PMID:14751955

  16. Impairment of cardiac function and energetics in experimental renal failure.

    PubMed Central

    Raine, A E; Seymour, A M; Roberts, A F; Radda, G K; Ledingham, J G

    1993-01-01

    Cardiac function and energetics in experimental renal failure in the rat (5/6 nephrectomy) have been investigated by means of an isolated perfused working heart preparation and an isometric Langendorff preparation using 31P nuclear magnetic resonance (31P NMR). 4 wk after nephrectomy cardiac output of isolated hearts perfused with Krebs-Henseleit buffer was significantly lower (P < 0.0001) at all levels of preload and afterload in the renal failure groups than in the pair-fed sham operated control group. In control hearts, cardiac output increased with increases in perfusate calcium from 0.73 to 5.61 mmol/liter whereas uremic hearts failed in high calcium perfusate. Collection of 31P NMR spectra from hearts of renal failure and control animals during 30 min normoxic Langendorff perfusion showed that basal phosphocreatine was reduced by 32% to 4.7 mumol/g wet wt (P < 0.01) and the phosphocreatine to ATP ratio was reduced by 32% (P < 0.01) in uremic hearts. During low flow ischemia, there was a substantial decrease in phosphocreatine in the uremic hearts and an accompanying marked increase in release of inosine into the coronary effluent (14.9 vs 6.1 microM, P < 0.01). We conclude that cardiac function is impaired in experimental renal failure, in association with abnormal cardiac energetics and increased susceptibility to ischemic damage. Disordered myocardial calcium utilization may contribute to these derangements. PMID:8254048

  17. Predictive value of the stomach wall pH for complications after cardiac operations: comparison with other monitoring

    Microsoft Academic Search

    Richard G. Fiddian-Green; Stephen P. Baker

    1987-01-01

    The ability to predict impending complications after elective cardiac operations from measurements of BP, cardiac index, arterial pH, and urine output on the day of operation was compared with that of indirect measurement of stomach wall pH in 85 patients. We found that acidosis in the stomach wall was the most sensitive predictor for complications. The specificity of this predictive

  18. A comparison between cardiac index and circulatory index in the dog during exercise and during infusion of isoproterenol

    E-print Network

    Smith, Thomas Lowell

    1975-01-01

    , exercise is now commonly imposed in a controlled, graded manner through the use of variable speed, variable pitch treadmills. William Cabitt, a British civil engineer, devised a elongated "stepping wheel" in 1818 which was used as a method of exercise... output. Proposed alternatives to the cardiac index include maximal oxygen uptake (42, 47, 54), a contractility index (46), a system for calculation of linear representations of cardiac output (1, 6), as well as the circulatory index as proposed...

  19. Echo-driven V-V optimization determines clinical improvement in non responders to cardiac resynchronization treatment.

    PubMed

    Naqvi, Tasneem Z; Rafique, Asim M; Peter, C Thomas

    2006-01-01

    Echocardiography plays an integral role in the detection of mechanical dyssynchrony in patients with congestive heart failure and in predicting beneficial response to cardiac resynchronization treatment. In patients who derive sup-optimal benefit from biventricular pacing, optimization of atrioventricular delay post cardiac resynchronization treatment has been shown to improve cardiac output. Some recent reports suggest that sequential ventricular pacing may further improve cardiac output. The mechanism whereby sequential ventricular pacing improves cardiac output is likely improved inter and possibly intraventricular synchrony, however these speculations have not been confirmed. In this report we describe the beneficial effect of sequential V-V pacing on inter and intraventricular synchrony, cardiac output and mitral regurgitation severity as the mechanisms whereby sequential biventricular pacing improves cardiac output and functional class in 8 patients who had derived no benefit or had deteriorated after CRT. Online tissue Doppler imaging including tissue velocity imaging, tissue synchronization imaging and strain and strain rate imaging were used in addition to conventional pulsed wave and color Doppler during sequential biventricular pacemaker programming. PMID:17049099

  20. Direct Cardiac Reprogramming: Advances in Cardiac Regeneration

    PubMed Central

    Chen, Olivia; Qian, Li

    2015-01-01

    Heart disease is one of the lead causes of death worldwide. Many forms of heart disease, including myocardial infarction and pressure-loading cardiomyopathies, result in irreversible cardiomyocyte death. Activated fibroblasts respond to cardiac injury by forming scar tissue, but ultimately this response fails to restore cardiac function. Unfortunately, the human heart has little regenerative ability and long-term outcomes following acute coronary events often include chronic and end-stage heart failure. Building upon years of research aimed at restoring functional cardiomyocytes, recent advances have been made in the direct reprogramming of fibroblasts toward a cardiomyocyte cell fate both in vitro and in vivo. Several experiments show functional improvements in mouse models of myocardial infarction following in situ generation of cardiomyocyte-like cells from endogenous fibroblasts. Though many of these studies are in an early stage, this nascent technology holds promise for future applications in regenerative medicine. In this review, we discuss the history, progress, methods, challenges, and future directions of direct cardiac reprogramming.

  1. Lightweight multiple output converter development

    NASA Technical Reports Server (NTRS)

    Kisch, J. J.; Martinelli, R. M.

    1978-01-01

    A high frequency, multiple output power conditioner was developed and breadboarded using an eight-stage capacitor diode voltage multiplier to provide +1200 Vdc, and a three-stage for -350 Vdc. In addition, two rectifier bridges were capacitively coupled to the eight-stage multiplier to obtain 0.5 and 0.65 a dc constant current outputs referenced to +1200 Vdc. Total power was 120 watts, with an overall efficiency of 85 percent at the 80 kHz operating frequency. All outputs were regulated to three percent or better, with complete short circuit protection. The power conditioner component weight and efficiency were compared to the equivalent four outputs of the 10 kHz conditioner for the 8 cm ion engine. Weight reduction for the four outputs was 557 grams; extrapolated in the same ratio to all nine outputs, it would be 1100 to 1400 grams.

  2. The role of cardiac sympathetic innervation and skin thermoreceptors on cardiac responses during heat stress.

    PubMed

    Shibasaki, Manabu; Umemoto, Yasunori; Kinoshita, Tokio; Kouda, Ken; Ito, Tomoyuki; Nakamura, Takeshi; Crandall, Craig G; Tajima, Fumihiro

    2015-06-01

    The mechanism(s) for the changes in cardiac function during heat stress remain unknown. This study tested two unique hypotheses. First, sympathetic innervation to the heart is required for increases in cardiac systolic function during heat stress. This was accomplished by comparing responses during heat stress between paraplegics versus tetraplegics, with tetraplegics having reduced/absent cardiac sympathetic innervation. Second, stimulation of skin thermoreceptors contributes to cardiovascular adjustments that occur during heat stress in humans. This was accomplished by comparing responses during leg only heating between paraplegic versus able-bodied individuals. Nine healthy able-bodied, nine paraplegics, and eight tetraplegics participated in this study. Lower body (i.e., nonsensed area for para/tetraplegics) was heated until esophageal temperature had increased by ?1.0°C. Echocardiographic indexes of diastolic and systolic function were performed before and at the end of heat stress. The heat stress increased cardiac output in all groups, but the magnitude of this increase was attenuated in the tetraplegics relative to the able-bodied (1.3 ± 0.4 vs. 2.3 ± 1.0 l/min; P < 0.05). Diastolic function was maintained in all groups. Indexes of left atrial and ventricular systolic function were enhanced in the able-bodied, but did not change in tetraplegics, while these changes in paraplegics were attenuated relative to the able-bodied. These data suggest that the cardiac sympathetic innervation is required to achieve normal increases in cardiac systolic function during heat stress but not required to maintain diastolic function during this exposure. Second, elevated systolic function during heat stress primarily occurs as a result of increases in internal temperature, although stimulation of skin thermoreceptors may contribute. PMID:25795714

  3. Living cardiac tissue slices: an organotypic pseudo two-dimensional model for cardiac biophysics research.

    PubMed

    Wang, Ken; Terrar, Derek; Gavaghan, David J; Mu-U-Min, Razik; Kohl, Peter; Bollensdorff, Christian

    2014-08-01

    Living cardiac tissue slices, a pseudo two-dimensional (2D) preparation, have received less attention than isolated single cells, cell cultures, or Langendorff-perfused hearts in cardiac biophysics research. This is, in part, due to difficulties associated with sectioning cardiac tissue to obtain live slices. With moderate complexity, native cell-types, and well-preserved cell-cell electrical and mechanical interconnections, cardiac tissue slices have several advantages for studying cardiac electrophysiology. The trans-membrane potential (Vm) has, thus far, mainly been explored using multi-electrode arrays. Here, we combine tissue slices with optical mapping to monitor Vm and intracellular Ca(2+) concentration ([Ca(2+)]i). This combination opens up the possibility of studying the effects of experimental interventions upon action potential (AP) and calcium transient (CaT) dynamics in 2D, and with relatively high spatio-temporal resolution. As an intervention, we conducted proof-of-principle application of stretch. Mechanical stimulation of cardiac preparations is well-established for membrane patches, single cells and whole heart preparations. For cardiac tissue slices, it is possible to apply stretch perpendicular or parallel to the dominant orientation of cells, while keeping the preparation in a constant focal plane for fluorescent imaging of in-slice functional dynamics. Slice-to-slice comparison furthermore allows one to assess transmural differences in ventricular tissue responses to mechanical challenges. We developed and tested application of axial stretch to cardiac tissue slices, using a manually-controlled stretching device, and recorded Vm and [Ca(2+)]i by optical mapping before, during, and after application of stretch. Living cardiac tissue slices, exposed to axial stretch, show an initial shortening in both AP and CaT duration upon stretch application, followed in most cases by a gradual prolongation of AP and CaT duration during stretch maintained for up to 50 min. After release of sustained stretch, AP duration (APD) and CaT duration reverted to shorter values. Living cardiac tissue slices are a promising experimental model for the study of cardiac mechano-electric interactions. The methodology described here can be refined to achieve more accurate control over stretch amplitude and timing (e.g. using a computer-controlled motorised stage, or by synchronising electrical and mechanical events) and through monitoring of regional tissue deformation (e.g. by adding motion tracking). PMID:25124067

  4. Isolated left ventricular assist as bridge to cardiac transplantation.

    PubMed

    Starnes, V A; Oyer, P E; Portner, P M; Ramasamy, N; Miller, P J; Stinson, E B; Baldwin, J C; Ream, A K; Wyner, J; Shumway, N E

    1988-07-01

    The electrically driven Novacor implantable left ventricular assist device has been implanted in six patients (four men and two women) since Sept. 7, 1984. In four of the six patients (67%) the device was a successful bridge to cardiac transplantation. One patient died of multiple organ failure and Candida sepsis after 16 days of support with the device. One patient died in the operating room of uncontrollable hemorrhage and biventricular failure caused by severe cardiac rejection. Three patients are alive with cardiac transplants 38, 17, and 10 months after transplantation. One patient died after cardiac transplantation of presumed sepsis. The Novacor left ventricular assist device performed in all cases without mechanical or electrical failure. Excluding the intraoperative death, assist duration ranged from 2 to 16 days. The cardiac index (synonymous with device output) ranged from 2.4 to 3.4 L/min/m2. No embolic events (cerebrovascular or systemic) occurred during assistance with the device. Minimal red cell hemolysis was documented during the period of support. The Novacor left ventricular assist device is a safe and effective bridge to cardiac transplantation in patients with refractory cardiogenic shock. PMID:3290589

  5. [Obesity and cardiac failure].

    PubMed

    Galinier, M; Pathak, A; Roncalli, J; Massabuau, P

    2005-01-01

    Obesity alone is the cause of 11% of cases of cardiac failure in men and 14% of cases in women in the United States. The frequency of obesity continues to rise in our country, 41% of our compatriots being obese or overweight. It is expected that obesity will become an important cause of cardiac failure in the coming years. The Framingham study showed that, after correction for other risk factors, for every point increase in body mass index, the increase in risk of developing cardiac failure was 5% in men and 7% in women. There are three physiopathological mechanisms to explain the adverse effects of obesity on left ventricular function: an increase in ventricular preload secondary to increased plasma volume induced by the high fatty mass; an increase in left ventricular afterload due to the common association of hypertension generated by activation of the sympathetic nervous system by hyperinsulinism; and systolic and diastolic dysfunction due to changes in the myocardial genome and coronary artery disease induced by risk factors of atherosclerosis aggravated by obesity. The adipocyte also secretes a number of hormones which act directly or indirectly on the myocardium: angiotensin II, leptin, resistin, adrenomedulin, cytokines. These haemodynamic and hormonal changes profoundly modify the genetic expression of the myocardium in obesity, favourising hypertrophy of the myocyte and the development of interstitial fibrosis. Whether it be eccentric in the absence of hypertension or concentric when hypertension is associated with obesity, left ventricular hypertrophy, although normalising left ventricular wall stress, has adverse consequences causing abnormal relaxation and decreased left ventricular compliance. Therefore, in obese patients, two forms of cardiac failure may be observed. The more common is due to diastolic dysfunction, obesity being one of the principal causes of cardiac failure with preserved systolic function. Cardiac failure due to systolic dysfunction is less common and may be observed in cases with inappropriate left ventricular hypertrophy which does not normalise abnormal left ventricular wall stress leading to cardiomyopathy, and in cases with associated coronary artery disease. Whatever the underlying mechanism, the diagnosis of cardiac failure is made more difficult by obesity. From the prognostic point of view, in the global population of patients with cardiac failure, obesity improves survival because it counteracts the adverse effect of cachexia; however, obesity increases the risk of sudden death. In fact, obesity is associated with dynamic change in QT interval. In cases of cardiac failure secondary to obesity-related cardiomyopathy, loss of weight leads to an improved functional status and a reduction of left ventricular remodelling and an increase of the ejection fraction. PMID:15724418

  6. Assessment of Myocardial Reactivity to Controlled Hypercapnia with Free-breathing T2-prepared Cardiac Blood Oxygen Level–Dependent MR Imaging

    PubMed Central

    Yang, Hsin-Jung; Yumul, Roya; Tang, Richard; Cokic, Ivan; Klein, Michael; Kali, Avinash; Sobczyk, Olivia; Sharif, Behzad; Tang, Jun; Bi, Xiaoming; Tsaftaris, Sotirios A.; Li, Debiao; Conte, Antonio Hernandez; Fisher, Joseph A.

    2014-01-01

    Purpose To examine whether controlled and tolerable levels of hypercapnia may be an alternative to adenosine, a routinely used coronary vasodilator, in healthy human subjects and animals. Materials and Methods Human studies were approved by the institutional review board and were HIPAA compliant. Eighteen subjects had end-tidal partial pressure of carbon dioxide (PetCO2) increased by 10 mm Hg, and myocardial perfusion was monitored with myocardial blood oxygen level–dependent (BOLD) magnetic resonance (MR) imaging. Animal studies were approved by the institutional animal care and use committee. Anesthetized canines with (n = 7) and without (n = 7) induced stenosis of the left anterior descending artery (LAD) underwent vasodilator challenges with hypercapnia and adenosine. LAD coronary blood flow velocity and free-breathing myocardial BOLD MR responses were measured at each intervention. Appropriate statistical tests were performed to evaluate measured quantitative changes in all parameters of interest in response to changes in partial pressure of carbon dioxide. Results Changes in myocardial BOLD MR signal were equivalent to reported changes with adenosine (11.2% ± 10.6 [hypercapnia, 10 mm Hg] vs 12% ± 12.3 [adenosine]; P = .75). In intact canines, there was a sigmoidal relationship between BOLD MR response and PetCO2 with most of the response occurring over a 10 mm Hg span. BOLD MR (17% ± 14 [hypercapnia] vs 14% ± 24 [adenosine]; P = .80) and coronary blood flow velocity (21% ± 16 [hypercapnia] vs 26% ± 27 [adenosine]; P > .99) responses were similar to that of adenosine infusion. BOLD MR signal changes in canines with LAD stenosis during hypercapnia and adenosine infusion were not different (1% ± 4 [hypercapnia] vs 6% ± 4 [adenosine]; P = .12). Conclusion Free-breathing T2-prepared myocardial BOLD MR imaging showed that hypercapnia of 10 mm Hg may provide a cardiac hyperemic stimulus similar to adenosine. © RSNA, 2014 Online supplemental material is available for this article. PMID:24749715

  7. Relation between N-terminal pro-brain natriuretic peptide and cardiac remodeling and function assessed by cardiovascular magnetic resonance imaging in patients with arrhythmogenic right ventricular cardiomyopathy.

    PubMed

    Cheng, Huaibing; Lu, Minjie; Hou, Cuihong; Chen, Xuhua; Wang, Jing; Yin, Gang; Chu, Jianmin; Zhang, Shu; Prasad, Sanjay K; Pu, Jielin; Zhao, Shihua

    2015-02-01

    Although N-terminal pro-brain natriuretic peptide (NT-proBNP) is a useful screening test of impaired right ventricular (RV) function in conditions affecting the right-sided cardiac muscle, the role of NT-proBNP remains unclear in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC). This study was designed to clarify the relation between the plasma NT-proBNP level and the RV function evaluated by cardiovascular magnetic resonance (CMR) imaging. We selected 56 patients with confirmed ARVC only when their blood specimens for NT-proBNP measurements were collected within 48 hours of a CMR scan. The NT-proBNP level was significantly higher in patients with RV dysfunction than in patients without RV dysfunction (median of 655.3 [interquartile range 556.4 to 870.0] vs 347.0 [interquartile range 308.0 to 456.2] pmol/L, p <0.001). The NT-proBNP levels were positively correlated with RV end-diastolic and end-systolic volume indices (r = 0.49 and 0.70, respectively) and negatively correlated with RV ejection fraction (r = -0.76, all p <0.001), which remained significant after adjustment for age, gender, and body mass index. The area under the receiver-operating characteristic curve for NT-proBNP was 0.91 (95% confidence interval 0.80 to 0.97, p <0.001). The cut-off value of NT-proBNP (458 pmol/L) was associated with sensitivity, specificity, and positive and negative predictive values of 91%, 89%, 67%, and 98%, respectively. In conclusion, NT-proBNP is a useful marker for the detection of RV dysfunction and associated with extent of RV dilatation and dysfunction determined by CMR in patients with ARVC. PMID:25523952

  8. Introduction to cardiac neuronal imaging: a clinical perspective.

    PubMed

    Jacobson, Arnold F; Narula, Jagat

    2015-06-01

    Procedures for noninvasive and minimally invasive imaging of cardiac neurons and neuronal function using radiolabeled compounds were developed in the second half of the 20th century. The foundation for these procedures was several centuries of research that identified the structural components of the autonomic nervous system and explored the means by which neurotransmitters such as acetylcholine and norepinephrine contributed to neuronal control of target organ effector cells. This article provides a brief clinical overview of modern approaches to the assessment of cardiac neurons as an introduction to the in-depth articles on the current status of cardiac neuronal imaging presented in this supplement. PMID:26033903

  9. Output coupler for laser resonator

    SciTech Connect

    Lundstrom, E.A.

    1984-07-17

    A laser output coupler utilizes a birefrigent lens which has one side thereof curved so as to present a non uniform polarization distribution across the face of the lens. A polarized beam splitter is employed to separate the output beam from the feedback beam; the feedback beam having a non uniform distribution across the laser aperture enhances mode discrimination of a pulsed resonator.

  10. Output coupler for laser resonator

    SciTech Connect

    Lundstrom, E.A.

    1981-09-15

    A laser output coupler utilizes a birefringent lens which has one side thereof curved so as to present a non-uniform polarization distribution across the face of the lens. A polarized beam splitter is employed to separate the output beam from the feedback beam; the feedback beam having a non uniform distribution across the laser aperture enhances mode discrimination of a pulsed resonator.

  11. PLA optimization using output encoding

    Microsoft Academic Search

    A. Saldanha; R. H. Katz

    1988-01-01

    An automatic tool that heuristically determines a good partitioning of a single large programmable logic array (PLA) into a PLA with a smaller number of encoded outputs (and usually fewer product terms), followed by a set of decoders to regenerate the original outputs, has been developed. Initial results using logic descriptions of processor chips and a benchmark set of industrial

  12. Influence of gravity on cardiac performance.

    PubMed

    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. PMID:9846932

  13. Drug Treatment of Cardiac Failure

    PubMed Central

    Achong, M. R.; Kumana, C. R.

    1982-01-01

    Treatment of cardiac failure should first be aimed at reversing or ameliorating the underlying pathological processes. This review highlights the common problems and pitfalls in the use of digoxin, diuretics and vasodilators in patients with cardiac failure. PMID:21289849

  14. Drug treatment of cardiac failure.

    PubMed

    Achong, M R; Kumana, C R

    1982-01-01

    Treatment of cardiac failure should first be aimed at reversing or ameliorating the underlying pathological processes. This review highlights the common problems and pitfalls in the use of digoxin, diuretics and vasodilators in patients with cardiac failure. PMID:21289849

  15. Sudden cardiac death.

    PubMed

    Kuriachan, Vikas P; Sumner, Glen L; Mitchell, L Brent

    2015-04-01

    Sudden death accounts for 300,000-400,000 deaths annually in the United States. Most sudden deaths are cardiac, and most sudden cardiac deaths are related to arrhythmias secondary to structural heart disease or primary electrical abnormalities of the heart. The most common structural disease leading to sudden death is ischemic heart disease. Nonischemic cardiomyopathy and other structural abnormalities such as arrhythmogenic ventricular dysplasia and hypertrophic cardiomyopathy may also be causative. Patients without structural disease have a primary electrical abnormality, such as long-QT syndrome or Brugada syndrome. Severe left ventricular systolic dysfunction is the main marker for sudden death in patients with ischemic or nonischemic cardiomyopathy. In other conditions, other markers for structural heart disease and electrical abnormalities need to be considered. It is seen that ?-blocker therapy is associated with a reduction in sudden cardiac death across a broad range of disorders. Nevertheless, the implantable cardioverter defibrillator remains the most effective treatment strategy in selected patients. PMID:25813838

  16. Primary cardiac tumors.

    PubMed Central

    Silverman, N A

    1980-01-01

    Cardiac tumors are a rare, but potentially curably form of heart disease. A high index of clinical suspicion is necessary for diagnosis as these tumors have protean manifestations that mimic a variety of other cardiac and noncardiac diseases. Presently, M-mode and two-dimensional echocardiography are utilized as safe, reliable, and noninvasive imaging modalities. Seventy-five per cent of these tumors are benign, with myxoma accounting for 50% and rhabodomyoma comprising 20% of lesions. Various histologic types of sarcoma are the predominant malignant cardiac neoplasms. With strict attention to avoiding perioperative tumor embolization, surgical resection of these lesions can be accomplished with minimal morbidity and mortality. Sixteen consecutive primary tumors of the heart have been surgically treated at Duke University Medical Center since 1966 with no perioperative deaths and no late recurrences. Images Figs. 2A and B. Fig. 3. Fig. 4. Figs. 5A and B Fig. 6. PMID:7362282

  17. Failed Weaning from Mechanical Ventilation and Cardiac Dysfunction

    PubMed Central

    Porhomayon, Jahan; Papadakos, Peter; Nader, Nader D.

    2012-01-01

    Failure to transition patient from controlled mechanical ventilation to spontaneous breathing trials (SBTs) in a timely fashion is associated with significant morbidity and mortality in the intensive care unit. In addition, weaning failures are common in patients with limited cardiac reserves. Recent advances in cardiac echocardiography and laboratory measurement of serum biomarkers to assess hemodynamic response to SBT may provide additional information to guide clinicians to predict weaning outcome. PMID:22991658

  18. Cardiac and lung complication probabilities after breast cancer irradiation

    Microsoft Academic Search

    Coen W Hurkmans; Jacques H Borger; Luc J Bos; Astrid van der Horst; Bradley R Pieters; Joos V Lebesque; Ben J Mijnheer

    2000-01-01

    Purpose: To assess for locoregional irradiation of breast cancer patients, the dependence of cardiac (cardiac mortality) and lung (radiation pneumonitis) complications on treatment technique and individual patient anatomy.Materials and methods: Three-dimensional treatment planning was performed for 30 patients with left-sided breast cancer and various breast sizes. Two locoregional techniques (Techniques A and B) and a tangential field technique, including only

  19. Cardiac autonomic function reveals adaptation to military training

    Microsoft Academic Search

    Jukka Huovinen; Heikki Kyrolainen; Vesa Linnamo; Minna Tanskanen; Hannu Kinnunen; Keijo Hakkinen; Mikko Tulppo

    2011-01-01

    The last 4 weeks of basic military training are very stressful. We tested the hypothesis that changes in cardiac autonomic function during this period are associated with changes in maximal oxygen uptake and\\/or serum hormonal concentrations in male conscripts (n=22). Cardiac vagal autonomic function was assessed by measuring the high-frequency (0.15–0.4 Hz) spectral power of R–R intervals. Maximal oxygen uptake

  20. The repeated sit-to-stand maneuver is a superior method for cardiac baroreflex assessment: a comparison with the modified Oxford method and Valsalva maneuver.

    PubMed

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

    2014-12-01

    Baroreflex assessment has diagnostic and prognostic utility in the clinical and research environments, and there is a need for a reliable, simple, noninvasive method of assessment. The repeated sit-to-stand method induces oscillatory changes in blood pressure (BP) at a desired frequency and is suitable for assessing dynamic baroreflex sensitivity (BRS). However, little is known about the reliability of this method and its ability to discern fundamental properties of the baroreflex. In this study we sought to: 1) evaluate the reliability of the sit-to-stand method for assessing BRS and compare its performance against two established methods (Oxford method and Valsalva maneuver), and 2) examine whether the frequency of the sit-to-stand method influences hysteresis. Sixteen healthy participants underwent three trials of each method. For the sit-to-stand method, which was performed at 0.1 and 0.05 Hz, BRS was quantified as an integrated response (BRSINT) and in response to falling and rising BP (BRSDOWN and BRSUP, respectively). Test retest reliability was assessed using the intraclass correlation coefficient (ICC). Irrespective of frequency, the ICC for BRSINT during the sit-to-stand method was ?0.88. The ICC for a rising BP evoked by phenylephrine (PEGAIN) in the Oxford method was 0.78 and ?0.5 for the remaining measures. During the sit-to-stand method, hysteresis was apparent in all participants at 0.1 Hz but was absent at 0.05 Hz. These findings indicate the sit-to-stand method is a statistically reliable BRS assessment tool and suitable for the examination of baroreflex hysteresis. Using this approach we showed that baroreflex hysteresis is a frequency-dependent phenomenon. PMID:25274908

  1. Cardiac Bioelectricity and Arrhythmias

    NSDL National Science Digital Library

    Flavio Fenton (Cornell University; )

    2006-09-22

    Deep inside a human heart, its pacemaker sends out bursts of electrical signals that keep the heart pumping rhythmically, supplying life-giving oxygen to the body. When these electrical waves become disorganized, the heart starts beating irregularly or arrhythmically. Flavio Fenton and Elizabeth Cherry of Cornell University made this interactive program to provide education on arrhythmias. It presents detailed information on cardiac anatomy, normal cardiac electrophysiology, and different kinds of arrhythmias using a combination of words, pictures, and interactive, computer simulations and animations.

  2. Cardiac Response and Personality Organization

    ERIC Educational Resources Information Center

    Blatt, Sidney J.; Feirstein, Alan

    1977-01-01

    This study examines the level and variability of cardiac response during complex problem-solving and interposed rest periods and their differing relationships to estimates of personality integration on the Rorschach. Findings suggest cardiac variability may be a more differentiated measure than level of cardiac response. (Author)

  3. Cardiac Xenotransplantation: Future and Limitations

    Microsoft Academic Search

    Kiyoshi Ogata; Jeffrey L. Platt

    2004-01-01

    Despite improvements in pharmacological therapies, the outlook for patients with severe cardiac disease remains poor. At present, only transplantation can ‘cure’ end-stage cardiac failure. However, fewer than 5% of those who need a cardiac transplant receive one in the United States each year. To address this problem, some propose using animals as a source of organs for transplantation, that is,

  4. Validation of European System for Cardiac Operative Risk Evaluation (EuroSCORE) in North American cardiac surgery

    Microsoft Academic Search

    Samer A. M Nashef; Francois Roques; Bradley G Hammill; Eric D Peterson; Philippe Michel; Frederick L Grover; Richard K. H Wyse; T. Bruce Ferguson

    2002-01-01

    Objective: To assess the performance of the European System for Cardiac Operative Risk Evaluation (EuroSCORE) when applied in a North American cardiac surgical population. Methods: The simple additive EuroSCORE model was applied to predict operative mortality (in-hospital or 30-day) in 401?684 patients undergoing coronary or valve surgery in 1998 and 1999 as well as in 188?913 patients undergoing surgery in

  5. Moore's law, Dabbawalas, and pediatric cardiac care in Sri Lanka

    PubMed Central

    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.

  6. Elevated miR499 Levels Blunt the Cardiac Stress Response

    Microsoft Academic Search

    Joseph T. C. Shieh; Yu Huang; Jacqueline Gilmore; Deepak Srivastava; Masa Tsuchiya

    2011-01-01

    BackgroundThe heart responds to myriad stresses by well-described transcriptional responses that involve long-term changes in gene expression as well as more immediate, transient adaptations. MicroRNAs quantitatively regulate mRNAs and thus may affect the cardiac transcriptional output and cardiac function. Here we investigate miR-499, a microRNA embedded within a ventricular-specific myosin heavy chain gene, which is expressed in heart and skeletal

  7. Cardiac Metabolic Alterations in Hypertensive Obese Pigs.

    PubMed

    Zhang, Xin; Li, Zi-Lun; Eirin, Alfonso; Ebrahimi, Behzad; Pawar, Aditya S; Zhu, Xiang-Yang; Lerman, Amir; Lerman, Lilach O

    2015-08-01

    Obesity and hypertension are major risk factors for cardiovascular diseases, and their growing coexistence accounts for an increase in adverse cardiac events, but the mechanisms are yet to be determined. We hypothesized that obesity exacerbates mitochondrial dysregulation imposed by hypertension and augments left ventricular dysfunction. Obesity-prone Ossabaw pigs were randomized to lean (standard diet) and obese (high-fat diet), without (Lean-sham and Obese-sham) or with renovascular hypertension (Lean-hypertension and Obese-hypertension), induced after 12 weeks of diet (n=7 each). Cardiac function, myocardial perfusion and oxygenation, and microvascular remodeling were assessed 4 weeks later. Mitochondrial biogenesis signals and structural proteins, respiratory chain complex activities, and mitochondrial self-degradation were examined, as was fibrosis. Obesity alone exerted no apparent effect on mitochondrial dynamics, but aggravated in hypertensive hearts the reduction of mitochondrial proteins, deoxyribonucleic acid content, and respiratory chain complex IV subunits activity, and amplified mitochondrial self-degradation. Synergistic interaction of obesity with hypertension also exacerbated myocardial fibrosis and left ventricular diastolic dysfunction. Mitochondrial content, respiratory chain complex IV subunits activity, and mitophagy were correlated with myocardial fibrosis. These findings suggest that obesity aggravates in renovascular hypertension cardiac mitochondrial aberrations. Mitochondrial function may regulate the progression of cardiac injury and functional deterioration in hypertension concomitant with obesity. PMID:26077566

  8. Cardiac imaging and stress testing asymptomatic athletes to identify those at risk of sudden cardiac death.

    PubMed

    La Gerche, Andre; Baggish, Aaron L; Knuuti, Juhani; Prior, David L; Sharma, Sanjay; Heidbuchel, Hein; Thompson, Paul D

    2013-09-01

    Sudden cardiac death in young athletes is rare but tragic. The cardiology community is faced with the challenge of providing a sensible strategy for the prevention of SCD while simultaneously reaffirming that the benefits of regular exercise far outweigh potential risks. At present, there is a broad range of screening recommendations dependent upon country, sporting discipline, and competition level. While much recent debate has focused on the efficacy of screening with electrocardiography, a number of sporting bodies also mandate the inclusion of exercise testing and echocardiography in screening protocols. Cardiac magnetic resonance imaging, coronary calcium scoring and computed tomography coronary angiography have also been promoted as potentially valuable screening tools for competitive athletes. This review will examine the controversial topic of utilizing cardiac imaging for athlete pre-participation screening. Specifically, the limitations of screening for relatively rare disorders using imaging tools with uncertain or imperfect accuracy will be addressed. Current evidence suggests that the accuracy of all cardiac imaging modalities is insufficient to justify their use as primary screening modalities in athletes. Atypical findings such as marked cardiac dilation, reduced deformation, or small patches of delayed gadolinium enhancement may be commonly encountered in well-trained athletes, but, at present, the prognostic significance of such findings is unknown. Resulting uncertainty for the clinician and athlete has the potential for psychological stress, further testing, and unnecessary exclusions from competition. However, these concerns must not be confused with the extremely useful applications of cardiac imaging for the assessment of athletes with symptoms, an abnormal electrocardiogram or a positive family history. As modern imaging further enhances our understanding of the spectrum of athlete's heart, its role may expand from the assessment of athletes with suspected disease to being part of comprehensive pre-participation screening in apparently healthy athletes. PMID:24029371

  9. Acoustic output measured by thermal and mechanical indices during fetal echocardiography at the time of the first trimester scan.

    PubMed

    Nemescu, Dragos; Berescu, Anca

    2015-01-01

    We measured acoustic output, expressed as the thermal index (TI) and mechanical index (MI), during fetal echocardiography at the time of the first trimester scan. TI and MI were retrieved from the saved displays during gray-mode, high-definition color flow Doppler and pulsed-wave Doppler (tricuspid flow) ultrasound examinations of the fetal heart and from the ductus venosus assessment. A total of 399 fetal cardiac examinations were evaluated. There was a significant increase in TI values from B-mode studies (0.07 ± 0.04 [mean ± SD]) to color flow mapping (0.2 ± 0.0) and pulsed-wave Doppler studies (0.36 ± 0.05). The TI from ductus venosus assessment (0.1 ± 0.01) was significantly lower than those from Doppler examinations of the heart. MI values from B-mode scans (0.65 ± 0.12) and color flow mapping (0.71 ± 0.11) were comparable, although different, and both values were higher than those from pulsed-wave Doppler tricuspid evaluation (0.39 ± 0.03). There were no differences in MI values from power Doppler assessment between the tricuspid flow and ductus venosus. Safety indices were remarkably stable and were largely constant, especially for color Doppler (TI), tricuspid flow (MI) and ductus venosus assessment (TI, MI). We acquired satisfactory Doppler images and/or signals at acoustic levels that were lower than the actual recommendations and never reached a TI of 0.5. PMID:25438839

  10. LF power of heart rate variability is not a measure of cardiac sympathetic tone but may be a measure of modulation of cardiac autonomic outflows by baroreflexes

    PubMed Central

    Goldstein, David S.; Bentho, Oladi; Park, Mee-Yeong; Sharabi, Yehonatan

    2011-01-01

    Power spectral analysis of heart rate variability (HRV) has been used frequently to assess cardiac autonomic function; however, the relationship of low frequency (LF) power of HRV to cardiac sympathetic tone has been unclear. With or without adjustment for high frequency (HF) power, total power, or respiration, LF power seems to provide an index not of cardiac sympathetic tone but of baroreflex function. Manipulations and drugs that change LF power or LF:HF may do so not by affecting cardiac autonomic outflows directly but by affecting modulation of those outflows by baroreflexes. PMID:21890520

  11. The cardiac muscle cell

    Microsoft Academic Search

    Nicholas J. Severs

    2000-01-01

    Summary The cardiac myocyte is the most physically energetic cell in the body, contracting constantly, without tiring, 3 billion times or more in an average human lifespan. By coordinating its beating activity with that of its 3 billion neighbours in the main pump of the human heart, over 7,000 litres of blood are pumped per day, without con- scious effort,

  12. Cardiac and Pulmonary Injury

    Microsoft Academic Search

    George C. Velmahos; Muhammad U. Butt

    2008-01-01

    Cardiac and pulmonary injuries present major chal- lenges in diagnosis and treatment. Distinct differences between penetrating and blunt trauma of these or- gans exist. Outcomes for severe injuries are still grave. Organized trauma systems can provide optimal care by minimizing prehospital time, allowing easy access to imaging modalities, and offering state-of-the-art treatment strategies. A multidisciplinary approach, including surgeons, intensivists, and

  13. Cardiac Physiology of Pregnancy.

    PubMed

    May, Linda

    2015-07-01

    Although the physiology of the heart and vascular system has not changed, there are many things we have learned and are still learning today. Research related to heart adaptations during pregnancy has been performed since the 1930s. Since the mid-1950s, researchers began to look at changes in the maternal cardiovascular system during exercise while pregnant. Research related to exercise during pregnancy and offspring heart development began and has continued since the 1970s. We will review the normal female cardiovascular system adaptations to pregnancy in general. Additionally, topics related to maternal cardiac adaptations to pregnancy during acute exercise, as well as the chronic conditioning response from exercise training will be explored. Since physical activity during pregnancy influences fetal development, the fetal cardiac development will be discussed in regards to acute and chronic maternal exercise. Similarly, the influence of various types of maternal exercise on acute and chronic fetal heart responses will be described. Briefly, the topics related to how and if there is maternal-fetal synchrony will be explained. Lastly, the developmental changes of the fetal cardiovascular system that persist after birth will be explored. Overall, the article will discuss maternal cardiac physiology related to changes with normal pregnancy, and exercise during pregnancy, as well as fetal cardiac physiology related to changes with normal development, and exercise during pregnancy as well as developmental changes in offspring after birth. © 2015 American Physiological Society. Compr Physiol 5:1325-1344, 2015. PMID:26140720

  14. Hepato-cardiac disorders

    PubMed Central

    Fouad, Yasser Mahrous; Yehia, Reem

    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 PMID:24653793

  15. Advanced Cardiac Life Support.

    ERIC Educational Resources Information Center

    Kirkwood Community Coll., Cedar Rapids, IA.

    This document contains materials for an advanced college course in cardiac life support developed for the State of Iowa. The course syllabus lists the course title, hours, number, description, prerequisites, learning activities, instructional units, required text, six references, evaluation criteria, course objectives by units, course…

  16. Output optics for laser velocimeters

    NASA Technical Reports Server (NTRS)

    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.

  17. Sensitive electrometer features digital output

    NASA Technical Reports Server (NTRS)

    Doong, H.

    1965-01-01

    Four-stage transistorized electrometer eliminates the need for a logarithmic compression network. It measures very low currents and produces a digital output directly indicative of the input current magnitude.

  18. Modeling Defense Budget Relationships with an Input-Output Model

    Microsoft Academic Search

    Mark A. Gallagher; Guenever L. R. Shariff

    2004-01-01

    The Department of Defense, like any major organization, must make many budget tradeoffs. Increasing funding for one program is often at the expense of another program. Senior decision-makers need an assessment of the resulting balance among various budget areas. We propose applying the Leontief input-output model to analyze the interrelationship between various budget areas and to assess the impacts of

  19. The Pathogenesis of Cardiac Fibrosis

    PubMed Central

    Kong, Ping; Christia, Panagiota; Frangogiannis, Nikolaos G

    2013-01-01

    Cardiac fibrosis is characterized by net accumulation of extracellular matrix proteins in the cardiac interstitium and contributes to both systolic and diastolic dysfunction in many cardiac pathophysiologic conditions. This review manuscript discusses the cellular effectors and molecular pathways implicated in the pathogenesis of cardiac fibrosis. Although activated myofibroblasts are the main effector cells in the fibrotic heart, monocytes/macrophages, lymphocytes, mast cells, vascular cells and cardiomyocytes may also contribute to the fibrotic response by secreting key fibrogenic mediators. Inflammatory cytokines and chemokines, reactive oxygen species, mast cell-derived proteases, endothelin-1, the renin/angiotensin/aldosterone system, matricellular proteins and growth factors (such as TGF-? and PDGF) are some of the best-studied mediators implicated in cardiac fibrosis. Both experimental and clinical evidence suggests that cardiac fibrotic alterations may be reversible. Understanding the mechanisms responsible for initiation, progression and resolution of cardiac fibrosis is crucial to design anti-fibrotic treatment strategies for patients with heart disease. PMID:23649149

  20. Genetics of sudden cardiac death.

    PubMed

    Bezzina, Connie R; Lahrouchi, Najim; Priori, Silvia G

    2015-06-01

    Sudden cardiac death occurs in a broad spectrum of cardiac pathologies and is an important cause of mortality in the general population. Genetic studies conducted during the past 20 years have markedly illuminated the genetic basis of the inherited cardiac disorders associated with sudden cardiac death. Here, we review the genetic basis of sudden cardiac death with a focus on the current knowledge on the genetics of the primary electric disorders caused primarily by mutations in genes encoding ion channels, and the cardiomyopathies, which have been attributed to mutations in genes encoding a broader category of proteins, including those of the sarcomere, the cytoskeleton, and desmosomes. We discuss the challenges currently faced in unraveling genetic factors that predispose to sudden cardiac death in the setting of sequela of coronary artery disease and present the genome-wide association studies conducted in recent years on electrocardiographic parameters, highlighting their potential in uncovering new biological insights into cardiac electric function. PMID:26044248

  1. Responsiveness of Health-Related Quality of Life Outcome Measures in Cardiac Rehabilitation: Comparison of Cardiac Rehabilitation Outcome Measures

    ERIC Educational Resources Information Center

    Hevey, David; McGee, Hannah M.; Horgan, John

    2004-01-01

    Assessment instruments that are not responsive to change are unsuitable as outcome tools in cardiac rehabilitation because they underestimate the psychosocial benefits of program attendance. Nine questionnaires were assessed for responsiveness with the standardized response mean (SRM). Questionnaires were allocated into 3 batteries, and each…

  2. Reverse Cardiac Remodeling: A Marker of Better Prognosis in Heart Failure

    PubMed Central

    Reis, José Rosino de Araújo Rocha; Cardoso, Juliano Novaes; Cardoso, Cristina Martins dos Reis; Pereira-Barretto, Antonio Carlos

    2015-01-01

    In heart failure syndrome, myocardial dysfunction causes an increase in neurohormonal activity, which is an adaptive and compensatory mechanism in response to the reduction in cardiac output. Neurohormonal activity is initially stimulated in an attempt to maintain compensation; however, when it remains increased, it contributes to the intensification of clinical manifestations and myocardial damage. Cardiac remodeling comprises changes in ventricular volume as well as the thickness and shape of the myocardial wall. With optimized treatment, such remodeling can be reversed, causing gradual improvement in cardiac function and consequently improved prognosis. PMID:25830713

  3. Utilization of the Organ Care System Lung for the assessment of lungs from a donor after cardiac death (DCD) before bilateral transplantation.

    PubMed

    Mohite, P N; Sabashnikov, A; García Sáez, D; Pates, B; Zeriouh, M; De Robertis, F; Simon, A R

    2015-07-01

    In this manuscript, we present the first experience of evaluating donation after circulatory death (DCD) lungs, using the normothermic preservation Organ Care System (OCS) and subsequent successful transplantation. The OCS could be a useful tool for the evaluation of marginal lungs from DCD donors as it allows a proper recruitment and bronchoscopy in such donations in addition to continuous ex-vivo perfusion and assessment and treatment during transport. The OCS could potentially be a standard of care in the evaluation of marginal lungs from DCD. PMID:25332197

  4. [The evaluation of prognostic value of biomarkers in patients with chronic cardiac insufficiency].

    PubMed

    Ro?tman, A P; Lysikov, O Iu; Bugrov, A V; Maksimova, I A; Dolgov, V V

    2014-07-01

    Nowadays, the laboratory markers of myocardial dysfunction (cerebral natriuretic peptide - NT-proBNP); instability of atherosclerotic plaque (highly sensitive C-reactive protein - hsCRP); damages of cardiac muscle (highly sensitive cardiac tropine I - hs-cTnl) play a key role in diagnostic, course prognostics and verification of risk of unfavorable outcomes in patients with chronic cardiac insufficiency. The article presents the results of study of dynamics of levels of NT-proBNP, hsCRP, hs-cTnl in 71 patients with chronic cardiac insufficiency of II and III functional class (according classification of New-York association of cardiologists - NYHA). The comparison was made concerning analyzed laboratory markers with fraction of output of left ventricle of heart and index of body mass relatively to their prognostic role inpatients with chronic cardiac insufficiency with different clinical conditions and various outcomes of disease. It is demonstrated that level of hs-cTnl is the most valuable in respect to unfavorable prognosis of course of chronic cardiac insufficiency and risk of lethal outcome. The level of NT-proBNP has invert correlation relationship with fraction of output of left ventricle of heart and can be considered as a laboratory indicator of functional condition of myocardium in patients with chronic cardiac insufficiency. PMID:25346981

  5. Prediction of cardiac risk in patients undergoing vascular surgery

    SciTech Connect

    Morise, A.P.; McDowell, D.E.; Savrin, R.A.; Goodwin, C.A.; Gabrielle, O.F.; Oliver, F.N.; Nullet, F.R.; Bekheit, S.; Jain, A.C.

    1987-03-01

    In an attempt to determine whether noninvasive cardiac testing could be used to assess cardiac risk in patients undergoing surgery for vascular disease, the authors studied 96 patients. Seventy-seven patients eventually underwent major vascular surgery with 11 (14%) experiencing a significant cardiac complication. Thallium imaging was much more likely to be positive (p less than 0.01) in patients with a cardiac complication; however, there was a significant number of patients with cardiac complications who had a positive history or electrocardiogram for myocardial infarction. When grouped by complication and history of infarction, thallium imaging, if negative, correctly predicted low cardiac risk in the group with a history of infarction. Thallium imaging, however, did not provide a clear separation of risk in those without a history of infarction. Age and coronary angiography, on the other hand, did reveal significant differences within the group without a history of infarction. The resting radionuclide ejection fraction followed a similar pattern to thallium imaging. It is concluded that a positive history of myocardial infarction at any time in the past is the strongest risk predictor in this population and that the predictive value of noninvasive testing is dependent on this factor. Considering these findings, a proposed scheme for assessing risk that will require further validation is presented.

  6. Prognostic Value of Estimated Functional Capacity Incremental to Cardiac Biomarkers in Stable Cardiac Patients

    PubMed Central

    Tang, W. H. Wilson; Topol, Eric J.; Fan, Yiying; Wu, Yuping; Cho, Leslie; Stevenson, Cindy; Ellis, Stephen G.; Hazen, Stanley L.

    2014-01-01

    Background Few studies have investigated functional capacity self?assessment tools in either prediction of future major adverse cardiac outcomes beyond all?cause mortality or direct comparisons with clinically available biomarkers. Methods and Results We estimated functional capacity using the Duke Activity Status Index (DASI) questionnaire in 8987 sequential stable patients without acute coronary syndrome who were undergoing elective diagnostic coronary angiography with 3?year follow?up of major adverse cardiac events (death, nonfatal myocardial infarction, or stroke). A low DASI score provided independent prediction of a 4.8?fold increase in future risk of incident major adverse cardiac events at 3 years (quartiles 1 versus 4 hazard ratio [95% CI] 4.76 [4.03 to 5.61], P<0.001), and a 3.8?fold increased risk after adjusting for traditional risk factors (3.77 [3.15 to 4.51], P<0.001). The prognostic value of the DASI score was evident in both primary and secondary prevention cohorts, with and without heart failure, as well as high and low C?reactive protein and B?type natriuretic peptide levels. The DASI score reclassified 15% of patients (P<0.001) beyond traditional risk factors in predicting future MACE. Conclusion A simple self?assessment tool of functional capacity in stable patients undergoing elective diagnostic cardiac evaluation provides independent and incremental prognostic value for prediction of both significant coronary angiographic disease and long?term adverse clinical events. PMID:25332177

  7. Imaging in adults with congenital cardiac disease (ACCD).

    PubMed

    Kaemmerer, H; Stern, H; Fratz, S; Prokop, M; Schwaiger, M; Hess, J

    2000-12-01

    Management of patients with congenital heart disease requires detailed information on cardiac and great vessel morphology. In previous years, the diagnosis and the treatment of congenital malformations has often depended on cardiac catherization, and in many institutions, cardiac catherization still remains the gold standard against which other modalities are measured. In the past decade, however, imaging methodologies have increasingly shifted toward the use of less invasive and noninvasive techniques. Currently, echocardiography is the initial method of choice in evaluating the anatomy, especially in younger patients. Meanwhile, several newer imaging techniques like magnetic resonance imaging (MRI) and spiral or multislice computed tomography (CT) are in use. They offer extremely useful information about abnormalities of the heart and great vessels as well as the assessment of cardiac anatomy and function. Echo, angiography, MRI and CT should be seen as complimentary investigations in adult congenital heart disease. PMID:11145399

  8. Network Reconstruction and Systems Analysis of Cardiac Myocyte Hypertrophy Signaling*

    PubMed Central

    Ryall, Karen A.; Holland, David O.; Delaney, Kyle A.; Kraeutler, Matthew J.; Parker, Audrey J.; Saucerman, Jeffrey J.

    2012-01-01

    Cardiac hypertrophy is managed by a dense web of signaling pathways with many pathways influencing myocyte growth. A quantitative understanding of the contributions of individual pathways and their interactions is needed to better understand hypertrophy signaling and to develop more effective therapies for heart failure. We developed a computational model of the cardiac myocyte hypertrophy signaling network to determine how the components and network topology lead to differential regulation of transcription factors, gene expression, and myocyte size. Our computational model of the hypertrophy signaling network contains 106 species and 193 reactions, integrating 14 established pathways regulating cardiac myocyte growth. 109 of 114 model predictions were validated using published experimental data testing the effects of receptor activation on transcription factors and myocyte phenotypic outputs. Network motif analysis revealed an enrichment of bifan and biparallel cross-talk motifs. Sensitivity analysis was used to inform clustering of the network into modules and to identify species with the greatest effects on cell growth. Many species influenced hypertrophy, but only a few nodes had large positive or negative influences. Ras, a network hub, had the greatest effect on cell area and influenced more species than any other protein in the network. We validated this model prediction in cultured cardiac myocytes. With this integrative computational model, we identified the most influential species in the cardiac hypertrophy signaling network and demonstrate how different levels of network organization affect myocyte size, transcription factors, and gene expression. PMID:23091058

  9. Cardiac adaptations of bullfrog tadpoles in response to chytrid infection.

    PubMed

    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. J. Exp. Zool. 323A: 487-496, 2015. © 2015 Wiley Periodicals, Inc. PMID:26055358

  10. Program Overview The Cardiac Sonography program prepares individuals to perform cardiac

    E-print Network

    Cheng, Mei-Fang

    and Physiology, Pathophysiology, Ultrasound Physics, Instrumentation and Applied Cardiac Sonography. ClinicalProgram Overview The Cardiac Sonography program prepares individuals to perform cardiac sonography hours. Program Description The Cardiac Sonography Program is located on the Scotch Plains campus

  11. Theory and in vitro validation of a new extracorporeal arteriovenous loop approach for hemodynamic assessment in pediatric and neonatal intensive care unit patients*

    PubMed Central

    Krivitski, Nikolai M.; Kislukhin, Victor V.; Thuramalla, Naveen V.

    2008-01-01

    Objectives No simple method exists for repeatedly measuring cardiac output in intensive care pediatric and neonatal patients. The purpose of this study is to present the theory and examine the in vitro accuracy of a new ultrasound dilution cardiac output measurement technology in which an extracorporeal arteriovenous tubing loop is inserted between existing arterial and venous catheters. Design Laboratory experiments. Setting Research laboratory. Subjects None. Interventions None. Measurements and Main Results In vitro validations of cardiac output, central blood volume, total end-diastolic volume, and active circulation volume were performed in a model mimicking pediatric (children 2-10 kg) and neonatal (0.5-3 kg) flows and volumes against flows and volumes measured volumetrically. Reusable sensors were clamped onto the arterial and venous limbs of the arteriovenous loop. A peristaltic pump was used to circulate liquid at 6-12 mL/min from the artery to the vein through the arteriovenous loop. Body temperature injections of isotonic saline (0.3-10 mL) were performed. In the pediatric setting, the absolute difference between cardiac output measured by dilution and cardiac output measured volumetrically was 3.97% ± 2.97% (range 212-1200 mL/min); for central blood volume the difference was 4.59% ± 3.14% (range 59-315 mL); for total end-diastolic volume the difference was 4.10% ± 3.08% (range 24-211 mL); and for active circulation volume the difference was 3.30% ± 3.07% (range 247-645 mL). In the neonatal setting the difference for cardiac output was 4.40% ± 4.09% (range 106-370 mL/min); for central blood volume the difference was 4.90% ± 3.69% (range 50-62 mL); and for active circulation volume the difference was 5.39% ± 4.42% (range 104-247 mL). Conclusions In vitro validation confirmed the ability of the ultrasound dilution technology to accurately measure small flows and volumes required for hemodynamic assessments in small pediatric and neonatal patients. Clinical studies are in progress to assess the reliability of this technology under different clinical situations. PMID:18496416

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

    NASA Technical Reports Server (NTRS)

    Bogomolov, V. V.; Duncan, J. M.; Alferova, I. V.; Dulchavsky, S. A.; Ebert, D.; Hamilton, D. R.; Matveev, V. P.; Sargsyan, A. E.

    2008-01-01

    Recent advances in remotely guided imaging techniques on ISS allow the acquisition of high quality ultrasound data using crewmember operators with no medical background and minimal training. However, ongoing efforts are required to develop and validate methodology for complex imaging protocols to ensure their repeatability, efficiency, and suitability for use aboard the ISS. This Station Developmental Test Objective (SDTO) tests a cardiovascular evaluation methodology that takes advantage of the ISS Ultrasound capability, the Braslet-M device, and modified respiratory maneuvers (Valsalva and Mueller), to broaden the spectrum of anatomical and functional information on human cardiovascular system during long-duration space missions. The proposed methodology optimizes and combines new and previously demonstrated methods, and is expected to benefit medically indicated assessments, operational research protocols, and data collections for science. Braslet-M is a current Russian operational countermeasure that compresses the upper thigh to impede the venous return from lower extremities. The goal of the SDTO is to establish and validate a repeatable ultrasound-based methodology for the assessment of a number of cardiovascular criteria in microgravity. Braslet-M device is used as a means to acutely alter volume distribution while focused ultrasound measurements are performed. Modified respiratory maneuvers are done upon volume manipulations to record commensurate changes in anatomical and functional parameters. The overall cardiovascular effects of the Braslet-M device are not completely understood, and although not a primary objective of this SDTO, this effort will provide pilot data regarding the suitability of Braslet-M for its intended purpose, effects, and the indications for its use.

  13. Cardiac arrest in children

    PubMed Central

    Tress, Erika E; Kochanek, Patrick M; Saladino, Richard A; Manole, Mioara D

    2010-01-01

    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

  14. Cardiac Resynchronization Therapy

    PubMed Central

    Owen, Joseph S.; Khatib, Sammy; Morin, Daniel P.

    2009-01-01

    Systolic heart failure is a major problem for Americans today, with 550,000 new cases diagnosed per year, and ultimately contributes to 287,000 deaths annually. While pharmacologic therapy has drastically improved outcomes in patients with systolic heart failure, hospitalizations from systolic heart failure continue to increase and remain a major cost burden. In response to this unmet need, recent years have seen dramatic improvements in device-based therapy targeting one cause of systolic dysfunction: dyssynchronous ventricular contraction. Cardiac resynchronization therapy aims to restore mechanical synchrony by electrically activating the heart in a synchronized manner. This review summarizes the rationale for cardiac resynchronization therapy, evidence for its use, current guidelines, and ongoing and future directions for research. PMID:21603451

  15. Blunt Cardiac Injury in the Severely Injured – A Retrospective Multicentre Study

    PubMed Central

    Hanschen, Marc; Kanz, Karl-Georg; Kirchhoff, Chlodwig; Khalil, Philipe N.; Wierer, Matthias; van Griensven, Martijn; Laugwitz, Karl-Ludwig; Biberthaler, Peter; Lefering, Rolf; Huber-Wagner, Stefan

    2015-01-01

    Background Blunt cardiac injury is a rare trauma entity. Here, we sought to evaluate the relevance and prognostic significance of blunt cardiac injury in severely injured patients. Methods In a retrospective multicentre study, using data collected from 47,580 patients enrolled to TraumaRegister DGU (1993-2009), characteristics of trauma, prehospital / hospital trauma management, and outcome analysis were correlated to the severity of blunt cardiac injury. The severity of cardiac injury was assessed according to the abbreviated injury score (AIS score 1-6), the revised injury severity score (RISC) allowed comparison of expected outcome with injury severity-dependent outcome. N = 1.090 had blunt cardiac trauma (AIS 1-6) (2.3% of patients). Results Predictors of blunt cardiac injury could be identified. Sternal fractures indicate a high risk of the presence of blunt cardiac injury (AIS 0 [control]: 3.0%; AIS 1: 19.3%; AIS 2-6: 19.1%). The overall mortality rate was 13.9%, minor cardiac injury (AIS 1) and severe cardiac injury (AIS 2-6) are associated with higher rates. Severe blunt cardiac injury (AIS 4 and AIS 5-6) is associated with a higher mortality (OR 2.79 and 4.89, respectively) as compared to the predicted average mortality (OR 2.49) of the study collective. Conclusion Multiple injured patients with blunt cardiac trauma are at high risk to be underestimated. Careful evaluation of trauma patients is able to predict the presence of blunt cardiac injury. The severity of blunt cardiac injury needs to be stratified according to the AIS score, as the patients’ outcome is dependent on the severity of cardiac injury. PMID:26136126

  16. Cardiac muscle tissue engineering

    Microsoft Academic Search

    Maria Papadaki

    2003-01-01

    Cell-based therapy has emerged as a novel approach for replacing heart muscle, which is known not to regenerate after injury such as that caused by infarction or reconstructive surgery. Two types of cell-based therapies have been employed: injection of isolated cells or the implantation of in-vitro-grown cardiac muscle tissue equivalents In the first case, several cell types - including skeletal

  17. Cardiac Arrest in Pregnancy

    Microsoft Academic Search

    Alison A. Rodriguez; Gary A. Dildy

    Cardiac arrest (CA) in pregnancy is an uncommon occurrence with an incidence of about 1 in every 30,000 deliveries (1). The causes are quite numerous, but the management is essentially the same with the exception of a few modifications regarding\\u000a the fetus. In this chapter, causes of maternal mortality are reviewed along with potential interventions to decrease its incidence.\\u000a A

  18. Delirium After Cardiac Surgery

    Microsoft Academic Search

    James L. Rudolph

    \\u000a Delirium is an acute change in cognitive functioning, characterized by inattention and associated with disorganized thinking\\u000a or altered level of consciousness, which preferentially affects the older patients (Diagnostic and statistical manual of mental\\u000a disorders, fourth edition, text revision. Washington: American Psychiatric Association; 2000). After cardiac surgery, the\\u000a incidence of delirium has been reported between 2 and 73%, depending on the

  19. Inflammation and Cardiac Outcome

    PubMed Central

    Hohensinner, P.J.; Niessner, A.; Huber, K.; Weyand, C.M.; Wojta, J

    2015-01-01

    Purpose of Review Inflammation is a key component in cardiovascular disease. Controlling inflammatory events and their subsequent processes hold the potential for novel therapeutic options. Cytokines are the propagators of inflammation. In this review we will discuss important cytokines, including IL-6, TNF-alpha, MCP-1, M-CSF and GDF-15 and their effect on cardiac outcome. Recent findings IL-6 is a useful biomarker in patients with coronary artery disease. Summary PMID:21378564

  20. Hypothermic Cardiac Arrest

    Microsoft Academic Search

    Daniel F. Danzl

    The contemporary allure of hypothermia is regularly sparked by the apparent “reanimations” of profoundly cold patients in\\u000a prolonged cardiac arrest (CA). Recently, a physician who was resuscitated from 13.7°C presented her own case report at an\\u000a international conference (1). There are also promising ongoing investigations of mild therapeutic hypothermia for traumatic intracranial hypertension\\u000a and stroke (2–4). Nevertheless, hypothermia remains more

  1. Cardiac transplantation. Selection, immunosuppression, and survival.

    PubMed Central

    Stevenson, L W; Laks, H; Terasaki, P I; Kahan, B D; Drinkwater, D C

    1988-01-01

    Cardiac transplantation has evolved from an experiment to an accepted therapy for severe heart failure. Increasing competition for donor organs mandates a greater emphasis on selection and timing for transplantation and paradoxically forces more reliance on aggressive medical therapy for all patients after evaluation. The growth of recipient and donor pools may enhance the opportunity for assessing histocompatibility, for which distinguishing between autoantibodies and human leukocyte antigen-determined reactivity is important, and some general nonresponders may be detected. Therapy with cyclosporine has improved the outcome after transplantation, but further refinement is needed, perhaps with pharmacologic synergy, to minimize nephrotoxicity and maximize specific immunosuppression. Survival is more than 80% at 1 year, after which the incidence of acute rejection and infection declines and accelerated atherosclerosis becomes prominent. Although resuming employment is not always possible, the overall quality of life is excellent after cardiac transplantation. Images PMID:3074557

  2. Cardiac regenerative medicine.

    PubMed

    Yuasa, Shinsuke; Fukuda, Keiichi

    2008-01-01

    Severe heart failure is associated with damage to the myocardium that is irreversible with current medical therapies. Recent experimental and clinical studies, however, have opened the possibility of solving many of the associated problems, making this an exciting and tangible goal. There are many potential cell sources for regenerative cardiac medicine, including bone marrow stem cells, endothelial progenitor cells, skeletal myocytes, adult cardiac stem cells, and embryonic stem (ES) cells. Although ES cells are highly proliferative and suitable for mass production, they are not autologous, and an efficient protocol is yet to be established to ensure selective cardiomyocyte induction. Recent studies have successfully established inducible pluripotent stem (iPS) cells from mouse and human fibroblasts by the gene transfer of 4 transcription factors that are strongly expressed in ES cells: Oct3/4, Sox2, Klf4 and c-Myc. iPS cells can differentiate into all 3 germ layer-derived cells and are syngeneic, indicating that they can become an ideal cell source for regenerative medicine. Despite these successes, the accumulating evidence from fields as diverse as developmental biology, stem cell biology and tissue engineering must be integrated to achieve the full potential of cardiac regenerative medicine. PMID:18772528

  3. Sudden cardiac death and obesity.

    PubMed

    Plourde, Benoit; Sarrazin, Jean-François; Nault, Isabelle; Poirier, Paul

    2014-09-01

    For individuals and the society as a whole, the increased risk of sudden cardiac death in obese patients is becoming a major challenge, especially since obesity prevalence has been increasing steadily around the globe. Traditional risk factors and obesity often coexist. Hypertension, diabetes, obstructive sleep apnea and metabolic syndrome are well-known risk factors for CV disease and are often present in the obese patient. Although the bulk of evidence is circumstantial, sudden cardiac death and obesity share common traditional CV risk factors. Structural, functional and metabolic factors modulate and influence the risk of sudden cardiac death in the obese population. Other risk factors such as left ventricular hypertrophy, increased number of premature ventricular complexes, altered QT interval and reduced heart rate variability are all documented in both obese and sudden cardiac death populations. The present review focuses on out-of-hospital sudden cardiac death and potential mechanisms leading to sudden cardiac death in this population. PMID:25160995

  4. Cardiac sarcoidosis: a comprehensive review

    PubMed Central

    Sekhri, Vishal; Sanal, Shireen; DeLorenzo, Lawrence J.; Aronow, Wilbert S.; Maguire, George P.

    2011-01-01

    Sarcoidosis is a multisystem granulomatous disease of unknown etiology characterized by noncaseating granulomas in involved organs. Organs involved with sarcoidosis include lymph nodes, skin, lung, central nervous system, and eye. Only 40-50% of patients with cardiac sarcoidosis diagnosed at autopsy have the diagnosis made during their lifetime. Cardiac sarcoidosis can manifest itself as complete heart block, ventricular arrhythmias, congestive heart failure, pericardial effusion, pulmonary hypertension, and ventricular aneurysms. Diagnostic tests such as the electrocardiogram, two-dimensional echocardiography, cardiac magnetic resonance imaging, positron emission tomography scan, radionuclide scan, and endomyocardial biopsy can be helpful in the early detection of cardiac sarcoidosis. Considering the increased risk of sudden death, cardiac sarcoidosis is an indication for early treatment with corticosteroids or other immunosuppressive agents. Other treatments include placement of a pacemaker or implantable defibrillator to prevent sudden death. In refractory cases, cardiac transplantation should be considered. PMID:22291785

  5. Cardiac Emergencies in Neurosurgical Patients

    PubMed Central

    Petropolis, Andrea; Cappellani, Ronald B.

    2015-01-01

    Perioperative safety concerns are a major area of interest in recent years. Severe cardiac perturbation such as cardiac arrest is one of the most dreaded complications in the intraoperative period; however, little is known about the management of these events in the patients undergoing elective neurosurgery. This special group needs further attention, as it is often neither feasible nor appropriate to apply conventional advanced cardiac life support algorithms in patients undergoing neurosurgery. Factors such as neurosurgical procedure and positioning can also have a significant effect on the occurrence of cardiac arrest. Therefore, the aim of this paper is to describe the various causes and management of cardiac emergencies with special reference to cardiac arrest during elective neurosurgical procedures, including discussion of position-related factors and resuscitative considerations in these situations. This will help to formulate possible guidelines for management of such events. PMID:25692145

  6. Effects of alprazolam and imipramine on parasympathetic cardiac control in patients with generalized anxiety disorder

    Microsoft Academic Search

    Daniel R. McLeod; Rudolf Hoehn-Saric; Stephen W. Porges; Wesley D. Zimmerli

    1992-01-01

    A noninvasive measure was used to assess the effects of alprazolam, imipramine and placebo on parasympathetic (vagal) cardiac control following 6-weeks of medication in patients with generalized anxiety disorder. Flexible dosage at therapeutic levels resulted in increased heart rate and blood pressure and in decreased cardiac vagal control in patients receiving imipramine but not alprazolam or placebo. About 50% of

  7. Clinical course and medical management of neonates with severe cardiac failure related to vein of Galen malformation

    PubMed Central

    Frawley, G; Dargaville, P; Mitchell, P; Tress, B; Loughnan, P

    2002-01-01

    Background: Neonatal presentation of vein of Galen aneurysmal malformations (VGAMs) with intractable cardiac failure is considered a poor prognostic sign. Interventional neuroradiology with embolisation has been shown to control cardiac failure, but there is a perception that neurological outcome in survivors is poor. Objective: To determine if aggressive intensive care and anaesthetic management of cardiac failure before urgent embolisation can influence morbidity and mortality. Patients: Nine newborns (four boys, five girls) were diagnosed with symptomatic vein of Galen malformations in the neonatal period during the period 1996–2001. Eight developed intractable high output cardiac failure requiring initial endovascular treatment in the first week of life. Results: The immediate outcome after a series of endovascular procedures was control of cardiac failure and normal neurological function in six (66%) patients, one death from intractable cardiac failure in the neonatal period, and two late deaths with severe hypoxic-ischaemic neurological injury (33% mortality). Clinical review at 6 months to 4 years of age showed five infants with no evidence of neurological abnormality or cardiac failure and one child with mild developmental delay (11%). Conclusions: Aggressive medical treatment of cardiac failure and early neurointervention combined with modern neuroanaesthetic care results in good survival rates with low morbidity even in cases of high risk VGAM presenting in the immediate perinatal period with cardiac failure. Systemic arterial vasodilators improve outcome in neonates with cardiac failure secondary to VGAM. Excessive ß adrenergic stimulation induced by conventional inotropic agents may exacerbate systemic hypoperfusion. PMID:12193525

  8. Sudden cardiac death – Historical perspectives

    PubMed Central

    Abhilash, S.P.; Namboodiri, Narayanan

    2014-01-01

    Sudden cardiac death (SCD) is an unexpected death due to cardiac causes that occurs in a short time period (generally within 1 h of symptom onset) in a person with known or unknown cardiac disease. It is believed to be involved in nearly a quarter of human deaths, with ventricular fibrillation being the most common mechanism. It is estimated that more than 7 million lives per year are lost to SCD worldwide. Historical perspectives of SCD are analyzed with a brief description on how the developments in the management of sudden cardiac arrest evolved over time. PMID:24568828

  9. Registry of Unexplained Cardiac Arrest

    ClinicalTrials.gov

    2015-04-13

    Cardiac Arrest; Long QT Syndrome; Brugada Syndrome; Catecholaminergi Polymorphic Ventricular Tachycardia; Idiopathic VentricularFibrillation; Early Repolarization Syndrome; Arrhythmogenic Right Ventricular Cardiomyopathy

  10. What to Expect during Cardiac Rehabilitation

    MedlinePLUS

    ... NHLBI on Twitter. What To Expect During Cardiac Rehabilitation During cardiac rehabilitation (rehab), you'll learn how to: Increase your ... Rate This Content: NEXT >> December 24, 2013 Cardiac Rehabilitation Clinical Trials Clinical trials are research studies that ...

  11. Perceptions of cardiac rehabilitation patients, specialists and rehabilitation programs regarding cardiac rehabilitation wait times

    PubMed Central

    2012-01-01

    Background In 2006, the Canadian Cardiovascular Society (CCS) Access to Care Working Group recommended a 30-day wait time benchmark for cardiac rehabilitation (CR). The objectives of the current study were to: (1) describe cardiac patient perceptions of actual and ideal CR wait times, (2) describe and compare cardiac specialist and CR program perceptions of wait times, as well as whether the recommendations are appropriate and feasible, and (3) investigate actual wait times and factors that CR programs perceive to affect these wait times. Methods Postal and online surveys to assess perceptions of CR wait times were administered to CR enrollees at intake into 1 of 8 programs, all CCS member cardiac specialists treating patients indicated for CR, and all CR programs listed in Canadian directories. Actual wait times were ascertained from the Canadian Cardiac Rehabilitation Registry. The design was cross-sectional. Responses were described and compared. Results Responses were received from 163 CR enrollees, 71 cardiac specialists (9.3% response rate), and 92 CR programs (61.7% response rate). Patients reported that their wait time from hospital discharge to CR initiation was 65.6?±?88.4?days (median, 42?days), while their ideal median wait time was 28?days. Most patients (91.5%) considered their wait to be acceptable, but ideal wait times varied significantly by the type of cardiac indication for CR. There were significant differences between specialist and program perceptions of the appropriate number of days to wait by most indications, with CR programs perceiving shorter waits as appropriate (p?cardiac rehabilitation are prolonged compared with consensus recommendations, and yet are generally acceptable to most patients. Wait times following percutaneous coronary intervention in particular may need to be shortened. Future research is required to provide an evidence base for wait time benchmarks. PMID:22897912

  12. Output Interference in Recognition Memory

    ERIC Educational Resources Information Center

    Criss, Amy H.; Malmberg, Kenneth J.; Shiffrin, Richard M.

    2011-01-01

    Dennis and Humphreys (2001) proposed that interference in recognition memory arises solely from the prior contexts of the test word: Interference does not arise from memory traces of other words (from events prior to the study list or on the study list, and regardless of similarity to the test item). We evaluate this model using output

  13. Output regulation of nonlinear systems

    Microsoft Academic Search

    A. Isidori; C. I. Byrnes

    1990-01-01

    The problem of controlling a fixed nonlinear plant in order to have its output track (or reject) a family of reference (or disturbance) signal produced by some external generator is discussed. It is shown that, under standard assumptions, this problem is solvable if and only if a certain nonlinear partial differential equation is solvable. Once a solution of this equation

  14. x1 OUTPUT OUTPUT ROUTINES * 1. Output routines. This is the file that contains all the output routines fo*

    E-print Network

    van Leeuwen, Marc

    specific standard header files and `* *X Windows' programs are no exception. #include #include #include #include 3. There is one general header file pictures routines. This is the file that contains all the output routines fo* *r the pictures `X' envirom- ment

  15. Topical minoxidil: cardiac effects in bald man.

    PubMed Central

    Leenen, F H; Smith, D L; Unger, W P

    1988-01-01

    Systemic cardiovascular effects during chronic treatment with topical minoxidil vs placebo were evaluated using a double-blind, randomized design for two parallel groups (n = 20 for minoxidil, n = 15 for placebo). During 6 months of follow-up, blood pressure did not change, whereas minoxidil increased heart rate by 3-5 beats min-1. Compared with placebo, topical minoxidil caused significant increases in LV end-diastolic volume, in cardiac output (by 0.751 min-1) and in LV mass (by 5 g m-2). We conclude that in healthy subjects short-term use of topical minoxidil is likely not to be detrimental. However, safety needs to be established regarding ischaemic symptoms in patients with coronary artery disease as well as for the possible development of LV hypertrophy in healthy subjects during years of therapy. PMID:3191000

  16. Characterization of mitral valve prolapse with cardiac computed tomography: comparison to echocardiographic and intraoperative findings.

    PubMed

    Ghosh, Nina; Al-Shehri, Haliah; Chan, Kwan; Mesana, Thierry; Chan, Vincent; Chen, Li; Yam, Yeung; Chow, Benjamin J W

    2012-04-01

    A single imaging modality that can accurately assess both coronary anatomy and mitral valve (MV) anatomy prior to surgery may be desirable. We sought to determine the diagnostic accuracy of cardiac computed tomography (CT) to detect and characterize mitral valve prolapse (MVP) compared to echocardiography. Consecutive patients referred for 'single-source' cardiac CT for investigation prior to non-coronary cardiac sugery were identified. MV anatomy was assessed for MVP and results were compared to echocardiography and to intra-operative visual assessment of the MV. Comparison between the three modalities was performed at the per-patient, per-leaflet and per-scallop levels. A total of 67 consecutive patients that were referred for Cardiac CT prior to non-coronary cardiac surgery and were prospectively recruited into a Cardiac CT registry. Of these, 65 patients underwent cardiac surgery. 63 patients had echocardiography and 32 patients had intra-operative visual assessment of the mitral valve. Compared to echocardiography, cardiac CT had excellent sensitivity (92.6%) and specificity (97.1%) for the detection of any MVP, but had poor sensitivity (68.5%) for the detection of individual prolapsing scallop. Compared to intra-operative visual assessment of the prolapsing scallop, both cardiac CT and echocardiography had low sensitivity (58.1 and 78.1%, respectively). Cardiac CT was able to identify patients with MVP but had difficulty identifying the prolapsed scallops compared to echocardiography. Single-source CT may not be ready for characterization of individual mitral valve scallops. PMID:21604082

  17. Motion of the Esophagus Due to Cardiac Motion

    PubMed Central

    Palmer, Jacob; Yang, Jinzhong; Pan, Tinsu; Court, Laurence E.

    2014-01-01

    When imaging studies (e.g. CT) are used to quantify morphological changes in an anatomical structure, it is necessary to understand the extent and source of motion which can give imaging artifacts (e.g. blurring or local distortion). The objective of this study was to assess the magnitude of esophageal motion due to cardiac motion. We used retrospective electrocardiogram-gated contrast-enhanced computed tomography angiography images for this study. The anatomic region from the carina to the bottom of the heart was taken at deep-inspiration breath hold with the patients' arms raised above their shoulders, in a position similar to that used for radiation therapy. The esophagus was delineated on the diastolic phase of cardiac motion, and deformable registration was used to sequentially deform the images in nearest-neighbor phases among the 10 cardiac phases, starting from the diastolic phase. Using the 10 deformation fields generated from the deformable registration, the magnitude of the extreme displacements was then calculated for each voxel, and the mean and maximum displacement was calculated for each computed tomography slice for each patient. The average maximum esophageal displacement due to cardiac motion for all patients was 5.8 mm (standard deviation: 1.6 mm, maximum: 10.0 mm) in the transverse direction. For 21 of 26 patients, the largest esophageal motion was found in the inferior region of the heart; for the other patients, esophageal motion was approximately independent of superior-inferior position. The esophagus motion was larger at cardiac phases where the electrocardiogram R-wave occurs. In conclusion, the magnitude of esophageal motion near the heart due to cardiac motion is similar to that due to other sources of motion, including respiratory motion and intra-fraction motion. A larger cardiac motion will result into larger esophagus motion in a cardiac cycle. PMID:24586540

  18. Antifibrinolytics in cardiac surgery.

    PubMed

    Dhir, Achal

    2013-01-01

    Cardiac surgery exerts a significant strain on the blood bank services and is a model example in which a multi-modal blood-conservation strategy is recommended. Significant bleeding during cardiac surgery, enough to cause re-exploration and/or blood transfusion, increases morbidity and mortality. Hyper-fibrinolysis is one of the important contributors to increased bleeding. This knowledge has led to the use of anti-fibrinolytic agents especially in procedures performed under cardiopulmonary bypass. Nothing has been more controversial in recent times than the aprotinin controversy. Since the withdrawal of aprotinin from the world market, the choice of antifibrinolytic agents has been limited to lysine analogues either tranexamic acid (TA) or epsilon amino caproic acid (EACA). While proponents of aprotinin still argue against its non-availability. Health Canada has approved its use, albeit under very strict regulations. Antifibrinolytic agents are not without side effects and act like double-edged swords, the stronger the anti-fibrinolytic activity, the more serious the side effects. Aprotinin is the strongest in reducing blood loss, blood transfusion, and possibly, return to the operating room after cardiac surgery. EACA is the least effective, while TA is somewhere in between. Additionally, aprotinin has been implicated in increased mortality and maximum side effects. TA has been shown to increase seizure activity, whereas, EACA seems to have the least side effects. Apparently, these agents do not differentiate between pathological and physiological fibrinolysis and prevent all forms of fibrinolysis leading to possible thrombotic side effects. It would seem prudent to select the right agent knowing its risk-benefit profile for a given patient, under the given circumstances. PMID:23545866

  19. Cardiac tamponade in Taiwan.

    PubMed

    Wang, M L; Liao, W B; Bullard, M J; Lin, F C; Lin, P J; Chiang, C W; Liaw, S J; Chiang, C H

    1997-09-01

    We retrospectively reviewed all of the patients who were treated for cardiac tamponade at Linkou Chang Gung Memorial Hospital between January 1991 and December 1995. There were a total of 112 patients (57 males, 55 females) with a mean age of 51 +/- 14 years (53 +/- 15, 49 +/- 13, respectively). Dyspnea was the most common complaint (85%). The mean blood pressure was 129 +/- 24/78 +/- 17 mmHg, and only 8% had a systolic blood pressure of less than 90 mmHg. Sinus tachycardia was the most frequent electrocardiographic finding (72%, 62/86). Diffuse low voltage was noted in 35% (30/86) of the patients and electrical alternans was seen in 17% (15/86). The mean volume of pericardial effusion was 610 +/- 263 ml. Sixty-five percent of the pericardial effusions were bloody, 31% were serosanguineous, 2% were purulent and 2% were chylous. Overall, 54.5% of the patients had malignant diseases. Of the 61 patients who died, 79% had malignancies. Thirty-five (57%) of these 48 patients had lung cancer. The mean survival time from emergent pericardiocentesis was 3.4 months. In conclusion, non-traumatic cardiac tamponade had a poor prognosis because most patients had malignant etiologies. There is still no definitive treatment for recurrent malignant pericardial effusion-induced cardiac tamponade. Percutaneous pericardiocentesis as clinically required may be the most appropriate treatment, since it is questionable whether such subjects should be subjected to the unnecessary pain and suffering associated with an operative procedure, considering their short mean survival time. PMID:9293407

  20. Adaptive Neural Output Feedback Control of Output-Constrained Nonlinear Systems With Unknown Output Nonlinearity.

    PubMed

    Liu, Zhi; Lai, Guanyu; Zhang, Yun; Chen, Chun Lung Philip

    2015-08-01

    This paper addresses the problem of adaptive neural output-feedback control for a class of special nonlinear systems with the hysteretic output mechanism and the unmeasured states. A modified Bouc-Wen model is first employed to capture the output hysteresis phenomenon in the design procedure. For its fusion with the neural networks and the Nussbaum-type function, two key lemmas are established using some extended properties of this model. To avoid the bad system performance caused by the output nonlinearity, a barrier Lyapunov function technique is introduced to guarantee the prescribed constraint of the tracking error. In addition, a robust filtering method is designed to cancel the restriction that all the system states require to be measured. Based on the Lyapunov synthesis, a new neural adaptive controller is constructed to guarantee the prescribed convergence of the tracking error and the semiglobal uniform ultimate boundedness of all the signals in the closed-loop system. Simulations are implemented to evaluate the performance of the proposed neural control algorithm in this paper. PMID:25915964